WORKS OF HALBERT P. GILLETTE EARTHWORK AND ITS COST; A HANDBOOK OF EARTH EXCAVATION. 1350 pages, illustrated, flexible binding, 4% x 7 in $6.00 ROCK EXCAVATION ; METHODS AND COST. 840 pages, 184 illustrations, flexible binding, 4% x7 in. .$6.00 CLEARING AND GRUBBING ; METHODS AND COST. 240 pages, 67 illustrations, 4% x 7 in $2.50 HANDBOOK OF COST DATA. A reference book, giving methods of construction and actual costs of materials and labor on numerous civil engineering works. Vol. I, 1878 pages, illustrated, flexible binding, 4% x 7 in $6.00 Vol. II, in preparation, ready early in 1920. HANDBOOK OF MECHANICAL AND ELECTRICAL COST DATA. By Halbert P. Gillette and Richard T. Dana. 1750 pages, illustrated, 4% x7 in., flexible binding. .. .$6.00 COST KEEPING AND MANAGEMENT ENGINEERING. By Halbert P. Gillette and Richard T. Dana. A treatise for engineers and contractors. 360 pages, 184 illustrations, cloth, 6x9 in $4.00 CONCRETE CONSTRUCTION ; METHODS AND COST. By Halbert P Gillette and Charles S. Hill A treatise on concrete and reinforced concrete structures of every kind. 700 pages, 306 illustrations, cloth, 6 x 9 in $5.00 ROAD CONSTRUCTION ; METHODS AND COST. By Halberl P. Gillette and Charles R. Thomas In preparation, over 800 pages, illustrated, flexible bind- ing, 4% x 7 in. EAETHWORK AND ITS COST A HANDBOOK OF EARTH EXCAVATION BY H ALBERT POWERS GILLETTE Editor of Engineering and Contracting Member American Society of Civil Engineers. American Institute of Mining Engineers. American Association of Engineers, Western Society of Engineers. THIRD EDITION McGRAW-HILL BOOK COMPANY, INC. 239 WEST 39xn ST., NEW YOHK LONDON: HILL PUBLISHING COMPANY, LTD. 6 AND 8 BOUVERIK ST., E. C. 1920 Copyright, 1920 CLARK BOOK COMPANY, INC. tetttov ii^iJir-Lurn PREFACE AND INTRODUCTION With respect to books on " methods and costs," three errors are commonly made by those who might profit from such books. First, that much of the text is out of date when it is ten or more years old. Second, that published unit costs are of little or no use, especially if wages and prices have changed since the pub- lication. Third, that the study of methods and " tricks of the trade " is not a very good mental training. Taking the last of these errors first, we find that many profes- sors of civil engineering still have a somewhat exaggerated ad- miration for " general principles," coupled with an equally exag- gerated contempt for " practical details " as mental food for their students. Professors of mining engineering have erred in this manner with much less frequency, probably because their primary aim has been to train men for managerial positions rather than as designers. It was my good fortune to take a course in mining engineering under Prof. Henry S. Munroe at Columbia Univer- sity. Part of that course consisted of lectures on the methods and costs of excavation, followed by two summers spent in mining in Michigan and Pennsylvania. Thus I formed the habit of observ- ing, analyzing and comparing excavation methods and costs under varying conditions. To the formation of that valuable habit, and an extension of it to other kinds of construction work, I owe in large measure my subsequent success in the field of civil engi- neering. I mention this to indicate the mental-training value of collecting and analyzing cost data. If some professors of civil engineering are making a mistake in not training students as analysts of costs and observers of meth- ods, an equally serious mistake is made by contractors and super- intendents of construction. These men are justly proud of their " practical knowledge," by which they usually mean only the knowledge gained by their own experience. They usually fail to realize that ttie experiences of hundreds of other men, just as " practical " as they are, have been recorded in print, often in very great detail. Surely it can not be their contention that printed information as to money-saving methods and machines is useless to "practical men"; yet, were we to judge merely by their ten- dency not to read such matter, we should conclude that among PREFACE AND INTRODUCTION " practical men " there is scant respect for the printed page. I prefer to think that this seeming lack of respect is ascribable mainly to bad habits rather than to illogical thinking. " Prac- tical men " usually have not formed the good habit of systemat- ically reading practical books and articles. A few still labor under the delusion that there are no such books and articles, but most of them are habituated to field work, and not at all habitu- ated to book work. The trouble lies there, and the cure of it if cure there is to be is in the medicine that such books as this contain. As to the out-of-dateness of old text, and particularly of old cost data: Sixteen years ago the first edition of this book was published. I have retained three-fourths of ihat old book in this third edition, yet most of the matter in that first edition was fully ten years old when the first edition was printed. As one example, I have used cost data published by Elwood Morris in 1841, because neither the tools (drag scrapers) nor the methods described by him have changed materially. In another instance, and for a similar reason, I have referred to cost data published by George J. Specht in 1885; his data related to fresno scraper work, and are as useful today as they were 35 years ago. In spite of the fact that new machines and improved methods are constantly being introduced, old devices and methods fre- quently continue to be economic under certain conditions. The Chinese are credited with the invention of the wheelbarrow count- less centuries ago, yet it remains a useful tool to this day. I venture to say that if we were to find ancient but complete Chi- nese cost data on shoveling and wheeling earth, we could apply those data now. Yet common labor wage rates in China might have been only a twentieth or a thirtieth of what they are in America today. The point that I wish to make is this: Complete and well-analyzed cost data contain the number of hours or days work per unit (such as the cubic yard) of work done, together with a statement of conditions. Hence any change in wage rates does not destroy the value of such cost data, for it is a simple matter to substitute existing wage rates and calculate the present cost. In the preface of the first edition I said: " There are few engineering works of magnitude that do not involve the excavation of earth. Indeed, the cost* of earthwork forms one of the greatest of cost items in canal, in reservoir and in railway construction, nor is it an inconsiderable item in the construction of roads, sewers or water works. What will this excavation cost? This is a question that the engineer first asks himself in making his preliminary estimates. Later the same PREFACE AND INTRODUCTION. question confronts the contractor. To the engineer an erroneous answer may mean loss of reputation; to the contractor it as- suredly means ruin where the work is extensive. A glance at the wide range in contract bids for most earthwork jobs will convince any one that few contractors do more than guess at costs. While the numberless engineering structures that have cost more than the preliminary estimates prove quite as conclusively that engi- neers too often guess also. " In this the iirst published volume treating of earth economics in a comprehensive way, I have given all that my own notes could furnish and all that I have found in print in American technical literature. But I have not confined the exposition to a bare re- cital of facts and figures, since the principal aim has been to outline rational methods and rules to be used in cost calculation." Shortly after the first edition was published, a non-technical friend remarked : " I am amazed at your being able to find enough matter to fill 200 pages on dirt." Whether his amazement would now be six-fold as great as then, one can but guess. His surprise, however, is typical of that of almost every non-technical man on first looking into the literature of a narrowly technical subject like earthwork. I could easily have doubled the size of this book, without going outside the best articles that have been published during the last thirteen and one-half years in Engineering and Contracting under my editorial direction. But the limited de- mand for expensive, large books of this character necessitates a restriction in size. However, quite a complete bibliography is given at the end of each chapter, by which readers may be guided to many excellent articles on earthwork not abstracted in this book. For assistance in abstracting articles and compiling data for this book, I wish to acknowledge my indebtedness to Arthur P. Ackerman and H. C. Lyons. HALBERT P. GILLETTE. Chicago, 111., Feb. 23, 1920. 425852 TABLE OF CONTENTS CHAPTER PAGES I PROPERTIES OF EARTH 1-18 Kinds of Earth, 1; Weight of Soils, 4; Voids in Dry Earth. 5; Frost Penetration, 6; Angle of Repose, 7; Greatest Height of Vertical Bank, 7 ; Shrinkage, 8 ; Swelling of Newly Ex- cavated Material, 10; Effect of Water on Clay Shrinkage, 13; Shrinkage of Rolled Earth Embankment, 14; Summary, 17; Bibliography, 18. II MEASUREMENT, CLASSIFICATION AND COST ESTI- MATING 19-40 Earthwork Definitions, 19 ; Measurement, 22 ; Legality of Methods of Calculating Earthwork, 23 ; Classification of Ex- cavation, 25 ; Specifications for Classification of Excavation, 26; A Classification According to Difficulty of Picking, 27; Railway Specifications for Classifications, 29 ; The Am. Ry. Eng. and Manit. W. Asso. Classification, 37; Factors Affecting Cost of Earthwork, 37; Bibliography, 40. III BORING AND SOUNDING 41-84 Prospecting or Testing Earth, 41 ; Importance of Prospect- ing Excavations, 41 ; Sounding, 42 ; Devices for Sounding and Sampling, 42 ; Wash Borings, 46 ; Rigs for Wash Bor- ings, 46 ; Examples of Cost of Wash Borings, 52 ; Instruc- tions for Inspectors on Wash Boring, Catskill Aqueduct, 61 ; Boring with Augers, 64 ; Auger Boring Devices, 64 ; Auger Boring Costs, 69 ; Auger Boring with Empire Drill, 76 ; Post- Hole Diggers, 80; Cable Drills, 81; Test Pitting, 83; Test Trenches, 83 ; Bibliography, 84. IV CLEARING AND GRUBBING 85-93 Factors in Clearing and Grubbing Costs, 85 ; Types of Roots, 86 ; Estimating Costs of Clearing and Grubbing, 86 ; Effects of Method of Excavation on Cost, of Grubbing, 88 ; Loss of Material Due to Grubbing, 89 ; Clearing and Grubbing Methods, 91 ; Amount of Dynamite Used in Stump Blasting, 91; Bibliography, 93. V LOOSENING AND SHOVELING EARTH .... 94-151 Methods of Loosening the Soil, 94; Cost of Picking, 94; Shoveling, 96; Table of Cost of Digging and Shoveling, 97; Sizes of Hand Shovels, 98 ; Types of Shovels, 104 ; Cost Data ix x CONTENTS CHAPTER PAGES on Hand Excavation, 106; Loosening and Shoveling Sticky Clay, 107; Rating Table for Excavation with Pick and Shovel, 110; Examples of Cost of Hand Excavation, 115; Plows and Plowing, 119; Dynamometer Test on Plows, 123; Traction Plowing, 124; Loosening with Explosives, 126; Excavating Holes with Explosives, 128; Ditching with Dynamite, 132; Treatment of Frozen Ground, 140; Bibliography, 151. VI SPREADING, TRIMMING AND ROLLING EARTH . 152-164 Spreading, 152; Surfacing and Dressing Earthwork, 153; Trimming, 154; Trimming and Seeding Slopes, 156; Ram- ming and Rolling, 157; Sprinkling, 157; Smoothing and Leveling Farm Land, 159; Smoothing Devices Used in Pre- paring Land for Irrigation, 160 ; Bibliography, 164. VII HAULING IN BARROWS, CARTS, WAGONS, AND TRUCKS . 165-229 Lead and Haul, 165; Types of Wheelbarrows. 168; Ca- pacity of Wheelbarrows, 169; Examples of Wheelbarrow Work, 170; Station Work on a Railway Embankment. 173; Carts, 175; Cost with Carts, 177; Examples of Work with Carts, 178; Types of Wagons, 179; Dump Boxes, 182; Wagon Work, 184; Rule for Cost of Work with Wagons, 186; Work of Teams, 187; Use of Snatch Teams, 188; Mov- able Hopper for Excavated Material, 190 ; Car Side Wagon Loaders, 192; Example of Wagon Work. 197; Traps for Loading Wagons, 199 ; Handling Teams with a Jerk Line, 208; Wagon Train Haulage with Motor Trucks, 210; Types of Tractors, 215; Analysis of Hauling Costs, 224; Bibli- ography, 229. VIII METHODS AND COSTS WITH ELEVATING GRADERS AND WAGON LOADERS 230-240 Rule for Cost with Elevating Grader, 231; Widening Wheels of Graders for Work Over Soft Ground, 234; Method of Using Elevating Graders on Earth Roads, 234 ; Examples of Elevating Grader Work. 235; Tractors for Pulling Grad- ers, 243; Various Types of Wagon Loaders, 244; Bibli- ography, 249. IX METHODS AND COSTS WITH SCRAPERS AND GRADERS 250-334 Buck Scrapers, 250; Drag Scrapers, 254; Examples Drag Scraper Work, 256 ; Pushing Scrapers, 259 ; Fresno Scraper, 261; Examples of Fresno Scraper Work, 264; Wheel Scrapers, 274; Hints on Handling Wheelers, 277; Examples of Wheel Scraper W T ork, 280; Economic Handling of Earth in Wheel and Fresno Scrapers, 300; Doubletrees and Eveners, 306, 307; Bonus System on Scraper Work, 308; Keeping CONTENTS xi CHAPTER PAGES Cost of Scraper Work, 310; Four Wheel Scrapers, 312; Ex- amples of Work and Costs with Four Wheel Scrapers, 317; Road Graders, 320 ; Smoothing Machines, 322 ; Examples of Work with Road Graders, 323; Tractor Grading, 327; Earth Moving Methods and Equipment for Road Construction, 331 ; Bibliography, 334 X METHODS AND COSTS WITH CABS . . . . . . 335-386 General Types of Contractor's Cars, 335; Track Throwing Car, 339; Switch for Narrow Gauge Tracks, 339; Use of Cars, 341; Cars Moved by Hand, 344; Horse Drawn Cars, 345 ; Rule for Cost of Work with Cars, 346 ; Comparative Cost with Wheelers and Cars, 347; Motor Truck Hauling In- dustrial Railway Cars, 348 ; Hauling with Dinkeys, 349 ; Types of Light Locomotives, 352 ; Resistance to Rolling Fric- tion, 352; Water and Fuel Consumption of Locomotives, 354; Examples of Cost with Horse Drawn Cars, 356; Examples of Hauling Costs with Dinkeys, 358; Hauling with Gasoline Mine Locomotives, 363; Mine Haulage with Mules and Elec- tric Locomotives, 364; Central-Control Electric Car Haulage, 366; Cars Hauled by Cables, 368; Life of Cable on Engine Incline, 372; Car Unloaders, 372; Method of Handling Un- loader Plow Cables, 375; Recommendations for Using Cars on Steam Shovel Work, 376; Lloyd Unloading Machine, 378; Comparative Cost of Hauling Earth in Flat and Dump Cars, 381; Unloading Cars to Bins in Small Space, 382; Unload- ing Cars by Sluicing, 384; Spreaders, 384; Cost of Spread- ing with Jordan Spreader, 385; Bibliography, 386. XI METHODS AND COSTS WITH STEAM AND ELEC- TRIC SHOVELS 387-557 Types of Shovels, 387; How to Handle Steam Shovel Plant, 387; Widening Railway Cuts, 389; Cutting Down Railway Grades, 391; Railway Construction Work, 894; Canal Ex- cavation, 396 ; Analysis of Costs of Steam Shovel Work, 400, 403 ; Repairs to Steam Shovels, Cars, and Locomotives on the Panama Canal, 413 ; Prices of Standard Railway Shovels, 418 ; Steam Shovel Dippers and Dipper Trips, 420 ; Rail Clamps, 424; Specifications for Steam Shovel Construction, 428; Rec- ommended Practice in Steam Shovel Operation, 430 ; Man- agement of Steam Shovel Work 434 ; Brief Examples of Steam Shovel Work, Time Study Costs, 440-466; Hints on Steam Shovel Work, 466; Moving Steam Shovels, 472 ; Examples of Cost Work, with Standard Railway Shovels, 474; Non-Revolving Traction Shovels, 507; Examples of Cost of Work with Non-Revolving Traction Shovels, 508 ; Large Revolving Shovels, 510; Railroad Ditchers and Locomotive Crane Shovels, 515; Handling Material with Double Ditcher Train, 515; Small Revolving Shovels, 516; Examples of Cost of Work with Small Revolving Shovels, 519; Electrically Oper- xii CONTENTS CHAPTER PAGES ated Shovels, 541; Comparison of Steam and Electrically Op- erated Shovels, 543 ; Power Consumption of Electric Shovels, 545; Examples of Cost of Work with Electric Shovels, 547; Excavating Machines of the Steam Shovel Type, 554; Bibli- ography, 557. XII METHODS AND COSTS WITH GRAB BUCKETS AND DUMP BUCKETS 558-574 Classification of Buckets, 558 ; Skips, 558 ; Foundation Ex- cavation with Derricks and Car Bodies, 559; Trunion Buck- ets Loading Wagons through a Hopper, 560; Bottom Dump Buckets, 565 ; Three Types of Buckets on Sewer Work, 565 ; Orange-Peel Buckets, 567; Examples of Cost of Work with Orange-Peel Buckets, 568; Clam Shell Buckets, 570; Ex- amples- of Cost of Work with Clam Shell Buckets, 571; Bibli- ography, 574. XIII METHODS AND COSTS WITH CABLEWAYS AND CON- VEYORS 575-014 Economic Use of Cableways, 576; Cableway Costs, 576; Cableway Systems, 576; Coasting Cableway, 583; Balanced Cable Crane, -585 ; Combination Cableway and Derrick, 586 ; Life of Main Cable, 586; Skip Dumping Device, 587; Drag- line Cableway Excavators, 588 ; Cableway Scraper Excavators, 589; Cost of a Tower Scraper Excavator, 594 ; Examples of Cost of Work with Cableways, 596; Dragline Cableway on Levee Work, 603 ; Belt Conveyors, 603 ; Capacity of Belt Con- veyor, 604; Life of Belt Conveyor, 604; Examples of Cost of Work with Belt Conveyors, 605 ; Bucket Conveyors, 613 ; Bibliography, 614. XIV METHODS AND COSTS WITH DRAGLINE SCRAPERS 615-668 Bottomless Power Scrapers, 615; Overburden Stripping with Bottomless Bucket, 616; Power Scraper and Wagon Loader, 619; Leveling Ground with Power Scraper, 623; Loading Wheel Scrapers with an Engine, 627; Walking and Caterpillar Traction for Draglines, 633 ; Dredging Gravel with a Weeks Bucket, 639 ; Dragline Excavator Buckets, 643 ; Planking for Dragline Work over Soft Ground, 645 ; Ex- amples of Cost of Work with Dragline Excavators, 648 ; Elec- tric Dragline Excavators, 657; Steam and Electric Draglines on N. Y. Barge Canal, 662; Examples of Cost of Work with Electric Draglines, 663; Bibliography, 668. XV METHODS AND COSTS OF DREDGING 669-765 Classification of Dredges, 669 ; Capacities of Dredges, 669 ; Cost per Ton of Dredge Construction, 669 ; Relative Merits of Different Types of Dredges, Selecting a Dredge, 671 ; CONTENTS xi'ii CHAPTER PAGES American and European Practice Compared with Regard to Dredging , 677; Government Dredging vs. Contract Dredging, 677 Bucket Dredges, 678; Storage Drum for Dredge Cable, 681 Examples of Cost of Work with Clam Shell Dredges, 681 Examples of Cost of Work with Orange-Peel Dredges, 685 Dipper Dredges, 686 ; Conditions Favorable to the Dip- per Dredge, 688 ; Cost of a Dipper Dredge, 688 ; Aligning a Dredge in a Canal, 690 ; Dredging with Steam Shovel Mounted on Hull, 693 ; Hydraulic Jet Equipment for Leveling Spoil Banks, 695 ; Examples of Cost of Work with Dipper Dredges, 667; Ladder Dredges, 704; Dredging Silt Bars with Ladder Dredge, 705 ; Trestle Filling with Ladder Dredge, 708; Examples of Cost of Work with Ladder Dredges, 709; Gold Dredges, 718 ; Hydraulic Suction Dredges, 718 ; Float- ing Pipe Line, 720; Depth at which Suction Dredge Can W T ork, 721; Hydraulic Pipe Line Dredge Compared to Clam Shell Dredge, 721; Examples of Cost of Work with Sea Going Hopper Dredges, 724; Examples of Cost of Work with Hy- draulic Pipe Line Dredges, 733 ; Cost, Life, and Repairs of Barges, Tow-boats and Dredges, 753 ; Cost of Year's Opera- tion of Marine PlaniJ for Construction of Lincoln Park Extension, Chicago, 759 ; Bibliography, 764. XVI METHODS AND COST OF TRENCHING .... 766-902 Definitions of trench and ditch, 766 ; Trench Excavation by Hand, 767; Examples of Cost of Trenching by Hand, 772; Trenching for Tile Drains, 775 ; Derricks and Locomotive Cranes on Trench Work, 778; Examples of Cost of Trenching with Derricks, 779 ; Examples of Cost of Trenching with Orange-Peel and Clam Shell Buckets, 783; Trenching with Dragline Excavator, 786; Trenching with Steam Shovels, 786; Examples of Cost of Work with Steam Shovels, 795; Trenching with Special Machines, 807; Examples of Cost with Carson Trench Machine, 810; Examples of Cost with Potter Trenching Machine, 813; The Moore Trench Machine, 818; The Parsons Trench Excavator, 821; P. & H. Trench Ex- cavators, 825 ; Examples of Cost of Work with P. & H. Trench Excavators, 827; Examples of Cost with Austin Trench Excavators, 833; The Buckeye Traction Ditcher, 839; Cost of Work with Buckeye Traction Ditcher, 839; The Hov- land Tile Ditcher, 843 ; Trench Excavating by Hydraulicking, 845; Methods of Sheeting and Bracing, 846; Examples of Cost of Sheeting, 853; Methods and Costs of Trench Pump- ing, 862 ; Examples of Cost of Pumping, 863 ; Treatment of Quicksand, 868 ; Bleeding Wet Sand, 870 ; Backfilling Trenches, 884; Methods and Costs of Backfilling, 887; Back- filling Machines, 892; Puddling Backfill, 896; Cost of Back- filling and Tamping, 897; Tamping Machine, 899; Rolling Backfill, 901; Bibliography, 902. xiv CONTENTS CHAPTER PAGES XVII DITCHES AND CANALS 903-1003 Types of Ditches, 903 ; Reducing the Cost of Drainage Excavation, 905 ; Special Ditching Machines, 909 ; Examples of Cost of Operating Wheel Type Excavators, 910; Tem- plate Excavators, 915; Walking or Land Dredges, 921; Ditching with Capstan Plows, 927; Ditching by Explosives, 933; Ditch Excavation by Scrapers, 937; Examples of Cost of Irrigation Canals, 938 ; Use of Elevating Graders in Ditching, 947 ; Examples of Ditching with Dragline Exca- vators, 950; Floating Dredges for Ditching, 954; Cutting 1 to 1 slopes with a Dipper Dredge, 956; Ditch Excavation by Natural Erosion, 962; Railroad Ditcher, 965; Examples of Use of Railway Ditchers, 966 ; Ditching with Electrically Op- erated Railway Ditcher, 969; Highway Ditches, 972; Gopher Ditches, 973; Maintenance of Ditches and Canals, 974; Grades Required for Self-Cleaning Ditches, 975 ; Combat- ing Weeds Along Irrigation Canals, 977; Navigable Canals, 980; The Chicago Drainage Canal, 981; New York State Barge Canal Work, 986; Work on North Shore Channel, Chi- cago, 994; Cost of Excavation on Colbert Shoals Canal, Ala., 1001; Bibliography, 1003. XVIII HYDRAULIC EXCAVATION AND SLUICING . . . 1 004-1 08G Methods of Hydraulic Excavation, 1004; Hydraulic Giants, 1004; Bed-Rock Sluices, 1004; Carrying Capacity of Water, 1005 ; Volume of Water for Hydraulicldng, 1009 ; Ditches and Flumes, 1009; Hydraulic Elevator Work in Alaska, 1013; Pipe lines for Hydraulic Mining, 1016; Simple Tim- , ber Flume, 1019; Sluicing Sand and Gravel in Steel-lined Flumes, 1023; Methods of Working Placer Gravel, 1026; Range of Cost of Hydraulic Mining, 1032; Grading River Banks with Water Jet, 1036; Stripping Gravel Pits by Hy- draulic Methods, 1038 ; Stripping Shale Pits, 1043 ; Removing a Land Slide by Hydraulic Jetting, 1048 ; Excavating a Canal by Hydraulicking, 1050 ; Hydraulic Fills on Railway Trestles, 1051; The Sheerboard Method of Retaining Wet Earth, 1056; Hydraulic Methods of Building Dams, 1058; Hydraulic Grading of Westover Terraces, Portland Ore'., 1075 The Denny Hill Regrade, Seattle, 1081; Bibliography, 1086. XIX ROAD AND RAILROAD EMBANKMENTS . . . 1087-1146 Method of Determining Subsidence and Shrinkage, 1088; Tamping Roller for Embankments, 1090; Road Work with Power Machinery, 1091; Road Embankments over Marshy Ground, 1092 ; Compression of Marsh Soil, 1098 ; Railway Embankments, 1098; Subsidence Investigations of Railway Embankments, 1099; Temporary Trestles, 1102; Movable Trestles for Bank Construction, 1105; Suspension Bridge Trestles, 1106; Dragline Excavators for Railway Grading, 1115; Building Railway Embankments with Hydraulic CONTENTS xv CHAPTER PAGES Dredges, 1116; Filling Trestles by Sluicing, 1119; Support- ing Construction Track on Ice, 1120; Placing Railroad Fill from Floating Trestle, 1121; Cost of Widening Embank- ments, 1123 ; Cost of Transporting Men, Tools and Supplies for Railway Grading, 1130; Cost of Railway Grading by Steam Shovel. 1132; Cost of Raising a Railway Embank- ment, 1136; Manner of Filling a 75 Ft. Trestle, 1139; Drag and Wheel Scraper Work on North Carolina Railway, 1140; Bibliography, 1145. XX DESIGN AND CONSTRUCTION OF EARTH DAMS . 1147-1246 Design of Earth Dams, General Considerations, 1147; Per- meability of Concrete and Puddle Walls in Earth Dams, 1151; Examples of Types of Earth Dams, 1152; Determining the Percolation Factor, 1163; Shrinkage of Earth in Dam, 1164; The Tabeaud Dam, 1165; Use of Goats for Com- pacting Puddle, 1170; Earth Dam Compacted by Irrigation FJooding, 1171; Elevating Graders on the Stanley Lake Dam, 1173; Embankment for an Oil-Storage Reservoir, 1175; Rolling Reservoir Embankment Slopes, 1178; Cost of Em- bankment and Puddle for a Settling Basin, 1181; Earth Dam at Springfield, Mass., 1182; Belle Fourche Dam, Excavating Methods and Costs, 1191; Cold Springs Earth Dam, Oregon, 1197; Construction of the Kachess Lake Dam, 1202; Con- structing Embankment for Hill View Reservoir, N. Y., 1206; Dams of Boulder Filled Wire Baskets, 1208 ; Temporary Hy- draulic Fill Dam Across- the Colorado River, 1210; Cost of Earth Embankment with Gravel Facing, 1213; Placing Pud- dle in a Cofferdam by Pumping, 1215; Embankment for the Yale Bowl, 1217; Hydraulic Fill Dams, 1220; Hydraulick- ing the Concully Dam, 1221; Hydraulicking the Bear Creek Dam, 1227; Dam Construction by Cars and Hydraulicking, 123 f ; Examples of Other Dams Built by Hydraulicking, 12 .'8 ; Accidents to Earth Dams, 1243; Bibliography, 1245. XXI DIKES AND LEVEES 1247-1275 The Location of Levees, 1247; Design of Dikes for Salt March Reclamation, 1248; Levee Sections on the Mississippi and Sacramento Rivers, 1249; Enlarging and Slope Walling a Levee on the Wabash River, 1251; Levee Construction by Dragline Excavators, Little River Drainage District, Mo., 1252; Levee Construction in Texas with 'Draglines, 1254; Machines for Building Levees, 1255 ; Building Levees with Hydraulic Dredge, 1262 ; Sand Core Levees in California, 1272; Bibliography, 1275. XXII SLIPS AND SLIDES 1276-1327 General Discussion, 1276; The Cause and Cure of Slides, 1277; Land Slide at Mount Vernon, 1279; Extensive Earth xvi CONTENTS CHAPTER PAGES Slip Near Hudson, N. Y., 1279; Land Slide at Bulls Bridge Hydro-Electric Plant, 1280; Remarkable Land Slide at Port- land, Oregon, 1284; Treatment of Railway Slides, 1288; Preventing Slips on Railways, 1290; Drainage Tunnel to Stop Sliding Clay, 1292; Treatment of a Wet Cut, 1294; A Scoop Car for Handling Railway Slides, 1297; Holding Slides by Piles, 1300 ; Stopping a Slide by the Use of Ex- plosives. 1305; European Railway Practice for the Preven- tion of S'ides, 1306 ; Stopping Slips on the Nottingham and Melton Ry., 1321; Improving Sliding Material by Burning, 1323 ; The Drainage of a German Railway Embankment, 1325; Bibliography, 1327. . :jj CHAPTER,^ X 1 - : PROPERTIES OF EARTH Composition of Earth. Earths or soils are the insoluble resi- dues from the weathering of rocks. Soils from whatever source derived are mixtures of sands and clays, and they differ princi- pally in the relative proportions of sand or siliceous material to the clay or argillaceous matter, and in the size of the grains. Residual soils are more varying in composition than soils that have been transported by water. The further and oftener a soil has been transported the more complete the separation of the clay from the sand. Clay is generally the result of the decomposition and conse- quent hydration of feldspathic rocks, especially granite and gneiss. Clays from these sources usually contain more or less siliceous material; and, if this is separated, the residuum is found to consist of hydrated silicate of alumina with more or less lime, oxides of iron, magnesia, and alkalies. All soils found near the surface of the earth contain more or less organic matter. Clay is often the residuum of limestone, the calcite having been dissolved and leached out. Marly soils are the remains of old shell beds that have decomposed in this way. Earths, therefore, are compositions mainly of silica and sili- cates of aluminum and other metals. Kinds of Soils. Soils are sometimes named from the rock from which they have been derived; thus, a soil resulting from decomposition may be a granite soil, limestone soil, etc. More often, however, soils that have been transported are named after the agencies involved in their transportation; as glacial soils; or from their position, as terrace soils; or from their characteristics, as sandy or clayey soils. The term loam is usually applied to mixtures of sand and clay containing organic matter. When the principal constitu- ents of a loam is clay it is termed clayey loam, and when sand predominates, sandy loam. Many local terms are applied to soils, and there is much varia- tion in the use of earth and soil nomenclature, thus clay is called gumbo. Some of the terms applied to earth and soils by writers on earthwork are as follows: Adobe is the name given to a calcareous clay of a general gray brown or yellowish color, very fine grained and porous. This material forms the soil of a large portion of the rainless region of the United States in Colorado, Utah, Nevada, Southern California, Arizona, New Mexico, and Western Texas. It ia derived from the waste of surrounding mountain slopes. 1 2 _ t HANDBOOK OF EARTH EXCAVATION Alluvial Soil is river-borne material consisting of mixtures of sand and clay in varying degrees of fineness. It is usually loose in texture. Black-waxy is a term applied to certain very fertile soils in Texas. They are a mixture of clay and organic matter, black in color and heavy to work. Buck Shot Clay is a clay containing small concretions cemented with calcareous or ferrous material. These are about the size of buck- shot. Bull-Liver is a term applied to a mixture of very fine sand, pulverized limestone and water, encountered in the excavations for the Chicago Drainage Canal. (E. R. Shanable, in Trans. Asso. Eng. Soc., June, 1895.) This material when in place was very tough and difficult to excavate. Catlinite, or Indian pipe stone, is an indurated clay found in the Dakotas. Clay is a mixture of finely divided silicates of aluminum, iron, magnesium, calcium, and other metals. It seldom occurs without a small percentage of sand which has a greater effect on its characteristics than its chemical composition. Glacial Soil, is an uneven mixture of clay, sand, gravel and boulders, carried and deposited by prehistoric glaciers. It is usually loose in texture but is sometimes very tough and even cemented. Gravel is any soil which Is composed chiefly of small stones. No definite line can be drawn between sand, gravel, and boulders ; but, in general, material passing a y^-in. screen would be counted sand, and stones too large to handle on a hand shovel would be called bo Iders. Pure gravel is loose in texture and easy to work. It often occurs with such a mixture of finer materials that each stone is tightly embedded. In this condition it w T ill require picking. Gumbo is a fine clay. It is extremely sticky and difficult to handle when wet. Hardpan is the term applied to any extremely compact soil that is difficult of excavation. Geologically it is rock in the process of formation. It may be a clay that has become hardened by heat or pressure, or an incipient shale, or a sand or gravel that has been partially cemented by small amounts of iron oxide or carbonate of lime. Glacial deposits, consisting as they often do of nests of large size gravel and boulders in dense sandy clay beds, are often spoken of as hardpan. Most hardpans do not soften under the action of water when first taken out of the p't, but after being exposed to the air until dry they crumble rapul'y i to ^jniite fragments when submerged. PROPERTIES OF EARTH 3 Kaolin is pure aluminum silicate. Deposits of relative purity are worked for potters' clay. Later-it e is a red furruginous residual clay found in tropic and semi-tropic regions. Loam is a mixture of sand and clay containing organic matter. It exists practically everywhere as the top soil which supports vegetation. Loess is a clay, similar to adobe covering wide areas in the Mississippi Valley. It is in general wind-borne material. Marl is a clay containing much calcium carbonate, the result of the decomposition of old shell beds. Muck is a term applied to a variety of material. Thus in tunneling and many other forms of excavation the excavated material is called muck, The term is best applied to the slimy mud from pond bottoms and to similar material. Muskeg is the mixture of mud, peat, and moss that occurs in wide areas in the swamps of Canada and northern United States. Peat is decayed vegetable matter. Geologically it is coal in process of formation. It is light when dried, but always occurs in a water soaked condition. Quicksand has been defined as a mixture of fine sand with such proportions of clay and loam as will enable the mass to retain water. The true quicksand, however, is an argillaceous material containing little or no silica or grit, and is usually leaden in color in its natural, water soaked state, and mainly white when thoroughly deprived of water. This material when wet and trampled upon begins to quake; it is therefore often called quakesand. If after having reached a condition where it quakes, it is left quiescent for a few hours, the particles settle down and expel the water, and it again becomes firm. Three rules to be observed in excavating quicksand are as follows : ( 1 ) The water must be removed promptly and thor- oughly; (2) the excavation must be made with the utmost dis- patch; (3) the material must not be disturbed after it begins to quake. When quicksand is encountered, ample dredging and pumping facilities should be provided. The pumps should be capable of lifting sand as well as water, and for this reason pumps of the steam siphon, steam vacuum, pulsometer, or centrifugal types are preferable. The ability of a pump to work without becoming clogged is of much greater consequence than a high efficiency in power consumption. When thoroughly dry quicksand may be readily excavated, al- though at times it becomes so hard as to require picking. Lumps 4 HANDBOOK OF EARTH EXCAVATION of apparently dry quicksand may be made " quick " by the agitation caused through handling or hauling, and become diffi- cult to remove from the wagons or cars in which they have been loaded. Sand is any material more finely divided than gravel and not a fine as clay. In general it consists of silica or quartz in very small fragments. The size, shape, and gradations of fine- ness of the particles have an influence on the characteristics of the mass. Shale is clay in process of changing to rock. It is usually soft and thinly stratified or laminated. Sub-soil is the soil below the top soil; generally the material too deep to be disturbed by ordinary plowing. It is not so finely divided as the top soil and does not contain as much organic matter. Top Soil is the upper layer of soil that is within reach of ordi- nary plowing. It is kept loose in texture by the growth and decay of plant roots. Wacke is a compact, dark colored clayey soil resulting from the decomposition of basaltic rock. Weight of Soils. Table I gives the weights of soils according to various authorities. TABLE I WEIGHT OF SOILS Clays Description Per cu. ft. Potters' clay, dry and solid, T 119 Potters' clay in lumps, T 63 Heavy clay, S 75 Half sand, half clay, S 96 Clay, M 63 Gravel Pit gravel, B Gravel mixed with clay, B 155 Trautwine says gravel weighs about the same as sand. Loam Common arable soil, S ' 80-90 Garden mould rich in vegetable matter, S 70 Arable soil, M 75.4 Old pasture soil, M 65.6 Land 100 years in grass, M 59.1 Common loam, perfectly dry, loose, T 72-S Common loam, perfectly dry, shaken, T 82-92 Common loam, moderately rammed, T 90-100 Mud Mud, dry, close, T 80-110 Mud, wet, moderately pressed, T 110-130 Peat Peat, dry, T 20-30 Peat soil, S 30-50 Humus ( decayed vegetable matter, H. ) 20.9 PROPERTIES OF EARTH 5 Sand Per cu. ft. Dry siliceous or calcareous sands, S 110 Quartz sand, M 90.3 Sand, perfectly dry, loose, T 90-106 Sand, perfectly dry, shaken, T 92-110 Sand, perfectly dry, rammed, T 100-120 Sand, sharp, very large and very small grains mixed, T... 117 Sand, voids full of water, T 118-120 Sand, dry, B 80-115 Shale Shale in place, T 162 Shale quarried, T 92 Authorities. T. Trautwine, B. Byrne, " Inspector's Pocket Book." M, Murray, " Soils and Manures." S, Shubler, " Hand- book of the U. S. Dept. of Agriculture," 1893. Effect of Depth on Weight. In " Soils and Manures," J. A. Murray gives the following table of results obtained from trials made at Rothamsted in England: Wt. per cu. ft. Wt. per cu. ft. Arable land Old pasture Top layer, 9 in. deep 89.4 71.3 Second layer, 9 to 18 in. deep 93.2 94.8 Third layer, 18 to 27 in. deep 98.4 100.2 Fourth layer, 27 to 36 in. deep 101.4 . 102.3 This is of considerable interest from the standpoint of exca- vation. If we consider these results as applied to the excavation of a 36-in. trench they show that in the arable land the second half of the trench weighs 9.4% more than the first; in the old pasture the increase is 21.9%. The increase in density is of course less at greater depths but it is a factor worth remem- bering. Specific Gravity. The specific gravity of the principal miner- als of which soils are composed is: Quartz 2.65 Feldspars 2.5-2.7 Calcareous minerals 2.7-3.0 Because of air spaces between the particles the apparent specific gravity of a cu. ft. of earth is less than that of the minerals of which it is composed. The range of apparent specific gravity for the soils in Table I is as follows: Clays 1.01-1.91 Gravel 1.96 Loam 0.95-1.44 Peat 0.32-0.48 Sand 1.45-1.85 Shale 2.60 See the author's " Handbook of Rock Excavation " for numerous data on specific gravity, voids, etc. 6 HANDBOOK OF EARTH EXCAVATION Voids in Dry Earth. A mass of spheres all the same size, packed as closely as possible has 26% voids or inter spaces; but packed as loosely as possible such a mass has 48% voids. A tumbler full of bird shot has 36% voids. Sand with rounded grains of nearly uniform size has 41% voids while crushed quartz sand of uniform size has 55% voids. It is evident that where large grains and small grains are mixed the percentage of voids of the mass is decreased, but it is not decreased to the 'extent that might be expected theoretically. Thus when 1 cu. ft. of coarse gravel having 40% voids is mixed with 0.4 cu. ft. of sand we do not get 1 cu. ft. of gravel and sand mixture as might be expected. In practice no mixture of clean sand and gravel reduces the voids to much less than 22%. It is generally safe to assume that pit sand or gravel has 35 ;o 40% voids when measured loose. Loose sand of uniform size having 45% voids and weighing 85 Ib. per cu. ft. can be com- pressed to 36% voids and 96 Ib. per cu. ft. by saturating with water and ramming. Gravel, however, will not shrink as much under the rammer. Pebbles of uniform size having 44% voids weighing 84 Ib. 'per cu. ft. can be rammed to a mass weighing 92 Ib. and having 39% voids. An artificial mixture of gravel and sand weighing 125 Ib. per cu. ft. loose and having 30% voids can be rammed until it has 20% voids and weighs 145 Ib. per cu. ft. Murray gives the following values: Per cent, voids Clay 59.5 Loam 53.4 Loam, old pasture 64.1 Quartz sand 44.7 Humus 75.0 Size of Particles. It is not known what the ultimate limit of division of earth may be, but particles of 0.0001 mm. have been measured. The chief difference between sand and clay is in the size of the particles; in addition to this, as the felspathic rocks are softer than quartz they are apt to become more finely divided so that clays are made up largely of this material. A thousand miles down a river from their origin the softer rocks will be ground into clay, while the quartz will still exist as fine sand. Further up the river sand composed of fine particles of the softer rocks could be found. Frost Penetration. The heat conductivity of a soil depends on its moisture, contents and compactness. Solid rocks conduct heat five times as fast as water, but when pulverized the con- tinuity of the material is broken by air spaces and the heat PROPERTIES OF EARTH 7 conductivity becomes less than that of water. Compacting and wetting a soil increases its ability to conduct heat, while loosen- ing and drying has the opposite effect. Engineering and Con- tracting, May 8, 1918, says that frost will penetrate to a greater depth in gravel than in clay when both are saturated with water, for water is a better heat conductor than the minerals that compose soils. In a New England town last winter frost pene- trated to a depth of GI/ ft. in gravel and only 3i ft. in clay. The following values are taken from a table appearing in Engineering and Contracting, June 27, 1917: Coefficients of Heat Conductivity ( B.T.U. per sq. ft. per hr. for each degree difference in temperature on the opposite side of a plate 1 in. thick.) Coefficient of heat Material conductivity Clay, tough, sundried 6.4 Clay, soft, very wet 9.0 Sand 2.48 Sand, white, dry 2.70 Sand, white, saturated with water 20.30 Soil, dry 0.97 Soil, wet 4.64 Engineering and Contracting, Dec. 11, 1918, quoting from a report of the Committee on Frozen Water Mains of the New England Water Works Association, gives the following informa- tion in frost conditions encountered during the winter of 1917-18 in various sections of the country. Forty-three cities reported that frost was noted at depths of G ft. or over. In 57 cities the average depth of frost penetration was 4 ft. or over, while 21 cities reported an average depth of 5 ft. or over. The greatest depth noted, 9 ft., was at Duluth and St. Paul, Minn. In the first city the penetration was in clay and rock soil; in the second it was in sand and gravel, i At St. Paul the average depth was 7.5 ft. Depths of 8 ft. were noted at Winnipeg, Man., in gravel soil and at St. John, N. B., in clay soil. Angle of Repose. The slope that the face of a mass of earth assumes when exposed to the elements for several months is called the natural slope. The angle of repose is the angle or slope that a face of earth makes with the horizontal when not sub- jected to the elements. The angle of repose of various earths as given by different authorities in Table II. TABLE II ANGLE OF REPOSE OF VARIOUS EARTHS Clay Well drained clay, M 45 or 1 -1 Wet clay, M 16 or 3 -1 HANDBOOK OF EARTH EXCAVATION Gravel Gravel, M ............. : ....................... 40 or 1*4-1 Shingle, Fl .................................... 39 or 1^4-1 Gravel exposed to waves, Fl ................. 11 or 5 -1 Loam Compact earth, M ............................ 50 or %-l Vegetable earth, M ........................... 28 or 2 -1 Sand Dry sand, M .................................. 38 or 1^4-1 Wet sand, M .................................. 22 or 2 l / 2 -l Dry sand, R .................................. 28-30 or 1%-1 Sand subjected to waves on shore of Lake Erie, G .................................... 5 or 10 -1 Stone Rubble, Fl .................................... 45 or 1 -1 Broken stone, E & C ........................ 38 28' or Authorities. M, Molesworth, Fa, Fanning, Fl, Flynn, ("Irri- gation Canals"), R, Rankine, G, Observation by the Author, E & C, Engineering and Contracting, May 30, 1906. Greatest Height of Vertical Bank. The following table is given by Austin T. Byrne ("Inspector's Pocket Book"). Greatest depth of temporary Earth vertical face Clean dry sand and gravel .............. to 1 ft. Moist sand and ordinary surface mold... 3 to 6 ft. Clay, ordinary ............................ 10 to 16 ft. Compact gravel ........................... 10 to 15 ft. Dry clay in place frequently stands at much steeper slopes than the angle of repose would indicate. C. S. Phelps in Eng. News, July 1, 1896, says that in South Carolina clay cut at % to 1 stands better than at iy 2 to 1, because the clay bakes in the sun and the steeper slopes shed water without saturating. In Engineering News, Sept. 13, 1900, H. C. Miller gives examples of 1 to 5 slopes in Brazil that have stood for years. Many rail- roads use a slope of y 2 to 1 for the sides of cuts in clay. Shrinkage. Earth always .swells when excavated. On being deposited in a fill or embankment it shrinks Obviously the amount of swell depends upon the compactness of the earth prior to excavation. The amount of shrinkage from the loose earth volume depends upon the means of compacting it, or upon the time a fill has stood, or both. Thus, if no means of compacting are employed, shrinkage may continue for years, whereas, after thorough compacting, there may be no subsequent shrinkage The earth may or may not shrink to its original volume, or it may shrink to less than the original volume. As compared to original volume, ultimate shrinkage depends not only on the means of compacting and the time, but upon the compactness of PROPERTIES OF EARTH f) the earth before it was excavated. Any earth, no matter how compact in its original position, will shrink into smaller volume if sufficient means of compacting are employed. Ordinary tabu- lated percentages of shrinkage are useless. There is so much variation between earthwork jobs that the information that clay shrinks 10% is entirely inadequate, unless accompanied by state- ments of where it was excavated and where and how deposited. The reader can best obtain data on shrinkage by having many examples set before him from which he can select those where conditions were nearest his own problem. Beginning with the results of observations by Elwood Morris, in 1841 (published in the Proc. Franklyn Inst.) , data given in the first edition of this book and other data from more recent Engineering literature follow. Railroad Embankment Built by Carts. Morris moved eartli by means of carts and wooden drag scrapers, obtaining the fol- lowing results: Excavation Embankment Shrinkage Material cu. yd. cu. yd. per cent. Yellow clayey soil 6,970 6,262 10.15 Yellow clayey soil 25.975 23,571 9.25 Light sandy soil 10,701 9,317 12.93 Total 43,646 39.150 10.3 Gravelly earth (small scale experiment) 12.0 The railroad embankments built by Morris were deposited in layers; one-horse carts and wooden drag scrapers being the means employed in moving the earth. Work was begun one year and finished the next, so that fills went through one winter before final measurement. Note that the shrinkage had all oc- curred during the progress of the work. Small Scale Experiments in India were made by Mr. J. H. E. Hart by digging trenches 2 ft. deep and 6 ft. wide, casting out the earth with shovels. Trench No. 1 in "black cotton soil" measured 416 cu. ft., and the loose earth cast out measured 600 cu. ft., showing a swelling of 184 cu. ft. or 23%, which was checked by immediately shoveling the earth back into the trench, without ramming it, when 101 cu. ft. of loose earth were left over after filling the trench level full. During the long and very wet rainy season which followed, the earth in the trench settled; and as fast as it did so the loose earth was shoveled in, until at the end of the rainy season only 221^ cu. ft. of loose earth remained, showing an increase of 5.3% over the original measure. Trench No. 2 in "gravelly soil" (2 ft. deep) showed a swelling of 25% when the earth was thrown out and measured loose in a 10 HANDBOOK OF EARTH EXCAVATION bank 1% ft. high; and, after settlement as before under heavy rains of one season, half the loose material remaining when the trench was first filled, was left, which was 12%% of the volume of the trench. In both these cases the earth had not been walked over or pounded when measured loose- Swelling of Newly Excavated Material. A. Von Kaven, Presi- dent of the Royal Polytechnic Institute in Aix-la-Chapelle, gives in his book on road building the following. According to a series of observations when material is first loosened it swells thus: Material Increase in volume Sand 15 to 20% Clay and sand 22% Hard clay, lia,s 24% Clay mixed with cobbles 2G%> Solid gravel bank 289^ Soft rock which can be picked 30% Hard rock 34 to 50% While Von Kaven does not state how the material was loosened and measured, in common with other European authorities he doubtless refers to materials loosened with a shovel and not packed down afterward by traffic, rain or otherwise. Swell of Material in Levees. Geo. J. Specht, in the Trans, of the Technical Society of the Pacific Coast, May 1, 1885, gives results of measurements made on levee work coming under his own observation. The levees were built in 1884 along the Feather and Sacramento Rivers in Sutter County, California. The levees were about 12 ft.' high, 6 ft. wide on top and 90 ft. wide at the base with front slope of 1 to 3 and rear slope of 1 to 4. Ma- terial was borrowed from both sides for a distance of 100 ft. from the toe of the slope, and buck scrapers drawn by four horses were used to move the earth which was not rolled. A buck scraper drifted or pushed to place about 90 cu. yd. per day. The soil was well plowed before the fill was placed upon it to insure a good bond. There are several noteworthy points of difference between this work and that of Morris already given. In the first place Sutter County, California, is a rainless district in the summer. Secondly the material was taken from the bed of a river and such ma- terial is always more dense than ordinary, due to the puddling action at times of high water. Thirdly no wheeled vehicles passed over the fill during construction, whereas a large quantity of loose earth was pushed into place with the long buck scrapers. These factors, I believe, combined to make an unusually favor- able condition for a swelling of earth when taken from cut to fill. I would especially emphasize the fact that sandy earth in PROPERTIES OF EARTH 11 the bottom of overflowed river valleys, and earth approaching hard pan in certain glacial deposits is very dense. Such earth is quite certain to occupy more space in fill than it did in cut, unless thoroughly rolled or rammed. The results obtained by Specht were: 9,398 cu. yd. in cut (h eavv adobe clay) made 9,470 cu. yd. fill, measured three weeks after finishing. 10,000 cu. yd. in cut (adobe in sandy loam) made 10,290 cu. yd. in fill. 29,000 cu. yd. in cut (adobe in sandy loam) made 30,330 cu. yd. in fill. 53,350 cu. yd. in cut (sandy loam, with small amount of adobe and hard pan) made 58,350 cu. yd. in fill, or about 9.4% increase. 202,034 cu. yd. in cut made 208',915 cu. yd. fill (.3 months' work ) . Shrinkage of Embankments. P. J. Flynn (Engineering News, May 1 and 8, 1880) collected a great array of data on earth swelling and shrinking; and reasoning erroneously by combining the shrinkage of the Morris embankments with the swelling of the Specht embankments, he reached the remarkable conclusion that a contractor should always be made to set his fill stakes 17% higher than the final fill was to be. His idea was that Specht had measured his fill immediately after completion, while Morris had waited until rains had settled it. This was erroneous reasoning. The following data on bank shrinkage after the bank has been finished, are taken from the letters of contributors to a contro- versy on this matter in Engineering News, Nov. 15, 1900, and subsequent issues. Authority C. H. Tutton TABLE III EARTH SHRINKAGE Conditions of fill ^ f t ..Pit gravel for railway fill by wagons 14 Pit gravel for failway fill by wagons 14 H. P. Gillette Gravelly dike, made by wheelers 15, Sandy loam Erie Canal bank 22 Gravelly road embankment by dump cars 16 Chas. R. Felton..Sand and gravel street fill by carts 5 and 6 1 .Same as above, by carts .. 7 10 12 16 18-20 Vertical shrinkage after 6 mo. l /2% after 12 mo. 3% after 4 yr. 3% after 50 yr. 3V 2 7c after 1 yr. to 1% after 4 yr. 2% after 4 yr. 1% after 4 yr. 2*4% after 4 yr. 1/2% after 4 yr. 2 r / f after 4 yr. after 4 yr. 12 HANDBOOK OF EARTH EXCAVATION Authority Conditions of fill Woolsey Finnel. .Railroad fills (actual levels), sand and gravel by wheel- ers . .Clay loam and earth, by wheelers " . .Calico clay, and kaoline by wheelers .Same as above, by carts ... .Earth, carts, wagons, cars.. .Same as above, by wheel barrows L. B. Merriam. .Railway fills, by scrapers .. by wheelers . by dump cars Depth of fill, ft. Vertical shrinkage W. F. Shunk... .Railway fills 1% after 6 mo. 2 to 3% after 6 mo. 5% after 6 mo. 8% after 6 mo. 4 to 10% after 6 mo. 15 to 25% after 6 mo. 3% 5% 7% 2 to 4% Shrinkage of Railway Embankment. Engineering and Con- tracting, March 19, 1919, gives the following: Specific instances of shrinkage of railway embankments were cited in a committee report submitted this week at the 20th annual convention of the American Railway Engineering Association. Information was given regarding 8 embankments between mileposts 540 and 553 on the Atchison, Topeka & Santa Fe Ry. The following tabula- tion compiled from the report shows the percentage of material required to restore the several embankments to their original width after a lapse of 4 years' time: Quantities in fill at completion, Nov., 1911 Cu. yd. Embankment No. 1 Embankment No. 2 Embankment No. 3 Embankment No. 4 Embankment No. 5 Embankment No. 6 Embankment No. 7 Embankment No. 8 15.762 147,582 125,680 19,067 150,852 57,709 33,902 62,207 Quantities re- quired to re- store fill to Amount of original width shrinkage of 18 ft.. Per cent. Nov., 1915 Cu. yd. 1,824 11.6 6,995 4.7 2,371 1.9 99 .5 664 .4 1,642 2.8 1,678 5.0 3,090 5.0 The base of embankment No. 1 was constructed from side borrow with fresnos. It was topped with wheelers and carts. The ma- terial was brown pack sand, gyp and joint clay. The base of embankment No. 2 was also made from side borrow with fresnos and wheelers. It was topped with cars. The material was the same as for No. 1. For No. 3 the base was placed with fresnos; it was topped with wheelers. The material was brown pack sand, gyp and joint clay. Several rains occurred during the period this fill was being placed which accounts for the small amount of shrinkage. The base of No. 4 was placed with fresnos; it was topped with wheelers using gyp and pack sand. The base PROPERTIES OF EARTH 13 of No. 5 was placed with fresnos from side borrow; it was topped with machine and wagons. The material was red sandy clay and gyp. Fresnos were used in placing the base of No. 6; it was topped with wheelers. The material was brown sandy clay and gyp. During the time this fill was being put in there were several very heavy rains, which accounts for small amount of shrinkage. The fill for embankment No. 7 was made from side borrow with fresnos; the material was black sandy loam and clay. The fill for No. 8 was made from side borrow, the base being placed with fresnos and the top with wheelers. The ma- terial was black sandy loam and brown sandy clay and gyp. Effect of Water on Clay Shrinkage. In the ninth annual re- port of the Boston Transit Commission, 1903, data on clay shrink- age are given by Howard A. Carson. Experiments were made on 12-in. cubes of clay taken from the East Boston Tunnel which were dried for three days beside a warm stove. Experiment No. 1, clay containing no sand, from East Boston Tunnel : No. 1 No. 2 No. 3 Shrinkage in volume 19.5% 19.3% 16.3% Shrinkage in weight 21.4% 22.2% 21.4% 1 cu. ft. shrank to 0.8 cu. ft. 1 lin. ft. shrank to 0.93 lin. ft. Experiment No. 2, clay containing 30% fine sand: Shrinkage in volume 11.5% Shrinkage in weight 18.6% 1 cu. ft. shrank to 0.9 cu. ft. 1 lin. ft. shrank to 0.96 ft. Carson states in a letter to the author that the first tests were made upon 12-in. cubes of clay spaded from the tunnel but that later tests were made on clay cylinders 2 in. in diameter by 4 in. long placed in gasoline. Measurements were made by the displacement of mercury and the results were as follows. Effect of water on volume of clay : Water, per cent. Volume of c,lay of dry weight per cent. 28 100 25 95 23 92 22 9iy 2 21 90 19 88 18 87 16 83 15 82 141/2 80 13 80 14 HANDBOOK OF EARTH EXCAVATION Plotted to scale these tests show that the volume varies almost exactly as the percentage of water. European Experience with the Shrinkage of Clay. An article by Tlianneur, Ing. Fonts et Chausses, is translated in Engineering Acws, April 2, 1887, by H. N. Ogden. In the embankments built in 1874-1882 from the quarry-clay and green loam of the Coulomnieer district an allowance of 10 to 15% was made as compared with the excavation. But in spite of this precaution these embankments settled. Capt. Martin, of the English engineers, showed in a paper, read Mar. 23, 1882, that for certain miry loams the shrinkage attained 23.5%. Preliminary tests can alone determine the coefficient for any particular case; but prudence will indicate 25% as a minimum allowance. This is borne out by experience in building the "new wall" at Calais. Here on the south front the ditch was dug in miry loam, and the difference in volume, between the excavation and material extracted, was so great as to be at first charged to error in calculation. Experiments have been made as follows: An excavation was made specially of 5,174 cu. yd., the earth removed was levelled and tamped on a heavy timber platform, and when measured was found to contain 4,912 cu. yd. This dirt, however, was artificially moistened to compensate for drying; and, as the water already in the soil could not be measured, it was impos- sible to arrive at relative quantities of moisture. As a certain portion of this water drained off from the "filling," it is rea- sonable to conclude that the first settling, to the extent of about 5%, is explained by this loss of moisture. In the experiment above noted a cube (0.45 cu. ft.) weighing 50 1')., was taken from the levelled and pounded and still fresh earth. This cube kept for some days at the normal temperature dried quite rapidly, and after one year was reduced to a volume of 0.39 cu. ft. and weight of 45.5 Ib. Shrinkage of Rolled Earth Dam. The most valuable careful tests made in recent years are those described by Burr Bassell in his book on "Earth Dams" (also in Engineering News, July 10, 1902). Tests were made on the material used in the construction of the Tabeau Dam which was a mixture of 62% earth and 38% gravel. Material in its natural bank weighed 11G.5 Ib. per cu. ft. Material sprinkled and rolled in G-in. layers in embankment weighed 133 Ib. per cu. ft. Material delivered by wagons moist and dumped loosely weighed 76.6 Ib. per cu. ft. PROPERTIES OF EARTH 15 Material dug out of dam embankment loose and shaken weighed 80 Ib. per cu. ft. The natural soil contained 19% of moisture, and 33% of water had to be added to fill all its voids, making a^otal of 52% of voids in the natural soil when loosened. From the foregoing it is evident that the natural bank when loosened and placed in a wagon swelled 46%, which is a high percentage and indicates an unusually dense bank. Upon roll- ing the earth in the embankment there was a shrinkage of about 12% from the original place measure. Let it be noted that the rolled fill weighed 1% times as much as the loose moist earth and that its weight of 133 Ib. per cu. ft. is almost as great as solid masonry! In fact, concrete often weighs no more than this earth dam embankment. For a description of the construc- tion of the Tabeau Dam see the chapter on Earth Dams. Shrinkage of Embankment of Hardpan and Boulders. The Forbes Hill Reservoir (Mass.) is described in Engineering \ews, Mar. 13, 1902. The embankments were made of clay hardpan con- taining boulders; a four-horse plow was required to loosen the hardpan. The following are the volumes of cut and fill: Hardpan, measured before loosening 17,466 cu. yd. Rolled hardpan embankment 15,474 ' Shrinkage, 11.4% or 1,992 " " Material excavated as above 17,460 cu. yd. Estimated equivalent amount of stone (bould- ers, etc.), removed, 5.9% or 1,013 cu. yd. While the item of stone removed is rather obscurely recorded it would seem that the natural bank really shrank 1,992 1,043 = 849 cu. yd. or less than 5% during the rolling. After the fill was finished it did not shrink at all during the winter following. Shrinkage of Top Soil Under Rolling. The shrinkage of top soil rolled in 0-in. layers has been investigated in the construc- tion of the North Dike of the Wachusett Reservoir, near Clinton, Mass., and is reported upon by Alex. E. Kastl, " The Technic " for 1902, Eng. Xews, Aug. 7, 1902. The length of the trench which was filled was 1,375 ft. About 500 ft. of this length was about 30 ft. deep, 30 ft. wide at the bottom, with- side slope of 1 on 1. The remainder varied in depth from to 25 ft., and in width from 50 to 80 ft. between slope stakes ; with side slopes of approximately 1 to 1, having been partially filled under a previous contract. The soil was excavated from an area of 64 acres to an average depth of 0.78 ft. About 59 acres of this area contained stumps. The land from which the soil was excavated was called sprout land land which has been cleared of forest growth and again allowed to grow over with trees and brush. The volume 16 HANDBOOK OF EARTH EXCAVATION of the soil measured in excavation was 80,355 cu. yd. The vol- ume of the soil after it w.as deposited and compacted in the cut- off trench was 50,735 cu. yd. or 29,020 cu. yd. less than the vol- ume measured in excavation. The final levels were taken a few days after the completion of the work. From the above it follows that the shrinkage of the soil was 37%, calling the volume of 80,355 cu. yd. 100%. This shrinkage includes roots y 2 in. or more in diameter and stumps so far as they were originallv embedded in the soil, but which were removed and burnt. Roots y 2 ' n - or more in diameter, stumps or other wood were not allowed to be deposited with the soil in the cut-off trench. The soil was free from stones. The volume of the soil excavated was determined from levels taken when there was no frost in the ground. The first levels were taken after the ground was cleared of trees and brush, which were removed and burnt or otherwise disposed of, and before the contractor had commenced grubbing; and the final levels after the final excavation was finished. The volume of the soil excavation includes the roots and stumps so far as the same were embedded in the layer of soil excavated. The levels extended over the entire area stripped and were taken not more than 25 ft. apart, that is, not less than 70 cuts or depths of soil were de- termined for each acre. The ground was divided into squares 500 ft. on a side, the corners of which were permanently marked and the sides were used as base lines for the cross section work. The average depth given, 0.78 ft.,, is the total volume of the soil excavated divided by the area, and is only intended to give some idea of the depth of the soil stripping. All the soil con- taining 4% or more of organic matter is removed from the reser- voir site. The volume of the soil when in the trench was cal- culated from accurate cross-sections, taken not more than 25 ft. apart before and after the filling of the trench. Before rolling the soil it was watered as much as it would bear without stick- ing to the roller. The type of roller which was used weighs about 6,000 lb., and is drawn by two horses. The cylinder of the roller is 5 ft. long and is composed of 19 cast-iron wheels, 3 in. thick at rim, 10 being 2 ft. 11 in. and 9 2 ft. 8 in. in diameter, respectively, arranged alternately. The amount of shrinkage encountered on this work, 37%, is ex- treme, but was to be expected as forest top soil is the loosest of all soils; and rolling in thin wetted layers is a very efficient way of compacting. Shrinkage of Embankment of Wachusett Reservoir. Accord- ing to Engineering ~Kews, June 11, 1903, the North Dike of the Wachusett Reservoir was flooded after rolling, from May 19 to June 30. Small dikes were used to hold the water on an area of PROPERTIES OF EARTH 17 4} acres on the main dike which had been built up of 6-in. rolled layers to a height of 51 ft. Settlement after Hooding ranged from 0.06 ft. to 0.26 ft., the average being 0.15 ft. On a dike 40 ft. high built in 7.5-ft. layers without rolling the maximum settlement was 1 ft. and the average 0.47 ft. Shrinkage of Rolled Embankment. In the construction of the Peterborough. Ont., lock on the Trent Canal the earth embank- ment, upon which the canal is carried up to the back of the breast wall, was built in layers about 8 in. in thickness, thor*- oughly compacted and rolled. During the hot and dry season the earth filling was liberally watered. The material was clay con- taining small stories. This method produced an embankment hav- ing the remarkable record for settlement of only about 0.1 ft. in a period of nearly a year where the depth of fill was upwards of 40 ft. Increase in Volume of Dredged Material. In the construction of the Buffalo Breakwater, which is described by Emile Low in " Trans. Am. Soc. C. E.," Vol. 52, the total quantity of material dredged was as follows: Cu. yd. Season of 1897 by dipper dredge 8,117 " 1898 4,934 " 1898 by clam-shell dredge 193,810 Total scow measurement 206,861 Total place measurement 192,258 Swelling 17.6%, or 14,603 The following results have been found on the United States Public Works: Increase of scow measurement over place Material measurement Rock (large fragments make greater increase).. 75 to 100% Sandstone and limestone 307o Very soft mud 13% Soft blue mud 15% Hard sand with small admix.uie of silt 20-30% Loose muck dredged from reservoir 15-17% With the hydraulic suction dredge where nauch fine light material is encountered the scow measure will be equal to or less than the place measure. Summary. From this varied mass of data we may deduce the following general rules: 1. Taking extreme cases, earth swells when first loosened with a shovel, so that after loosening it occupies 1^ to 1^ times as 18 HANDBOOK OF EARTH EXCAVATION much space as it did before loosening; in other words loose earth is 14 to 50% more bulky than natural bank earth. 2. As an average we may say that clean sand and gravel swell 14% ; loam, and loamy sand and gravel, 20% ; dense clay and dense mixtures of gravel and clay, 33 to 50%. 3. That this loose earth is compacted by several means: (a) the puddling action of water, (b) the pounding of hoofs and wheels, (c) the jarring and compressive action of rolling arti- ficially. 4. If the puddling action of rains is the only factor, a loose mass of earth will shrink slowly back to about its original volume; but an embankment of loose earth will at the end of a year be still about 8% greater than the cut from which it came. 5. If the embankment is made with small one-horse carts, or wheel scrapers, at the end of the work it will occupy 5 to 10% less space than the cut from which the earth was taken; and in subsequent years will shrink about 2% more, often less than 2%. 6. If the embankment is made with wagons or dump cars, and made rapidly in dry weather without water, it will settle verti- cally, 3 to 10% in the year following the completion of the work and very little in subsequent years. 7. The height of the embankment appears to have little effect on the percentage of its subsequent shrinkage. 8. By proper mixing of clay or loam and gravel, followed by sprinkling or rolling in thin layers, a bank can be made weighing 1% times as much as loose earth, or 133 Ib. per cu. ft. 9. The bottom lands of certain river valleys and banks of ce- mented gravel or hardpan are more than ordinarily dense and will occupy more space in fill than in cut, unless rolled. Dry clay taken from deep cuts will absorb and hold additional moisture in embankment and will be accordingly increased in volume. 10. Dry, tough clay often breaks into chunks resembling shale, and then swells when first loosened almost as much as rock. Bibliography. " A Treatise on Rocks, Rock Weathering and Soils," George P. Merrill. " Soils and Manures," J. Allen Mur- ray. " Practical Designing of Retaining Walls," Win. Cain (co- hesion and friction). " Bulletin No. 64," Bureau of Soils, U. S. Dept. of Agriculture, 1900. CHAPTER II MEASUREMENT, CLASSIFICATION AND COST ESTIMATING Earthwork Definitions. The American Railway Engineering and Maintenance of Way Association have standardized defini- tions which are given in their "Manual" for 1915 as follows: Group A General. CLASSIFICATION. Arranging the material in groups according to its character. CONTRACT. A written agreement between two or more parties specifying terms, conditions, etc., under which certain obli- gations must be performed. (Specifications are a part of the contract.) ESTIMATE (noun). (a) A statement of work performed or ma- terial furnished, according to which payment is to be ren- dered. ESTIMATE (noun). (b) A statement showing the probable cost of a proposed piece of work. ESTIMATE (verb). The act of making an estimate. QUANTITIES. The amount of material to be handled, expressed in the usual units. SLIDE. The movement of a part of the earth under the force of gravity. !! . SPECIFICATION. That part of the contract describing the ma- terials for or the details of construction. STOCK-PASS. A culvert or bridge opening under the track, pri- marily for tbe passage of stock. UNIT PRICK. The price per unit of the various quantities speci- fied in a contract for which a certain work is to be per- formed. WAsiiorT. The carrying off of the permanent way by the im- pact and erosion of waters. Group K Itight-of-Way. KIGIIT-OF-WAY. The land or water rights necessary for the road- bed and its accessories. ROADIJED. The finished surface of the roadway upon which the track and ballast rest. ROADWAY. That part of the right-of-way of ' a railway prepared to receive the track. (During construction the roadway is often referred to as the "grade.") STATION GROUNDS. Property to be used for station purposes. Group C Technical. ALINEMENT. The horizontal location of a railway with reference to curves and tangents. 19 20 HANDBOOK OF EARTH EXCAVATION CENTER-LINE. A line indicating the center of an excavation, embankment or track. CONSTRUCTION STATION. The center line stake set at the end of each full 100-ft. tape or chain length (commonly called a "station "). CONTOUR. The line of intersection between a horizontal plane and a given surface. CROSS-SECTION. A section through a body perpendicular to its axis. CENTER STAKES. Stakes indicating the center line. ELEVATION OR HEIGHT. The distance of any given point above or below an established plane or datum. FINISHING STAKES. Final stakes set for the completion of the work. GRADE (verb). To prepare the ground for the reception of the ballast and track. GRADE-LINE. The line on the profile representing the tops of embankments and bottoms of cuttings ready to receive the ballast. GRADIENT. The rate of inclination of the grade-line from the horizontal. LOCATION. The center line and grade line of a railway estab- lished, preparatory to its future construction. PLAN. A drawing furnished for guidance of work. PROFILE. The intersection of a longitudinal vertical plane with the ground and established gradients; or a drawing repre- senting the same. SLOPE. The inclined face of a cutting or embankment. SLOPE STAKES. Stakes .set to indicate the top or bottom of a slope. SUBGRADE. The tops of embankments and bottoms of cuttings ready to receive the ballast. TOP OF SLOPE. The intersection of a slope with th ground sur- face in cuts, and the plane of roadbed on embankment. TOE OF SLOPE. The intersection of a slope with the ground sur- face in embankments, and the plane of roadbed in cuts. Group D Clearing. BRUSH. Trees less than 4-in. stump-top diameter, shrubs or branches of trees that have been cut off. CLEARING. Removing natural and artificial perishable obstruc- tions to grading. GRUBBING. Removing the stumps and roots. Group D Drainage. BOG.-^- Soft, spongy ground, usually wet and composed of more or less vegetable matter. MEASUREMENT, CLASSIFICATION AND ESTIMATING 21 CHANNEL. The depression or cut in which a stream is confined. CULVERT. An arched, circular or flat covered opening of timber, iron, brick or masonry, carried under the ro'adbed for the passage of water, or for other purposes. DRAIN. An artificial waterway for conducting water from the roadway. DRAINAGE. The interception and removal of water from, upon or under the roadway. . DITCH. An open artificial waterway for providing drainage. INTERCEPTING DITCH. An open artificial waterway for prevent- ing surface water from flowing over the slopes of a cut or against the foot of an embankment. SUBDRAIN. A covered drain, below the roadbed or ground sur- face, receiving the water along its length by absorption or through the joints. TRENCH. A narrow, shallow excavation to receive a structure. WATERWAY. A channel, either natural or artificial, for conduct- ing the flow of water. Group F Grading. AVERAGE HAUL. The mean distance material is to be hauled. AVERAGE TOTAL HAUL. The average total distance material is to be hauled. BENCHED. Formed into a series of benches. BERME. (a) The space left between the top or toe of slope and excavation made for intercepting ditches or borrow pits, (b) An approximately horizontal space introduced in a slope. BORROW (verb). To take- material from a borrow pit. BORROW ( noun ) . Material removed from a borrow pit. BORROW PIT. An excavation made for the purpose of obtaining material. EMBANKMENT (or Fill). A bank of earth, rock or other ma- terial constructed above the natural ground surface. EXCAVATION (or Cutting). (a) The cutting down of the natural ground surface; (b) The material taken from cuttings, bor- row pits or foundation pits; (c) The space formed by remov- ing material. FOUNDATION PIT. An excavation made for laying the foundation of a structure. HAUL. The distance material is moved in the construction of the roadway. FREE HAUL. The distance within which material is moved with- out extra compensation. OVERHAUL. The number of cu. yd. moved through the over- haul distance multiplied by the overhaul distance in units of 100 ft. 22 HANDBOOK OF EARTH EXCAVATION OVERHAUL, DISTANCE. The distance beyond the free-haul limit that material is hauled in constructing the roadway, for which extra compensation is allowed. RAMP. An inclined approach. SHRINKAGE. The contraction of material. STEPPED. Formed into a series of steps. TAMPED (or Packed). Packed down by light blows. TOTAL HAUL. The total distance that material is to be hauled. WASTE. Material from excavation not used in the formation of the roadway. WASTE OR SPOIL BANKS. Banks outside the roadway formed by waste. Group G Tunnels. CURB. A broad, flat ring of wood, iron or masonry, placed under the bottom of a shaft to prevent unequal settlement, or built into the walls at intervals for the same purpose. ROCK. A solid mass of mineral substance. SHAFT. A pit or well sunk from the ground surface above into a tunnel for the purpose of furnishing ventilation or for fa- cilitating the work by increasing the number of points from which it may be carried on. TUNNEL. An excavated passageway under ground or water. WELL (or Sump). A cistern or w r ell into which water may be conducted by ditches to drain other portions of a piece of work. Measurement. Earthwork is measured and paid for by the cubic yard or cubic meter. Usually the measurement is of earth " in place," that is in the natural -bank, cut or pit, before loosen- ing. This is called " place measurement." Where small embank- ments are built from side borrow or from other irregular pits, it is more convenient to measure the material in the embankment, and there is no reason why this should not be done. Levees and dikes are usually paid for by the cubic yard of compact embank- ment, the allowance required for shrinkage being given in the specifications and stated to apply to the slopes as well as the top of the dike. Structures built by hydraulic fill are measured in embankment. Dredging is often paid for by measurement in scows. Measurement " in place " is most satisfactory and should ordi- narily be adhered to for all " useful excavation," that is, where material is cleared away from -required space to make room for a building, railway, canal or other structure. Excavation done to procure material for building embankments is called " borrow." This, too, should be measured in place if the borrow pits can be MEASUREMENT, CLASSIFICATION AND ESTIMATING 23 readily cross-sectioned and if the means of transportation are such that none of the material is lost; otherwise it is best measured in embankment. But in any case the specifications should say how measurement is to be made; and if in embank- ment, they should say how soon after completion the embankment is to be measured and what, if any, allowance is to be made for shrinkage. On railway and other similar work " useful excavation " from cuts is used to build nearby embankments. This material is not paid for twice, but it is specified that it shall be hauled a cer- tain minimum distance, called " free haul," without extra com- pensation. Transportation beyond this distance, called " over- haul," is paid for in cents per cu. yd. per 100 ft. of overhaul. When the distance from cut to fill becomes so great that the cost of overhaul is greater than the cost of excavation, material from the cut is wasted, and a borrow pit is opened to obtain material for the embankment. In this case double payment is made, one for the yardage borrowed, and one for the yardage wasted. Legality of Methods of Calculating Earthwork. It is not the author's intention to discuss methods of staking out, measuring and calculating volumes in this book. These operations are classed as surveying, and information concerning them is readily available in books on that subject. One point however in which some of the text books are misleading is that they lay undue emphasis on the value of the prismoidal formula. The method of computing by average end areas is equally accurate if intelligently used, is much simpler, and has the sanction of the courts. The laws of some states provide that " in the absence of any specified agreement as to measurement," the " average end-area " formula must be used. Search No. 774 in the library of the American Society of Civil Engineers gives references on the law of New York State in re- gard to the calculation of earthwork. In a law suit over a contract for railroad building in South Dakota the court favored the prismoidal formula over the aver- age end-area method of computation. That this decision was brought about by the misuse of the average end-area method is shown by the following, which is taken from. a history of the case by Francis C. Tucker in Jour. Asso. Eng. Soc., Vol. 15, 1895. Another reason for large differences in quantities was that the engineers of the Railroad Company substantially gave the true prismoidal quantities, while the quantities given by the sub-con- tractor's engineer were obtained by averaging end areas without correcting in any way for the most extreme differences in con- secutive cross-sections, although he took his cross-sections much 24 HANDBOOK OP EARTH EXCAVATION further apart, usually, than the Company's engineers did, thereby much increasing the need of correction. He carried the method of averaging end areas to the extreme of using it at both ends of every cut on side-hill; that is, he invariably treated material which was actually pyramidal in form as being wedge-shape, thereby increasing the quantity by 50%. An attempt was made in the evidence to show that custom had established the method of averaging end areas without correction ; in effect, legalizing it. To disprove this the defendants introduced in evidence the fol- lowing portions of standard works: Computation from Diagrams of Railway Earthwork, Wellington. Preface, page 4. " Economic Theory of Location of Railways, Wellington." Page 896, articles 1257 and 1258. "Field Engineering," Searles. Page 203, article 235; page 225, article 254; page 229, article 256; page 236, article 263; page 200, article 231; page 201, article 232. il Excavations and Embankments," Trautwine. "Engineer's Pocket-Book," twenty-fifth thousand; page 161, Trautwine. " Mensuration of Volumes." Page 129, Davies' Legendre. They also claimed a strict interpretation of the contract, which says : " Payment being made only for number of yards actually removed by contractor, within the specified slope, grade and sur- face planes." and " Earthwork will be computed from cross-sec- tion notes of excavation prisms; that is, the quantities between the slope, grade and surface planes shall be taken, and shall be paid for by the cubic yard of twenty-seven (27) cubic feet." To show the importance of this question of methods, and the extortion that an unscrupulous engineer might perpetrate by a judicious misuse of the averaging end-area method without cor- rection, several test cases were selected from the cross-sections as measured and used by the sub-contractor's engineer, models , were made and put in evidence, and the differences between the two methods of computation amply testified to. , In one instance that engineer added, according to his own measurements, in a prismoid only 32 ft. long, 439 cu. yd. of excess, and this in solid rock. The following from "Wellington's Economic Theory of Railway Location," correctly and concisely states the proper use of the two methods of calculating volumes: " The nature of the error in the method of computing by aver- age end areas is this: The error increases as the square of the difference in center height, and is not in the least affected by the absolute volume of the solid. The heavier the work, therefore, or the less the sudden changes of profile, the less the proportion- ate error. That cut is an unusual one in which the error is more MEASUREMENT, CLASSIFICATION AND ESTIMATING 25 than 5 per cent, and that section of road would be very unusual on which the error was more than 1 per cent, and this error is always in excess. There are indeed certain possible solids in which the error will be In deficiency and certain others (those whose width on top is the same while the center heights differ, or vice versa) in which the end-area method is precisely correct, while certain methods by the prismoidal formula which appear much more exact will give a deficiency; but except on perhaps one solid in a thousand averaging end areas always gives an ex- cess of volume. " All methods of computing volume by first transforming the end sections into equivalent level-sections introduces a constant tendency to deficiency, and for that and other reasons are worse than useless labor, far simpler methods giving a more accurate result. The proper method of computing earthwork in con- struction is to compute by end areas only, and then at any later time when convenience serves to determine prismoidal corrections for those solids which need it only, which are those differing by more than two or three ft. in center height." In Engineering News, Dec. 13, 1002, I deduced a simple correc- tion formula for calculating earthwork by which the " mean end- areas formula " results can be corrected with ease and rapidity. I also derived the following rule for accurate use of the mean end-areas formula : Take cross-sections so close together that no cut or fill shall exceed by more than 50% the corresponding cut or fill in the previous cross-section; except that where the previous fill is the next cut or fill must be 2 ft. or less. Classification of Excavation. There is no scientific distinction between earth and rock, the line of demarcation being entirely arbitrary. Various classifications have been used on different works, but none yet devised is entirely satisfactory, and no phase of earthwork is so fruitful of disputes with contractors as this. The old test for earthwork, now generally discredited, was that material which could be plowed by a four-horse or a six-horse team should be classed as earth, and all other material as rock. This test had many limitations and disadvantages. Much material exists that cannot be plowed, yet is not called rock. Plows can- not be used at all on the rough surfaces of steam shovel cuts, and the test is utterly useless on frozen ground. It has been suggested that a better test would be to classify as rock all material in which holes for blasting must be drilled; material in which holes for blasting can be made by driving a bar 26 HANDBOOK OF EARTH EXCAVATION at a specified rate per minute, would then be classed hardpan; and material in which a bar can be driven at faster than the specified rate, as average earth. A better way out of the difficulty is to avoid verbal classifica- tion entirely, marking on the profile what the materials are in each cut, and specifying that payment will be made for materials, as classified on the profile, and not otherwise. This, of course, involves thorough exploration of the ground during the survey; but such an exploration should usually be made in any case. Specifications for the Classification of Excavation were sug- gested by James H. Bacon in a paper before the American So- ciety of Engineering Contractors, Jan., 1910. The following is taken from an abstract of his paper appearing in Engineering and Contracting, Feb. 23, 1910: There should be only three classes of excavated material, not including excavation under water, or excavation or removal of any artificial work such as old masonry, etc. These three classes should be: (1) Solid rock. (2) Loose rock. (3) Common ex- cavation. Common Excavation. In many specifications the dividing line between common excavation and loose rock is determined by the "plow test"; this test should be discarded entirely as unsatis- factory. There are thousands of acres, which may in the future be crossed by railways, where the material to be moved has not the faintest resemblance to rock and where no sane man would attempt to break ground with a plow. The plow test is impos- sible, and the logical result, if the specifications provide this test, is that such material must be classed as loose rock. Many of the western roads have discarded this test and specify that " all material not classed as loose or solid rock shall be common excavation." The companies using this specification spe- cify that loose rock shall be any rock that can be removed without blasting, although blasting may occasionally be resorted to, or any rock in detached masses varying in size between given limits, and that solid rock shall be rock in masses that cannot be re- moved without blasting. It will be noticed that these specifica- tions require a definition of the word " rock." Mr. Bacon submits the following specifications for excavated material : In these specifications the word " rock " shall be interpreted to mean any portion of the consolidated material forming the crust of the earth which has a greater volume than 1 cu. ft. Un con soli da ted materials, such as sand, gravel, clay, hardpan, are not rock under these specifications. Solid Rock. All rock in masses that cannot be removed without MEASUREMENT, CLASSIFICATION AND ESTIMATING 27 drilling and blasting. All boulders or detached pieces of rock that measure 1 cu. yd. or more in volume. Loose Rock. All rock which is loose or soft enough to be re- moved without blasting, although blasting may, at the option of the contractor, be occasionally resorted to. Detached pieces of rock measuring in volume from 1 cu. ft. to 1 cu. yd. Common Excavation. All material not solid or loose rock. The sizes specified for boulders and detached pieces are of course subject to be changed according to varying circumstances.' No tests are recommended, as the writer believes that they would serve no useful purpose and tend to cause complications. Excavation Under Water. This classification should be applied to all channels and pits under water which cannot be drained by ditching. The price or prices paid should be per cubic yard and should cover all material and labor, including coffer dams, neces- sary to do the excavation required. There should be at least two classes i.e., with and without coffer dams. In many cases special specifications would be necessary. Overhaul. Overhaul should be paid for, a price fixed by the company, per cu. yd. per hundred feet beyond the free haul, and the method by which overhaul is to be calculated should be described. The price should equal the cost of the work and is therefore a variable quantity. The limit of free haul is also vari- able. Both price and free haul limit should be accurately fixed for each section. A Cassification According to Difficulty of Picking. Wm. O. Lichtner, in Engineering and Contracting, Sept. 17, 1913, outlines a system of classification that has been used with success in tak- ing time studies on sewer work. Many varying materials were encountered on this work rang- ing from fine dry quicksand, through stiff clay to solid rock. Attempts to classify and study these materials according to or- dinary methods were unsuccessful although made with very great care. It was found that considerable difference existed from day to day in the cost of excavating what appeared to be the same material. A new set of time studies were made, adopting a new classifi- cation based on two variables, first, on the time it takes to pick the material, and secondly on the time it takes to shovel the material after it is picked. The material to be excavated then would be designated by two capital letters like BA. The first letter always designated the picking element and the second let- ter the shoveling element. By time studies the amount of time it would take a man to pick one cu. ft. of material was deter- mined and classified as B picking; also a time per cu. ft. was 28 HANDBOOK OF EARTH EXCAVATION determined for C picking, etc. In a similar manner, time per cu. ft. was determined for all kinds of shoveling. The pick- ing classification, which was always the first letter and always made with a capital, was as follows: A No picking required. B Loosens uniformly into fine material, with no appreciable lumps, and picks easily. C' Loosens easily into its component parts like a non- homogeneous material, as gravel mixed with sand, clay, or loam. Gravel less than 50% and not large. D Same as B except pick does not enter readily. E Loosens into lumps like a homogeneous material, not as hard as J. F Loosens hard into component parts like a non-homogeneous material as a cemented gravel. G Loosens into lumps and picks hard like a homogeneous ma- terial which is brittle. H Loosens into lumps. Material very tenacious. I Loosens into large lumps with very little fine. J Loosens hard on account of pick striking stones. K Loosening small boulders in trench (1 man size). L Loosening large boulders in trench. M Sledging rock. The shoveling classif.cation, which was always the second let- ter and always made with a capital, was as follows: A Finely divided material which heaps up on shovel. B Finely divided material which does not heap up on shovel. C Lumpy and fine material mixed. D Loose material like sand, clay, or loam, mixed with small gravel. E Same as D except large gravel. F Finely divided material. Can be spaded easily and re- quires no picking. G Supersaturated clay which can be shoveled. H Supersaturated clay which must be baled out in buckets. I Supersaturated material with small boulders which is baled out in buckets. J Sticky material which adheres to shovel. K Large lumpy material which averages 1 to 2 lumps per shovel. L Lifting small boulders from trench (1 man size). M Lifting large boulders from trench. This classification has been used with great success for some time now and is a most satisfactory classification for practical MEASUREMENT, CLASSIFICATION AND ESTIMATING 29 purposes. The determination of the time for each one of these items is a matter of time study which can be readily accom- plished. Studies will have to be made, of course, to take care of the great number of variables, and tables compiled accord- ingly- Railway Specifications of Classification. W. F. Dennis pre- sented a paper in Trans. Am. Soc. C. E., June, 1907. An abstract of this paper appears in Engineering and Contracting, Jan. 30, Feb. 6, and April 10, 1907. Mr. Dennis says in part: Nearly all railroads find it useful to retain classification in their forms of agreement. Such classification gives a solid rock material at one end and an earthy material at the other, with generally an intermediate material called loose rock, and fre- quently an additional hardpan classification, formerly more com- mon than now. While classification, in the opinion of some roads, leads to law suits, the writer believes that it saves money by reducing the contractor's risk, a matter that could be accomplished otherwise only by investigations, not always practical. Is it practicable to make a test upon the materials generally found in excavation for public work? As a first criterion, a simple, measurable test, easily applicable, and defining what should be properly in the " earth " classification, is whether or not the material can be plowed in its natural state by a definite plow pulled by a definite number and weight of stock. Whether this material is moved by scraper, grader, cart, car, wheelbarrow, or steam shovel, what is meant is clearly described, namely a ma- terial which a designated plow will produce in shoveling condi- tion. This description excludes from the earth classification some material included in some earth specifications, and includes some material which, in others, is classed as loose rock or as hardpan. As will be seen later, earthy material, not included in the " earth " classiiication, goes to an intermediate classification, for convenience and other considerations, termed " loose rock." The reason for placing the earthy material, sometimes included in earth and hardpan classifications, in the loose-rock classifica- tion, is the obvious one of similarity of v oost. If the material is too wet to be plowed, as in case of swamp muck, quicksands and some gumbos; or is too hard to be plowed, like hardpan, ce- mented gravel, etc., holding to the proper theory of grouping by rough similarity in cost, no designation by name can properly make it "earth" (in a cost sense) for all appliances, although it might be for some. Additional costly work may be required to get the material loaded or transported. In some cases the cost of unplowable earthy material may approximate and exceed 30 HANDBOOK OF EARTH EXCAVATION that of solid rock; but, speaking generally, the cost is somewhat similar to the cost of loose rock, and such material is most fairly included in that classification. Preliminary to the consideration of a physical test for solid and loose rock, the following definitions have been abstracted from current specifications: Solid Rock New York, New Haven and Hartford. " All rock or stone con- taining one cubic yard or more." (All other material is earth. ) Erie. " Rock in masses exceeding one cubic yard, which cannot be removed without blasting." Pennsylvania. " Rock in masses exceeding one cubic yard, which cannot be removed without blasting." Baltimore and Ohio. " Rock in solid beds or masses, which may be best removed by blasting." Chesapeake and Ohio. " Rock in ledges and detached masses ex- ceeding one-half cubic yard, which may best be removed by blasting." Norfolk and Western. " Rock in masses which may best be re- moved by blasting." Southern. " Rock in masses of more than one cubic yard, which may be best removed by blasting." " Big Four." " Stone in solid masses or ledges." Chicago, Burlington and Quincy. " Stratified rock weighing more than 140 Ib. per cubic foot, which can only be removed by blasting." Chicago and Alton. " All stratified rock and rock occurring in masses which can only be removed by blasting . . . must ring under hammer." Great Northern. " Rock in place, in removing which it is neces- sary to resort to drilling and blasting." Atchison, Topeka and Santa Fe. " Rock in solid beds or masses in its original or stratified position . . . other material which can be removed without continuous drilling and blasting, but which is as difficult ... as solid lime or sandstone." Illinois Central. " Rock in solid beds or masses in its original position . . . which may best be removed by blasting." (Everything else classed as "common excavation.") Northern Pacific. " All rock in masses that cannot be removed without drilling and blasting." Missouri Pacific. " Rock in solid beds or masses, in its original position, which can only be removed by continuous Wasting." MEASUREMENT, CLASSIFICATION AND ESTIMATING 31 What is " rock " and " stone " ? Notice the following defini- tions: Standard Dictionary. Rock. " The consolidated material form- ing the crust of the earth. . . not excluding beds of clay or sand ... a rock may consist of one mineral species, as lime- stone, or of several intermingled, as granite . . . massive rock, a rock that does not exhibit foliation or schistose struc- ture." Stone. " A small piece of rock. Rock as a material, a piece of rock shaped for a specific purpose. Synonyms, boul- ders, cobble, mineral, gem, pebble." Century Dictionary. Rock. " The mass of mineral matter of which the earth, so far as accessible to observation, is made up; a mass, fragment or piece of the crust, if too large to be designated as a stone. The unconsolidated stony materials which form a considerable part of the superficial crust, such as sand, gravel and clay, are not commonly designated as rock or rocks; the geologist . . . includes under the term rock ... all of the consolidated materials forming the crust, as well as the fragmental or detrital beds which have been derived from it." Stone. " A piece of rock. The name rock is given to the aggregation of mineral matter of which the earth's crust is made up. A small piece or fragment of this rock is generally called a stone." Webster's Dictionary. Rock.-" Any natural deposit forming part of the earth's crust, whether consolidated or not." Stone. " Concreted, earthy or mineral matter . . . also any particular mass of such matter. In popular language, very large masses of stone are called rocks; small masses are called stones; and finer kinds, gravel or sand." Gillette's " Rock Excavation." " Rocks are aggregates of one or more minerals, or the disintegrated products of minerals." These definitions do not help to clear up any uncertainties there may be in railroad classifications. Loose Rock t ?,/.- ifrjf'tfrf* -"-jo .-.:;.; i:'...fUt>> r> ' . n-t.-hvVifc m^i- Erie. " Slate, shale or other rock which can properly be removed by steam shovel, pick or bar, without blasting, although blast- ing may be resorted to on favorable occasions to facilitate the work . . . detached masses, 3 cu. ft. to 1 cu. yd." Pennsylvania. " Stone and detached rock lying in separate and continuous masses containing not over one cubic yard; also 32 HANDBOOK OF EARTH EXCAVATION all slate or other rock that can be quarried without blasting, although blasting may be occasionally resorted to." Baltimore and Ohio. " Slate, coal, shale, soft friable sandstone and soapstone, detached masses 3 cu. ft. to 1 cu. yd." Chesapeake and Ohio. " Shale, slate, ochre, which can be removed with pick and bar, and is soft and loose enough to be re- moved without blasting, although blasting may be occasion- ally resorted to. Detached masses 3 cu. ft. to 1 cu. yd." Southern. " Soapstone, shale and other rock which can be re- moved by pick and bar and is soft and loose enough to be removed without blasting, although blasting may be occa- sionally resorted to. Detachtd stone 1 cu. ft. to 1 cu. yd." Norfolk and Western. " Shale, soapstone, and other rock which can be removed by pick and bar, and is soft and loose enough to be removed without blasting, although blasting may be .oc- casionally resorted to. Detached masses 1 cu. ft. to 1 cu. yd." " Big Four." " Shale, coal, slate, soft sandstone, soapstone, con- glomerate stratified limestone in layers less than 6 in. de- tached masses 3 cu. ft. to 1 cu. yd." Chicago, Burlington and Quincy. " Stratified rock which can be removed by pick and bar weighing more than 140 Ib. per cu. ft. Detached masses 3 cu. ft. to 1 cu. yd." Chicago and Alton. " Stratified rock which can be removed by pick and bar . . . and masses between 3 cu. ft. and 1 cu. yd." Great Northern. " Slate and other rock, and loose enough to be removed without blasting, although blasting may be occa- sionally resorted to. Detached stone 3 cu. ft. to 1 cu. yd. Atchison, Topeka and Santa Fe. " Hard shale or soapstone . . . in original or stratified position, boulders in gravel, cemented gravel, hardpan . . . and other material requiring . . . use of pick and bar or which cannot be plowed with 10-in. plow and 6-horse team." Illinois Central. (No loose rock. Everything but solid rock classed as common excavation.) Northern Pacific. " Slate, soft sandstones, or other rock that can be ... removed without blasting 1 . . . detached rock between 1 cu. ft. and 1 cu. yd." Missouri Pacific. " All rock . . . which requires for its removal steam shovel or pick and bar, without blasting, although blasting may be resorted to at the option of the contractor. Detached masses 1 to 18 cu. ft." A composite view of the several descriptions of rock and loose rock would reduce to about this: Rocky material which can be removed without blasting is loose rock; and that which cannot is MEASUREMENT, CLASSIFICATION AND ESTIMATING 33 solid rock. That word " can " is the whole of the question, the uncertainty of the answer to which causes most of the disputes about classification. Taking a general view, the difference between materials in a construction sense is obtained by the writer from consideration of the operations necessary in loading such material. Earth is a material which can be reduced to loading condition by plowing or equivalent inexpensive picking or blasting. Loose rock is a ma- terial which generally can be put into handling shape by picking, barring and light sledging, or, in lieu thereof, by moderate blast- ing, but it is not quite as easy to load as earth. Solid rock is a more refractory material, requiring drilling, strong explosives, and general sledging; and, with this additional expense, is not capable of reduction to a loading condition as favorable as the other materials. Can a physical uniform test be applied? It is known that cer- tain soft or fractured rocks can be picked or barred apart with reasonable rapidity, and customary specifications state the fact, but do not state the rate. By definition of that rate the classifi- cations of rock oan be clearly defined. The writer thinks that, keeping close to current practice in classification, the rate of disintegration for loose rock should be within the performance of two men thus employed. A material requiring mo.vi than two men working with pick and bar to keep one shoveler busy is cer- tainly a material that " may better be removed by blasting " and which " can only be removed by blasting," in a reasonable sense, A consideration of importance is the size of the rocky mass that must be exceeded in order to constitute a solid-rock classification. In hand-work an isolated mass of 3 cu. ft. can be handled without much difficulty; but any larger mass will require disintegration before loading. The expense of this disintegration per cu. yd. will.be higher than that for disintegrating masses of the same ma- terial which, under any size limit, would still be solid rock. In steam-shovel work very considerable masses can be loaded without disintegration, and, consequently, without much real extra ex- pense. An objection to a small size limit would be an apparent necessity for more particularity of measurement. As to that, the separate quantities in mixed material, in practice, are approxi- mated percentages, and are as easy to calculate with one size limit as another. Bearing in mind the theory of trying to fix classification by similarity of cost, the writer thinks that 1 cu. yd. the limit most frequently specified is too high; 3 cu. ft., although right in one view, is probably too lo*v; and that the compromise limit of % cu. yd. would be about right. This limit was formerly common, and is still retained in some specifications, 34 HANDBOOK OF EARTH EXCAVATION In an endeavor to set forth the foregoing more clearly, Mr. Den- nis proposes the following as an outline classification: Excavation, excepting foundation pits for structures, elsewhere classified separately as foundation excavation, shall be either clas- sified or unclassified, as may be determined at the time of the contract. If classified, the following classification shall apply: Earth. Material which in its customary natural condition can be plowed or is equivalent to a material which can be plowed with a plow cutting a furrow 10 in. wide and 10 in. deep, drawn by a team of 4 horses, or mules, each having an average weight of 1,100 lb., and moving at a reasonable plowing speed, shall be classified as earth. Loose Rock. The following shall be classified as loose rock: Earthy or mixed materials, not susceptible of plowing under the foregoing test; soft, fractured, disintegrated or other rocky material, soft or loose enough in its natural condition to be barred or picked apart by two men thus employed serving one man shoveling or loading by hand; solid rock in separate masses ex- ceeding 1 cu. ft. each, and not exceeding y 2 cu. yd. The contin- uous or occasional use of explosives, at the contractor's option, shall not affect the classification, but it shall be governed solely by the test above set forth. Solid Rock. The following shall be classified as solid rock: Rocky material in masses exceeding y 2 cu - y!'^ ii/4- v? '* *o c iX* SKETCH OF TEST BORING RIG ARRANGED BY COMMISSION ON ADDITIONAL WATER SUPPU LONG ISLAND DEPARTMENT FROM JUUY TO SEPTEMBER 1903 SCAi.r or FEET '^i* Ifrrb. oilT >ff<>! fKi)ni f iiioj i'i: aU>Il . ->Jvii(1 t>') ii *ni IKI >Iii>i -nl't.aono -,HT rift,? [ rcf 3 Sut-foce of Ground Fig. 10. Rig for Wash Boring Finally Adopted liy Commission. 54 HANDBOOK OF EARTH EXCAVATION a report by M. E. Witham published in Engineering Record, Nov. 27, 1909, for the following data of the method and cost of making wash drill borings for the Stanley Lake Dam near . Denver, Colorado. This dam had a length at the crest of 9,140 ft. and a test hole was sunk 'every 200 ft. on the axis of the dam, and at intervals of 100 ft. on the line of the outlet structure under the dam to depths of from 20 to 80 ft. The site of the borrow pits from which material was to be taken was also bored. The drill used, of the spudding type, was a No. 4, 8-hp., combination hollow-rod Cyclone machine, mounted on a 4-wheeled truck. Holes 2} in. in diameter were drilled with 1^-in. hollow- rods having a center bore of % in. The operating force consisted of a drill runner, a fireman, and a sample collector. Coal and water were delivered by team. Coal cost $3 per ton at a mine 7 mi. distant. The water was brought from adjacent irrigating ditches. The drill runner re- ceived $5 per day and board, the fireman $2, the sample col- lector $3, and the team and driver regularly employed $4. Extra teams and drivers cost at the rate of 80 ct. per day for the entire time occupied by the work. The first 9 days were occupied largely in putting the drill in proper shape. The average time consumed in taking down the drill, moving 200 ft. and setting up was 2 hr. and cost about $3. In satisfactory material drilling cost 30 ct. per ft. of hole; about 10 ft. of hole per hr. was drilled. In troublesome material where casing was required the cost was 60 ct. per ft. Maximum Cost Hole: Depth, ft. Surface clay, mixed sand and gravel 5.5 Yellow mud 10.2 Yellow clay 24.0 Blue clay 32.0 (hard) 47.9 (soft) 48.9 (fine) 65.0 (light) 71.6 (hard) 72.4 (soft) 83.5 Total depth reached 90.0 Expenses : Salaries $58.60 Board 6.00 Coal 2.10 Cost of 90 ft. at $0.74 $66.70 Minimum Cost Hole: Depth, ft. Surface clay and sandy yellow clay 6.0 Mixed blue and yellow clay 19.0 BORING AND SOUNDING 55 Depth, ft. Blue clay (hard) 40.0 Total depth reached 60.0 Expenses : Salaries $13.50 Board 1.50 Coal . 1.00 Cost of 60 ft. at $0.27 $16.00 Total for 2,481 ft. drilled: Salaries Board Coal Teams Repairs, supplies, etc Total, 2,481 ft. at $0.43 $1,073.95 Cost of Borings at Cristobal, Panama. E. B. Karnopp gives the following information in Engineering News, June 16, 1910. Wash drill and diamond drill borings were made to determine the material beneath a proposed dock for the Panama Railroad at Cristobal. The pipe used in earth consisted of a line of casing 2y 2 in. in diameter, in the interior of which was a line of hollow rod 1% in. in diameter. A tripod derrick drum and wheel attachment was employed for hoisting the pipe. The tri- pod was of 2 x 4 in. and 4x4-in. timber, and was 18 ft. high. Six men were able to carry it when folded. The casing was made in 5-ft. lengths with flush joints, the first section having a flaring toothed cutting edge. In sinking, this pipe was revolved with chain tongs, and was assisted occasionally in its descent by an iron jar weight of 100 Ib. The hollow rods were 5 and 10 ft. in length, the lowest one being fitted with a chopping bit and the top one with a water swivel. In work where the wash drill process was too slow to be economical, a hand-power dia- mond drill was used. For details of diamond drill outfits and the method and cost of their operation see my " Handbook of Rock Excavation." For boring holes under water a staging was erected on piles. Water was obtained from the city mains. Boring operation occupied 7 months, and over a length more than a mile 235 holes were drilled. The equipment comprised 3 drills, each operated by a white foreman and 6 negro laborers. Pipe laying, staging-building, the handling of material, and all surveying work was done by an extra gang of 6 to 10 laborers. Foremen received $150 50 HANDBOOK OF EARTH EXCAVATION gold per month and laborers 13 to 18 ct. United States currency per hr. A recorder and draftsman were also employed. The following table gives the total cost and the amount of work done. 15.183.1 ft. of earth borings, at $0.587 per ft $ 8,91725 1,217 ft. of rock borings, at $2,536 per ft 3,087.42 16.400.2 ft. Total at average cost $7,319 per ft $12,004.67 Cost per ft. Earth Rock Supervision and surcharge $0.054 $0.227 Foreman 107 .449 Labor drilling 147 .616 Extra gang and driver 124 .520 Drafting and recording 070 .292 Materials consumed 065 .349 Repairs 020 .083 Totals $0.587 $2.536 Wash Borings, Winnipeg Aqueduct. Douglas L. McLain, in Engineering and Contracting, April 7, 1915, gives the following: Wash borings were made for the Intake Site and at the Falcon River Crossing with a " string of tools " which, though complete for the purpose, was not as elaborate as that necessary for deep drilling. The Irat of equipment with cost of same, given in Table 1, may be used for reference when similar work is con- templated. TABLE I. LIST AND COST OF EQUIPMENT FOR MAKING WASH BORINGS ON WINNIPEG SHOAL LAKE AQUEDUCT Unit . Quantity and description price Cost 50 ft. 2Mrin. extra heavy pipe (drive casing) in 5-ft. lengths. $0.57 $ 28.50 Cutting and threading pipe 5.00 50 ft. 1^4-in. heavy pipe, five 4-ft. lengths and six Sift. lengths 25 12.50 Cutting and threading pipe 3.30 10 2%-in. couplings 16 1.60 11 1%-in. couplings 08 .88 1 malleable 1^-in. tee 16 .16 1 double run 10-in. wooden block 1.85 1.85 60 ft, %-in. manila rope, per Ib 14 1.40 1 hand force pump R. 470 30 gal. per minute 7.00 7.00 2 24-in. Stillson wrenches 2.25 4.50 15 ft. 1%-in. discharge hose 30 4.50 20 ft. 2-in. suction hose 35 7.00 1 l^-in. street elbow 15 .15 1 1%-in. coupling for hose 30 .30 1 2 x lV 2 -in. bushing 10 .10 1 l^j-in. short nipple 10 .10 11% x 2-in. nipple 10 .10 1 drive weight 7 in. diameter by 15 in. long, 2-in. hole all the way through long dimension, widened to 3% in. from 4 in below top to top 3 ft. of y\ -in. flexible wire rope for handle 5.60 5.60 BORING AND SOUNDING 57 Quantity and description price Cost 2 1%-in. chopping bits of drill steel with Ui-in. theads 8 in. long |6.00 $ 12.00 6 pairs lumberman's rubbers, two buckles, sizes 10 11 and 12 1.60 9.60 1 pipe vi.se to take 2%-in. to IVi-in. pipe 2.CO 2.00 1 2-in. foot valve 45 .45 1 machinist's hammer . ... 1.10 1.10 2 cold chisels ; [35 .70 1 pair jacks, 2 in. by 18 in., with handles 6.80 13.60 Steel spindles for same, per Ib 10 1.20 2 sleeve couplings, 1^4-in. W. T. 10 !20 3 sleeve couplings, 2%-in. W. T 16 .48 2 1%-in. nipples, 6 in. long 06 !l2 2 1^-in. to Q4-1B. reducing couplings 10 .20 2 1%-in. nipples, 6 in. long 08 ,16 6 1-gal. pails 21 1.26 1 pint machine oil, black 15 .15 1 2-in. nipple, 6 in. long 10 .10 1 recovering tap 3.75 3.75 2 sister hooks 2.50 5.00 1 clasp for 2y 2 -in. pipe 2.00 2.00 1 hoisting ] Ing 1.75 1.75 6 couplings for l^i-in. pipe (extra) 08 .48 1 ice chisel 3.50 3.50 2 axes. 3%-1b 1.25 2.50 1 air tight heater 2.10 2.10 1 length stove pipe 10 .10 3 chain tongs, No. 33 Vulcan 4.50 9.00 2 pairs extra leather (front and back) for piston of Meyer's low-down force pump 35 1.40 3 logs for tripod Delivery from C. P. R. station to site (18 miles) 12.10 Total $171.54 With this equipment, the process of sinking the test holes waa very simple and usually was as follows: The derrick or tripod, consisting of three logs, was set up over the station where a hole was cut through the ice and the depth of water obtained by sounding. After this suitable length of casing was put down ; at the same time a hole for the pump suction was made and a fire started in the heater to warm water, which facilitated the thawing of the tools. Then drill rods of the required length with chopping bit on lower end and hoisting water-swivel on upper end connected to derrick-rope and by hose to the force-pump, were put down inside the casing. The position of the bottom of the casing and the drill rods having been noted, the drill rods were churned up and down by means of rope over block attached to tripod. At the same time water was forced down the center of these rods to the outlet in chopping-bit and then up between the rods and the casing. The chopped material brought up by the water jet was noted by the leader in charge of the work. To sink the casing, chain tongs were attached and it was rotated. This rotation or turn- ing of the casing to keep it free from sticking to the material 58 HANDBOOK OF EARTH EXCAVATION drilled through, was the detail that added most to the speed of work, not only in sinking the casing, but more especially in the pulling of the pipe. This method of sinking the casing was not practical at all times and in such cases the drive weight was used to pound the casing down. After it had been used it was necessary to use two jacks to draw the pipe. As the hole was sunk either by rotation of casing, or driving, constant watch was kept of the position of the bottom of the casing and the drill rods, together with careful note of the materials brought up by the water jet. For this particular piece of work at Indian Bay it was found advantageous to use a force of one leader pr foreman and four laborers. The progress that can be made under winter conditions and the cost of same is given in Table II. This gives total and aver- age figures on the footage, the materials encountered and the labor and food costs and should be of use for information when similar work is contemplated. The force on this work usually consisted of 1 topographer at $3.95 and 3 laborers at $2.55 each, or 1 foreman at $2.80 and 4 laborers at $2.70. The work was done, with the exception of one day in December, between Jan. 9 to Feb. 27, 1914. The thickness of ice ranged fairly gradually from 1.46 ft. on Jan. 9 to 2.60 on Feb. 9. On that day the tem- perature dropped to 35 and work was discontinued until Feb. 24, when the temperature was +5 at 7 A. M. and the thick- ness of ice was 3.17 ft. TABLE II. WASH BORINGS AVERAGE COST DATA FOR WINNIPEG AQUEDUCT Depth of Totals Average Water 523.0 Muck 45.3 Clay 594.2 Sand 73.7 Gravel 31.7 Depth of material bored 744.9 27.6 Total length of casing, includes ice, water and material 1,267.9 47.0 Labor and food cost $404.75 $15.00 Cost per ft. below lake bottom $0.541 Total cost per ft. of casing in ice, water, material $0.319 Wash Borings for Railway Valuation Work. George H. Burgess, in Engineering News-Record, April 5, 1917, gives the following: Like other roads the Delaware and Hudson has sec- tions along the shores of Lake Champlain, for example where there has been much subsidence. The records showed much of this, but were incomplete. Wash borings were resorted to, and the company profited more or less by the experiences of other roads that faced the problem sooner. Bids were asked BORING AND SOUNDING 59 iti'l' *V}~{"i<>'i "iI)!-><{ fiffifJ' 'ii i ! i ir '/ -'JiK / f " f for, but they contained so many conditions that the company decided to do the work by company forces. Two simple outfits were made in the company's shops. In addition, two Sheffield hand-cars and four standard track jacks were bought, and a 6 x 20-ft. scowboat was built for use where the fill crosses bays of Lake Champlain. The working force consisted of one foreman at $2.85 per day, five men at $2.75 and a recorder at $50 per month. The fore- man and his men were also allowed $1 each per day, and they lived in a maintenance-of-way boarding car, cooking their own meals. They were company bridge carpenters. The recorder was a rodman from the survey party, and his expenses were about $2.25 per day. The cost of boring outfits was as follows: 2 double A-frame drilling outfits $299.22 4 standard track jacks 43.36 2 Sheffield hand-cars 63.00 1 boat 101.30 Total T $506.88 In a report by Mr. Mansfield, the company's valuation engineer, it is pointed out that the outfits can be used to great advantage by the maintenance-of-way department when the valuation de- partment is through with them. By the use of the outfits over an aggregate of about 12 miles, 1,870,883 cu. yd. of filling material and 45,603 cu. yd. of riprap were discovered. This work was done at a total cost of $1,570 exclusive of plant investment or at a cost of 31.82 ct. per lin. ft. inclusive, or 25.56 ct. exclusive, of the recorder. The total cost per yd. of all material disclosed was less than 0.1 ct, per cu. yd. Wash Borings on the Ashokan Dam Site. A paper by J. S. Langthorn, in Engineering and Contracting, June 23, 1909, de- scribes the methods used in making wash and diamond drill bor- ings for the Ashokan dam site in the Catskill Mountains. The diamond drill work is described in my "Handbook of Rock Ex- cavation," as are also the pressure tests of the bore holes to determine the seaminess of the rock. The methods used to interpret results of wash boring on this work were of special interest. One man was able to take care of four boring rigs, and one test pit, and to take ground water observations on completed holes. He took samples on holes in progress, water observations on completed holes, assisted in lo- cating holes and made monthly estimates on test pits. A one- horse conveyance was used to travel from one boring to another, when they were at some distance, and also to carry core boxes, sample bottles, marking boards, etc. CO HANDBOOK OF EARTH EXCAVATION Dry and wash samples were placed in small bottles, corked and carefully labeled. These were placed in drawers which were systematically arranged and so subdivided that the samples from any hole could be readily found. Fig. 11. Outfit for Making Wash Borings on Ashokan Dam Site. Upon being removed from the core barrel of the boring ma- chine all cores were stored in core-boxes. Each box contained BORING AND SOUNDING 61 room for four rows of core in the bottom of the box together with three shelves for three rows each. A box would hold about 37 ft. of core, whicli generally represents about 40 ft. of actual drilling. The core was labeled, boxed and stored in a small portable building shelved on all sides, where the core boxes were properly painted with number and depth of hole. Here they were readily available for future inspection. In addition to the core boxes, cabinets containing drawers were provided for filing the samples. Instructions to Inspectors of Borings. A copy of the following instructions was given to each inspector for his guidance: These borings and test-pits are being made to ascertain: The character of the overlying material; the elevation of bed-rock; the quality of this rock and incidentally all data that would aid in the selection of the best dam site. In order to get an accurate determination of these conditions much depends upon the faithfulness and good judgment of the observer. His interpretation of the material must be based on the samples taken and careful observation of the mechanical operations of the machines and the wash which comes up through the casing. The following are some of the general rules which the inspector should be careful to note. 1. Observe very carefully the character of the material washed up and the color of the escaping water. Upon the proper in- terpretation of the above depends very much the value of the test hole; for, no matter how good or how accurate the samples may be, the true nature of the ground is best obtained by ob- serving the mechanical operations involved. For instance, the wash may be clayey while the sample will contain no trace of clay; but the observer should record clay present as noted from the discoloration of the escaping water. 2. Take a sample for every 10 ft. driven and, if the material changes rapidly, a sample should be taken at every decided change. Should less than 10 ft. be made in a day, one sample will then be sufficient. There are two methods of taking samples of materials. A, the dry method, B, the wash method. A, the dry method, is by far the more satisfactory when very accurate results are required. It is, however, an expensive and tedious method of procuring results. A l^-in. perforated wrought-iron pipe is driven into the material below the casing. The pipe has holes in it so that the water may be easily displaced when the sample of compact material enters the bottom of the pipe. For sand or material which would fall out of the sample pipe on being lifted, a " sand spoon " is used, a pipe with a closed pointed end, with a slit or opening about 1 ft. from the point. 62 HANDBOOK OF EARTH EXCAVATION This is driven into the material, and, on pulling it up, the sand enters the spoon and is so brought to the surface. In this way the material is obtained just as it exists. B, the wash method, is as follows: In a tub or a half-barrel with a glass panel in one side, the wash, which comes up through the casing, is allowed to flow. If conditions are right and the tub becomes full, it is placed at one side and about a teaspoonful of hydrochloric acid mixed with water. The action of the hydrochloric acid is very decided. It takes about 30 min. to settle, while with no acid, it would take half a day. The settlement of the material may be seen through the glass panel. When settled, siphon off the clear water and the washed sample remains. Fill a sample bottle with the material, label with date, depth of hole and description of material. Take dry samples, owing to their expense, only of material which may be regarded as porous, i. e., sand and gravel, sand, or sand with a little clay; otherwise the wash sample, combined with the proper observations, will serve all general purposes. Kever take a sample directly after a blast, nor when the wash pipe is too far ahead of the casing. The best time is when the wash pipe is about 3 in. ahead. 3. Make a concise record of the action of water in all boring operations. Should the water forced down the wash pipe fail to come to the surface again, it should be recorded as. " losing water." This would signify that the material is water bearing or porous, or it may be a seam or cavity such as may exist in rock. Should the water stay at the top of the pipe it would show the impervious nature of the underlying material. The water may flow out of the top of the casing, indicating that a stream of water has been encountered with a greater head than that in the pipe. 4. It will not be sufficient to report a material as " clay and sand," for clay and sand in different proportions and under different conditions may vary from a very soft material to hard- pan. They may be stratified or exist as separate pockets or closely intermingled, and all these conditions may be upset when water is present. A proper description should read as follows: From 90 to 100 ft. Hardpan, i. e., clay, small stones and boulders in a very compact mass. Must use dynamite almost constantly in order to make any progress. From 100 to 140 ft. Clay and sand. Material very soft, the weight of rods being sufficient to penetrate material which stands up well and does not fill in when casing is removed. 5. The inspector must bear in mind the possibility of large BORING AND SOUNDING 63 boulders existing, and should constantly be on the lookout for indications of them in the drilling. NOTE: In this locality boulders greater than 20 ft. in any dimension were not met with, but some were found that were 10 or 12 ft. through. Consequently, when bedrock was reached, it was decided to drill 20 ft. to make certain it was not a boulder. Conclusions. The experience gained in the borings at the Ashokan Reservoir led to the following conclusions: 1. A washed sample without proper observations was of no value as a record, while greater weight given to the inspection of the boring operations would approach the actual conditions much nearer. 2. A dry sample was more satisfactory, but, without the in- spector's observations, was not sufficient. 3. Invariably the proportion of clay given in boring records was too small. 4. The coarser materials, such as boulders, cobbles, etc., were not given enough weight. 5. Small stones would be chopped up by the bit and on com- ing up through the casing would be interpreted as sand. 6. If water was lost it was in a pervious material or water- bearing stratum with little or no clay present, or a seam in rock. 7. If material was recorded as " sand and gravel " with no loss of water, it was probably an incorrect record, for clay gen- erally was present. 8. The percentage of core obtained, everything else being equal, varied directly with the hardness of the rock. 9. A larger percentage of core was possible with a bit of large diameter. 10. The conglomerates and harder sandstones yield nearly 95%, while the softer, loose and tilted shales yield less than 25% of core at best. 11. A good hard rock suitable for foundation or construction may be granular or nodular in texture and consequently give very little core and that very seamy. This core would be re- corded as seamy and would give a false impression of actual characteristics. 12. The amount of core should be but a small factor in a general determination of the quality of the rock. The improper setting of a bit, excessive vibration of the rods, too strong a force of water, or the grinding away of the* core, will reduce the amount obtained. 13. Vertical seams will reduce the amount of core. One case is worthy of mention : Ten feet had been drilled and the working 04 HANDBOOK OF EARTH EXCAVATION of the machine showed no unusual conditions. On pulling up the core barrel, it was found that only 1 ft. of core 'had been obtained. A weighted tape was dropped into the hole to see whether any core was left, but the hole was found clear and empty. By careful inspection of the core that was obtained, the presence of a vertical seam was discovered. The machine showed no indications of soft rock or horizontal seams in the running, the wash came up throughout the run with good blue stone cut- tings. It was concluded, therefore, that the bit had been in a vertical seam and was cutting good rock with its outside dia- monds and consequently no core was made and a report to that effect was sent to the office. 14. It is possible from inspection to see whether detached pieces of core are broken mechanically or whether seams exist. 15. Boulders greater than 12 ft. in vertical dimensions were not encountered in the glacial till of this section. Boring with Augers. A common wood auger, welded on to the end of lengths of gas pipes or other rods and turned by men with levers, may be sunk from 25 to 100 ft. in ordinary earth. When sand is the material to be penetrated, an outer casing of pipe may be driven with mauls or weights in order to prevent the sides of the hole from caving in. Hardpan, gravel and diffi- cult materials cannot be penetrated by augers. For ordinary materials, however, this method will give fair results if the observations are made with care and intelligence. Some so- called earth augers are not true augers but are really spoons or pods which are twisted or driven down into the soil and then raised for removal of the spoil. Care should be taken not to drive the spoons or augers too deeply without raising them for cleaning. All devices of this character tend to show the earth penetrated as being more compact than it really is. A Simple Boring Device. In commenting upon the failure to investigate the foundation of a high embankment in Engineering and Contracting, May 17, 1911, the writer described a very sim- ple boring device. The instrument is a bar of hexagon or octagon steel, the end of which is swedged and enlarged at the butt and tapered to a point at the ends; the sides of the head are corru- gated with a cutting edge. (Fig. 12.) On the opposite end the bar has a T handle riveted firmly to the shank, and this shank or rod may be 20 to 25 ft. long, often more. The method of operating is to raise this rod to a vertical position with the sharp bit on the ground, and then by churning the rod drive it into the earth until the bit reaches an obstacle. If continued churning does not remove or penetrate the obstacle in its path, several hard churns will dislodge particles from the obstruc- BORING AND SOUNDING 05 tion, and by twisting the handle around several times the particles will lodge within the cutting edge of the bit, and may be brought to the surface, where they may be examined. In open-cut mining work, it was customary to lay off a tract of land to be examined in squares of 10 ft., so that each square contained 100 sq. ft., staking the corners. At each stake sound- ings were taken to the ore bed. Two men were sufficient, and they were capable of sounding from 10 to 15 holes per hr. [ngConlg. I Round Iron* *| Hex or Octagon Drill Site/ Cutting &gn Fig. 12. Sketch of Device for Boring. A Hand Auger for Prospecting. The hand auger shown in the accompanying illustrations, from Engineering and Contracting, Jan. 19, 1910, was developed by Baird Halberstadt, engineer and geologist, Pottsville, Pa., in the course of his work in prospecting some new coal fields in West Virginia. The tool, Fig. 13, consists essentially of four parts a heavy auger, a handle, a cutting bit and a number of sections of 1-in. gas pipe (one 8 ft., the others 3 ft. in length), threaded at both ends and fitted with ferrules. The auger is made of ^-in. steel, 4 turns in 13 in., rounded and threaded to fit the ferrule, and to this are screwed the sections of pipe as the depth of the hole increases. It has been found well to have the first section made longer than the others, as the handle can be passed up and down as required without entirely uncoupling it, as becomes necessary when passing over a ferrule. The handle is made in two sections, HANDBOOK OF EARTH EXCAVATION as shown in the drawing; the joining ends are held firmly by two bolts, and a circular hole drilled of a diameter slightly less than that of the pipe. With the bolts tightened up fully, the pipe will twist before the handle will slip around the pipe. For holes exceeding 10 ft., when loose rock is encountered, a cutting bit replaces the auger until the obstruction is passed Fig. 13. Auger for Making Test Borings. through. It has been found that greater speed can be made by using for holes where obstructions are met at a depth of less than 10 ft. and more than 4 ft. Ordinary jumpers are made of 1^-in. octagon steel of good quality. The bits are of the round rather than triangular shape. Two of these are usually carried with the party, one 6 ft. and the other 10 ft. long. Fig. BORING AND SOUNDING 67 14 fully explains the forms of each of the parts. Any good colliery blacksmith should be able to make one at a cost not to exceed $15. The outfit consists of 2 auger bits (one for any emergency, although but two or three were broken in drilling the 65 miles outcrop), a cutting bit, 2 jumpers 6 and 1() ft., one-half dozen 18-in. bastard files for sharpening the blades of the auger, an I Fig. 14. Details of Bits for Test Boring Auger. 8-lb. striking hammer, an 18-in. Stilson pipe wrench, a monkey wrench for loosening the bolts in handle, a galvanized iron bucket and tin cut, a mattock and short handle shovel, an oil cadger filled with lubricating oil for use on ferrules and pipes, and a short handle cutting axe. The entire outfit can be carried readily by a party of three men almost anywhere. In fact where the holes are not far apart two men by making an extra trip can transport them. It 68 HANDBOOK OF EARTH EXCAVATION has been found advantageous to use three rather than two men to a crew, as three can work to far better advantage, and the dilference in cost is more than made up by the increased amount of work accomplished. If the hole is on the slope of a hill, a space of say 2i/ to 3 ft. square should be leveled off with a mattock and spade. This gives the men firm foothold. The auger (attached to an 8-ft. section of pipe to which the handle is securely fastened) is put down and the handle turned until the auger has cut through 7 or 8 in. of "wash"; it is then removed and a cup or two of water is poured into the hole and drilling is resumed. The purpose of the water, if the ground is very dry, is to dampen the soil, but not to make it too wet. The material cut through will then cling to the auger, filling the grooves, and the whole can be quickly removed when the auger is withdrawn. On each drawing up of the auger a small quantity of water is introduced. The advantage of the auger over the churn drill is here ex- hibited, for with the former neither a scraper, swab stick nor sand pump is required, while with the latter the whole mass must be made pasty, so that it can be drawn up with swab stick or in a sand pump. Another advantage the auger has is that the sides of the hole become packed hard and no diffi- culty is experienced from caving in. The holes drilled with it, if covered, remain open for many months. The sand pump was used only in extremely wet holes and generally it was only necessary to use it when holes were drilled near water level. Throughout this entire work the sand pump was resorted to in but a few instances. Hook Connections for Auger Rods. These were used in mak- ing subsidence tests on the Chicago, St. Paul, Minneapolis and Omaha Railway, as described by M. M. Wilcox in Engineering News- Record, May 3, 1917. As some of the holes bored were more than 50' ft. deep, to unscrew joints every time the auger was pulled up for cleaning would have been slow work. With the hook connections the rods were disconnected as fast as they were lifted from the hole, and still there was no chance for them to become dis- connected while in a vertical position. The tools used for the tests were a carpenter's 2-in. auger, a 2-in. pod auger, a short drill, two bars, 5 and 8 ft. long re- spectively, both of 1-in. drill steel, a supply of 2-in. single- strength pipe and couplings for casing the hole in soil that caved, a Channon pipe lifter with a Little Giant pipe holder, wooden mauls for driving the casing, a shovel and post-hole digger for use in going through the ballast, a short piece of BORING AND SOUNDING 89 heavy log chain with hook and eye, two pipe wrenches and a supply of extension rods. The augers and drill each had a shank 4 ft. long with an eye at the upper end so that an extension rod could be hooked on as the hole was lowered. These exten- sion rods were of }-in. round steel, 8 ft. long, with an eye at one end and a hook at the other. There was one rod 4 ft. long to use in connection with the longer ones, so that there was never more than 4 ft. out of the ground at a time. The method followed in making these tests was to put a hole through the ballast with the shovel and post-hole digger, than set in a length of the 2-in. casing and use the auger the rest of the way, lowering the casing as the hole progressed. If the fill was of clay or any material that would stand without caving, it was often possible to complete the hole with only the one piece of pipe, as that would keep the ballast out of the hole. Where the fill was dry sand, or if there was water h" A lof4 L 0'' ->/ Fig. 15. Extension Bar for Boring Auger. on the sides of the fill, it was necessary to keep the casing close to the bottom of the hole; and in some holes better progress was made with the casing driven lower than the hole, the ma- terial being bored out inside of the casing. In a number of holes small gravel stones were found which caused a great deal of trouble, until a 3-ft. piece of 1^-in. pipe (the largest that would go inside the 2-in. casing) was fitted with an eye at one end so that the extension rods could be hooked in. This pipe was churned up and down in the hole until the gravel had become wedged in the pipe. In this way any stone that would go in that pipe could be removed. At times the stones were too large to be removed in that way, and it was necessary to drive the casing down until the stone was wedged in it. The casing was then pulled and cleaned. In some holes it was possible to replace the casing without losing any of the hole, but at other times it was found that from 5 to 50% of the hole had filled and would have to be bored out again. Auger Borings on Sewer Construction. In Engineering and 70 HANDBOOK OF EARTH EXCAVATION Contracting, March 23, 1910, Roger DeL. French describes test borings for sewer construction at Louisville, Ky., where wash borings were taken on the line of proposed sewers by a superin- tendent and (usually) four men. Oftentimes a bore hole could be put down to its full depth with a post-hole auger, but small holes required to be cased with 4-in. pipe and sunk with a sand pump. The cost of these holes ran from 2 ct. to as high as 20 ct. per ft., according to location, material penetrated and number of holes in one group. Four men and a superintendent could put down an average of 180 ft. per day of 8 hr. in the clay, sand and gravel underlying Louisville. Cost of Test Borings for the Winnipeg Shoal Lake Aqueduct. Much test boring was done during the winter of 1913-14 in ex- amining the proposed location of the aqueduct from Shoal Lake to Winnipeg. A description of this work and cost data are Fig. May 16. Ice Thickness and Temperature Curves for Indian Bay, Shoal Lake/Greater Winnipeg Water District, 1913-14. given by Douglas L. McLean in Engineering and Contracting, April 7, 1915. This work was carried on under the severe climatic condi- tions of a Manitoba winter. Maximum ice conditions on Shoal Lake from December, 1913, to June, 1914, are shown graphically BOKING AND SOUNDING 71 on Fig. 16. This chart shows the growth of the ice from day to day on an ice space kept clear of all snow. Corresponding to the curve of ice thickness is a temperature curve to show the amount of cold which produced this ice. In order to measure this in degrees below freezing over a stated period, the ordinates for the curve were taken as " degrees Fahrenheit below freezing times one day." The maximum depth of ice on snow covered portions of the lake was 2.3 ft. thick as compared to 3.2 ft. on clear space. On the peat bogs the depth of frost averaged about 2 ft. The maximum depth of frost encountered was 3.7 ft. in sandy soil while the minimum in sheltered snow covered places was 1.5 ft. The located line for the section of the aqueduct on which Party No. 3 made borings ran for the most part through a clay country covered with peat bogs. For the seven miles from Snake Lake to the Boggy River the peat bog averaged about 8 ft. in depth. Cost data relating to a portion of the test boring work are given under the following headings : ( 1 ) Salaries and board al- lowance. (2) Empire drill costs. (3) Hand auger costs. (4) Wash boring costs. Salaries and Board Allowance. The following were the stand- ard rates paid by the Greater Winnipeg Water District: Instrumentman, per month $100* Leveler, per month 90 Topographer, per month 75 to $80 Field draughtsman, per month 60 to 70 Rodman, per month 40 to 45 Head chainman, per month 40 to 45 Rear chainman, per month 35 Head picketman, per month 40 to 45 Cook, per month 60 to 75 Cookee, per month 35 Leader, per day 1.75 Laborer, per day 1.50 * All grades were boarded free while in the field. An additional allow- ance of 15 ct. per day per laborer while on boring was given to make up for extra wear and tear on mitts and clothing. For the boring costs given in this article a board allowance of $1.05 per working day has been charged. . Empire Drill Costs. Total and average costs for 645 ft. of boring using the small auger drill spoon with necessary drill rods, wrenches and handles of a Junior Empire Drill Set, are- given in Table I. The Junior Empire Drill Set ordered by the district cost $260 delivered at Winnipeg. It was supplied by the New York Engineering Co., whose catalog gives a complete description of its various parts. The test holes put down. wer& 72 HANDBOOK OF EARTH EXCAVATION at 2,000-ft. intervals, averaged 22.2 ft. in depth and cost 32.4 ct. per ft. run, including the peat in the depth. In opening up the holes through the frozen material axes were used on all hand auger work, as the axe was found more efficient than a chisel, crowbar or pick. TABLE I. HAND AUGER TEST BORING COST DATA, WINNIPEG AQUEDUCT (Small " Empire Drill " earth auger used without casing as hand auger) Totals Number of holes 29.0 Frost depth in feet, 1 55.9 Peat depth in feet, 2 234.1 Sand and gravel depth in feet, 3 09 Clay depth in feet. 4 409.7 Total depth in feet of 1, 3, 4 465.5 Total depth in feet of 2, 3, 4 644.7 No. of men per day or man-days 65.8 Cost per day $208.66 Work done from Feb. 4-:8 Feet Average depth frost per hole 1.93 (This is frozen peat and water.) Average depth peat per hole 8.07 Average depth sand and gravel per hole .03 Average depth clay per hole 14.10 Average total depth 22.20 Average cost per foot run, 1, 3, 4, ct 44.8 Average cost per foot run, 2, 3, 4, ct 32.4 Average cost per man-day .;. $3,175 Average man-days per hole 2.27 Average man-days per foot run, 1, 3, 4 0.141 Average man-days per foot run, 2, 3, 4 0.102 4- men gang Average cost per day $12.70 Average bored, 1, 3, 4, f< et per day 28.4 Average bored, 2, 3, 4, feet per day 39.2 Note. Cost of auger, axes, etc., not included in table. These holes were about 2,000 ft. apart and considerable time was required transporting outfit and traveling to cam]). Hand Anger Costs. Table II gives the cost of some 6,200 ft. of boring for which was used the hand augers shown in Figs. 17 and 1H. These hand augers give practically the same effi- ciencies for depths of 15 to 20 ft., but for depths under 15 ft. the pipe auger is the faster. The rod auger, Fig. 17, consisting of 1 auger piece, 1 handle, 5 extension rods with 12 extra bolts %-in x 114-in., cost $10.70. To this should be added cost of a couple of spanners and a handle for lifting. The pipe auger, Fig. 18, consisting of 1 auger piece, 5 rods with couplings and bolts, 1 handle, 1 extra set of bolts and 2 spanners, together with 2 only %-in. steel chains 4 ft. long, with one grab and one slide hook attached to each, cost $15. Al\D SOUiNUliNG 73 ' TJ t Elevohon of Hondle o f Cuthng Edge -" " End View Fig. 17. Hand Operated Rod Auger Used on Wippipeg Shoal Lake Aqueduct. TABLE II. HAND AUGER TEST BORING COST DATA, WINNIPEG AQUEDUCT Totals to April 22 Number of holes 370.0 Frost depth in feet, 1 759.6 Peat depth in feet, 2 2,490.9 Sand and gravel depth in feet, 3 59.3 Clay depth in fett, 4 3.352.3 Total dtpth in feet, 1, 3, 4 4,171.2 Total depth in fc et, 2, 3, 4 5,902.5 No. of men per day, man-days 236.9 Cost per day $662.70 ^_$ ]_, ' - : t ' , 1 \f Summary of results to April 22 Average depth frost per hole, feet 2.05 Average depth of peat per hole, feet 6.73 Average depth of sand and gravel per hole, feet... 0.16 Average depth of clay per hole, feet 9.06 Average total depth, feet Average cost per foot run of 1, 3, 4, ct 15.9 Average cost per foot run of 2, 3, 4, ct -11.2 Average cost per man-day $2.80 Average man-days per Hole 0.64 74 HANDBOOK OF EARTH EXCAVATION Average man days per foot run, 1, 3, 4 0.057 Average nian-da.\s per foot run, 2, 3, 4 0.040 3-man gang Avei age cost ptr day $8.40 Average bored, 1, 3, 4, feet per day 52.8 Average bored. 2, 3, 4, feet per day 75.0 Cost of equipment 3 rod augers at $10.70 $32.10 6 spanners at 20 ct 1.20 3 monkey wrenches at 70 ct 2.10 1 pipe auger at $15 15.00 4 10-qt. galy. pails at 21 ct 84 1 doz. 3i/2-lb. axes at $1 12.00 Total $63.24 This equipment cost is not included in table. Handle -Round steel of di men shown with welded joint .-'Square Shoulder . F N* CM| u_ Fig. 18. Hand Operated Pipe Auger. BORING AND SOUNDING 75 Boring with Hollow Pipe. In order to sample the material along the route of the proposed Boston subway according to Engineering News, Mar. 29, 1894, a pipe was driven down and then pulled up and the soil retained in the interior was removed. The depths reached averaged 25 ft.; a maximum depth of 38 ft. was obtained. A small derrick was used for pulling out the pipe and also for lifting the weight used to drive it. The earth which was forced into the pipe during the driving was in turn forced out by water, and a small tube was inserted into the pipe for the purpose of taking out samples. Hi mm Line or nnishea Basement mpi 9 b b b ; ! II Ml! i i j % Pea MVarer Level Gumbo - -: water --t and -'z r Quicksand z .It ))} SOU -GumbqLumpsor % Hardpan < Qutcksano r inesi 'oona, Grading rover y coarse Sand and Gravel Fig. 19. Depth of Test Holes and Character of Sub-Soil. Cost of Auger Holes in Oklahoma. Mr. F. O. Kirby, in En- gineering and Contracting, Jan. 14, 1914, gives the method and cost of determining the soil conditions beneath a proposed five- story office building at Chickasha, Okla. At one time there was a slough where this building stands, and as the town grew and the street was built up, the ground was filled in. In general, the soil on top of the ground to a depth of about 10 ft. was red sandy clay, with strata of gumbo and hardpan every few feet. Below a depth of 10 ft. the sand in the soil increased. The high-water mark during the wet 76 HANDBOOK OF EARTH EXCAVATION season was about 6 ft. below the street level, and the low point, as shown in Fig. 19, was about 17.5 ft. The same strata were found in each of the three test holes. The first test hole was taken in the center of the basement, and the other two were taken at each side of it. Holes Nos. 2 and 3 were made by a post auger, using pipe to lengthen the handle. No. 1 was started by driving a galvan- ized iron pipe in sections by leverage. At a depth of 25 ft. this pipe closed up so that it was impossible to get a 3-in. auger through it, nor could a sand bucket be used to clean out the pipe. A driver was then rigged up by using a set of leads with a railroad tie for a hammer. Laborers were employed to lift and drop the hammer, to drive a 4-in. pipe in 10-ft. sections, and to take out the soil with an auger and sand bucket. The cost of the three test holes shown in Fig. 2 (totaling 91 ft.) is given below. This cost is based on 1912 prices for ma- terials, the local union scale of 45 ct. an hr. for carpenters, 20 to 25 ct. for laborers, and 62.5 ct. for the foreman. The lumber in the derrick is not included in the cost, as it was used in the building. > $ Cost Driving test holes and removing wrought iron pipe, labor only $34.45 Carpenters, building derrick , 7.20 Carpenter, rigging 3.60 Post auger 2.00 15 ft. of 1-in. black pipe 1.05 15 ft. of 1 in. No. 22 well casing 2.70 1 sand bucket 4.75 12 ft. of 1-in. black pipe 0.78 27 ft. of 9 in. galvanized iron casing 6 75 2%-in. sand bucket 3.75 62 ft. of 3 l / 2 -in. black pipe 28.52 2 couplings 80 2 caps 0.90 1 B. coupling 0.40 4 cuts and threading 1.60 15V 2 -ft. of %-in. black pipe ' 0.78 2%-in. couplings 0.15 Cutting and threading 0.?5 Ring in pipe 0.15 4 guides for derrick 1.00 2 braces 0.50 Clamp to pull pipe ; JK9. . ; V. . &!<% ."WS^' A 2.00 24 ft. of 9-in. casing 6.00 Total cost of 3 test holes ;?.S?,JStt?... 9 .^/..Jtfl }?.'/! $110.03 Auger Boring with an Empire Drill. (Engineering and Con- tracting, Jan. 29, 1908.) The drilling is done with one of several tools, adapted to the particular kind of material being drilled attached to the drilling rod. The tool and rod are operated inside the casing by the men on the platform, who raise and drop them like a " churn " drill. The men on the BOEING AND SOUND1KG HHRHBIi Fig. 20. Sectional View of Empire Drill, Made by the New York Engineering Co., 2 Rector St., N. Y. 78 HANDBOOK OF EARTH EXCAVATION ground rotate the casing, which has a sharp cutting shoe on the lower end. The casing, with its burden of platform and men, thus keeps cutting and sinking into the ground several inches ahead of the tool. A horse may be substituted for the men who rotate the casing. The material which enters the casing is drilled and forced into a sand pump at the same time: The pump is occasionally lifted out of the casing, emptied and the contents noted. Four-in. pipe is generally used, with a special coupling that makes a flush joint; that is, all of the couplings have the same outside diameter as the pipe, which makes it very easy either to sink or remove this casing. Instead of the 4-in. pipe or casing, 3-in. or even 2^-in. casing can be used if desired, and it will make more rapid work, but of course would give a smaller core. After the hole is finished, the pipe is easily withdrawn be- cause the casing, having been constantly rotated, is always loose, both while sinking and 1 removing. In estimating the cost of operating this drill there is little else to be calculated besides the labor, as the repairs constitute a small part of the operating expense. Of the laborers employed, one must be a foreman or driller, another an ordinary pipeman, and the balance of the crew common laborers. When the casing or piping with its platform is rotated with a horse, instead of the men on the ground, it effects quite a saving in the cost by dispensing with three or four men. If the ground does not contain heavy boulders, and the holes are not over 35 to 40 ft. deep, six men will be sufficient, or three or four men and a horse. With the 4-in. size hole 50 ft. of hole per day have been drilled at a cost of 3.0 ct. per ft. Twenty-five to 30 ft. of hole per day will be averaged through hard cemented gravel con- taining boulders. Mr. Thos. G. Ryan used one of these Empire hand drills on Long Island putting down a number of holes through sand and gravel, with occasional strata of clay, and in some cases en- countering large boulders. About 40 test borings were made, each hole averaging 59 ft., the total being 2,454 ft. The time consumed in this work was 73 days, working 9 hr. per day. The cost given below includes the drilling, drawing the casing, and moving and setting up drill, thus covering a number of re- movals over a considerable period of time. The total cost of the work was: 1 foreman 73 days at $4 $292.00 1 pipeman 73 days at $3 , 219,00 BORING AND SOUNDING 79 3 laborers 73 days at $1.50 each $328.50 1 horse 73 days at $1 73.00 Depreciation, interest, renewals and incidentals 81.76 Total cost $994.26 An Empire drill was used under the direction of Mr. Clarence R. Snow, during the autumn of 1908, in Colombia, South America. An account of this work appears in Engineering and Contracting, June 8, 1909. The work was done with native peons or Indians, who had never seen machinery of any kind. The country in which the holes were being sunk was covered with forest, the bush and undergrowth in many places being very heavy. To move the drill from hole to hole a narrow path was cut through the un- dergrowth 6 or 7 ft. high. A small flat bottom boat was used to carry the drill across the river, there being consumed about half an hour to do this. As there are no roads in Colombia it would be almost impossible to work a steam drill, owing to the diffi- culty of moving it from place to place. Four men were used to turn the casing, and four men did the drilling, an additional man being used for cutting trails. The entire crew was used to draw the casing and move the drill from hole to hole. The following is a record of seven days' work: First day, Carried outfit across river in boat and began hole No. 1. Made 14 ft. in top soil and 11 ft. in gravel by 5 P. M. Second day, Finished hole No. 1, 2.5 ft. more to bed rock, total, 27.5 ft. Pulled casing. and began hole No. 2, 100 ft. distant before noon, and sunk the hole 17 ft. deep to bed rock before 4 p. M. Pulled casing and moved to hole No. 3, drilling 9 ft. in overburden. Third day, Finished hole No. 3, 24 ft. deep. Pulled casing and started hole No. 4 by 2 P. M. Passed through 12 ft. of over- burden and 10 ft. of sand and gravel by 5 P. M. Fourth day, Finished hole No. 4, which was 28 ft. deep to bed rock. Pulled casing, cut trail and moved to hole No. 5, 300 ft. northeast of hole No. 4, and started new hole by noon. After drilling 17 ft. through overburden an old buried tree was struck, but the drill went through it easily. By 5 P. M. 22 ft. were made in this hole. Fifth day, Finished hole No. 5, 28 ft., and after pulling cas- ing began hole No. 6. Got down 14 ft. in overburden and 9 ft. in gravel by 5 p. M. Sixth day, Finished hole No. 6, going down 9 ft. more to bed rock. Moved outfit across the river and about a mile up the 80 HANDBOOK OF EARTH EXCAVATION river, and at 2:45 started hole No. 7. Made G ft. in overburden and 9 ft. in gravel by 5 P. M. Seventh day, Finished hole No. 7, 29 ft., to bed rock, and moved 50 ft. north and sunk hole No. 8, 22 ft., to rock. Started hole No. 9, 50 ft. north, and made G it. in top soil by 5 P. M. Thus in seven days of drilling 213 ft. were drilled, an average of 30.5 ft. per day. It will be noticed that as the men became accustomed to the work, they improved a little each day. With the Empire drill an auger drill spoon is used that will cut through hard soils, roots and sunken logs and easily pene- trates gravel. It picks up any material and brings it as a core to the surface with a minimum amount of disturbance of the ma- terial as it actually lies in the ground. Water, as a rule, is not used to assist in drilling, so the at ger will pick up the finest particles of gold. If it is desired to use water in drilling it can be done. The casing is pulled by levers with a very simple device. With wages at $1 per day for the men the expenses were about $10 per day, allowing $1 for incidentals, the cost per ft. was about 33 ct. At American wages the cost would have been about 47 ct. per ft. Post Hole Diggers are not true augers, but consist of a scoop or screw which fills itself as forced into the earth; when filled it must be lifted out of the hole and dumped. As this must be repeated for every few inches of hole the process is too slow for use on any but shallow holes. Fig. 21. Post Hole Auger. A useful type of post hole auger is shown in Fig. 21, which is taken from Engineering and Contracting, Oct. 30, 1907. The handle on the small sizes is 4 ft. long, while a 6-ft. handle is used on the larger sizes. For ordinary purposes these lengths are sufficient, but for boring test holes the handle is readily lengthened by attaching additional pipe of the same size as the handle. With a 10-in. auger, holes 35 ft. deep have been bored, while with a 4-in. auger a depth of 75 ft. has been obtained. Where a BORING AND SOUNDING , 81 large number of shallow boles, from which specimens are to be taken are needed, this auger should give excellent results. In the issue of Aug 28, 1907, page 133, the cost of digging post holes for a fence with an auger is given. With wages at $1.50 per 10 hrs., 84 holes being dug with a 6-in. auger, the cost per hole was 1.8 ct., or .7 ct. per lin. ft., which gives a cost of 98 ct. per cu. yd. The style of auger shown in the cut is made of two steel blades, each blade with two cutting edges. The blades interlock at the bottom in the notches made for that purpose, thus holding the dirt, which is released by rapping the flat side of the blade on the ground. The auger is made in ten sizes from 3 in. to 14 in. Boring with Post Hole Diggers on Long Island. In tests for the adlitional water supply of the city of New York, as reported in 1903, some 22 test pits were dug near the South shore of Long Island with 4^-in. and 6-in. post augers, at a total cost of about $14.50, or 60 ct. per hole. The total number of feet was 102 and the cost per ft. therefore amounted to 14 ct. Cost of Post Hole Digger Boring. Emile Low in Engineering News, March 21, 1907, describes the work of making earth auger borings on the New York State Barge Canal. The tools used con- sisted of a light steel cylindrical pod (6 in. in diameter and having a length, including the serrated bottom edge, of 5 in.) composed of 5 saw-shaped teeth 2 in. long. These teeth were bent inward more or less according to the character of material penetrated. The rods were made so that they could be screwed into a standard section of gas pipe 8 ft. long. A suitable handle was provided to grasp the pipe with which the earth auger was turned. The work of boring the holes 6 in. in diameter was ac- complished by turning the ai'ger until the pod was full of earth, then lifting it out and emptying it. In suitable soils holes 16 ft. long were readily bored. In the work described 450 holes were driven an average depth of 13.26 ft. The cost of these borings was 18.3 ct. per ft. Material, muck, sand, clay and gravel. Force employed per day : three laborers at $2.00 ; at times 1 horse and buggy for transportation of men and tools, $2.00. Daily progress-, 3 holes or 40 ft. See my " Handbook of Cost Data " for further information. Cable Drills. In my " Handbook of Rock Excavation," pp. 252-295, methods and costs of using cable drills are given. This method of drilling consists in alternately raising a suing of tools which terminate in a chisel cutting edge and letting them fall. The chopping motion imparted to the cutting tools enables them 82 HANDBOOK OF EARTH EXCAVATION to penetrate through coarse gravel and boulders that could not be passed by the wash boring method without blasting. Diamond Drills are used for prospecting rock rather than earth. Their chief interest from a standpoint of earth exploration is their use to distinguish large boulders from ledge rock. Cost of Test Wells for a Bridge Foundation. P. J. Robinson in Engineering and Contracting, Jan. 5, 1910, gives the following: Test wells were bored to determine the nature of the founda- tions for the piers of a bridge over the American River, Cali- fornia. Stagings were erected from the side of an old bridge and equipment, which consisted of a gasoline hoist and drill machine, was rented from a local well borer, who also supervised the work. Three crews prosecuted the work at the start, ending with one, with wages as follows: Engineman $4.75 Foreman 4.00 Sub-foreman 3.75 Sub-foreman 3.50 Sub-foreman 3.25 Laborers 3.00 Laborers 2.75 Laborers 2.50 Laborers 2.25 A suction sand pump, a design of the local shops, was used through the gravel and cobbles and an earth auger in the clay. The wells were encased with sheet iron and when possible the pipe was pulled and used again. The prices charged for this ma- terial are shown in the cost statement. The wide range in cost of the different sizes is due to the fact that the 14-in. and 12-in. pipe were new, while the 10-in. and 8-in. were second hand. The work was twice interrupted by high water, necessitating the dismantling of the equipment, and thereby adding quite ma- terially to the cost. The cost of this work was as follows: Labor Loading and unloading material, 63% days $ 197.00 Hauling material, 2 days 6.50 Boring well No. 1, 107 days 324.25 Boring well No. 2, 52 days 165.75 Boring well No. 3, 131V 2 days 417.62 Boring well No. 4, 51% days 171.50 Boring well No. 6, 117V 2 days 1 360.00 Erecting staging, 68% days 236.81 Repairing derrick, 2 days 7.00 Making boxes of test well soils, 4 days ..:. 15.00 Rental of well boring apparatus 118.00 $2 019 43 Material Lumber, 9,073 ft. B .M. at $13.83 per M $125.47 Sheet iron casing, 14-in., new, 52 lin. ft. at $2.75 143.00 BORING AND SOUNDING 83 Sheet iron casing, 12-in., new, 172 lin. ft. at $2.25 $387.00 Sheet iron casing, 10-in., second-hand, 49 lin. ft., at $0.60 29.40 Sheet iron casing, 8-in., second-hand, 36 lin. ft. at $0.51 18.36 Store department expense 40.55 2% of labor for use of tools 40.40 784.18 Of the five wells bored, No. 1 and No. 6 were on the bank and Nos. 2, 3 and 4 were located in the channel of the stream. It is noted that well No. 3 was the most expensive to bore, due to the nature of the substance penetrated. . Cost of Test Pitting. The following are costs given in the Engineering and Mining Journal of test pitting in hard clay and hardpan with many .large boulders, where the ground dulls the picks rapidly. Foreman's wages were $3; laborers, $2. Two- inch hardwood plank was used for cribbing when necessary. No superintendence or office expense charged. Depth, Hours, Per Pit feet labor Cost foot 1 17 80 $18.00 $1.06 2 24 140 29.00 1.21 3 7 15 3.50 0.50 4 22 75 16750 0.75 5 23 100 24.00 1.04 6 26 240 48.00 1.84 7 41 270 56.00 1.366 8 46 335 72.50 1.58 9 38 255 64.00 1.70 10 33 240 54.00 - 1.67 11 10 60 12.00 1.20 12 9 100 22.00 2.44 13 9 20 4.00 0.44 14 17 60 12.00 0.70 15 12 55 12.50 1.00 Filling pits Nos. 1, 2, 3, 4 6.00 Filling pits Nos. 5, 6, 7, 8, 9, 10 35.00 Filling pits Nos. 11, 12, 13, 14 7.00 The contract price for sinking a test pit in sandy soil and doing all necessary cribbing, all supplies to be furnished and tools sharpened free of charge, to 20 ft. in depth is $1 per ft.; from 20 to 30 ft., $1.25 per ft. Test Trenches. Trenches used in prospecting a mining prop- erty are described in Engineering and Contracting, June 21, 1911. A trench 60 ft. long, 6 ft. wide and 7 ft. deep was exca- vated by 6 men with picks and shovels in 3.2 days. A staging was then put in, three additional men were hired to re-handle the earth, and the trench was deepened 8 ft. to rock. The cost of excavating 146.7 cu. yd. of earth from the trench was as follows: Six men 3 days at $3 $ 54.00 Nine men 2 days at $3 54.00 84 HANDBOOK OF EARTH EXCAVATION Six round-point long-handled shovels $ 9.75 Three square-point D-handled shovels 4.00 Six 5-lb. drift picks 8.00 Six 36-in. drift pick handles 1.90 172 ft. lumber for staging 3.10 $134.75 Cost per cu. yd., $0.918. Bibliography. "Hand Book of Rock Excavation," H. P. Gil- lette. " Cost Data," H. P. Gillette. " Boring Test Holes with an Auger," Charles Catlett, Trans. Am. Inst. M. E., Vol. 27, 1897. " Methods and Costs of Wash Borings, Great Lakes and Atlantic Ship Canal Survey, 1897-1900," Eng. and Con., Mar. 27, 1907. " Comparison of Cost with Two Light Wash Boring Rigs," A. W. Saunders, Eng. and Con., Dec. 9, 1908. " Cost of Making Test Borings with Wood Augers," A. C. D. Blanchard, Eng. and Con., Aug. 11, 1909. H TtfAM ^0 CHAPTER IV x&mvif i ut 10 at 30 in = 300 in. 30 at 18 in = 540 in. If we assume that the cost of blasting stumps varies as the square of the diameter, the weighted diameter for cost estimating purposes is calculated thus: Total squared diam. 20 at (12 in. X 12 in.) = 2,880 10 at (30 in. X 30 in.) = 9,000 30 at nearly (20 in. X 20 in.) = 11,880 This gives nearly 20 in. as the weighted diameter for cost estimating purposes. Having estimated the number of stumps per acre and their weighted diameter, it is possible to approximate the cost of blasting them out. To this must be added the cost of piling and burning them, which, it is altogether probable, can be reduced to a unit cost per stump of given size that will make accurate estimating possible. Fallen logs may be estimated in cords of wood per acre, and the cost of piling and burning them may then become a matter of quite accurate forecast. In estimating clearing and grubbing, as in estimating any 88 HANDBOOK OF EARTH EXCAVATION other costs, the primary object should be to measure the work in units that are true functions of the cost. By itself the acre of clearing and grubbing is not a satisfactory unit for measuring costs. The thousand ft. board measure is a suitable unit in which to express the cost of felling trees, making them into logs and loading onto cars, wagons, etc. The stump of a given size is the proper unit in which to express the cost of grubbing stumps. The cord or cubic foot of wood, may be a suitable unit in which to express the cost of piling and burning. Other units may be desirable. It is clear that existing cost data on clearing and grubbing are .defective, for the most part, because they are not recorded in proper units. Effect of Method of Excavation on Cost of Grubbing. En- gineering and Contracting, Dec. 25, 1907, gives the following: One of the items of work to be done in grading a railroad is generally the clearing and grubbing of the land. Under some contracts and specifications this work is paid for as one item, under others as two items as clearing and as grubbing, while under other forms of contracts this work is included in that of excavation. The method of paying for clearing by the acre as one item and grubbing as another item is to be commended. In order to do the excavation all the land must be cleared, but in addition to the area used for the cuts and embankments, the entire width of the right of way must be cleared, and overhanging trees and branches must be cut away. On the other hand there is no need of grubbing the area occupied by the embankments, nor that on the right of way not included in the cuts, hence there should be no reason why this area should be included in the payment. Likewise the method of doing the excavation will very materially effect the cost of the grubbing, while it does not play any part in the cost of clearing. When steam shovels are used the grubbing cost is small, as these machines will undermine the stumps, causing them to fall into the pit, where they can be loaded onto the cars by means of chains, attached to the dipper teeth. This work retards the progress made by the shovel, but the cost of grubbing is greatly reduced, and a contractor could afford to bid a low price on the grubbing when done with a steam shovel, if it is not lumped in with the clearing or other work. When grubbing is done in connection with rock excavation, its cost is small as the stumps are shot out with the blasting of the rock, and the only additional expense is to dispose of the stump. This will have to be done by hand and will be work that the contractor will charge for under grubbing. CLEARING AND GRUBBING 89 When grubbing is done for scraper work the stumps and largest roots must be blasted and dug out, and the work is much more expensive than with rock excavation and steam shovel work, although a large railroad plow in loosening the ground will cut and break up many of the roots, so that they do not have to be grubbed. The grubbing for elevating grader excavation must be done much more thoroughly than that for scraper work. The stumps and large roots must not only be grubbed, but all the small bush stubs and roots must also be cut out. This is necessary as the grader plow will not cut these roots, as the pull on the plow is a steady one, unlike that of a breaking plow, which can be run in jerks, while the plowman can shake up the plow, which is a considerable help. In grubbing for a grader it is not ad- visable to blast the stumps, as this makes large deep holes, which, after rains, become full of water and soft, thus causing the trac- tion engine and grader to mire in these holes. For this reason where there are many stumps of 6 in. or more in size a stump puller should be used. For elevating grader work the stump puller does its work much better than blasting, as it will not only pull up the stump, but also all the large roots and many of the small ones. Nor does it leave as large a hole as a blast does. Its work is as economical as blasting, and at times is much cheaper. The small stubs and roots must all be grubbed by hand. To do efficient work of grubbing for a grader, after the large strmps have been pulled, men should be spaced a few feet apart and the entire area gone over, the men working in rows grubbing up everything that may affect the working of the grader. This makes grader grubbing more expensive than that of any other grubbing for ordinary excavation work. Loss of Material Due to Grubbing. Mr. F. W. Harris, in En- gineering Xews, Dec. 17, 1914, says that in timber country 10% of the total excavation can be considered as worthless, as it con- sists of humus, rock, logs, roots, etc., and another 10% should be deducted for quantities lost in blasting stumps. These per- centages should be increased to 15% in each instance where excavation averages less than a 3-ft. cut. Percentages also vary with the locality. In the Bitter Root Mouiitains in Idaho, they would be about 5% ; while on the western slope of the Cascades on the Washington and British Columbia Coast, 15% would not be too high in each case. Estimating Shrinkage Due to Removal of Stumps. F. W. Harris, in Engineering News, Dec. 23, 1915, gives the following data : The method of obtaining an estimate of shrinkage in a timber 00 HANDBOOK OF EARTH EXCAVATION country is as follows: Plot a trial grade line on the profile, seeing that the quantities balance reasonably close. The exca- vation should exceed embankment at least 10%. The profile will give the center cut and fill, and an experienced man can stand on the center line and estimate where the slopes will intersect the ground line. The stumps in each station should be noted and recorded ac- cording to sizes and kinds of stump, also the formation of soil, whether rock, gravel or swamp. It is essential to note the kind of stumps, as some stumps will blow out much easier than others. For instance, a 4-ft. fir stump will leave a smaller hole than a 4-ft. cedar stump. This should be borne in mind merely as it would be a useless refinement to grade the loss of excavation by the kind of stump shot out. In the office the stumps should be listed according to cuts and fills. The following table will apply on the Pacific Northwest Coast for computing loss of excavation by blowing out stumps. Fir, cedar, spruce, hemlock are averaged in the table. 6 to 12 in. ,. 1 cu. yd. each 12 to 24 in 3 cu. yd. each 24 to 36 in 5 cu. yd. each Above 36 in , 10 cu. yd. each In swamps where the growth is spruce, hemlock, cedar, maple, 50% should be added to these quantities, as it requires more dynamite to lift a stump of given size, owing to the decreased resistance of the swamp soils. To get shrinkage, say between Sta. 20 and 30, this would average a 4-ft. cut on the center line for the entire distance. Assuming the record shows the soil to be clay and hardpan, the list of stumps for this section would total 65, divided as follows: 6 to 12 in 20 20 cu. yd. 12 to 24 in 20 60 cu. yd. 24 to 36 in 20 100 cu. yd. Above 36 in 5 50 cu. yd. 65 230 cu. yd. In this cut the grade line would have to be lower to give the additional 230 cu. yd. lost in blasting. As the same condition, however, is assumed to exist in the adjacent fill, the grade line will give a correct balance. The grubbing clause should be revised to inchide the following: All stumps and roots on the right-of-way to be grubbed will be paid for according to the list of sizes shown on the schedule of quantities. Stumps 6 to 24 in. will be measured 4 ft. above the ground ; stumps over 24 in. diameter will be measured at the butt log or on top of stump. CLEARING AND GRUBBING 91 Clearing and Grubbing Methods. Trees are cut down with axes and saws, cut up into saw logs, ' poles, ties or cord wood arid removed. The remaining debris is piled and burned. Stumps can be dug out by hand, burned in place, pulled or blasted. Digging Out Stumps is a costly operation. It is sometimes unavoidable but whenever possible some other means of removal should be sought. Burning in Place, while often economical, is too slow a process for general use. It has the advantage of making a complete dis- posal of the stump at once. On very large stumps such as are encountered in the Pacific Northwest the saving in cost of dis- posal may justify the use of this method. Blasting is by far the most satisfactory method of grubbing stumps prior to excavation, and if care is taken not to use too much explosive it is equally suitable for removing stumps from the base of embankments. It is a convenient method requiring no extra plant and no special skill beyond that readily acquired by the average foreman. Amount of Dynamite Used in Stump Blasting. The following table taken from records of blasting in Minnesota, Pennsylvania, Oregon, Kentucky, Michigan and Florida is given by Mr. J. R. Mattern in a bulletin on clearing land of stumps, prepared for The Institute of Makers of Explosives. The stumps were blown out effectively and successfully and the figures should serve as a guide. The grades of dynamite used are not given. TABLE AMOUNT OF DYNAMITE USED IN SUCCESSFUL BLASTING Dead Pine Stumps Diameter and soil 10 in., Clay 12 Sand 12 Loam 12 Clay 14 Clay 16 Clay 18 Sand 18 Loam 18 Clay 20 Sand 20 Clay 24 Loam 24 Sand 24 Loam 24 Clay 36 Sand 36 Loam 36 Clay 40 Clay 48 Sand 48 Loam 48 Clay 60 Clay Sticks of 1% in. dynamite or powder 1 1 1 P i* I 10 8% 92 HANDBOOK OF EARTH EXCAVATION Green Pine Stumps Diameter and soil Sticks of 1^4 in. dynamite or powder 15 in., Loam 4 24 " Sand 10 Dead Oak Stumps 8 in., Sand V/ z 12 " Sand 2 12 " Loam 1^ 15 " Loam li& 16 " Clay 1% 18 " Loam 3 20 " Loam 3*& 24 " Clay 3 26 " Clay 2 27 " Sand 5 27 ' Loam 4^ 30 ' Clay 4% 30 " Sand 6 34 Clay 4^ 38 ' Clay 5% Green Oak Stumps 16 in., Clay , na/| 3 Dead Fir Stumps 30 in., Loam 10 36 " Clay 12 72 "' cffv" 1 ' ,i(<- 'to ''.l,it[ >. OK () t i-u'*f.rmrp- .*IK;> til ./{-jjiDju CHAPTER V LOOSENING AND SHOVELING EARTH Methods of Loosening the Soil. There are three methods in common use for loosening earth: (1) picking, (2) plowing, and (3) by explosives. Many materials are loosened and loaded at the same time with the hand shovel, but it is almost invariably cheaper to pick or plow or otherwise thoroughly loosen any kind of earth except sand, before shoveling. Clays, when wet and tenacious, may be effectively cut with spades. Cost of Picking. The pick is ordinarily not as economical as the plow, but it must be used in digging trenches and in other confined places. 'Trautwine gives the average output per man- hour as follows; wages assumed at 20 ct. per hr. Material Cu. yd. per hr. Per cu. yd. Stiff clay or cemented gravel 1.4 $0.146 Strong heavy soils 2.5 .08 Loam 4 .08 Light sandy soil 6 .03 Pure sand 20 .01 M. Ancelin states that a man with a pick would loosen 1.6 to 2.3 cu. yd. of earth, 0.7 to 1.1 cu. yd. of gravel, and 0.9 cu. yd. of hard pan per hour. In loading from a high bank of hard sand into cars, it required one pick or bar man to each pair of shovelmen. Each pair of shovelmen sent out 30 loaded cars, equivalent to 30 cu. yd. per hr. It must be remembered, however, that this material while hard, was located in a high bank, and much of it was undermined or barred down, and broke by force of the fall, thus requiring very little actual picking. High clay banks are sometimes loosened by powder, but more often by " undermining " and " falling." A narrow cut is dug into the base of a bank that is 7 to 8 ft. high, and a line of wedges is driven on top, 1 or 2 ft. from the edge; thus wedging off pieces weighing many tons, which break in falling. Patton in " Civil Engineering " says that throwing horizontally with a shovel is limited to about 12 ft., or about 6 ft. vertically. Comparison of Pick and Mattock. In trimming ground, Engi- neering and Contracting, Jan. 15, 1908. states that the mattock is much better adapted than the pick. This is so of parking work, as in trimming there is seldom more than an inch or two of earth to be dug and the narrow pick will not cut off as much earth at each stroke as the broader blade of the mattock. In railroad cuts, the pulling down and dressing up of slopes is done better by mattocks than by picks. Likewise in cellar and founda- tion work, where it is necessary to dress down a perpendicular 94 LOOSENING AND SHOVELING EARTH 95 side of a bank to neat dimensions and lines, the inattock does better and more economical work than a pick. Thus for nearly all cases of trimming and dressing the mattock should be the tool used. For digging, as a rule, the pick should be given the preference. At one blow with a pick a large wedge shaped piece of earth can be loosened from a bank, when the face of the wedge is free, while with a mattock a single blow will not loosen as large an amount of earth, the piece being a truncated wedge, of seldom more than half the altitude of the wedge the pick will loosen, and only about two-thirds of the base. This should always be remem- bered, as the most important misuse of the mattock is to use it in open cut work for digging. The mattock can be used to better advantage than a pick for digging some few materials. This is so of very plastic clays. A pick will make but little more than a hole in material of this kind, and when it is used as a lever, this hole will simply be enlarged, but with a mattock small pieces can be pried out and large pieces can be cut out by the cutting blade. A more eco- nomical and satisfactory way of digging this kind of material than with either the mattock or the pick is with a spade. One of the editors of this paper increased the output of a gang of men nearly 30% in handling such material in a railroad cut some years ago by substituting spades for mattocks and shovels. All the work was done with one tool, and the loosening or digging was done better and cheaper with the spade. In swampy and marshy ground the mattock is superior to the pick for digging. This is due to the fact that there are generally roots in such ground, and also because the material is generally clay of more or less plasticity. The comments that have been made regarding grubbing with a mattock show that it is the tool for digging and loosening whatever roots are encountered. It is also true that turf and peat are dug better with a mattock than with a pick. In digging ditches and trenches a mattock is often needed until the trench is a foot or more deep, as roots are encountered and sometimes old logs and debris, but as soon as this kind of ma- terial is gotten rid of, only picks should 'be used. The cost is greatly increased by using mattocks. The sides of trenches can be dressed well with a pick, so that sheeting can be put in place. In open ditches the pick should be used for digging, but when a permanent slope is to be put on the ditch a mattock should be used. The mattock is essentially a grubbing and dressing tool, and is only adapted to economical digging in a few special materials. 96 HANDBOOK OF EARTH EXCAVATION It may be termed a misuse of the tool to make it do digging in ordinary earth. For earth work a supply of mattocks and picks should always be provided, so that as occasions arise for the use of each they will be on hand and money will not be wasted in making a tool do work for which it is not adapted. . Cost of Picking and Shoveling. The cost of loosening with a pick, and shoveling into wagons when wages are 20 ct. per hr. is as follows: Kinds of Earth Cu. yd. per hr. Per cu. yd. Easy earth, light sand or loam 1.25 $0.16 Average earth 1.00 0.20 Tough clay 0.75 0.27 . Hard sand 0.375 0.53 Shoveling. By vigorous exertion a man may shovel 1 cu. yd. ("place measure") of light loose earth into a wagon in 12 or even 10 min., or at the rate of 50 or 60 cu. yd. in a 10-hr, day, using the ordinary round-pointed shovel. A man can sprint 100 yd. in 10 sec. or at the rate of 20 miles an hour, yet no one would expect a continuance of the performance all day long. Short-time observations, where a man is working vigorously, should therefore not be made the basis of an estimate of average cost, as is not infrequently done. Trautwine speaks of the " lost time " of shovelers as being ordinarily about 4 hr. out of 10. The expression is misleading, for time spent in rests between the arrival of teams is not time lost, provided the foreman insists upon vigorous exertion while actually working. A man may shovel only 20 min. out of an hour, yet accomplish exactly as much in a day as another man shoveling steadily. Bear in mind that men need not be kept steadily busy, provided that when they do work they make up for the time "lost" in resting; and the same is true of horses. In this connection it is very interesting to note that if rea- soned out " theoretically," as machine work frequently is by inventors and over-sanguine manufacturers, the output of a plow should be many times what it actually is, using " conservative figures " thus: The ordinary plow cuts a furrow 6 in. deep by 12 in. wide, so that a team traveling at the very slow speed of li& miles an hr. (less than half its ordinary walking gait) would loosen 110 cu. yd. an hr., while if it walked right along at its usual gait the amount would be 220 cu. yd. loosened per hr. ! There has been too much of such " theory " used in estimating the cost of earth work. It may be said that, roughly speaking, about 175 shovelfuls of earth thrown into a wagon box form 1 cu. yd. If we assume average earth to weigh 100 Ib. per cu. ft., we find that an LOOSENING AND SHOVELING EARTH 97 TABLE OF COST OF DIGGING AND SHOVELING (Wages 20ct. per hr.) Cu. yd. per Ct. per man-hr. cu. yd. Mud into wheelbarrows (1) 0.8 25.3 Gravel into wheelbarrows (1) : . . . 1.7-2.7 9.3 Earth into wheelbarrows (1) 1.6-4.8 6.7 Earth into wheelbarrows average (1) 2.2 9.3 Earth into wheelbarrows (2) (10 miles Erie Canal)... 2.8 7.0 Earth (all kinds) into wagons (3) 2.1 10.0 Earth (all kinds) into wagons (4) 2.0 10.0 Sand into cars from high face (5; '1.0,000 cu. yds. place measure) 1.8 11.0 Gravelly soil into wagons after plowing (5) (20,000 cu. yds. in embankment) 1.3 15.3 Iowa soil (6) 1.5-2.0 11.3 Iowa soil (A rush job) (6) 2.8 7.1 Clay and gravel into carts (7) 1.0 20.0 Loam into carts (7) 1.2 16.7 Sandy earth into carts (7) 1.4 14.3 Lease sand into carts (8) 2.0 10.0 Clay, tenacious, excavated with spade (8) (Spaded out and handled with forks 1.25 16.0 Loosened hardpan into low dump cars (9) 1.5 13.3 Loosened average earth into dump cars (9) 1.75 11.4 Heavy black clay, wet, cast 5 to 10 ft. (10) 0.33 60.0 Loading hardpan into carts after picking (10) (Picking done at rate of 0.6 cu. yds. per man hr. Not enough pick men) 0.5 40.0 Excavating sandy gravel and stiff clay; wet (10) .... 0.33 60.0 Excavating dry sandy clay (10) (Earth rehandled 3 and 4 times. Inefficient foreman) 0.2 100.0 Shoveling quicksand into buckets (11) (Coffer dam excavation, 2 men to a bucket) 0.21 95.2 Authorities (1) M. Ancelin; (2) Gillespie; (3) Cole: (4) D. K. Clark; (5) Gillette; (6) J. M. Brown; (7) E. Morris; (8) G. A. Parker; (9) Lyons; (10) Engineering and Contracting; (11) Eng. Record. average shovelful contains approximately 15.5 Ib. At a good steady gait, 7 shovelfuls are loaded per min. where the vertical lift is about 5 ft. In casting for a vertical lift of 10 ft., how- ever, only about 5 shovelfuls are handled per min. In casting earth horizontally, we may count on 9 shovelfuls per min. for a 5 ft. horizontal cast, and about half as many for an 18 or 20 ft. horizontal cast. With wages at 20 ct. per hr., it will cost about 6.67 ct. to carry a cu. yd. 10 ft. in shovels. The amount of earth that a man will handle per lir. with a shovel varies not only with the character of the soil, but with the method of attack. If a man is shoveling ' from a face of earth over a foot high, one that he can readily undermine with a pick* for example, he can load into wagons 1.8 cu. yd. an hr. on an average; while if he is shoveling plowed soil, where he must use more time to force the shovel down into the soil, his output will be about 1.4 cu. yd. per hr. If he is shoveling loose earth ofT boards upon which it has been dumped, his outpvit is about 2.5 cu. yd. per hr. 98 HANDBOOK OF EARTH EXCAVATION At a meeting of the Connecticut Civil Engineers' and Surveyors' Association, Jan. 8, 1901, Mr. G. A. Parker, Supt. Keney Park, Hartford, Conn., gave the following as the results of his experi- ence: The bank was loose sand requiring neither picking nor plow- ing. Material was shoveled into two-horse carts holding 1 cu. yd. It is not stated whether the measurement was of loose sand in carts or packed sand in bank, but apparently measure- ment was made in carts. It required 150 shovelfuls to make a cu. yd., and a man by shoveling 25 sec., then resting 25 sec., would average 5 shovelfuls loaded in 50 sec., or 22.8 cu. yd. in 10 hr., after deducting 5% for waste time. Each man counted his shovelfuls, and was allowed to cast only 5 shovelfuls before the team moved on. There were 15 shovelers in a gang and two gangs in the pit. Mr. Parker claims that the results justify his statement that this is the best known method of working men, as it gives them needed rests, and keeps their minds active. It may be observed that it might not work so well where soil is tough, and that just as high outputs have been obtained by the common methods where sand was loaded. Size of Hand Shovels. This is an important subject and the one which has received almost no attention from contractors and engineers. It seems to be the custom, sanctioned by long usage, to use a shovel of the size known as No. 2 or No. 3. From data presented by Mr. C. W. Hartley, in Engineering and Contracting, Mar. 31, 1915, Mr. Hartley finds that a No. 2 shovel holds but 13 Ib. of earth and 14.5 Ib. of sand; and a No. 3 shovel, 15.5 Ib. of earth and 17 Ib. of sand. Observations of Mr. F. W. Taylor show that the proper sized shovel for the average man contains 21 Ib., and, on that basis, Mr. C. W. Hartley made some inter- esting experiments, working with shovels as follows: In a gang of 38 men working in a trench, with shovels fur- nished by themselves, it was found that 92% were using the smallest sized shovel on the market, No. 2, while the remainder were using the next size larger, No. 3. These shovels are in- capable of holding the amount of material that should consti- tute a shovelful. It was further observed that 50% of these men were using shovels which were worn down at the bottom, within 3 in. of the point, or until only half of the original blade re- mained. The loss for each shovel was estimated. By careful time observations it was demonstrated that the men using the worn shovels worked no faster than those using the good; further that men will shovel at approximately the same speed, whether they are working with a No. 2 shovel or a No. 4, and, as a gen- LOOSENING AND SHOVELING EARTH 99 era! rule, will fill the blade full whenever possible to do so. This being the case, it is self-evident that the use of small or worn shovels will entail the handling of less material. A No. 2 shovel in good condition was found after many trials to hold, as an average load, 13 lb., the material being common loam, loose and dry. The same size shovel, worn down such as were used by half of this gang of 38 men, were found to hold but 7 lb. of earth or loam, which is, as will be noticed, only one-third of the amount Taylor has shown to be productive of the greatest shoveling efficiency. Now let v.a assume that these 38 men were paid at the rate of 20 ct. per hr., or $1.80 per day, and that 13 lb. represents the unit basis from which their output is figured. Fifty per cent, or 19 of the men were using worn shovels, and were doing but %3 of the amount of work done by the remainder. Figured in terms of money, this would give a loss of 82 ct. per day per man, or $15.77 per day for the entire gang, or 41.5 ct. per day for each shoveler in the gang of 38 men. It is easily seen how these fig- ures would be increased if figured with 21 lb. as the unit. For instance, if a man is shoveling with a shovel holding but 7 lb. of earth, when he might use one holding 21 lb., he is therefore performing but one-third of the amount of work that might be accomplished by him, were he provided with the proper tool. If he is a $1.80 man, engaged in shoveling all day, this means a loss to his employer of $1.20 per day. These same data were obtained for shovels of other sizes, No. 3, No. 4 and No. 5, and from these foregoing described experi- ences Mr. Hartley determined to use No. 4 shovels. It has also been the custom, particularly in eastern states, for the contractor to allow the laborers to furnish their own shovels. This is a grave mistake, as laborers are naturally inclined to use the smallest sized shovel, and each will furnish a shovel of but one shape; whereas it is generally economical to use a shovel of different shape for each kind of work, and of different size for each kind of material. The argument against furnishing shovels for the men has been that many are lost or stolen. Mr. Hartley presents a report showing the number of shovels in use, and those lost and worn out during the season starting Apr. 15, 1914, and ending Nov. 10, 1914. In this season of 168 working days, 756 shovels were furnished the men and 353 shovels were used up, an average of 2.1 per day. These shovels were of two different grades, costing $8.60 and $5.25 per dozen. Assuming that each shovel cost 72 ct. apiece, or at the rate of $8.60 per dozen, the cost for supplying No. 4 shovels for laborers was $1.51 per day. The average number of laborers at work daily was 178, and the 100 ' HANDBOOK OF EARTH EXCAVATION cost of the shovels was less than 1 ct. per man per day. Of the 353 shovels used up, 308 were worn out, and 45 were unaccounted for, being lost, stolen or broken. It would seem that this small percentage of 12.7 unaccounted for would tend to refute the v ar- gument that many shovels are lost and stolen. From the foregoing the reader must not infer that a No. 4 or No. 5 shovel is best for all work. On the contrary, the size and shape of the shovel must be suited to the hardness and tenacity of the soil, as well as its weight and other characteristics; for example, in tough soils a round-pointed shovel that will easily penetrate must be used, while for handling loose earth or in shoveling sand, unless it is to be cast some distance, it is folly to permit the shovelers to use any but large, square-pointed scoops. With a large square-pointed scoop, a strong man can, for a short time, load sand into a wheel-barrow at the marvelous rate of 5 min. per cu. yd. On any work where various kinds of material are handled, several sizes and shapes of shovels should be supplied. This is contrary to the usual practice as evi- denced by an interesting example noted in Engineering and Con- tracting, Apr. 7, 1915. At a point where steam railway tracks were being elevated over a street, carrying a double track trolley line, three different gangs of laborers, representing three different interests, were engaged in excavating hard yellow clay with hand tools. The steam railway gang excavated for a bridge abutment, the water pipe extension gang excavated for the lowering of a large main, and the street railway gang excavated for track de- pression. Each gang used the ordinary square-pointed shovel, commonly used in mixing concrete by hand. It was not at all uncommon for a laborer to work diligently for at least a minute in sinking his shovel into the clay the full length of the blade. To do this, much "pumping" of the shovel handle and much pushing with the foot was necessary. This black clay was the same as that lying under the black top soil of the Illinois prairie. In digging ditches used for tile draining, farmers uniformly use ' a long narrow bladed spade, locally known as a " tiling spade." This spade is referred to in some localities as a " sharp shooter." In the soil mentioned, one or two thrusts by the foot will stick it in to its full length. Spades of this type should have been used on the excavating operations above mentioned. Scientific Management in Trenching. Engineering and Con- tracting, Nov. 29, 1911, gives the following: The laying of mains and services for a gas works offered the most prolific field of investigation to begin with, since more than 400 men were engaged in this kind of work. With the aid of a stop watch and note book the following data were gathered: LOOSENING AND SHOVELING AIITO K)l Laborers digging 9 ft. sections of 3.23 cu. yd. each. " Laborer Min. per cu. yd. No. 1 75.8 | > lf ' m 83'8 The time for removing this dirt was much too slow, and this for the following reasons: 1. The working capacity of the different men varies greatly due to lack of experience, old age, and a slow natural gait ac- quired by years of such work. 2. Good men, natural-born workers, and capable of much work, are slowed clown or work at the pace set by the men next to them. 3. Men will " soldier " at every opportunity. They will work at a reasonable gait while the foreman stands over them and watches them, but just as soon as he turns his back and leaves the gang, the men will " soldier." The foreman purposely picks a crew of mixed nationalities so as to avoid " soldiering " and waiting for each other as much as possible. Two days later, after spending most of the time with the gang, 14 10-ft. sections were laid off, and the men timed on each section, with the results given below: Laborer Time per cu. yd. No. 1 55.1 2 69.3 3 66.5 4 42 2 5 -'bnuT > I9J&OSM 'to an<>U 7 625 8 62.5 9 62.5 10 63.7 11 63.7 12 72.2 13 75.0 14 ,.ft{jT 71.0 The average time waa 60 min. per cu. yd.. The two men dig- ging sections 4 and 5 are good men and work fast. They could easily earn $2.50 per day on the basis of $2 for the average man. All the men knew they were being watched closely, and worked more steadily than they otherwise would. Of course, there is always some variation in soil, and temperature conditions have a good deal to do with the manner in which the men work. It grew hotter in the afternoon, and the men naturally weakened a little. 102 HANDBOOK OF EARTH EXCAVATION Similar observations were made with another gang working on the laying of a 4-in. main on Cameron Ave., north of Wood- land. Number of hr. digging: 84. Yd. of dirt removed: 86.85 = .967 hr. or 58 min. per yd. as the average of 17 men digging. When I came to this job I told the foreman that I was doing some inspecting for the Street Department. When he saw me taking notes in my book and frequently looking at my watch, he began to push the men along, muttering to them in their own language, most of them being Polish. He complained about the short run jobs, and said it was difficult to know how to place his men. The soil here is softer than that on Jefferson Ave., but wet and heavier below the first foot or two. In two different places the banks caved in in the same half block, while nothing like this happened on Jefferson Ave. in about four blocks or more. Ratio of Time Required to Dig and Throw One Shovelful of Dirt to the Time Required to Backfill One Shovel of Dirt. Allowing for variation in soil of section by considering the section as com- posed of % soft soil and % harder soil, and multiplying observed times by this ratio: On Jefferson Avenue, 1 ft. below surface: Mean time per shovel 11.5 sec. Do., 3 ft. below surface: Mean time per shovel 16.41 sec. 11.5 X % = 3.83 16.41 X % = 10.95 14.78 sec. per shovel Mean of 51 other observations taken at random, 13 sec. per shovel. Average of the two (about), 14 sec.: Time per shovel on backfilling: 8-in. main gang (mean of 180 observations), 5 sec. 4-in. main gang (mean of 190 observations), 4.8 sec. Time required to dig 14 2.8 Time required to backfill 5 or a yard of dirt should be thrown back in .357 times required to dig it. Taking the following as the average cross- section : One cu. yd.= 33.4 lin. in. or .928 lin. yd. Total time required to dig and backfill .928 yd. of ditch of the above section = 59 min. dig- ging + 16.5 min. backfilling, or 75.5 min. per cu. yd. Digging of the Average Man Under Close Supervision. Soil rather hard, and ditch located about 5 ft. from row of trees. Digging in the morning: LOOSENING AND SHOVELING EARTH 103 (1) Average time per yd. for good men, 47.3 min. (2) Average time per yd. for average men, 57.4 min. (3) Average time per yd. for good men with bonus, 38.3 min. (4) Average time per yd. for good men without bonus, 59.3 min. (No. 1 is the average of No. 3 and No. 4.) Amount of work done by bonus men was 1 :51 times work done by average man. This is equivalent to $3.03 on a basis of $2 per day. The bonus allowed was three hours' overtime, making the day's pay $2.60 instead of $2. On the basis of 60 min. for the average man and 40 min. per yd. for the bonus man, the men would be doing an excellent day's work. Even allowing this bonus for work at the rate of 45 min. per yd. ($2.66 on the basis of $2) would pay because of the influence of the good men on the other men. The Design of Shovels. Fig. 1, given in Engineering and Con- tracting, Aug. 18, 1909, shows a method of testing shovels. A cord was suspended from a spring scale to the handle at the point Fig. 1. Sketch Showing Method of Determining Efficiency of Shovels. 104 HANDBOOK OF EARTH EXCAVATION the workman usually grasps in lifting. The distance from the end of the handle to the point of suspension was the same in all cases. This then brought the hand some distance from the bowl with long handles and very close to the bowl with short handles. The bowls were loaded and the spring scale showed that the shorter the handle the greater the load on the bowl with a certain weight read on the dial which meant the shorter the handle the greater the load with the same effort. The inclination of the handle to the bowl a]so cut considerable figure. The experi- ments would indicate that for lifting and turning, the shovel to use should have a rather short handle with a pretty large angle from the line of the bowl. Such a shovel should be good for handling loose coal, broken stone, gravel and for concrete mixing. The bowl is a trifle larger than the ordinary No. 2 shovel, is flat and is slightly concave on the lower side for half its length. The object of this is said to be to furnish stiffness when occasional spading is done, to furnish an angle to make the front edge self sharpening and to prevent the suction so often experienced in handling soggy earth. Types of Shovels. Of the many types of shovels manufactured the following are designed for use on earthwork. Prices given are those in effect prior to the war. Nursery Spades cost $11 per doz. Ditching Spades an'd Con- cave Drain Spades 14 to 18 in. long, cost $9 per doz. Post Spades cost $12 per doz. and Marl Gouges, 10 to 14 in. long, cost $5 to $7 per doz. Hand Shovels. Net prices for standard railroad contractors' and mining shovels, at Chicago, in quantities, are as follows with prices for four grades: (1) Extra grade made of best crucible steel, finely finished with best white ash handles; (2) first grade shovels, also made of crucible steel, and grades (3) and ( 4 ) made of open hearth steel. The net prices in Chicago on these four grades are as follows: PRICES AND SIZES ON HAND SHOVELS 21 S gh5 S S 02 W 43 2 9% 11% $8.91 $7.83 $6.48 $5.70 3 9% 12% 9.18 8.10 4 lO 1 /^ 12% 9.45 8.37 The above prices are for black finish; for polished add 50 ct. per doz. Shovels with square or round points, " D " or long LOOSENING AND SHOVELING EARTH 105 Fig. 2. Nursery Spade. c Fig. 3. Ditching Spade. hmio/l <>'lfrrT{ ^noJ Fig. 4. Concave Drain Spade. IE u Fig. 5. Post Spade. Fig: 6. Marl Gouge. Fig. 7. D Handle Round Point Shovel. ihitt }*tfO i'*i$i \jiti 'ivvi* Fig. 8. D Handle Square Point Shovel. 106 HANDBOOK OF EARTH EXCAVATION handles are all the same price. The size No. 2 is the one com- monly used. For sewer or brick shovels made in No. 2 size, but having a shorter and heavier blade for clay and other heavier material, net prices are as follows: Each Per Doz. Extra grade Second grade $1.00 Fig. 9. Long Handle Round Point Shovel. Fig. 10 shows a scoop for breaking down from the top of cars and getting to the bottom when a square point scoop will not work. Fig. 10. Diamond Point Scoop. Fig. 11. Telegraph Shovel and Spoon. Cost Data on Hand Excavation. Mr. John F. Ely, in Engi- neering and Contracting, June 19, 1907, gives some observations on the cost of excavating earth. The following examples were observed. LOOSENING AND SHOVELING EARTH 107 1. Six men excavated a square hole containing 15 cu. yd. in 6 hr., or at the rate of 0.4 cu. yd. per man hr. 2. A gang averaging 4.5 men dug a trench 3.5 by 5 ft. deep, 370 cu. yd., in 25 hr., or at the rate of 0.42 cu. yd. per man hr. 3. A gang excavated for a cellar 5 ft. deep, 1,029 cu. yd., 5,840 labor hr., or at the rate of 0.69 cu. yd. per man hr. 4. Four men excavated for a man-hole, 79 cu. yd. in 60 hr., or at the rate of 0.33 cu. yd. per man hr. 5. Ten men excavated for a sewer 111 cu. yd. in 36 hr., or at the rate of 0.30 cu. yd. per man hr. 6. A gang excavated a trench, 8 ft. wide by 4 ft. deep, contain- ing 193 cu. yd. in 418 labor hr., or at the rate of 0.47 cu. yd. per man hr. 7. A gang excavated for a cellar containing 1,603 cu. yd. in 6,400 labor hr., or at the rate of 47 cu. yd. per man hr. 8. A gang excavated for a sewer trench, 3 ft. wide by 5 ft. deep, containing 137 cu. yd. in 259 labor hr., or at the rate of 0.53 cu. yd. per man hr. Total 11,415 labor hr., 26,538 cu. yd., or at the rate of 0.57 cu. yd. per man hr. In the third case, the earth was partially loosened by plowing, and partly by pick, and shoveled directly onto wagons. In the fourth and fifth cases the small amount was due to the depth and narrowness of the excavation, some shoring being necessary, and a part of the earth being hauled twice. Cost of Handing Ore. Mr. H. E. Scott, in the Journal of the Worcester Polytechnic Institute, states that in unloading ore at the Lake Erie dock the shovelers were paid by the ton, and that the following records have been made: The prices paid were 13 ct. per ton on straight work, and a maximum of 18 ct. per ton for cleaning up, after 80% of the cargo had been removed by automatic machines. Men working at the 18 ct. rate have earned as high as $12 per day of 10 hr., which means 6.67 tons of ore were shoveled in one hour. Work- ing at the 13 ct. rate with eight men in a hold, shoveling into one ton bucket, each man can handle 5 to 6 tons of ore per hr. Loosening and Shoveling Sticky Clay. Engineering News, Sept. 27, 1890, contains an interesting note on 'the methods used for loosening and shoveling clay in the St. Clair Tunnel, Chi- cago. The clay was known to be soft, and no difficulty was an- ticipated in digging it, but in this very soft tenacious clay lay the root of the trouble. Had the clay been stiff and dry, it could have been dug with pick; but it was permeated with water, and in tenacity it is said to have borne some resemblance to India rubber. An ordinary shovel was bent out of shape prying into the 108 HANDBOOK OF EARTH EXCAVATION sticky mass, and even spades were soon doubled up. The spade illustrated in Fig. 12 was tried, but the progress made with this tool, however, was discouragingly slow, for the clay had to be pried out in chunks. On the average, one gang of 26 men could dig out about enough in 8 hr. to advance the shield 2 ft. ; a creditable enough advance perhaps, and yet aggravatingly slow. Before the tunnel had progressed very far, a carpenter, or joiner, secured employment as a laborer in the excavating gang. He had never been accustomed to working with a shovel or spade, but with the draw-knife. The next time he reported for work he carried an arch-shaped draw-knife, made of a piece of heavy band iron, bent to a half circle about 6 in. across, with eyes at each end in which wooden handles were stuck. The lower side of the Fig. 12. Spade and Scraper Used in Tunneling in Clay. band was brought to a cutting edge. With this novel styl? of draw-knife he went to work and was able to shave the clay down twice as fast as it could be chopped out with the spaJe. All the men were soon supplied with the new tool, and from that time forward the rate of progress of the excavation was materially increased. In connection with work in this kind of material, it is well to note that in ordinary Chicago clay, a man with a spade should excavate 10 cu. yd. per day of 8 hr. This kind of clay is best rehandled with forks after it has been spaded out of place. In shoveling stiff clay with shovels, the rate of progres can be in- creased by dipping the shovel in water between each shovelful. In shoveling sticky mud, if a few holes are drilled in the blade of the shovel so as to allow air to penetrate between the mud LOOSENING AND SHOVELING EARTH 109 ^ and the shovel blade, the suction will be reduced, and the mud will slip more easily off the bowl. The Cost of Digging a Cess Pool. Engineering and Contracting, Oct. 28, 1908, gives the following: The hole was dug on Long Island in a clay material with an occasional boulder. The material was stiff enough to stand up without shoring. The hole was 8 ft. in diameter and 24 ft. deep. For two days two men did the work, but, when a bucket had to be used, another man was added to the force. A three-legged derrick, with a crank on it, was used to hoist the bucket of earth. The excavation was made entirely with picks and shovels. There were 1,305 cu. ft. of material excavated, or about 48 cu. yd. A 10-hr, day was worked. The cost of the work was as follows: 2 men 2 days at $1.50 $ 6.00 3 men 5 days at 1.50 22.60 Total $28.50 This gives a cost of 60 ct. per cu. yd. for excavating and hoist- ing the material and dumping it on the ground by the side of the hole. This cost is quite reasonable for this sort of work. Cost of Picking and Shoveling Hardpan. (Engineering and Contracting, Dec. 16, 1908.) In a clay cut on some railroad work in Ontario Co., Ontario, Canada, some cemented gravel or hardpan was encountered. The bed of gravel lay along the bottom of the cut, and the part to be excavated was from 0.8 ft. to 4 ft. in depth. The cemented gravel was so hard that a pick, handled by an experienced man, would only enter it about 1^ in., but the extent of the work was so small that the contractor did not feel justified in purchasing a pick pointed or rooter plow. To excavate this hardpan with picks and shovels required 4 pickers to 5 shovelers, and 1 man was used on the dump. Wages were 15 ct. per hr. The extreme haul on the excavated material was 1,000 ft. . At first 4 carts were used but the hauling was finished with 6 carts, at 18 ct. per hr. In all 500 cu. yd. of hardpan were moved at the following cost per cu. yd.: Shoveling $0.304 Loosening 0.245 Dumping 0.030 Hauling 0.195 Total per cu. yd $0.744 This is a high cost, although the allowance of 18 ct. for carts per hr. is small. The pickers loosened about 6 cu. yd. per day of 10 hr., while the shovelers shoveled 5 cu. yd. per day per man. This 110 HANDBOOK OF EARTH EXCAVATION is a low record for shoveling, but as the layer of gravel was thin it was no doubt difficult to keep enough muck loosened to allow the men to get a good shovelful as they worked. Although the cost of loosening is nearly one-third of the total cost, yet the cost per cu. yd. may have been reduced by using some extra pickers, thus allowing the shovel men to make a greater output. A Rating Table for Excavating with Pick and Shovel. Mr. L. T. Sherman, in Engineering and Contracting, May 27, 1914, pre- sented a novel method of rating the probable amount of excava- tion that can be done with pick and shovel in various materials. This article follows in full: The accompanying diagram and tables represent the amount of excavation of various materials which will be performed in a 10-hr, day by the average laborer working under good super- vision. In making this compilation the writer has compared a large number of data from many sources with figures obtained in his own experience on construction. As might be expected there is wide divergence in such published data. The curves in the diagram are based on a rational relation of one class of material to another as regards the amount of work or power required in picking or shovel cutting and the power re- quired in casting up materials of different weights. The output of excavation is proportional to the amount of power or work required to move a cubic yard of the material. Let the amount of work or power to cut into and fill the shovel with sand be called unity. Then for other materials the relative power to cut out and place on the shovel will from experience be as in Table I. TABLE I POWER TO PICK, LOOSEN AND CUT ONTO SHOVEL Sand P 1.0 Gravel, loose P = 1.5 Earth, medium P = 2.0 Clay, light P = 3.0 Clay, dry, hard P = 4.5 Clay, wet, heavy P = 5.0 Hardpan P = 6.0 The work or power to lift or cast up the material after the shovel is filled is proportional to the weight of material and height cast or, which is the same, the depth of cut. Then if W is the weight, the relative power to cast up material to different heights H will be as follows: Sand W H where W = 1.0 Gravel W H where W = 1.0 Earth, medium W H where W = 0.8 Clay, light W -H where W = 1.1 Clay, dry W H where W = 1.1 Clay, wet W H where W = 1.3 Hardpan W H where W = 1.12 LOOSENING AND SHOVELING EARTH 111 The total power to shovel and cast any material is P -f W H. The output is inversely proportional to the power or work re- quired. The output of any material by hand excavation in cu. yd. per man per 10 hr. is 30 Cubic yd. = P + .3 W H The constants 30 and .3 are empirical, and like the relative values of P have been selected to correspond with the best data available on excavation of various materials at different depths of cut. The curves in the diagram Fig. 13 are platted according to the above formula with coefficients P and W as previously noted. The letters represent observations from various published state- ments and are not equally reliable or comparable. The curves do not attempt to average the data but correspond with the writer's experience and some of the most definite of the published data. Table II shows the number of cu. yd. an average laborer should excavate and cast out, at various depths in 10 hr. while working TABLE II. CUBIC YD. PER MAN PER 10 HR. AT STATED DEPTHS d d J d d CO 10 op o 13 2 2 3 3 + d ^- d d CO iO 00 8 gands 212 14.5 10.7 8.5 5.2 Gravel loose 15 4 11.8 9.2 7.7 4.9 Earth 12 8 10 5 9 75 49 Light clay ... 8.9 7.3 6.0 5.2 3.8 Dry clay 64 5.3 4.7 4.1 3.2 Wet clav 54 4.7 4.2 3.5 2.7 Hardpan 4 6 4.2 3.7 3.3 2.7 Average 10.7 8.3 6.9 5.7 3.9 at the depths stated. Table III shows the average number of cu. yd. per 10-hr, day that an average laborer should excavate work- ing from the surface to the depth stated. This figure for the same material is naturally somewhat greater than given in Table II. These figures may be increased by 30% for rapid workers and may be decreased 30% for inefficient workmen. The foregoing material may be now definitely classified as follows: Band. Weight, 3,000 Ib. per cu. yd. slightly damp. In natural bed. Not over 15% clay. Gravel. Weight, 3,000 Ib. per cu. yd. Loose, as excavated ma- terial. 112 HANDBOOK OF EARTH EXCAVATION LOOSENING AND SHOVELING EARTH 113 TABLE III. AVERAGE EXCAVATION IN CU. YD. PER 10 HR. FOR CUTS FROM SURFACE TO STATED DEPTHS ooooo Sand 21.2 18.1 15.1 13.6 10.7 Gravel, loose 15.4 13.7 ' 11.8 10.8 8.8 Earth 12.8 11.7 10.5 9.7 8.1 Light clay 89 8.1 7.3 6.7 5.8 Dry clay 6.4 5.9 5.4 5.1 4.5 Wet clay 5.4 5.1 4.7 4.4 3.8 Hardpan 4.6 4.4 4.2 3.9 3.5 Earth. Weight, 2,400 Ib. per cu. yd. Slightly damp, in natural bed, easily plowed, little or no pick work required. Would re- quire some sheeting in trenches over 6 ft. deep. Clay (light). Weight, 3,300 Ib. per cu. yd. Slightly damp, easily plowed. Not stiff or very cohesive, corresponds to yellow clay lying below the black soil and above the blue clay in vicinity of Chicago. Would require some sheeting in trenches over 6 ft. deep Little pick work required. Clay (dry, hard). Weight, 3,300 Ib. per cu. yd. Requires pick work equal to one-third time spent in shoveling and casting. No sheeting required at any depth. Corresponds to material on top of ravines along the lake shore in Lake County, 111. Hard plow- ing. Adobe in this class. Clay (wet). Weight, 3,900 Ib. per cu. yd. Tough and cohesive, has to be cut out in pieces. Slightly sticky, would require sub- stantial sheeting. Corresponds to the underlying " blue clay " of Chicago. Gumbo in this class. Hardpan. Weight, 3,360 Ib. per cu. yd. Requires picking equal to one-half the time spent in shoveling and casting. The use of the relative coefficient P is suggested as a simple and definite means of describing or designating any class of earth ex- cavation, t * f The jog in the curves (Fig. 13) at depth of 9 ft. represents an allowance of P = 1 on account of extra labor of shovel cutting done in recasting from a platform. As a matter of fact no re- casting may be done at the 9-f depth or even 1'4-ft. depth, but the output per man will not be increased over the quantity shown by the diagram. The recorded data platted on Fig. 13 are designated by a letter for the class of material. The number following the letter refers to the source from which the data were obtained, as follows : ( 1 ) "American Engineers' Pocket Book"; (2) "Handbook of Cost Data," Gillette; (3) " Earthwork," Gillette ; (4) L.K.Sherman; 114 HANDBOOK OF EARTH EXCAVATION (5) Windette, Journal West. tfoc. Engrs.; (6) "Concrete Costs,'* Taylor & Thompson; (7) Orrock; (H) Prelim; (9) Engineering and Contracting (December, 1008), "Atlantic, Iowa, Sewers," M. A. Hall; " Centerville, Ta., Sewers," M. A. Hall; (10) Engi- neering and Contracting; (11) Engineering and Contracting. From the output recorded by Mr. Sherman in the foregoing statement, we have deduced the outputs in average material at depths of from to 6 ft., 6 to 12 ft., 12 to 18 ft., and over 18 ft. These averages are presented in Table IV, together with averages of the outputs as given by Mr. Windette, given in the chapter on trenching and with those of the author, given in the same chap- ter. These average outputs, recorded by different engineers in widely separate parts of the country, compare very well. For a depth of from 12 to 18 ft. the average as noted by the author seems to be too high. This may be accounted for by the fact that this work was done under first class supervision and under other favoring conditions. TABLE IV, CU. YD. EXCAVATED PER MAN HR. WITH PICK AND SHOVEL IN AVERAGE MATERIAL Depth in ft. Authority 0-6 6-12 12-18 18 + 0.923 0.737 0.638 Author 1 050 0.720 0.370 0.260 Windett 0.950 0.630 0.390 Sherman In average materials the output per man-hour may be expected to be as follows: For depths of from to 6 ft., 1 cu. yd. For depths of from 6 to 12 ft., 0.7 cu. yd. For depths of from 12 to 18 ft., 0.4 cu. yd. For depths over 18 ft., 0.26 cu. yd. and less. Conclusions. From the foregoing data we may draw some prac- tical conclusions; for example: (1) Men should be close enough fo the wagon or other vehicle being loaded not to be required to take even a few steps before casting. (2) The farther away a man is from a wagon, the less number of shovelfuls he can cast in a given time. (3) As each shovelful is also smaller, a man 12 or 15 ft. away from a wagon will load about half as much as if he were only about 4 or 5 ft. from it. Therefore, in loading wagons, it does not pay to crowd men around it ; no more than six should be allowed. (4) Large shovels should be used. (5) Men should work to a face wherever possible. (6) A temporary floor should be laid down, so that the earth will fall on the floor, from which it can be more easily shoveled. (7) A high bank should be undermined with picks, and wedged off or blasted off LOOSENING AND SHOVELING EARTH 115 the top. (8) Picking should never be resorted to when plowing can be used. (9) When earth is loosened, by whatever means, it should be loosened thoroughly. Cost of Casting Clay for Filling in Behind Retaining Wall. (Engineering and Contracting, Jan. 22, 1908.) Some earth had to be cast behind a low retaining wall. The work was done by company forces, the foreman being paid $2.50 per day of 10 hr., and men $1.50. The material was a heavy black clay with a large amount of vegetable matter in it, and very wet. The men did not have to stand in the water, except in a few places, but their shovels were frequently submerged. The soil was exca- vated to a depth of from 12 to 18 in., and at high tide there was always water in the holes that were being dug. Most of the material was spaded, but where roots and similar material were encountered, mattocks were used to loosen it. The earth was cast from 5 to 10 ft., and the bank was made about 4 ft. high. The work was hard and difficult. The material stuck to the shovels, and the water disintegrated the clay, causing a man to make sev- eral attempts to get a fair shovelful when he was shoveling where there was water. ,; ^ ;' About 16 men worked under a foreman. The work was done in the early part of the winter. In all 522 cu. yd. of excavation, place measurement, was made. The cost per cu. yd. was: Foreman at 25 ct. per hr $0.043 Men at 15 ct. per hr 0.454 Total $0.497 This meant that one man loosened and shoveled in a day about 3i/ cu. yd., which is a small output. The Cost of Excavation for Pavement and 'Curb, New York. In an article in Engineering and Contracting, May 16, 1906, a writer gives the following cost for excavation for asphalt pave- ment and a concrete curb on Broadway, from 110th to 119th St., New York City, in November, 1904. Asphalt pavement excavation Per cu. yd. Foreman at $3.75 $0.026 Laborers at $1.50 201 Teams at $5.50 '., 0.088 Plowing at $4.00 018 Carts at $4.00 0.010 For 1,985 cu. yd., cost per cu. yd $0.443 Excavation for curbs Per lin. ft. Foreman at $3.75 $0.004 Laborers at $1.50 o!o20 For 2,253 lin. ft., per lin. ft $0.024 1 16 HANDBOOK OF EAETH EXCAVATION Teams with wagons cost $5.50, but as the contractor owned plows and carts, it was necessary to hire only teams and drivers, which reduced the daily rata per team to $4.00. Cost of Excavation and Backfill on a Bridge Abutment. Engi- neering and Contracting, May 30, 1906, contains the detailed cost of a masonry bridge abutment on the Detroit, Lansing & Northern R. R. The cost of excavation and backfill was as follows: Excavation Foreman, 8.9 days at $1.75 $15.58 Laborers, 64.8 days at $1.50 97.20 Engineman, 0.4 days at $1.75 0.70 Derrickman, 0.4 days at $1.50 0.60 Total, 772 cu. yd. at $0.15 $114.08 The removal of excavated matter was done almost entirely with wheelbarrows. The material was sand and was wasted. The overhaul was short, the lead being 75 ft. Backfill Foreman, 2.4 days at $3.00 $6.80 Foreman, 6.3 days at $1.75 11.03 Laborers, 37.8 days at $1.50 56.70 Engineman, 3.6 days at $1.75 .'." 6.30 Derrickman, 3.6 days at $1.50 5.40 Total, 380 cu. yd. at $0.23 $86.23 Excavation for Retaining Wall. The following from Engineer- ing and Contracting, May 30, 1916, relates to the construction of a retaining wall at the round house of the Detroit, Lansing and Northern R. R., at Grand Rapids, Mich. The contractor fur- nished the labor only. The excavation was nearly all stiff clay with stone and small boulders, making hard digging. Almost all of the excavated matter was handled twice, cast out on the ground and then loaded on flat cars. The time given for excavation in- cludes $6 or $8 worth of time spent in moving cars. In all of , the work the contractor was considered as a foreman and was allowed 40 ct. per hr. for the time he himself actually worked. In all of the cases the foremen hours are for the hours during which acti.al work was done by them; that is to say, the foreman not only acted as overseer, but also did actual work, excavating, laying stone, etc. The cost of the excavation work was as follows: Foreman, 33 hr., at 40 ct $13.20 Foreman, 104 hr., at 22% ct 23.40 Laborer, 285 hr., at 12% ct 35.63 Total .$72.23 LOOSENING AND SHOVELING EARTH 117 A total of 168 cu. yd. was excavated at a cost of $0.43 per yd. The contract price at which the work was let was $.0.25. In backfilling, the earth was wheeled from the flat cars and placed back of the wall. A small amount of earth was cast in directly from the bank. The cost of this work was as follows: Foreman. 4 hr. at 40 ct $1.60 Foreman, 11 hr. at 22% ct 2.48 Laborer, 52 hr. at 12% ct 6.50 Total $10.58 The back filling amounted to 63 cu. yd., and this was done at a cost of $0.17 per cu. yd. The contract price was $0.25 per cu. yd. Cost of Excavation for a Railway Culvert. This job, as de- scribed in Engineering and Contracting, Aug. 12, 1908, was done on some railroad construction in Tennessee. The culvert was a 4x4 box culvert of rubble masonry, 42 ft. long.' The excavation was 12 ft. wide and 2i ft. deep. The material excavated was a dry sandy clay that was easily worked, although it had to be picked before it could be shoveled. When material in culvert excavation can be spaded, thus saving the picking, the work can be done much cheaper. The excavated material in this case was shoveled on to the ground on each side of the culvert, the ends being left open. At each end of the culvert a ditch 4 ft. wide was c t to the culvert excavation, making 53 cu. yd. of excavation for the culvert and ditches. This earth piled up on the two sides of the pit would make about 65 cu. yd. loose measurement, making it necessary to handle some of the material a second time. This fact and likewise the width of the pit, 12 ft., necessitated casting the earth some distance, thus adding to the cost of the work. At least half the material was handled a second time, and about 10% wac handled three times. The cost of the work was as follows per cu. yd.: Foreman at 25 ct. per hr $0.14 Laborers at 12.5 ct. per hr 0.59 Water boy at 5 ct. per hr 0.03 Total .' $0.76 A man excavated, that is picked and shoveled, about 2 cu. yd. per day, of the original excavation, or about 3*4 c . yd. per day including the material that was handled more than once. This is a very high cost for this work. One reason for this high cost was a very inefficient foreman, lie was discharged. 118 HANDBOOK OF EARTH EXCAVATION Another reason was that the contractor did not furnish long han- dled shovels to the men. To cast the earth 10 ft. or more with short handled shovels was much more expensive than if long handled shovels had been used. In Engineering and Contracting, Aug. 5, 1908, the following cost of excavating for a culvert is given. This culvert was a 3x4 box masonry culvert, the excavation being 40 ft. long and 9 ft. wide, and averaged 1 ft. in depth. The material was sandy gravel and stiff clay. The stream was a small one and was easily diverted to one side, but, owing to the top soil being sandy gravel, the water percolated into the foundation as fast as it was dug. However, it was not necessary to pump it out, as a small trench ci.t at the lower end of the foundation pit carried off the water, care being taken in carrying on the excavation to do it so that the pit drained itself by means of this trench. However, this water made the clay wet and heavy and much more expensive to handle. The crew that clid the work consisted of a foreman and 4 men, who finished the job in one day. There were 13 cu. yd. of ma- terial excavated, at the following cost per cu. yd. : Foreman, at 25 ct. per hr $0.19 Laborers, at 15 ct. per hr 0.45 Total $0.64 This shows how large a proportion of the cost the foreman charge can be, where the gang is necessarily small. In this case supervision was nearly 33% of the total cost. Each workman in 10 hr. excavated 3% cu. yd. This meant that he loosened and shoveled it. With the material dry and in a bank it would have been possible for a man to have done at least 10 to 12 cu. yd. in a day, thus showing that prices paid for ordinary excavation would not cover the cost of this wet excavation. Labor Cost of Excavating in Stiff White Clay. Engineering and Contracting, May 15, 1918, gives the following: The following labor costs cover the excavation in stiff, white clay for a sewage disposal plant. The excavation was 19^ ft. long by 14 ft. wide, 7 ft. deep and contained 71 cu. yd. The work was done during good weather, but by a poor foreman and aver- age crew. Some water seeped in the bottom foot, delaying the work somewhat. The costs follow: Per cu. yd. Foreman, 40 hr. at 40 ct $0.225 Labor (excav.), 246 hr. at 35 ct 1.210 Labor (timbering), 16 hr. at 35 ct 079 Total (71 cu. yd.) $1.314 LOOSENING AND SHOVELING EARTH 119 The above costs cover excavation only. Hauling .away surplus earth is not included. The backfill (16 cu. yd.) cost 28-ct. per cu. yd. Handling Soft Material. On ditching work in light marshy soil where tough sod and numerous small roots are to be con- tended with, a hay knife will be found useful. This should be pushed as deep as possible along each side of the ditch, cutting the roots so that each spadeful has one side free. Other data on the subject of handling soft material will be found in the chapter on ditches. Excavating Swamps in Freezing Weather. In the Journal of New England Water Works Association, Vol. 15 (1900), Mr. John L. Howard gives a description of a method of excavating a swamp. A Hayward grapple excavator loaded the muck into the hopper from which it was distributed into cars holding about 1 cu. ydj each. These cars were hauled in trains of six by a hoisting engine to the top of the dump along which they were switched to the place of disposal. The muck was so com- pletely saturated with water that the dump became a quagmire. A platform was built under the track to keep it from sinking, but after every shower more planks and considerable labor were required to keep it in alignment, and even then the cars would not stay on. The difficulty was solved by waiting until cold weather set in. The surface of the ground became frozen and carts could be used without any difficulty. A pump sump was kept well down ahead of the excavator. Cost of Plowing. A plow or a pick is ordinarily used for loos- ening, the plow being the most economic under ordinary condi- tions. Whenever the word " team " is used I mean two horses and their driver; if I refer only to the horses, I shall say a horse or a pair of horses. A two-horse team with a driver and a man holding the plow will loosen 25 cu. yd. of fairly tough clay, or 35 cu. yd. of gravel and loam per hr. In the far West some contractors always use a four-horse plow even in light soils, but when very tough clay or hardpan is encountered a pick-pointed plow with four to six horses, and two extra men riding the plow beam will always be required, and will loosen 15 to 20 cu. yd. per hr. In such soil a steam roller or a tractor is very effective, and more economic than horses as a plow puller. One example to show the high cost of plowing the hard crust of an old road will suffice: An old village street, partially graveled, was plowed up 9 ft. wide X 1,400 ft. long X 14 in. deep 120 HANDBOOK OF EARTH EXCAVATION (= 55() cu. yd.) by one plow team with driver and a man holding plow, in 214 days, or 244 cu. yd. per day, at a cost of 2 ct. per cu. yd. Another similar but harder stretch was plowed with two teams on the plow and a man riding- the plow beam, at a cost of 6 ct. per cu. yd. While the average cost of plowing 5,500 cu. yd. of such compacted gravel and earth roadway was 4 ct. per cu. yd. for plowing alone, wages of men being 15 ct. an hour and team with driver 35 ct. an hour. Contractors having old streets or roads to loosen will do well to keep in mind these figures. Morris found that a team, a driver, and a plowman would loosen : 20 to 30 cu. yd. per hr. of " strong, heavy soil." 40 to 60 cu. yd. per hr. of " ordinary loam." Specht states that a six-horse plow with one driver and one plow holder would loosen 1,000 cu. yd. of sand, and 700 cu. yd. of sandy loam per day, ready for the buck scrapers to remove. Earthwork Plows are of rugged construction as their chief use is in very hard ground. A plow made by the Baker Mfg. Co. is shown in Fig. 14. It is made in the following weights and sizes : No. horses Beam Weight No. 2 6 ft. 180 ib. No. 1 2 to 4 6% ft. 200 Ib. No. 2 4 to 6 7% ft. 270 Ib. No. 3 6 to 8 8Ms ft. 350 Ib. All sizes cut a 12-in. furrow. Fig. 14. Railroad and Township Grading Plow. A plow weighing only 150 Ib., and said to be light enough for two horses and at the same time strong enough to resist the pull of ten horses is shown in Fig. 15. In tearing up hardpan, frozen ground, macadam, etc., a special type of plow called a rooter is used. It does not turn over the soil as does the ordinary plow but merely loosens it. A rooter plow which complete weighs 275 Ib. is shown in Fig. 16. It can be used with either horses or a traction engine. LOOSENING AND SHOVELING EARTH 121 Fig. 15. Light Grading Plow. Fig. 16. Steel Beam Rooter Plow. The following table gives the cost of plowing when wages of laborers are $1.80, and of teams (2 horses and driver) $5.40 per day of 9 hr. COST OF PLOWING Cu. yd. Soil Labor per hr. Loam 1 driver, 1 holder, 2 horses 50 Gravel and loam.l 1 2 " 35 Fairly tough clay.l " 1 " 2 " 25 Very hard soil...l " 1 " 4-6 " 2 men on plow beam of rooter plow 15-20 Ordinary soil 1 driver, 6 horses on gang 40 plow Per cu. yd. $0.014 0.023 0.032 0.035 Gang Rooter Plow. Fig. 17 shows the improved model of the Petrolithic gang road rooter plow (made by W. A. Gillette, South Pasadena, Calif.). It consists of a steel frame with two wheels in front and the same number in the rear. The wheels are con- trolled by levers so they can be raised or lowered from the ground. In this manner the exact depth to which the rooters or plows penetrate can be regulated. If it is desired to loosen a crust only 2 in. deep, it can be done; if it is desired to plow 122 HANDBOOK OF EARTH EXCAVATION to the depth of 12 in., this is also possible. The five rooters or plows are so fastened in the frame that any one or all can be removed if desired, and each rooter is provided with a removable point, which can be taken off and sharpened without removing the entire rooter from the frame. Only one man is required for operating a steam roller, which serves as a traction engine, and the gang rooter. At the end of a run, this engineman simply raises the rooters out of the ground by means of a lever, turns around, sets the levers again and goes back. Engineering and Contracting, Nov. 10, 1909, states that this gang rooter, and a road roller or traction engine, has actually broken more ground in one day than 12 horses hitched to an or- dinary rooter plow had previously broken in 6 days. Fig. 17. Petrolithic Gang Road Hooter Plow. Mr. W. A. Gillette, in Engineering and Contracting, June 28, 1911, gives the cost of plowing an old street with one of these Petrolithic gang rooters. The machine was drawn by a 12-ton gasoline road roller. One man operated the rooter, which was easily set so as to break ground at any depth from 6 to 15 in. in a strip 5 ft. wide. The gasoline roller developed sufficient power to pull the rooter in an old and very hard asphaltic oiled road. It lost very little time for stops and used a minimum of fuel, no stops were made during working hours to take on fuel. A usual day's work was nine hours. The operating cost of the roller was as follows: LOOSENING AND SHOVELING EARTH 123 Per day 35 to 40 gal, distillate @ 8 ct. per gal. $3.20 0.75 gal. lubricating oil @ 45 ct. per gal 0.34 J Engineman 4.00 Total $7.54 Dynamometer Tests on Plows. Engineering News, Aug. 17, 1911, published the results of some tests made by Wm. Clyde Willard In making the tests a " Pattern B " Schaeffer & Budenberg recording dynamometer registering to 4,000 Ib. was used. In this instrument the paper record slip was fastened on a drum 4 in. in diameter making one revolution per hr. The results in pounds were obtained by planimetric averaging from the record slips. The area enclosed by the dynamometer autograph, the zero line and the ordinate at beginning and end of run, was measured by a rolling planimeter. This area was divided by the length of the zero line to give average pull. Some difficulty was encountered owing to the fact that the clockwork which revolved the drum of the dynamometer ran so slowly that the lines made by the pencil overlapped each other to such an ex- tent that it was impossible to trace out each separate line. To overcome this the lines joining the points of maximum and mini- mum pull were traced by the planimeter and the mean of the two areas taken as the result. This probably gave as accurate a result as could have been obtained had it been possible to trace each pencil line throughout its entire length. In conjunction with the tests on wagons several tests were made to determine the tractive resistance of plows. The results should be of great interest to all users of plows or to those in- terested in farm mechanics. Two plows of different manufacture were used. Test group A (Table I) was made with a Parlin & Orendorf 14^-in. two-bottom gang plow; test group B (Table II) was made with an Oliver chilled 14l-in. two-bottom gang plow. Each plow was drawn by six horses. The results are tabulated below. TABLE I TRACTIVE RESISTANCE OF PLOW IN STUBBLE LAND Test Draft number Description in Ib. 1 7-in. cut, loose stubble land on about a 10% grade, man rode 900 2 Same as 1, except that man walked ,..,..............;... 883 8 All conditions the same as 1, except that the coulter was moved %-in. toward the land side of the furrow and sev- eral bolts about the plow were tightened 776 4 Same as 3, except man walked. (The increase in draft was caused by the plow not scouring for a part of the dis- tance. ) . . , 822 5 7%-in. cut, otherwise the same as 4 849 124 HANDBOOK OF EARTH EXCAVATION TABLE II. TRACTIVE RESISTANCE PLOW IN CLOVER SOD Test Draft number Description in Ib. 6 GV^-in. cut, heavy clover sod, almost level 949 7 6%-in. cut, thin clover sod, coulter ^-in. in furrow, furrow wheel ran free 850 8 Same cut and sod as 7, coulter ^4-in. outside of furrow, furrow wheel %-in. below land side 689 9 Same sod and cut as 7 and 8, coulter same as 8, furrow wheel %-in. below land side 697 In the tests reported in Table I, a change of ^ in. in the position of the coulter made a difference in draft of 124 Ib., or a difference of almost one horse. Tests 1, 6 and 7 show the differ- ence in resistance of the two sods and stubble. Tests 7, 8 and 9 show the change in draft made by a shift in the positions of the furrow wheel and coulter. Comparing 7 and 8 it is seen that shifting the position of the coulter %-in. and lowering the furrow wheel ^4'^ n - made a difference in draft of 161 Ib., or over one horse difference. Five horses could have pulled the plow easier after the shift than the six could before. The resistance is increased by having the furrow wheel too low, as shown in Test 9. Cost of Plowing with a Steam Traction Engine. Engineering and Contracting, June 16, 1909, gives the following: It is only within the last ten years or so that the feasibility of plowing with traction engines has become generally recog- nized. The results obtained have been very satisfactory, and when it is remembered that one man with a plowing outfit can do much more work than six or eight with horses, the advantages of this method on the large farms of the West are obvious. Some data on the cost of steam plowing taken from letters written to the manufacturers by users of the traction engine are given below. The first piece of work for which data are given was done in Missouri last year, a 20 hp. Rumley Standard traction engine and an 8-gang 14-in. Moline steam plow being used. An average of 18 acres per day was plowed, the cost of operating per day being as follows: Total Per acre Engineman $3.00 $0.166 Water and fuel, hauled with team 2.50 .139 Plowman 1.00 .055 Coal 3.00 .166 Plow sharpening, oil, etc 50 .027 Total $10.00 $0.553 The next piece of work was done in North Dakota, a 30 hp. Rumley engine and Emerson 16-in. plow being used. The cost was as follows: * ' LOOSENING AND SHOVELING EARTH 125 Per acre Coal, at $6 per ton, 90 Ib. per acre $0.27 Cylinder oil, at 40 ct. per gallon 01%, Machine oil, at 20 ct. per gallon 01 Fireman, $2.50 per day 06% Water, team and man for hauling, $4 per day 10 Sharpening lays 01 Gear grease, 4 ct. per Ib 00*4 Total $0.47 It will be noted that there is no allowance made for engine- man in the above, the owner of the outfit probably acting as such. Charging this item up at $4.00 per day would bring the cost per acre to 57 ct. The fireman also probably acted as plow- man. The outfit traveled 2^4 miles per hr., cutting 16^ ft., thus averaging four acres per hr., allowing for stops. The last piece of work was also done in North Dakota, a 30-hp. Rumley plowing engine being used. The ground was stony and hilly and a disc plow with 14 discs and cutting 11 ft. wide was used for breaking the ground. An average of 16 acres of ground was broken per 12-hr, day, the cost being as follows: Total Per acre Coal, 2,300 Ib., at $7.50 per ton $ 8.05 $ .50 Water, team and man for hauling 4.50 .28 Engineer 3.00 .11 Plowman (who also fired) 2.00 .12 Oil and incidentals 1.00 .06 Total $18.55 $1.07 Later on this ground was put in shape for the drill at a cost of about 50 to 60 ct. per acre. To do this the traction engine was used to three sections of 21 discs cutting 18 ft. wide with a large drag and float behind. Tractor Plowing. Mr. J. Gardner Bennett in Engineering News, Mar. 11, 1915, describes the use of a small gasoline tractor for breaking soft muck land on a Southern reclamation project. This machine was driven by a 20-hp. 4-cylinder motor, and was equipped with three small " caterpillar " wheels which gave a bearing surface of 2,800 sq. in. for a total weight of 4 tons. The price of the machine was $2,500. The cost of breaking soft muck land was about as follows : Operator's* wages for a 10-hr, day, $3; gasoline, $2; lubrication, $0.40. This gives a total op- erating cost of $5.40 for plowing five acres, or $1.08 per acre. Traction Plowing Outfits. Bulletin 170, U. S. Department of Agriculture, gives a large amount of data on plowing with trac- tion outfits, as well as on the cost of operating steam and gas- oline tractors under average farm conditions. Plowing costs are given as follows: 126 HANDBOOK OF EARTH EXCAVATION COST OF STEAM PLOWING (Including Harrowing) Cost per acre California |0.853 Southwest 1.14 Northwest , 1.73 Canada 1.898 The cost of plowing, including some harrowing, with gasoline engines is given as $1.409 per acre. The depth of plowing is not stated but it is safe to assume it as fully 6 in. An acre 6 in. deep contains approximately 800 cu. yd. Thus if farm condi- tions can be approximated on an excavation job, it will be pos- sible to loosen earth with traction-drawn plows at a cost of from 0.1 to 0.3 ct. per cu. yd. Loosening with Explosives. Some earthy materials are more ( economically loosened by explosives than by either picks or plows. Even where the material to be excavated is soft enough to plow, " the lay " of the land or the method of excavating may make plowing impossible. Explosives are the most economical means of loosening for drag line scraper and steam shovel work. In addition to loosening, explosives if used in sufficient quantities, will throw the earth considerable distances; as in making holes for tree planting or in digging ditches. In the " Engineer Field Manual, Professional Papers, No. 29, Corps of Engineers, U. S. Army," data are given as to the amount of explosive required to make military mines, from which the following brief tables are taken. The values given are to be regarded as approximations only. The maximum loosen- ing effect is obtained from the explosions of the powder when no earth is displaced on the surface. A sphere of earth is ruptured about the charge as a center. In military parlance this type of mine is called a " camouflet." Where the radius of rupture is to be equal to the depth at which the charge is placed, mul- tiply the cube of the depth in feet by the following factors to obtain the required number of Ib. of 50% dynamite. Light earth 0.005 Common earth 0.006 Hard sand 0.007 Hardpan 0.008 These factors apply to only one type of mine. According to them 1 Ib. of dynamite placed 6 ft. below the surface in light earth and properly tamped will rupture about 33 cu. yd. of earth. The amount of earth ruptured varies directly as the amount of powder used, but only if the conditions above set forth are fulfilled. Thus 2 Ib. of dynamite placed 6 ft. below the sur- LOOSENING AND SHOVELING EARTH 127 face will not rupture 66 cu. yd. because the surface will be broken and much of the force of the explosion lost. Placed 7.5 ft. below the surface the two pounds would rupture about 66 cu. yd. It is often desirable not to loosen the subgrade, in which case such blasting charges can only be placed at half the depth of excavation. Under these conditions it may be desirable to use larger quantities of explosives than above indicated, in spite of the fact that part of their force is expended in making a crater. In this case the relief of pressure in one side shortens all radii of rupture which have a component in that direction, and the volume of rupture is ellipsoidal. For a " Common Mine," dia- meter approximately equal to twice the depth of charge, having its greatest horizontal radius of rupture equal to 1.7 times depth of charge and vertical (downward) radius of rupture equal to 1.1 times the depth of charge, the following factors are given: Light earth 0.012 Common earth 0.015 Hard sand 0.042 Hardpan 0.050 9 Figuring from the above data a charge of approximately 2^ Ib. of 50% dynamite placed 6 ft. down in light earth will loosen about 48 cu. yd. of material. Here an increase of 250% in dyna- mite over the requirements of the " camouflet " produces less than a 50% increase in the amount of dirt loosened. While these figures are rough approximations they serve to show the folly of using excessive amounts of explosives in loosening earth. Consult Gillette's " Handbook of Rock Excavation," for further information on blasting. Cost of Blasting Hardpan. (From Engineering and Contract- ing, Aug. 19, 1908.) In all about 80 holes were drilled, each hole being put down to a depth of 6^ ft., making 520 ft. of drilling necessary. These holes were put down by two men with a 12-ft. churn drill, taking about 8 days to do the work. This meant 10 holes drilled per day, or about 65 ft., and, with wages at $1.25 for 10 hr., gave a cost for drilling of about 4 ct. per ft. It took about two days' time for these two men to dry the holes (water stood in the bottom of them) and do all the necessary blasting, thus costing about 6 ct. per hole for labor for blasting, making all the labor of drilling and blasting 4.4 ct. per ft. of hole. About 2 Ib. of 40% dynamite was used to the hole, 172 Ib. being actually used for all the holes. This meant an average of 0.28 Ib. of dynamite per cu. yd. of cemented gravel. The total cost of blasting was: 128 HANDBOOK OF EARTH EXCAVATION Laborers, 20 days, at $1.25 $25.00 172 Ib. dynamite, at 11% ct 19.48 80 electrical exploders, at 4 ct 3.20 Total $47.68 ,For the 600 cu. yd. of cemented gravel this is a cost of 8 ct. per cu. yd. for blasting, but if we distribute this cost for the 1,000 cu. yd. of excavation, the cost becomes 4% ct. per. cu. yd. This work was done in making a channel 20 ft. wide on top and 15 ft. wide on the bottom, 6 ft. deep and 250 ft. long. The top 2} ft. was sandy clay while the rest of the material was a hard cemented gravel. Breaking Up Hard Ground with Dynamite is described in En- gineering and Contracting, Nov. 13, 1912, as follows: Although road contractors have commonly used dynamite for blasting pocky cuts in road work, the use of high explosives for moving gravel, clay or old road beds is a recent innovation. At a demonstration given recently by the Du Pont Powder Co. to the Park Depart- ment of Los Angeles to show the value of dynamite blasting in hard ground, 30 holes were bored to a depth of 6 ft. (to grade), spaced 4 ft. apart and each loaded with two cartridges. As a re- sult of the blast the dirt was loosened to grade, making further plowing unnecessary. The ground was so hard that they had been using six mules to a plow and at each plowing were loosen- ing only about 8 in. of dirt. Low grade dynamites are best for this work, as they have the slow, heaving effect that is most advantageous in dirt work. Breaking High Banks. In excavating a high bank of hardpan, 12 to 15 ft. high, an economical method is to churn a hole some 8 to 10 ft. deep, and about 8 to 12 ft. back from the bank and to load this with a small charge of black powder. Sufficient powder is used to crack the bank, but not to throw very much of it down. Thus the earth is easily undermined or barred down, as the case may require, breaking into small pieces by reason of its fall. Excavating Holes with Explosives. The following is taken from Engineering and Contracting, Apr. 15, 1908. A hole was churned in the ground where the tree was to be planted, with a churn drill, at an angle with the surface of 35 to 40. The hole was made about 2 ft. deep, and loaded with a half stick of 40% dynamite (14 Ib.) and shot. This blew out of the ground a hole about 3 ft. in diameter and about 2 ft. deep, making a hole the shape of a cone. The soil left in the bottom of the hole was well pulverized, admitting of the tree being planted without further preparation. One man accustomed to handling explosives, with a helper, blew out on an average 250 holes per day, working 10 hr. The LOOSENING AND SHOVELING EARTH 129 dynamiter prepared the charges and loaded the holes, tamping them but little, while the helper churned the holes and assisted in other work. The cost of blowing 250 holes was: 1 man $3.50 1 man 1.50 500 ft. fuse at 45 ct. per 100 ft 2.25 250 caps at 75 ct. per 100 1.87 63 Ib. of dynamite at 15 ct 9.45 Total $18.57 This gives a cost of 7.4 ct. per hole. From each hole about 4.7 cu. ft. of earth was excavated, being equal to .17 cu. yd. At the above cost this makes 43 ct. per cu. yd. In such a hole trees as large as 4 in. can usually be planted. With a deeper hole and a larger charge of explosive larger holes could no doubt be blown out. It would also be possible to use either black powder or Judson instead of dynamite, and the work might be cheapened by the use of either of them. See Gillette's " Handbook of Cost Data " for further informa- tion on hole digging and tree planting. Blasting a Pit for a Dredge. In order to float a dipper dredge for the purpose of digging a ditch at Madrid Co., Mo., according to Engineering News, June 24, 1915, it was necessary to exca- vate a pit 136x50x6 ft. in size. Eleven rows of holes, 3 ft. apart, were driven. The holes in the center row were loaded with 2.5 Ib. of dynamite each, those in the next two rows on each side 2 Ib. each, in the next rows with 1.5 Ib. each, in the next with 1 Ib. each and in the outside rows with 0.5 Ib. each. The holes in the outside rows were 18 in. apart, in the next rows, 2 ft. apart, in the next 2.5 ft. apart, and in the rows alongside the middle row, 15 in. apart. A total of 950 Ib. of dynamite was used. The blast resulted in a hole 136x43 ft. in area, 7 ft. deep at the center, and an average of 3.5 ft. deep. In all, 747 cu. yd. were removed at an expenditure of about 1.3 Ib. per cu. yd. Eliminating a Mosquito Breeding Pool by Blasting. The fol- lowing item was extracted from the Year Book for 1916 of the Commissioners of the Borough of Haddonfield, N. J. (Engineer- ing and Contracting, Aug. 9, 1916.) " The residents of West Haddonfield were for years pestered and tormented by mosquitoes which it was learned, upon in- vestigation, were propagated in stagnant pools between the rail- road and Haddon Ave. It was found practically impossible to drain these to the street gutters, hence another method had to be employed and it was decided to sink the water into the ground. Under the supervision of L. Z. Lawrence a heavy charge of dy- 130 HANDBOOK OF EARTH EXCAVATION namite was sunk and discharged about 20 ft. under the surface. This caused the pools to disappear in short order and no water has accumulated at this point up to the end of the year." Dynamiting a Dredge way. Paul R. Higgings, in Engineering and Contracting, Aug. 16, 1916, is author of the following: A small creek ran under a concrete bridge 22 ft. in width. It was desired to run dredges under the bridge, but the creek was not deep enough, nor wide enough. I was given the contract at a price of 80 ct. per cu. yd. to deepen and widen the creek for 60 ft. on either side of the bridge. I began operations directly under the bridge. It was imprac- ticable to load heavy charges at that point, so I put down a row of bore holes 2 ft. back from the bank of the stream, spacing them 2 ft. apart and making them 2 ft. deep. Each hole was loaded with a half stick of 60% dynamite. I worked in this way from both ends toward the middle. It was necessary for me to make use of these little shots at the 2-ft. distances all the way down these lines in order to get the required excavation. This method of blasting resulted in "throwing most of the dirt into the creek bed, which was at that time dry. Two hours' work with team and scraper at a cost of 50 ct. per hr. were re- quired to remove the dirt. After finishing under the bridge, the work was much easier, as I could load more heavily. Parallel rows of holes were put down on each side of the creek 2 ft. back from the banks, 6 ft. deep and 4 ft. apart, each hole loaded with from seven to nine 5'to6' 7'[/-~^\ 7' B Creek thru. Center ESC Fig. 18. Method of Enlarging a Creek Bed by Dynamite. LOOSENING AND SHOVELING EARTH 131 sticks of the 60% dynamite. An electric cap was used in each charge and the charges were fired electrically. Fig. 18, Al, will illustrate this operation. These side blasts threw most of the dirt over into the dry creek bottom, leaving the work in the con- dition indicated by diagram B, Fig. 18. I then put down a single row of holes directly down the center of the hump, also two more parallel rows of holes on either side of the center line. These side lines were each about 3 ft. from the center line. The center line of holes was about 6 ft. deep; the side lines from 3 to 4 ft. My center line of holes (all the holes were from 2 to 3 ft. apart) was loaded with about 4^ cartridges each of the straight dynamite, and the side line of holes with about three cartridges each. This final shot resulted in throwing the dirt out on the banks, leaving a nice clear ditch nearly 20 ft. wide at the top and about 12 ft. wide at the bottom. Diagram C, Fig. 18 will illustrate the loading for this last shot and the approximate shape of the ditch after the blast. Digging Ditches with Dynamite. Arthur E. Morgan in En- gineering and Contracting, Feb. 1, 1911, is author of the fol- lowing : In the lowlands of southeast Missouri, a considerable amount of excavation for drainage ditches is now being made with dyna- mite, a method of construction discovered by accident in 1909. In blowing large stumps preparatory to digging drainage ditches, it was noticed that where several stumps close together in a line were blown out, a depression remained which had approximately the dimensions of the required ditch. Acting on the suggestion thus offered, efforts were made to blow out a channel by placing a single charge at a time, with results which were not satis- factory. Next charges were placed in the ground 2 ft. apart for a distance of 100 or 200 ft., and an effort was made to dis- charge them at about the same time by means of fuses. As the explosion of all charges was practically instantaneous, it was apparent that all but the first had been discharged by concussion. The experimenters continued setting charges 2 or 3 ft. apart for distances up to a quarter of a mile, and found in all cases that it was necessary to set a fuse to only one of the charges, in order for the whole to be exploded. Up to the present this method is in use only for the construction of small ditches 3 or 4 ft. deep and 6 to 12 ft. wide. The dirt removed by the dynamite is thrown onto both sides for 100 ft. or more, and does not lie more than 6 in. or 1 ft. deep along the margins of the ditch. The charges are set by making a hole of the necessary depth with a bar, and then push- 132 HANDBOOK OF EARTH EXCAVATION ing the dynamite into the hole with a wooden stick, tamping dirt on top. In order to secure a uniform cross section it is found necessary to place the charges at equal distances apart, and at such a depth that they will be on the proposed bottom line of the ditch, and that the charges should be approximately equal in size. The best of the channels constructed in this manner are as nearly uniform in cross section as they could be made by using teams and scrapers. One of the ditches examined, which had been constructed about a year, was 6 ft. wide on the bottom, 12 ft. wide on top, 3^ ft. deep, and in good order. In digging it two ^-lb. sticks of 50% dynamite were placed 3 ft. apart in the ground and between 3 and 4 ft. deep. Two men will construct a quarter of a mile of ditch in a day. At a cost of 15 ct. per Ib. for dynamite, and $20 per mile for placing the charges, the ditch in the condition in which it was examined, after a year of depreciation, had cost about 5 ct. per cu. yd. The ditch had been constructed through the woods without cutting down any of the trees, and in some instances the fallen trunks were lying across the channel. This method of construction is coming into general use in ex- cavating lateral ditches in the wet muck soils of southeast Mis- souri. Its advantages lie in its usefulness for digging ditches too small for a dredge, and through ground too wet for economical work by hand or with teams and scrapers. Whether larger chan- nels can be constructed by using larger charges of dynamite, placed at greater depths, remains to be seen. Sandy soils are not handled as readily as clay or muck, and where ditches have been blown out in sand, the cost per yd. has been several times as great. Neither does the method work well in dry soil. The use of 60% dynamite has in some cases given better results than 50%. If the success achieved by this method of excavation is repeated in other parts of the country, it will appear that we have added to our construction methods another means of earth excavation, applicable to wet muck and clay soils, under conditions where none of our former methods of excava- tion were economical for the construction of small channels. Ditching and Digging Pole Holes win Dynamite. From an article by Thomas M. Knight in Engineering and Contracting, July 19, 1916. There are hundreds of thousands of miles of ditches needed in this country. Excess water must be carried away, and in the arid regions water must be brought to the land. Ditches both small and large, deep and shallow, to fill the particular LOOSENING AND SHOVELING EARTH 133 needs are required. How to dig these ditches at the least cost in the quickest time possible is a question of vital interest to the engineer. In times past, pick and shovel, mechanical diggers, heavy ditching machinery and floating dredges all played their part in the excavation of ditches. In recent years dynamite has been added to this list. All of these methods have their place; yet for a great many classes of ditches the use of dynamite is cheapest and most satisfactory. However, in cases of ditches of from one to several miles in length and 6 ft. deep or over other means than by the use of dynamite will probably be found more economical, but for ditches from 3 ft. wide to 2 ft. deep up to 16 ft. wide and 6 ft. deep the use of dynamite will be found to be a very economical way of digging. Ditches may be dug with dynamite in the softest swamp lands or through the hardest rock. In fact, dynamite will do the work in any soil, with the exception of loose, dry sand. In ditching with dynamite no expensive machinery is required, and the cost and labor of transporting this machinery is elim- inated. The equipment required is generally a sledge and punch bar or soil auger, and very often two men can carry all the sup- plies that are needed for a few hundred feet of ditch. Dynamite works exceptionally well in rough and swampy lands, and will dig a clean-cut channel through places so wild that teams or machinery could not be brought to work in them. A little shoveling is sometimes required, and, as the blast scatters the soil over an area approximately 150 ft. on each side of the ditch, there are no spoil banks with which to contend in after- times. It is as easy to dig a curved ditch as a straight one, as the center of the ditch is where the dynamite cartridges are placed. In wet weather it is often imperative that a ditch be dug very quickly to avert the flooding of certain sections, and the use of dynamite in cases like this is the means of saving an untold number of dollars. There are two methods of blasting ditches, propagated and electric. The propagated method can be carried on only in wet soils, while the electric one may be practiced in both wet and dry soils. The grades of explosives used, blasting supplies needed, and methods of loading vary with the two methods. In wet or swampy soils the ditching can best be done by . the propagated method. In firing a propagated blast the car- tridges are placed from 18 to 24 in. apart and at the proper de- termined depth. A blasting cap with fuse is inserted in the center cartridge and fired. The force of the explosion of this 134 HANDBOOK: OF EARTH EXCAVATION cartridge fires or. detonates the balance of the cartridges so placed. If the ditch is to be a wide one, then a parallel row of cartridges, and sometimes a third row, is required. In such a case there should be an extra cartridge or two put down to con- nect the parallel rows to make sure of the simultaneous detona- tion of all the charges. It is also good practice to charge the two cartridges on each side of the primer with a blasting cap, to further insure perfect detonation. In a propagated blast a straight nitroglycerine dynamite must be used, as other grades are too insensitive to be fired in this manner. This method of blasting should be carried on only in a fairly warm soil. It should not be attempted in icy water or in cold weather. If stumps, boulders, or other obstructions are directly in the line of the ditch it is best to prime a cartridge on each side of the obstruction and fire these with an electric blasting ma- chine. The explosive wave might carry through or around these, but it does not pay to take the risk. When such obstructions are to be removed from the ditch, extra charges should be placed under them. The electric method of blasting ditches may be carried on re- gardless of soil conditions and temperature. It has the advan- tage over the propagated method in that the low freezing and less sensitive grades of dynamite may be used and larger charges may be employed in the hole, and these placed correspondingly farther apart, thus reducing the cost. The method of procedure is exactly the same as with the propagated blast, except every charge must be primed with an electric blasting cap, and the wires connected up. To fire this an electric blasting machine is used. Where more than one cartridge is used in a hole, the one containing the primer should be placed on top and the cap pointed downward. Blasting machines have limited capacities; so don't overload them. If one is rated at fifty, it is far better to fire forty-five charges than to try to fire fifty-five. Be on the safe side. Where the water does not rise 2 ft. in the hole, it should be filled with suitable tamping material and packed tightly. If one set of holes is to be fired they can best be connected as shown in Fig. 19. Fig. 20 also shows a method of connecting one line of holes. For two sets of holes the connections are made as in Fig. 21. If a ditch is of a sufficient width to de- mand three lines of holes, the method of connecting the wires is shown in Fig. 22. Fig. 23 gives a view of the longitudinal section of the placing of charges and wiring for an electric ditch blast. The amount of dynamite needed, the space between the charges, LOOSENING AND SHOVELING EARTH 135 Fig 19. Plan of Wire Connections for Blasting a Narrow Ditch Through Dry Ground. Fig. 20. A Second Method of Wiring One Line of Holes. Fig. 21. Plan Showing Method of Connecting Wires for Blasting a Large Ditch Through Dry Ground. Fig. 22. Method of Connecting Wires for a Ditch Blast Where Three Lines of Holes are Used. CONNECTING Wine TO L CAD/KG Wl* IT ii w- &o~or/ar* Fig. 23. Longitudinal Section Showing Method of Loading With Electric Blasting Caps for Blasting a Ditch. 136 HANDBOOK OF EARTH EXCAVATION and the depth to which they are placed to dig a ditch of the required size vary greatly. No set rule can be laid down. Roughly speaking, in average soils a pound of 50% straight nitroglycerine dynamite should dig a running yard of ditch 6 ft. wide and from 2y 2 to 3 ft. deep. That would mean the placing of a cartridge of dynamite every 18 in. at a depth of about 30 in. The only sure way to proceed either in a propagated or electric blast is first to fire trial or test shots. For ditches from 3 to 3% ft. deep the depth of the bore or loading holes should be from 2 to 2} ft. and the spacings from 20 to 24 in. apart. It is well to load about ten holes as a trial and note the results. If a clean ditch has been blown to the required width and depth, the work may proceed, but if too deep or too shallow, vary the spac- ing, depth, and charges accordingly. Two or three test shots in most cases will determine the correct loading. In some cases where a shallow ditch is required and the soil is soft and wet, half a cartridge will be sufficient to do the work. When the dyna- mite moves too much ground in propagated blabts and the spacing Fig. 24. Dynamite Charges Tied to a Stick and Ready to Load for a Post Hole Blast. between the charges is 24 in., cut down the size of the charge rather than increase the spacings, as 24 in. is usually the limit of successful propagated blasts. The holes can be put down in swampy and wet land with a wooden stick or bar with little trouble, while in harder soils a hole may be put down with a bar and sledge or crowbar. Soil conditions vary in every location; so it is impossible to arrive at any cost prices until test shots have been made. Table I gives the approximate amount of 50% straight nitroglycerine dynamite required to dig ditches of various width. Table II shows the amount of dynamite required for a given length of ditch. Dynamite is also employed to good advantage in digging post and pole holes. In digging pole holes with dynamite the dirt is packed solidly around the sides of the hole, which is greatly to be desired. The tendency in hand digging in hard soils or shale is to make the holes shallow. This danger is wholly eliminated where explosives are employed. In preparing to blast out a hole with dynamite, a hole is first LOOSENING AND SHOVELING EARTH 137 dug with a spade about 6 or 8 in. deep to the full diameter of the hole required. This is to relieve the pressure on the blasted hole and to prevent excessive shattering. . A bore hole is then put down in the center of the shallow hole to within about 6 in. of the depth required. A soil auger or churn drill will probably work the best in putting down this hole. The dynamite used in blowing out the hole must be divided into several charges and spaced so that when placed in the hole the top charge will be about 20 in. below the surface. The charges, consisting of a cartridge or fraction of one, may be tied to a lath or any other light stick (see Fig. 24) at distances from 6 to 24 in. apart. The spacings and charges are determined by the character of the soil and depth and diameter of the hole required. Fere, again, test shots must be made to determine the most satisfactory and economical method of procedure. TABLE I. APPROXIMATE TABLE OF CHARGES OF STRAIGHT 50% DYNAMITE FOR BLASTING DITCH WITHOUT A BLASTING MACHINE Top width of ditch 6 8 10 12 14 16 18 Approximate number of cartridges per hole required for ditches of various depths 2V 2 to 3 ft. 1 1 1 1 1 1 1 4ft. 5ft. TABLE II 6ft. 5 5 5 5 5 Number of parallel rows required 1 lor 2 2 2 2 3 3 Distance between rows in inches SO 36 42 48 36 42 between holes in. , 10 rods , Dynamite required using co charges 2 per hole of I o of holes "j 14 mile \ Dynamite required using charges per hole of fi *, i 1 % mile ^ Dynamite reqxiired using charges per hole of t* L 1 fe o> . |S I.S S - 01 'II Q II II | II If 18 110 28 55 880 220 440 1,760 410 880 20 99 25 49 792 198 396 1,584 396 792 . 24 83 11 41 664 166 332 1,328 332 664 26 76 19 38 608 152 304 1,216 304 608 28 71 18 36 566 142 284 1,132 283 566 9JlJ J, 1 rod 16% ft. tad* 10 rods 165 ft. or 55 yd. mile 1.320 ft, or 440 yd. or 80 rods, mile 2,640 ft. or 880 yd. or 160 rods. 138 HANDBOOK OF EARTH EXCAVATION The top cartridge or piece of cartridge is primed with a fuse and blasting cap or an electric blasting cap. (Nothing smaller than ft No. 6 should be used, so as to insure perfect detonation.) The lath with the primer on top and charges attached is then placed in the hole ( see Fig. 25 ). If water is in the hole of suffi- Fig. 25. Method of Loading for Pole Hole Blasting. cient depth to cover the charges, including the primer, no tamping is necessary. If, on the other hand, the hole is dry, better re- sults may be secured if the hole is tamped at the top about the charge. In tamping the hole care should be taken to see that no dirt or pieces of sod get between the primer and charges LOOSENING AND SHOVELING EARTH 139 below. In firing, the force of the explosion of the primer explodes the other charges, but if dirt or sod intervenes the charges below will fail to explode. Water transmits the detonation, but dry dirt retards or cuts it off entirely. In a test shot following the described method in a tight clay soil, an excellent, clean-cut, open hole was blown out 4.5 ft. deep. One-third of a cartridge of straight 60% dynamite was placed in the bottom of the hole; one-third of a cartridge of the same strength eight inches from the bottom, and one-half cartridge of 40% low freezing extra dynamite was placed 20 in. below the top. There was no tamping in this case. Very little hand work was required to clean the hole out. Another test shot was recently made in a wet blue clay soil. A bore hole was put down 6 ft. deep. Seven charges, each con- taining one-third of a cartridge of 50% straight nitroglycerine dynamite, were placed 6 in. apart, beginning at the bottom. This blew out a uniform, clean-cut hole, 78 in. deep, which required less than three minutes of hand work to clean out. The walls were compact and hard. The shot was satisfactory in every way. In pole hole blasting the straight dynamites give good results in warm weather, while the extras and low freezing grades give satisfactory results both in warm and cold weather. The straight dynamites are more sensitive and quicker in their action than the others. Undercutting Frozen Ground. One of the simplest methods of excavating frozen ground where the depth of freezing is not too great, is to undercut it and to break the unsupported crust with heavy sledges. Methods of Digging Pole Holes in Frozen Ground. The fol- lowing is from Engineering and Contracting, Dec. 3, 1913. In northern Minnesota, where the earth freezes to a depth of from 4 ft. to 5 ft. in winter and where consequently the cost of digging holes is high, the following expedient is used to keep down costs. When the top of the hole has been picked out to a depth of 6 in. or more, a tin cup full of gasoline or coal oil is poured into the hole and lighted. The digging is then con- tinued, the burning oil thawing the earth, and from time to time more oil is added. It is said that with the help of about a gallon of oil per hole, the cost of digging can be reduced approx- imately 15%. Steam jets have been successfully used. For example, in En- gineering 'News for April 13, 1899, a description was given of a method used for thawing frozen ground in order to dig holes for electric light poles, from which the following information is ab- stracted. 140 HANDBOOK OF EARTH EXCAVATION A vertical jet pipe was connected by a tee to a horizontal pipe 24 in. long, capped at one end and connected at the other by nipples and four elbows with a pipe leading to the boiler of a traction engine. The nipples and elbows were provided to allow the necessary play for handling the appliance. To protect the workmen from the steam and to enable them to manipulate the jet pipe, two wooden handles 2x4 in. in section and 10 ft. long were connected by stirrups to the two ends of the short horizontal pipe. This jet pipe was forced down by two men pressing on the handles; as the earth thawed out, the steam carried the particles out alongside the pipe; and as the depth increased more steam would be condensed in the borehole until finally no steam escaped and the outflow was liquid mud. This outfit, which was invented by Mr. James W. Pearl, of Decatur, Mich., would thaw out about 30 holes for electric light poles in a day of ten hours. Thawing Ground with Steam Pipes. An article by Mr. A. Len- derink, in Engineering News, Feb. 18, 1915, gives the following: An interesting method of thawing ground for trenching was employed during the winter of 1914 and 1915 at Kalamazoo, Michigan. The ground in the streets was frozen 18 to 24 in. deep and this was thawed by the following method: A 10-hp. upright boiler and engine (mounted on a truck so that it could be easily moved about) furnished steam to a 1-in. steam line, laid along one of the outer edges of the proposed trench for a distance of 100 to 150 ft. from the boiler and returned along the other edge. This part of the trench, including the pipe, was then covered with some wooden sewer forms that the city had used for large concrete sewer construction, and the forms were covered with 6 to 8 in. of sand. The pipes were kept off the ground by laying them on a few bricks. It was found that by keeping steam on the pipe for 24 hr. the frost in the part under cover was entirely removed. The mois- ture in the thawed ground allowed the men to shovel the top dirt out of the trench without using a pick to loosen it. The pipes and forms were moved ahead each morning and the thawing started for the next day's work. The cost of thawing, for a trench 3 ft. wide, was 8 to 10 ct. per lin. ft., exclusive of interest and depreciation on the boiler. A Device for Thawing Holes, made by Hauck of Brooklyn, consists of an oil burning blow pipe which is used inside of an 18-in. length of stove pipe. The ground is warmed ancl dug out with bar and scoop to the full depth but to a diameter of from 8 in. to 12 in. only. The hole is then filled with the warmed earth, covered and allowed to stand over night. The warmed LOOSENING AND SHOVELING EARTH 141 earth thaws the adjacent frozen earth so that the hole may be excavated to the full diameter. Lime for Thawing Frozen Ground. The following is from Engineering Record, March 22, 1913. In connection with the sewer construction at West Liberty, Iowa, described in the En- gineering Record of Mar. 15, 1913, a novel method of fighting frozen ground was used with considerable success. During the winter of 1911 and 1912 the ground was frozen to a depth of about 4 ft., and in this state resisted all efforts of the trenching machine to break it. Finally lime was placed, covering the width of trench to be opened, and was broken up into small pieces and covered with straw, hay or manure. Water was poured upon it so as to slake the lime thoroughly. The covering retained the heat, which with the hot water penetrated the frozen ground sufficiently to enable the trenching machine to make headway. On another job a covering of old boards with a steam jet was found to hurry matters up. This method of thawing ground is now being used successfully by Thos. Carey & Son in Clinton, Iowa, where they have been vigorously prosecuting sewer work all winter. Thawing Frozen Gravel. In " Methods and Costs of Gravel and Placer Mining in Alaska," by C. W. Purington (U. S. Geol. Sur- vey Bui. No. 263, 1905), various methods of thawing gravel for mining purposes were described substantially as follows: According to experience in one district the efficiency of a good fire in creek ground was as follows : A fire taking three-fifths of a cord of wood (at $12 a cord) is built against the face of the bank. The pile of wood is 18 in. wide, 2 ft. high and 25 ft. long. Stones are laid up over the pile and a space is left to light the fire. The fire is lighted at 5 p. m. and left to burn until 8 a. m. the next day. The stones, which quickly get hot, are regarded as most efficient in thawing. On a 4-ft. thickness of pay gravel this amount of fire will thaw in the time specified from 5 to 6 cu. yd. This is at the rate of 9.2 cu. yd. thawed per cord of wood, which is considerably less efficient than the method of thawing with steam. Time, delays and awkwardness of the method, moreover, make wood fire thawing the most expensive that can be adopted. The figures per ft. for shaft sinking range from $3.16 to $7.50 in taking gravel from prospect shafts. The direct application of jets of dry steam to the gravel bank through the agency of driven pipes has been found to be the most efficient method in general practice for thawing frozen gravel. The amount of moisture contained in steam can be judged by the color of a jet of steam issuing from a small brass petcock. If it is transparent or whitish near the orifice it con- 142 HANDBOOK OF EARTH EXCAVATION tains less than 2% of moisture. If pure white the moisture is above 2%. A %-in. steam hose is run from the boiler to the bank, where it ends in a manifold to which several %-in. hose lines can be coupled. Each of these small lines ends in a hollow bar about 5 ft. long with a tool steel point which is driven into the gravel and enables the jet of steam to penetrate far into the interior of the frozen mass. In creek claims exceeding 15 ft. in depth, where solidly frozen ground occurs, the method of drifting with the use of the steam point is as follows. A 20-hp. boiler, capable of running 10 steam points, is put on the ground, and frequently one or two extra long points are pro- vided for sinking holes. These long points, from 10 to 12 ft. in length, are not so strongly made as the 5-ft. points used in the drifting operations. In some cases pieces of %-in. hydraulic pipe are used. The point is set up on the ground and steam or hot water is turned on. The time for sinking a hole by this method to bedrock is from 24 to 48 hr. If large flat stones are en- countered in the gravel it is sometimes advisable to use strong, specially made points to prevent breaking. The average radius of a vertical shaft thus thawed by a single point is 2 ft. and the hole when cleaned out has a cylindrical or tube shape. On some of the work the 5-ft. points are used in batteries of four points each. A mallet is used to drive the points into the bank, where they are left from 10 to 14 hr. Each point thaws a block of gravel averaging 6 ft. into the bank, 18 in. on each side of the bank and 4 ft. high. The use of hot water turned into the hose for starting the points is considered good practice. The points must be driven carefully and slowly, and for ten points distributed along a face the average time needed is from one to three hours. The amount of steam required for each point has been found to vary in amount from 1 to 2 boiler lip. The amount of gravel which a point will thaw appears to vary with the length of the point, and this is regulated somewhat by the character of the gravel. The 5-ft. point has been found to be the most economical. A typical case illustrating the efficiency of the points is the following: Points of Dawson manufacture, 5 ft. long, costing $15 laid down, were used in manifolds of four. They were put in at distances of from 2 ft. 6 in. to 3 ft. apart, and were started with hot water. It took three hours to drive them in. A 12-hp. boiler supplied the steam for ten points, three-fourths of a cord of wood being burned while the thawing was done. In twelve hours the ten points thawed a block of gravel 30 ft. in length by 5 ft. high, 6 ft. into the bank or a total of 33.3 cu. yds. This ia LOOSENING AND SHOVELING EARTH 143 at the rate of 3.3 cu. yds. per point and 44.4 cu. yds. per cord of wood. Steam Jets Thawing Ahead of Steam Shovel. (H. P. J. Earn- sliaw, in Engineering Xews-Kecord, Sept. 13, 15)17.) Thirty-four inches of froxen clay, so hard that stones embedded in it could be cut off without loosening them at all, which was encountered on a recent excavating contract, was readily thawed by the fol- lowing method. It was impossible to lift or break this frozen crust, and ordi- nary means of thawing, such as steam pipes under canvas cover, and live steam under canvas cover, proved such a failure that only 4 or 5 in. were thawed out in 36 hours. The plan used was to jet holes with an open-end %-in. pipe connected to the boiler by a %-in. hose, the steam pressure quickly melting a hole in the frozen clay and forcing pebbles and small stones out of the way. As fast as these holes were made a ^-in. capped pipe with four ^-in. holes bored in it was put in each and left running to thaw out the ground. These pipes were connected in series by short lengths of hose to steam lines run from the boiler. Twelve of these were put in at a time, connected to one line. These were moved back as the shovel worked toward them, requiring only 15 minutes to thaw out a section of the bank so thoroughly that the revolving shovel could dig it as well as if it had never been frozen. Thawing by Direct Application of Hot Water is described in Engineering and Contracting, Aug. 14, 1907, as follows: At a claim on Gold Run, in the Klondike, where it was desired to ex- tract a 3-ft. pay streak of gravel capped by 27 ft. of barren gravel at a depth of 50 ft. below the surface, a small force pump of the ram pattern, with out-side packed valves, was placed in the main runway near the shaft. It drew water from a 6-ft. sump near at hand, to which the workings drained. The pump had 4-in. intake, 3-in. discharge choked to 2% in., and the water was pumped to the face by means of cotton hose and discharged through a 1-in. brass nozzle at 40-lb. pressure. Six thousand gallons of water were used over and over, and by discharging the exhaust from the pump into the suction the water was kept at a temperature of 150 F. In a shift of ten hours the pump, using 30 hp., thawed and broke down ready for the shovelers 175 cu. yd. of gravel. Hot Water Thawing. It is stated by Mr. Henry Mace Payne in a paper read before the Canadian Mining Institute, and ab- stracted in Engineering and Contracting, April 17, 1918, that ex- perience in the Yukon District shows that with hot water four times the amount of gravel can be thawed in two-thirds the time 144 HANDBOOK OF EARTH EXCAVATION with less than half the fuel necessary when steam is the medium used. An average of 40% of the frozen material in place is ice. When this is melted, the boulders are loosened, so that a thawing process started at bed-rock creates a subterranean cavern, which, as the thawing continues, causes a gradual caving to the surface and a shrinkage in volume of the entire mass. To drive the thawing points to bedrock a hollow-steel rock- drill cross-type bit was welded to the end of a %-'m. steam point and a %2-in hole was drilled at the top of each of the four flutes to the bit. Thus, instead of one %e- in - nole at the end > as in tne old point, there are five holes, four in the sides and one in the end, and as a result it is possible to drive the point directly through a boulder. A frozen boulder when partly drilled through expands from contact with the hot water and splits, allowing the point to drop 5 u y < Fig. 26. Anvil Attachment for Thawing Points. below to the next boulder. Meanwhile the hot water has a sluicing effect from the four side holes, not obtainable with the one orifice only, and thawing proceeds with consequent greater rapidity. A further advantage of hot-water thawing is the elimination of the possibility of back pressure or suction through the thaw- ing point, with consequent choking by mud, etc,, due to steam con- densation in the lines, or pressure drop in the boiler. To facilitate driving of the thawing points and to eliminate the use of ladders and chances for breaking points, anvils weighing about 100 Ib. may be forged from old dredge-bucket pins, slotted so as to pass over the thawing point, and held in place by a key. (See Fig. 2C.) Handles may be inserted on each side of the anvil and the helper can turn the point as in regular rock drill- LOOSENING AND SHOVELING EARTH 145 ing, while the operator standing on the ground alongside strikes with a sledge hammer, driving the point until the anvil reaches the ground. The key can then be knocked out, the anvil raised to a convenient height, and the driving operation resumed. In thawing, the points are regularly spaced in triangular re- lation to each other 16 ft. apart between any two adjacent points. This establishes a fixed distance from the points to the supply line. Rubber hose is used only during driving, after which a standard pipe connection is pvt on. Between the pipe connec- tions and the main line ordinary railroad-train hose couplings may be inserted, obviating leaky unions and facilitating con- necting and disconnecting operations. Two pairs of point men, each equipped with an anvil, can drive five drill-bit points in 10 hours, viz.: Driving, 6 hr. ; pulling, 1^; connecting, 1^, and miscellaneous, 1 hr. Thawing Frszen Gravel by Hot Water. Engineering and Contracting, Oct. 18, 1916, gives the following: Marked reduction in the cost of thawing frozen gravel in the Klondike District has been brought about by the use of hot water instead of steam. In an article in the Sibley Journal of En- gineering for September Dr. Henry M. Payne states that during the season of 1915, by the employment of hot 'water and other improvements, the amount thawed per thawing point was in- 'creased 265%; the time required to drive the points was de- creased 50% ; the average net thawing period was decreased 50% ; the fuel consumption per unit thawed was decreased 65%; and the number of points used per unit area (and consequent labor- saving in driving and pulling) was 70%. During the past four years a systematic study of the thawing problem has been conducted by Dr. Payne, and the whole process has been reduced to a scientific basis. The actual temperatures, specific heats and specific gravities of the materials to be thawed have been definitely determined and several interesting physical characteristics discovered, as, e. g., it was found that after reaching frost line the temperature drops within the next few inches io the mean temperat. re of the mass, depending solely on the natuie of the material, and not on its depth or on water level. /V The steam points, instead of being driven in rectangular ar- rangement, are staggered in triangular lay-out, thereby reducing the theoretical unthawed segment between the thawed cylinders of ground, or the correspondingly necessary overlap to completely thaw the area. Experiments were carried on with hot water as a thawing medium instead of steam, the points being driven at varying 146 HANDBOOK OF EARTH EXCAVATION distances and depths, and left foi various periods and then A 7 ith- drawn, and excavations made to ascertain their efficiency. The great loss from condensation of steam was immediately corrected by this method, although the quantity of water re- quired is 3.0 times as much aa for steam at the same pressure, the boilers being supplied by injectors and the pipe line being connected with the blow-off pipe. The next steps were: The substitution of an Ingersoll-Rand drill bit point for the ordinary one on the steam point; the design and construction of a movable anvil to fit over the steam pipe at convenient driving height above the ground, eliminating the moving and climbing of ladders at each point while driving; the use of three-way connections on steam lines; and of standard pipe lengths and train-line couplings in place of rubber hose. Eventually the thawing point was driven to bedrock at one driving, and thawing started from the bottom up, instead of the reverse, as had always formerly been the case. Dredging Frozen Earth. Engineering and Mining Journal, May 26, 1904, contains a description of an elevator dredge. It worked all winter in Montana. Frozen sod 7 to 15 in. in thick- ness could be handled by the buckets without blasting, but when thicker than this it was broken by small charges of dynamite, about 1/2 sticks in a hole for every 10 sq. ft. of surface broken. The winter was mild and the frost was never over 24 in. thick. The sluice was made of sheet metal with an inner lining on sides and bottom of wood between which steam pipes were placed. Chisel Excavator for Frozen Ground. (Engineering and Con- tracting, Sept. 22, 1909.) A machine that was first used on sewer work at Winnipeg, Manitoba, for excavating frozen ground was operated as follows: A hole was first dug by hand through the frost, and then the machine was put to work chiseling down one side of the hole and elongating it into a trench. The ma- chine then traveled back and forth along one side of this trench, breaking down one side for several feet each trip, and so widening the trench until it covered the whole area. The operating force consisted of an engineer, a fireman, and four helpers. Briefly described, the machine consisted of a frame platform, mounted on a truck and carrying two hammer guides like the leads of a pile-driver. These leads were not fixed as in a pile- driver but were mounted on wheels, which ran on the top piece of a sort of gallows frame. They were thus capable of being shifted right and left a distance of 5 ft. each way. In the guides was an 800-lb. hammer, attached to bottom of which was a 6-in. diameter bar, from 3 to 7 ft. long, with its lower end forged down to a chisel edge. The drop of the hammer and LOOSENING AND SHOVELING EARTH 147 chisel was usually about 14 ft. At the center of the platform, just forward of the leads, was riveted a boom, whose outer end was guyed back to the top of the gallows frame. This boom made the machine a derrick for handling frozen lumps of earth excavated by the chisel. A 10-hp. engine and boiler operated the hammer and boom. The machine was invented by Mr. Wil- liam Hurst. In excavating a sewer in Winnipeg, the daily cost of operation was as fojlows: 1 Engineman at $3.00 $3.00 1 Fireman at $2.00 2.00 4 Laborers at $2.00 8.00 Coal and oil 3.50 Rental of machine 5.00 $21.50 The output on trenching work was about 60 cu. yd. per day, and on foundation work, from 200 to 300 cu. yd. per day. The work was done when the depth of frost was 5 to 6 ft., and -the cost of excavating a cubic yard by pick and shovel was $1.35. Using explosives, the cost has been in individual cases as low as 93 ct. per cu. yd. With machine, the same excavation costs from 11 to 30 ct. per cu. yd. Breaking Up Clay. A method of breaking up hard clay for a dredge somewhat similar to the foregoing is described in Engineering and Contracting, Feb. 12, 1908. The foundation walls for a bridge were sunk through sand and clay, the latter being dark blue and very hard. It was brittle when quite dry, but like leather when under water. A dredge was used to re- move the overlying sand but could, make no impression on the clay. Accordingly the following method of breaking up the clay was employed: Five double-headed rails each 20 ft. long, and weighing 64 Ib. per yd., were riveted together. The two outer rails were splayed outward like a trident and were sharpened. The center rail was also sharpened, and the two others were cut off at about 2% ft. from the end. This arrangement was worked up and down by a steam hoist, and, being top heavy, when it was driven into the clay it tended to fall over, thus breaking up the clay. In this manner a hole 1 ft. dee,p and 13^ ft. in diameter could be dug and dredged in 24 hrs. A Method of Thawing Ground for Trenching is illustrated in Engineering and Contracting, March 19, 1919, and is described as follows : In the construction of the Rideau River intercepting sewer at Ottawa, Ont., work was carried on during the winter months. As the frost penetrated deeply into the ground, the thawing 148 HANDBOOK OF EARTH EXCAVATION device shown in the sketch was employed. This consists of a box 6 ft. wide by 1 ft. high, and a steam pipe. The box was placed each night to cover a section of the proposed trench about 60 ft. in length the amount that would be excavated next day. The pipe had perforations every 18 in. The steam was kept on all night at high pressure. Z* ' Perforated Steam Pit* Trench to be Cut Fig. 27. Thawing Device for Frozen Ground. Boring Horizontal Holes Under Frozen Crust is described in Engineering News-Record, April 19, 1917, as follows: In steam-shovel excavation required in frozen ground on grade-crossing-elimination work at Mendenhall, Penn., the Good Roads Construction Co. did some experimenting in blasting the frozen crust. The results indicated that the most efficient method was to bore horizontal holes with an earth auger underneath the crust. The first attempt at blasting this crust was made by punching holes 4 ft. apart, with bars and hammers, through the 14- to 18-in. layer of frost. A quarter-pound of 60% dynamite was used in each hole, the shots being fired separately with a fuse and cap. It developed that the holes were too far apart and the powder too quick for this class of work, the tendency being to blow out small craters without loosening the entire crust. Du Pont low-freezing farm powder was then substituted and the holes placed closer together, on 3^-ft. centers. The loading was increased to i^-lb. per hole and electric firing adopted. This gave much better results, cracks extending from hole to hole, which enabled the steam shovel to take out the crust in chunks. The best results, however, were obtained after a face had been developed in front of the shovel by boring horizontal holes with an earth auger at the bottom of the frost line, loading them with % Ib. of farm powder each and firing them electrically. These holes appeared to confine the expanding gases better than the vertical holes and to secure the maximum heaving effect of the explosive. The crust was more thoroughly broken and the efficiency of the steam shovel increased by this method. LOOSENING AND SHOVELING EARTH 149 Blasting Frozen Ground with Gopher Holes. In overburden stripping on the Mesabi Range of Minnesota steam shovel opera- tions are continuous throughout the year. Much of the stripping is done during the winter months. The following description of the method commonly employed in breaking up the frozen ground is taken from an article by L. D. Davenport, Chief En- gineer Oliver Mining Co., in the Engineering and Mining Journal. Shallow holes, known as " top holes," are used* in stripping to break the frost. These are sunk with jumper or hand-drills that have been heated to a dull red; in badly frozen ground steam points have been used. The depth of the holes will vary from 3 ft. to 6 ft. The charge used in blasting consists of 6 Ib. Removable Box l?"xl?'xtf with Hopper Bottom - 1%'D/om. tto/e *n Bottom wifh wooden Plug Capacity l ~25lb. Black Powder Plan aes ...... ----5'- ---- - Fig. 28. Details of Loading Device for Gopher Holes. to 8 Ib. of du, Pont black powder per hole, depending on the ground. In some cases it is advisable to loosen the surface of the stripping for a considerable area by drilling holes 3 to 5 ft. deep and blasting with light charges of powder before the frost sets in. The air spaces in the ground thus loosened prevent hard freezing. Stripping banks 15 ft. or more in height are shaken up ahead of the shovel by blasting " gopher " holes. These holes are started at the toe of the bank and are pointed downward at angles of 5 to 10 from the horizontal. " Gopher " holing, when first used, consisted in making the holes large enough to permit a man to enter and work, but frequent accidents caused this method to be abandoned, and " gopher " holes at the present 150 HANDBOOK OF EARTH EXCAVATION time have an average diameter of about 15 in. Loose ground is removed with a No. 2 round-pointed shovel blade, the edges of which are slightly turned up, fitted with a 25-ft. handle of 2 or 3-in. diameter. When a hard seam is encountered, it is drilled with a long auger or with a moil, and one or two sticks of dynamite are pushed in with a pointed loading stick and fired with a blasting machine. The loose ground is then removed with the shovel. If a boulder is struck while the " gopher " is being driven, repeated blasting with 60% dynamite will often shatter it sufficiently to allow the hole to be continued. Where it is impossible to blast through a boulder, the hole is bottomed against it, or a new hole is begun a few feet away, depending on the length attained. The limit of length of a " gopher " hole is about 25 ft. In winter the top of the banks freezes as deep as 8 ft. Un- less this crust is broken by top drilling before " gopher " holing is done, the latter usually undercuts the bank, causing slabs of frozen ground to slide down and bury the loading track. It frequently happens, even where the frost has been broken, that chunks too large to be handled by the steam shovel roll from the bank to the track and have to be block-holed by drilling with a steam hose or hot moils and then blasted. The powder boss determined the size of the powder charge from the height of the bank and the material encountered in digging the hole. With a 25-ft. bank, 15 to 25 sticks of dyna- mite are vsed to "spring" or chamber the hole, which is then loaded with 5 to 10 kegs (25 Ib.) of black powder. Wooden spoons, 3 in. x 3 in. in cross-section, 2^ ft. long and fitted with 25-ft. handles, are sometimes used to place the powder in the holes. Long wooden launders 2 in. square with a hopper at one end, as shown in Fig. 28, are in general use. A keg of powder is emptied into the hopper, the cover shut and a plug closing the bottom of the hopper is pulled by means of a cord through the cover. The box is oscillated by a 12-ft. cross-handle, causing the powder to run down the launder into the chamber of the " gopher " hole. The long cross-handle allows the powder men to stand 6 ft. on either side of the hole, instead of directly in front, as was necessary with the old-style spoons. Furthermore, the closed hopper protects the powder from the danger of sparks. A detonator, consisting of 2 to 5 sticks of 60% dynamite with two exploders, is placed in the center of the charge. Two electric blasting caps, or else one electric and one ordinary blasting cap and fuse, are placed in each hole. The latter combination is in more general use for the reason that tamping sometimes injures the lead wires from the electric caps. Holes are filled and LOOSENING AND SHOVELING EARTH 151 tamped to the collar with sand or gravel and are fired in bat- teries of 3 to 5 at a time. The distance between holes is usually 20 to 25 ft., and the depth of the holes varies according to the shovel cut to bo taken. The general rule is to make the horizontal distance between the center of the loading track and the chamber of the " gopher " hole 5 or 6 ft. less than the reach of the shovel. For example, with a Model 91 shovel the distance from the center of the loading track to the bottom of the hole should be 40 ft., as the shovel reach from loading track to toe of bank is about 45 ft. Bibliography. " Handbook of Rock Excavation," H. P. Gillette. "Cost Data," H. P. Gillette. " Handbook of Construction Plant," R. T. Dana. " Earth and Rock Excavations," Charles Prelini. Monograph by C. Herschel on picking and shoveling, 1879. Bulletin 170, U. S. Department of Agriculture, Tractor Plowing. Eng. and Con., Aug. 20, 1913, Use of Augers for Boring Blast Holes in Clay. Eng. and Con., Jan. 20, 1915, Analysis of Con- crete Curb Construction. Eng. and Con., Oct. 18, 1916, Thaw- ing Frozen Gravel. CHAPTER VI SPREADING, TRIMMING, AND ROLLING EARTH Spreading. Trautwine states that a bankman will spread 5 to 10 cu. yd. an hour. Ancelin says 4.5 to 9 of earth, 3 to 8 of gravel, and 2.5 of mud is the average cubic yardage spread per man-hour. If the work is crowded, or not on a scale sufficiently large to warrant using a leveling scraper, estimate 7.5 cu. yd. spread per man-hour. On more extensive work, where a team can turn around, use a small leveling scraper; or, if there is abundance of room for turning, a road machine with three teams may be used. After dumping earth from slat-bottom wagons, each load in three piles, I have used a small leveling scraper, which with one team and driver and a helper will spread 50 cu. yd. per hour. Three teams with a driver and a helper on a road grader will spread 90 cu. yd. of earth an hour from piles left by dump- wagons, spreading the earth in 6-in. layers. Thus the cost will vary from 2 cts. per cu. yd. by hand labor to i-ct. by a small leveling scraper. See Chapter IX for illustrated descriptions of leveling scrapers and road graders. Cost of Grading and Trimming an Athletic Field. D. J. Hai.er, in Engineering and Contracting, Jan. 9, 1907, gives the following : The work consisted of exeavating 400 cu. yd. of earth from one corner of the field using it to fill up some low places, and in making a small running track, 0.2 mile long. The excavation covered an area of 20,000 sq. ft. and the places over which the earth was dumped were of the same area. The work was to be finished in 18 days after starting, but owing to the fact that on 14 of these days rain fell, it was not finished on time, and the wet weather added somewhat to the cost. Every mark of a cart wheel and a man's foot had to be effaced from the ground. The work was done by contract in the spring of the year. The \va<,es paid for a 10-hr, day were as follows: Laborers $1 .25 Cart and driver 2.25 One-horse roller and driver 2.00 The contractor took direct supervision of the work. The work, listed under the following heads, cost: Ditching: Labor $ 5.87 Tiles 5.25 $ 11.12 152 SPREADING, TRIMMING, AND ROLLING EARTH 153 Excavation: Labor v $133.13 Hauling ,...'.' 91.75 224.88 Trimming and finishing: Trimming $ 36.50 Raking 6.50 Rolling 12.00 55.00 Total $291.00 The ditches were only a foot deep, and a man excavated and backfilled 8.4 cu. yd. per day at a cost of 15 ct. per cu. yd. For the excavation the earth was loosened by a plow, two of the cart horses being used for this purpose when needed, the greater part of the plowing being done after the men quit work for the day. One-horse carts were used for hauling, there being a driver to each cart. The cost of loosening with pick and plow and of the loading as well as dumping was 33 ct. per cu. yd. at the wages paid; for wages of $1.50 per day the cost would have been 40 cts. The hauling cost 23 ct., but the wages of hired carts were low compared to those paid to-day. Finishing. The finishing consisted of three items, trimming, raking and rolling. The raking and rolling were done on the embankment, the trimming where the excavation was made. The embankment was leveled with shovels as it was made, and then rolled, after which it was raked with steel rakes and then given a final rolling. This cost 0.8 ct. per sq. yd., or 4.6 per cu. yd. of excavation. The trimming was done with mattocks and square-pointed, short-handled shovels. Not more than an inch or two had to be dug and the greater part of the dirt was used to fill small holes. The work had to be done carefully and levels were run over it to see if it was to the proper grade. The cost was 10.7 ct. per cu. yd., or 1.6 per sq. yd. Each man trimmed 78 sq. yd. per day. Surfacing and Dressing Earthwork. On contracts for earth excavation the matter of dressing up and surfacing, both of the place excavated, and of the place of depositing the earth, should be given more consideration than it usually gets. Plans and specifications for this work should be included among those furnished the contractor at the time of bidding. Frequently, there should also be a bidding item for " surfacing." On wagon road work the dressing and surfacing is sometimes a large per cent of the total cost. On railroads and large embankments if the work is properly managed the cost of dress- ing should be a very small part of the cost. 154 HANDBOOK OF EARTH EXCAVATION Contractors should impress this fact upon their foremen and put into the hands of their foremen, hand or Locke levels, in- structing them as to their use, so that all cuts can be taken to grade, and embankments carried to their full height, including shrinkage, as the work is being done. A hand level will be found of vast assistance in this. If levels are to be run over the finished work, leveling should be done frequently while it is in progress. This may save a lot of costly surfacing. Trimming. Gillespie says that a man will trim 11 sq. yd., or about 100 sq. ft., surface measure of embankment per hr. The writer is inclined to think that Gillespie's estimate of cost is altogether too high; for a man can pick and shovel 2 cu. yd. of embankment an hour, at which rate he would be able to "trim" to a depth of 6 in. if he covered only 11 sq. yd. of surface per hr., whereas trimming, " smoothing," or " sand- papering " requires a moving of about 2 in. of earth instead of 6 in. From several careful observations the writer has found that a f^ang of men under a good foreman will each trim the sod and humps off the hard surface of a cut to the depth of 1 or iy 2 in. at the rate of 200 sq. ft. or 22 sq. yd. per hour, at a cost of 73-ct. per sq. yd.; and where there was no sod to remove, the soil being sandy loam, the cost was one-half as much or %-ct. per sq. yd. Prior to the world war, Massachusetts contractors bid almost uniformly 2 ct. a sq. yd. for "surfacing" (wages 17 ct. per hour), which includes rolling the finished surface with steam roller. A roadway, including ditches, 36 ft. wide and a mile long, has 21,000 sq. yd. of surface, which at %-ct. is $140, actual cost of trimming. If the total excavation in a mile is 3,500 cu. yd. (which is about the average in N. Y. State), the cost of trimming, distributed over this 3,500 cu. yd., is 4 ct. per cu. yd. of excavation, a cost much greater than a mere guess would lead one to expect. If " sandpapering " is specified, it is evident from this that the item of trimming must not be overlooked; and the shallower the cuts, the greater its relative importance as an item of cost. A leveling scraper, a road grader, or similar tool will do the trimming of comparatively flat surfaces that are over 6 ft. wide for a very much less sum than by the shovel and mattock method; in fact, the cost is so slight, being merely nominal, that it may then be entirely omitted from the estimate. The author has directed the scraping of a light growth of weeds and grass off the 4-ft. shoulder of a road by going once over it with a "Twentieth Century grader" (a small leveling scraper), at a SPREADING, TRIMMING, AND ROLLING EARTH 155 rate of 200 sq. yd. per hr. or ten times faster than a man with a mattock would have done it; making the actual cost about i^-et. per sq. yd. where the team, driver and helpers' wages were 50 ct. per hr. As illustrating both poor design and poor management, the Forbes Hill Reservoir experience may be referred to; for very often contractors are compelled by specifications to do just such needlessly expensive work as the following done at Forbes Hill: " In order that the portion of the banks near the inner slope might be rolled as thoroughly as other portions, the bank was built with an extra width of 1 ft. and afterward trimmed to grade." In trimming, the slope of the bank (hardpan rolled) was first plowed, and the material was cast down to the bottom with shovels. The final trimming was done with picks and shovels. Labor cost 15 to 17 ct. per hr. ; teams 45 to 50 ct. ; and 1,500 cu. yd. were thus trimmed off. The loosening cost 56 ct., and the loading into carts 30.6 ct. per cu. yd., or a total of 86.6 ct. for loosening and loading each cubic yard of earth! A contractor cannot be too careful in examining specifications for reservoir embankments before bidding. Cost of Trimming and Dressing Frozen Ground. Engineering and Contracting, Jan. 29, 1908, gives the following: About 1,500 ft. of roadbed had to be dressed up to allow track to be laid at once. At the time the work was done the ground was frozen to a depth of about one foot. Naturally this added much to the cost. The wages paid were: Foreman, $3.50; laborers, $1.50, and cart and driver, $2.50 for a 10-hr, day. From 14 to 18 men worked in the gang and while the ditches were being dug two carts were used, but after the bulk of the earth was moved only one cart was kept on the work. The cost was: Foreman, 9% days $31.67 Laborers, 145% days 218.25 Carts, 15 days 52.50 Total $302.42 There was 3,200 sq. yd. of surface to be trimmed. About 2,300 sq. yd. were in the cut and the rest was on the embankment. Only a few places on the fill had to be cut down; the low places being raised with the material from the cuts. The cut was within a few inches of grade throughout, only about 100 cu. yd. being taken out of it, making an average of about 1 in. to be trimmed off the surface. From the ditches 133 cu. yd. were excavated. The cost per sq. yd. of surface dressed was as follows : 156 HANDBOOK OF EARTH EXCAVATION Foreman $0.010 Laborers 0.068 Cart 0.016 Total $0.094 Thus the cost was between 9 and 10 ct., when it is frequently done for 1 ct. per sq. yd. on railroads. From this it will be seen that each man trimmed and dressed 22 sq. yd. per day. Under favorable circumstances he would do about six times as much. Outside of the work in the ditches, only a small piece of the earth could be chipped off the frozen ground at a time. In the ditches picks could be used to ad- vantage, but on the roadbed it was necessary to cut off the few inches of earth with mattocks. Even then it took 10 to 12 pickers to keep three or four shovels busy loading the material into carts. The total cost per cu. yd. of material so moved was $1.30. One man loosened and shoveled in a day about 1% cu. yd. These figures show conclusively how expensive this class of work becomes when the ground is frozen. The original cut was shallow, the total yardage in it being about 2,000. Thus the cost of trimming and dressing distributed over the yardage of the cut, makes a cost per cu. yd. of 15 ct. Trimming a Subgrade. Engineering News, June 18, 1903, gives the following: The grading was done with drag-scoop scrapers, wheel-scrapers and wagons, each being used as de- manded by the length of haul. Earth was loosened with plows to within 3 in. of subgrade and this last layer then removed with pick and shovel. The cost of removing the last 3 in. was 2 ct. per sq. yd. with labor at $1.75 per day of 10 hr. Trimming and Seeding Slopes. Engineering News, Oct. 19, 1916, gives the following: A traveling derrick with skips was used in clearing a long cut on the Baltimore & Ohio R. R. near Muirkirk, Md. The north side of the cut for about 2,500 ft. had been badly gullied, and the material washed down had clogged the track ditch. The cut is about 30 ft. deep. At the top of the slope was installed a derrick car consisting of a timber plat- form or truck mounted on four wheels and carrying a boiler, a 15-hp. double-drum hoisting engine and a stiff -leg derrick with 30-ft. boom. This car ran on a wide-gage track, which was picked up in the rear and relaid ahead as the work progressed. The material excavated was loaded into open flat boxes of 12 cu. ft. capacity, which the derrick raised and dumped to form a broad flat fill about 4 ft. from the top of the cut. This bank serves to stop drainage toward the cut and renders a top ditch unnecessary. The ditch was cleared out and the slope dressed SPREADING, TRIMMING, AND ROLLING EARTH 157 to a uniform surface. The slope was then covered with street sweepings and sown with grass seed to form a permanent pro- tective covering. The force and organization were as follows: 1 foreman, 1 engineman, 16 men trimming the slope and filling the boxes, 1 or 2 men at guy lines to guide the loaded boxes up the slope and haul the empty boxes back into position, 1 man at the top of slope to trip the boxes and spread the ma- terial in the fill, 2 men shifting track, 1 cart and driver to haul coal and water, 1 water boy, 1 night watchman. This force co Id handle about 400 boxes per day. The cost was less than 60 ct. per yd. For seeding the slopes a mixture of alsike clover, blue grass, alfalfa and oats is used. After seeding, the surface is covered with about 6 in. of street dirt or street sweepings from the large cities, this being shipped in cars and distributed by teams and men with wheel-barrows. This method has been found very satisfactory, and after the first season it is easy to maintain the slopes. Ramming and Rolling. A man can thoroughly ram or tamp in 6-in. layers 2.5 cu. yd. per hr. ; but where the soil is not clayey, consolidation may often be more effectually and cheaply done by puddling with water. A 5-ton roller with a 60-in. face, drawn by three teams handled by one driver, will consolidate about 100 cu. yd. an hr. One team on a 2-ton grooved roller will travel ten times over a 6-in. layer at a speed of 90 ft. a minute including rests, thus consolidating at a cost of about 1 ct. per cu. yd. where team and driver wages are 70 ct. per hr. As an example showing the highest probable cost of spread- ing and rolling a reservoir bank where extraordinary care is required, the Forbes Hill Reservoir, described by Mr. C. M. Saville in Engineering News, May 13, 1902, may be cited. The material was hardpan (clay and gravel) spread in 4-in. layers by hand, all cobbles over 3 in. in diameter being removed. The sprinkling was done from a water pipe and hose. Corrugated rollers weighing two short tons each, and drawn by two horses, were used. Laborers were paid 15 ct. to 17 ct. per hr., team (and driver) 45 to 50 ct. The dumping of wheel-scrapers and spreading by hand cost 7.7 ct. per cu. yd.; and the rolling cost 3.9 ct. per cu. yd. measured in cut. There is evidence, however, indicating poor management in doing this work. In reservoir embankments, harrowing may be required^ in which case a team and driver upon a harrow may be counted upon to harrow about 100 cu. yd. an hr. Sprinkling. Sprinkling of embankments, where specified, is usually required to be " to the satisfaction of the engineer " a 158 HANDBOOK OF EARTH EXCAVATION form of wording that always seems like an attempt to hide ig- norance under a cloak of ambiguity. Seldom should more water be required than would fill the voids in the packed earth, say 8 cu. ft. of water per cu. yd. of earth; and as a rule not over half as much as required 'to secure satisfactory pud- dling. On a large embankment three sprinkling carts, each drawn by three teams, with one driver, sprinkled 1,000 cu. yd. of earth per day of 10 hr., with short haul. Such carts each held 150 cu. ft. of water weighing 4.5 tons, which is an exceedingly large cart. A sprinkler of this capacity can be loaded from a tank in 15 min., and emptied in the same length of time. Knowing the length of haul and speed of team the cost of sprinkling is readily determined. In the case just given the cost was 2.3 ct. per cu. yd. of earth for sprinkling and about 5 cu. ft. of water per cu. yd. were used. A man with a good hand pump will raise 1,000 cu. ft. of water 1C ft. high in 10 hr. into a tank, making the cost of pumping in this case by five men for the 1,000 cu. yd. of earth sprinkled, 1.5-ct. cu. yd., when wages are 30 ct. per hr. Had a small engine burning ^/2 tn soft coal a day and an engineman been employed, the cost would have been about half as much for the pumping item. Cost of Spreading and Rolling a Reservoir Embankment. The Tabeau Dam in California is an earth embankment 100 ft. high, containing 370,000 cu. yd. of embankment. Mr. Burr Bassell is authority for the following: The earth (a clay mixed with gravel) was spread in 6-in. layers, sprinkled and rolled. To spread the 2,000 cu. yd. of embankment daily, there were 3 road graders operated by 6 horses and 2 men on each grader. There were 2 rollers, each operated by 6 horses and one driver. There were 2 harrows, and, while Mr. Bassell does not so state, presumably 4 horses and a driver to each harrow. At $1.50 per 10-hr, day for each man and $1 for each horse, we have following cost: Per cu. yd. ct. Spreading 1.5 Sprinkling 0.8 Harrowing 0.6 Rolling 0.8 Total 3.7 Loading and hauling - 32.3 General expense (estimated) Plant charge (estimated) ...,..;: '! ,j ; .,i . ^.nUi'n.jv' Total .. v . -.,...>.,..,......... ^ ...j.y^i.^Yftj, 39.0 SPREADING, TRIMMING, AND ROLLING EARTH 159 Test pits dug in this dam showed a weight of 133 Ib. per cu. ft. of compacted earth. The above given yardage relates to the yardage in the em- bankment, not in the barrow pits. The rates of wages are merely assumed for illustration. It is probable that laborers received $2 per day at that time and place. Smoothing and Leveling Farm Land with Tractors. Engineer- ing and Contracting, June 12, 1918, describes some experimental work that has been done by the Reclamation Service on the Truckee-Carson project. Land that is too rough to be irrigated by the "' boarder-check " system of irrigation is being roughly leveled for this purpose, its final leveling being left to the farmer. For use with this system of irrigation the land is divided into strips by building low wide parallel levees running with the slope and 60 to 70 ft. apart. The slope of lands between levees, where soils are light, should not be less than 0.2 ft. per 100 ft.; on heavier soils about 0.1 ft. per 100 ft. is allowed as a mini- mum. The length of strips is from 330 to 660 ft., depending on topography and the economic arrangement for farm laterals and for the removal of surplus irrigation water. Before work of rough leveling is started a topographic survey is made of the tract. This is used in part to determine the posi- tion of the main and lateral ditches and drains, but mainly to determine the direction of slope to be given the lands that are to be leveled. Where the general slope is hard to determine with the eye, 0.5-ft. contours should be taken, when the slope is more pronounced intervals of 1 ft. are ample, and where the tract as a whole has a pronounced slope 2-ft. contours are sufficient. In preparing a farm unit for rough leveling the prevailing slope, possible water surface elevations and the ditch and drain- age system should all be considered. After these factors have been determined roughly, and the farm is plowed to agree with the general scheme of the tract, a line of levels is run around a 5, .10 or 20-acre part of the unit, the size of the tract depending on the general slope. Stakes are then set at the lower and upper end of the land as guides for the tractors' doing the leveling. The land is plowed first, but not disked. The sod crumbles under the weight of the equipment, and as the shaping of the land progresses the lumps disappear. In fact, sandy lands do not need to be plowed at all. The land is generally divided into squares or rectangular strips arranged so as to give the minimum ditch length. The final leveling and shaping of the land is done 160 HANDBOOK OF EARTH EXCAVATION by the farmer at the time the levees and ditches are constructed. This work is usually done with fresno scrapers. During the summer of 1917 two tractors were operated, mainly as an experiment and to determine the costs of preparing the land. A flood-lighting system has been devised for working the machines 24 hr. per day. If this proves to be practical, it will be possible to level about 500 acres per month, or about 300 acres if the tractors are worked only 16 hr. per day. The two machines have worked 16 hr. nearly every working day through the season. The average amount of rough leveling has been 126 acres per month, including all lost time. The average cost has been as follows: Per acre Operation of plant and equipment $18.50 Depreciation of plant and equipment 5.00 Engineering 1.50 General expense 3.75 $26.75 To this must be added the $6 per acre for plowing, making the total cost $32.75 per acre. This includes several plowings on some land. In the tract where work is being done there are thirteen 80- acre units. Some leveling has been done on nearly every unit. As the remaining acreage is noticeably rougher than that leveled, we assume that when the tract is done the average cost will be about $40 per acre. So far the tractors have worked only on unentered public lands. The leveling of uncultivated settled lands has been considered, but no. decision has been reached; In fact, the terms at which the Government will require the return of the cost for rough leveling have not yet been determined. Smoothing Devices Used in Preparing Land for Irrigation. These are described in Engineering and Contracting, Jan. 31, 1912. In preparing land for irrigation it is essential that even the smallest irregularities be smoothed down so that an even dis- tribution of water can be obtained. The land is not necessarily leveled but is graded to an even and continuous slope. Fresno scrapers are used on this work, but home-made leveling devices are preferred. Rectangular Leveler. Fig. 1 shows a leveler commonly used in California. It is a heavy tool requiring from eight to ten teams to haul, but it will cut down small hummocks, removing shrubs, roots and all. It is solidly built of 4 by 12-in. timbers. One cross-piece is arranged to move up and down by means of a lever, so that the entire weight of the machine can be thrown SPREADING, TKIMMING, AND ROLLING EARTH 161 on it for cutting down hard knolls. All of the cross-pieces are shod on their faces with % by 6-in. steel plates. Heavy chains and eveners are employed to hitch the teams to the leveler, and these are of considerable service in breaking down any shrubs that may be growing on the land. Altogether the weight of this leveler is not far from a ton, including the driver and lever Fig. 1. Rectangular Leveler for Heavy Grading. operator, both of whom ride on the machine. The rectangular leveler does the best work where the knolls are regular in size and position. Such lands are commonly worked over in bands or strips a half-mile to a mile long and 300 to 1,000 ft. wide. Modified Buck Scraper or Planer. This devke shown by Fig. Fig. 2. Planer for Smoothing Graded Land. 2 is designed particularly to give the finishing grade following the rough grading done with scrapers or with the rectangular grader, Fig. 1, hence the name planer. It is L-shaped in sec- tion, being made up of a horizontal 4 x 12-in. plank 14 ft. long and a back board of 2-in. plank 18 in. high. The bottom and back are bound together by the steel plate with which the base 1(32 HANDBOOK OF EARTH EXCAVATION is shod and by strap iron brackets. The front edge of the base plate is beveled to a cutting edge. The back board is 1 ft. shorter than the base at each- end to provide for the standing boards on which the drivers ride. There are two drivers each handling a four-horse team hitched to each end of the base. By throwing their weights onto the front or rear ends of the foot boards, the cutting edge is tilted down or up to shave off a layer of earth, or to ride over and distribute the soil smoothly. The whole manipulation of the planer, including turning, is easy. As ordinarily used the planer follows the rough grader shown in Fig. 1. When the grader has uprooted and removed the brush and major irregularities, the planer is employed to do the final "Wig. 3. Grid-Iron Drag for Heavy Grading. smoothing. Records of work in California give the cost of re- moving brush and hummocks by the rectangular grader as $1 to $1.20 per acre; the final planing costs from $1 to $1.50 per acre more, making a total cost of $2 to $2.75 per acre for com- plete grading. Grid-Iron Grader. Fig. 3 illustrates a home-made grader used in Montana. The outside longitudinals or runners are 16 ft. long and are made up each of two 2 x 6-in. pieces set one higher than the other as shown by the detail drawing. Between these run- ners and running across the grader are set eight 2 x 4-in. pieces which are shod with steel plates to form scrapers. The inclina- tion of the 2 x 4-in. scrapers is t5 be noted ; also the intermediate longitudinals and the diagonal bracing. SPREADING, TRIMMING, AND ROLLING EARTH 163 Wheeled Planer. For smoothing the ground after grading the device shown by Fig. 4 is an approved tool. This is also, a Mon- tana device. The main structural features are shown by the drawings; it may be noticed, however, that the frame is raised about 14 in. by the wheels and that the scraper blade is steel Fig. 4. Wheeled Leveler for Smoothing Graded Land. shod. This planer is hauled by three to four horses and under competent handling will level from 10 to 20 acres of graded land per day. Bulletin 145, Office of Experiment Stations, gives the average cost in Colorado and Wyoming of preparing land for irrigation as follows: 164 HANDBOOK OF EARTH EXCAVATION Item Per acre Grubbing sage brush $1.50 Plowing 2.50 Harrowing 0.50 Grading 1.00 Total $5.50 Bibliography. "Cost Data," H. P. Gillette. " Highway En- gineer's Handbook," Harger and Bonney (Data on Spreading and Rolling). Bulletin 145, U. S. Department of Agriculture, Preparing Land for Irrigation. Eng. News., April 28, 1901, C. R. Coultee on method of compacting lumpy clay on Soulanges Canal. jti CHAPTER VII HAULING IN BARROWS, CARTS, WAGONS AND TRUCKS In selecting the most economic method of hauling earth over roads, the size of the job and the length of haul are two of the most important factors. There are so many other factors that little is to be gained merely by enumerating them. Perhaps the best way to secure an insight into the problem is first to con- sider each of the different kinds of plant used in hauling, to- gether with the respective methods and detail costs. Lead and Haul. The " lead " is the distance between the cen- ter of mass of earth in the " cut " or pit and the center of mass of the embankment. The " haul " the distance actually traveled in moving the earth from " cut " to " fill " or embankment, measured one way. The haul is half the round trip distance, and is often considerably greater than the lead. Types of Wheelbarrows. Engineering and Contracting, Dec. 30, 1908, gives the following: There are many styles of barrows made for different classes of work. Those used on earthwork are of the tray pattern. The frame is usually of wood or of a Fig. 1. Wood Tray Wheelbarrow. Fig. 2. Stave Tray Wheelbarrow. 165 100 HANDBOOK OF EARTH EXCAVATION combination of wood and steel, wheels are of wood or steel from 15 to 21 in. in diameter. Large wheels make the barrow easier to propel. Steel wheels are preferable to wooden wheels on ac- count of their greater durability. The trays are made either of wood or steel. When only earth is being handled steel trays are Fig. 3. Steel Tray Wheelbarrow. to be preferred, as the trays do not sift the dirt over the run- ways, and the dirt dumps easier, especially if wet. When there is much rock in the excavation the wooden trays give better service and are more economical. They get out of order more easily than the steel trays but are easily repaired. They are not HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 167 so apt to be bent out of shape from rough handling, and for that reason are superior to the steel for handling rock. All-steel tubular barrows are made, the entire barrow and running gear being of steel. They are too heavy for earth exca- vation. Such barrows weigh from 70 to 125 lb., while steel trays on wooden frame or running gear weigh from 55 to 70 lb. and the wooden tray barrow weighs from 40 to 60 lb. Runways of the same kind should always be used for wheel- barrows. The common practice for level short hauls is to lay 1-in. planks on the ground with their ends butting together. Where one man only has to wheel a barrow over the runway, and the planks are changed frequently, such a runway is eco- nomical and answers the purpose very well, but when a number of barrows are to go over the runway the ends of the boards should be nailed to a small sill sunk into the ground, so as to prevent the boards from being knocked out of place. Good run- ways quickly pay for themselves, as to delay a long line of barrows only a few minutes, to straighten out or repair a run- way, means to waste considerable money. Where runways are not laid directly on the ground, but are elevated, 2-in. planks should be used, and the runway should be at least 24 in. wide. They should be substantially built, so that there is no motion or swaying to them, as the men wheel over them, or else the barrow pushers will slacken their pace; this is especially true when going on an incline. Steep inclines that are short, men go up easily, but long inclines, though not so steep as short ones, men push their barrows up slowly. In either case a strongly built runway is needed. To obtain good work men must be made to believe they are safe from injury while at their work. A Barrow with Special Dumping Device is described in En- gineering and Contracting, Jan. 15, 1913. A wheel barrow which is dumped by pushing down on the handles and with half the work, it is claimed, that is expended in lifting the barrow in dumping by the ordinary method is illustrated in Fig. 4. The barrow calls for little description. When loaded, the steel body rests on the frame in virtually the same position in respect to the wheel and ^handles as does the body of the ordinary barrow. It can thus be dumped like an ordinary wheel barrow by tipping sidewise or by lifting the handles and dumping over the front edge, or it can be dumped as shown by the illustration. In dumping by pushing down on the handles it is easy to regulate the outflow to a thin stream in filling narrow forms or by a quick downward thrust to dis- charge the whole load suddenly. This barrow is known as the 168 HANDBOOK OF EARTH EXCAVATION Long Self-Dumping Wheelbarrow and is sold by Miller & Coulson, Pittsburgh, Pa. Costs with Wheelbarrows. Barrows are not economic except in muddy places where horses would mire, or in narrow confined places, or in moving very stony soils short distances, or where the quantity of earth is small. Trautwine assumes that a man will load and dump a wheel- barrow in 1.25 min., the barrow holding i/ 14 cu. yd., and that a man will travel 200 ft. a minute. He further allows 10% " time lost " in rests. His tables of cost are about right for hauls of ordinary length, such as a 100-ft. haul, but 'are grossly Fig. 4. Long Self-Dumping Wheelbarrow. in error for short hauls, as for 25 ft., where, by his false as- sumption that a barrow can be loaded in 1.25 min., he makes an output of 25.7 cu. yd. in 10 hr. per man, the actual output being not much over half as much. The error arises from a short-time observation where insufficient time was allowed for necessary rests. From careful observations the author has found that a man walks at a speed of 250 ft. a minute, and loses % min. each trip, dumping load, fixing run plank and resting; and that it takes 2.25 min. to load a barrow holding 1/J 5 cu. yd. place measure of earth already looseried (rate of loading being 1.8 cu yd. an hr.), and in this the author is confirmed by Cole's observations (see Gillespie) on the Erie Canal. Wherever the word "haul" is used, the distance, one way, from the point of loading to the point of dumping is meant. In repairing breaks in a levee where the material was very HAULING IX BARROWS, CARTS, WAGONS, TRUCKS 160 sticky adobe clay, Mr, Specht made the following observations as to cost: Haul 208 ft., rise 7 ft., load in wheelbarrow ^ cu. yd., 7.5 min. per round trip; output per Chinaman on wheel- harrow, 10.8 cu. yd. in 9.5 hr. of actual working time. 10 Chinese on wheelbarrows, at $1.50 $15.00 3 Chinese a $1.50 4.50 1 White foreman 2.50 108 cu. yd. per day at 20.4 ct $22.00 It will be noted that the load of a wheelbarrow given by Specht is double that ordinarily given. The author believes it to be misleading, since } cu. yd. of clay would weigh 350 to 400 lb., and not even a Chinaman would move such a load as that day in and day out. Based upon the data given in this and pre- ceding chapters we have: Rule. To find the cost per cu. yd. of picking, shoveling, and hauling average earth in wheelbarrows, multiply the wages of a laborer per hr. by one and one-sixth and add one-third of an hr.'s wages for each 100 ft. of haul. When wages are 30 ct. per hr. this rule becomes: To a fixed cost of 35 ct. add 10 ct. for each 100 ft. hauled. Capacity of Wheelbarrows. Mr. James H. Harlow (Engineer- ing News, Sept. 21, 1905) found, when removing earth filling from one cofferdam and placing it in another, that 7,959 bar- row loads held 454 cu. yd. by measurement, or 0.057 cu. yd. or 1.54 cu. ftrper barrow. This material was a sandy loam weigh- ing 80.3 lb. per cu. ft. When removing gravel from a bar at Davis island, he found that 23,484 barrow loads equaled 1,228 cu. yd. by measurement, or 0.0546 cu. yd. or 1.47 cu. ft. per barrow. Wheelbarrows Loading into Cars. At Portland, Oregon, in 1883, a large bluff was excavated at the rate of 153,000 to 183,000 cu. yd. per month by wheelbarrows and horse-scrapers loading into cars. This work is described in an illustrated article by Mr. George B. Francis in Engineering News, Nov. 28, 1885. Two platforms each 700 ft. long and 40 ft. wide were built par- allel with the foot of the bluff. Beneath each platform were two standard gage tracks on which flat cars with side-dump boxes were drawn by locomotives; each car held about 6 cu. yd. place measure. The material was dumped into the cars through holes 20 in. square. The earth was loosened and thrown down the slope by blast- ing with Judson powder on the top and slopes of the bluff. On one platform 600 Chinamen with wheelbarrows loaded the cars, and on the other horses and scrapers. The rivalry between these gangs resulted in efficient work. 170 HANDBOOK OF EARTH EXCAVATION The first month, when part of the earth was dumped into water, the material shrunk 10% from place measure to measure in the fill; the second month 8%, and the first 41<>,000 cu. yd., 3.4%. Cost of Wheelbarrow Work at the Albany Filter Plant. Mr. Geo. I. Baily, in a paper read before the American Water Works Association in 1901, gives the operating cost of the Albany Filter Plant. He states that the ordinary wages of $1.50 per day of 8 hr. was paid but that efficient work was insisted upon. " A part of the success is due to the attention which we have given to details of the work. We have endeavored to improve not only the work of the men and to simplify it, but to furnish them suitable tools. On the start for scraping we i sed the ordinary straight edge, D-handle shovel. We learned that it lamed the backs of our men and they could not work to ad- vantage. We abandoned these shovels for long-handled shovels, which would allow the men to keep in a more erect position, and to overcome the slower handling of the new shovel we widened the blade to 12-in., and with these shovels our men scraped more than 100 sq. yd. an hr. " In the running plank used for wheeling out scraped material we found that to give a proper foundation and width we had to use two of the ordinary 10- to 12-in. planks, and then the service was not good. W T e had planks specially sawed 14 in. in width, and one of these planks answers the purpose better than two of the others. They are placed as speedily as one of the other planks and the time is therefore reduced one-half. The ordinary wheelbarrows used were not acceptable. On the grades that our men had to go the weight was shifted on the men's arms instead of being carried on the wheel and we therefore re-adjusted on the wheels, giving a proper distribution of weight and saving the strength of our men." Comparative Cost with Wheelbarrows and Carts. In exca- vating for the filter bed at Brockton, Mass., wheelbarrows and one- and two-horse carts were used. The comparative cost of these vehicles is given in Fig. 5. In many cases the haul was up an incline and it was found that in wheelbarrow work a lift as great as 5 ft. per 100 made no apparent difference in cost. The time taken in returning with the empty wheelbarrows was 60% of the total time occupied per round trip, which proved that the work was under the direction of inefficient foremen. The cost of spreading earth on the embankment amounted to 0.75 ct. per cu. yd., and is not included in the diagram. Wheel- scrapers were not used very often, as the number of roots left in the ground after grubbing, and the necessity for removing HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 171 them from the embankment material, precluded their use. When wheelscrapers could be used the cost of hauling 125 ft. varied from 5 to 6 ct. per cu. yd. About 15 cu. yd. per man per day were handled. One fore- man was employed to each 16 shovelers. Length of Houl in Ft c 9 $8 Average Number of Men Loading OneHone Carts = X n 11 n t 7*0 s Teamster $?.oo IHorse % , 2S Laborers (G> $1,50 Wheelbarrows cany ? cu. ft One Horse Carts /5~ 7&0 v 5" " "i Extra bood Digging. (Small Load) Fig. 5. Relative Efficiency of Wheelbarrows and One and Two- Horse Vehicles in Moving Earth on Brockton Filter Beds. Excavating Earth and Hardpan for a Creek Change. En- gineering and Contracting, Aug. 19, 1908, gives the following: The work described was the changing of the channel of a small creek in the Cumberland Mountains, in connection with the construction of a new line of railroad. The located railroad 172 HANDBOOK OF EARTH EXCAVATION crossed the creek twice within 300 ft. and to make a diversion of the stream meant the saving of a 20-ft. arch culvert. The new channel was made 20 ft. wide on top, 15 ft. on the bottom and had an average depth of 6 ft. It was about 250 ft. long. The top 2^ ft. was a sandy .clay, while the rest of the material was a hard cemented gravel. This had to be blasted before it could be shoveled. The blasting was done with dynamite, holes being put down in the gravel in series, being spaced 5 to 6 ft. apart, and about 15 holes shot at one time, with a battery. Picks were then used to loosen the material. Under the specification cemented gravel was classed as loose rock, and the engineers classified the excavated material as 400 cu. yd. of earth and 600 cu. yd. of loose rock, there being in all 1,000 cu. yd. of excavation. The excavated material was placed in an adjoining embankment, the earth being loaded onto wheel- barrows. The haul averaged 50 ft. Boards were used as run- ways. When the work commenced a man loaded a wheelbarrow and pushed it to and from the dump, but, as the trench became deeper, one man stayed in the trench and loaded the barrow, while another operated it. However, as two barrows were used, one being loaded while the other was going to the dump, it meant a wheelbarrow for each ' man. Cost of Excavation. The total cost of the work amounted to the following: Foreman, 22 days, at $3.00 $ 66.00 Laborers, 188% days, at $1.25 235.63 Blasting 47.68 Total $319.31 The average cost per cu. yd. was: Foreman . . .' $0.066 Labor, loosening, shoveling and wheeling , ... 0.236 Blasting: Labor 0.025 Explosives 0.022 Total $0.349 The cost per cu. yd. for each class of material excavated was as follows, being a comparative cost to the price paid for each class of excavation: Earth: Foreman $0 042 Labor '. 0.14$ HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 173 Blasting: Labor $0.015 Explosives 0.013 Total $0.218 Loose rock or hardpan: Foreman $0.083 Labor 0.297 Blasting: Labor 0.031 Explosives 0.026 Total $0.437 One man loosened, loaded and wheeled 5^4 cu. yd. per day, which is a fair day's work in this class of material and under the conditions named. Two valuable lessons are to be learned from this job. The first is a lesson for the contractor. This excavation should never have been made by hand, but instead teams with drag scrapers should have been used. This work could have been done cheaper with drag scrapers, even if they had to be bought new and their entire cost charged against this job. It would have been cheaper yet to have dammed up the old channel and excavated a ditch 8 to 10 ft. wide, just room enough for scrapers. The stream could then be turned into this ditch and would widen it to the required size by natural erosion. Cheaper material than cemented gravel could have been borrowed for the embankment. " Station Work " on a Railway Embankment. Wilmer Waldo, in Engineering and Contracting, Dec. 4, 1907. " Station work " is excavation that is let in small contracts, covering one or two surveyor's " stations " of 100 ft. in length. A contract is usu- ally taken by one or two laborers in a gang. Embankments are built of material taken from either side of the right of way at a distance of 4 or 5 ft. from the toe of the fill. No fur- ther restriction is made concerning borrow pits except that they must be connected by ditches for the sake of drainage. " Station work " is usually done in places inaccessible to teams or where stumps make team work uneconomical. It seldom pays where the depth of cut or height of fill exceeds 4 or 5 ft. During the summer months the custom among some station men is to do their work partly at night, laying off through the heated part of the day. Station men are not available in great numbers in seasons of extreme heat or cold, preferring to follow 174 HANDBOOK OF EARTH EXCAVATION the mean temperature either north or south. They migrate in pairs and often work in partnership, but it is customary to furnish separate estimates of equal value to the two partners. The contract and estimate system in this work does away with a general pay day, which keeps the majority of the men work- ing all the time and eliminates the timekeeper and disagree- ments in regard to time. The station man expects payment of his estimate immediately upon completion and acceptance, which is arranged by a draft on the nearest bank, unless it is too far away. If no bank is available, the paymaster takes up all esti- mates due every fifteen days, or any authorized party can take them up at any time on the work. In considering the cost of this work it must be remembered that there are general expenses to the owner which would not enter into a larger contract of the ordinary kind. Camps must be maintained and there must be some one to supervise and esti- mate the work of the station men. The cost will be less where many men are employed. The work upon which the following costs are based was done in Southeast Texas during the months shown, and embraced nearly every kind of material, the majority of it being in low swampy country, subject to overflows in one season and getting very dry and hard in others. A large part of it was sticky clay where the borrow pits were filled with grubs, stumps and roots, requiring the constant use of a mattock. Even in places where the stumps are thick, if the earth shovels well without the use of a mattock or any breaking, station work can be done cheaper than the ordinary team work under good conditions. Team, work similar and adjacent to the station work shown in the tables was done at an average cost of 27}X> ct. per cu. yd. WORK BY STATION MEN, Sections 1 to 8 Total cu. yd. moved 4,800.2 Average rate per yd 14.1 Average yd. moved per man day 10.7 Maximum yd. moved per man day 20.0 Minimum yd. moved per man day 5.2 Nearly all the station men made daily wages amounting to more than $1.50, while one-third of them made more than $2.00, one man going up to $2.82. This man handled 20 cu. yd. per day, loading and transporting it in a wheelbarrow. The bank was a low one, as the cubic yards in a 100-ft. section were only 91. The costs for station men in Camp No. 12 were as follows: HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 175 1906. June, July, August, September, October, November, December, Janu- ary to February 22, 1907. To amounts paid station men 48397.2 cu. yd $7,560.36 To amounts paid labor for grubbing, driving team, etc., moving and about camp $ 686.00 Team time 166.80 Foreman in charge of work and camp 620.00 Superintendent 62.66 $ 1,535.46 $ 9,095.82 ll-J . ' "U, bawl jjjjTKf ===== To amounts paid cook : $ 516.60 Flunkey 108.15 Groceries 2,046.44 $ 2.671.19 Credit: By board collected from station men $1,240.05 Board collected from labor, foreman, cook, etc 763.90 $ 2,003.95 $" 667.24 To interest on investment of tools, etc ..$ 347.90 $10,110.96 Cost per cu. yd. for grubbing and labor around camp $0.0142 Cost per cu. yd. for foreman and superintendent 0.0141 Cost per cu. yd. for hauling, etc., and excess of cost of mess Over board collected 0.0173 Cost per yd. of interest on investment in tools, etc 0.0072 Average price paid per cu. yd. as per crontacts 0.1562 Total per cu. yd $0.209 It is of interest to note that a gang of laborers, being paid by the day, working under a foreman, moved 1,549 cu. yd. at a cost of $387.34, making a cost per cu. yd. of 25 ct. This was 4 ct. more than the cost of the work when let by contract to the men. Carts. The method of hauling with one-horse two-wheeled dump-carts is especially adapted to work in narrow cuts, base- ment excavations, and wherever the haul is short ; but in such places wheel scrapers are ordinarily better, unless the haul is over street pavements. The great advantage that carts possess over wagons is ease of dumping (one man can dump them) and especially of dumping into hoppers, scows, .etc. The data of Morris, who kept account of the cost of moving 150,000 cu. yd. of earth with carts, are the most reliable in print. In his work one driver was required for each cart. Trautwine erroneously assumes that one driver can attend to four carts. For the short hauls upon which carts are ordinarily used one driver can attend to not more than two 170 HANDBOOK OF EARTH EXCAVATION single horse carts. Morris found the average speed to be 200 ft. a minute, and the average load i cu. yd. (bank measure, equivalent to 0.37 cu. yd. place measure) on a level haul; ^ cu. yd. on steep ascents, and there were 4 min. of " lost time " load- ing and dumping each trip. As above stated, the cost of picking and shoveling average earth is one hour's wages per cu. yd., while if earth is loosened by plow the cost of loosening is about ^ -hr. wages of team and driver, and the cost of loading plowed earth is %-hr. wages of laborer per cu. yd. Upon these assumptions, and accrediting a driver to each cart with an average load of i cu. yd., we have: Rule. To find the cost per cu. yd. of plowing, shoveling, and hauling " average earth " with carts, add together these items : 1/20-hr's. wages of team and driver and helper on plow; 2/3-hr's. wages of laborer shoveling; 1/4-hr's. wages of cart horse and driver for " lost time." To which addi hr.'s wages of cart, horse and driver for each 100 ft. of haul. \Yith wages of a man at 30 ct. and of a horse at 15 ct. per hr., this rule becomes: To a fixed cost of 35 ct. add 2.25 ct. per cu. yd. per 100 ft. of haul. Fig. 6. Two-Wheeled Cart Made by John Deere Plow Co. If one driver attends to two carts, as is very often the case, the hauling item is y hr.'s wages of a man an.i two horses, or 1.5 ct. per cu. yd. per 100-ft. haul at wages above given. In cities where streets are level, and hard, even if not paved, one-horse carts holding % cu. yd. are used; furthermore horses travel faster than the 200 ft. per minute given by Morris on railroad work, 220 to 250 ft. a minute being the speed at a walk over hard level roads. With large %-yd. one-horse carts and one driver to each cart, the cost of hauling per cu. yd. per 100 ft. HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 177 is therefore, }4 5 lir.'s wages of horse and driver, or 1 ct. per cu. yd. per 100 ft. of haul. Cost with Carts. Engineering and Contracting, Jan. 22, 1908, gives the following: The job was earth excavation in the construction of a rail- road. A cut was taken out with carts, which were loaded by men using short handled shovels. The work was done in the late fall and early winter, when a fair amount of rain fell, but snow falls did not occur. At night the ground froze to a depth of a few inches, and was generally thawed out by the sun during the day. This made, the runway muddy and made some of the shoveling harder. The material was red clay that readily absorbed water. The average length of the haul was 900 ft. The earth was loosened by picks, two pickers keeping three shovels going. Three men shoveled into a cart, two carts being loaded at one time. Four carts were used, one driver attending to two carts, which he took to the dump together. One man on the dump, with the aid of the driver, dumped the carts. The wages paid for a 10-hr, day were as follows: Foreman $3.50 Laborers 1.50 Water boy 1.00 2 carts and 1 driver 4.50 The cost per cubic yard of doing the work was : Foreman $0.050 Picking 0.080 Shoveling 0.130 Dumping 0.021 Water boy , 0.014 Hauling ' 0.110 Total $0.405 The output of this gang per day was 70 cu. yd. This is r high cost, as a greater yardage should have been excavate,!. The pickers loosened about 18 cu. yd. per man day, while aboiu 11 cu. yd. per man day were shoveled. The man on the dump took care of 70 cu. yd. per day. A careful analysis of this and a comparison of costs of similar work show that the cost of hauling is a little low, while the other costs are all high. This leads to the conclusion that there were not enough carts for this length of haul. As the foreman was experienced and realized that he was short of carts, he did all he could to keep them going continually and loaded them as heavily as the ground over which he had to haul would permit. The result was that he worked the horses harder than they are ordinarily worked, as will be noticed from the cost 178 HANDBOOK OF EARTH EXCAVATION of hauling, which was 11 ct. for a distance of 900 ft. With the wages given above, the cost of hauling per 100 ft. with carts would be about 1 ct., and adding to this the lost team time the total cost should have been for a 900-ft. haul about 12 or 13 ct., while the cost, as stated, actually was 11 ct. That the fore- man did his work well is evident from the fact that with a lack of carts that was bound to make his men idle at times waiting for the carts to come back from the dump, he got an output of about 11 cu. yd. from his shovelmen per day. If two more carts had been used, the shovelers could no doubt have loaded 14 cu. yd. to the man, and instead of using only three men loading to the carts four men could have been em- ployed. This would have made the output per day 112 cu. yd. instead of 70. Thus a saving on the total cost of nearly 20% could have been effected. With the material that had to be excavated, a man could readily loosen with* a pick, by caving in a bank, from 25 to 30 cu. yd. per day, and a man could load into a cart with a shovel 14 cu. yd. The dumpman could easily have cared for the 112 cu. yd. that were sent to the dump. The costs as given illustrate in a striking manner how one detail of a job that is not properly managed can materially increase the cost of all the other details and that of the whole job and yet that particular cost may be low. Such facts can only be learned by keeping detail cost data and then carefully analysing them. High Cost of Railway Excavation with Dump Carts. En- gineering and Contracting, Feb. 10, 1909, gives the following data: The excavation was made on the grade of a railroad in taking ot:t several small cuts, there being 1,743 cu. yd. in the combined cuts. The material was a sandy clay, and the average haul was 500 ft. The work was done in the fall of the year with good weather conditions, there being but one rainy day during the time. With this class of material, without any stones in it and the depth of cutting and length of haul, the excavation was ideal wheel scraper work, but as the railroad company did not own any scrapers, it was decided to hire carts and do the work with them. The earth was loosened by a plow, but the plowing was not done well enough, so that some of the men had to pick it. Nat- urally using a plow prevented the material being worked to a breast and the carts were hauled over the loosened material. This made the hauling hard for the horses and prevented full loads from being carried, and also compacted the loosened mate- HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 179 rial somewhat. An average of 17 carts were worked with 58 men and 3 foremen. A single foreman in charge of 29 men, with men and carts scattered over a cut, resulted in poor work. The men clustered around a cart and loaded it as they would a wagon, and, using short handled shovels, the amount of work that could be done in a day was reduced over the number of cu. yd. that could be loaded into a cart at the end with the tail gate out. With such a large number of men per foreman it was also possible for the men to loaf. A 10-hr, day was worked and the following wages were paid: Foremen $2.50 Laborers 1.50 Carts and driver 3.00 Plow team 9.00 '",*- 't'*L ' ":' -->''< !!-,;<;/ ",}']', .'M'f 1 ,. 1 The cost of the work was as follows: Foremen $ 52.50 Laborers 610.50 Cart work 357.00 Plowing 36.00 Extra work 11.50 Total $1,067.50 This gives a cost per cu. yd. as follows: Foremen $0.030 Plowing 0.020 Laborers 0.350 Hauling 0.205 Extra work 0.005 Total $0.610 The extra work consisted of digging some ditches after a rain to drain off the water, two foremen and 12 men being engaged on this for half a day. The very high cost and poor work is shown, by the fact that a man only shoveled 4*4 cu. yd. of a material, that could be classed as average earth, in 10 hr. A man should have shoveled, after the material was loosened, 14 cu. yd. in 10 hr. If scrapers had been used the cost per cu. yd. should not have exceeded 25 ct. Types of Wagons. A series of articles appearing in Engineer- ing and Contracting, Feb. 3. to Apr. 14, 1909, describes the various types of wagons and name of manufacturers on the market at that time at considerable length. A brief abstract of these ar- ticles is here given. The first style of wagon used for earth transportation was the kind now found in common use on farms. This wagon consists of the ordinary running gear with front and back wheels con- 180 HANDBOOK OF EARTH EXCAVATION nected by a coupling pole and with wheels having 2-in. tires. The body is a rectangular box made of 1-in. planed boards bound on top with strap iron. The difficulty of dumping this wagon led to cutting holes in the bottom which were covered with boards. These were lifted with a pick, spilling part of the load and leaving holes through which the rest could be easily shov- eled. The idea of dumping through the bottom brought into use the slat bottom wagon. This consisted of the same style running gear. On the bolsters 2- by 4-in. scantlings were placed to make the bottom of the wagon body; 12- to 14-in. boards were used for the sides of the body. Bottom and side boards were worked down at their ends with a draw knife so as to offer a convenient grip. The wagon was dumped by the driver and dumpman lift- ing these boards one by one. Dumping required about 3 min. The running gear of farm wagons being found too light for continuous use with heavy loads of earth, heavier running gear with 3- and 4-in. tread tires was made for use on construction work. For many years this heavy running gear with the slat bottom body was the standard wagon for earth work. Bottom Dump Wagon. The slat bottom wagon has been largely replaced by various patent self-dumping wagons of which the bottom dump forms the largest class. The bottoms of these wagons consist of two hinged doors which are usually held in place by chains and are released to dump the load. They are built of wood and steel, in capacities of from 1 to 5 cu. yd. The front wheels go under the body, making it possible for a team to turn in its own length. Mechanism is provided by means of which the driver can close the hinged bottom while the wagon is in motion. End Dump Wagons can be divided into two divisions, namely those with tail gates and those without tail gates. Those with- out tail gates generally have the bodies built of, steel, and the body is built of such a shape that the load is discharged by gravity when the wagon bed is tilted for dumping. One advan- tage that this style of wagon possesses is that none of the load can spill or leak out unless too much of a load is placed on the wagon. This style of wagon is not often used for earth exca- vation as the wagon is quite heavy, and owing to the shape that is given it, so it will dump, its carrying capacity is reduced. Those with tail gates are used for earth transportation, and several styles of this class of wagon are in common use in New York City. For dumping into hoppers or bins, and through chutes, or onto scows and barges or into railroad cars they are better adapted than bottom dump wagons, as the horses can be HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 181 backed up to the dumping place. For the above listed classes of work and for dumping on piers and wharves this style of wagon is well adapted. In loading wagons by hand the height of the wagon body is of great, consideration. Every inch additional height decreases in the amount of earth that a man can load in a day. The height of the top of the sides of the ordinary dump wagon, Cat Fig. 7. Bottom Dump Wagon Made by the Watson Wagon Co. of 1 cu. yd. or iy 2 cu. yd. capacity, is from 4.5 to 5 ft. A man at this height will shovel with a short handled shovel about 13 cu. yd. in 10 hr. Over this height to increase the height of the sides of the wagon by 6 in. decreases the amo nt shoveled per man day by about 10%. The reason for this is that in order to cast the earth into the wagon the man must first straighten up his back, after he has filled his shovel, and then by another mo- tion he casts his load into the wagon. With long handled shovels, Fig. 8. End Dump Wagon. in average earth or good clay, men have been known to load into wagons between 14 and 15 cu. yd. in 10 hr., and to increase the height of the wagon 6 in. decreased the amount loaded per man day by about 7%, until the height reached 8 ft. Special Dump Wagons. One of these, the invention of George 'Penine and D. L. Hough, was used in the building of the Penn- sylvania R. R. tunnels under New York City. A lar<.00 Four-horse plow team 9.00 The work was continued for 17 days, the gang excavating in that time 1,293 cu. yd. The daily cost records from the star showed a high cost, and although every effort was made to reduce these costs, and they were reduced somewhat from day to day, yet at the end of the 17 days they were still so excessive that it was decided to with- draw the gang and wait until the grader could be put back into the barrow pit. The cost of doing the work was as follows: Foreman, 17 days $ 51 00 Laborers, 201 days 301.50 Wagons, 125 days 625.00 Plow, 7 days 63.00 Dump men, 36 days 54.00 Total $1,094.50 This gave an average cost per cu. yd. of the following: Foreman $0.040 Loading 0.233 Hauling 0.483 Loosening 0048 Spreading on dump 0.042 Total $0.846 It is evident that this is a high cost. An analysis shows that each man shoveled 6.4 cu. yd. Working against a breast and casting into dump carts, a man should have loaded from 12 to 13 cu. yd. of this material in 10 hr. JEach man on the dump spread 36 cu. yd. of earth in 10 hr. Each team traveled on an average of 10 miles per day and hauled about 11 cu. yd. About 1 cu. yd. was hauled to the load, place measurement, although the wagons were of 1^ cu. yd. capacity. These figures show that the great trouble was in the gait set, both by a few men in loading and by the teams in making a fairly long haul. The loading was slow, so the teams, not being pushed, traveled at a slow pace. As soon as the grader was put to work, the wagons were loaded quickly; they went off to the dump at a faster pace, and a toot from the traction engine pulling the grader caused them to come back from the pit at a trot. A large number of wagons were used with the grader, and there was bound to be much greater interest and enthusiasm in the work and the rate at which it was done, HAULING IN BARROWS, CARTS, Vv'AGONS, TRUCKS 207 This is evidenced by the cost of excavating a yard of the material with the grader, which was as follows: Foreman $0.01 Loading 0.04 Hauling 0.25 Spreading on dump 0.02 Total $0.32 This shows a saving of over 52 ct. per cu. yd., and yet the grader excavated only 300 cu. yd. per day, as it frequently had to wait on the wagons to return from the dump. Cost of Earth Excavation with Wagons During Winter Weather is given in Engineeering and Contracting, Feb. 5, 1908, as follows: The work was done in constructing a railroad in the month of February, when frequent snows and rain occurred, and for a number of days, the ground was freezing throughout the day. The work was started near a large body of water and a cold wind blew from over this water chilling the men and animals. The ground was a sandy loam; and little or no loosening of the material would have been necessary if the weather had not been so cold. The material was taken from a large borrow pit and a few days' work with a plow would have loosened the 1.293 cu. yd. excavated; but, owing to the ground freezing, the plow had to be used 7 days. This alone added 4 or 5 ct. per cu. yd. to the cost. The earth was hauled in wagons an average distance of 2,500 ft. The dump was over a marsh, and an extra man was needed on the embankment to help cast the earth ahead, so the horses could walk over the marsh. The dumpmen also had to knock some of the earth out of the wagons on account of its being frozen. For tAvo days a third man was needed to assist in this work. This added to the cost of dumping. The wagons used were 1^ cu. yd. dump wagons, and they carried about 1 cu. yd. place measurement. Ten round trips were made a day so each wagon took 10 yd. to the dump, and the lost time and time consumed in making the trip averaged one hour for each load. This show's how the cost of hauling was increased as the teams . should have traveled from 17 to 20 miles per day, instead of 10 miles. The men shoveled 6.4 cu. yd. per day. With this kind of material from 12 to 14 cu. yd. per man-day should have been loaded, showing conclusively how the weather affected the physi- cal exertions of the men. This small output of the men increased the supervision cost per cu. yd. 208 HANDBOOK OF EAETH EXCAVATION The wages paid on the job for a 10 hr. flay were as follows: Foreman ................................................ v . $ .50 Laborers ............ ...................................... 1 50 Teams, driver and 2 horses .............................. 4.50 Plow, 2 men and 4 horses ........................... . ---- 9.00 The total cost of excavating and transporting the 1,293 cu. yd. 2,500 ft. was: Foreman .............................................. $ 41.00 Laborers .............................................. 301.50 Teams ................................................. 562.50 Plowing ............................................... 63.00 Dumpmen ............................................. 54.00 Total ................... . .......................... $1,023.50 This gives a cost per cu. yd. for the various items as follows : Foreman ................................................. $0.032 Loosening ............................................... 0.050 Loading ................................................. 0.233 Dumping ................................................ 0.0 '1 Hauling ................................................. 0.435 Total ..................... i ........................... $0.791 To illustrate how the weather affected the cost of this work, a comparison of this unit cost with some work done on the same job during the previous autumn will be made. The weather con- ditions were ideal. The same wages were paid. The cost per cu. yd. for the 2,500 ft. haul was: Foreman ....... . .......................................... $0.016 Loosening ................................................ 0.000 Loading .................................................. 0.125 Dumping ................................................. 0.019 Hauling .................................................. 0.260 Total ................................................. $0.420 No plowing was done as the sandy loam was readily shoveled by the men without any loosening. The men shoveled 12 cu. yd. per day, and the teams carried 1 cu. yd. (place measurement), for a load. They traveled 17 miles per day. Two men were used on the dump, as during February. . Economical Handling of Teams with a Jerk Line. In En- gineering and Contracting, Apr. 14, 1909, W. A. Gillette describes the method of handling teams with a jerk line, as practised in the extreme West. When three or four teams are used, as on road-grader, plow or wagon, this practice should be followed in order to do away with the unnecessary cost of extra drivers. One driver is used for one, two, three, four, five or more teams, and the driver will handle three, four or more teams with one HAULING IN BARROWS CARTS, WAGONS, TRUCKS 209 rein or jerk >line, with as much ease as the ordinary driver handles one team. It is a comparatively simple matter to train teams to respond to a jerk line and to the shouts of " gee " and " haw." It is customary to use a strong braided clothes line for a "jerk line." This line reaches from the "nigh" wheel animal to the " nigh " lead animal, and is fastened to the left hand side of the bit; from this main line a short piece of the line passes under the jaw to the right side of the bit, making a " Y." Fas- tened to the hames on the right side of the "nigh" lead is a "jockey stick" (a short piece of wood or iron) which reaches to a curb strap fastened to the bit of the " off " lead animal. A straight pull on the jerk line pulls the " jerk " line or " nigh " animal to the left, or "haw," and the "jockey stick" guides the "off" animal. A succession of jerks on the line causes the " nigh " or left lead animal instinctively to throw its head to the right, to escape from the jerking, and the " jockey stick " guides the " off " animal to the right also, or " gee." A little patience will teach the lead team to " gee " or " haw " if ths guiding words " gee " or " haw " are shouted every time the line is used. By fastening the following teams to the double trees of the team ahead, they will soon learn to follow the team ahead without being tied, and, as a matter of fact, it is not as handy in turning around if each team is fastened, as it does not permit them to cross over and out of the way of the chain while turning. When a team has been properly trained in turning to the right or "gee," for example, the teams following the lead teams will step over on the left of the draft chain and follow it around until the chain is straight for the return trip; then each animal will cross over to his place on the right side of the chain. Handling Excavation from a Large Cellar. According to Engineering News, October 8, 1914, cellar excavation for the William Penn Hotel at Pittsburgh, Pa., amounted to about 55,000 cu. yd. The depth of cut ranged from 40 to 60 ft. The excava- tion was made by a 1-yd. Thew steam shovel loading into 1.5-cu. ; 1. Koppel steel i\\ mp cars hauled by mules on narrow-gage track. These cars dumped into a 5-yd. skip at the bottom of an inclined hoist tower. This skip when at the' top of the hoist tower, tripped its load into motor trucks. Three trucks and three trailers were in use, each of about 5 cu. yd. capacity. The haul to the dumping-board, at the river's edge, was about 1 mile, and some 400 trips were made in 24 hr., about 75% of the total number of trips being handled during the night on account of the clearer streets. 210 HANDBOOK OF EARTH EXCAVATION The dumping-board consisted of a pontoon bridge (with a planked roadway) built up of girders whose outshore end was supported by two scows. Under the bridge was a bin, into which the trucks dumped through a trap. At the end of the bridge a turntable was built up on the scows. The truck after dumping was turned on this and returned to shore running forward. The spoil was taken away on barges carrying 3-yd. boxes, filled from the bin. At the dump the boxes were lifted off by a derrick. Fig. 25. Tipple Used for Removing Excavated Material from Wm. Penn Hotel Foundations. The Economy of Wagon Train Haulage with Motor Trucks. The motor truck cannot always go where a team can go, and it cannot wait like a team without excessive cost for loading and unloading. In order to successfully compete with teams on er~*h hauling, the motor truck must have haulage conditions which make the ratio of running time to standing time large and high average speeds possible. The following, taken from En- gineering and Contracting, Dec. 3, 1913, indicates that the great- est economy of motor truck haulage often lies in using the truck as a locomotive in connection with wagon trains. During the past two years extensive experiments have been HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 211 made by the Troy Wagon Works Co. of Troy, Ohio, to adapt the wagons, now commonly pulled as trailers by traction engines, to Cherry Way 6ran-r St. M /T/i \y ' V/ V \ M/ ' VV< \ /,<) // V/fF | Y .Sfi.c-t-iQn. A - B Fig. 26. Layout of Plant for Excavating for Wm. Penn Hotel. use with motor trucks. In studying the problem of th? ability of motor trucks to pull one or more trailers, the conclusion 212 HANDBOOK OF EARTH EXCAVATION reached was that the average truck loaded to its rated capacity, in addition to carrying its rated load, develops a drawbar pull equal to about one-half of its rated load. A team of horses will develop a maximum sustained drawbar pull equal to about one- fourth of their weight. It was estimated from the tests that the drawbar pull required to move a ton of material varies from 50 Ib. on a brick street to 150 Ib. on a hard surfaced country road, no grades of consequence considered. Further variations are in pro- portion to grades, road conditions, etc. On average roads with average grades the drawbar pull required is about 250 Ib. per ton of live load moved on a properly constructed vehicle. This was another conclusion drawn from the tests. On this basis an Fig. 27. Turntable Used on Wm. Penn Hotel Job. average 3-ton truck will pull 10 tons live load in addition to the rated load on the truck proper, in other words the drawbar pull of the average 3-ton truck equals that of three 3,000-lb. teams. Figure 28 shows "draft per ton curves for various road con- ditions" from actual tests. In order to take care of possible conditions not obtained in the actual tests, the per ton drawbar p; 11 given in the paragraph above is placed considerably in excess of that shown by the tests. Tests were made in which the trailer plant was three times the number being pulled, % of the plant at the loading point, ^ in transit and } being unloaded, in order to keep the motor truck from being delayed. Table I shows the conclusions reached from actual tests in tons delivered, comparing teams with motor alone, with motor hauling one trailer and motor hauling two trailers. In con- HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 213 ^Average Drafts in Pounds per Ton cf ' Total Live and Dead Load Hauled Grades Fig. 28. Draft per Ton Curves for Various Road Conditions. TABLE I DAILY TONNAGE DELIVERED Length of haul % mile 1 mile 2 miles 3 miles 4 miles 5 miles One team one wagon 27 18 12 Motor alone 42 Motor hauling one trailer 160 140 rt Motor hauling two trailers 280 260 160 110 100 70 TABLE II TON-MILE COSTS Distance of loaded haul in miles % 2 4 6 8 10 One team. One wagon. Cost per ton-mile 0.444 0.319 0.256 0.221 0.214 0.209 Motor alone. Cost per ton-mile 0.480 0.319 0.240 0200 0.186 0.179 0.176 Motor hauling One trailer. Cost per ton-mile 0.210 0.154 0.143 0.137 0.135 0.134 0.134 Motor hauling Two trailers. Cost per ton-mile 0.258 0.167 0.118 0.106 0.104 0.103 0.103 214 HANDBOOK OF EARTH EXCAVATION nection with Fig. 29, Table II indicates ton-mile cost for various outfits and shows considerable economy by the use of trailers. The tabulated results of the tests indicate a saving through the use of trailers. m 40 1 c | A One Team handling One Wagon. 'One Team handling Two Wagons alter not '* Three- Ton Truck without Trailers. > Motor and Tr.ee Trailers, One in Transit. One Loading and ( '.--Motor and Six Trailers. Two in Transit, Two Loading and I t c ttj I ?/7ff fn/o//>> Two Unload ir a f j \ ^- l\ 1 \ Cost per Ion-Mile 6 S 5 \ 1 ) , ^> ^ ^ ^ ^ 1 ^ ^ . we ^ ^-^ =s; "^ "~" m rr izr zz iz: in BS= .^ "= -- -- . ^ "*-*. -- * i OMB D i 1 " * r= J 4 6 tS 7 Distance of Loaded Haul in Miles Fig. 29. Curves Showing Ton-Mile Costs for Various Outfits. After making a study of the difficulties encountered in the manufacture and use of trailers for motor trucks the truck shown by Fig. 30 was designed, and is now placed on the market by the company making the investigations. The specifications for Troy trailers are as follows: Length over all 14 ft. 5 in. Width over all 7 ft. % in. Wheel base is 6 ft 9 in. Wheel height 3 ft. Width of track from center to center of tires, 5 ft. 4% in. Dimensions of frame 3 ft. 5% in. by 11 ft. 10 in. Dimensions of tires 4 x % in. Height from ground to top of frame 2 ft. 10V in. (No load.) Road clearance under axles 17 in. Clear space between steering bars 4 ft. 8 in. Length from end to end of drawbar 14 ft. 8 in. HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 215 Springs 4 ft. by 3% in. Diameter of spindle, 2% in. Bower roller bearings. Weight of chassis 3,330 Ib. Capacity 2 to 5 tons factor of safety 25% overload. Some of the distinguishing features of the trailer are shown in Fig. 30. The draw bar is equipped with springs which provide resiliency on grades and prevent shocks to the motor on starting an A stopping the truck. Special heads are used on the draw bars to act as bumpers between trailers when operated in trains. Fig. 30. End View, Showing Construction of Trailer for Motor Trucks. Types of Tractors. The tractors now on the market can be roughly classified into three divisions. The first includes those types developed from the earlier steam farm tractor engines which were an adaption of the locomotive. They are built with steel tires and are driven either by steam or internal combustion engines. The second division includes rubber tired tractors driven by internal combustion engines which are a development of the heavier motor trucks. These machines are commonly used in connection with a trailer which is usually mounted on two steel tired wheels. The third division includes caterpillar tractors, or machines with '' platform wheels." A Traction Engine Whose Four Wheels are Driving Wheels is described in Engineering and Contracting, Aug. 13, 1913. 216 HANDBOOK OF EARTH EXCAVATION On this traetor all four wheels are of the same size and each carries one-fourth of the total weight of the machine. As no weight is carried which is not useful in producing tractive effort it is claimed that this tractor is "very economical in fuel con- sumption, and because of the better distribution of the weight and the driving action of the forward wheels, it has shown ability t,o work in places where it would be impossible to use tractors of the rear wheel type. As both axles turn in going around curves the radius of turning Fig. 31. 35-hp. Steam Tractor Suitable for Hauling Heavy Grading Machinery. can be very small in the 25-hp. machine, the smallest radius to the inside wheel is 8 ft. The drive wheels are also novel in that the face is of open lattice work so that soft mud squeezes through and allows the cleats to reach a solid footing. For work in exceptionally soft mud or sand extension rims are provided. The tractor has three speeds forward and one reverse, the three forward being 1%, 2*4 and 4 miles per hr. while the reverse is 2} miles per hr. The fuel used is either gasoline, kerosene or distillate. A Tractor and Semi-Trailer Contractors' Hauling Outfit is HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 217 described in Engineering and Contracting, Aug. 10, 11)10. The trailer carries the load, about 70% of the weight of which Fig. 32. Tractor with Four Drive Wheels Made by the Heer Engine Co., Portsmouth, O. is on the rear steel-tired wheels and the tractor pulls the load. The trailer shown has a 120-cu. ft. dump body, but any special form of body required by the character of the load can be used. The trailer is quickly coupled and uncoupled and it Fig. 33. Tractor and Semi-Trailer. is common practice to use three trailers with one tractor, one being loaded, one being hauled and one at destination being un- 218 HANDBOOK OF EARTH EXCAVATION loaded. Any other of several similar combinations of trailer and more than one trailer can be effected to suit the conditions. With the combination as shown by the illustration a turn can be made without backing in a 31-ft. circle and by backing the train can be turned in a 20-ft. street. The wheel base of the tractor is only 80 in., and that of the trailer is 11 ft. 3i/ in. In addi- tion to its short wheel base the tractor has the feature of an independent spring supported from plant sub-frame. None of the load comes on the springs of this sub-frame, but on the heavy Fig. 34. Caterpillar Tractor with 30-in. Plates Attached to Platform Wheel. springs of the main frame. There are two separate sets of springs, one set adjusted to the light constant load of the power plant, gasoline tank and driver's seat, and a second set for the tractor frame proper. The tractor hauling unit as illustrated has been tried out for a season on actual contract work and is marketed with full assurance by the builders of its efficiency. The builders are the Watson Wagon Co., Canastota, N. Y. A " Caterpillar Tractor " for Hauling Over Soft Ground. A nine ton traction engine with its weight so carried that the load upon the ground is only 4i Ib. per sq. in., or about 650 Ib. HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 210 per sq. ft. of bearing surface, is shown in Fig. 34. This machine is operated by a 45 hp. gasoline motor and has been in actual use for a number of years, chiefly in the West and South. It is called the " Holt Caterpillar Tractor." The chief feature x>f the tractor is the platform wheel shown by Fig. 35. Two sprocket wheels, supported by the frame, serve to carry an endless track consisting of cast steel rails cut in short lengths and linked together with manganese steel pins. To the bases of these rails steel shoes are fastened which transmit the weight of the machine to the ground. These shoes are made in 16-, 24- and 30-in. widths so that the bearing per unit area may be suited to the condition of the ground. The widest plates (30 in.) give the bearing of 4% Ib. per sq. in., and the 16-in. plates lessen the bearing area so that the weight per sq. in. id Fig. 35. Platform Wheel of Holt Caterpillar Tractor. increased to 8 Ib. For very soft ground the shoes may be pro- vided with projecting cleats which increase their bearing sur- face. The four small wheels shown by Fig. 35 support the weight of the machine upon the rails. These wheels are of semi-steel with a chilled face and run on roller bearings. It will be seen that this platform wheel arrangement is a device for laying its own track in front of the wheels and picking up the track after the wheels pass over it. A general view of the tractor is shown by Fig. 34. The ma- chine is 18 ft. long, over all, and weighs about 9 tons. The 45 hp. motor, when traveling at a speed of 2% miles per hr., is capable of pulling a load equal to that which can be pulled by 30 horses. The machine can turn in a 30-ft. circle. This tractor will haul trains of wagons for construction work, 220 HANDBOOK OF EARTH EXCAVATION road machines and elevating graders, gang plows, etc., over roads on which the ordinary tractor cannot he worked. It is par- ticularly adapted to the hauling *f plows and in this task has shown some remarkable records of earth broken up. Mr. D. H. Nelson of Pendleton, Ore., states that 960 acres were plowed in 32 days to a depth of 8 or 9 in. This was done at a cost of 47 ct. per acre, or more than 20 cu. yd. were loosened for 1 ct. A machine owned by J. J. Hicky of Thornton, Cal., has plowed 3,000 acres in two seasons and the repair costs have amounted to $425. The tractor described is manufactured by the Holt Manufactur- ing Co., and the Holt Caterpillar Co., whose New York offices are at 50 Church St. Caterpillar Wheels. When wagons are hauled over soft ground by a tractor, not only the traction engine, but the wagons them- selves may be fitted with " caterpillar " traction wheels. Such a wagon train is described in Engineering News, May 20, 1915. The traction engine is of the three-wheel type, with a single wide steering-wheel having ribs to give it a hold in soft ground. The wagons are 11.5 by 9 ft. over all, and 5 ft. 814 in- in height to the top of the body. The carrying capacity of each wagon is about 180 cu. ft., or 10 tons. Miscellaneous Costs of Excavation in Construction of a Smelter. E. H. Jones, Bulletin of the American Institute of Min- ing Engineers, July, 1914 gives the average cost of 131,371 cu. yd. of excavation in the construction of a large smelter at Clifton, Ariz, as 79 ct. a cu. yd. Teamsters were paid from $2.25 to $2.70 per 10-hr, day and ordinary laborer received* $2.00 per 10-hr, day. Excavation was divided into nine classes according to haul and tools used. Class 1. Shallow excavation with picks, shovels, wheelbarrow and slips. Hauls were less than 100 ft. A trestle approach was excavated through cemented sand and gravel permeated with calcine. All the work was done by hand using picks and shovels. The excavated material was cast to the side of the holes and in some cases it was handled three times. There were 277 cu. yd. of earth moved at a cost of $1.30 per cu. yd. A track scale foundation was excavated, being a long narrow cut through earth fill and sand and gravel. It was taken out with picks and shovels and transported 200 ft. with slips or drag scrapers. There were 118 cu. yd. of excavation at $0.92 per cu. yd. A trestle foundation for a siding was excavated through tight red soil filled with large stones. The excavation consisted of a HAULING IN BARROWS, CARTS, WAGONS, TRUCKS 221 shallow rectangular cut. It was picked, shoveled, and wheeled in barrows 50 ft. There were 589 cu. yd. of excavation at $0.93 per cu. yd. A building foundation was excavated and the necessary back fill tamped in 5-in. layers in the low part where the basement con- crete floor was to be cast. It was done with picks, shovels, and wheelbarrows in earth, sand and gravel. There were 322 cu. yd. excavated at $0.89 per cu. yd. An air pipe line trench with a large slice through red clay and boulders into sand and gravel tightened with calcine. It was shaken up with powder, plowed, transported to a trap in narrow gage side-dump cars and conveyed 1,000 to 2,000 ft. by a narrow gaged locomotive. There were 331 cu. yd. of excavation at 68 ct. A floor foundation for a warehouse was excavated, which en- tailed cutting down the floor of the warehouse 6 to 8 in. and back filling in places. There were 66 cu. yd. of excavation at $1.96. Class 2. This type covers excavations made with picks, shovels, slips and carts. The haul was over 100 ft. in every case. A track scale foundation was excavated in tight sand and gravel. It was done with pick and shovel handled in the cars and hauled 500 ft. There were 388 cu. yd. excavated at $0.90. A wall foundation was excavated, being a long narrow cut through earth fill and sand and gravel. It was taken out with picks and shovels and transported 200 ft. with slips. There were 60 cu. yd. excavated at $1.29. A boiler foundation was excavated. This work was digging' shallow trenches for small foundations through red clay and small boulders. The ground was picked, shoveled and hauled 600 ft. There were 120 cu. yd. excavated at $1.65. A storage tank foundation was excavated consisting of making a top slice to prepare the site for foundations of two 500,000 gal. oil tanks. It was done with plows, picks, slips and shovels and was hauled 150 ft. There were 544 cu. yd. excavated at $0.56. Class 3. This class covers excavations made with powder, picks, shovels and wheelbarrows. The haul was less than 100 ft. There were 4,211 cu. yd. of excavation of this type moved at $0.84 per cu. yd. Conglomerate rock was graded off in preparing the site for a well. Large blasts of dynamite were used. .There were 2,600 cu. yd. excavated at $0.80. Wagon roads were made for construction purposes. There were 951 cu. yd. of excavation at $0.97. Water supply tank foundations were graded, a 3-ft. slice being removed with powder, picks, shovels and wheelbarrows. There were 116 cu. yd. of earth moved at $1.24. 222 , ,,| > HANDBOOK OF EARTH EXCAVATION Class 4- This class covers excavation made with powder, picks, shovels, fresnos and carts. _ The haul was over 100 ft. There were 15,541 cu. yd. of this type of excavation moved at $1.00 per cu. yd. Bin foundations were excavated through earth, sand and gravel bonded with calcine. The excavations consisted of long, narrow, deep cuts. Powder and plows were used to loosen the ground. Part of the work was done with slips and fresnos; another part by picks, shovels and wagons. The average haul was 600 ft. There were 12,319 cu. yd. excavated at $0.99. Building foundations were excavated to grade with fresnos hauling the earth 450 ft. Deep cuts were then made through red clay and boulders to gravel to provide for steel foundations. There were 1,216 cu. yd. excavated at $1.27. Retaining wall foundations were excavated through 2 ft. of clay followed by sand and gravel and boulders with calcine. The ground was partly blasted, all picked, shoveled into wagons and hauled 600 ft. There were 306 cu. yd. excavated at $0.93. Another retaining wall foundation was a deep cut through sand and gravel made with picks and shovels. The material was hauled 300 ft. There were 404 cu. yd. excavated at $1.00. Class 5. This class includes excavation with plows, slips, fresnos and in some cases, powder. The haul was less than 100 ft. There were 11,210 cu. yd. of excavation of this type moved at $0.93 per cu. yd. Building foundation excavation consisted of a 6-ft. slice to get the proper grade for the site, together with piers and small wall excavation. Earth was plowed and moved 400 ft. in fresnos. There were 1,458 cu. yd. of excavation at $0.82. Another building excavation was a cut 55 by 280 by 10 ft. for the basement, machine foundation and piers of a power house. The material was red clay and boulders on top, with sand and gravel beneath which was saved for concrete material. Powder was used, followed by plowing, picks, shovels, fresnos and carts. The material was hauled 450 ft. There were 7,313 cu. yd. ex- cavated at $1.07. Railroad grade was formed along each side of an oil sump. There were 2,439 cu. yd. excavated at $0.61. Class 6. This class includes excavation with plows, slips, fresnos and in some cases powder. The haul was over 100 ft. There were 13,160 cu. yd. of excavation of this type moved at $0.89 per cu. yd. Chimney foundation excavation consisted of a deep hexagonal cut through clay, calcine and "sand and gravel containing big boulders. The material was loosened with picks, moved in HAULING IN BARROWS, CARTS' WAGONS, TRUCKS 223 fresnos, dumped through a trap into carts and hauled 2,700 ft. There were 597 cu. yd. excavated at $0.61. ^;; / l}Hif>fOV>tt v! : R = .00827 D 3.6111 + 15, when w - 0.6 R = .01241 D 5.4167 + 15, when w = 0.4 R = .01644 D 7.2222 + 15, when w = 0.3 HAULING IN BARPvOWS, CAPxTS, WAGONS, TRUCKS 229 TABLE IV COST OF LOADING AND HAULING WITH 1-HORSE CART IN CENTS PER CU. YD. (Wages of man, 15 ct. ]>er hr. ; horse, 15 ct. per hr.) Length of haul ft. ?5 50 100 150 200 250 500 1,000 1,500 Load, 0.6 cu. yd 18.9 19.0 19.4 19.9 20.3 20.7 22.7 26.9 31.0 Load. 0.4 cu. vd 20.7 21.0 21.7 22.3 22.9 23.5 26.6 32.8 39.0 Load, 0.3 cu. yd 22.6 23.1 23.9 24.7 25.5 26.4 30.5 38.8 41.0 Bibliography. " Handbook of Construction Plant," Richard T. Dana. " Earth and Rock Excavations," Charles Prelim. A Report by the Construction Service Co. on the cost of Haul- ing by Horses and Traction Engines, Troy Wagon Works, Troy, New York. " Haulage by Horses," Thomas H. Brigg, Transac- tions Am. Soc. M. E., Vol. 14 (1893). "Notes on the Cost of Motor Trucking," Bulletin 2, Massachusetts Institute of Tech- nology. Engineering and Contracting, March, 1906, " Itemized Cost Excavation on Seven Jobs," Daniel J. Hauer; Dec. 18, 1907, "Ad- vantage of Oxen over Horses," D. H. Winslow; Feb. to April, 1909, Comments on the use of wagons in transporting earth; June 9, 1909, Moving contractor's plant over ice; Feb. 19, 1913, Observations and experiments on tractive power of horses; April 23, 1913, A study of comparative upkeep cost of horse- drawn vehicles and electric motor trucks; Feb. 17, 1915, Selec- tion of hauling machinery and graphical method of estimating the comparative cost of hauling. Hauling 400 tons of stone per day with auto trucks, Engineer- ing Record, Dec. 5, 1914. " Notes on the Cost of Loading Motor Trucks from Ground Storage Piles," Engineering and Contracting, Feb. 11, 1914. "Cost of Operating Motor Trucks in Road Main- tenance with Methods of Up Keep," Engineering and Contracting, June 17, 1914. " Motor Trucks Cheaper than Teams on Hauling Gravel," F. P. Scott, Engineering News Record, May 16, 1918. s IM >;/ . ar.2 , , CHAPTER VIII METHODS AND COST WITH ELEVATING GRADERS AND WAGON LOADERS An elevating grader consists of a plow casting a furrow upon a transversely traveling belt that elevates the earth, dumping it into wagons traveling alongside the grader. In sand or gravel, where a plow will not turn a good furrow, the elevating grader cannot be used. There must be few boulders or roots to stop the plow of the machine; and there must be considerable room in which to turn the machine, and manoeuver the teams going and coming. The machine is not well adapted to loading wagons on road work, but is especially suitable for reservoir work and the like. The machine is used in prairie soils for digging ditches and carting the material directly into the road, but the material must afterward be leveled with a leveling scraper or road ma- chine; and it would seem better practice to use the road scraper entirely for this class of grading without resort to the elevating grader at all. In moving fairly soft clayey loam of the Chicago Drainage Canal with New Era grader and wagons, haul being 500 ft., the output was: Section I, September, 485 cu. yd. per 10-hr, day; Section K, August, 490; September, 515 cu. yd. per 10-hr, day. The plant consisted of 7 wagons, 28 horses and 17 men and one grader. With wages at 30 ct. per hr. for men and 15 ct. per hr. for a horse, we have a labor cost of $9.30 per hr. With an output of 50 cu. yd. per hr., the labor cost would be 18.6 ct. per cu. yd. An elevating grader costs $1,400, and the seven dump wagons cost $1,800. This $3,200 plant we may assume can be rented some years, and some it cannot, so that its owner may perhaps estimate using it or renting it for 64 working days annually; with annual interest, repairs and depreciation at 20%, we have $640 a year, or $10 as the charge to be made for each working day. The cost of plant, therefore, adds about 2 ct. to each cu. yd. moved. Where the work is of great magnitude, the cost of the plant may be divided by the total number of cu. yd. to be moved with it, which is a common way of estimating work upon the part of contractors. Summing up we may put the cost of moving earth with elevating graders thus, assuming an output of 500 cu. yd moved 500 ft. in 10 hr.: 230 ELEVATING GRADERS AND WAGON LOADERS 231 Ct. per cu. yd. 10 horses and 5 men on grades 6.0 18 horses and 6 men on 6 wagons 9.0 5 men on the dump and grubbing 3.0 Total labor 18.0 Plant rental 2.0 Total Due to the fact that room must be had in which to move the grader and the string of teams on the wagons, we are not safe in figuring on a haul of less than 500 ft. no matter how short the " lead " actually may be. Using three-horse dump wagons holding 1.25 cu. yd. place - measure for hauling, an elevating grader with five teams and five drivers and helpers, and one man on the dump for every 100 cu. yd. delivered, we have : Rule. To find the labor cost per cubic yard of average earth loaded with an elevating grader and hauled with three-horse dump wagons, add together the following items: i/i -hr.'s wages of a 2-horse team with driver on the grader; %-hr.'s wages of a 3-horse team with driver for " lost time " ; i/ 10 -hr.'s wages of man dumping; then add J,0-hr.'s wages of a 3-horse team with driver for each 100 ft. of haul over 500 ft. With wages at 30 ct. for labor, 15 ct. for a horse, this rule becomes: To a fixed cost of 17.5 ct. per cu. yd. for all hauls under 500 ft. (corresponding to a "lead " of 200 ft.) , add 1 ct. for each additional 100-ft. haul. To this add 2 ct. for plant rental. Traction Engine and Grader. The writer kept the following records of cost, using a 25 HP. traction engine for hauling an elevating grader. Soil was easily plowed earth taken from " pits " alongside the railroad fill. The crew was one engineman, two men operating the elevating grader, one team on water tank, nine two- horse dump wagons, four men on dump spreading, one water boy and one foreman. The " lead " was only 100 ft. The grader traveled 600 ft., in 1 which distance it loaded 15 wagons and then turned around, the turn taking 1 to 2 min. Each wagon had about 1 cu. yd. of loose earth, equivalent to about 0.7 cu. yd. in " cut," and 700 wagons were loaded per 10-hr, day. It took about 15 sec. to load a wagon (the grader traveling about 150 ft. per min.), then the grader stopped for 15 sec. until the next wagon came up into place. It required a width of about 50 ft. in which to turn the grader and engine. Six three-horse wagons would have served much better than the nine two-horse wagons used. The traction engine uses about 0.7 ton of coal per day of 10 HANDBOOK OF EARTH EXCAVATION O 2 w ^ If DQ II ELEVATING GRADKRS AND WAGON LOADERS 233 234 HANDBOOK OF EARTH EXCAVATION hr. Annual interest, repairs and depreciation may be estimated at 20% of the first cost. Ordinarily a tractor can not be counted upon to work more than about 100 days each year, year in and year out. Widening Wheels of Grader for Work Over Soft Ground. A method of increasing the bearing areas of elevating graders that should be of interest to dirt movers was employed in the con- struction of the Sieberling Division of the Lincoln Highway across the Great Salt Lake Desert of Utah. Heavy rains made the soil so soft that it was difficult to operate the road ma- chinery. Extra bearings were accordingly piaced on the wheels Fig. 3. Paddles on Wheels of Elevating Grader. of the elevating graders and the caterpillar treads of tractors. On the graders the outer ends of the planks were supported by a ring. Diagonal brace rods extended from the hubs of the wheels to the planks. The arrangement is shown in the accompanying illustration, which is taken from Engineering and Contracting, March 10, 1919. Method of Using Elevating Graders on Earth Roads. In road building, an elevating grader will take the earth from the ditch and deposit it directly into the grade where wanted, in one opera- tion. Fig. 4 taken from the catalog of the Russell Grader Mfg. Co. of Minneapolis, Minn., shows the method of building a road grade. The figures and letters indicate the order in which the furrows are plowed up in the ditch and the respective points of delivery in the grade by use of 16-ft. carrier. For instance, ELEVATING GRADERS AND WAGON LOADERS 235 furrow No. 1 indicates the first one handled and is delivered about four ft. across the center of the road to the point indicated by the Fig. 1. Furrow A is taken on the opposite side of the road and delivered to a similar position about four ft. across the center. (This method is called crossfiring. ) Each respective furrow is taken out of the ditch in the order numbered, the fifth and sixth furrows doubling up in the center and the first plowing in itself leaves a substantial grade with ten furrows or rounds. The second plowing takes out furrows 11 to 17 respectively, Fig. 4. Method of Building a Dirt Road by " Crossfiring" with an Elevating Grader. bringing the grade up to a height of approximately 30 in. With a berm as shown it will permit driving on the side until the grade is ready for travel. As the grade is dressed down and as the roadbed becomes firmer the earth will work out toward the edges onto the berm and eventually becomes a grade with a gradual curve from the ditch to the crest. According to the manufacturers a mile of road such as shown by the diagram can be built by 17 rounds or hauling the machine a distance of 34 miles, or in about 2 days' time. Data on Elevating Grader Work. I have seen 700 two-horse wagons, holding % cu. yd. each, loaded per 10-hr, day; and, I am informed, that with good management and an easy soil, 700 wagons, holding more than 1 cu. yd. each, can be loaded per 10-hr, day. With three-horse wagons the average 10-hr, day's output on the Chicago Drainage Canal was 500 cu. yd. of top soil. Mr. N. Adelbert Brown, C. E., of Rochester, informs me that an elevating grader was used by Thomas Holihan, in grading streets at Canandaigua, N. Y. The streets were 60 to 75 ft. wide between property lines, and 36 ft. between curbs. A traction engine was used to haul the grader, and there was no trouble in turning the engine and grader between the walk lines, which was easily within 50 ft. of space. " The efficiency of the machine was not tested fully, due to a lack of teams; but, when teams were available, 50 wagon loads, of 1^ cu. yd. each, were readily loaded in an hour. The machine was satisfactory in stone and gravel 236 HANDBOOK OF EARTH EXCAVATION roads and stiff clay, but in light sand in some cases refused to elevate." This latter is true, however, of all elevating graders in any dry sand that will not turn a furrow. Fred T. Ley & Co., of Springfield, Mass., inform me that ele- vating graders were used by them on electric railway work in cen- tral New York state, both with traction engines and with horses. They averaged 400 to 500 cu. yd. loaded into wagons per grader per day. No matter how short the lead, a team hauling earth from a grader must perform a large percentage of waste labor following the grader, and this is equivalent to adding about 400 ft. to the " lead." It is necessary to spread the earth on the dump to prevent stalling of the dump wagons, but by using a leveling scraper the cost of this item can be reduced below the cost of hand leveling. In Engineering-Contracting, Apr., 1906, there is an article by Mr. Daniel J. Hauer, giving costs of elevating grader work on 7 railroad jobs. The limitations of the grader for narrow through cuts are well shown. The average cost was as follows for an average " lead " of 800 ft., with an average daily output of 288 cu. yd. per elevating grader: Per cu. yd. Loading $0.100 Hauling 0.127 Dumping and spreading 0.029 Water boy 0.002 Foreman 0.010 Total $0.268 The wages of the grader operators were $1.50 per 10-hr, day; laborers, $1.50; two-horse team and driver, $4.60; three-horse team and driver, $6.25. The $0.268 does not include any allow- ance for interest, repairs and depreciation. This is probably as high a cost for elevating grader work as will be likely to occur with the same length of haul and the same rates of wages. Cost of Elevating Grader Work on the Belle Fourche Dam. In Engineering News, Apr. 2, 1908, Mr. F. W. Hanna gives the cost of work during 1906-07 on the Belle Fourche Dam, South Dakota. The material, consisting of a heavy adobe clay with occasional layers of shale, was excavated and placed by graders and wagons and by steam shovels, cars and locomotives simul- taneously. The cost of the steam shovel work is given in Chap- ter XIII. Two Western elevating graders of standard size were drawn by .16 horses or by two 32 hp. 21-ton traction engines. Material was loaded into 24 3-horse dump wagons, each holding 1.1 cu. ELEVATING GRADERS AND WAGON LOADERS 237 yd. of material as measured in place. The water-measure ca- pacity was 1.5 cu. yd. The average length of haul was approx- imately 1,300 ft. The material after being dumped was spread with a 6-horse road leveler and rolled in 6-in. layers by a 21-ton traction engine and road roller. The cost of common labor was $2.25 to $2.50 and of horses $1.15 per day of 10 hr. Coal cost $10.50 per ton delivered. The cost as given in the accompanying table includes superin- tendence and overhead charges, which amounted to about 2.2 ct. per cu. yd. TABLE COST OF GRADER WORK ON BELLE FOURCHE DAM EM- BANKMENT FOR 1906 AND 1907. (Total yardage for both years, 199,000 cu. yd. Daily 10-hr, average per grader, 566 cu. yd.) Cost per cu. yd. Excavating Labor $0.047 Depreciation and repairs 0.017 Supplies , 0.012 Total excavating $0.076 Hauling Labor $0.126 Total hauling $0.126 n;ju; Spreading Labor $0.016 Depreciation and repairs 0.001 Total spreading $0.017 Rolling Labor $0.008 Depreciation and repairs 0.005 Supplies 0.008 Total rolling $0.021 Watering Labor /. .V : :; : i WJi $0.011 Depreciation and repairs 0.011 Supplies 0.003 Total watering $0.025 Grand totals Labor $0-208 Depreciation and repairs 0.034 Supplies 0-023 Total $0.265 Cost of Stripping a Gravel Pit. George Rathjens in Engi- neering and Contracting, Jan. 19, 1910, gives the following: 238 HANDBOOK OF EARTH EXCAVATION During the month of September, 1909, the following record was made in stripping a gravel pit in the Dakotas. The pit in question was evidently of glacial origin and was covered with a sandy loam, there being a number of pockets of varying depths, the maximum about 10 in. The length on the railroad right of way was 3,000 ft., the width 50 ft. and the length at the back 2,000 ft., one end being square with the railroad. The contract called for stripping a width of 250 ft., the material being car- ried from the track towards the back of the pit and deposited in winrows with a base of 45 ft. A part of the material was used for grading the straight storage tracks paralleling the main line, the pit being on a curve. The outfit consisted of 1 Austin grader, 6 11/4 cu. yd. dump wagons, 4 No. 2 wheelers and 2 plows. Two more wagons could have been used to advantage, as the grader sometimes had to wait for wagons. The grader usually worked a strip or line about 350 ft. long by 35 ft. wide, with an average haul of about 150 ft., the longest haul being 220 ft. Wheelers were used where pockets were found. The contractor owned his teams, but teams with drivers were worth $5 per day when hired. Hay and other feed was pur- chased from nearby farmers. During the month mentioned the contractor stripped 19,970 cu. yd. at the costs here given: Austin Grader: 2% teams on push,* 24 days at $5 $ 300 8 teams on machine, 24 days at $5 960 Dump Wagons : 5V 2 teams, 24 days at $5 660 Wheelers : 3 teams on wheelers, 11 days at $5 165 1 team on plow, 11 days at $5 55 1 team on scraper, 11 days at $5 55 Labor : 1 foreman, straight time .^ \ 85 1 mucker, 24 days at $2 A , y '<'r 1 corral man, 28 days at $2 ffrtyr* ^ 2 Austin grader drivers, 24 days at $2.25 108 Total $2,492 * Teams on push operated the elevator, team power being the only power used. . . .; ^IU^IITI The cost is almost 12i ct. per cu. yd. The total time was 28 days, as shown by corral man's pay, but 2 working days were lost on account of rain and 2 on ac- count of dust. The expense of feeding teams and cost of repairs and interest are not included. ELEVATING GRADERS AND WAGON LOADERS 239 Coal Stripping with an Elevating Grader. Engineering and Contracting, June ID, 1018, describes the methods employed in stripping an 80-acre track of coal land in Kansas. The coal property is a rectangular piece of land, extending throughout its full length along the railroad right of way. The two small preliminary pits taken out with fresnoes comprise the corner nearest the railroad and highway. The remainder of this strip bordering the railroad was to be left to the last, when it would be taken out with an elevating grader. in his plans the contractor divided the remainder of the tract into five box pits about 700 ft. long, as shown in the diagram. The first of these box-pits, to be stripped, is 72 ft. wide at the top and 60 ft. at the bottom. The next pit will bottom 40 ft. 60 x 7oo 75 x 7oo Box PIT 6o7oo Now Fig. 5. Diagram of Stripping Operation. wide; the third, 75 ft.; the fourth, 40 ft., and the last, running to the edge of the property under lease, 60 ft. These five box-pits will not be stripped in continuous suc- cession but alternately, the two inside pits (shaded in the dia- gram) each 40 ft. wide at the bottom and 700 ft. long, being left until the last. When he comes to strip the two inside pits, by using a longer elevator on his machine, the contractor expects to be able to cast fully two-thirds of the material, which will be a very inexpensive operation and will reduce his yardage cost materially. The slopes will be taken out eventually with fresnoes. The average cut in the pit now being stripped is 16^ ft., with a maximum of 21 ft., and the material is a very tough gumbo and hard shale, covering 35 in. of coaf. For stripping the con- tractor is using a Western standard elevating grader, drawn by a Reeves tractor, loading into Western 1^-yd. dump wagons, three horses to a wagon. The cut is being made with one side per- 240 HANDBOOK OF EARTH EXCAVATION pendicular and the other, toward the adjoining box-pit, with a slope of ^ to 1. He finds eight wagons the proper number for economical work and under favorable conditions can move from 750 to 800 cu. yd. of material in a 9-hr. day. Three-horse teams are necessary because as the pit grows deeper the load must be lifted to a considerable height. The wagons work both ways out of the pit, there being a dump at each end. The working force consists of an engineer, steersman for the tractor, machine man, eight drivers, a dump man, a man for the water team and a corral man. The machine man is also a blacksmith. Repairs are nrade on rainy days when possible. The contractor acts as his own foreman. If the machine man is called away for blacksmith work while the machine is operating, the contractor takes his place. When the contractor is called away the machine man acts as foreman. This organization works 9 hr. a day, from 7 to 12 and from 1:30 to 5:30. A Trap for Loading Cars with Dump Wagons is described in Engineering and Contracting, April 16, 1919, as follows: An interesting method of trap loading with Western dump wagons was employed in the construction of an 8-mile railroad for the development of silica beds near Fowler, Kans. The illustra- Fig. 6. Trap for Loading Cars with Dump Wagons. tion, from the Earth Mover, shows the method of loading strip- ping material which was used for ballast. The elevation of the hill where the stripping took place was slightly above the level of the platform. In the platform was a trap door on hinges, so fastened that it could be tripped at will. The wagons from the elevating grader were driven successively to the platform and ELEVATING GRADERS AND WAGON LOADERS 241 dumped upon the trap door without stopping the teams. After each load had l;een discharged the door was tripped, letting the material fall into the car below. Such an arrangement permits a free movement of the team and does not restrict the output of the elevating grader. Elevating Grader on Railroad Work. Mr. J. R. Taft presents some interesting data of the methods and cost of operating an ele- vating grader on railroad construction in Engineering News, Sept. 10, 1914. The use of this machine for taking out railroad outs is unusual, as local conditions generally do not permit the use of such an outfit, except for work spread over comparatively large areas and of shallow depth. Owing to the rolling character of the country, consequent long hauls, and apparent absence of rock or stone, the contractor decided to take out cuts by elevating grader and wagons. The excavation altogether amounted to about 20,000 c . yd. place measure, 94% of this amount being re- moved by machine, the remaining 6% being unfavorable for ma- chine work because it was either root-bound surface soil or high places at the bottom of cuts. The work was done on the Halit and Northern Railroad in Livingston County, N. Y. The machine used was an Austin elevating grader, hauled by a 20-ton steam tractor. The wagons were 1^-yd. bottom-dump wagons, drawn by 3 mules each. The outfit was supplemented with a light grading equipment of Fresno, wheel and drag scrapers used in places inaccessible to the grading machine. The material was a stiff clay, hard when dry and plastery and sticky when wet. Wet weather prevented work in such material and the grading machine co,.ld not be used during the greater part of November, December and January. A cut 20 ft. wide was too narrow for the machine to work in, and it was necessary to over-cut the prescribed section to a total width of 30 ft. Even a 30-ft. cut did not provide sufficient room for loading all the material into wagons working in the cut when working along the center line. Therefore when taking out the middle third of the width, considerable re-handling was necessary, the material being cast up on the sides by the machine, and later rakeJ down by slopers, to a position from which it could be again picked up and loaded into wagons. When the machine was working alone, the teams were used on light grading elsewhere. A wagon load of a little less than 1 cu. yd. place measure was removed for each 6 ft. the machine travelled. Stones embedded in the tough material were caught by the plow point and caused severe strains to the whole apparatus, which were relieved by the shearing of the bolts in the plow frames. Many hundreds of bolts were broken and replaced causing many unrecorded delays of from 242 HANDBOOK OP EARTH EXCAVATION 5 to 15 min. each. The total time of 119 days during which the maching was working in the cut (not including the removal of about 4,000 cu. yd. from the marl pit) was classified as follows: Days % Unnecessary delays. Lack of duplicate parts 6 5 Delays by work elsewhere on the line 5 4 11 9 Necessary delays. General repairs 6 5 Wet ground 43 36 Total 49 41 Total delays 60 50 Machine and operation 59 50 Total working time 119 100 Considering the work as a whole, it was not executed under favorable conditions. Eliminating the item of wet ground from the total working time of 119 days, 76 days were consumed in excavating about 20,000 yd., giving a daily average of about 260 cu. yd. In areas that were not so constricted about twice this output might be expected. The daily cost of operations was as follows: (A) At Working Point Foreman ( member of firm ) $ 6.00 Tractor engineman 4.00 Tractor steersman 2.00 Machine operator 3.00 Tank-wagon driver 2.00 Kxtra tank wagon with driver 5.50 Total $22.50 Fuel, oils, etc., for tractor 5.00 Six dump-wagon drivers, at $2 12.00 Two dumpmen, at- $2.25 4.50 $21.50 Total at working point $44.00 (B) At Camp One blacksmith $ 3.00 One barnman at $40 per month and board 2.00 One cook at $40 per month and board 2.00 Total $ 7.00 Corral expenses for 25 head of mule stock 20.00 ' Total at camp $27.00 Total of (A) and (B) $71.00 For insurance, interest, depreciation, etc., 12^% 9.00 Grand total $80.00 Assuming $80 as a fair figure for daily expenses, the cost of moving 260 cu. yd. per day was about 31 ct. per cu. yd. Board ELEVATING GRADERS AND WAGON LOADERS 243 with lodging in camp was furnished the men at $4.50 per week, which was practically at cost. Corral expense was based on oats at 64 ct. per bushel, loose hay at $21 per ton, and straw at $10 per ton; all haulage by the contractor. Tractors for Pulling Graders. Prof. A. B. McDaniel in Engi- neering Record, July 31, 1915, gives the comparative cost of using animals and gasoline tractors, for pulling elevating graders. His estimate is based on average working conditions on road construction in comparatively level country, where the earth is to be removed from the side of the road to the center. The de- tailed estimate and cost is given as follows: COMPARATIVE COSTS OF EXCAVATION WITH ANIMAL POWER AND GASOLINE TRACTOR Animal Power 7 teams, at $2.50 $17.50 2 drivers, at $2.50 5.00 1 operator 3.00 Total labor cost $25.50 General : Interest on investment at 6% $ 1.20 Depreciation, based on 10- yr, life 2.00 Repairs and general expenses 1.30 Total general expenses $ 4.50 Total cost for 10-hr, day $30.00 Excavated per day 800 cu yd. Cost per cu. yd 3.75 ct. Gasoline Tractor Labor : 1 engineer $ 5.00 1 operator 3.00 Total labor cost $ 8.00 Power : Gasoline, 30 gal., at 15 ct $ 4.50 Cylinder oil, 1% gal., at 36 ct 0.54 Grease, 2 Ib 0.20 Repairs, waste, etc 0.76 Total power cost $ 6.00 General: Interest on investment at 6% : $ 2.40 Depreciation, based on 10-yr. life 4.00 Repairs and general expenses 1.60 Total general expenses $ 8.00 Total cost for 10-hr, day $22.00 Excavated per day 1,000 cu. yd. Cost per cu. yd 2.2 ct. When it is necessary to carry the earth along the road, as in the making of cuts and fills, dump wagons must be used. For 244 HANDBOOKS OF EARTH EXCAVATION a haul of 300 ft., one elevating grader can handle five wagons, and one additional wagon is needed for each 100 ft. in additional length of haul. If the cost of a wagon and driver is $5 per 10-hr, day, and of a foreman, $3 per day, the cost will be increased from about 8 to 12 ct. per cu. yd. A New Excavating Machine. Engineering and Contracting, Jan. 6, 1916, describes the excavator shown in Fig. 7, the essential features of which are gang plows and a scoop. The machine plows seven furrows, 6 to 12 in. deep, and the scoop handles 56 cu. ft. at each trip. The machine is designed for loading earth Fig. 7. New Type of Elevating Grader. Made by L. C. Wood & Co., Alden, la. into dump wagons in railway grading, reservoir dam construc- tion, and in ditching for irrigation and road work. It is operated by a 35-hp. double cylinder traction engine, con- structed with a winding drum and anchors so that the engine remains stationary while the excavator is in operation. The ma- chine is drawn ahead about 7 ft. for a load then, without stop- ping the engine, the scraper is unlocked, fills and is drawn up the track and dumped onto the conveyor. The conveyor discharges into dump wagons at either side of the machine. The machine is 8 ft. wide and 38 ft. long. It weighs about 12 tons. About 150 ft. of 1%-in. steel cable is used so there can be several loads handled without moving the engine. The machine ELEVATING GRADERS AND WAGON LOADERS 245 is drawn from place to place behind the traction engine. It is ready to work as soon as the motor on the machine is started, and begins loading as soon as the engine is unhooked, the cables hooked together and the engine run out to the end of the cable. The small motor on the machine furnishes power to operate the conveyor, to control the plows, to steer the machine and to raise and lower the front end of the machine. When the machine is working the front wheels are on top of the ground and the rear ones travel behind the scraper where the plowing has been picked up. The machine, therefore, always works on the level. In operation one man is required on the machine and two on the engine. The engine is of special design for operating the ma- chine. Both are built almost entirely of steel and steel castings. The machine is constructed to handle very hard material, such that if plowed with teams, three or four teams would be required on a single plow. A full load is handled in 20 sec. and, in service, from 80 to 100 loads are handled per hour. A Wagon Loading Trailer. The Insley Mfg. Co. make the ma- chine shown in Fig. 8. This machine is hooked to the back of a wagon after the roadway has been torn up by the rooter plow, and the four-horse plow team is used as a snatch team in grading Fig. 8. Wagon Loading Trailer. and loading. This machine will load 6 wagons of li/ cu. yd. capacity in 20 min. and should average 24 cu. yd. per hr., taking the place of 12 shovelers and loading a wagon in one-half the time. Bucket-Elevator Wagon Loader. A machine of this type is made by the George Haiss Mfg. Co. of New York. This is a bucket conveyor mounted on a steel frame wagon body and op- 246 HANDBOOK OF EARTH EXCAVATION erated by a 7%-hp. motor or gasoline engine. The machine weighs 3000 Ib. and is designed for use on storage piles and in sand and gravel pits. Cost data on its use in handling gravel from a storage pile are given in Engineering and Contracting, May 16, 1917. Comparative test of this work by hand labor and by the use of the loading device showed the following results: Hand labor. Loading wagons, 8 laborers, 3 yd., 13.00 min. @ $0.25 $ 435 Loading auto truck, 8 laborers, 2% yd., 10.00 min. @ $0.25 415 Cost of auto truck @ $1.00 per hour 160 C&st per 5V 2 yd $1.010 Cost per yd 184 Wagon loader. Loading wagons, 2 laborers, 3 yd., 4.8 min. @ $0.5 $ .040 Loading auto truck, 2 laborers, 2% yd., 4.0 min. @ $0.25 033 Cost of auto truck @ $1.00 per hr 066 Power @ V 2 ct. per cu. yd 028 Oil, grease, interest on investment 010 Cost per 5% yd $0.177 Cost per yd ^ $ .032 Cost per yd. hand labor 184 Cost per yd. machine 032 Amount saved per yd $0.152 The above saving is entirely exclusive of supervision and over- head charges. Fig. 0. Haiss Bucket Elevator for Loading Wagons. ELEVATING GRADERS AND WAGON LOADERS 247 The digging or feeding device used with the Haiss loader is shown in Fig. 10. Loading Machine for Surface or Underground Work. A load- ing machine, specially designed for underground work, has been placed on the market by the Wellman-Seaver-Morgan Co., Cleve- land, O. This machine digs loose ore, dirt or muck by a con- tinuous scooping process the material being taken up by scoops or buckets on an endless chain elevated and dropped into a hop- per which feeds to a conveyor belt which in turn loads into a car. The scooping mechanism is so pivoted that it can dig to the Fig. 10. Propeller Feeding Device on Bucket Elevator Loader. side as well as in front of the machine. The ore, however, being delivered to the conveyor through the hopper, reaches the car behind the loader no matter at what angle the scoop is working. The movement of the scoops is continuous not reciprocating. The machine is self-propelled and is so dimensioned that it can easily be transferred around the mine. It is claimed that it will load at the rate of over a ton a minute and may be operated by unskilled labor. While designed particularly for underground work, the loader can also be used on the surface for loading coal from piles to cars, removing piles of rock and sand and similar operations. The loader is fitted with motors wound for 230 volts, 248 HANDBOOK OF EARTH EXCAVATION Fig. 11. McDermott Continuous Loading Machine. Fig. 12. Scoop Conveyor. ELEVATING GRADERS AND WAGON LOADERS 249 D. C., providing power for all of the operations. The general di- mensions of the loader are as follows: Maximum overall length, 15 ft. 9 in.; maximum height, 5 ft. 6% in. with buckets in lowest position; maximum overall height, 6 ft. life in., when machine is in operation ; maximum overall width, 4 ft. ; gauge of truck wheels, 24 in. Maximum rated ca- pacity with full buckets is 1.75 tons per min. and the average rated capacity is 45 tons per hr. The weight of the complete machine is 8,000 Ib. A Scoop Conveyor for Loading and Piling, made by the Port- able Machinery Co. of Passaic, X. J., is illustrated in Fig. 12. The capacity is said to be one ton per minute. Fig. 13. L 7 ndercutting Method of Feeding Conveyor. An Undercutting Bucket Conveyor Loader, made by the Barber Green Co. of 525 West Park Ave., Aurora, 111., is shown in Fig. 13. Bibliography. " Handbook of Construction Plant," Richard T. Dana. " Excavating Machinery," A. B. McDaniel. " Elevating Graders on Massena Canal, N. Y.," Eng. News, Dec. 15, 1898. "Steam Excavating and Grading Machine," En;/. News, Aug. 15, 1901. "Engineering Work on Louisiana Purchase Exposition," Eng. News, April 23, 1903. CHAPTER IX METHODS AND COST WITH SCRAPERS AND GRADERS Probably some form of log drag has been used for leveling ground since men have known how to plow. A board with han- dles served the purpose of the log drag and was more easily dumped. From this was evolved the buck scraper to which were fitted wood sides and back to increase its capacity until it became a scoop. This in turn was followed by the steel scoop in various forms. For long hauls the scoop was fitted with wheels. Cables and hoisting engines were used first to assist the horses in filling scrapers and after that for moving them as well. This permitted the use of larger and heavier buckets. Thus the evo- lution of the present dragline excavator can be traced, step by step, from the early horse drawn leveling devices. From the log drag also evolved the leveling scraper or earth hone. The largest size consists of a long blade carried in a frame on four wheels, and is called a road grader or road ma- chine. An elevating grader, or grader, is an entirely different type of machine. It has a plow that delivers the earth onto an inclined oadless belt, as shown in Chapter VIII. Buck Scrapers. The buck scraper was originally an upright Fig. 1. Buck Scraper. Width 48 In., Weight 75 Lb. 250 SCRAPERS AND GRADERS 251 board about 8 ft. long and 2 ft. high, shod at its lower edge with iron, provided with a tongue for the team in front, and a platform at the rear upon which the driver could stand. During loading the driver would stand on this platform, and if the soil was at all tough, one or two more men would add their weight. Upon reaching the proper place on the embankment the driver would step off the platform and the scraper would flop over or dump automatically. A buck scraper of this size requires four horses to pull it. The material is not carried by any scoop or bowl as with the drag scraper, but is pushed or " drifted " along in front of the blade. The modern road machine, in which the blade is supported by a framework carried by four wagon wheels, is a development of the buck scraper. So also is the smaller leveling scraper. Fig. 2. Tongue Scraper. (Weight 120 Ib.) Scrapers in Ditch Excavation. From Engineering and Con- tracting, June 23, 1909. The simplest tool, beside the pick and shovel, with which a trench or ditch can be excavated, is a scraper. In narrow trenches and ditches a drag scraper is used. Shallow trenches can be excavated entirely, excepting the trimming up, with a drag scraper. But for deep trenches, either a long ^run has to be made to overcome the grade, or a very steep grade has to be as- cended with the loads. This naturally makes an economic limit for this work. The writer has used drag scrapers for trenching and has found in the country that deep trenches could be exca- vated cheaply by first excavating from 4 to 6 ft. with drags, making a slope on the sides of the trench. This slightly in- 252 HANDBOOK OF EARTH EXCAVATION creases the yardage, but the scraper work, with a short run, is done at a low cost, and by sloping the top of the banks, much money is saved in the sheathing which is an important item, especially when timber is used. Fig. 2 shows a drag scraper called a tongue scraper. This scraper is made of wood bound with metal and derives its name from the fact that a tongue is used in it, while with other drag scrapers a tongue is not needed. The tongue scraper is operated in a manner similar to a drag and although it can be used in a trench to advantage, especially at the top, yet it does its best work in shallow ditches, and is an excellent tool for cleaning out trenches. Fig. 3 shows a Haslup side scraper, manufactured by the Sidney Steel Scraper Co., of Sidney, Ohio. It is meant entirely Fig. 3. Haslup Side Scraper. for ditch work, although it can be used in shallow trenches. It gets its name from the fact that its shape allows it to go out the side of a ditch, instead of moving along in the ditch and go out at a runway as a drag scraper has to be worked. The side scraper does rapid work in making shallow, narrow ditches and also in cleaning out ditches. It can also be used in wider ditches. It is made of metal like a drag scraper, and the shape of its handle facilitates its work. Unless the material is very soft or sandy, in using all of these scrapers it is necessary first to loosen the earth in the trench or ditch by plowing or some other mearns. Cost Data on Use of Buck Scrapers. Geo. J. Specht, to whose paper on earthwork reference was previously made, used buck SCRAPERS AND GRADERS 253 scrapers in moving very large quantities of earth in building levels and in digging small canals in California in 1882 to 1884. His records of cost are the most complete to be found in print. Horses were hired by the contractors at 37.5 ct. to 50 ct. per day per head, and feed cost 35 to 40 ct. Chinamen were employed as common laborers at $1.15 per day, and white la- borers as drivers, etc., received the same plus their board, which cost 40 ct. a day for food alone. Although most of the soil was sandy loam, four to eight horses were hitched to a plow with one driver and one man holding plow. On the Upper San Joaquin Irrigating Canal, which was cut into a steep side hill, the buck scrapers with four horses attached traveled 400 ft. in making a round trip, and went loaded down a slope of about 1 in 4, returning uphill empty an unusually favorable condition. Mr. Specht says that 95 round trips were made in 9 hr. by each buck scraper, and as the result of a great many observations he found the average load to be 1.3 cu. yd., although as high as 1.64 cu. yd. in one case. He gives 128 cu. yd. as the average daily output of each buck scraper. It should be observed, however, that the material was all pushed down a very steep hill. From the foregoing it appears that it took 5.7 min. to make a round trip of 400 ft., which is equivalent to a speed of 70 ft. a minute, including stops. This is so extra- ordinarily slow that we are very much inclined to believe that the actual speed was greater, but that each load was very much smaller than given by Mr. Specht. Mr. Specht gives the follow- ing data of cost for Nov., 1882; 27% days worked: 6-horse plow (with 2 men) 29% days at $9.00 $ 4-horse plow (with 2 men) 15% days at 7.00 108.50 4-horse buck scraper (with 1 man)... 409 days at $5.50 2,249.50 2-horse drag scraper (with 1 man)... 130% days at $3.50 456.75 White man on dump 33 days at 1.50 49.50 Chinese laborers 328 days at 1.50 492.00 Chinese bosses 18 days at 2.00 36.00 $3,657.75 General expenses (foreman, bookkeeper, blacksmith and hostler).. 300.00 55,925 cu. yd. excavated at 7 ct $3,957.75 it'> K[ <>.} 9tJi > .'iiqjr' h'>JHl"l mfi . ]>9mif yd. were moved at a cost of 14 ct. per cu. yd., 4.6 ct. being for labor and 9.4 ct. for teams and drivers. To this were added 0.5 ct. for tools, 0.5 ct. for sundry expenses, and 3 ct. per cu. yd. for foremen, making a grand total of 18 ct. per cu. yd. The foreman item would not ordinarily exceed 1 ct. per cu. yd., but in this case frequent rainy spells flooded the creek bed and stopped work, during which time the foreman's pay went on. Not including plow teams, the output per drag scraper team was 37 cu. yd. per day. The very same gang later, under another and better foreman, moved 15,000 cu. yd. of clay, at the rate of 48 cu. yd. per scraper per day, and including plow teams, of which there was one to every six scrapers, the output was 38 cu. yd. per team-day of 10 hr. There were 8 men, beside drivers, for every 10 teams, so that the cost was 9.25 ct. per cu. yd. for team work, 3.15 ct. for labor, 1 ct. for foreman, and 0.5 ct. for tools and sundries, 258 HANDBOOK OF EARTH EXCAVATION making a total of nearly 14 ct. per cu. yd. We believe that it would be difficult to better this output in stiff clay, for the horses and men all worked with energy. In excavating 2,100 cu. yd. of gravel in a road cut to a depth of about 32 in., the top 8 in. being frozen, 12 men and 8 teams on drag scrapers and plow were engaged G days of 10 hr. The haul was 50 to 75 ft. The output was 50 cu. yd. per scraper- day, and 44 cu. yd., per team-day, including plow teams. Based upon the author's experience we have the following: Cost Rule for Drag Scrapers. To find the cost per cu. yd. of average earth (ty cu. yd. per load) moved with drag scrapers, add together the following items: ^-hour's wages of team with driver and plowman for plowing. %-hour's wages of team with driver, lost time loading, dump- ing and extra travel in turning. J^Q-hour's wages of laborer loading scrapers. %-hour's wages of team with driver for each 100 ft. of " lead," for hauling. With wages at 30 ct. per hour per man and 15 ct. per horse this rule becomes: To a fixed cost of 16 ct. per cu. yd. add 6.7 ct. for each 100 ft. of "lead." Fairly tough clay, hard to load, will cost one-third more, whereas easy sand or loam will cost one-third less. Cu. yd. per Lieaa in ft. scraper-hr. 25 5.1 50 4.5 75 4.0 100 3.6 125 3.3 150 3.0 The " lead " is the distance from center of cut to center of fill, in a straight line. Cost of Excavating a Cellar with Drag Scrapers. Engineering and Contracting, Jan. 27, 1009, gives the following'. The follow- ing costs are for cellar excavated in stiff clay. The depth of the excavation was 4} ft., the building being 30^ x 33 ft., with an angle 5 x 16 ft., cut out of one corner. The number of cubic yards was 155. The costs given include the expense of trunning up the sides. The clay was plowed and then excavated with drag scrapers, the excavated material being dumped on the sides of the bank. At first two teams were used, and an extra man for loading the scrapers. When most of the material was exca- vated only one scraper was used, and one of the three men was put to work dressing down the sides with a pick. A runway excavated for the scrapers to enter the pit contained 3 cu. yd., making in all 158 cu. yd. SCRAPERS AND GRADERS 259 The cost was as follows: 85 hr. team with driver at 50 ct $42.50 72 hr. laborer at 15 ct 10.80 Total $53.30 The cost per cu. yd. was: Team work $0.269 Labor 0.068 Total per cu. yd $0.337 This cost could have been reduced by working three scrapers in the gang instead of two, and then one, and by employing an extra man to keep down the sides. With only two scrapers the pace of the teams was slow. This is shown by the fact that only 1.86 cu. yd. of material was moved by a scraper per hour, when at least 3 cu. yd. should have been excavated. Then with only two scrapers, there were times when only one scraper was at work when plowing was being done. With three teams the pace would have been much faster. It would also have been possible to have worked one team overtime and thus have had most of the plowing done when it would not have interfered with the regular work of the scrapers. The cost per cubic yard should have been from 3 to 5 ct. less than it actually was. Cost of Grading a Railroad Siding. The following cost in connection with a lead refining plant at Grasselli, Ind., are taken from Engineering and Contracting, Mar. 12, 1913. About one mile of railroad grading was necessary for the trackage serving the plant. All the material was sand and was handled by slip scrapers. Very little plowing was necessary. The length of haul averaged about 200 ft. and the maximum haul was about 400 ft. The teams and scrapers with driver were paid 35 ct. per hour. Common laborers received $1.75 per day of 10 hr. The work was done between March 7 and April 28. The average number of teams per day was 9.8. Excavation, cu. yd. 15,658 Total labor cost $1,866.00 Cost per cu. yd. ct 11.9 A " Dirt Sucker " for Making Fills Over ' Marshy Ground. Engineering Record, July 3, 1915, gives the following: For making fills across marshy ground in connection with Idaho State road work, a device called a "dirt bucker," is used. It consists of an ordinary fresno scraper fitted to the forward end of a frame supported on two wheels in the rear, similar to that 260 HANDBOOK OF EAPxTH EXCAVATION of a " hay bucker " such as used on western ranches for moving hay from the field to a stacker. The material is pushed ahead of the team by the frame in making 111 Is across wet, marshy places too soft to hold up the horses. The dirt is first dumped at the end of the fill and the " bucker " is simply used for pushing it ahead, taking the place of dump men. According to Edward S. Smith, Idaho State highway engineer, it has proved very effective and economical. Grading Across Sloughs with a Push Scraper. The following is from an article by L. V. Martin, appearing in Engineering and Contracting, May 7, 1919. During the past 5 years it has been Fig. 5. Pushing the Grade with a Bulldoser. hi *\; U) vj;f> -vi.|,r.7.i*. f.-r/iVs'Vi ..rni*l.I none the writer's task to grade across a large number of pot holes, sloughs and peat bogs, over which it was impossible to drive teams. These have varied from a few feet in length to a length of 3,000 ft. in one extreme case. During this work the writer has made some deductions as to costs and methods that may be of interest to contractors and engineers. The most common method of procedure is by what is termed bull-dosing or pushing the grade. This method is particularly adapted to sloughs containing standing water and to short stretches of bog. The grade for this work should be carried from 40 to 60 ft. wide at the base; or in the case of standing SCRAPERS AND GRADERS 261 water to a minimum width of 40 to 45 ft. at the water level. Wagons or scrapers are dumped as close to the edge as it is possible to drive the teams and the dirt is then pushed ahead by the bulldoser, as shown in the illustration. A good operator on the bulldoser can handle the dirt from 5 to 6 teams on an average haul of 500 ft., and more as the length of haul increases. With a good operator little time is lost over a straight haul on good ground. The outfit shown was pushing for five No. 2 wheelers on a 400-ft. haul. A heavy steady team is required to handle this pusher. The actual cost per yard over straight haul dirt with a good operator should not exceed 2 ct. per yard, and may even run below this. Unless dirt can be sent both ways from the cut, however, or the fill is long enough to use the full outfit, an elevating grader is not worked at full capacity and the extra cost per yard on this account will be raised to perhaps 6 ct. additional as a maximum. The outfit shown in the picture was a home-made affair con- sisting of the front wheels of a dump wagon, a straight telephone pole 8 in. at the butt and 20 ft. long, and a push board braced as shown, shod with a 3-in. by ^-in. iron edge on the bottom. It was so made that the pole with board attached could be removed in a few minutes from the wheels and loaded on a wagon. These outfits can, however, be bought from any road machinery firm. This method is much superior to and cheaper than the old one of having shovelers at the end of the grade pushing the dirt off with a shovel. The Fresno Scraper. The scraper shown in Fig. 6 embodies several features in its construction that have made it a favorite tool for scraper work on the Pacific Coast. The chief peculiarity of the device, aside from its general shape, compared with the ordinary drag scraper, is the arrangement of shoes or runners on which it travels when empty. This scraper was probably first made at Fresno, Calif., whence its name. In loading and when traveling loaded the scraper travels on the bottom of the bowl, which is made very heavy, being a plate of %-in. plow steel, having no runners in the shape of projecting plates or strips. In dumping, the scraper is raised by the rear handle until it rests on the traveling shoes so that the load spills back under the edge of the bowl which is 'raised off the ground as shown. By varying the height to which the handle is raised the opening under the edge may be made almost any height from an inch up to the full opening shown; this possibility is of particular value in leveling work, since the load can be distributed in a layer of almost any desired thickness. A rope is customarily fastened to the handle. This 262 HANDBOOK OF, EARTH EXCAVATION is used to prevent the scraper from dumping prematurely, and is allowed to drag when not in use. The bowl fills more rapidly if drawn across the furrows than if hauled longitudinally with them. The sizes and capacities are given in the accompanying table. The actual capacities Fig. 6. The Fresno Scraper. given are for work in average earth on uphill or level hauls. The loads are often from 50 to 100% greater on downhill hauls. No. 1 scraper is generally used, and requires four horses or mules. FRESNO SCRAPERS Size No. 1 No. 2 No. 3 Horses Length of cutting Capacity Listed Actual required edge 5 cu. ft. cu. ft. 4 5 18 9.54 3 4 14 7.43 2-3 3.5 12 6.36 Weight Ib 275 250 Rules for Cost with Fresno Scrapers. The ordinary four-horse fresno scraper has a bowl 13 in. high, 18 in. wide and 5 ft. long, giving a struck measure capacity of slightly more than 8 cu. ft.; but in almost any soil, except dry, running sand, the earth will heap up 6 or 8 in. above the top of the bowl, and will extend quite a distance beyond the front of the bowl. One carefully measured fresno load of clayey earth contained 19 cu. ft. of loose earth, which compacted to 16^ cu. ft. when rammed in 4-in. layers in a box. Several other large loads gave almost the same results after being hauled 100 ft. over a level road. Mr. Geo. J. Specht has stated that on a downhill haul, loads will average 35 cu. ft. and occasionally run as high as 44 cu. ft. However, this could only occur with light, damp soil and on a SCRAPERS AND GRADERS 263 downhill pull where much material could be drifted ahead of the fresno scraper. We have never measured any loads of that size. On level hauls, or on uphill pulls, it is not ordinarily safe to count on more than % cu. yd. (measured in cut) per load, al- though under favorable conditions the average load may be 25 to 50% greater, while under unfavorable conditions it may be 25% less. If the delays in loading and dumping are excluded, the team can be counted upon to travel about 200 ft. per minute. It requires some room in which to manoeuver scrapers of any kind, no matter what method of handling the teams is adopted. Hence one must not measure the average distance in a straight line from the center of the cut to the center of the fill, and call that the average haul, for that is the average " lead," which is considerably shorter than the actual haul. r'^.u.'j In average earth the daily output is as follows when the load averages % cu. yd. Cu. yd. per " Lead " in ft. fresno, 10 hr. 50 ................................... 120 100 ................................ ... 100 , 150 ................................... 87 200 ......... .......................... 75 ::::::::::::::::::::::::::::::::::: 350 ................................... 55 400 ................................... 50 ,/,,ii i KA We have never measured any fresno loads that had been hauled as far as 400 ft., and we doubt very much whether fresno loads hauled that distance would average as much as ^ cu. yd., due to the loss that occurs en route. Cost Rule. To find the cost per cubic yard of average earth (% cu. yd. per load) moved, -with fresno scrapers, add together the following items: ^-hour's wages of 2-horse team with driver and plowman for plowing. %5-hour's wages of 4-horse team and driver, lost time loading; and dumping fresno, and extra travel in turning. i -hour's wages of 4-horse team and driver for each 100 ft.. of " lead " for hauling. The " lead " is the distance in a straight line from the center of cut to center of fill. With wages at 30 ct. per hr. per man, and 15 ct. per hr. per horse, this rule becomes: To a fixed cost of 10.5 ct. per cu. yd. add 3 ct. per 100 ft^ of " lead." 204 HANDBOOK OF EARTH EXCAVATION For tough clay add one-third to this cost and for easy sand or loam deduct one-third. Each driver is assumed to load and dump his own fresno. Cost with Fresnos in Arizona and Cost of Trimming Slopes. Engineering and Contracting, Oct. 2, 1907, gives the following: The following is an example of fresno scraper work, done in Arizona in 1894, under one of the editors of this journal. The scrapers were used in grading a railroad bed, the cuts being 10 ft. wide and the embankments 8 ft. wide. The road was narrow gage. Thirteen miles of roadbed were graded, the yard- age moved being 70,000, or 5,400 cu. yd. per mile. The contractor managed his own work, having only foremen in charge of the various gangs directly under him. One man kept the time books, attended to the commissary and also acted as bookkeeper. In this way the general expense account was a small one. The wages paid were as follows: Time keeper, $50 per month and board. Foreman, $3 per 10-hr, day. Foreman, $2.50 per 10-hr, day. Drivers, $1.70 per 10-hr, day. Laborers, $1.75 per 10-hr, day. The men were charged 75 ct. per day for board. The horse feed was hauled by the contractor's teams from his own ranch, and he estimated that the entire cost of feeding and caring for a horse per day averaged 75 ct. This makes a charge for teams as follows: 4-horse fresno scraper, team and driver $4.75 2-horse drag scraper, team and driver 3.25 4-horse plow, team and two men 700 6-horse plow, team and two men 8.50 The charge for the plow includes an allowance of 50 ct. per day for the use of plow and repairs. It was very difficult for a six-horse plow to break the first foot of earth, but, after reaching that depth, a four-horse plow did the plowing easily. The work consisted of shallow cuts, not over 5 ft. deep; but one cut, about 1,000 ft. long, was 15 ft. deep. More than half the roadbed was embankment, ranging from 5 ft. to 30 ft. fill, the average being from 8 to 10 ft. high. The contractor hauled the material from the cuts into the em- bankments when the lead did not exceed 200 ft.; beyond that distance he wasted the material from the cuts and borrowed for the embankment at his own expense. He considered this cheaper than to haul it. No record was kept of this extra yard- age, a he was paid for the cross section quantities, as though SCRAPERS AND GRADERS 265 he had made the hauls. Fig. 7 shows the manner of making an embankment 10 ft. high. The ditches are plowed on each side of the embankment leav- ing a berm between the ditch and the toe of the slope. The scraper is loaded in one ditch and pulls onto the embankment keeping straight ahead, crossing the ditch on the other side and turning. Then starting back and taking another load the opera- tion is repeated. For an embankment 10 ft. high, this gives a " lead " of about 40 ft., and a distance to be traveled for each load of 100 ft. The amount of earth pushed ahead in such a short distance is very large, but the haul is always uphill for the load. Each team has its own men, the scrapers not being operated in gangs as with wheelers and drags, but in separate runs side by side, and, by so doing, a certain pace can be set and maintained, as the foreman can see at a glance when all the scrapers are not being loaded at one time. Fig. 7. Shape of Embankment Built with Fresno Scrapers. The driver loads and dumps his own scraper, which effects a decided saving in loading and dumping, as compared with wheel scrapers. A rope on the end of the handle makes this operation easy, the scraper, being balanced on the two arch springs in front, dumps as soon as the lever is lifted. It rides in this position to the pit, and then a jerk on the rope throws the pan back on its bottom ready for loading. The driver handles his four horses thus : The two outside horses have a " jockey stick " tied to their bits, and each horse's bridle is fastened to the adjoining horse's bridle by a short strap or raw-hide string. The two reins are each divided into two lines, one line going to each horse's bridle, the lines from one rein going to one outside horse, and to the second outside horse from it. Thus the left hand rein putts the left hand out- side horse and the right hand inside horse, those two guiding the other two by the bit straps. The right hand rein controls the other two horses. No attempt was made to shape the embankment to the dotted lines as shown in Fig. 7, but the scrapers heaped up the dirt 266 HANDBOOK OF EARTH EXCAVATION as shown by the heavy lines, and left it so, until the dressing up gang finished off the roadbed. On the highest embankments the Fresno scrapers could not be worked in topping off the embankments to good advantage, owing to the climb necessary to be made from the bottom of the ditch to the top of the bank, so drag scrapers were used for this work. Since no separate record was kept of this drag scraper work, it will have to be included with the work done by the fresno scrapers. The cost of the work was: Per cu. yd. General expense , $.003 Plowing 020 Scrapers 050 Dressing roadbed 005 Total cost $.078 At 5 ct. per cu. yd. for the fresno work, this means 95 cu. yd. moved per scraper per day. If allowance is made for foreman, which is included in the cost of 5 ct., this yardage would be in- creased to about 105. This amount would be further increased if the drag scraper work could have been separated, and if the additional yardage wasted from the cuts had been measured. It must be remembered that some time is lost by the fact that plowing cannot go on as the scrapers are working, when the latter are handled in the manner described. Hence, when a " plowing " is cleaned up, the scrapers must be moved to another section that has been freshly plowed. A point of interest was the method of dressing up this work. Only one man with a pick and shovel was used on the job. He did the work necessary on the slopes, although by careful plowing these were brought down in good shape as the cuts were exca- vated. He also shaped up the roadbed in the cuts when the scrapers left small places that it did not pay to hold teams to do. All the rest of the dressing work was done by a foreman and three drag scrapers. They took out any excess material left in the cuts and smoothed over the bottom whenever possible. They leveled the embankments down to the proper grade, and, if more material was needed on the bank, they brought it up from the side ditches, see Fig. 7. A man with some little instruction can become very expert in dressing a roadbed with a scraper in this manner. He holds the drag scraper at various angles, cutting off high places and filling up low places as desired. This trimming work cost ^ ct. per cu. yd. of material moved and not quite a % ct. per sq. yd. of roadbed. About } of this cost was for the man using a pick SCRAPERS AND GRADERS 267 and shovel and not quite % was for the foreman who manipulated the scraper. This cost of trimming is quite low. It will compare very favorably with trimming done by a road machine and other leveling apparatus. As compared with trimming done by hand on railroads, it is from ^ to ^ cheaper. Cost Data on Railway Work in Mexico. The actual cost of work to the contractor on the Cananea Rio Yaqui and Pacific Ry. in 1907 was studied by the company's engineers under Howard Egleston. From the results of their findings, reported by him to Engineering and Contracting, Oct. 18, 1911, the fol- lowing is abstracted: Camp No. 2, which made the best showing, had ideal fresno work. With the exception of a shallow cut of 280 meters, it was all embankment work, varying from nothing to a maximum of about 8 ft., all material being taken from borrow pits alongside. The work of Camp No. 3 was similar, except that part of it con- sisted in a fill through swampy ground which had to be built with wheelers. Camp No. 1 worked in a high embankment tak- ing material from borrow pits at the bottom of the em- bankment. The mules used were all Northern animals. Among the idle teams shown in the table are included for each camp from two to four horses used by the camp foreman and corral boss. While by no means idle these animals could not well be charged to any of the productive outfits. Mexican drivers were used, and with training they handled the teams well, but it was difficult to keep them steadily at work. All grading on this Mexican work was done by force account, the contractors receiving a percentage of the cost to pay them for superintendency. The contractors executed the work as they thought best; they furnished such machinery as they thought desirable, and the company paid them rent for the same.' They furnished all animals needed at a fixed rate of hire per day. The commissary was managed by them on a percentage. The accompanying tables are figured in Mexican money. In comparing prices given with similar items in the states these items should be cut in two, as the Mexican dollar equals only 50 ct. Wages All Outfits. Camp Foreman $200, Grade Foreman $150, Corral Boss $120, Blacksmith $200, Harness Makers $150, Cook $90, Cook's Helper $50, Teamsters $100, Watchman $80 per month. Camp laborers $1.75, Grading laborers $1.75, Fresno and wheeler driver $2.50, Plow drivers $4, Plow holders $4 day, Carpenters $8 per day. 268 HANDBOOK OF EARTH EXCAVATION GRADING BY OUTFIT NO. 1 FOR 13 DAYS Earth Handled 5,595 cu. m. 110 Head of Stock Distribution w Foremanship $0.04 ii.iiii'" General camp expenses 08 Plowing 09 Moving dirt .39 Freighting 04 Rentals wagons and buckboard 07 Idle animals 07 $0.78 Total cost per cu. yd., U. S. money $0.30 No loose or solid rock on this work. No explosives used. Work consisted of both cut and embankment. Average amount dirt moved per day per fresno, 25.34 cu. m. 31 plows used one day at 60 ct $ 18.60 220.75 fresnos used one day at 50 ct 110.38 1 slip used one day at 50 ct .50 wheelers used orie day at 80 ct .00 18 wagons used one day at $1.00 18.00 Total cost hay and barley, $870.00 -=- 715 team-days gives cost of feed per team-day, $1.22, or per animal-day, 61 ct. Mexi- can money. Team days working 593 Team days idle 122 Team days total 715 Team hire per day $1.80 Team feed per day 1.22 Team cost per day > $3.02 GRADING BY OUTFIT NO. 2 Earth handled 10,136 cu. m. 117 head stock. Ct. per Distribution cu. m. Foremanship $0.03 General camp expense 05 Plowing 08 Moving dirt 23 Freighting 02 Rentals wagons and buckboard 01 Idle animals .06 $0.48 Total cost per cu. yd., U. S. money $0.18 No loose or solid rock on this work. No explosives used. All embankment except 280 cu. m. shallow cut. The higher wages paid prior to 10th inst. would increase cost only $24.12, not enough to alter rate per cu. m. It is, therefore, not shown. Idle team-days 216.5 37.5 plows used one day at 60 ct $ 22.50 236.5 fresnos used one day at 50 ct 118.25 1 buckboard, 10 wagons, % mo. at $30.00 165.00 Total team-days 877.5 Work team-days 661.0 Total cost of hay and barley, $1,045.76 -f- 877.5 team-days gives cost of feed per team-day, $1.19, or per animal-day, 59V& ct. Mexican money. SCRAPERS AND GRADERS 269 Of teams working 22% were on plows. Of teams working 71% were on fresnos. Of teams working 7% were on wagons freighting. Team hire per day $1.80 Feed per day 1.19 Total $2.99 Average days work per fresno-team, 42.86 cu. m. GRADING BY OUTFIT NO. 3 Earth Handled 5,837 cu. m. 77 Head of Stock Ct. per Distribution cu. m. Foremanship $0.036 General camp expense 048 Plowing 088 Moving dirt 250 Freighting 016 Rentals wagons and wheelers . 041 Idle animals 054 $0.533 Total cost per cu. yd., U. S. money $0.20 Cost of handling dirt per cu. m., .533 ct. Mexican money. No loose or solid rock on this work. Alternating cut and embankment. Average amount dirt moved per day fresno and wheeler, 41.54 cu. m. 30 plows used one day at 60 ct $ 18.00 117.5 fresnos used one day at 50 ct 58.75 2.5 slips used one day at 50 ct 1.25 23 wheelers used one day at 80 ct 18.40 6 wagons used one day freighting at $1.00 6.00 Total cost, hay and barley, $646.64 -=- 481^ team-days gives cost of feed per team-day, $1.34, or per animal-day, 67 ct. Mexican money. Team days working 380.75 Team days idle 100.50 Team days total 481.25 Team hire per day $1.80 1 team feed per day 1.34 Team total cost per day $3.14 A cu. m. is equal to 1.31 cu. yd., so the cost of this work expressed in cu. yd. is 76.5% of the cost here given. A Low Cost of Fresno Work. Walter N. Frickstad in Engineer- ing and Contracting, Nov. 3, 1909, gives the following: The usual practice is to operate fresno scrapers in runs of three to eight, according to length of haul. A laborer .to load usually works with each run. But in light ditch work frequently each team works independently and the driver loads his own scraper. Except in finishing a bank, or in other special cases, the driver dumps his own load. The fresno is generally limited to a haul of 200 or 300 ft., though of course the nature of the contractor's available equip- ment frequently modifies that. It requires less time and labor 270 HANDBOOK OF EARTH EXCAVATION to load and unload than does a wheeler, but the expense of the two extra horses balances those items when the haul exceeds 200 or 300 ft. It is especially useful on highways, on light railroad work, on irrigation and drainage ditches where the cut makes the bank or is wasted, and for loading large cuts. As with all methods of excavating earth, the output varies widely according to the conditions. The writer has records rang- ing from 28 to 130 cu. yd. per scraper per day. The cases given below are fairly typical, however. The first four cases relate to work done by contract on the Truckee Supply Canal, for the Reclamation Service, near Wadsworth, Nev., in 1904. In these cases, the wages of drivers and laborers were $2 per 8-hr, day, rent of horses $10 per month, being about 40 ct. per working day, plus 40 ct. for feed. A fresno and harness is counted at 10 ct. per day, plow and harness at 20 ct. All camp and gen- eral expenses are excluded, and no deduction is made for profit on men's board. Board was 75 ct. per day, including days of idleness. All working day are of 8 hrs., but the horses were driven accordingly. Following is a record made under most favorable conditions, in January, 1904. Weather, clear and cold; soil dry, breaking readily, being loam, sand and clay in irregular beds; earth moved from ditch to make the base of both banks of canal, extreme lift being about 10 ft.; a small amount of earth hauled as much as 200 ft. : Foreman, 15 days at $4.50 $ 67.50 4-horse frosno and driver, 84 days at $5.30 445.20 6-horse plow, driver and holder, 13 days ajb $9 117.00 Labor, clearing, helping plow holder, etc., 30 days at $2.. 60.00 Labor, loading scrapers, 32 days at $2 64.00 Total, 10,219 cu. yd $753.70 Deducting $38 as the cost of clearing, the cost per yd. was 7 ct. per cu. yd. It shows 122 cu. yd. moved per scraper per day, and it is certain that the average would have been 130 cu. yd. had all hauls over 100 ft. been eliminated. Owing to careless dump- ing, however, and the resulting large amount of sloping, the final cost was much larger than shown here. The second case is typical of a large cut, being the approach to a tunnel. It covers December, 1903, January, February, March, April and part of May, 1904; weather generally clear and cold, except few warm days in April and May; soil dry solid silt and cube clay, which would not pile high in scraper; average force employed, 8 fresno first two months, afterwards 12; excava- tion on side hill, extreme cut over 60 ft., with 15 ft. to 30 ft. on low side; material wasted into gulch below, much of it 60 ft. SCRAPERS AND GRADERS 271 below grade of canal; most of material hauled downward about 30 ft. horizontally 100 to 200 ft. Actual wages varied from these figures, especially plow driver and holder, but are held uniform for comparison. Foreman, 4% months at $80 $ 4-horse fresno and driver, 1,192 days at $5.30 6,317.60 4-horse plow, driver and holder, 74 days at $7.40 547.60 6-horse plow, driver and holder, 47 days at $9 423.00 Labor, loading, estimated 240 days at $2 480.00 Labor, sloping and miscellaneous, estimated 184 days at $2 368.00 Labor, helping plow holder, estimated 50 days at $2 100.00 Total, 71,567 cu. yd $8,616.20 This is almost exactly 60 - cu. yd. per fresno per day at a cost of 12 ct. per cu. yd. This cut was not considered to have been well managed. Six or more foremen were in charge suc- cessively, and the work dragged noticeably. Other similar cuts, better managed, averaged 65 to 70 cu. yd. per scraper per day. Following is a record of extremely difficult conditions. The earth was thoroughly mixed with stone, in all sizes up to 5 cu. ft. The greater part of these had to be taken to the outer edge of the embankment. The material was hard to plow and harder to load. It was all used in making the banks, mainly on one side, with little longitudinal haul. Foreman, 16.5 days at $3 $ 49.50 4-horse fresnos, 61.5 days at $5.30 325.95 2-horse stoneboat, 11.2 days at $3.65 40.88 4-horse plow, etc., 6.5 days at $7.40 48.10 6-horse plow, 5.2 days at $9 46.80 Labor, loading scrapers and stoneboat, 76.2 days at $2... 152.40 Total, 3,800 cu. yd $663.63 Supposing the 11.2 stoneboats to have been equal to 3^ fresnos, this would give 58.5 cu. yd. per day per fresno. The cost would be about n% ct. per yd. This work was well directed, and showed a surprisingly high yardage for the force employed, but the long haul accounts for it. Following is a record that illustrates the effect of haul. Weather was dry and cold, soil dry sand and silt; haul averaging 600 ft.; foreman the same as the above. Foreman, 18 days at $3 $ 54.00 4-horse fresno and driver, 170 days at $5.30 901.00 1-horse plow, driver and holder, 9 days at $7.40 66.60 Labor, 49 (probably 22 loading and 27 finishing) aj $2. 98.00 Total, 28.8 cu. yd. per fresno per day $1,119.60 Following is a more itemized record of work during April, May and June, 1906, near Fallen, Nev., by Government forces, on an irrigation canal. Weather hot and dry; soil, mainly com- pact sand, with some gravel, loam and hard clay; ditch about 272 HANDBOOK OF EARTH EXCAVATION 20 ft. wide on the bottom, slopes, 2 to 1, hank 7.5 ft. above grades, 6 to 12 ft. wide on top, location generally along a Hat sidehill; banks generally made from cut, but one hill had a cut of 20 ft. and the material was wasted beyond a 50-ft. berm or hauled 200 or 300 ft. to reinforce the banks across the adjoining depressions. Another short hill was hauled an average of 150 ft. either way. The right of way was cleared of light brush, and berm plowed before building banks, the slopes were carefully trimmed, and the bottom finished to grade stakes. The working day was 8 hr. The small amount of finishing labor shows how well that work can be done by scrapers. Foreman $ 101.00 Sub-foreman % 6.00 4-horse fresno drivers, $2.25 692.42 Scraper holders, $2.25 241.K1 6-horse plow driver, $2.75 62.55 Plow holder, $2.75 68.05 Laborers, cleaning, finishing, $2.25 16.87 Horses (hired), $0.333 day 464.83 $1,650.03 Cu. yd. excavated 27,629 Cu. yd. per scraper day 89.75 Following is the July record of the same outfit, on a piece of ditch with less haul and less deep cutting. Labor was scarce, very unsatisfactory, many teams were idle each day, and the foreman was away on a spree for the first twelve days. Ap- pended also is a complete record of the camp expenses, all of which are chargeable to this work. The latter indicate how total expense may differ from field or excavating expense. Excavating Expense: 18 days foreman at $12.50 per mo $ 67.50 34 days sub-foreman at $95 per mo 107.67 354% days 4-horse fresno driver at $2.25 798.19 2 days 2-horse fresno driver at $2.25 4.50 4 days 4-horse tongue scraper driver at $2.25 9.00 1% days 2-horse tongue scraper driver at $2.25 3.93 119% days scraper holder at $2.25 268.88 431/2 days 6-horse plow driver at $2.75 119.62 43% days 6-horse plow holder at $2.75 119.62 1% days 2-horse tongue scraper holder at $2.25 .... 3.93 1,691 days horses at 33% ct 563.67 $2,066.51 Excavation (about), 30,000 cu. yd. Excavation per scraper, 84.3 cu. yd. per day. (2-horse fresno counted as one-half of 4-horse fresno. Tongue scrapers not included, as their work was confined to finishing.) Managing Force: 13 days superintendent at $145 per mo $ 60.81 1 month timekeeper lOO.f 1 93 days horses at 33% ct 31.00 $191.81 SCRAPERS AND GRADERS 273 Camp Force: 26% days blacksmith at $3 $ 92.75 15% days cook at $60 31.00 15 days cook at $75 37.50 4V 2 days second cook at $40 5.99 38% days flunkies at $35 44.91 13y 2 days labor at $2.25 30.37 42 days 6-horse freight teamster at $2.75 115.50 2% days 4-horse freight teamster at $2.25 5.62 17 days 4-horse freight teamster at $2.50 42.50 1% days 2-horse freight teamster at $2.25 3.37 396 days horses at 33^ ct 132.00 1,594 days idle horses * at 33% ct 531.33 Subsistence 472.00 Supplies 71.16 Forage 1,634.33 $3,250.33 * Idle horses includes working stock on Sundays and holi- days, being six days. Deduct board of men at 75 ct. per day, except Superintendent and kitchen force, about $730. Another contractor, in the spring of 1905, excavated 125 to 130 cu. yd. per day per fresno. The exact record of labor is not at hand, but it can be approximated. The soil was sand and light loam. The cut generally made the banks. The ditch was nar- row, and ranged from 6 to 7} ft. deep, from bottom grade to top of bank. Scrapers worked singly, going down one bank and up the other alternately. Each driver loaded and dumped his own scraper, except one finishing scraper. A two-horse plow, without holder, loosened the earth for 10 to 12 scrapers. The contractor paid $2.25 per day, and worked 8 hr., while others near by paid $2.00 and worked 10 hr. He therefore had the best men available, and forced both men and horses to their limit. He was fully of the opinion that he would have done no better by working 10 hr. per day. The excavation cost, in- cluding practically all the finishing, for 125 cu. yd. per fresno per day might be computed as follows for a maximum : 4 horses, fresno and driver $5.30 1-10 of 2-horse plow and driver at $3.95 0.395 1-10 of loader 0225 1-10 of foreman at $4 0.40 Total per scraper day $6.32 This is 5.06 ct. per cu. jd. The Oakland Revolving-Bucket Scraper. Engineering News, Oct. 21, 1915, gives the following: A novel scraper developed from the fresno type is bemg marketed by the Graves-Spears Road Machinery Co., of Oakland, Calif. Four sizes are made with 5-, 6-, 7- and 8-ft. buckets. 274 HANDBOOK OF EARTH EXCAVATION A long steel bucket or bowl is pivoted in a stiff steel frame which is carried on shoes forward and wheels at the rear. The driver rides, loading and dumping- with a foot lever. He does not have to pull the bucket back into place, as it revolves and locks when it comes into loading position. For grading it can be held at any angle desired. This scraper sells at from $75 to $200. It is claimed that one 6-ft. Oakland scraper will move more earth than two 5-ft. fresno scrapers. Fig. 8. Revolving Bucket Scraper. Wheel Scrapers. The following has been taken from catalogs, excepting the last two columns, which the author has added: Actual struck Weight Cata- measure Sire of Bowl of logue cu. ft. 1 Actual wheeler No. Depth in in. Width in in. Length in in. wheeler inlb. capacity cu. ft. of loose earth place measure 1 12 36 36-36 340-450 9-10 7.5-9 6-7.2 9 1 -13.5 38 33-37 475-500 12-13 8.75 7- 2% 13.5 38 41 575 14 12.15 9.7 3 16 42-44 40-41 625-800 16-17 15.5 12.4 i Actual place measure, capacity 20% less than loose measure. Large wheel scrapers, even in light soils, and small " wheelers " in tough soils seldom leave the pit full of earth, but at the back end of the bowl there is usually a wedge-shaped space unfilled where the earth slopes up from the bottom of the pan on a 1.5 to 1 slope. Unless front end gates are used on large scrapers, a similar unfilled space exists at the front end of the bowl, before the team has traveled far, thus reducing the capacities given in last column by 2 to 3 cu. ft. The author has found the average SCRAPERS AND GRADERS 275 load (place measure) carried by wheelers is as follows: No. 1, 0.2 cu. yd.; No. 2, 0.25 cu. yd.; No. 2%, 0.33 cu. yd.; No. 3, 0.4 cu. yd. These loads, however, can be materially increased by the simple expedient of having men with shovels to fill the bowl heaping full when the soil is such that the team cannot fill the bowl. The longer the haul, of course, the better it will pay to so fill the bowl. A snatch or snap team is generally used with a No. 2 wheeler Fig. 9. Wheel Scraper Made by American Steel Scraper Co., Sidney, Ohio. and always with a No. 3, to assist in loading, but even with a snatch team it is impossible to fill the bowl in tough clay. In such cases by all means use shovelers. With wheelers, as with drag scrapers, add 50- ft. to the actual " lead " for turning and maneuvering the teams, equivalent to } minute of team time each round trip. Another ^ minute is lost in loading and dumping, and still another'^ minute help- ing load the scrapers. The lightest No. 1 wheelers made are to be recommended where leads are very short and rises steep, that is wherever drag scrap- 276 HANDBOOK OF EARTH EXCAVATION ers are ordinarily used, for they move earth -more economically than drags. Where soil is very stony, or full of roots, drag scrapers are to be preferred, since they are more easily and quickly loaded under such conditions. The method of handling No. 1 wheelers is the same as that above given for drags. When actually walking a wheeler team averages 200 ft. per minute. Rules for Costs with Wheeler. The following rules of cost with wheelers are based upon careful timing of individual teams Fig. 10. Wheel Scraper After Load is Dumped. checked by large excavations. The rules, moreover, will be found to agree closely with published data where conditions have been similar. Rule I. To find the cost per cu. yd. of average earth moved with No. 1 v/heel scrapers (% cu. yd. load), add together the following items: ^-hour's wages of team with driver and plowman for plowing. %-hour's wages of wheeler team with driver, " lost time " load- ing and dumping and extra travel in turning, wages of man loading scraper. SCRAPERS AND GRADERS 277 y l2 -hour's wages of wheeler team with driver for each 100 ft. of " lead " for hauling. With wages at 30 ct. per hour for men and 15 ct. per hr. per horse, the rule becomes: To a fixed cost of 16.5 ct. per cu. yd. add 5 ct. per cu. yd. for each 100 ft. of " lead." Rule II. To find the cost per cu. yd. of average earth moved with No. 2 wheel scrapers (^4 cu. yd. load), using no snatch team, add together these items: ^-hour's wages of team with driver and plowman for plowing. %-hour's wages of wheeler team with driver for " lost time " loading and dumping and extra travel in turning, 's wages of man loading scrapers, wages of man dumping scrapers. i/15-hour's wages of wheeler team with driver for each 100 ft. of " lead " for hauling. With wages at 30 ct. per hr. for men, and 15 ct. per hr. per horse, this rule becomes: To a fixed cost of 18.5 ct. add 4 ct. per cu. yd. for each 100 ft. of '"lead"; and if a snatch team is required to load add 3.5 ct. more per cu. yd. Rule III. To find the cost per cu. yd. of average earth moved with No. 3 wheel scrapers (% cu. yd. load), using a snatch team, add together the following items: i/ -hour's wages of team with driver and plowman. 3/12-hour's wages of wheeler team with driver for " lost time " loading and dumping and extra travel in turning. % 8 -hour's wages of team with driver for snatch team. ^Q-hour's wages of man loading scrapers. i -hour's wages of man dumping scrapers. i^-hour's wages of wheeler team with driver for each 100 ft. of lead for hauling. With wages at 30 ct. for men and 15 ct. per hr. per horse, this rule becomes: To a fixed cost of 17.5 ct. per cu. yd. add 2.5 ct. for each 100 ft. of " lead." The " lead " is the distance in a straight line from the center of the cut to the center of the fill. For very tough clay add one-third to the above costs, while for easy sand or loam deduct one-third. To estimate the number of cubic yards per hr. per wheeler, add together the " lost time " and the hauling time for the given "lead"; divide the sum into one. Thus, if the "lead" is 150 ft. and the wheeler is a No. 2, we have (by Rule II) % hr. lost time, plus %% X 1.5 or l^ hr. " lost time"; whence the total is l% hr. Dividing this into 1, we get 6<^ 6 O r 3.7 cu. yd. per hr. Hints on Handling Wheelers. Engineering and Contracting, Aug. 28, 15)07, gives the following: In operating scrapers the first consideration is the plowing of the material. This seems a simple matter, consequently it is seldom done properly. If 278 HANDBOOK OF EARTH EXCAVATION the earth will permit, the plow should be set to cut a furrow 10 to 12 in. deep. With such a depth of well broken up dirt the scraper will be heaping full after traveling but a few feet, but if the material is not broken up well and is not plowed deep, the scraper will travel some distance over the ground without getting a good load, for the back half of the pan will not heap itself with dirt unless the loading of the scraper is done quickly and with some snap. The furrows should be kept close together and care exercised that ridges of unplowed ground are not left between them, else the work of loading will be impeded. It is also important that the bottom of the cut should be kept level so that the scraper pan will lie flat and not be tilted to one side, thus taking a load the greater part of which will drop off on the way to the dump. It will frequently pay in stiff, heavy soils to plow the material twice, as this class of earth can be broken up in this manner so as to load the scrapers much faster and easier. Wheel scrapers are generally made in four sizes, No. 1 being the smallest. This size is not used very extensively, because most dirt movers do not seem to appreciate their value. A snatch or snap team is not needed in operating this size scraper. One man also can load it, and two horses can pull it up an in- cline as easily as a drag. These facts make it as cheap to operate as a drag or slip scraper, and it carries a larger load than the largest si/e of the drags. The load, too, can be carried farther. This makes the unit cost of excavation much lower. For short hauls, with loads of 75 to 200 ft., a No. 1 wheeler is not only superior to a drag, but also to a larger size wheeled scraper. In operating Nos. 2, 2^ and 3 wheeled scrapers, a snatch team is necessary to help load the scraper. Most contractors have found that in average earth, or those heavier than average, three horses in the snatch team are better than two, two horses only working well where the soils are light. The three-horse snatch team has become the usual one in most sections. Good results are obtained with it, but much better and more economical work can be done with a four-horse snatch team. Two men are gener- ally used with a snatch team, one to hook and unhook the team to the scraper, and the other to do the driving. With four horses the same number of men are needed. The horses are hitched up in pairs. Four horses will load the scrapers not only quicker, but with a larger load. Their greatest value is in changing from one end of the cut to the other. When loading, the .scraper team should always pull in the direction in which the load is to be hauled. By doing this the SCRAPERS AND GRADERS 270 load is kept in the pan better, for in turning a loaded wheeler on the plowed ground much earth is spilled. Then, too, in narrow cuts the loaded team does not interfere with the empties, which can pass behind the snatch team, turn around, lower the pan in position for loading and pull up behind the snatch team at the proper moment. The scraper team should pull up behind the snatch team which should be backed a foot or two and hooked on. In plowing, the two extreme ends of the row are never plowed as deep or as well as the rest of the row. Consequently in loading there is less dirt to be picked up at the ends, so the work is lighter and easier. With a three-horse snatch team, the snatch team must be used until the last scraper is loaded at the end of the row, then time is lost by all the wheelers, while the snatch team is traveling the length of the cut to start another row. This generally means that the run of the scrapers is interfered with and one team blocks another, so that even with close attention on the part of the foreman it may be some minutes before the teams are again spaced out and moving with clocklike precision. With a four-horse snatch team, however, this loss of time and confusion can be prevented. As the scrapers near the end of the row, and there are not two or three more loads of dirt to be picked up, two horses from the snatch team are sent to the other end of the cut and while one part of the snatch team is finishing up the old row the other part is starting a new row. The light plowing at the ends of the row makes this a quick job, and as the scrapers get into the heavy plowing of the new row, the two snatch teams have been made into one again, and the work is carried on without a break. The saving effected with a four-horse snatch team over a three-horse will generally pay for the extra horse many times over. For most wheeled scraper work, Nos. 2 and 2y 2 are the best sixes to use. Contractors have adopted them for railroad, levee, wagon road, reservoir and other construction. The No. 3 is too heavy, and drags on the horses, especially in sandy or light loam. They are also too hard on a team in loading or in mounting an incline. In some special places they can be used to excellent advantage. When the load is over a good hard roadway, and the excavation is on slightly higher ground than the dump, a No. 3 is no harder on the team and is more economical than the other sizes. In dumping a scraper one man can manipulate the scraper if the team is kept moving at a slow gait. Some contractors however, use two men on their dumps. With but little practice 280 HANDBOOK OF EARTH EXCAVATION a dump man can learn how to hold the pan after he has tilted it, so as to spread and level off each load as it is dumped. This is much easier to do when the load is dumped over the end of an embankment, but when dumping on a level place the dirt can be distributed in from 3 to 6 in. layers without additional work. Scrapers are worked in " runs " according to the length of the " haul." It must be remembered that the " lead " is considered as being from the center of mass of the cut to the center of mass of the dump. The " haul " is the entire distance traveled by the scraper from pit to dump. There should always be enough scrapers in a " run " to keep the loaders and the snatch team steadily at work. Scraper work is ideal when the lead is from 300 to 400 ft. and good work can be done up to 500 to GOO ft., but the cost quickly increases when the distance becomes greater. For this reason an extra price is needed when the leads are long. The extra price paid is termed the " overhaul price," and when it applies to scraper work the free haul should not exceed 500 ft. It is important that wheel scrapers be operated according to a time schedule. An ideal arrangement would be to have the snatch team start at the beginning of the plowed ground. The first wheeler would be driven up to it and the snatch team backed slightly and hooked on. A second wheeler would follow the first at an interval just enough to give the first wheeler time to unhook and drive off, and so on until in its progress from beginning to end of the plowed ground, the snatch team would load all the wheelers. The length of the plowed ground preferably should be such that the snatch team can load each wheeler once without turning, and the number of wheelers used should be sufficient so that the first would be back for its second load as soon as the snatch team had returned to the beginning of the plowed ground and gotten position for loading. This ideal can not always be realized. Reservoir Work in Mass. As giving what is probably a maximum cost we may cite the Forbes Hill Reservoir previously referred to (C. E. Saville in Engineering Xews, May 13, 1902). The material was clay-gravel or hardpan requiring two teams on a pavement plow. A snap or snatch team was used in loading the No. 3 wheelers, two men holding the scraper handles. The haul was 250 to 300 ft. " The wheel scrapers theoretically held % cu. yd., but in the material here excavated only about % cu. yd. could be readily loaded automatically. Under favorable conditions each team averaged 35 cu. yd. per day (of 9 hours?) making 8 to 10 trips per hour." With labor at 15 to 17 ct. and SCRAPERS AND GRADERS 281 team (with driver) at 45 to 50 ct. per hr., the cost of excavating nearly 16,000 cu. yd. of hardpan was: Ct. per cu. yd. Plowing 10.9 Scraping 22.2 Unloading and spreading carefully 7.7 Rolling embankment 3.9 Total 44.7 The cost of stripping 8,700 cu. yd. of loam and transporting to a spoil bank, (haul not given but presumably about the same,) was: Ct. per cu yd. Plowing 3.4 Scraping 14.0 Unloading 0.6 Total 18.0 Bearing in mind the wages the cost was considerably above the ordinary. Railway Work in Iowa. The following is from a paper by Mr. J. M. Brown in Trans, of the Iowa Soc. of Eng., 1885: Mr. Brown's experience has led him to state that only No. 1 and No. 3 wheelers should be used. The author cannot agree with him, believing that No. 2 is the best size for all around work. The following has been abstracted from Mr. Brown's paper: A No. 1 wheeler holds 14 cu. yd. of earth (Iowa) on an aver- age, and one trip in 2 to 2y 2 minutes is the average, where the haul is 100 ft., thus giving an output of 60 cu. yd. in 10 hr. With the following force, 1 plow, 6 wheelers, 3 loaders, 1 dumper, and 1 foreman, the cost was: Ct. per cu yd. Labor, loading, dumping, etc 4.11 Scraping (100 ft. haul) 5.83 Wear of tools 0.39 Total 10.33 With a 100-ft. haul, 6 wheelers; with a 200-ft. haul, 9 wheelers, and with a 300-ft. haul, 12 wheelers (No. 1) are required to move 360 cu. yd. in 10 hr., according to Mr. Brown, at an added cost of about 3 ct. per cu. yd. for each 10p ft. of haul. We believe this 3 ct. per 100 ft. to be erroneous because Mr. Brown has made the average speed of the team too small by failure to subtract lost time at both ends of the haul. Mr. Brown gives the following data for No. 3 wheelers; a snatch team and two men being used to load; 8 wheelers each moving 40 cu. yd. in 10 hr. with a 400-ft. haul. With wages at 15 and 35 ct. we have: 282 HANDBOOK OF EARTH EXCAVATION Ct. per cu. yd. Plowing 1.66 . Holding scraper 1.66 Dumpman 0.50 Foreman 0.70 Scraping (400-ft. haul) 7.77 Wear of tools 0.50 _' Total 12.79 Mr. Brown adds two wheelers for each 100 ft. of added haul, or 2 ct. per cu. yd. per 100-ft. haul, which, we repeat, is erro- neous. Wheeler Work on the Chicago Canal. Extensive data on wheel- scraper work are given in Hill's " Chicago Main Drainage Canal." Excellent papers on the same subject by A. E. Kastl and Mr. E. R. Shnable are to be found in the Journal of the Association of Engineering Societies, Vol. XIV, 1895. From these sources we have abstracted the following relative to costs on the Chicago Drainage Canal: The soil moved by wheelers was a " fairly soft clayey loam," and the average haul was about 400 ft., the material being deposited in spoil banks. On the Brighton Division, Section K, 68,300 cu. yd. were moved in 62 days, the average force being 23.8 men and 36.8 teams with drivers. There were two plows and 24 No. 3 wheelers in use, hence each plow loosened 550 cu. yd., and each wheeler moved 46.1 cu. yd. per 10-hr, day; while the average output, including snatch teams of which there appear to have been about one for every three wheelers, and including plow teams, was about 30 cu. yd. per day per team. For Summit Division, Section E, Mr. Shnable gives the follow- ing: The haul was 400 ft. The number of men engaged is not given, but we have assumed % man per team, which is not far from right. Total Daily aver- Cost, Average exca- age, cu. yd. Ratio of teams ct. Fill, Cut, vation, Per Per Wheelers Wheelers per Stations ft. ft. cu. yd. team whir, to plows to team cu. yd.l 460 to 470 12 8.0 94,879 29.8 42.2 5 1/3 -1 4 4/10-1 15.1 2 470 to 480 12 8.3 98.515 27.1 39.3 4 9/10-1 4 4/10-1 16.6 2 480 to 490 11 7.0 85,761 24.4 35.2 4 8/10-1 4 3/10-1 18.4 2 490 to 500 7 3.4 33,185 35.0 50.1 4 9/10-1 4 4/10-1 12.9 3 500 to 507 7 4.3 19,678 28.3 42.1 4 6/10-1 3 7/10-1 15.9 4 l Assuming 2/3 man ver team. Material : 2 Very stiff blue and yellow clay with a few large boulders. 3 Loamy clay. 4 Stiff clay. The table shows that there were about five wheelers to each plow, hence each plow team must have loosened about 200 cu. SCRAPERS AND GRADERS 283 yd. in 10 hr. ; the hardest section being from Sta. 480 to Sta. 490, where 168 cu. yd. was the average per plow team per day. Doubtless two teams were worked on each plow. One snatch team to every 4.4 wheelers appears to have been the aver- age, or each snatch team loaded about 175 cu. yd. a day at a cost of 2 ct. a cu. yd. Loading Through Traps. Wheel scrapers were used on the Chicago Drainage Canal for loading cars by dumping the earth through a platform into the cars; and similar use of wheelers for loading wagons has often been made elsewhere. The incline approach to the platform need not rise with a less than 20% grade, and may have a width of 8 ft. instead of the 12 used on the Chicago Canal. The cost of such an incline ( 12 ft. wide by 120 ft. long including both approaches) is given at $100 (in 1895). It is not the first cost of the incline, but the cost of moving it that makes this method too expensive ordi- narily; and the shallower the excavation the more frequent the moving of this incline. As an expedient to reduce this cost of moving the incline, the author would suggest that it be made with two wooden stringers (6-in. x 6-in.) under the sills of the bents and that these stringers which are to act like the runners of a sleigh be planed upon the bottom and rest upon cross ties or skids, placed like railroad ties, only farther apart, say 4-ft. c. to c., dressed on top and well greased. Make the flooring as light as possible, using a very small factor of safety, and make the incline in two detachable sections. Ten or a dozen teams will then readily " snake " the incline along over skids laid in advance, and it will be unnecessary to take the incline apart to move it. By study of the foregoing data it will appear that loading wagons by wheelers is cheaper than by shovels, so that if the cost of moving the incline is not great the method is a good one. Wheel Scrapers and a Wagon Loader. The following descrip- tion of the R. C. Ruthaven (Buffalo, N. Y. ) wagon loader is from Engineering News, Apr. 23, 1896. In the operation of this device wheel scrapers were used, dumping on a platform 7x9 ft., in size, 2^-yd. loads were dumped and then the platform was tilted. The operation required 7 sec. to throw the earth in the hopper. From this hopper it was raised by a bucket elevator, having 22 buckets of 2 cu. ft. capacity. This discharged into a bin at the rate of 100 buckets per min. The engine was located beneath the buckets and it also tilted the platform by means of a friction attachment. The machine was mounted on wheels and was 7 x 20 ft. in size exclusive of the tilting platform. When working in stiff clay 35 to 40 wagons holding 2 cu. yd. 284 HANDBOOK: OF EARTH EXCAVATION each were loaded per lir. The saving on street work was 10 ct. per cu. yd. The lorce required and their wages was as follows. Foreman, $3; engineman, $3; fireman, $1.50; two men dumping scrapers, $3; two men loading wagons, $3; one man cleaning up, $1.50; three men loading scrapers, $4.50; 'five scraper teams and drivers, $18.75; one watchman, $1.50; one water boy, $1.00; two plow teams and drivers, $8; two plow men, $3.50; two men on wagon dumps, $3; y 2 ton of coal, $2; total per day, $57. Some 500 to 800 cu. yd. were loaded per 10-hr, day at a cost of 7.1 to 11.4 ct. per cu. yd. Wheeler Work Across a Swamp. Engineering and Contracting, Sept. 4, 1907, gives the following: The following is an example of the cost of scraper work done by one of the editors of this journal on the grade of a new railroad. There were 2,000 cu. yd. in the cut, the " lead " being 700 ft. The work was done in the fall of the year, the weather conditions being very favorable. The material consisted of light red clay and sandy loam, turning into sand in the bottom of the cut. A four-horse plow team with two men was used in plowing at first, but when the sand was struck a three-horse plow team was used. The snatch team, which at first had three horses in it, was also changed to two when the sand was encountered. The embankment was made over a tide-water marsh that in many places would not support a man. In these spots brush was put down, and the embankment was built in layers. The first layer was made by shoveling the dirt ahead of the wheelers. This extra work made it necessary to have four men on the dump, which accounts for the extra cost of dumping. Two men were used to load the scrapers, which were No. 2y 2 wheelers holding ty cu. yd. place measurement. As in many sec- tions only one man is employed to load the scrapers, the cost in this example is doubled. ( The teams were all hired, with no pace-makers owned by the contractors doing the work. The foreman consequently had but little control over the drivers, who, for one reason and another, lost time. One side of the cut was a bluff about 15 ft. high, against which the tidewater washed. The teams could neither plow nor scrape this side of the cut down, so a gang of extra men under a foreman pulled this material down with pick and shovel, mov- ing just enough of it so the scrapers could pick it up. It will be noticed that distributing this cost over the Whole yardage moved, it amounted to 7.2 ct. per cu. yd. The wages paid for a 10-hr, day were: SCRAPERS AND GRADERS 285 Foreman $3.00 Extra foreman 2.50 Scraper team and driver 4.75 4-horse plow team and 2 men 9.20 3-horse snatch team and 1 man 6.00 3-horse plow team and 2 men 7.50 2-horse snatch team and 1 man 4.60 Loaders 1.60 Laborers 1.50 Water boy 1.00 The foremen were paid for every working day in the week whether it was possible to work the teams or not. The rest of the forces were only paid for the actual time they made. An average of seven scrapers were worked each day. The entire cost of the work was: Foreman, 13 9/10 days $ 41.70 Scrapers, 88 3/10 days 419.42 4-horse plowing, 8 days 78.20 3-horse plowing, 3 7/10 days 27.75 3-horse snatch, 8% days 43.00 2-horse snatch, 3 7/10 days 17.02 Loaders, 24 4/10 days 39.04 Dumpers, 43 3/10 days 64.95 Water boy, 3% days 3.50 Total $734.58 Extra men pulling down bank: Foreman, 4% days $ 11.25 Extra men, 88 days 132.00 Grand total cost $877.83 This gives us a cost per cu. yd. as follows: Foreman $0.02 Scrapers 21 Plowing 053 Snatching, .03; loaders, .02 05 Dumping 033 Water boy 001 Total scraper work $0.367 Tearing down bank: Foreman $0.006 Extra men 066 Total $0.072 Grand total per cu. yd $0.439 An analysis of the cost gives us the following information: A scraper team traveled 6 miles per day. They should have covered a much greater distance than this. The plow team loosened 164 cu. yd. per day. This was all that was needed, but much more work could have been done by this team. The snatch team, of course, loaded the same amount. 280 HANDBOOK OF EARTH EXCAVATION They, too, could have handled more yardage, serving the same number of scrapers. The average yardage per scraper was 23, while the average yardage for all teams engaged was 15.5. Four Examples of Wheeler Work on Railways. Four ex- amples of cost of wheel scraper work are given in Engineering mid Contracting, Sept. 25, 1907. They are all work done in grading railroads. The wages paid for a 10-hr, day were: Foreman $3.00 Scraper team and driver 4.75 4-horse plow team and 2 men 9.20 3-horse snatch team and 1 man 6.00 Loaders 1.60 Dumpmen 1.50 Water boy 1.00 The teams were hired, and the fact that work was plentiful in that section of the country made the teamsters very inde- pendent, which helps to account for some of the high cost. A four-horse plow team was used to loosen the dirt, and a three-horse snatch team was used in loading the scrapers. The wheelers were No. 2y 2 , holding % cu. yd. place measurement. Two men were used to load the scrapers, which resulted in quicker loading than where only one man was used. Two men also dumped the scraper, except in Example No. 1 There was no need for this, except that a man could not be made to dump the scrapers without help. This* of course doubled the cost of dumping. All the work was done in the fall of the year, the weather being very good for grading work. Example I. The material in this case was a sandy loam, easily plowed and scraped, so as to make a heaping scraper load. The lead was 260 ft., the distance traveled on each trip by a team being 600 ft. This made a total distance per day for scraper of about 12 miles. The cost was as follows: Per cu. yd. Foreman '. . . . $0.017 Scrapers 138 Plowing 052 Snatching 034 Loaders 018 Dumping .008 Water boy 006 Total $0.273 The average yardage moved per day for a scraper was 34, while per team employed it was 21. Example II. The material on this job was a good clay. Five scrapers were worked in a gang in this example as well as in Example I. The lead was 300 ft., while the average distance SCRAPERS AND GRADERS 287 traveled to the dump and back was about 700 ft., which meant a total distance covered each day by a scraper team was about 12 miles. The cost was as follows: Per cu. yd. Foreman $0.019 Scrapers 158 Plowing 057 Snatching 037 Loaders 020 Dumping 016 Water boy 004 Total ^ $0.311 The average yardage moved per scraper per day was 30 while per team employed it was 19. Example HI. The material in this cut was wet clay, made so by some heavy rains and springs that were struck in the ground. The lead was 400 ft., while the distance traveled on each trip was 1,000 ft., making a total distance traveled per scraper per day of 12} miles. The dump was on marshy land which made necessary an extra laborer on the dump who shoveled dirt ahead of the teams. The cost was as follows: Per cu. yd. Foreman $0.026 Scrapers 216 Plowing 080 Snatching 052 Loaders 028 Dumping 039 Water boy 009 Total $0.450 The number of wheelers worked in a gang was five. The aver- age yardage moved by each scraper was 22, while that per team was 13. Example IV. This material was a fine sand, into which the wheels sank so the scraper bowls dragged on the ground. Six scrapers worked in a gang. The lead was 500 ft., the average distance traveled going to the dump and returning being 1,000 ft., making the distance covered per day for scraper 12^ miles. The cost was: Per cu. yd. Foreman $0.024 Scrapers 222 Plowing 073 Snatching 050 Loaders 026 Dumping 027 Water boy . . ; 008 Total $0.430 288 HANDBOOK OF EARTH EXCAVATION The average yardage moved per scraper was 21^; per team it was 13. The plow teams loosened in the four examples respectively 170, 150, 115 and 125 cu. yd. This did not keep them busy during the day, as they could have readily loosened twice the amount they did. The snatch team could also have loaded a greater yardage. This shows that there were not enough scrapers worked in a gang. The yardage moved by a scraper as the haul is increased was as follows: Cu. yd. 260 ft. lead * 34 300 ft. lead 30 400 ft. lead 22 500 ft. lead 21% It will be noticed that in all cases a scraper team traveled between 12 and 12^ miles per day. It could have been possible to have covered a greater distance. Wheel Scraper Work on a Railroad. Engineering and Con- tracting, Jan. 22, 1908, gives the following: The work was done on a railroad, in one cut, the material being hauled two ways. In the cut there were 2,453 cu. yd., and 1,320 cu. yd. were hauled one way to an embankment, the average " lead " being 260 ft., making a run of about 620 ft. for a trip to the dump and back. A four-horse plow team with two men and a snatch team of two horses and a driver were used. Two men manipulated the bar and catch in loading the scrapers. One man did the dumping. The cost of this was: Foreman, 7% days at $3 $ 22.50 Scrapers, 38 days at $4.75 180.50 Plowing, 7% days at $9.20 69.00 Snatching, 7V 2 days at $4.75 35.62 Loading, 15 days at $1.60 24.00 Dumping 0.016 Water boy, 7% days at $1 7.50 Men, 2 days at $1.50 i . . 3.00 Total $353.37 The last two men were engaged in cutting down the slopes and dressing them. The cost per cubic yard for each item was as follows : Foreman $0.017 Scrapers 0.137 Plowing 0.052 Snatching 0.027 Loading 0.018 Dumping, 7% days at $1.50 11.25 Water boy 0.006 Sloping 0.002 Total per cu. yd $0.267 SCRAPERS AND GRADERS 289 Each scraper team traveled about 12 miles per day. The scrapers were Nos. 2i and held % cu. yd. place measurement. The average yardage moved per scraper-day was 34, while the average per team worked was 21. From the other end of the cut 1,133 cu. yd. were excavated, and moved an average distance of 400 ft. On the 260 ft. "lead" five scrapers were worked, but with the longer haul another scraper was added. As the embankment was across a marsh of very soft material, two men were needed on the dump to help dump and handle the material. More men were put at work on the slopes so as to have them done when the cut was finished. The cost of this end of the cut was: Foreman, 6 days at $3 $ 18.00 Scrapers, 38 days at $4.75 180.50 Plowing, 6 days at $9.20 55.20 Snatching 6 days at $4.75 28.50 Loading, 12 days at $1.60 19.20 Dumping, 12 days at $1.50 18.00 Water boy, 6 days at $1 6.00 Sloping, 30 days at $1.50 45.00 Total $370.40 The cost per cubic yard was as follows: Foreman $0.01S Scrapers 0.160 Plowing " 0.048 Snatching 0.025 Loading 0.017 Dumping 0.006 Water boy 0.005 Sloping 0.040 Total per cu. yd $0.327 Each scraper traveled 15 miles per day, and hauled 30 cu. yd,. The average moved per team worked was 20 cu. yd. For the entire cut of 2,453 cu. yd. the average cost was $0.295 per cu. yd. The average amount moved per scraper-day was 33.5 cu. yd. for an average " lead " of 325 ft. The Cost of Scraper Work in Freezing Weather is described in Engineering and Contracting, Feb. 12, 1908. This work was done during the early part of the winter before the heavy snows fell, and while the thermometer was below the freezing point during most of the day, and at night frequently registered as low as zero. The contractor had one scraper gang at work and was anxious to keep his teams going as late in the season as pos- sible, as he had a large amount of earthwork that would have to be done during the following summer. The following wages were paid for a 10-hr, day: 290 HANDBOOK OF EARTH EXCAVATION Foreman $3.00 Laborers 1.50 Teams, 1 driver, 2 horses 3.50 The material could be classed as " average earth " as a 2-horse railroad plow would loosen it, and keep enough ground plowed for the scraper gang. Owing to the ground freezing, 4 horses had to be used on the plow, and plowing had to be done both day and night, or else the ground became so hard it could not be broken up. Places that were not plowed continually did freeze so hard that work had to be abandoned there until the following spring. No. 3 Western wheelers with gates on them were used. The average " lead " was 250 ft., the material being carried in one direction only. Five scrapers were worked in the run, each scraper averaging 36 cu. yd. per day. As each scraper carried about % cu. yd., place measurement, this meant that the teams traveled about 9 miles per day. One man loaded the scraper, with the help of a 2-horse snatch team, the driver of this team hitching them to the scraper and unhitching them, as well as driving the team. The cost per cubic yard for the work was as follows: Foreman ' $0.017 Scrapers '. 0.097 Plowing 0.094 Loading 0.008 Snatching 0.019 Dumping 0.008 Extra men 0.016 Total per cu. yd $0.259 The two extra men were used to load the large frozen clods on top of the scraper, after it was loaded, and as it was about to pull away from behind the snatch team. One man stood at each side of the scraper, as it was being loaded with several large clods in his arms ready to throw them on, as the wheelers were loaded. If these clods became very plentiful at any particular place, these men would load several scrapers entirely with clods, by hand, and thus have them carried out of the cut. They did more of this work in the fore part of the day, as during the night a great many clods were made in the plowing. These men also kept up a wood fire at which the men could warm them- selves from time to time. The cost of plowing was high, as plowing was done with 4 horses both day and night, as previously stated. If this had not been necessary the plowing could have been done for less than 3 ct. per cu. yd. Of the total cost per cu. yd., at least 8 ct. can SCRAPERS AND GRADERS 291 be charged directly to the cohi weather, and 2 or 3 ct. of indirect charges can also be accounted for in the same way, as in good weather this scraper work only cost the contractor, including general expenses, 15 or 16 ct. per cu. yd. Cost of Wheeler Grading in Winter. Engineering and Con- tracting, Feb. 26, 1908, gives the following: In grading a railroad a section of a wagon road had to be built, and in order to carry on the railroad work the wagon road had to be graded during the winter months. The road was 2,800 ft. long and 30 ft. wide in the cuts, with a ditch on either side, 1 ft. deep, 1 ft. wide on the bottom, and 3 ft. across the top. The embankment was 26 ft. wide. There were 3,936 cu. yd. of excavation made from the cuts and borrow pits. The greatest depth of excavation was about 5 ft.; it averaged, in most places, about 3 ft. The work was commenced during the last week of January, when the weather was fairly good, and the lightest grading work was done before the worst weather set in. A 10-hr, day was worked, the following wages being paid: !:>> T)jt!fi;;.-ii Hoijtfiv if')j6i ;-;nyi;//' - fi \>\i\\\K\{ >.r:'/7 *L tt>1'irtXtyv> With the wages paid, and for scraper work in January, this was a reasonable cost. The cost of plowing was low, about half 292 HANDBOOK OP EARTH EXCAVATION of what it would have been had two plows been used, but one plow team did the loosening for the two gangs. Each scraper moved 26i cu. yd. per day. While this work was going on, a foreman and crew of men were laying some 12-in. terra cotta drain pipes across the roadbed. Three such pipes were laid, aggregating 123 lin. ft., the work in- cluding the ditches for them, as well as some small details to take the water to and away from them. The cost of this work was: Foreman, 1 day $ 2.50 Laborers, 14V 2 days 21.75 Total $24.25 This made a cost per lin. ft. of pipe of the following: Foreman $0.020 Laborers 0.175 Total $0.195 The work was finished during February, but for 10 days of the 17 worked it was bitter cold and light falls of snow occurred. The ground froze to the depth of a foot and the work was more expensive than that done in January. One scraper gang worked, the cost of it being as follows: Foreman, 16.8 days $ 50.40 Scrapers, 131.4 days 624.15 Plowing, 16.8 days 154.56 Snatch team, 16.8 days 100.80 Loaders, 33.6 days 53.76 Dumps, 33.6 days 50.40 Total $1,034.07 The yardage moved during this time was 2,539, the average " lead " being 350 ft. Each scraper moved about 19 cu. yd. per day. The cost per cu. yd. for each item was: Foreman $0.019 Scrapers 0.245 Plowing : 0.060 Snatching 0.021 Dumping 0.020 Total $0.405 In addition to this cost, the ground for a number of days had to be thawed, and two days of the coldest weather the teams could not work. Wood was used to thaw the ground, the wood being cut on the right of way, thus saving the price of stumpage to the contractor. It was hauled in dump wagons; each wagon hauled about y 2 a cord per load, and made four loads per day, making a total of 2 cords per wagon-day. A crew of men cut the wood SCRAPERS AND GRADERS 293 and loaded it on the wagons. Two men built the fires and main- tained them. In all about 28 cords of wood were used for t ne thawing. The fires were built in long windrows, and, as soon as the ground was somewhat thawed, the ashes of the fires were shoveled to one side, and a fire built up in another windrow. While this was burning up, a four-horse plow team with a pick pointed rooter plow, broke up the ground that had been thawed. This material broke up into clods which were hard to load into the scrapers. The plow point was broken frequently, and an extra one was kept in the tool box to replace it. After the foot of frost was loosened and excavated, the plowing was done by a heavy railroad plow. At night, before stopping work, the entire excavation was plowed over nearly a foot deep; this prevented the ground from freezing so solid during the night that the rooter plow could not loosen it the next morning. The cost of cutting and hauling the wood, and maintaining the fires was: n. J! j> -in t : u t \ ?;;-. Wagons, 14 days $66.50 Laborers, 21 days 31.50 Total . This cost must be added to the other. Distributed over the total yardage moved during the month this makes an additional cost of 3.8 ct., giving a total cost of 44.3 ct. per cu. yd. Natur- ally, the extra cost owing to the frozen ground is not covered by this one item of 3.8 ct., for a comparison of the February itemized cost with that of January shows a difference of 12.7 ct. The cost of plowing is more than double that of January, owing to a great extent to the fact that during February the plow loosened ground for the one gang of scrapers only, while during January it worked for two gangs. The haul in February had been increased by 50 ft. Of the total difference in cost at least 13 ct. can be directly charged to the cold weather and freezing ground. Of the ground actually thawed by the wood fires there were about 1,511 sq. yd. The cost of thawing this was about 6^ ct. per sq. yd. As the frost penetrated the ground about one foot this meant that 503 cu. yd. of earth had to be thawed, at a cost of 19 ct. per cu. yd. The material was a red sandy clay. Dur- ing the rest of the time, after the freeze, it was very muddy and difficult to handle. Fig. 11 shows a cross section of the road as it was actually built. The trimming and dressing outside of the ditches were done by a road machine immediately after the scrapers finished the work. Owing to the winter weather eight horses had to be 204. HANDBOOK OF EARTH EXCAVATION used on the machine, and this meant an extra driver. The mud made the work difficult. The most of this was $43.75 for 2i days' work. As the banks were 26 ft. wide, the total area dressed by the machine was 7,467 sq. yd., which gave a cost for trim- * Fig. 11. Cross Section of Road as Built. ming and dressing with the machine of 0.6 ct. per sq. yd. This cost distributed over the yardage moved, namely, 3,936 cu. yd., made 1.1 ct. per cu. yd. After the weather had settled in the spring and the ground had dried, a force of men under a foreman was put to work cutting the ditches in the cuts. The cost of this was: Foreman, 4 days $10.00 Laborers, 37 days 55.00 Total $65.50 From the ditches, 213 cu. yd. were excavated, which meant a cost of 30.7 ct. per. cu. yd., and as there were 3,075 lin. ft. of ditch 'the cost per lineal foot was 2.1 ct. Distributed over the total yardage excavated, it gave a cost of 1.7 ct., making the total cost of trimming and dressing per cu. yd. as follows: Work with road machine 1.1 ct. Work by hand 1.7 ct. Total per cu. yd 2.8 ct, This would also have increased the cost per sq. yd. more than 1 ct. If the cross section of the road had been as shown in Fig. 12, the road machine would have done all the dressing and trimming and the $65.50 could have been saved. This clearly demonstrates that the more economical design is that illustrated in Fig. 12. It must be remembered that the drainage can be amply cared for by the crown and the extra height of the metal. The road was given a metal coat, supposedly 6 in. thick, 16 ft. T^J^B^P^I Fig. 12. Cross Section of Road as It Should Have Been Built. SCRAPERS AND GRADERS 295 wide, of oyster shells. On account of the mud in. some places the shells were much thicker. These shells, 12,300 bushels, were delivered at a wharf near by on board of large scows, and were hauled in market wagons an average distance of 4,500 ft. The shells were loaded by scoop shovels, and the wagons had two holes cut in the bottoms. This allowed the shells to be dumped out of the end of the wagon and through the holes. One man with a large rake, a fork and a shovel spread the shells. The cost of this work was: Foreman, 5.8 days $ 14.50 Wagons, 45.3 days 215.17 Men loading, 17.4 days 26.10 Man spreading, 5.8 days 8.70 Total $264.47 This made a cost for hauling and spreading of 11.5 ct. per bushel. The shells were only put on about 2,300 lin. ft. of the road, giving about 4,100 sq. yd. The shells cost 7 ct. -per bushel delivered at the wharf. This gave a cost per sq. yd. of shells in place as follows: Shells 21 ct. Labor and hauling 11.5 ct. Total 32.5 ct. The shells were not rolled, but they were first placed on the road nearest the wharf, and the loaded and empty wagons hauled over them. As any holes developed, additional shells were placed in them. The total cost of the work was as follows: Scraper work $1,366.62 Labor of laying drain pipe 24.25 123 lin. ft. 12 in. T. C. pipe at 30 ct 36.90 Thawing ground 98.00 Road machine work 43.75 Ditching in cuts 65.50 12,300 bu. shells at 7 ct 861.00 Labor of placing shells 264.47 Total $2,760.49 All of this work could have been done cheaper if it had not been the dead of winter. Even the shells could have been bought for 4 or 5 ct. per bushel during the summer. Comparison of Cost of Wheel and Drag Scraper Work in Mis- sissippi. Cost data on the enlarging of a log pond are given by M. E. Allen in Engineering and Contracting, March 4, 190S. The work required the excavation of the end bank of an old pond and the extension of the side banks a distance of 350 ft. The area of the pond was increased from one to four acres. 296 HANDBOOK OF EARTH EXCAVATION As the site was full of pine, oak and gum stumps of consider- able size, and extremely difficult to dislodge except with dyna- mite, it was decided to raise the old banks 1 ft., giving a depth of 8 ft. where the logs are unloaded and a minimum depth of 3 ft. 6 in. in the far end of the pond over the 3-acre addition. In carrying out this plan it was decided that all stumps be sawed off at the ground, and that only enough dirt be excavated from the new pond site to build the banks, and that dirt be borrowed from the most advantageous places. The cross sections showed that the banks would require 2,028 cu. yd. It was estimated that by doing the excavation by com- pany's forces and teams the cost would not exceed $400. There were on hand four % cu. yd. wheel scrapers and two " slips." As there were 100 lin. ft. of bank so situated that dirt could be obtained right at hand and without plowing it was decided to let the slips handle the 162 cu. yd., and compare the costs for slips working under most favorable conditions and wheelers under average conditions. The two slips finished the 162 cu. yd. in 4.5 days, and, as the unit cost was found to exceed that of the wheelers under less favorable conditions, their use was discontinued. The total cost of all the grading with slips and with wheelers was as follows: Foreman, 17.5 days at $3 $ 52.50 Labor, 165.9 days at $1 165.90 Teams, 145 days at $0.77 111.65 Total $330.05 The cost per cu. yd. was 16.3 ct. The cost under teams includes only the actual cost of feed used, for the teams were all company property. The drivers are listed under labor. To arrive at a comparison for wheeler and slip work, 33% of the foreman's time was charged to the latter during the first 4.5 days that the slips were used. This gave a cost for the slip work as follows: 1 foreman, 4.5 days at (% of $3) $1 $ 4.50 4 men, 4.5 days at $1 18.00 2 teams, 4.5 days at 0.77 6.93 Total $29.43 This gave a cost per cu. yd. of 18.2 ct. The cost of the wheel scraper work alone was 16.1 ct. per cu. yd- The average number of cu. yd. handled per scraper-day was 29.6. The average lead was 150 ft. SCRAPERS AND GRADERS 297 Nine Examples of the Cost of Wheel Scraper Work. (See En- gineering and Contracting, July 8, 1908.) Some of these examples have already been given but their costs are repeated here for comparison. The cost records were kept in great detail. In every case the work done was in grading a railroad bed and No. 2^> wheelers were used. The wages paid for a 10-hr, day were as follows: Foreman $3.00 Scraper team and driver 4.75 4-horse plow team and 2 men 9.20 3-horse snatch team and 1 man 6.00 Loaders 1.60 Dump nun 1.50 Water boy 1.00 The grading was done in the fall of the year with good weather prevailing. The material excavated was red clay subsoil with some sand mixed with it. The teams were hired, the contractor furnishing the scrapers, plows, etc. Table 1 gives the length of the lead in feet, the lead being the distance in a straight line from the center of mass in the excavation to the center of mass of the embankment. The length of the haul exceeds the lead, the haul being the average distance traveled by the scraper in going to and from the dump, including the distance traveled in turning at both ends of the haul. A crew consisted of v a foreman, a 4-horse plow, a 3-horse snatch team, 2 loaders, 2 dump men, a water boy and the given number of wheeled scrapers. In Table 2 the cost of the work is given, showing the cost of each item separately. These costs do not include any allowance for plant or main- tenance and. repairs to plant. These records are not given either as ideal records or as eco- nomical examples of scraper work, but may be of benefit to those interested in scraper work. It would seem that the distance covered per day by each scraper in the first two examples was much less than it should have been, as in other examples each scraper team covered more than 16 miles. Under these circumstances, if the foreman did not allow his men and teams to loaf, time* must have been wasted by the scrapers in waiting to be loaded, thus showing that too many scrapers were worked in the run. This is evident for another reason. With a haul of 600 ft., with a team travel- ing at the rate of 200 ft. per min., which is not excessive even over such ground as a scraper is used upon, the scraper should make the round trip in 3 min. It takes not over a minute to 298 HANDBOOK OF EARTH EXCAVATION load a No. 2} wheeled scraper under fair conditions, hence from the time the scraper leaves the cut to its return only 3 scrapers have been loaded, with the result that the scraper must wait a minute while the fifth scraper is being loaded. From this it would seem that for a 260 ft. lead, 4 scrapers should be used instead of 5. This would have meant that the ex- penses of the gang would have been reduced $4.75 and each scraper worked would have moved a greater yardage. Theoretically the time wasted in waiting to be loaded would have allowed of 30 additional trips of a scraper during the day, which would have meant an increase of 10 cu. yd. per day per scraper. The in- crease might have been a little more, as the 5 scrapers set a lazy pace, while the 4 scrapers coming to the snatch team reg- ularly would have been the cue for the whole gang to have worked with greater snap and vim. This increased yardage would have meant that the gang would have averaged 176 cu. yd. per day, thus decreasing all the cost items somewhat. The time lost waiting to be loaded in using 5 scrapers on a 300 ft. lead, where the haul amounted to 725 ft., is not as much as on the 260 ft. lead, the lost time being but % of a min. The cut or excavation, instead of being worked as a single piece of work with a lead of 300 ft. and a haul of 725, should be divided into two pieces of work, so that one piece would have an in- creased haul over the 725 ft. and suited for a run of 5 scrapers, while the other piece would have a decreased haul, one suited to 4 scrapers. In this manner, the scrapers employed could be worked all the time, and the maximum output obtained and the "hauls equalized," as the contractors express it. From example No. 3 it would seem that 6 scrapers were about the correct number for a 1,000 ft. haul, but in example No. 4 the snatch team had to wait on the scrapers. This was likewise the case with examples Nos. 5 and 6. In example No. 7 too many scrapers were worked in the gang, and the contrast between the number used with an 800 ft. and 900 ft. lead is very striking. Again in examples Nos. 8 and 9 not enough scrapers were used. It will be noticed that for the shorter hauls the increased cost due to adding 100 ft. to the lead, with wages as paid for this work, is about 1 ct. per cu. yd. When the leads are longer than 500 or 600 ft. the costs increased much more than 1 ct. The ordinary price paid for overhaul in many sections of the country in the past has been 1 ct. per cu. yd. for each 100 ft. of overhaul. For short free haul with low wages there may be, at times, a small profit at this price, but under most circum- stances 1 ct. per cu. yd. per 100 ft. will hardly cover the cost of wheel scraper overhaul, especially if the free haul is 1,000 ft. SCRAPERS AND GRADERS 299 fc-r< ^ 5 o o o o o o o r-TccT o o o o o o C- tfD CO SO O CO tf3 ka X o O S O O O O O 3br ddo'dddd l 8 $ owcoco- d_d o o' d o < ^5 T-T "3 s fl O5 Oi ooo to t~-ooo g o d d d d d o i-H Tt< OO t- J W^ odd odd' W ^'^ us co t- ffi 5^5 300 HANDBOOK OF EARTH EXCAVATION Contractors should give this matter some study and see to it that their bids are such as net them a profit on each item. The writer knew of a contractor who bid an overhaul price of 2^ ct., with a free haul of 1,500 ft., and even at this price there was no profit in the overhaul during the winter months. The cost per cubic yard for plowing in Table 2 is high, when one takes into consideration that, at the wages paid, earth should be loosened for about 3 ct., but this high cost is caused by the fact that the plow team was kept in the cut during the whole day, whether it was working or not. According to the nine examples, the plow loosened on an average 160 cu. yd. per day. A 4-horse plow can easily loosen from 300 to 400 cu. yd. per day, say 350 cu. yd. This would mean considerably less than 3 ct. per cu. yd. This shows the necessity of working two scraper gangs, wherever possible, close enough together so that one plow team can serve the two gangs. Two men were used to load the scrapers. For a small wheel scraper, one man is sufficient, and it is possible for one man to load a No. 21 or No. 3 wheeler, but 2 men will do the work more efficiently, and they are needed when a 4-horse snatch team is used. Under most circumstances a 4-horse snatch team will do more economical work than a 3-horse snatch team. In the examples here given two men were used to dump the scrapers. This is not necessary, as one man can easily learn to dump even the large size wheelers without aid, and the only reason two men were used was on account of the labor market. Men were difficult to obtain, and to detail only one man to a dump meant a strike among the laborers. If only one man had been used the cost of dumping given would have been cut in half. It will be noticed that the cost of the items of the work, other than the actual scraper cost, amount to from 30 to 60% of the total cost, thus showing that the scraper must move from 50 to 100% more earth than needed to show a profit .on each scraper's work. Only the best horses or mules should be employed, and good care must be taken of them, or else they will soon grow stale in their work, and the output will rapidly decrease. Economic Handling of Earth by Wheei and Fresno Scrapers. Richard T. Dana in Engineering and Contracting, June 3, 1914, discusses this matter at great length. It has been the experience of the writer that a majority of contractors east of the Alleghenies are unfamiliar with the rela- tive advantages of the different kinds of scraper and do not pos- sess the data necessary to determine for the particular condi- tions of their work which style and size should be most eco- nomic. A contractor who has found wheel scrapers very success- SCRAPERS AND GRADERS 301 fc .8 W 02 S3 o'S a a a 'a - ;2^ f> H^- O >O r-t i 302 HANDBOOK OF EARTH EXCAVATION fill in a certain kind of earth is likely to be biased in favor of the wheel scraper for that kind of earth more or less regardless of the length of haul. Errors of judgment in a matter of this kind result in literally burying for all time money that ought to bring some benefit to somebody. A careful study and analysis of scraper work was made under the direction of the writer by A. C. Haskell for the Construction Service Co. of New York, and the results are given below to enable those who have scraper work to make rapidly and con- veniently those computations without which no work of this kind can economically be done. wo 200 300 400 500 600 700 Length of Haul in Feet $00 Fig. 13. Curves Showing Costs per Cubic Yard of Handling Loam and Loam Clay with Wheel Scrapers for Various Sizes of Load and Length of Haul. The results of this analysis are summarized in Figs. 13 to 15. When Fresno scrapers are loaded from plowed ground it is easier to load when dragging across than lengthwise of the fur- row. Double plowing is often economical. The dumping opera- tion should be accomplished by a quick, sharp lift on the handle, and preferably on a down grade. \Vhen the ground is very well loosened the driver can do his own loading as well as dumping. The path to the dump must be reasonably free from obstructions, else the scrapers may dump themselves without intention on the driver's part. SCRAPERS AND GRADERS 303 General Hints on all Scraper Work. (1) Be sure to use the right kind of scraper. A Fresno with 3 mules is economical up to about 275 ft. of haul as against wheel scrapers with 2 mules, when it can load readily. Where the ground is full of roots use wheelers. To drivers: (2) Report any case of bad fitting harness to the foreman im- 100 200 JOO 400 Length of Haul in Feet 500 Fig. 14. Curves Showing Cost per cu. yd. of Handling Loam, Sand, etc., with Fresno Scrapers for Various Sizes of Load and Length of Haul. mediately. Don't let the team drag you by the reins. You are supposed to lie able to walk as far as a loaded team. To foreman : Make a personal detailed inspection of each mule's harness the first thing in the morning and at noon, and report any case of ill fitting harness to the timekeeper on his next round. Fore- men will be held responsible for allowing any mule to work with bttcMv fitting harness. 304 HANDBOOK OF EARTH EXCAVATION (3) See that each scraper is fully loaded. The cost of plow- ing is less than 1 ct. per cu. yd., which is less than the cost of letting scrapers work when only partly loaded (4) In loading the scraper when it is once full of earth do not let the mules try to p. .11 it any farther and overload it. The last two seconds of drag against the dead weight of earth are mule killers. (5) On all scraper work drivers are required to walk at all times when the scraper is loaded and they are to walk at all times with the Fresno scraper, whether loaded or empty. With Wheeler's Loam-Wheelers Sand Fresno All Material Fresno -All Material I I I I I I I I 100 ^oo 300 400 500 600 l.cnqth of Houlin feet 00 Fig. 15. Diagram Comparing Economy Up to 275 Ft. Haul of Fresno and Wheel Scrapers. wheeler scraper work drivers should ride on the scraper when it is empty. In stepping on or off of the scraper be sure not to delay the team in any way. (6) In dumping wheel scrapers try not to dump when the mules are on ground that is lower than the scraper, as by doing this it brings a tremendous load on the mules' necks. (7) So direct the work that the loaded teams will have the shortest haul and the empty teams if necessary may have a much longer haul, but in no case should the empty haul be un- necessarily long. It is better to let the mule team stand still to rest than to let it cover unnecessary ground. This seems SCRAPERS AND GRADERS 305 like a simple rule, but its violation has often been observed on several different jobs. (8) See that the scrapers are spaced as even a distance apart as possible. This will make the work lighter on the mules, easier on the drivers and Mail tend to avoid confusion. (9) The loaded scraper should always have the right of way as against the unloaded scraper. (10) Whenever a scraper gets stuck or is in any trouble don't lose any time before notifying the foreman and sending for help. The snatch team is employed for the purpose of helping the scrapers at all times and in all possible ways. (11) Be sure not to have too few scrapers on a long haul and too many scrapers on a short haul; see that every scraper is busy all the time; see that the loader and snatch teams are busy all the time; in short, that each unit of the work is con- tributing its maximum effort to the accomplishment of the whole. Costly Wheel Scraper Work in a Wet Cut. Engineering and Contracting, Sept. 30, 1 ( J08, gives the following: The record of cost of making a railroad cut with wheel scrapers, given below, demonstrates how a lesson can be learned from cost keeping. The material in the cut was a red clay with springs of water occurring in it. This, with the fact that the clay quickly absorbed the rain water and held it, made the cut a wet one. Wheel scrapers were used and a 3-horse snatch team for loading them. A 4-horse plow team loosened the dirt. The following wages were paid for a 10-hr, day: Foreman $3.00 Scraper team and driver 4.75 4-horse plow team and 2 men 9.20 3-horse snatch team and 1 man 6.00 Loaders 1 60 Dumpmen 1 50 Water boy 1.00 Two men loaded the No. 2^ scrapers, and one man dumped them. The lead was 700 ft., while the total distance traveled to and from the dump averaged 1,650 ft. The cost of the work per cu. yd. was as follows: Foreman $0.063 Scraptrs 0.500 Plowing 0.200 Snatching 0.127 Loading 0.067 Dumping 0.032 Water boy 0.021 Total per cu. yd $1.010 306 HANDBOOK OF EARTH EXCAVATION The average number of cu. yd. moved per day per scraper was 9.5, and as 10 scrapers were used on the haul, the gang moved a total yardage per day of 95 cu. yd. This gives the amount loosened by the plow. The average number of yards moved per team worked in a day was only 5.5. Each scraper team traveled about 9 miles per day. A comparison of these with costs previously given shows at once that they are excessive. The scraper team traveled only 9 miles per day. This was caused by the wet condition of the cut, and ten scrapers each going through it 28 or 29 times a day meant cutting up the wet clay still more. Some other method of excavating the earth should have been used. Doubletrees for Heavy Slip and Fresno Scraper Work. R. E. Post, in Engineering and Contracting, Mar. 6, 1912, gives the following: In moving dirt with slips or fresnos and the accompanying work of pulling roots, dragging large rocks, etc., one of the most annoying delays is caused by the use of weak or clumsy double- tree sets. One of the worst details is the singletree hook which pulls from the back of the singletree and which, whenever the double- trees are used off of a tongue, cause the singletree to turn half over. Usually at the first hard pull the cast eye of the single- tree ferrule breaks, or the center clip spreads. Then there is the device and bolt method of fastening the doubletree set to the slip. This is a good rig (although necessitating heavy doubletrees), so long as the team is on a slip, but when needed elsewhere some time is wasted unfastening and fastening the device. Moreover, the device is a poor device to which to fasten a chain or rope quickly and when a doubletree set is not in use someone usually takes the device and forgets to return it. The above annoyances are likely to occur many times a day where such doubletree sets are used and they provoke foremen and teamsters as well as cause considerable delay. The factory-made doubletree sets sold under the name of lead bars are light and handy, but will not stand use on a plow, stump pulling, or other heavy work without much breakage. Further the center clip, fastening the hook to the doubletree, soon becomes loose and pulls to one end. Home-made double- tree sets made of the best woods with factory-made center clips, end straps, and hooks, are a great improvement over the lead bars, but the largest oval woods obtainable for the doubletrees will not stand all kinds of work without considerable breakage and the center step fastening the hook to the doubletree behaves the same as in the factory-made lead bars. SCRAPERS AND GRADERS 307 Fig. 16 shows a set of doubletrees that will stand the jerks of the heaviest teams, that is not too heavy, that is reasonable in cost, and that will not ordinarily be in the repair shop until worn out. The doubletree center clip in particular is a trouble saver, as whenever the wood shrinks and the clip becomes loose it can be readily tightened with the bolt. Another advantage <,........ .-j5 - ^ .*" {.Steel HooK\ ! i'lhon^W** 2 * ^vct) f" *T-^&\-'\& fl-'V-""7;r^t^-^^y * lj*W)Nood-' * -30 * - , - ,.. [ng.VContg Section ofDovblcTrcceiipWooH Fig. 16. Detail Drawing for Slip Doubletrees. is in being able to replace a broken hook without a weld. In case considerable work involving pulling on a chain is to be done a special grab hook may easily be inserted or, better yet, one or two sets can be rigged with grab hooks and kept for this work. The following is the itemized cost of one of these doubletree sets: 4 ft. 1-in. half round iron $0.135 7 ft. %-in. half round iron 0.130 1 3% x 36 in. wood 0.420 2 2% x 36 in. wood 0.400 1 ft. %-in. tool steel 0.110 4 singletree hooks 0.160 16 in. %xl% in. iron 0.085 2 center clips 0.240 12 rivets 0.050 1 bolt %x2 ins 0.015 2% hr. labor at 45 ct 1.125 Total $2.870 Methods of Arranging Doubletrees and Three-Horse Eveners. Engineering and Contracting, June 12, 1912, gives the following: In making three-horse eveners little difficulty will be experi- enced if consideration is taken of the fact that the amount of work each horse does is in proportion to the lever arm or the portion of the doubletree given to him. In the case of three horses the third horse, or the one which works singly, should be given a leverage to make its pull equal to that of the other two. 308 HANDBOOK OF EARTH EXCAVATION The length of the evener, and also the lengths of the single- trees, will depend upon the size of the horses and also whether it is desired to work them close together or somewhat spread apart. For summer work the horses will stand the heat better if given plenty of room. In Fig. 17 is shown a common three-horse evener arranged for horses of about equal weight and strength. The distances shown Fig. 17. Common Three-Horse Evener. are recommended for horses of medium size and should be in- creased proportionately for large teams. Sometimes it is necessary in working young animals or light horses to give them plenty of advantage by increasing the length of the lever arm. This must be done by trial, as no rule will do for all cases. The most satisfactory way is to bore a number of holes and shift the clevis until the small horse is able to carry the load the entire day without becoming more fatigued than the other horses. Tt is believed by some men that the amount of lever arm or advantages given to the smaller horse should be in proportion to the weight of the animal, but this is not al- ways satisfactory because it is also necessary to take into account the physical condition of the horses. A type of evener which per- mits an unusually close hitch is shown by Fig. 18. These two U 28 J Fig. 18. Evener for Close Hitching. eveners are recommended in the Bulletin of the International Harvester Co. Effect of Bonus System on Cost of Basement Excavation. En- gineering and Contracting, July 22, 1914, gives the following: It is unquestionably true that most workmen will put forth extra effort when they are certain of receiving monetary return for extra performance. The following data show the results of a bonus system as applied by the Aberthaw Construction Co., of Boston, to excavation work. The work consisted of excavating the SCRAPERS AND GRADERS 309 site of a reinforced concrete building in New Haven, Conn. The building was 62 ft. wide by 400 ft long, the basement floor being about 10 ft. below the natural grade. The work was done in mid-winter. As the excavated material was to be used in bringing up to grade the depressions in other parts of the lot, the contractors decided to use wheel scrapers. In addition to .the excavated earth, quantities of sand were taken out and placed in storage piles for use later in concrete. The loam and top soil were first removed by means of plows and frost wedges. A study of the length of haul and of the number of wheel scraper loads per day showed that on the average 120 loads con- stituted a full clay's work, although for the longer hauls only about 110 loads per day were made. The teamsters, when going about their work in the usual leisurely way and with no incentive for high performance, at best were hauling only 120 to 130 loads per day. The application of the bonus system changed the entire tone of the work from half-hearted endeavor to enthu- siastic effort. In starting payment for extra work each driver who had made 120 loads or more during the day was given a bonus of 50 ct. This bonus was later increased to $1 for each man who made 150 loads during the day a mark which several reached. It was expressly stipulated that the horses should not be mistreated and that loads which were not full would not be credited on the tally board. While these instructions were well followed, it is prob- able that the horses were worked to their limit. The curves of Fig 19 show the variation in quantity of excava- Fig. 19. Curves Showing Variation in Quantity of Excavation, Bonus Paid, and Unit Cost for Basement Excavation in New Haven, Conn. 310 HANDBOOK OF EARTH EXCAVATION tion, amount of bonus paid, and cost per cubic yard for excavation. No attempt has been made to give actual values as comparative values only were desired. By referring to these curves it is seen that the cost per cubic yard of excavation was lowest when the quantity of excavation and consequently the amount of bonus were highest. It will be noted that increase or decrease in cost per cubic yard of excavation is in inverse ratio to the in- crease or decrease of quantity of excavation and bonus paid^ throughout the length of the curves. The decrease in cost from about 35 ct. per cu. yd. at the time the bonus was first applied to 25 ct. per cu. yd. and under for the peak of the excavation curve involved a saving of more than $60 per day during the period of maximum excavation. Keeping Cost of Scraper Work so as to Show the Daily Unit Cost for Each Gang is described by W. A. Gillette in Engineering and Contracting, July 24, 1912: The value of daily cost records is widely recognized but unless earth is handled in wagons or cars the difficulty of estimating quantities is such that daily records are seldom kept. FRESNO EXCAVATION DAILY REPORT Date Job No Gang No. Foreman Occupation No. Rate Amt. Sub-foreman 1 $3.10 $3.10 Fresno stock 4-up 36 1.00 36.00 Fresno drivers 9 2.00 18.00 Fresno loaders 2 2.00 4.00 Fresno dumpers 2 2.00 4.00 Plow stock 6-up 6 1.00 6.00 Plow stock up .... Plow stock up Pile drivers 1 2.25 2.25 Plow holders ,. 1 2.00 2.00 Laborers 1 2.00 2.00 % overhead cost 29 .... 14.40 Men 17 $91.75 Totals Stock 42 Sta. under construction Sta. completed Cu. yd. moved, 280. Cost, 32.7 ct. cu. yd. Length of haul 300ft. Kind of dirt Sand and gravel Remarks Timekeeper. Fig. 20. Timekeeper's Report Form for Fresno Excavation. SCRAPERS AND GRADERS 311 Mr. Gillette's method of keeping cost consisted in having the timekeeper count the loads hauled by every gang during at least two 20-min. periods, one in the forenoon and one in the after- noon. The timekeeper is provided with a saddle horse. The timekeeper was given a statement of the estimated size of load of each kind of scraper and wagon. Thus, a No. 2^ wheeler was estimated to hold % cu. yd., measured in place. A " three-up " dump wagon was estimated to average 1% cu. yd. GRADER EXCAVATION DAILY REPORT Date Job No Gang No. Foreman Occupation No. Rate Amt. Sub-foreman Excavator stock 16-up 16 $1.00 $16.00 Lead drivers 1 3.00 3.00 Push drivers 1 2.50 2.50 Machine men 1 4.00 4.00 Elevator men 1 2.50 2.50 Wagon stock 3-up 15 1.00 15.00 Dump men 1 2.50 2.50 % overhead cost 18 8.70 Men 5 .... $59.20 Totals Stock 31 Sta. under construction ; Sta. completed Cu. yd. moved, 595. Cost, 10 ct. cu. yd. Length of haul 300ft. Kind of dirt Sand and gravel Remarks Timekeeper. Fig. 21. Timekeeper's Report Form for Grader Excavation. Fresnos were estimated at different capacities, according as the pull was uphill, or downhill, or level; and in some cases it mi^ht be desirable to vary the estimate, according as the haul is short or long. The first month this plan was tried about 70,000 cu. yd. were moved and the timekeeper's estimates came out only 5% in excess of the engineer. The second month, for an equal amount of work, he was nearly 5% too low, so that for a period of two months the engineer's estimates were checked almost exactly. By following this plan it was soon discovered that wheeler work was costing more than fresno work. Also that for hauls 312 HANDBOOK OF EARTH EXCAVATION of more than 150 ft. the cheapest method was to load wagons with fresnos through a trap. This plan of intermittently timing each grading gang has the great merit of enabling the contractor to ascertain approximately his unit cost every day for every gang. TRAP EXCAVATION DAILY REPORT Date Job No Gang No. Foreman * Occupation No. Rate Amt. Sub-foreman 1 $2.50 $ 2.50 Fresno stock 4-up 20 1.00 20.00 Fresno drivers 5 2.00 10.00 Fresno loaders 2 2.00 4.00 Fresno dumpers 1 2.00 2.00 Wagon stock 3-up 15 1.00 15.00 Wagon drivers 5 2.00 10.00 Plow stock 2-up 2 1.00 2.00 Plow stock up Trap men Dump men 1 2.50 2.50 Plow drivers 1 2.25 2.25 Plow holders % overhead cost 25 12.45 Men 16 .... $82.70 Totals Stock 37 Sta. under construction Sta. completed Cu. yd. moved 730. Cost, 11.3 ct. cu. yd. Length of haul 300ft. Kind of dirt Sand and gravel Remarks Timekeeper. Fig. 22. Timekeeper's Report Form for Wagons Loaded by Fresnos Through a Trap. A Four- Wheel Scraper of Large Capacity. Engineering News, Oct. 21, 1915, gives the following: Recently a four-wheeled scraper of 1 cu. yd. capacity has been introduced, and has been used with success in a number of con- struction works. (See Figs. 26 and 27.) A steel frame is carried by two axles, having 30-in. front wheels and 48-in. rear wheels, and its forward end is arched so as to clear the wheels and allow the machine to make a very short turn. The steel scraper bucket is 46 in. long, 45 in. wide and 25 in. deep, with a nominal capacity of 1 yd., but heavier loads SCRAPERS AND GRADERS 313 have been excavated and hauled. , The rear end of the bucket is suspended by short chains attached to the sills of the frame and to the bottom corners of the bucket. The front end of the bucket has a bail pivoted to the bottom corners, with chains passing over a shaft carried above the frame. This shaft is fitted with sprocket wheels driven by chains from the axle, a clutch enabling the shaft to be thrown in or out of gear. The driver sits at the rear, where he has a good view of the work. WHEELER EXCAVATION DAILY REPORT Date Job No ..................... Gang No Foreman Occupation No. Rate Amt. Sub-foreman .................. 1 $3.10 $3.10 .Wheeler stock 2-up ........... 20 1.00 20.00 Wheeler drivers .............. 10 2.00 20.00 Wheeler. loaders ............... 4 2.50 10.00 Wheeler dumpers ............. 2 2.50 5.00 Snap teams 3-up .............. 6 1.00 6.00 Snap drivers .................. 2 2.50 5.00 Plow stock 4-up .............. 4 1.00 4.00 Plow stock up ................ ---- ...... Plow stock up ................ .... ...... Plow drivers ................. 1 2.00 2.00 Plow holders .................. 1 2.00 2.00 % overhead cost 28 . . . . ......... .... 13.90 Men ........... 21 .... $91.00 Totals ...... Stock .. ....... 30 ---- Sta. under construction ................................. Sta. completed .......................................... Cu. yd. moved, 378. Cost, 24 ct. cu. yd. Length of haul ................................... 300ft. Kind of dirt ........................... Sand and gravel Remarks ........................... ..................... Timekeeper. Fig. 23. Timekeeper's Report Form for Wheeler Excavation. He handles the levers for controlling the movements of the bucket, in loading, dumping and spreading, and p no extra men are required at the scraper in loading or dumping. In loading, the forward end of the bucket is lowered and in- clined forward, so that its cutting edge touches the ground. An end gate at the rear retains the material. When loaded, the front end is raised by the chains on the shaft so as to bring the bucket to a practically level position, when it has plenty of clear- ance for hauling. An automatic trip releases the clutch v/hen 314 HANDBOOK OF EARTH EXCAVATION the scraper is in this position, thus preventing accidental over- winding of the chains and dumping of the load. For dumping, the chains are wound up still farther so as to raise the front end and tilt the bucket backwards, falling clear of the end gate. The load may be dumped in a heap at one spot, or spread in a thin layer, according to the inclination given to the bucket. The operations are shown in Figs 26 and 27, which show the loading and dumping respectively. The front and rear wheels do not SUMMARY OF DAILY COSTS Date . . . Job No.. Foreman Area Cu. yd. Cost Total Method of Constr. cov. moved per amt. Fresno excavation Fresno excavation Fresno excavation Wheeler excavation Wheeler excavation Wheeler excavation Grader Grader Grader Trap excavation Trap excavation Trap excavation Rollers Rollers Oil wagons Oil wagons Brushing Totals . Average length of haul Average cost per Average cost per Remarks Timekeeper. Fig. 24. Form for Summary of Daily Cost. track. This feature (in combination with wide tires and the weight of the machine) reduces the tendency to wear ruts, and is efficient in rolling and compacting the material, as in embank- ment work. From two to four horses (or mules) haul the machine, accord- ing to the character of the work, but in loading an extra four- horse snap team is generally used. Hard ground must be plowed to enable the horses to do efficient work in loading, but this is not necessary when traction engines are used, as has been SCRAPERS AND GRADERS 315 clone in several cases. Engines of 12 to 16 hp. have been used for loading, and sometimes they are used also for hauling, the engine taking a train of two to six scrapers. The cost of loading is estimated to average 4 ct. per cu. yd. in ordinary material. The cost of hauling varies with the grade and condition of road, etc., and ranges from % ct. to 1 ct. per cu. yd. for each 100 ft. of haul up to 1,000 ft. Working in a hard and heavy brick clay at St. Louis, a 16-hp. traction engine was OVERHEAD COSTS DAILY REPORT Date Job No Foreman Occupation No. Rate Amt. Superintendents 1 $5.75 $ 5.75 Timekeepers 1 2.75 2.75 Blacksmiths 1 4.00 4.00 Blacksmiths' helpers 2 2.00 4.00 Stablemen 1 2.40 2.40 Stablemen's helpers 2 2.40 4.80 Water boys 1 1.75 1.75 Camp laborers 2 2.00 4.00 Camp Camp Camp stock working 6 1.00 6.00 Camp stock drivers 2 2.00 '4.00 Camp stock .... Stock idle 1 1.00 1.00 Driving stock Riding stock 2 1.00 2.00 Sick or idle men 1 2.00 2.00 Sub-foreman brushing 1 3.00 3.00 Men brushing 5 2.00 10.00 Men 20 .... $49.45 Totals Stock 9 Remarks Timekeeper. Fig. 25. Form for Summary for Overhead Costs. used for loading, and three horses to each scraper for hauling. The loading averaged 1^4 min., or 48 loads per hr., with an aver- age of 29 cu. ft. to each load. The machines huve been used on railway and reservoir embankments in California; in the latter case the borrow pits were small and scattered, and the haul varied from 200 ft. to 1,500 ft. Their work on the South Branch Canal of the Klamath irrigation project in Oregon (U. S. Re- clamation Service) is reported as follows by the contractors, Wells Brothers, of St. Louis. 316 HANDBOOK OF EARTH EXCAVATION " From original surface of ground to top of dyke averaged about 14 ft. The canal was built in the embankment and the Fig. 26. Maney Four- Wheeled Scraper with Pan in Position for Loading. Fig. 27. Maney Four-Wheeled Scraper with Pan Raised for Carrying Load. vi?*.;; Mi!f :fi ;j:i>n>s'!r! rrpjin/T- bottom of the finished canal was 8 ft. above the original surface of the ground. The entire embankment went up in 6-in. lifts, each lift being sprinkled. The specifications called for each lift being SCRAPERS AND GRADERS 317 rolled with a grooved roller weighing 1 ton per ft. of tread, but the Government engineers and inspectors ordered us to take the roller off, as the wheel-scrapers answered to better advantage owing to the front wheels having a narrower tread than the rear ones, and the wheels packing the material better than the roller would have done. The wheels would pack it in low places where the roller would have run over without touching. " The average haul was 400 ft. from borrow pit to dyke. After 18 in. were removed from the borrow pit, hardpan was en- countered requiring eight and ten head to plow. This latter ma- terial was handled to the depth of the pit, which was 5 ft. This material could not have been handled at all with grader and wagons, nor with ordinary wheeled-scrapers with profit. The 170,000 cu. yd. handled cost 14 ct. per yd., including the cost of moving to and from the work, which amounted to about $2,000." These four-wheel scrapers have been used in street and road work, for levees and ditches, railway embankments, canal exca- vation, and miscellaneous light and heavy grading and filling. On one job 50,000 cu. yd. of loamy soil were removed from ridges and deposited in a pond of water, with an average haul of 200 ft. The cost of this work is said to have been only 10 ct. per cu. yd. In New York, the machines have been used for remov- ing snow, loading it from the winrows formed by plows. Methods and Cost of Excavating a Canal with Four-Wheel Scrapers. Engineering and Contracting, May 31, 1911, gives the following: At Los Animas, Colorado, an irrigation canal, 50 ft. wide and deep enough to carry about 5 ft. of water, is being excavated with Maney four-wheel scrapers (Figs 26 and 27). The canal fol- lows the contour of a rather broad and level basin and the ma- terial is a hard adobe clay. The scrapers were at first loaded with a snatch team and later with a traction engine and cable. The latter method made a reduction in the operating costs of about 1 ct. per cu. yd. The cost of the team outfit was as follows : 4 Maney scrapers at $260 $1,040 12 animals, including 4 on snatch team 3,000 T tai ..::....:;:;..,.... .:; : ... $4,040 Cost of operation with snatch team: 12 animals, feeding per day $ 9.00 4 men on machines at $2 8.00 1 pit man 2.50 1 dump man 2.50 1 snap man 2.50 Total . . $24.50 318 HANDBOOK OF EARTH EXCAVATION With this outfit and an average " lead " of 250 ft., 600 loads of 1 cu. yd. each were made per day of 10-hr., costing about 6 ct. per cu. yd. The use of the traction engine brought the cost of the outfit up to $5,040, but the output was increased considerably. The traction engine remained stationary in loading the scrapers. A horse was used to drag the cable from the engine to the farthest point for loading the scrapers and the cable was then wound in on the drum of the engine as each scraper load was taken. The cost of operation with the engine in place of the snatch team was as follows: 4 men on machines at $2 $ 8.00 8 animals (feed per team per day), at $1.50 6.00 1 pit man 2.50 1 dump man 2.50 1 snap man 2.50 1 cable man 2.00 1 engineer 3.00 1 clutch man 2.00 Coal 5.00 Haul of water 2.00 , Total daily expense $35.50 With this method about 1,000 loads per 10-hr, day were averaged on a 250 ft. haul, or at a cost of about 5 ct. per cu. yd. The scraper itself differs from the ordinary scraper not only in the number of wheels but in that the scoop is tilted backward when unloading. The mechanism can be entirely in control of the driver, who operates the levers from his seat in the rear of the machine. By means of these levers he controls the sprocket chains that mesh into the sprocket wheels on the rear axle. The movement of the team therefore dumps the load. The capacity of the scraper is 31 cu. ft. This "self-loading wagon" is made by The Baker Mfg. Co., 506 Stanford Ave., Springfield, 111. Cost with 4-Wheel Scrapers on Road Work. Prof. A. B. McDaniel in Engineering Record, July 31, 1915, gives the cost of operating Maney four-wheel scrapers on road construction. In several cases, with soils varying from dry sand to hard, dense clay, it has proved its adaptability and efficiency. In loam and clay soil, with occasional sand and fills of ash and cinders, in Illinois, the cost of operation was 8 ct. per cu. yd with an aver- age haul of 300 ft. on nearly level ground. The width of cut averaged 20 ft., and the depth of cut was from to 18 in., aver- aging 12 in. Each scraper was hauled by a two-horse team and assisted in loading by a traction engine. The length of working day was 10 hr. The cost was as follows, when each of 7 scrapers averaged 114 cu. yd. per day: SCRAPERS AND GRADERS 319 Labor : 2 firemen, at $3 $ 6.00 1 cableman 2.00 7 teams and drivers, at $5 35.00 Total labor per 10-hr, day : $43.00 1 traction engine and operator $16.00 General and Overhead Expenses: Supervision and general expenses $3.00 Interest on investment (7% of $1,800) 0.62 Depreciation, based on 5-yr. life 0.88 Repairs, estimated 1.00 Total general and overhead expenses $ 5.50 Total cost of work per day $64.50 Total amount of excavation, 800 cu. yd. Cost per cu. yd. excavated $0.08 Maney Four-Wheel Scraper on Street Work. Municipal En- gneering, Sept., 1915, describes the use of the Maney four-wheeled scraper as follows: On a 23,500 sq. yd. vitrified brick pavement job at Pekin, 111., six Maney four-wheel scrapers were used in the grading of approx- imately 12,000 cu. yd. These scrapers were loaded by tractor, making a round trip of 1,200 ft. in approximately 14 min., or forty-three round trips per 10-h. day; 43 cu. yd. per scraper, totalling 258 cu. yd. per 10-hr, day. The force engaged in the grading work consisted of seventeen men, six of whom were driving the scrapers, one running the tractor, two trimming up the edges of the cut near the scrapers, three making curb ex- cavations ahead of the scrapers and live men on the dump. The dump is at the edge of the river bank. To reach it from the point at which the scrapers were working it was necessary to haul nearly two blocks over the unimproved street, then to wind around a temporary road, cross several railroad tracks and then skirt the top of the bank to the dump. .It was necessary for some of the scrapers to go part way down the bank to dump; others dumped along the top, and the men on the dump trimmed the material up. In returning to the loading point the scrapers took a slightly longer route to avoid interfering with the loaded scrapers moving toward the dump. Engineering and Contracting, July 3, 1918, reports the use of a 4-wheeled scraper hauled by a small tractor on street and side- walk grading near Dayton, O. The first use of this method was on a short haul of 80 or 90 ft. Only two men were used on this part of the work the tractor operator and the scraper operator. The Maney scraper, being self-loading and self -dumping and carrying about 1 cu. yd. of dirt to the load, was easily handled in this manner. On this work no plowing was necessary, as the direct power of the tractor was used for digging, loading and 320 HANDBOOK OF EARTH EXCAVATION hauling. A round trip was usually made in about 2 min. or at the rate of about 30 cu. yd. an hr. The cost of operating was stated to be 80 ct. per hr., making the cost per cu. yd. about 2% ct. Fig. 28. The Aurora Reversible Road Machine Made by the Austin Western Road Machinery Co. The tractor and Maney scraper were also used in the same manner for the rough excavating for sidewalks. The cutting was made to within an inch or so of grade and eliminated con- siderable hand work. Koad Graders. Some makes of road grading machines are pro- Fig. 29. Western Midget Light Weight 2-Horse Grader. Suit- able for Road Maintenance. Made by the Austin Western Mfg. Co. :iI 5 r < -I..J 1 T>'tVl"! SCRAPERS AND GRADERS 321 vided with attachments for shifting the frame back and forth on the rear axle, so as to adjust the blade to a desired position with reference to the wheel tracks, also with devices to lean the wheels at' an angle and thus lessen the tendency of the machine Fig. 30. The 20th Century Farm Ditcher. to slide over a bank, or to cut the rear wheels at an angle with the frame in order to overcome the tendency to slide when the blade is loaded. Most of the better makes of such machines are now constructed so the blade may be reversed entirely and the convex surface used for smoothing a road after it has been Fig. 31. Special Fender Attachment for Converting Ditcher into a Bottomless Scraper-. graded approximately to the required cross-section. Machines of this type are made in different sizes and weights and cost from $175 to $300 f. o. b. factory in 1914. The heavier sizes are best adapted to 'construction work and the lighter for maintenance. 322 HANDBOOK OF EARTH EXCAVATION A modified form of grading machine consists of a blade similar to that of the machine just described, which is supported by a simple frame on only two wheels. The 2-wheeled machine usu- ally weighs about one-fourth as much as the 4-wheel type and costs considerably less. A modification of the road grader useful for both grading and ditching is made by the Baker Mfg. Co. of Springfield, 111. This machine, as illustrated in Fig. 30, is provided with a moldboard 6 ft. long by 13 in. wide with a 5-in. detachable cutting blade. It weighs complete 800 Ib. The machine may be used either with or without the front truck. Attachments are made for cutting sage brush and for converting the ditcher into a bottomless scraper. (See Fig. 31.) Fig. 32. The Martin Ditcher and Grader. Another Hype of scraper ditcher, made by the Owensboro Ditcher and Grader Co., Owensboro, Ky., is illustrated in Fig. 32. Smoothing Machines suitable for leveling and maintaining roads but not for grading are made in various forms. Fig. 33 shows a machine that will level the entire surface of a 30-ft. road. It is designed to be pulled by a tractor of from 15 to 25 -hp. A much simpler machine for the same purpose is the two-blade road drag weighing 290 Ib., Fig. 34. Its two 8-ft. blades are each 6 in. wide and are set 3 ft. apart. A similar 3-blade road drag weighs 370 Ib. and is 45 in. wide. Grading Methods and Costs on Earth Road Construction. SCRAPERS AND GRADE&S 323 Charles H. Moorefield, in Engineering and Contracting, Apr. 18, 1917, gives the following: Where the grade and cross section of the road follow closely the original ground surface, most of the necessary grading usu- Fig. 33. "Uncle Jim," Self-Operating Road Leveler. Made by the Baker Mfg. Co. ally may be done with the grading machine. A 4-wheel machine should be used with at least six horses. The team must be ac- customed to working together and must be under complete control of the driver. Fig. 34. Prairie 2-Blade Road Drag. Made by Baker Mfg. Co. Before any machine work is done the area to be graded should be burned or mowed over so as to remove all grass and weeds. The grading should then proceed as follows: 324 HANDBOOK OF EARTH EXCAVATION (1) Set a row of stakes 100 or 200 ft. apart along the inside edge of each side ditch. The purpose of these stakes is simply to aid the driver in making the initial furrow of the machine conform with the line of the road, and since the stakes are destroyed by the first furrow they need be only sufficient to serve this temporary purpose. (2) Set the blade of the grading machine at an angle of about 30 degrees with the road, so that the material loosened by the cutting point of the blade will be moved in toward the center of the road; also lower the cutting point and raise the heel, so that the blade will plow an initial furrow about in. deep and about 18 in. wide. Then make the initial trip with the point of the blade cutting about 18 in. outside of the stake line and the outside rear wheel of the machine against the face of the furrow. The material loosened by the first furrow then will escape under .the blade in a ridge just inside the stake line. (3) Readjust the machine so that when the outside horses follow the initial furrow in making the second trip the blade will cut a new furrow of somewhat less width than the first and the outside rear wheel will follow the face of the new furrow. Then make successive trips with the machine adjusted in this way until the outside edge of the ditch is approached, except that after each two trips it is well to rest the team by readjusting the blade and pushing the loosened material over toward the center of the road. For this latter work the blade may be set at a greater angle with the road, and the heel should be lowered and the point raised, so that the cutting edge will conform closely to the crown of the road while the machine is in operation. (4) Repeat the above described operation, omitting the stakes and beginning about 18 in. farther from the center each time, until the side ditches are excavated to the required depth and the road is approximately to the required cross section. (5) Bring the outside faces of the side ditches to a uniform slope by making one or two trips of the machine with two wheels, one front and one rear, on the bank and the cutting edge of the blade against the slope. (6) Make several trips over the road, cleaning out the ditches and smoothing up the surfaces. The last few trips should be made with the blade reversed, as this method tends to produce a better compacted surface. But, in any event, it is necessary that during the first few months after the grading is completed the road surface should be kept smooth while it is being com- SCRAPERS AND GRADERS 325 pacted under traffic. To do this may require frequent use of the grading machine or the drag. The method of operating a grading machine described above necessarily will have to be modified at times in order to meet special conditions. Where, for example, the ditch area is cov- ered with heavy sod or contains a number of large roots, it may be very desirable to plow this area and cut the roots with an ax before using the grading machine. If this is done the plow furrows should be turned toward the center of the road and the line of the initial furrows should be controlled by two rows of stakes as described above. If the sod is very tenacious it should be harrowed with a disc harrow ahead of the grading machine, and after the material has been moved over toward the center of the road the lumps of sod should be thrown out. A method sometimes followed is to skim off the sod, by means of hand shovels, ahead of. the grading machine, but this method is expensive and seldom justified. Whether or not it is necessary to contend with any consider- able quantity of sod, the use of a disk harrow usually will prove helpful in securing a smooth uniform road surface with the grading machine. In general it is sufficient to give the loosened material a thorough harrowing after the road has been brought approximately to its required shape, but before the final shaping is done. Where continuous long stretches of road are to be graded with grading machines, it frequently is economical to substitute a traction engine for the teams and to employ two machines. Where this is done the first machine is connected immediately behind the tractor, either directly behind or to one side, as the conditions require, and the second machine is connected behind and to one side of the first. Otherwise the method of operation is not essentially different from that already described. The rate at which a road can be graded up with a grading machine var-ies to a great extent, and depends largely on the character of the soil. Where the original cross section of the ground is approximately level, and the soil conditions not un- favorable, a grading machine drawn by six well-trained horses should cut-out the side ditches and shape the road in from 20 to 35 round trips. Allowing for a reasonable amount of lost time, the rate at which the team travels should average from 1^/2 to 2 miles per hour, and under the circumstances assumed above, the length of road graded per day should average not less than one-fourth mile. Such favorable conditions seldom are found for any considerable stretch of road, except in the prairie 326 HANDBOOK OF EARTH EXCAVATION section of the Middle West, and the average rate of grading with a grading machine is, therefore, much less than one-fourth mile of road per day. Finishing the Surface. No matter how the grading of an earth road may be accomplished, it usually is economical to bring the road surface to its final shape by means of a grading machine. In making excavations it is not generally considered practical to form the crown and side ditches with scrapers or hand tools alone, and the cross section is, therefore, frequently left approxi- mately flat. The grading machine is then used, in the manner already described, to produce the required cross. section. Construction Costs. In the following statements and data an effort is made to show the approximate range of cost rather than the average. The following data (Table I) are intended to furnish a rough guide in making estimates of grading cost at a flat rate per cubic yard. They are based on labor at 15 ct. per hr.; horses at 12^ ct. per hr. The depreciation of grading equipment and repairs are figured at 5% per mo. while in use, and it is ex- pected that the force will be organized economically and man- aged efficiently. TABLE I GRADING MACHINE WORK Assumed conditions : Original cross section flat ; team to consist of six to eight well-trained horses ; no material moved longitudinally. Character of soil Cost per mile Light prairie, free from stumps, roots, etc ^ 60 to $ 80 Average clay loam 100 to 150 Heavy clay, moderate amount of sod and roots, plowing necessary throughout 200 to 250 Heavy clay, exceptionally difficult conditions From $250 up Crowning and shaping road which has been graded with scrapers, etc 50 to 75 Prof. A. B. McDaniel in Engineering Record, July 31, 1915, states that in a case of road construction in VanBuren County, Iowa, a 60-hp. gasoline tractor and graders of so-called " recla- mation " type were used. Sixty miles of earth road was built at a cost of $20 per mile. The road measured 30 ft. from cen- ter to center of the side ditches, which had a width of 20 in. and a depth of 36 in. The earth was the ordinary loam and clay of the prairie country. The " reclamation " type of grader has pivoted axles, so that the wheels can always be kept in a vertical position; thus the weight of the machines is utilized to counteract the side pressure of the earth on the mold-board, and prevents side draft. Where .a large amount of road construction is included in one job, it is economical to use a traction engine for hauling the grader. SCRAPERS AND GRADERS 327 Two graders may be hauled by one engine, and thus serve to move the earth from the ditch to the center of the road at one trip. Tractor Grading. Engineering and Contracting, Oct. 4, 1916, gives the following: Tractor-grader outfits are being used ex- tensively in Utah on highway work. One of the most notable undertakings with these outfits was the construction of approxi- mately 100 miles of earth road in Box Elder County. This work was carried out in 1914 by the State Road Commission. The highway was constructed over a virgin soil, sage brush country, on a new location encircling the north end of Great Salt Lake. It extends southwestwardly from Snowville to intersect the Nevada line just west of Lucin and forms part of the Midland Trail. Two International Harvester Co.'s Mogul gasoline, 60-hp. traction engines and two road graders haitdled the work almost exclusively. A cross section 24 ft. wide from gutter to gutter /*/-, -> C4C Fig. 35. Cross Section of Midland Trail, Box Elder County, Utaiu with 9-in. crown above the shoulders was adhered to almost entirely, the width of the road being increased, however, to 30' ft. in width, through towns and settlements. The cross section mentioned is shown in detail in Fig. 35; The progress of the grader and traction work on the longer tangents of the road amounted to an average of 1^4 miles per 10-hr, day, the cost being $75 per day, or a unit cost of $60 per mile. The record run made on this project for grader and tractor work was 2y 2 miles per day at the same rate, amounting to only $30 per mile of road, thereby surpassing all previous records for speed and economy of road construction in the state- Surveying, clearing right of way, plowing and finishing, however, amounted to considerable; moreover, many stretches required team and hand construction. The average cost of the 100 miles of road was $275 per mile, not including bridges and culverts. Two Road Graders Used with a Tractor. The following is from Engineering and Contracting, May 15, 1918. Using power machinery only, 125,000 cu. yd. of dirt were moved last summer on an Illinois road job, at a cost of 4.1 ct. per cu. yd. The. 328 HANDBOOK OF EARTH EXCAVATION work was done in connection with the improvement of a road leading north toward Pontiac, 111. The first 5 miles of this highway was changed from a narrow winding road to a level, well drained all the year road, 60 ft. wide between fences and 40 ft. wide between drainage ditches. The work of clearing the right-of-way was started on May 1, 19.17, and completed June 16, 1917, during which period 5.18 acres were cleared of a tangled mass of brush and shrubs and over 200 live trees from 3 in. to 3 ft. in diameter. Trees were pulled by a 75-hp. caterpillar tractor using a 100-ft. cable. Two cable outfits were used, so that the tractor was not delayed Fig. 36. Leveling Crown with Graders. waiting for hitches to be made. The cost of clearing the roadway, including labor, interest on investment and an allowance of 20% for depreciation of equipment, was $990, or $191 per acre. The grading was started on June 18, 1917. One 75-hp. cater- pillar tractor was used to pull two Western graders, one 12-ft. to make the cut, followed by an 8-ft. to carry the dirt to the cen- ter of the road. A Western elevating grader pulled by a 75-hp. caterpillar tractor was used in some places in making fills. However, on some of the deeper fills it was necessary to use some other method, in order to make time> and a 75-hp. caterpillar tractor was used in connection with a caterpillar land leveler. This land leveler is a tool used extensively in the West and is in reality a large scraper having a capacity of approximately 3y 2 yd., see Chapter VI. With this machine the dirt could be SCRAPERS AND GRADERS 320 taken up and carried across the road and then unloaded gradu- ally or at one time, as conditions required. The gravel for the surfacing of the road was taken from a near-by creek with a dragline excavator which delivered it to a loading hopper. With the dragline excavator working steadily it was possible to keep the hopper filled, so that when the tractor trains came up, w r hich consisted of one 75-hp. caterpillar tractor and six reversible trailers, they could be loaded without delay or without shoveling. With this equipment a total of a little over 125,000 cu. yd. of dirt was moved in 75 working days. The total cost, including labor, interest on investment and an allowance of 20% covering Fig. 37. Caterpillar Land Leveler on Road Work. depreciation on equipment, was $5,147, or 4.1 ct. per cu. yd. At no time were more than 8 men, including the superintendent, employed on the job. Horses or mules were not used at any time in the work. A Large Drifting Scraper and Tractor is described in Engineer- ing and Contracting, Feb. 19, 1919. In developing the 70,000-acre tract of the Crocker-Huffman Land & Water Co. at Merced, Cal., several interesting dirt-moving methods were employed by Mr. Henry Lage, manager of the company. In building the irriga- tion ditches the dirt was loosened by a scarifier hauled by a caterpillar tractor. Scrapers and mule teams were employed in scooping out the dirt loosened by the tractor and scarifier. Pre- vious to the use of the outfit, the dirt had been loosened by means 330 HANDBOOK OF EARTH EXCAVATION of road plows pulled by mule teams. Five 16-mule teams were used in this work and each plow required three men to hold it, in addition to the driver. For the five outfits, 20 men were required, which at $2.25 made the labor cost $45 per day. The total cost, figuring the 80 mules at $1 each per day, amounted to $125. With the tractor and scarifier outfit the cost of loosening the dirt was $18 per day the cost for the tractor and the operator. One of the greatest problems in- connection with the develop- ment was the leveling of the land. Livestock was first used for the purpose, 400 mules being employed with fresnos. Later caterpillar tractors were substituted for the mules, one tractor being used with seven fresnoes. The difficulty with this method was that one man was required with each scraper, and with seven men in each battery of scrapers, it was difficult to get the unity of action necessary to make the work completely suc- cessful. Mr. Lage then proceeded to experiment and finally brought out a land leveling machine which he termed a ground plane. With this plane he was able to do as much work as he had heretofore accomplished with 24 mule teams and fresnoes. The plane has since been developed and improved by the Holt Mfg. Co. and is now known as the Caterpillar Land Leveler. The machine is designed and built especially for use with tractor power. In the largest size (11^ ft. leveler) the bowl is 2 ft. 5 in. high and the wings extend 3"^ ft. forward. The capacity is 4 to 5 yd. The smallest size (6 ft. leveler) has a capacity of 2 to 2i yd. The bowl is raised or lowered while the leveler is in motion by a power device, consisting of a sprocket keyed to the axle and another one running loose on the upper shaft but attached to a friction cone clutch by means of which the connection between the drive and shaft is made. When the machine is standing still the bowl can be raised by a large hand wheel. The depth of cut thus can be regulated, and the load dumped in one place or spread evenly. Road Grading and Dragging with Tractor. The following ac- count appears in Engineering and Contracting, April 2, 1919. By using a light tractor for hauling in grading the Road Com- missioners of Marquette county, Michigan, were able to carry out work equivalent to that accomplished by a 3-team grader outfit. The tractor-grader outfit was used for trimming of shoulders and reshaping grades when the work was light. In the grader work, it was found that the machine made cuts, which were nearly equivalent to two team cuts but not quite as heavy, that it operated nearly twice as fast as teams successfully, but that any higher speed was too fast to do the work well. It was SCRAPERS AND GRADERS 331 therefore considered that the tractor, taking into consideration its power plus its effective speed, replaced from two to three teams in such work. It is planned to use the tractor con- tinuously on a section gang, combining two of the sections, where team hire is difficult, and putting on a section gang in- stead of having a patrolman and a drag man for each section. A light tractor also was employed during the 1918 season in dragging operations. In this work the drag man found that he could make his section in approximately 5 or 6 hours, entirely covering it, during the period when his section was all in the proper condition of moisture for drag maintenance. The section in question, is a stretch on the outside end of one of the county roads and is entirely wooded. Dragging with horses, it took a full day of 10 hr. and often an hr. or two overtime to cover the section. K. I. Sawyer is County Road Superintendent. Earth Moving Methods and Equipment for Road Construction are described by A. R. McVicar, in Engineering and Contracting, April 2, 1919. Cost of Grading with Drag or Slush-Scrapers in order to do good work with the scraper it is necessary to have the ground properly plowed and, therefore, we must select the proper plow. As for the long handled farm plow, on account of the shape of the mould board, in stiff clay or gumbo, this plow simply turns *the furrow over, leaving it almost, if not entirely, intact, making it almost impossible to load into a scraper. The railroad plow, on account of the abrupt out-turn of the mould board, leaves the furrow broken into short chunks, a proper condition for loading. All classes of earth, no matter how loose or soft, require to be plowed, for the reason that you will find a certain suction in unplowed earth that does not exist in plowed earth. It is neces- sary to plow narrow at all times, and for shovels or slush- scrapers, as deeply as possible. It is not necessary nor ad- visable to plow so deep for wheelers. I would like to make this claim for the slush-scraper, that there can be more earth moved in the same time for less money with the slush-scraper than with any other device known. That is to use it where and how it is intended to be used, viz., making a side fill, a side cut and fill, or wasting a cut to a depth of not more than 6 ft. It takes five scraper holders and one 4-horse plow team and ten " slusher " teams to make a complete gang, the ten scrapers to be divided into five swings, with one holder and two teams to each swing, with one swing to every 100 ft. of road. By keeping the teams going in a circle they will move 1,080 yd. per day, or an average of 90 yd. per team, plow teams included. 332 HANDBOOK OF EARTH EXCAVATION At a rate of $6 per team, the cost per team and half the time of a scraper holder would be $7 per day; that would be moving this earth for 7% ct. per yard. Taking an end haul of 100-ft. distance, including the turn at either end would bring the round trip up to 250 ft. Traveling at the rate of 2y 2 miles an hour, eight scraper loads per cu. yd., would be moving 30 yd. per team, costing 21% ct. per yd. Two No. 3 wheelers, one snatch team, one 4-horse plow team, two wheeler-holders and one dump man on this same haul at a total cost of $36 per day will move 300 yd. or an average per team of 60 yd., bringing the cost, per cu. yd., moved at 12 ct. Increasing this haul to 200 ft. with the slushers would bring the cost per yd. to about 21 ct., an extra cost of 9% ct., while the cost with the wheelers would increase to 14i ct. per yd. or an extra cost of about 2} ct. By these figures you will see that the economic limit of the slusher haul is where you leave the circle. The limit of the wheeler haul is about 600 ft. But in the event of replacing the wheelers with dump cars the limit should be considered 400 ft., being the distance where the cost of wheelers equals or exceeds that of the cars. Grading with Grader or Road Scraper. I have tried out the road grader drawn by two teams of horses that proved very satisfactory. Then I tried three teams. This was more of a success, but altogether too expensive. I then secured two 8-16 hp. kerosene tractors, which proved to be a little on the light side. I then got a 10-20, which seems to be alright. I have been told that the 10-20 is also too Hght, but that is a matter of opinion, as I believe that the tractor is heavy enough for the grader and that the grader is heavy enough for the work I have to do. The earth can be taken off the roadbed or onto it in better shape by going twice over it with this light outfit than by pulling up a conglomerate mass of lumps and stones with one turn of the heavier outfit. We have in connection with this outfit a van in which the operators live. We usually leave this van about 1 mile from the end of the road and work both ways from it. In starting work where the ditches are formed, that is, after a fashion, we have the sods removed from the outer edge of the ditch towards the fence, that is, where the roadbed is not the required width. Next, I have the sod shoulders on the roadbed removed toward and then across the ditch on to the boulevard. This being done, if we find that the ditches are deep enough for proper drainage and the center of the roadbed high enough, we- then continue to heel off more from the shoulders. This earth follows the sod to the boulevard. By doing this we are SCRAPERS AND GRADERS 333 forming the crown of the road as well as lessening the apparent depth of the ditch, although in reality deepening it. Next the grader passes up and down the center of the road with plenty of pressure on the blade to remove all the solid lumps. This is to have as smooth a surface as possible to' receive the loose earth which is to come up from the ditch in the finishing process. Having this smooth surface to receive the loose earth is as neces- sary as to have a smooth and uniform surface on which to lay a permanent pavement. This road, when finished, has a width of 24 ft. and a crown of 12 in. A Gasoline Tractor on Road Work. Mr. G. R. Buchanan in Engineering Ncivs, Aug. 27, 1914, presents some very interesting data regarding the use of gasoline traction engines on road work in Caroline County, Va. The type of tractor selected was a combination kerosene-gasoline tractor, costing $3,000. This trac- tor developed 50-hp. on belt pull and 25-hp. on draw-bar pull. More tractive power was developed on gasoline than on kerosene, and while the former fuel was more expensive it developed that 1 bbl. of gasoline lasted as long as 1.25 bbl. of kerosene. The fuel tank was of 1-bbl. capacity, and this lasted from 7 to 10 hr. when the machine was running. Grubbing was attempted with the tractor but, after a few successful efforts, the gears were badly smashed. In one case, damage to gears amounting to $150 were made on a tree stump which could have been blown u.p with dynamite costing less than $1. Probably if the belt power of the tractor had been applied to a stump puller it might have proved successful. The tractor regularly hauled when grading two large size Buckeye road graders of a much heavier type than are commonly used in the South. These machines when hauled by mules re- quired six animals. In hauling with the tractor the graders were set very much deeper than it was possible when hauling with mules. One grader was hitched with an angle-coupling so that it ran in the ditch, with the steering gear locked to hold it in that way. This obviated the necessity of the steers- man required with mule graders. The second grader was hitched to a double-length pole, so that it followed the first grader and caught the dirt thrown from the ditch, and pushed it further toward the ground. Work was done with tractor-drawn grader in two trips which required no less than ten trips of the mule drawn grader. There is some work that tractors can not possibly do, such as light hauling, patching ruts, and filling from borrow pits. It was estimated that the tractor moved earth for 2..S ct. per cu. yd., which by mule power had cost 3.2 per cu. yd. These figures 334 HANDBOOK OF EARTH EXCAVATION covered labor, fuel, lubricating oil, etc., for the tractor, and feed, stable cost, labor, etc., for the mules, but not depreciation charges. The depreciation of the tractor during the season was figured at $800, while a maintenance account of repairs of about $400 was incurred. This repair charge was largely due to breakage in gears resulting from stump pulling. During the season the tractor moved about 100,000 cu. yd. of earth, which gives a depreciation and repair cost of $0.0012 per cu. yd. Bibliography. " Hand Book of Construction Plant," Richard T. Dana.. " Roads and Pavements," Ira O. Baker. " Excavating," Allen Boyer McDaniel. " Highway Engineers Handbook," Harger and Bonney. '' Earth Dams," Burr Bassell. " Irrigation Works Constructed by the U. S. Government," Arthur P. Davis. " The Use of Hoisting Engines for Loading Wheeled Scrapers on the Goulburn-Warango Water Works, Victoria, Australia," G. H. Dunlop, Kng. News, June 23, 1904. " Construction Work on the Southern Indiana Railway," Eng. News, Feb. 25, 1904. CHAPTER X METHODS AND COST WITH CARS General Types of Contractors' Cars. Cars used for hauling earth may be divided into four general classes: Non-dumping cars, '" static " and " rotating " dumping cars and tipple dumping or mine cars. Non-Dumping Cars consist almost entirely of the standard broad gage railroad flat cars. They are loaded in various ways, one of which is by a special type of steam shovel known as a railway ditcher which is mounted on a track on top of the cars and which works its way along 'the train filling the cars behind it. These cars are emptied by drawing a heavy plow unloader Fig. 1. Loading Non -Dumping Flat Cars. attached to the locomotive by cable from one end of the train to the other. Static Dumping Cars are so arranged as to hold the burden in a quiescent state, and are unloaded by the opening of a gate in the bottom or side, allowing the load to flo.w gradually out. Their greatest effectiveness is obtained in discharging an easily- flowing burden containing a certain amount of " life " that is, a material that does not adhere to itself or the car, such as sand, 'rock, gravel, etc. Rotary Dumping Cars are mounted trucks which remain sta- tionary while the body is overturned or tilted at an angle sufn- 335 336 HANDBOOK OP EARTH EXCAVATION cient to discharge the load either to one side or the other. \Yhile the body is in process of being tilted, the sides or gates for retaining the burden are automatically lifted or lowered or swung outward, so as not to interfere with the sliding movement of the load in process of dumping. There are two classes of car L ^ I . '~'*y tt ' M "*L'? :v^_ SECTIONTMo-CeNTEHrCAR. SET CnONTMno'CCNTER or BOLSTER. Fig. 2. The Goodwin Patent Dump Car. included in this type, those requiring individual dumping and those dumping by air or other means making it possible to discharge a whole train load at once. Rotary cars are particu- larly adapted to the carrying of clay, earthy soil, alluvial ma terial, etc. They are generally used for hauling earth. METHODS AND COST WITH CARS 337 Fig. 3. 30-Ton Side Dump Car. Fig. 4. 3-cu. yd. Side Dump Car (Made by Kilbourne and Jacobs Mfg. Co., Columbus, Ohio). Wheel Base 48 in., gage 36 in., Weight 4,300 Ib. .338 HANDBOOK OF EARTH EXCAVATION Rocker Double Side Dump Cars are widely used on construc- tion work. Fig. 5 shows a car of this type made by the Easton Car Construction Co., of Easton, Pa. These cars are made for capacities of from 18 cu. ft. to 135 cu. ft. and weigh from 900 Ib. to 6,900 Ib. Tipple Dump or Mine Cars can only be used in connection with an automatic dumping device. In general the car is tilted truck and all and at the same time an end gate is held open until the material slides out. Fig. 5. Rocker Double Side Dump Car. Track Mover. Samuel A. Taylor, in an address before the Railway Club of Pittsburgh, in 1911, gave a description of a track moving machine which is used on earth dumps. The operation is described as follows: When the fill has been made to such a width that they wish to move the track over, the track mover, consisting of heavy chains and hooks hanging from the end of a boom, takes hold of the track and lifts it until the ties are clear of the ground. Then a side arm, in which is placed a pulley on which a wire rope passes, having hooks attached to the end, is then fastened to the rails. This rope is operated by a small engine, which swings it over to its new position. That METHODS AND COST WITH CARS 339 machine displaces a great deal of labor and is very economical in cost of operation. A Track Throwing Car. An interesting device, invented by Davis Creerse, was described and illustrated in Engineering News, Dec. 21. 1899. This apparatus (Fig. 7) is fitted to the rear end of a flat car. It consists of -a timber frame on which is a hand hoist operating a bull pole. The end of this pole carries a 14-in. wheel which, when the machine is in operation, bears against the web of the outer rail. When in operation the car Fig. 6. Tipple Dump Car Made by Austin Mfg. Co., of Harvey, 111. is heavily loaded with iron rails and is hauled over the track, the " bull pole " throwing the track at the rear of the moving car. The track may be shifted any distance from 6 in. to 3 ft. Switch for Narrow Gage Tracks. Fig. 8, which is taken from Engineering and Contracting, Sept. 28, 1910, shows a contractor's switch which is very simple of construction alid operation. It is also quite rigid and strong enough to carry heavy loads with- out a great amount of wear. The idea, as shown, is in joining the two inside rails together as a switch point and shifting the point back and forth between the outside rails in the positions indicated on the plan. The ties are capped with i/ -in. plates a.s wearing surfaces and the switch points are brace! rigidly. The design is the idea of Mr. C. R. Neher, who is constructing en- 340 HANDBOOK OF EARTH EXCAVATION METHODS AND COST WITH CARS 341 gineer for the Atlantic, Gulf & Pacific Co., at Whitehall, N. Y., and the switch has been used in the contract work of this com- pany in a number of places. Use of Cars. In ordinary construction work light (3-yd.) cars are generally run on light rails (16 to 40 Ib. to the yard) with ties wide spaced (4 ft. c. to c. usually) and not ballasted. To lay such track with labor at 30 ct. per hr. has cost the author about $4 per 100 ft. of track, or $200 per mile, after delivery of materials. The author has used 4 x 4-in. ties, but cannot recom- mend them, for after once using they are so split by the spikes Fig. 8. Details of Special Contractor's Switch. as to be of little value. A 6 x 6-in. tie, 5 ft. long, is the best for general use on these narrow-gage roads. Roughly laid as such track is, with light rails, and wide spacing of ties, it is not safe to estimate the rolling resistance at less than about 40 Ib. per ton of load on the car wheels ( including the weight of car itself) on a level track. It is very commonly stated that 20 Ib. is the force required to pull a 2,000-lb. load over light rails. This- may be so over carefully laid, clean track, with ties close-spaced, and with car wheels well lubricated; but over the ordinary rough contractor's track, 20 Ib. is much too low an estimate. In the " Coal and Metal Miners' Pocket Book " is a table giving actual results of traction tests, including several hundred separate tests under varying conditions. From these tables we have summarized the following: 342 HANDBOOK OF EARTH EXCAVATION Per short ton Pull to start mine cars (old style) loaded 90 Ib. Pull to start mine cars (new style), empty 80 Ib. Pull to keep up ^4-mile per hr. speed (old style car).... 50 Ib. Pull to keep up %-mile per hr. speed (new style car) 33 Ib. Pull to keep up 4 1 /-mile per hr. speed (old style empty) 56 Ib. Pull to keep up 4^-mile per hr. speed (old style full) 66 Ib. Pull to keep up 4^-mile per hr. speed (new style empty) 30 Ib. Pull to keep up 4%-mile per hr. speed (new style full) 38 Ib. The foregoing was for trains of 1 to 4 ears, but with a train of 20 cars the pull was 46 Ib. for old-style cars and 26 Ib. for new-style cars per short ton on a level track. The mine cars used had a wheel base of 3.5 ft; they weighed 2,140 to 2,415 Ib. empty and 7,885 to 9,000 Ib. loaded. The diameter of the wheels was 16 in., and of axles 2} in. for old-style car to 2^ in. for new-style car, with a steel journal 5^4 in. long, well lubricated in all cases, in fixed cast-iron boxes. The new-style cars had better lubrication, the importance of which is well shown by the results of the tests. The track in the mine was level and in good condition. The resistance to traction on upgrades is practically 20 Ib. per short ton for each 1% (1 ft. rise in a 100 ft.) of upgrade; so that on a 5% grade, for example, it will require a 100-lb. pull on a rope to overcome the gravity resistance of a ton, plus 40 Ib. more to overcome the rolling resistance, or a total of 140 Ib. per ton. Working steadily for 10 hr., a single horse can just about do the work necessary to pull a car up a 4% grade, that is the tractive force of a 1,200-lb. horse is about 120 Ib. working steadily all day long; in other words, a horse can exert a pull on a rope of about ^Q its own weight. Many a con- tractor will say that this is absurdly low, but experience has shown it to be not far from right. However, for a short time a horse, like a man, can exert a great deal more force. The author has had a heavy team pull a load of 10,000 Ib. up a 5% grade on a macadam road; and actual test on a spring balance has shown that a light pair of mules have exerted a pull of 1,000 Ib. (or 500 Ib. each) ascending a steep earth road. So it is evident that for a few minutes a horse can exert a pull about 500 Ib. if he has a good foothold, but he must have long rests between such exertions. It requires about two times as much force to start a car as it does to keep it in motion, hence a horse should never be worked within half his capacity, that is he should not be required to exert over 250 Ib. pull at any place where cars are apt to stop. A dump car with a box 2 ft. deep, 5 x 5.5 ft., holds 2 cu. yd. water measure, but even when heaped up with loose earth it will seldom hold 2 cu. yd. of earth measured in cut. Such a dump METHODS AND COST WITH CARS 343 car weighs about 2,000 Ib. and 2 cu. yd. of earth (place measure) weigh about 5,400 Ib., or a total of 7,400 Ib., or 3.7 tons. A strong horse could pull one such car loaded on a level track all day long, and could go up a short 4% grade occasionally if he did not stop on the grade. Cars will coast down a 2% grade -once they are started, so it is not advisable to have steeper grades, when brakes are not provided for the dump cars. Mr. P. B. Lieberman in a paper in Trans. Am. Inst. M. E., Vol. LV, 1917, gives the result of tests made at the Greensburg Coal Co.'s mine at Greensburg, Pa., on mine cars with and without roller bearings. His conclusions were that the use of roller bearings reduced the draw bar pull 47% on speeds of between 5 and 6 miles per hr. On the Chicago Drainage Canal a great deal of material was loaded with a steam shovel into small dump cars that were hauled away by horses on a slightly down grade to the foot of an " incline," where they were pulled with a %-in. wire cable to the top of the bank by a 60-hp. winding engine (13x 16-in. cylinder) stationed at the top of the bank; the cars were then hauled to the dump by horses. One team pulled two cars holding 3 cu. yd. each, or five cars holding 1 cu. yd. each. The same team could pull back 6 empty 3-cu. yd. cars. Two faces were worked in opposite directions from each " incline." Even then the " in- cline " engine could handle more material than two shovels could excavate. In one case 2,400 cu. yd. were raised in 10 hr. An extra team was used to " spot " the cars. ( See Gillette's " Rock Excavation.") In excavating mud the author once used an incline 120 ft. long rising 12 ft. in that distance; then there were 80 ft. of level track at the foot of the incline and 40 ft. of level track on a trestle at the top. Using a team of horses and a single car holding 1 cu. yd., with a hemp rope passing around a pulley at the top of the incline, 120 carloads were raised every 10 hr. The team actually traveled 14.5 miles a day in doing this work, part of which it will be seen was exceedingly hard. There are many comparatively small jobs where a few dump cars and some light rails will enable a contractor to move earth far cheaper than with wagons. Ordinarily the dumping of the cars where the fill is light will cause the earth 'to run back and block the track. It is therefore customary first to build a tem- porary trestle, and fill it in with earth; then the track is shifted from time to time to keep it close to the edge of the embank- ment. Even where the fill is so light as not to pay to trestle, the author has found cars economic; for then the earth can be shoveled from the cars at a cost of 12 ct. per cu. yd. (wages 344 HANDBOOK OF EARTH EXCAVATION being 30 ct. per hr.), which is often less than the added cost of hauling with wagons. Cars Moved by Hand. In excavating narrow open cuts, or tunnels either in earth or rock, a small dump car running on 16-lb. rails is often used with profit. A man can readily push a small dump car holding y 3 cu. yd. of earth (nearly half a ton) on a well laid, clean level track at a walk of 220 ft. a minute all day long. With wages at 30 ct. per hour the cost of moving earth in this way is 1.5 ct. per cu. yd. for every 100 ft. of haul, which it will be seen is very much less than the cost, 10 ct. per cu. yd., by wheelbarrows for every 100 ft. of haul. In view of this low cost, and in view of the ease with which a 16-lb. track can be laid and shifted when made in one rail sections, it is surprising the contractors do not oftener use the small end dump car pushed by a man. Cars and Portable Track. G. P. Blackiston in Engineering and Contracting, July 13, 1910, gives the following: An immense bank of special earth was practically encircled by a deep canyon with the exception of a very narrow stretch of land connecting the mainland as it were, with the high bank. The margin of profit being small, ordinary methods of trans- portation were out of the question. The length and narrowness of the stretch of connecting land did not permit the use of wagons or carts, while the use of steam shovels at the working end was quite out of the question due to the impracticability of transporting the shovel to the bank. The use of dump cars operated upon portable tracks was also impracticable unless they could be loaded with .the minimum of labor. This, there- fore, meant that the material could not be transported at any distance in shovels from the bank to the cars; in short, that the cars must be placed at the very feet of the laborers shoveling permitting them to transfer the earth directly from the bed to the car yet there was no room for a vast complicated system of switches. With all this to contend with, the contractor laid a portable railroad across the narrow strip of ground to the bank. Here, by means of several short spurs, Fig. 9, he placed his cars abreast at the distance of about 10 ft. apart. This permitted the laborers to load the respective cars from three sides and without moving a step to secure the load. As the work prog- ressed another section of the portable track (attached to steel ties) was laid and the next cars loaded at a position closer to the base of supply. The cars when loaded were conveyed by gravity to the unloader on the opposite side of the ravine, some 626 ft. away. METHODS AND COST WITH CARS 345 By this method coupled with the use of steel dump cars and portable tracks made by the Orenstein-Arthur Koppel Co., Pitts- burgh, Pa., the material was loaded, conveyed and dumped for less than 6.3 ct. per cu. yd. 'NT Fig. 9. Track Arrangement for Loading Cars by Hand. Cost with Horse-Drawn Cars. Hauling cars with horses is ordinarily cheaper than with locomotives for short distances, unless the contractor already has the locomotives on hand. Referring to the forepart of this chapter, it is seen that a strong team will pull about 5 cu. yd of earth over fairly level track at a walk. With a speed of team 2.5 miles an hour, the cost is 1430 of an hour's wages of team and driver per cu. yd. for every 100 ft. of haul from pit to dump. At this rate it is as cheap to haul with horses as with locomotive up to a distance of nearly a mile, provided, of course, that a contractor has to rent or buy the locomotive, and does not already have it on hand. A locomotive, however, possesses one decided advantage in that it can push cars out into a trestle; whereas, a block and tackle must be used with a team to get the cars out onto the trestle. If there were no delays either at the pit or at the dump, and a team were moving all the time, we thus see that it could haul 3,300 cu. yd. 100 ft., or 100 cu. yd., 3,300 ft. Mani- festly the first rate is impossible not only because there are necessary delays, but because enough men could not be got^ 346 HANDBOOK OF EARTH EXCAVATION around the cars to load 3,300 cu. yd. a day. Ordinarily where cars and a team of horses are used about 20 shovelers are employed, seldom more than 30 shovelers, not infrequently only 10. Ten men working at a face of earth may each undermine and load 15 cu. yd. a day, which a team could haul in cars a distance of 2,200 ft., making 30 round trips if there were no delays. As a matter of fact there will be about two minutes consumed each trip changing team from the empty to the full cars, and another four minutes at the pit dumping. Delays while shifting track will ordinarily add about four minutes more each trip, making a total of 10 minutes "lost time" each trip, or two minutes for each cu. yd. This means a cost of } -hr.'s wages of team and driver for lost time per cu. yd. hauled. In this 10 minutes "lost time" the team could travel 1,100 ft. and return; hence, instead of travelling 2,200 ft. and return as above assumed, the team would really have time to travel only halt that far. Rule. To find the cost per cu. yd. of loading from a " face " and moving average earth with cars and horses, add together these items: %-hour's wages of laborer undermining and shoveling earth. %0-hour's wages of team with driver " lost time." ^-hour's wages of man on dump, dumping, making trestle, and track shifting. Then add ^oQ-hour's wages of team with driver for each 100 ft. of haul. With wages of man at 30 ct., and horse at 15 ct. per hr., this rule becomes : To a fixed cost of 32 ct. add 0.2 ct. per cu. yd. for every 100 ft. of haul; and add the cost of materials for the dumping trestle plus $250 per mile of track, divided by the total number of cu. yd. moved over the track before it is torn up. NOTE. Where a steam shovel is used, hauling cars by horses is especially disadvantageous because of delays in switching and " spotting " cars in such short trains as team hauls. Cost with Horse-Drawn Cars. The cost of excavating and transporting earth with Koppel 1.5-yd. V-shaped dump cars at Attleboro, Mass., is given in Engineering and Contracting, Sept. 30, 1908. These cars were operated on a 30-in. gage track, and were 4 ft. 5 in. high, and about 5 ft. 7 in. wide They weigh 1,080 Ib. Some of them were equipped with brakes. The cars were operated in trains of 4 cars, and coasted to the dump by gravity, being hauled back to the cut by one horse and a driver. Thus five horses were used for the 40 cars. The dead load pulled back by the horse was about 4,400 Ib. A 20-lb. rail was used, laid on METHODS AND COST WITH CARS .14? wooden ties, spaced at 3-ft. centers. In all 2.25 miles of track was used on the job. Several turn outs and switches were used, thus allowing the cars to be kept almost continually in motion. The total cost for plant outside of small tools was: 40 cars at $90 $3,600 70 tons rails at $32 2,240 4,000 ties at 12% ct 500 Total $6,340 Estimating interest, depreciation and repairs to the outfit at 2% per month, we have a monthly charge of about $127 for plant. The material was a boulder clay, consisting of loam, clay, gravel and hardpan, and while most of it required but little loosening with picks, yet some of it had to be drilled with short holes and shot with 20% dynamite. Some of the work, where the banks were low, was worked from on top, but most of it was worked from abreast. Men shoveled the material with short handled shovels. The excavated material was hauled from 700 to 1,000 ft., the average haul being about 850 ft. There were 80 men employed on the job working under 3 foremen.. A 10-hr, day was worked. During the month of June in 25 working days, 15,000 cu. yd. of material were excavated. The cost for this work was as follows : 3 foremen, 25 days at $5 $ 375.00 75 men, 25 days at $1.80 3,375.00 5 drivers, 25 days at $1.80 25.00 5 horses, 25 day's at $1 125.00 300 Ib. dynamite at 10 ct 30.00 Plant charges (estimated) 127.00 Total for 15,000 cu. yd $4,257.00 This includes all the cost except general expenses, and the month's proportion for laying track. The item of transporta- tion for an 850-ft. haul is low, since it amounts to only % ct. per cu. yd. per 100 ft. of haul. The total cost was 28.3 ct. per cu. yd. Comparative Costs with Wheelers and Cars. The following data of the cost of grading 25,000 cu. yd. of average earth for a railroad siding near Homewood, Pa., is given by Mr. Arthur. Reiche in The Industrial Magazine, Aug., 1907. Part of the work was done by scrapers and part by Koppel 1-yd. double- side dump, V-shaped cars. The car work was in a wide cut and borrow pit, the bank averaging 5 ft. in. height. Two-thirds of the material was aver- age earth, the remainder being ha r d gravel requiring a three- horse rooter plow for loosening. 348 HANDBOOK OF EARTH EXCAVATION Portable track of 24-in. gage with steel ties, was used. The cars were hauled in two trains of four, a train being pulled by one horse. Dumping was from a trestle about 20 ft. high constructed of round timber cut locally. The average haul was 650 ft. Temporary spur tracks were laid over the cut and the plowing done on each side of them. (It has been the ex- perience of the author that, when the depth of cut is 4 ft. or more, it is economical to work at a face, undermining the earth, or plowing it with a sidehill plow, rather than working from the top. This is particularly true in hard material where a few light charges of powder will loosen a large quantity of ma- terial much more cheaply than with a plow.) The labor costs on the car work were as follows: 1 foreman $3.00 16 shovelers at $1.65 26.40 1 plow team and driver 7.50 1 horse and driver 3.50 3 dump men at $1.65 4.95 1 track man 2.00 Total per 10-hr, day $47.35 The wheel-scraper work was nearly all borrow-pit work, the soil being easily plowed by a 3-horse grading plow. No. 3 Western wheelers were used. The daily labor force charges were as follows : Foreman $3.00 2-horse teams 5.00 3-horse snap teams 7.50 2 scraper loaders @ $1.75 3.50 Total per 10-hr, day $19.00 The daily records showed that the cost by car, including the wages of carpenters building the trestle was 24.5 ct. per cu. yd., the average haul being 600 ft. The cost by wheel scrapers was 26.25 ct. per cu. yd., the average -haul being 350 ft. The plant required for the car work was as follows : Double track trestle, 24 in. gage, 6 ft. between centers of tracks, 6 x 8-in. stringers 22 or 24 ft. long, 2 x 6-in. ties on 2.5 ft. centers, 2 x 12-in. running boards between rails, 12-lb. rails, trestle legs of green poles averaging 30 ft. in length at 5 ct. per ft., cost complete $1.50 per lin. ft. of double track trestle, or $225 for 150 ft. erected; five split switches at $18, cost $90; two iron turntables at $30, cost $60; three %-cu. yd. steel cars $190; total $565. Good for 5 yr. with 10% for repairs and renewals. A Motor Truck Hauling Industrial Railway Cars. Engineer- ing and Contracting, Aug. 2, 1916, gives the following: A Four Wheel Drive truck is used in place of a locomotive to METHODS AND COST WITH CARS 349 draw a train of heavily loaded trailers on a narrow gage track. The truck itself straddles the rails, and it is interesting to note that enough traction is secured to pull the 'train easily up a 5% grade, although no load whatever is carried on the body of the truck. The crushed rock, gravel and cement hauled by this outfit are being used in the construction of a 16-ft. concrete highway going north from Sioux City, la., on what is known as the Perry Creek road. The large amount of material hauled is indicated by the fact that from 500 to 600 lin. ft. of pavement are being laid daily. The track is four miles in length and ten round trips are made each day. Each trailer carries n/ 2 cu. yd. of gravel or crushed rock, making a total pay-load of 24 to 26 tons. The truck pulls this load while running in high gear, and travels at 12 to 15 miles per hr. Fifty teams and wagons were unable to do the work which is now being done by this truck and string of trailers, accord- ing to the contractors, and an enormous saving in cost is effected. The average daily cost of operating the truck and trailers in this service is $17. Hauling with Dinkeys. The ordinary " contractor's locomo- tive," or " dinkey," travels on a track of 3-ft. gage. The size of dinkey commonly used weighs 8 short tons, and is listed as having a tractive pull of 2,900 Ib. on a level track. Whether the actual tractive capacity is exactly 2,900 I do not know; but it must be approximately that, for any locomotive can exert a pull of 25% of the weight on its driving wheels even on clean rails. The loads that a dinkey can pull, however, are much over-estimated in catalogues, due to too low rolling resistances assumed for cars. It is said in some of the catalogues that the resistance to traction is 6^ Ib. per short ton. This rate applies only to the best of standard gage railway tracks with heavy rails, well ballasted, and with heavy wheel loads. On a contractor's narrow gage, light rail track, the resistance to traction is probably not much less than 40 Ib. per ton, and where the cars are loaded it is doubtless more, due to the dirt on the rails. The resistance due to gravity is 20 Ib. per short ton per 1% of grade; but, of course, the tractive pow^r of a locomotive falls off 20 Ib. for every ton of its own weight for each 1% of grade. Based upon these data, and upon the assumption that the resistance to traction is 40 Ib. per short ton, an 8-ton dinkey is capable of hauling the following loads, including the weight of the cars: 350 HANDBOOK OF EARTH EXCAVATION Level 1% gr 2% 3% 4% 5% 6% 8% track Total tons 70 ade 46 33 26 21 . . 17 14 10 Note : On a poor track not even as great loads as the above can be hauled. Due to the accidents that frequently occur from the breaking in two of trains on steep grades, and from the running away of engines, it is advisable to avoid using grades of more than 6%. When heavily loaded, a dinkey travels 5 miles per hr. on a straight track ; but when lightly loaded, or on a down grade, it may run 9 miles an hr. The following are the average struck measure capacities of the dump cars made by one firm (variations of weight of several hundred pounds occur, according to the make) : Capacity, cu. yd. . 1 \Vz 2 2% 3 Weight, Ib 1.700 2,000 2,300 2,800 3,500 A car seldom averages its struck capacity of earth measured " in place," even when the car is heaped full with a shovel ; for not only are there vacant places in the corners of the car, but the loose earth is 20% to 30% more bulky than earth " in place." The number of dinkeys required to keep a shovel busy can be estimated from the data given. On short hauls (1,000 ft. or less) one very often sees only one dinkey serving a 1%-yd. shovel. In such cases the dinkey is not heavily loaded, so that it can run fast, and by having enough men to dump a train of 6 cars in 2 or 3 min., a fairly good daily output of the shovel can be secured. In dumping the cars, estimate on the basis of one 3-yd. car dumped by each man in 1} to 2 min. The men work in groups of 2 or 3 in dumping the cars, and enough men are usually pro- vided on the dump to dump a train in 3 min. When two or more dinkeys are serving one shovel, and long trains (12 cars) are being used, it would seem that very little lost shovel time would occur due to switching in an empty train; but, even under favorable conditions, I find that iy 2 to 2 min. per train are lost in switching. This is another reason why a shovel served by only one dinkey makes so good a showing on short-haul work. Still another reason is that at the time the shovel is shifting forward, the dinkey can often make its round METHODS AND COST WITH CARS 351 trip ; and on shallow face work this shifting of the shovel occurs frequently. The method of using a hoisting engine and cable to move the cars is quite common in railroad work, where the hauls are short, say 1,000 ft. or less. The track is laid on a rather steep grade, at least 3% from the pit to the dump, and the cars coast down by gravity usually in trains of 4 cars holding about 2 cu. yd. each. The hoisting engines pull the cars back with a wire rope. A team of horses will have all it can do to pull a train of 4 such cars even on a slight down grade to the dump. As a matter of fact, a team that is working steadily can not be counted on to pull more than two cars holding 3 cu. yd. each, on a level track of the kind ordinarily used in contract work. The 3-ft. gage track commonly used is laid with rails weighing 15 to 40 Ib. per yd. of single rail. A 30 or 35-lb. rail makes a track that is not easily kinked under the loads, even when ties are spaced 4 ft. centers. A 6 x 6-in. tie, 5 ft. long, is the best size. I have tried 4 x 4-in. ties, but they are easily split by the spikes, and are not of much value after being used once; whereas the 6 x 6-in. ties can be laid 5 to 6 times. After the rails and ties are delivered, and the roadway graded, such a track can be laid for $200 per mile, or $4 per 100 ft., when wages are 30 ct. per hr. And the track can be torn up and loaded on wagons for $2 per 100 ft.; there being 1 ton of 30-lb. rails, and 375 ft. B. M. of 6xG-inx5-ft. ties per 100 ft. of track. Trautwine assumes that a contractor's locomotive will readily haul a train of 10 dump cars holding 1.5 cu. yd. each as a speed of 5 mi. per hr. He assumes 9 min. lost time each trip loading and dumping; and a train force as follows: 1 engineman $ 3.00 1 dump foreman 3.00 3 dumpmen @ $1.50 4.50 Vz ton coal @ $3 1.50 Oil, water, etc 1.00 1 switchman 1 .50 $14.50 On these assumptions he figures that a locomotive in 10 hr. will haul as follows : 4.350 cu. yd. with a 1-mile haul. 2,700 cu. yd. with a 2-mile haul. 1,950 cu. yd. with a 3-mile haul. 1,500 cu. yd. with a 4-mile haul. 600 cu. yd. with a 10-mile haul. Trautwine then makes a very serious error, for he entirely over- looks the fact that no steam shovel can load the full 4,350 cu. yd. 352 HANDBOOK OF EARTH EXCAVATION in a day that the locomotive might handle on a 1-mi. haul; and he fails to see that in reality the cost of hauling with a contractor's locomotive does not depend greatly upon the length of haul. In reality it matters very little whether the haul is long or short; for the steam shovel is the limiting factor, and a shovel may not average 500 cu. yd. per day. In widening cuts on railway work it is often necessary to use flat cars holding 5 to 10 cu. yd. of earth, seldom over 7 cu. yd., unless drop sideboards are provided. A flat car is ordinarily 8.5 ft. wide over side sills and 32 ft. long over end sills. In freezing weather the floors of the cars should be sprinkled with brine just before loading, a man with an ordinary garden sprinkler being detailed for the work. The brine will prevent the earth from freezing to the car floor for 3 or 4 hr.; but a loaded car should never be left standing over night, for it will take 4 to 6 men a day to unload a frozen car load of earth. For costs of hauling with dinkeys and cars see Chapter XI. General Types of Light Locomotives. Light locomotives are made to run by steam, gasoline, electricity and compressed air. There are many varieties of each of the four types. Steam Locomotives burning coal are in most general use. Oil and wood burning machines are available. The Shay locomo- tive is a steam machine differing from the usual type in that instead of horizontal cylinders directly connected to the drivers, it has vertical cylinders driving a pinion wheel which in turn is engaged with gear on the driver. The result is an engine of great tractive force and slow speed. Gasoline Locomotives are now being built and their use is increasing. Electric Locomotives are useful wherever current can be ob- tained and used without danger. Both storage battery and con- tact type machines are used. Compressed Air Locomotives are most useful in coal mines and in certain industrial works where there is danger of igniting gas or other combustible material. Their ultimate efficiency is low. Resistance of Rolling Friction. According to the H. K. Por- ter- Company's catalog, the resistance due to rolling friction varies with the character and condition of rolling stock and track. With extra good cars and track it may be as low as 5 Ib. per ton of 2,000 lb.; but 6} lb. may be taken for first- class cars and track, 8 to 12 lb. for reasonably good conditions, and as high as 20 to 40 lb. for bad cars and track, and 60 to 80 lb., or even more, for excessively hard-running cars and very rough track. Cars with wheels fast on axles and suitable bear- ings and oil boxes should not exceed 8 to 12 lb.; logging cars METHODS AND COST WITH CARS 353 ^ O ^ 4P i^s^^ s Ss ^^1 ffl !3 -iS I CO 1 " 354 HANDBOOK OF EARTH EXCAVATION may run 6y 2 to 12 Ib. if of good construction, up to 20 or even 40 Ib. if with poor arrangement for oiling. Contractors' dump cars are usually hard-running, say 10 to 25 Ib.; coal-mine wagons, with loose wheels, are seldom less than 15 Ib., and often exceed 30 Ib. and with the holes in the wheels worn out of true, and the wheels scraping against the sides of the car, may develop 60 to 80 Ib., or even greater resistance. Street cars may be reckoned at 15 to 25 Ib. The resistance of flange friction on wooden rails is an indeterminate quantity, but usually twice the resistance on steel rails. Poorly laid track and crooked rails increase the resistance indefinitely. Overloading cars also increases the resistance greatly. The resistance is greater in cold weather. The resistance of rolling friction per ton is greater for empty cars than for loaded cars. TABLE II. PERCENTAGE TABLE FOR APPROXIMATE COMPUTA- TION OF HAULING CAPACITY Grades Percentages figured to include Frictional Resistances per ton of 2,000 Ib. 1% Grade 2% 3% 4% 5% 10% 11% To obtain the hauling capacity on any grade for track of any frictional resistance, multiply the hauling capacity of the loco- motive on a level for a rolling friction of 6^ Ib. per ton. (This is given in Table I) by the factor given above an:l point off two decimal places. The actual resistance of rolling friction may be determined by noting on what down grade a car once started will just keep in motion. If a car will hardly keep in motion if started down a 1% grade, its frictional resistance is just about equal to 20 Ib. per ton; the same proportion will hold for other grades. Water and Fuel Consumption of Locomotives. The number of gallons required per mile by a locomotive is approximately 1% of the total resistance to be overcome. The total resistance is ex- pressed in Ib. and is equal to 20 times the percentage of grade plus the rolling friction in Ib. per ton, times the total weight of the train, engine, tender, cars and load expressed in tons of 2,000 Ib. The number of Ib. of coal required per mile under the most ;he percentage apacity is 6% Ib. 100 . 23 10 Ib. 65. ro.4 15 Ib. 43.3 17 20 Ib. 32.5 14 5 30 Ib. 21.6 11 .r> 40 Ib. 16.2 93 12 5 11 5 103 9 3 7 7 66 8.3 6 7.7 5 6 7.1 5 3 6.6 4 9 5.6 4 3 49 3 8 4 5 4 3 4 38 3 4 3 . 3.6 2 9 3.4 2.8 3.2 2.6 3.0 25 2.8 9 2.5 2.0 23 2 2 2 1 2 1 8 16 1 9 1 8 1 7 1 6 1 5 1 4 1 5 1 5 1 4 1.4 1.2 1.1 . 1.3 1.2 1.2 1.1 1.0 .9 METHODS AND COST WITH CARS 355 favorable conditions is very nearly the same as the number of gallons of water. Under unfavorable conditions as much as 40% more coal may be required. This relation of coal to water re- quired is based on the assumption that 1 Ib. of coal will evapor- ate from 5 to 8 Ib. of water. Filling in Flats with Dredged Material. (Engineering News, May 27, 1897.) In 1874 work was commenced at Boston for reclaiming the South Boston Flats, and this work consisted of the construction of seawalls and bulkheads of masonry, and the filling of the remainder of the area with dredged materials. The walls were packed with oyster shells and gravel, filling with a slope of 45% from the top of the wall. The material used for filling was stiff clay dredged from the harbor. This was distributed by small cars on tramways and trestles. The con- sistency of the material became semi-fluid by handling, weighing about 125 Ib. per cu. ft., and great care was necessary in de- positing near the walls, it being usually placed in a layer 4 or 5 ft. deep. This layer was left for several weeks in order that it might become consolidated while work was going on in other places. Detailed descriptions of the methods used in 1886 for filling 120 acres are given by Mr. Frank W. Hodgon in Journal of Association of Engineering Societies,- Vol. 7, page 5. The ma- terial used for filling consisted chiefly of blue and yellow clay with some fine sand and gravel in places. This was dredged from various parts of the harbor, placed in scows that were floated at high water over the area to be filled, and then dumped. This process was continued until the filling had reached a height of about 3 ft. above mean low water, that portion dumped being an average of 5 ft. in thickness. To construct the remaining 10 ft. in height of fill the material was redredged from the scows, loaded on cars, and distributed on trestled tracks. The cars as a rule, held 7 cu. yd., but some held 10 cu. yd. The sides were hinged and the bottoms. were shaped like an inverted V, so that half the material was dumped on each side of the track. The cars were first dumped along the entire length of the trestle in order to give stability to the piles supporting the trestle. Then dumping was commenced at the further end of the track. The material after having been handled several times was in a semi-fluid condition and it assumed a slope 20 to 1 or 25 to 1. Great care was exercised to keep the dump moving as otherwise it would dry and set on the surface. Alternate parallel tracks were filled first in order to prevent the filling from forcing adjacent tracks out of line. Material dredged by scoops or dipper 356 HANDBOOK OF. EARTH EXCAVATION dredges in the first place and then loaded into cars by clam shell dredges was broken up more and worked better than when first dug by and also loaded by clam shell dredges. Attempts were made to place the material from cars that had been carried on scows and loaded directly at the dredging site, but this material was firm and would not run from the cars. Other attempts to carry the track directly on the dump instead of on a trestle failed completely because the tracks could not be held up. The dump was leveled by men with wheel-barrows; 150 ft. from the track being about the economical limit of haul. Attempts at spreading the material with scoops drawn first by oxen and later by a hoisting engine and cable were also unsuccessful. Cost with Horse-Drawn Cars and Portable Track. We are indebted to A. W. Sperry for the following data appearing in Engineering and Contracting, Oct. 14, 1908, regarding the use of steel Koppel cars. Six to nine cars were used, of 36-cu. ft. capacity, running on a 24-in. gage track. These cars weigh 900 lb., and stand 4 ft. 2 in. above the top of the rail. They cost about $80 apiece. The rail was of 20-lb. section, costing about $30 per ton. The excavation was made from a borrow pit alongside a rail- road track, with the result that no ties were needed for the dirt track, but the rails were laid directly on the old ties and between the rails of the standard gage track. This is an eco- nomical method when lighter rails are used than those in the standard gage track, but, when the same weight rail is used in both tracks, then it is necessary to lay only one rail for the dirt track, using one rail of the standard gage track for the dirt cars. This effects a considerable saving in money in track. In all 2,000 lin. ft. of track were used. There were 7,000 cu. yd. of material taken from the lower pit, and hauled an average of 1,000 ft., down grade, about one-half being a 2% grade and the other half a 4% grade. In making the fill, at times the rail was laid on grades as high as 8 or 10%. The cars would readily coast from the lower pit, and were drawn back by horses. The material was a glacial deposit, containing from 15 to 20% of large boulders, fully 50% of which had to be blasted. The cost of blasting is included in the record of cost given below. These boulders prevented the material from being classed as earth. Under most specifications for excavation, the material would have been classed as earth and loose rock. The cars were taken to the dump in trains, a brakeman being used on each train. Three to four horses working single, with METHODS AND COST WITH CARS 357 a driver, hauled the cars back to the cut. One man was also used on the dump, and he also attended to the track work. A 10-hr, day was worked and the following wages were paid: Laborers $1.40 to $1.65 Brakemen 1.75 Dumpman 1.75 Firemen 3.00 Drillers 1.65 Single horse and driver , 3.00 From 35 to 45 laborers were used on the work, from 3 to 6 drillers and 2 firemen. The firemen attended to the blasting. It was necessary to build a temporary trestle across a highway at a cost of $195. The following is the cost per cu. yd. for each item of the work compiled from the total cost: Loading cars $0.215 Temporary trestle across highway 0.015 Drillers 0.035 Explosives 0.010 Dumpmen and track work 0.023 Horses and drivers 0.045 Brakemen 0.022 Freight and hauling on outfit 0.025 Depreciation of plant (about 7%%) 0-015 Superintendence 0.015 Total per cu. yd $0.420 frn'i* I'M ; M'.'IU = '- ' : *.!i ,..-' . -.,< |, j. ,. ; .,-J; -'= Owing to the large number of boulders in this work, scrapers could not have been used in excavating the material* The boulders, too, were very hard on the cars; nevertheless the cars stood up well under the work. Owing to the down grade, the cars were much more economical in doing this work than either dump carts or wagons would have been. The track work cost about $80 for this job, thus making an average cost of 4 ct. per lin. ft., or $210 per mile, of track laid and taken up; but it must be remembered that no ties had to be laid, as it was an " industrial track " made in portable sections. It will be noticed that the cost of blasting was 4^ ct. per cu. yd. excavated, more than 75% of the cost being for the drill- ing. As there were only about 700 cu. yd. o* boulders blasted, the most per cu. yd. for blasting for the boulders actually blasted was 45 ct. The hauling of the material cost nearly 7 ct. per cu. yd. Taking into consideration the class of material excavated and the cost of blasting and the temporary trestle, the cost for the work is very reasonable. 358 HANDBOOK OF EARTH EXCAVATION Portable Railways in Road Construction. Engineering and Contracting, Mar. 4, 1914, gives 'the following: For roadwork portable track is laid along the side of the grade or along the shoulders, and extends from the railway siding, gravel pit, stone quarry or other source of supply to the places where work is being done. The equipment used on roadwork near Lockport, N. Y., con- sisted of about four miles of narrow-gage portable track, 40 (36-x24-in.) dump cars and two 5-ton dinkey locomotives. The cars were hauled in trains of 12 cars each, the arrangement being so made that there was always one train of loaded cars on the way to the site of the work, one train of empties returning for material and one train of cars being loaded. The average amount transported was 80 cu. yd per day. While hauling stone three miles from a crusher at the quarry to the road the cost of operating the trains was as follows: Fuel and oil for locomotives and cars $ 8.00 Labor : 2 enginemen at $2.75 5.50 2 brakemen at $1.75 3.50 1 track foreman at $3 3.00 1 track laborer at $1.75 1.75 Totals $21.75 Cost per cu. yd $0.272 As the material was hauled three miles the labor and fuel cost was 9 ct. per cu. yd. per mile. The average cost of grading the shoulder or berm of the road ready for track laying and laying track was between 2 and 3 ct. per foot of track. Cost with a Light Railway on Road Work. The Easton Car and Construction Co. of Easton, Pa., furnish the following data on 18 miles of road built for the state at Bremen, Ind. The cars used are standard 1^ yd. capacity rocker dump car. Trains consisted of from 15 to 21 cars which weigh 1,400 Ib. each when empty and hold 1% cu. yd. of wet gravel weighing 3,100 Ib. per yd. The average train is 20 cars or 60 tons on grades varying from level to 2% against the loads. The locomotive starts this load on a grade, as the grade is too long for a level start to do much good. Curves of 30 ft. radius are used, and the portable track is composed of 20-lb. rails on steel ties 3 ft. apart. This portable track is made in 15-ft. sections complete with steel ties and fish plates, so that a section may be easily handled by two men. One car in perhaps five or six is equipped with brakes on all four wheels, operated by means of standard brake mast and freight car type of hand wheel. The engineer on the job states that they make three round trips in a 9-hr, day, 7 METHODS AND COST WITH CARS 359 miles each way, or 42 miles, which is an average of about 5 miles per hr., including delays for loading, switching and all other causes. They fill the 300 gal. water tank after each trip, although this is not necessary. It takes them 4 min. to fill the tank by means of a syphon which is always attached to the lo- comotive. They also fill the coal bunker which holds approx- imately 400 Ib. after each trip, or three times each day ; the con- sumption of coal in 9 hr. is therefore 1,200 Ib. The cost of hauling per day of 10 hr.," the haul being 5 miles, is as follows: (Average speed including time for coaling, taking water and coupling, 5 miles per hr. Actual time 8 to 10 miles per hr.) Engineman $ 3.00 Helper for switching and coupling cars ! 2.00 Coal, y 2 ton at $4 2.00 Oil and waste .50 Laying and taking up track at $50 per mile x 5 miles = $250 (150 average working days per season ) 1.67 2 laborers on track 4.00 Interest and depreciation on outfit costing $12,000, at 20%, includ- ing repairs for one year based on 150 working days 16.00 Total per day worked $29.17 Eight-ton locomotive will haul 20 loaded cars or more per trip, averaging 30 yd. on grades up to 2%%, and make 5 round trips on 5 miles haul in 10 hr., or haul 150 cu. yd. per day, equal to 750 cu. yd. miles; cost per cu. yd. mile, 3.9 ct. Hauling Macadam Over a Portable Track in 111. According to Fred Tarrant, in Engineering News, Feb. 18, 1915, two 20-hp. locomotives, 6 miles of portable track, and 1.5-yd. steel dump cars were used in the construction of a 12.5-mile water-bound macadam road, 10 ft. wide, in Illinois. Rails and ties were made in 15-ft. sections, weighing 225 Ib. Two flat cars were used for hauling the track, but trains of dump cars coupled together with 6-ft. poles were better. A track crew of four men could lay an average of 2,000 ft. of track per day. In order to keep the track in good alignment one man was required continuously to watch and correct low joints and loose connections. i-v^-i By placing 10 to 12 cars ahead of the locomotive, and from 12 to 16 cars behind it depending upon the grade one lo- comotive could handle long trains. Where the grade was 4% or over, the engine dropped to the rear end of the train, and pushed the forward cars to the top of the hill, returning for the other half of the train later. Switching in the yard was handled by a mule. The equipment on one job was rented for 6 months, and in five months, 35,473 cu. yd. of broken stone 360 HANDBOOK OF EARTH EXCAVATION were handled, with an average haul of 3.17 miles, at a cost on the rental basis, including all the expenses and hauling both ways, of 14.8 ct. per ton-mile. This included also the neces- sary expenses for the equipment in first class shape. Team haul- ing on this job was estimated to cost at least 28 to 30 ct. a ton- mile. Hauling Macadam Over a Portable Track in Mich. R. P. Mason, in Engineering and Contracting, Apr. 7, 1915, gives the following : We had a very considerable stretch of macadam road to build and, in anticipation of a continuous program covering several years, a Koppel hauling outfit was purchased consisting of a 30-hp. locomotive, 50 cars, a tracklaying car and four miles of 24-in. gage portable track with curves and switches. This track is 20-lb. rail made up in 15-ft. sections with seven steel ties to the section. This unit is readily handled by two men. It is necessary to have track that is really portable and for this reason this type was selected. Owing to the very narrow gage a low center of gravity lo- eomotive is v6ry desirable and the selection of the above type with the water tank beneath proved to be wise, as it kept the rails on occasions when a less stable engine must have cap- sized. The cars have roller bearings and are extremely easy running. Our season's work was 9.5 miles of 16-ft. macadam 6 in. in depth compacted, laid in two courses, on what is known as the Manistique Trunk, or the road connecting Escanaba with Man- istique. We contracted for a sufficient supply of stone to keep the outfit busy to maximum capacity, to be delivered in hopper bot- tom cars; and I would say that this is a matter not to be over- looked, there must be a sufficient and constant supply of stone and, if shipped to the job, the railroad equipment must be in pro- portion and of proper and uniform type of cars to facilitate rapid unloading, or the efficiency of the work will suffer. The total output of a good sized quarry is required to keep this outfit busy and, as we have handled over 400 cu. yd. per day on short and medium haul, it is evident that no small crushing plant or undeveloped quarry would keep things going. A loader consisting of a 24-ft. belt elevator carrying 16-in. steel buckets, driven by a 6-hp. gas engine, carries the stone from a pit beneath the standard track into two small bins one for the large stone and one for screenings the stone being deflected into the proper bin by a hinged door. A powerful winch with steel cable, driven by the same engine, is used to spot the cars, METHODS AND COST WITH CARS 361 both standard and small. The pit mentioned is fitted with a slid- ing door to control the flow of stone to the belt. The capacity of this loader is about 600 cu. yd. per day. The portable track is laid under the bins with a siding to take care of the empty train. Suitable doors in the bins furnish the means of filling the train and the average time of filling a 25-car train is y 2 hr. Train was supposed to be always loaded and ready. Tracklaying is handled generally by three to four men and a car of steel is sent out as needed at the head end of the stone train, carrying 20 sections, or 300 ft. ^ of track. As our day's macadam work seldom exceeded one-eighth of a mile, two to three cars of steel per day were sufficient. The track is laid on the shoulder after the grade is complete and made 'as permanent as possible, for it is found that it pays to have the track well leveled and solid in order to make time with the train. At least one man was kept going over the track constantly, especially in wet weather, to keep it in shape. As fast as any considerable section of the road was finished the track was thrown to the center of the road, the metal thus giving a perfect roadbed for the long haul. The speed of the train was about 10 miles per hr., though that was not maintained as an average on account of a number of railway grade crossings where a watchman was stationed and where a short section of track had to be placed and re- moved for the passage of every train. Trains of 20 cars were hauled on the start and five cars were added later, making 25-car trains, and it is the intention to haul 30-car trains this season, as we find that the locomotive will easily handle that many on our ordinary grades. Cars were loaded with 1^4 cu. yd. which, when dumped at a standstill, just made one course of the large stone. The loaded train is always pushed in order to have the locomotive back of the dumped stone. The haul was about 3y 2 miles each way from the set-up; season's average nearly eight trains per day and 236 cu. yd. per day of stone. The spreading was done with a road machine hauled by two teams. When the cars were dumped there was .always some stone left in them, but as the machine cut close to the cars, after the second trip the remainder was removed with a rake in a moment and the train was free to pull out. The unloading did not con- sume to exceed 10 min. The road machine finished the spreading while the train was making another trip and a very little trimming with rakes left the road in perfect condition for rolling. 362 HANDBOOK OF EARTH EXCAVATION The crew required was about as follows: Loader 4 men Train 2 men, engincman and brakciutui Spreading 2 teams and teamsters Spreading 5 to 7 men Rolling 3 men Sprinkling 2 teams and teamsters Foreman 1 Watchmen 1 or more Tracklaying 4 Wages were $2 per day for laborers, $5 for teams with team- sters, $3 for rollermen, engineman, $90 per month. Compared with team haul the method described shows a saving of about 30 ct. per cu. yd., or nearly $700 per mile. We also save 39 ct. on our stone and 10 ct. on the unloading, making a total of about $1,800 per mile over previous prices. The saving on haul alone would be more marked on a longer haul. We also used the outfit in grading where material had to be moved some distance and found it extremely convenient and economical. Another very decided advantage of road building by this method is seen in the fact that there is no hauling over the road during construction and it is opened to traffic in perfect condition. It is also easier to keep the subgrade from being cut up and therefore takes less stone for a given thickness. The following costs include everything that is a proper charge to the work, the cost of moving outfit from one point to another, laying up, and tracklaying includes taking up as well. Load- ing includes setting up loader and in one case building a siding 1,000 ft. long. The number of watchmen makes the hauling cost high; a greater output will cut down the spreading and the overhead in this case is high on account of the short season. No. of days worked 93 Miles of finished stone 9.44 No. yards stone used 21,920 No. yards stone used per mile i . 2.310 No. days to build mile of road average 9.4 No. yards stone per day 236 Cost of tracklaying per mile of finished road $108.10 Cost per cu. yd. Cost of stone at our siding $0.860 Loading trains 052 Tracklaying 047 Engineer 020 Brakeman 013 Watchmen 017 Coal 012 Oil, grease and waste 002 Repairs 003 Total . $0.114 METHODS AND COST WITH CARS 363 Interest and depreciation on hauling outfit $0.052 Spreading 114 Sprinkling 043 Rolling 082 Foreman and timekeeper 030 Total $0.269 Interest and depreciation on all other machinery $0.040 General expense . . .031 Total $0.071 Total cost per yd. (loose) of finished road $1.418 Cost per mile $3,275.58 Hauling with Gasoline Mine Motors. The installation of three gasoline mine motors to replace mule haulage in the entries of the mines at Walden's Ridge, Tenn., as described by G. E. Syl- vester in Mines and Minerals, has displaced 23 mules and re- duced the cost of hauling by 49.1%. All the extra work in the mine entry necessary for the installation of these motors was some slight trimming to give ample clearance and going over the track to replace with 20-lb. rail the places on the entry where a lighter rail had been used. The following is an abstract of Mr. Sylvester's article as published in Engineering and Contract- ing, May 31, 1911: There was no difficulty found by reason of the many curves, as the motors have a 4-ft. wheel base and can take a curve of 25-ft. radius. The locomotives are 6 tons each and were built for the mine gage of 33 in. They are designed with 4-cylinder engines, of ample power to slip the wheels, and all parts are well protected, as is necessary for mine use. The mine cars used are about 1,400 Ib. in weight and carry 1.2 tons of coal. As the grade is in favor of the loads, the empty cars up the entry make the load for the motor. The regular 20-car trips are handled without difficulty, and on trial trips 40 cars have been taken up the entry. The comparative estimate of mule and motor haulage on one entry is as follows: COST OF COAL HAUL ON NO. 2 ENTRY, 1% MILES OR 3 MILES FOR ROUND TRIP 10 twenty car trips equals 224 tons By mules 4 drivers at $1.65 $ 6 60 9 mules at $0.50 4.50 Total by mules $11.10 364 HANDBOOK OF EARTH EXCAVATION By motor 1 motor-man, per day $2.05 '.. 1 coupler, per day 1.65 13 gal. gasoline at HVfe ct 1.50 2 Ib. carbide at 4 ct 08 % gal. gasoline engine oil at 23 ct 12 1 gal. transmission case oil 24 Total by motor $5.64 iving Or, 49.1%. These motors use 12 to 13 gal. of gasoline each per shift. The gasoline tanks, of which there are two on each motor, are so placed in the frame as to be well protected in case of derailment or accident. The tank can only be filled when detached from the motor, and in changing these tanks it is necessary to have the valve closed. There are two extra tanks with each motor and these are filled on the outside. When brought into the mine they are perfectly sealed until after being exchanged with empty tanks on the motor. There is therefore no handling of exposed gasoline in the mine. The motors are made by the Geo. D. Whitcomb Co. of Kochelle, 111. Cost of Mine Haulage by Electric Locomotives. Mr. W. F. Murray is the author of an article on mine haulage appearing in Engineering and Mining Journal and in Engineering and Con- tracting, Feb. 27, 1907. The following figures, abstracted from the latter account, show an actual comparison of cost of haulage by mules and by electric locomotives in a mine where 14 mules were replaced by one loco- motive. The output of the mine averaged 1,500 tons per day for 245 working days per year. The cars weigh 2,400 Ib. empty and hold 3,600 Ib., making a total loaded weight of 6,000 Ib.; 1,500 tons per day for 245 days makes a total of 367,500 tons yearly output. Cost of Mule Haulage. Mules cost $180 each and harness $25 per set. The investment cost for mule haulage is therefore as follows : 14 mules at $180 $2,520 14 sets of harness at $25 350 Total $2,870 Figuring annual depreciation at 20% and interest at 6% we have for interest and depreciation charges: Depreciation on $2,870 at 20% $574 Interest on $2,870 at 6% 172 Total $746 METHODS AND COST WITH CARS 365 It costs 50 ct. per mule per day for feeding, care and repairing harness. The wages of drivers are $2.80 per day. In addition, it is the custom in the West, where mule haulage is employed, to have a boss driver whose duties consist of directing the drivers to the different rooms, of seeing that the diggers have sufficient cars, etc. The boss driver's wages in this case were $85 per month. We have then: 14 mules 245 days at $0.50 $1,715 6 drivers 245 days at $2.80 4,116 1 boss driver 12 months at $85 1,020 Total $6,851 The total tonnage hauled being 367,500 tons, we have by divid- ing this sum into the above totals the following costs per ton hauled : Depreciation and interest on plant 0.20 ct. Labor and keep of mules 1.86 ct. Total per ton 2.06 ct. Cost of Electric Haulage. Compared with mule haulage the investment in " plant " for electric haulage is high. The fol- lowing are the figures: Engine, locomotive, boiler and generator $9,000 Switches, insulators and wire 1,200 Cost of erecting, etc 1,000 Total $11,200 The interest on investment and the cost of repairs and de- preciation are as follows: Interest on $11,200 at 6% $ 672 Depreciation on boilers, engines, etc., at 9% 810 Depreciation on switches, wires, etc., at 5% 110 Repairs on boilers, engines, etc., at 9% 810 Repairs on switches, wires, etc., at 5% 110 Total $2,512 The cost of labor and supplies are figured as follows: Engineman at $75 per month ..." '. $ 900.00 Fireman at $85 per month 1,020.00 Motorman at $2.80 per day 686.00 Nipper on motor at $1.50 per day 367.00 Oil and waste 100.00 Sand . 50.00 Total $3,123.50 The total is too small by the amount of the cost of coal re- quired to run the boilers. In reply to a letter calling the omis- 300 HANDBOOK OF EARTH EXCAVATION sion to Mr. Murray's attention, we are informed that the cost of the coal consumed must be charged to several items of work, such as pumps and fans, as well as to haulage, and that " after considering the cost of coal consumed the advantage is in favor of the locomotive." Taking the figures as they stand and di- viding 367,500 tons into the totals, we have the following costs per ton hauled : Depreciation, interest and repairs 0.68 ct. Labor and supplies 0.85 ct. Total 1.53 ct. Comparison of Costs. A comparison of the two methods of haulage on the basis of cost per ton hauled gives according to the above figures the following: Mule haulage, ct. per ton 2.06 Electric haulage, ct. per ton 1.53 Difference in favor of electricity 0.53 This difference would be somewhat less, it is to be noted, were the cost of fuel charged into the cost for electric haulage. In round figures, the saving by electric haulage in place of mule haulage is barely } ct. per ton, or for 367,500 tons a saving of $1,837 per year. In discussing these figures Mr. Murray says: " These estimates, taken from an actual case, show a consider- able difference in favor of electric haulage. The cost of installing mechanical haulage is greater than when a mine is supplied with mules; however, when we consider the cost of erecting a stable and the great loss due to mules killed in accidents, the initial expenditure is not so favorable to the use of mules. " The chief advantage in using mules lies in the fact that the mule can enter any portion of the mine unhindered, while the locomotive cannot leave the trolley. Another lact worthy of consideration is the difference in weight of the rails that may be used in each system; by mule power, steel as light as 16 Ib. can be used, while in other systems it is not advisable to lay less than 35-lb. rails. Also with locomotives an additional expense must be incurred, in bonding the rails. Central-Control, Electrical Car Haulage. Engineering and Con- tracting, May 18, 1910, gives the following: A considerable part of the clay excavated from the North Shore Drainage Canal, Chicago, will in time be used by the National Brick Co. for making brick. This company has the contract to remove the spoil banks for a part of the canal through the city of Evanston, 111., and also has a contract for excavating another part of the canal known as Section 8A. At present the work of METHODS AND COST WITH CARS 367 excavation is going on at a rate required by the brick company to obtain only as much clay as it uses for the manufacture of brick. After the canal is completed the company will concern itself with the removal of the spoil banks left on other sections. For the work of excavation proper, two 70-ton steam shovels are used and these are worked side by side in the cut and up against the dead end of the canal section. The distinctive feature of the plant is that the clay is hauled by motor-driven dump cars, moving in a continuous circuit and operated by a central-control electric haulage system. Car movements are controlled, except during dumping, by one man located in a tower in such a posi- tion as to command a general view of the work. This is one of the first applications of this system on contract work. It is claimed that the cost is not more than that of a haulage system of equal capacity equipped with locomotives (which latter would require at least three times the number of cars), while the cost of operation is materially lower than that for the locomotive haulage system. The equipment for this work consists of a power plant, 10 cars, and about a mile of narrow-gage track. The power plant consists of a 55-KW. generator belted to a 60-hp. engine. This plant supplies current for lights and for power. The current is carried on a third rail, of 12 Ib. section, which is placed in the center of the track. The tracks are of 30-lb. rail and 3-ft. gage. The cars are of 3 cu. yd. capacity and their weight, when empty, is about 4,400 Ib. Each car is equipped with a single motor of about 12 hp. capacity and with contact shoes taking current from the third rail. The motors are of special design, and each has in connection with it a solenoid brake which forms a part of the electric control system. The brakes and controlling mechanism are operated by current taken from the third rail at a reduc-.d voltage from that for normal propulsion. The track arrangement on which these cars are operated is merely a double track with a cross-over at each end. At the loading end the track ends in a 30-ft. stub lying between the steam shovels. The loaded cars pass from here for a short dis- tance on level grade, but in rising out of the canal cut the track is on a temporary trestle laid at a 12% grade. The tracks pass along the bank of the canal to the brickyard and up again onto a trestle, where they are dumped by hand. The novel feature of the haulage system is the control of all the cars by one man from a central point. The control of the cars consists of starting them from the shovel, bringing them up the incline and along the top of the canal bank to the dumping platform and starting them on their downward trip. In case of 368 HANDBOOK OF EARTH EXCAVATION emergency a car may be stopped or started on any portion of the track, but ordinarily the operation is continuous. Upon the down-grades the car is automatically governed as to speed, usu- ally requiring no attention from the operator. The car by its momentum, on down-grade, becomes its own motive power and the motor becomes a generator. The motors are series wound and it is only necessary to reverse the armature connection to make them act as generators. A certain amount of resistance is mounted upon the car and so adjusted as to form sufficient elec- trical load upon the motor, working as a generator, to hold the car to a certain calculated speed. This operation forms the "dynamic brake" and will never allow a car under any condi- tion to attain a greater speed on down-grade than this set speed. The conductor rail is divided into sections ( separated by insulated joints), each section having independent connection with the controlling apparatus at the tower, or control station. Thus the cars on each section can be controlled independently of those on any other section. With more than one car on a section, however, all these cars are controlled as a unit. It is the duty of the tower man to keep the shovels supplied with an empty car at all times and so to distribute the empty cars on their return to the shovels that there will be continuous operation without " bunching " the cars. The advantage of the operation of individual cars over that of trains is quite apparent. When one car is loaded it is not compelled to wait for the other cars to be loaded, as is the case where cars are hauled in trains. A car loaded at the shovel will be 1,000 ft. on its way before the next car is loaded. This makes^ it possible to keep all the cars working all the time and avoids keeping more than one car waiting for loading or un- loading at any one time. It is claimed that this system operates with only one-third of the cars required when trains are used. Another advantage is that these cars, on account of their light weight as compared to a dinky engine required for a train, do not require as heavy rails nor so much labor to keep tracks in condition and ballasted as is required where engines are used. The outlay for this equipment was about $28,000. During the first year the maintenance cost was abnormally high, due to the fact that no electrical man had been employed to look after the equipment. During the second year, however, a careful cost was kept on the maintenance and the cost given amounted to $505 for the entire year. The system used is the invention of Mr. F. E. Woodford, President Woodford Engineering Co., Chi- cago, 111. Cars Hauled by Cables. (Engineering News, May 21, 1903.) METHODS AND COST WITH CARS 369 On parts of the work of constructing the P. C., & W. R..R. in Ohio, the dump cars were hauled by cables from a hoisting engine. On one section four 3-yd. dump cars, weighing empty 2,500 Ib. each, were pulled by a cable from a hoisting engine on the bank above and ahead of the shovel. The cars coasted down to the dump by gravity and were hauled a short distance to the trestle by a team. Much time would have been saved had a double drum engine, two cables, two trains, and a switch been provided. On another section where the haul was 1,600 ft., one hoist was located above the shovel and the other one half way down the hill to the dump. Snubbing posts were used to guide the cable around curves. Two trains of 4 cars each kept the shovel busy, the waiting time which the loaded cars were being replaced by empties at the shovel being about 2 min. Fig. 10. Tramming System in Use at One of the Shale Pits of the Purington Brick Co. Tramming System Used in a Shale Pit. According to Engi- neering-Contracting, Mar., 1906, a highly economical tramming system for steam shovel work has been in use at Galesburg, 111., in one of the shale pits of the Purington Paving Brick Co. In this work the dinkey locomotive occupies a position inter- mediate between two trains of cars which deliver two ways to the bottom of two machines leading to the hoppers of the clay ma- chine at each end of the pit. The cars are of 2 cu. yd. capacity each, and the locomotive keeps 20 of these going, tramming them alternately in teams of six and four cars two ways to the ends of the pit, whence they are hauled, two at a time, to the hop- pers. When empty the cars run down by gravity and are switched automatically to the empty track. 370 HANDBOOK OF EARTH EXCAVATION Spotting Cars. A device shown in Fig. 1 1 is used to haul cars into position at the shovel. This consists of a long cylinder and piston into which exhaust steam is admitted. The amount of steam and time consumed in moving cars a short distance, from 5 to 7 ft., with this device is so small as to be negligible. Body of Steam Shovel Fig. 11. Device Used for Spotting Cars. Steam Shovel Work. A 90-ton Marion steam shovel, of 5 cu. yd. dipper capacity, but fitted with a 2 cu. yJ. capacity dipper was used. With this, digging from a 50 ft. bank an average of 17,422 cu. yd. of shale was handled per month of 26 9-hr, days, or 670 cu. yd. per day. It is estimated that this is less than one-half the amount that could be handled were the shovel digging loose gravel. As it is, the shovel is digging only one- third of the time. The material was delivered to twenty 2-cu. yd. cars, trammed two ways, 1,500 ft. and 2,000 ft. respectively, to bottom of two inclines, and then hoisted by cable to an elevation of 20 ft. above the track and dumped into the hoppers of the machines. The cost per month of 26 working days of 9 hr. each for the steam shovel work is shown in the following table: 1 engineman $110.00 1 crane man 85.00 1 fireman, 22 ct. per hr 52.65 3 track men (shovel), 17% ct. per hr 128.85 1 locomotive engineman 80.00 1 switchman, 20 ct. per hr 46.80 *2 hoistmen, 20 ct. per hr 93.60 39 tons coal, for shovel, $2 78.00 13 tons coal (locomotive), $2 26.00 26 tons coal (hoist), $2 52.00 Total per month , Hoistmen dump the cars. . . $752.90 METHODS AND COST WITH CARS 371 As 17,422 cu. yd. of shale were handled per month, the labor and fuel cost per cu. yd. was 4.3 ct. The charges for superin- tendence, oil, waste and incidentals are not included in the above estimate; adding these .the cost per cu. yd. amounts to practically 5 ct. A Cable Haulage Plant. In Engineering News, Jan. 21, 1904, is an article describing the plant of the Bronson Portland Cement Co. in detail. Fig. 12. Sketch Showing Track Arrangement at Mills. The marl used in the manufacture of the cement is dredged from under water by a dipper dredge, equipped with a 1^-yd. bucket and digging to depths of 30 ft. The dredge loads directly into cars. These cars were formerly drawn by horses but the increased capacity of the plant required a more rapid method of transportation. As the marsh was overlaid by a 2 to 5-ft. layer of unstable muck the use of heavy engines was impracticable, so a cable haulage system was installed. Fig. 13. Sketch Showing Manner of Carrying Haulage Rope Around Curves. The 1^-yd. steel dump cars are hauled in trains of ten or more, being " spotted " from the engine room in accordance with signals by rope and bell made by a trip rider. Fig. 12 shows the arrangement of the tracks and Fig. 13 the method used in carrying the haulage cable around the curve. The full width of the dredge cut is excavated on one side, the track being laid as the' cutting proceeds. Then the full width is 372 HANDBOOK OF EARTH EXCAVATION excavated on the other side. Finally, by means of a float or barge made of oil barrels to hold the empty cars, the space where the track was laid is excavated, taking all the territory an entire width of 175 ft. for each track. The hauling engine is a double 10- x 16-in. cylinder engine. The rails weigh 35 Ib. per yd. and are laid on 8-ft. cedar or tam- arack ties. The haulage cable is of %-in. plow steel, the haul rope being 5,500 ft. long, and the tail rope 1,100 ft. long. As may be seen, the track leads up a trestle inclined at a grade of 6.37 to the mill. At the top is a track large enough for 12 cars, descending at a 1% grade into the building. Alongside this is a side tr,ack for empties. The cars are drawn into the building by a separate tail rope cable. When the cars reach a point directly above the bins, the tail rope is quickly disen- gaged and immediately attached to the empty train, the short tail rope cable being attached at the same time. The haulage rope is likewise transferred, and the empties are pulled out without delay. The loaded cars are dumped by two men, and the cars washed out with a jet or hose. These cars after being dumped are hauled to the siding by passing the rear short cable around a sheave on the side track. The force required is as follows : Dredge, 3 men ; trip rider, 1 ; track cleaner, 1 ; dump-men, 2. An average of 1^ men in addi- tion is required for laying and removing track. Ten cars are loaded in from 6 to 10 min., and a round trip about 6 min. The output is about 30 cars or 50 cu. yd. per hr. More than 60,000 cars were delivered in 8 months. Life of Cable on an Engine Incline. The life of a %-in. wire cable used to haul cars on an incline operated in connection with steam shovels on the Chicago Main Drainage Canal was 150,000 cu. yd. of solid rock, cars being hauled 350 ft. horizontally and 60 ft. vertically. Details of the methods and cost of that work are given in Chapter XVI of Gillette's " Rock Excavation." Flat Car Unloaders. Flat cars are ordinarily unloaded with an unloading plow designed for the purpose. The car carrying the plow or scraper is attached to the rear of the " mud train " of 10 to 30 cars. One end of a 1^4-in. wire cable is hooked to the plow and the other end, which is attached to an ordinary car coupling link, is coupled to a car or to the engine. Usually this cable is 400 ft. long and extends -over 12 cars. The brakes on all these 12 cars are set tight, and the engine is started with the forward cars if there are more than 12 in the train. If the rear 12 cars are pulled along, blocks are laid on the track to hold them, or a few cars may be chained to the track. The engine moves ahead at a rate of 2 or 3 miles an hour, until the plow METHODS AND COST WITH CARS 373 has traveled the length of the 12 cars, and the material is thus scraped off the side of the cars. The engine is backed up a few feet, when 4 to G men throw the cable off to one side. Then the remaining full cars are backed up to the last half empty car where the plow is, the cable is coupled to the engine and the plow pulled forward as before. The plow is left on the last car which is unloaded by the next train. The time of unloading is 10 to 30 min., average 20 min., the engine doing as much in that time as 8 or 10 men would do in a day. When unloading on curves the time is longer, for snatch blocks must be used to keep the -cable on the cars. A snatch block Fig. 14. Side Unloader. Made by Marion Steam Shovel Co., Marion, Ohio. every third car is generally enough. The cable passes over the snatch block sheave, and the block is held with a chain passing over the side of the car, and fastened to the bolster or arch bar of the car. When the plow reaches a snatch block it must be stopped, the block and chain being removed and carried forward. Unloading this way takes about twice as long as on straight track. When much" material is to be handled on flat cars, two things should be done; (1) the cars should all be rigged with hinged sideboards that can be dropped down when unloading, for then a car will carry 14 cu. yd.; (2) and a hoisting engine should be rigged upon a car by itself for the purpose of pulling the plow 374 HANDBOOK OF EARTH EXCAVATION cable instead of using the locomotive for that purpose. A 10- x 12- in. double cylinder engine with a 1-in. cable for loose gravel, 1%-in. for heavier material, will unload a train of cars often in half the time taken by locomotives, since the cars need not be blocked or chained to the track, and there is little danger of breaking the cable as often happens where a locomotive pulls the plow, Furthermore, since this unloading engine on its car is a part of the " mud train," it can do the unloading while the whole train is moving ahead, and thus spread the material along a greater length of track. Fig. 15. Center Unloader. Made by Marion Steam Shovel Co., Marion, Ohio: After the material is unloaded by a plow alongside a track it can be most economically spread with a leveler or spreader. This spreader is a car provided with projecting side wings which can be raised by a winch when not in use. The spreader car is loaded with 5 to 15 tons of scrap to hold it to its work, and moves at 6 to 10 miles per hr., thus leveling off a ridge a mile long in 6 to 10 min. Ordinarily the spreading is done by the last train before the close of the day, but in freezing weather spreading must be done oftener. . Hauling and Unloading on the Panama Canal. In 1908, ac- cording to Engineering and Contracting, Aug. 26, 1908, the Pan- ama Canal Commission had 27 unloading plows in use. These were of the right hand, left hand, and center dump, types. Used in connection with them were 18 Lidgerwood unloaders. METHODS AND COST WITH OARS 375 From the Cule*bra Cut to the Tabervilla dump, trains of 17 cars were used to carry earth and rock. These trains were loaded under the shovel and carried directly to the dump without being made up a second time, the distance being 16 miles. On June 23, 54 of these trains were unloaded by four unloaders in 8 hr., handling a total of 17,280 cu. yd. This is at the rate of 4,320 cu. yd. per machine, being 540 cu. yd. handled per hr. for each machine. The canal commission used four styles and sizes of cars: The large Lidgerwood flats, 20-ycl. Western side dumps, 12-yd. Western and Oliver side dumps and the old French 6-yd. dump cars. The Culebra or Central division in order to reduce their loads to place measurement allowed the following loads per car: Lidgerwood flats, 20 cu. yd. 20-yd. Western dumps, 17 cu. yd. 12-yd. Western and Oliver dumps, 10 cu. yd. 6-yd. French dumps, 5 cu. yd. One train made up of 12-yd. Western dump cars hauling from Culebra to Mamei dump, nine miles, loaded, hauled and dumped 294 cars in 6 days, being 3,528 cu. yd. loose measurement or 2,940 cu. yd. place measurement. This meant 490 cu. yd. place measurement handled by this train a day. This was the highest record made by a train using these cars and running to this dump. With a train made up of 12 cars, this meant 4 round trips per day, or a distance of 72 miles traveled in 8 hr. by the train. The efficiency of the larger cars is shown by the fact that a train of 24-yd. flat cars, making a haul of 16 miles, carried to the dump 960 cu. yd. place measurement per day, as compared to 490 cu. yd. place measurement with 12-yd. cars on a nine mile haul. Methods of Handling TInloader Plow Cables. In The Rose Technic, Oct., 1903, Wm. S. Hawley has an article on grading railroads which contains a description of a method used for un- reeling an unloader plow cable. A Lidgerwood unloader engine operated the 1^-in. plow cable. This was long enough to stretch over 30 cars. To unreel the cable its end was attached to a chain stretched across the track between two piles. These two piles were driven about 14 ft. center to center, one on each side of the track, with their tops about 8 ft. above the rails. A short length of chain, the ends of which were hooked together when the cable was ready to be un- reeled, was fastened to each pile. After the cable had been fas- tened to the chains the train moved forward, thereby pulling it out. The cars held 12 cu. yd. each, and there were 15 cars in a 376 HANDBOOK OF EARTH EXCAVATION train. Eacli car had a wooden apron/ one end of which rested on the next car, thus forming a continuous floor over which the plow traveled. The material, after being dumped, was leveled by a spreader with air-operated wings. This machine leveled to a distance of 18 ft. from the center of the track. In Engineering Record, Feb. 17, 1900, the construction of the Jerome Park Reservoir is described. A 50-hp. engine operated a Lidgerwood plow used for unloading the cars. The train gener- ally consisted of a flat car carrying a Lidgerwood unloader en- gine, followed by an empty car at the front end, after which came 12 cars holding 120 tons of rock or earth, and finally at the rear end, a flat car carrying the plow. The train was drawn onto one of five parallel tracks which were spanned by a wire cable stretching between the tops of two 30-ft. posts guyed to deadmen. A second and parallel cable was stretched 5 ft. below the tops of the posts, and the two cables were connected by vertical ropes to the center of the track. Another short manila rope with a loop at its lower end was attached to each vertical tie. When the drum of rope on the car reached a point beneath the cable the end of the plow rope was hooked on to the manila rope, the train moved forward, and when the plow reached the same point, the cable was detached from the loop and at- tached to the plow. The plow was then drawn forward until it reached the empty car in the rear of the unloader. The 12 cars were unloaded by this method in about 5 min. Recommendations for Using Cars on Steam Shovel Work. En- gineering and Contracting, May 1, 1907, gives the following: In the report of the Committee on Roadway, of the American Railway Engineering and Maintenance of Way Association, the following questions were asked and answered. Hoiv many Pit- men f From three to eight are recommended; but under ordinary circumstances the committee recommends four men. Would it be advisable to have shovel made to swing back of the jack arm so that cars can be loaded in tunnel or rock work where entrance is narrow and cars cannot be pulled beyond shovel? Re- plies in favor, 13; against, 23. Form of Shovel Track. " T " rails on ties are mentioned by 12 members, chain rails are mentioned by 5 members, rails on stringers are mentioned by two members. The committe recom- mends " T " rails on ties. Length of Pieces for Ordinary Work. The replies vary from 3^ to 6 ft. The committee recommends 6 ft. What Form of Joint. The replies are as follows, viz.: Strap, 27; chair, 5; lap, 2; link and pin, 1; hasp, 1; U-bolt, 1. The committee recommends strap joints. METHODS AND COST WITH CARS 377 What Gage of Track for Dump Cars? Standard, 32; narrow, 3. The committee recommends standard. What style and capacity of cars, namely, dump cars, flat cars, cars with sides for plows and unloaders or other special forms, would you prefer for the following kinds of work? (1) Cut under 6 ft., haul less than one mile: Replies to circular letter all, except one, favor the ordinary Contractors' Dump Cars, with varying capacities. The committee recommends 6-cu. yd. dump cars. (2) Cut under 6 ft., haul one to six miles: 6 members favor 5-yd. dump cars, 2 members favor 12-yd. dump car, 3 mem- bers favor standard flat car, 9 members favor standard car, with permanent sides. The committee recommends standard car with permanent sides with swinging hinged doors and cars connected by aprons. (3) Cut under 6 ft., haul six miles or over: 7-yd. dump car is recommended by 5 members, 30-yd, dump car is rec- ommended by 1 member, standard flat car is recommended by 14 members, car with permanent sides is recommended by 10 members. The committee recommends same car as given in con- nection with (2). (4) Cut over 6 ft., haul not less than one mile: 9 members favor 5-yd. dump car, 3 members favor 12-yd. dump car, 1 member favors 15-yd. dump car, 9 members favor standard flat car, 10 members favor standard car with per- manent sides. The committee recommends 6-yd. dump car. (5) Cut over 6 ft., haul one to six miles: Replies received all, ex- cept one, favor either standard flat car or standard car with permanent sides. The committee recommends car described un- der ( 2 ) . Cut over 6 ft., haul over six miles : 8 replies favor dump cars varying from 5 yd. to 30 yd. capacity; 12 are in favor of standard flat car and 9 recommend standard car with permanent sides. The committee recommends car described under (2). The committee recognizes the fact that the standard com- mercial flat car must frequently be used, and when this is neces- sary, especial care should be taken to cover certain important matters : ( 1 ) See that the car is strong enough for the pur- pose. (2) Note that brake-wheels are in good condition, and in case material is to be plowed off", these must be placed at side of car. (3) Care should be taken that stake pockets are in good condition and not spaced too far apart. Four feet apart in center of car and closer at ends is considered good practice. (4) See that the stakes are strong enough to prevent accident or derailment of plow. Where dirt is dumped from trestle in fill for haul less than two miles, would you use light cars and light trestle or heavy cars and strong trestle? 15 replies favor light cars and trestles, 378 HANDBOOK OF EARTH EXCAVATION 12 replies favor heavy cars and trestles. The committee recom- mends light cars and light trestles. Has your experience with unloading plows, using cable, been satisfactory? 31 ayes, 6 noes. Would you handle cable by locomotive or an auxiliary engine and drum, and if the latter, give kind and size? 3 members recommend locomotive and 32 auxiliary engine. Sizes of drum vary from 3 ft. to 5 ft., two members recommending each 3 ft., 4 ft. and 5 ft. sizes, one member 3^ ft. and one other 4% ft. Engines are mentioned as 10x12 and 12x12, 60-ton and 25 hp. The committee recommends handling cable with an auxiliary engine and drum. The machine should be able to develop 60-ton pull and will weigh about 28 tons. Steam cylinders 12 x 12 in., and diameter of drum, 4} ft., which will permit four wraps of \y 2 cable to be made. When raising track do you prefer center plow for unloading or two side plows used alternately? 29 replies recommended center plow and 6 the use of side plows. The committee recom- mends that when raise is light, the center plow be used, but that side plows are more advantageous in making heavy fills. Has your experience with reversible plow been satisfactory? Ayes, 1; noes, 12. The committee does not favor its use. The Lloyd Unloading Machine. This device, described in En- gineering and Contracting, Oct. 2, 1007, is used for filling high embankments from dump cars. The general arrangement, Figs. 16 and 17, consists of a circular track at the head of the bank, around which the cars are operated by a cable and from which they are dumped. From the center of the unloader radiate large timbers which support the track, and which rest on iron rollers placed several feet apart and riding upon wooden sills on the top of the bank. At the center is a mast from the top of which steel rods support the ends of the radial timbers. Near the mast is a hoisting engine which operates the cable for haul- ing the cars. After the train has been uncoupled from the loco- motive and hitched to the cable it is pulled around the track and dumped while in motion. Material can be dumped at any point either inside or outside making it possible to fill from 40 to 70 ft. wide. The unloader is moved forward by its own power, 10 ft. at a time. The force required consists of engineer, carpenter, and 3 laborers. The advantages of this machine on high fills are: ( 1 ) The dispatch with which it handles trains ; (2) Low cost of construction as compared to cost of trestle; (3) Ease of erecting and dismantling. METHODS AND COST WITH OAKS 379 Fig. 17. General View of Continuous Car Unloader. Fig. 16. Plan of Continuous Car Unloader. 380 HANDBOOK OF EARTH EXCAVATION The cost of the machine including the hoisting engine is about $5,500. These machines have been used by E. B. and A. L. Stone Co., Contractors, Oakland, Cal. A Swinging Platform Dump Track. The device for making a wide fill was used at a mine in Colorado. A platform was Fig. 18. Plan and Elevation of Swinging Dump Track. pivoted to swing laterally so that a dump 57 ft. wide could be built without shifting the main track. Two men moved cars to and from the dump by hand, and dumped them at the rate of 100 per day. The swinging truck was composed of 2 pieces of 8 x Fig. 19. Details of Turntable and Truck^ 16-in. x 32-ft. pine upon which was laid a platform of 3-in. planks carrying the rails. The rear end was supported on a 4-wheel truck upon which it pivoted; the outer end was supported upon wheels travelling upon a rail of 22-ft. radius leaving a 5-ft. overhang. End dump cars were used. METHODS AND COST WITH CARS 381 Comparative Cost of Handling Earth on Flat and Dump Cars. According to Itaihvay Age (Jasette, June 18, 1915, the cost of handling earth on flat cars was 100% greater than the cost of handling it on dump cars, in work on the new passenger terminal and belt line at Kansas City. Over 2,000,000 cu. yd. of earth and rock were removed and handled on flat cars and on 12-yd. Western air dump cars. For two months the cost of handling material with these two types of equipments was kept in two files. The material during these two months consisted of approx- imately 75% solid rock. The flat cars were wooden construction, capacities of 60,000 Ib. and 80,000 lb., and had been in constant service of 18 months at the time this information was collected. In justice to them, it should be said that the repairs increased the average cost by approximately 1.5 ct. per cu. yd. The dump cars were of steel frame construction; of 80,000 lb. capacity, and had been in service 5 months. The cost of engine service includes the rental of the engines and the pay of the fuel, from the time of their arrival to the time of their departure of the trains at the dump. One great advantage of the dump cars over the flat cars was that it was found possible to unload at the end of a spur track on the fill successfully, with the dump cars; while this could not be done with the flat cars and unloader plow, because the plow at the end of the train occupied a space of at least 20 ft. Fur- thermore, it was impossible to do little loading on the main COST OF HANDLING MATERIAL ON FLAT AND DUMP CARS FOR TWO MONTHS First Month Flats Dumps Car repairs $.071 $.001 Engines 082 .024 Lidgerwood and airman 005 .007 Labor on cars 027 .009 Labor on truck 084 .066 Engineering and superintending 004 .004 Miscellaneous 010 .003 Total $0.282 $0.114 Second Month Flats Dumps Car repairs $.070 $.007 Engines 075 .024 Lidgerwood and airman 004 .008 Labor on cars 034 .008 Labor on track 093 .057 Engineering and superintending 004 .005 Miscellaneous 006 -004 Total . .... $0.286 $0.113 382 HANDBOOK OF EARTH EXCAVATION track by means of this unloader and plow, because of the danger of delay of construction trains and traffic. On the other hand, trains of dump cars were frequently sent out to unload a few min- utes ahead of passenger trains, with only slight danger of de- laying them. Dumping Cars with Derricks. (Engineering News, Aug. 24, 1905.) This method was devised by W. J. Newman. The spoil from the Chicago tunnel was delivered in 4-cu. yd. capacity cars, mounted on 24-in. gage trucks, by electric locomotives to the dump at Grant Park. Small 4-wheel dinkeys hauled the cars to a 75-ton derrick of 40 tons capacity, with a 65-ft. boom. The bottoms of the cars were so arranged that when released they fell clear away from the sides, thus presenting no obstacle to the dropping of the sticky clay. A car body was lifted by the derrick, dumped, and placed back on its underframe. Very high dumps could be made. Removing Sticky Material from Dump Cars. Engineering and Contracting, Sept. 25, 1907, gives the following: In excavating for a foundation at New York City part of the spoil was dumped into seagoing scows. The spoil was conveyed to the dock in 3-yd. wooden side-dump cars and loaded by means of a stiff-leg derrick with 60-ft. boom seated in the edge of the dock. The pivots on the car trucks were removed and the car bodies were used as skips, being lifted over the scows by four chains attached to their corners. The excavated material was sticky and tenacious and some diffi- culty was encountered in getting the cars to dump clean. This trouble was done away in the following manner: The original dumping arrangement of the cars consisted of one long side hinged by bars from each end pivoted in the centers of the end walls and operated by hand levers. These levers were removed and the lower edges of the hinged sides provided with latches to lock them shut and with rings engaging the hooks of two of the hoisting chains. In dumping, the boxes are lifted from the cars and set on the deck of the scow, the chains slackened and the latches opened. When the hoist is again operated the chains first open up the revolving side and then lift the box, revolving it until the open side is down and all the contents are discharged. A Method of Unloading Cars to Bins in a Small Space. En- gineering and Contracting, May 3, 1911, gives the following: Fig. 20 illustrates a hoisting tower located over the material track adjacent to bins. A clamshell bucket is operated in the hoisting tower to raise the material from gondola cars to a point in the tower above a swinging chute. The chute is automatically swung under the bucket so that the discharged load falls from "' " METHODS AND COST WITH CARS 38 the bucket to the swinging chute and from there is guided to its proper compartment in the bins. The former method for loading the bins was by means of a bucket conveyor which carried the material from a pit below street level. The material was dumped into the pit through a grating from wagons. This method would have been possible at the present location of the plant if bottom dump cars could Fig. 20. Arrangement for Unloading Cars into Bins. have been secured, but as this could not be guaranteed the new device was gotten up. From 8 to 10 cars are unloaded per 8-hr, day, allowing for time lost for switching and moving the cars for the clamshell. Three men are used in the car to locate the bucket and an en- gineer and fireman are required to operate the double drum engine and boiler. The cost of the labor is estimated as follows: 384 HANDBOOK OF EARTH EXCAVATION 3 laborers at 37% ct. per hr $ 9.00 1 engineer at 75 ct. per hr 6.00 1 fireman at 37% ct. per hr , . 3.00 Total per day $18.00 300 yd. average per day, per yd $ 0.06 The plant and methods were worked out by Mr. J. K. Thomp- son, who is superintendent for the contractors. Unloading Cars by Sluicing. J. C. Lathrop, in Engineering News, Sept. 25, 1913, describes a method of unloading cars of sand, gravel, and cinders, employed by him in the construction of a fill near Akron, Ohio. By means of water pumped by a 20-hp. motor-driven pump from a canal, 400 or 500 ft. away, the material was sluiced from hopper-bottom cars to any point within 150 ft. A 4-in. pipe line, with suitable valves, and 100 ft. of 2^-in. hose was used. The best method was to fill a car with water, then open the bottom gates, and, with a jet from the hose, wash the material into galvanized iron chutes leading from a point beneath the car to the place of deposit. Two men could unload a car 40 cu. yd. of sand or loam in 2 hr., and of cinders in 3 to 4 hr. One decided advantage gained by the sluicing method was solidity of fill. The comparative cost of unloading cars by water jet and by hand was: Unloading 10,000 cu. yd. (250 cars) by water jet: 1,000 hr. labor at 20 ct $200 Labor installing and removing pipe electrical connections, pump and motor 225 Depreciation of plant (assumed) 100 Current, 1,000 hp.-hr. at 2 ct 20 Total at 5.45 ct. per cu. yd 545 Unloading and spreading 10,000 cu. yd. by shovels and scrapers: 5,000 hr. labor at 20 ct $1,000 1,600 hr. team and driver at 60 ct Total at 19.6 ct. per cu. yd $1,960 Spreaders. Spreaders pushed by a locomotive are often, used in connection with car unloading plows. Fig. 21 shows a spreader, made by the O. F. Jordan Company of Chicago. A ditching device for use with this spreader is, shown in Fig. 22. It is claimed that this can be operated at the rate of 8 to 12 miles per hr. in shallow cuts and that two or three trips through the cut are sufficient to form the ditch. In deep cuts the material is forced into a pocket back of the plowing edge METHODS AND COST WITH CARS 385 which holds 6 to 10 cu. yd. The material is wasted at the end of the cut er on a fill. Cost of Spreading with a Jordan Spreader. Mr. S. T. Neeley in Engineering News, August 9, 1906, gives the cost of spread- ing material dumped from 12-yd. Western dump cars. The Jordan Spreader at Work. spreader cost $2,400, and the engine, which was only partly em- ployed in this work, cost $2,200. The daily cost per working day was as follows: Interest and renewals $2.00 Engine runner and fireman 5.50 2 laborers at $2.25 4.50 Fuel, etc 5.75 Total per day $17.75 The cost per rainy day and holiday was $8.50, giving a total cost per month of $440, or a cost of 1.4 ct. per cu. yd. for 30,800 cu. yd. Engineering and Contracting, July 24, 1912, in an article on four-tracking the New York Central and Hudson River R. R., gives some data on using a Jordan spreader. On this work dump- ing was done from the main track until the embankment to hold a construction track had been built. The traffic was very heavy on this road, so no more material was dumped from the main line than was absolutely necessary. Train loads of 150 to 200 cu. yd. were dumped and spread (using a narrow wing on the spreader), in 6 to 8 min. When from 12 to 15 min. were avail- able the large wing was used, and the earth was spread to the full working depth of the spreader. If the spreader is taken care of it should be sold at the end of 15 years for a reasonable price. 386 HANDBOOK OF EARTH EXCAVATION The machine can easily handle all material which can be sup- plied by trains which might be anywhere from 1,000 to 20,000 yd. per day. The first cost of the spreader was $5,000. _ Fig. 22. Ditching Attachment for Jordan Spreader. Bibliography. " Handbook of Construction Plant," Richard T. Dana. " Electricity and Haulage," Francis A. Pocock, Trans. Am. Inst. M. E., Vol. 18, p. 412. " Wire Rope Haulage and Its Application to Mining," Frank C. Roberts, Trans. Am. Inst. M. E., Vol. 16, p. 213. " Notes on Compressed Air Haulage," J. H. Bowden, Trans. Am. Inst. M. E., Vol. 30, p. 566. " The First St. Tunnel at Washington," Eng. Rec., Sept, 3, 1904. " Methods and Costs of Operating Automatic Railways for the Storage of Materials in Bulk," Eugene Michel, Eng. and Con., May 15, 1912. CHAPTER XI METHODS AND COSTS WITH STEAM AND ELECTRIC SHOVELS Types of Shovels. There are so many different designs of power shovels in use that it is extremely difficult to make a complete classification. For the purpose of study of costs the following classification seems sufficient. 1. Non-Revolving Shovels. a. Standard Railroad Shovel. b. Traction Shovels mounted on broad-tired wheels or cat- erpillar treads, or on " feet " as in the so called walking dredge. 2. Revolving Shovels. a. Heavy Stripping Shovels carried on two parallel tracks. b. Standard gage Railroad Revolving Shovels including the so called Railroad Ditchers. c. Small Revolving Shovels mounted on wheels, skids or caterpillar treads. 3. Miscellaneous Excavating Tools of the Shovel Type. How to Handle a Steam Shovel Plant. Mr. E. A. Hermann's excellent monograph on this subject is now out of print, but we are indebted to his work for some of the following suggestions. Fig. 1. Side View of Steam Shovel. tm *;!"., fw-i-.fi: '..usxjsj Figs. 1 and 2 show the general features of the types of ma- chines designed to run on tracks. It will be noted in Fig. 2 that jacks are used at the sides to brace the machine. A revolving shovel can dispense with these jacks. Operation of Steam Shovels. All movements of the dipper are usually controlled by two men, the cranesman and the engine- man. The engineman operates the levers that cause the raising or lowering of the dipper and the swinging it right or left. The 387 388 HANDBOOK OF EARTH EXCAVATION cranesman regulates the depth of cut made by the dipper, releases it from the bank when full, and trips the latch of the bottom door when ready to dump the bucket. These two men must learn to work in perfect unison, for the output of the shovel depends very largely upon , their combined skill. After dumping, the bottom door latches by its own weight when the bucket is swung down and back ready for the next scoop. In loose gravel a bucketful can be loaded every % to % min., in hard materials, 1.5 to 2 min., but one would make a grievous blunder were he to figure the daily capacity of a shovel on any such basis, for there are always delays in moving the shovel forward and placing the jacks which has to be done about every 4 or 5 ft., delays in " spotting " cars ready for loading, etc. The laying of a new Fig. 2. Front View of Steam Shovel. section of track, moving the shovel forward 4 ft. by its own power, and jacking up will ordinarily consume 3 or 4 min. The width of the cut or swath excavated by a shovel varies from 18 ft. for the smaller shovels to 120 ft. for the larger ones. The depth of a cut depends largely upon the material; easy running sand or gravel might be worked almost to any depth; sidehill cuts in loose gravel up to 300 ft. in height have been taken. There is danger in such cases of a slip that will bury the shovel. Cuts 60 ft. deep are common in gravel pits. In average material cuts of 25 to 30 ft. are common, while in hard tenacious material the cut should not be deeper than the height to which the dipper can be raised that is, 14 to 20 ft. Where cuts are very shallow the ordinary steam shovel cannot work economically at all, although the small revolving shovels seem better adapted to shallow cuts than any of the others. Beside the cranesman and the engineman there are usually a . COSTS WITH STEAM AND ELECTRIC SHOVELS 389 fireman, a blacksmith, a blacksmith's helper, two to five car repairers, and four to ten laborers. In average soil four laborers are enough, but in tough material that must be broken down by wedging or blasting ten and sometimes more are needed. For breaking down the bank in front of the shovel the men are provided with a 16-ft. hickory or ash pole, shod with a pointed spike. The blacksmith and helpers are provided with a portable shop, forge, etc.; their principal work consisting in repairing side boards, chains, etc., on the cars. Higher Cost in Shallow Cuts. The reason for the increased cost in shallow cuts is quite apparent if one stops to " figure," but in deepening the Erie Canal, for example, where the cut was only 1 to 2 ft. deep, we have seen steam shovels used by con- tractors who evidently had not stopped to " figure " beforehand they did their " figuring " afterward, to their sorrow. If a shovel could excavate a block 18 ft. wide by 2 ft. deep by 4 ft. forward, each move, it would excavate less than 3 cu. yd. before a move would be necessary. Obviously the bucket would go out about half full each scoop, but even assuming that it were full, and held 1 cu. yd., we see that more than half the shovel time would be spent in moving forward. If the shovel load were ^ cu. yd., which is higher than the average in such a shallow cut, the shovel would be doing useful work about 2.5 hr. out of the 10. Widening Railway Cuts. This is a class of work for which steam shovels are so often used that we shall consider the methods of attack in some detail. Before the shovel can begin work it is generally necessary to excavate a section of the cut, AB, Fig. 3, 30 to 50 ft. long, using wheelbarrows, scrapers or the like. The switch AB is laid off the main track for the shovel to travel upon, and the " mud train," of 10 to 20 flat cars, is drawn up on the main track ready to be loaded. The shovel is moved forward as soon as all the material within reach has been loaded, and to do this short sec- tions of track 4 to 6 ft. long are provided. These sections are usually moved by attaching them to the dipper with a chain, and dragging them from the rear to the front. When the shovel has moved forward the length of a full rail, 30 ft., rails are laid to extend the switch so as to keep it close to the shovel. This is particularly desirable where the bank is apt to cave, for then the shovel can be moved back if caving is anticipated. Since railway hauls are usually long it seldom pays to have less than two locomotives with trains, and unless automatic dump cars are used two trains will be found economic even on short HANDBOOK OF EARTH EXCAVATION hauls of ^ mile or so. This, however, is a matter that the con- tractor or engineer may quickly determine by a little observation in each particular case. Three engines and crews will be needed for hauls of more than 10 miles, or where the traffic on the main line is so great as to cause many delays in moving the " mud train." A contractor in estimating the cost of widening railway cuts must be careful to allow liberally for delays due to traffic on .ifS^X^' MS J ; H- '^'HF 1 / j -J K :. ^ Fig. 3. Shovel Widening Cut. hfH,':-,r ):,*>,.,] <::;; Yi,fj,,ivJO the main line, which may be 40 to 70% of the working 10-hr. day. As shown in Fig. 2, the track on which the shovel runs should be a foot or two lower than the main track, not only to provide for material that drops off the cars and that washes in from the sides of the cut, but also to drain the ballast on the main track. Where the traffic delays do not exceed 5 hr. out of the 10 _ . Fig. 4. Arrangement of Tracks. . ' working hours it is generally considered more economic to work as just described, but when the delays become more frequent, another method must be employed. A narrow cut is first made by hand shoveling so that a switch track for the "mud train" may be laid, Fig. 4. In doing this hand excavation, flat cars are often loaded by men with wheelbarrows, but this method is slow since only a very small COSTS WITH STEAM AND ELECTRIC SHOVELS 39 1 gang of men, 6 to 10, can be worked at the face of the cut. Three to six flat cars are run out on the side switch, and a plank run- way laid on the end car nearest the face of the work. The inert load the car farthest from the face first. The author would sug- gest that a " locomotive crane " or traveling derrick moving back and forth on the main track could be used to excellent advantage instead of wheelbarrows for work of this character; and in soft material, if provided with a clam-shell bucket, such a traveling derrick could be operated with very little hand shoveling at all. Upon the approach of a train, the traveling derrick can rapidly move to the side switch back of the mud train. Instead of flat cars, contractors' dump cars may be used and drawn away by horses to the dump, or one-horse dump-carts may be used. The work is too confined for scrapers to be used. After the narrow cut has been made, the side track is laid and the steam shovel run in on a second switch shown in Fig. 4. Cutting Down Railway Grades. It often becomes necessary to cut down railway grades at summits, when methods of attack differing from the foregoing must be adopted. Fig. 5 shows the most common method of attack where the mud train is on the main track. It will be noted in Fig. 5 that the steam shovel track is on blocking, the grade of its track being about 2 ft. below that of the main track which is about as low as a small shovel can work and dump into the cars. The blocking is made of 6- x 12-in. x 4-ft. sticks upon which 12- x 12-in. track stringers are laid, and the track is kept level. This blocking is generally 5 ft. high, for a small shovel can usually dig only 5 ft. below the track it runs upon; thus it will be seen that the depth of each slice or cut is only 5 + 2 7 ft.; and, as shown in Fig. 5, the suc- cessive cuts are parallel with the old main track grade until the last cut is made to final grade. This shallow cutting and block- ing up of the shovel track make the work somewhat more ex- pensive than ordinary. The engineer in fixing a new grade should have in mind the fact that it is cheaper to make an even number of full cuts of say 7 ft. each than to plan so that a fractional part of a full cut must be made. Some shovels cut fully 8 ft. below their track instead of 5 ft. r and for extensive work of this kind are evidently far more eca- nomic. Figs. 6, 7 and 8 show various cross-sections of cuts. It should be noted that a steam shovel cuts a 1 to 1 slope,, whereas the finished side slopes must often be 1.5 to 1. In that case the shovel can either undercut, as in Fig. 7, or it can supercut, as in Fig. 8. Undercutting is the most economic for no more material is moved than is necessary; and the rains will, 392 HAND-BOOK OF EARTH EXCAVATION COSTS WITH STEAM AND ELECTRIC SHOVELS 393 slough off the upper part of the cut until the desired permanent side slope is obtained. But if the work is super-cut, the slopes must be trimmed by hand, which is an expensive method. Where traffic is very heavy a temporary side track must first be built, as described under Widening Cuts. Fig. 9 shows such a Fig. 6. Cross Section of Cut. v ^v r*F--j"" Fig. 7. Cross Section of Cut; Shovel Undercutting. Fig. 8. Cross Section of Cut; Shovel Super-Cutting. ^TT Tract Fig. 9. Cross Section of Cut. Using Temporary Main Track. temporary track at A. If the depth of the original cut exceeds the height to which the dipper can be raised, and if the material is so tenacious that it cannot be broken down by the men with bars, then cuts are made as in Fig. 10, where L L are the tempo- rary loading tracks. 394 HANDBOOK OF EARTH EXCAVATION On double track railways the traffic may be diverted to one of the tracks while the other is used for the " mud train." It will be seen that each cut must be studied as a separate problem, the object being to secure the necessary deepening with the fewest possible number of " swaths " or cuts. Railway Construction Work. Where an entirely new cut is to be taken out, the work may be attacked in a way somewhat different from the widening or deepening of existing cuts. There are two methods of attacking a new cut: (1) The through-cut Fig. 10. Using Temporary Track in a Deep Cut. method; or (2) the side-cut method. The work that we have just been describing comes under the side-cut method ; that is, the cars are loaded upon a track laid alongside of the shovel and in advance of it. The through-cut method is shown in Fig. 11, from which it will be seen that the loading tracks are carried through at the same time with the shovel track. One of the loading tracks S 1 , is often dispensed with, although the work is Fig. 11. Through Cut Method on New Construction. greatly facilitated by having two cars, B and BI, always on hand to be loaded. In through-cut work only contractors' dump cars can t>e used, since it is obvious that a flat car could not be run up far enough to be loaded. Moreover, the frequent moving of the cross-over tracks, C and Ci, makes it important that the track be a light one. The great objection to the side-cut method is that the grade of the natural ground is generally so steep that a side-track can- not be laid over which a locomotive can travel, and to get a side- track through the shovel often has to do a lot of dead work, COSTS WITH STEAM AND ELECTRIC SHOVELS 395 as shown in Fig. 12, where the shovel is shown in the act of cutting down the top of the hill so as to make a trackway for the loading track. Wheel scrapers, or the like, can in many cases be used in such a case, and the material may be wasted off to one side or put in the fill, if the haul is short. Where a track can be laid at once on the natural ground, or where such cutting as is shown in Fig. 12 is small, the side-cut method is of course to be preferred since the cars are more quickly " spotted," that is, placed alongside the shovel ready to be loaded. Where the through-cut method is used, as in Fig. 11, either a team of horses is used to spot the cars, or a light 4-hp. hoisting engine with cable may be used, the engine being generally sta- tioned on the bluff in front of the shovel. Some contractors Fig. 12. Side-Cut Method on New Construction. ";TJ,Iir^S^ use an extra locomotive for spotting the cars, and upon the whole that is the best method. If the steam shovel used is of the traction type, weighing about 35 tons, it can readily climb the summit of most hills that are to be cut down, and attack the work there by the side-cut method, providing the cars can be moved over their track. A dinkey loco- motive will climb a 10% grade with 4 empty cars, so that if the grades are greater, the only methods remaining are to load into wagons, or to use a hoisting engine to pull the empty cars up and let the full ones down to the dump. By providing snubbing posts against which the wire cable rubs, such a cable may be used for long distances (1,000 ft.) even on curves; and by using a second hoisting engine to take the cars when the first reaches the " end of its string," distances up to nearly half a mile may be covered. Where cables are used in this way on the side-cut method, a train of 4 to 6 cars is usually operated, and the track must be laid on a grade of at least 1.5 to 2% to insure that the cars will start and run down by gravity. Each train of cars is pulled up past the shovel, and the last car loaded first; then the hoisting engineman slacks on his brake and 396 HANDBOOK OF EARTH EXCAVATION lets the cars " down a notch," so that the next one can be loaded. There is always some lost time in dropping the loaded cars out of the way and getting up a train of empties, even where a double- drum engine is used, but the shovel can be moved forward during this interval and so reduce the lost time. The cable method is not as economic as the use of contractors' locomotives, and is not used where it can be avoided. Canal Excavation. We come now to a class of work that usu- ally differs considerably from railway excavation. In modern canal work the material taken from cuts is not used to make fills, but is wasted. This generally makes an entirely different method of attack necessary, for while the upper part of the excavation can be taken out by the side-cut method, as the excavation in- found Houst CHANNEL & c t f o m Fig. 13. Arrangement of Track on Chicago Drainage Canal Work. creases in depth a time is reached when locomotives cannot climb the grades necessary to get out of the canal prism to the waste dumps. Since the shovels do not have to make frequent moves from hill to hill as in railway work, a larger type of shovel can be used; but there is no gain in using larger shovels unless large cars can be delivered rapidly enough to keep the shovel busy, or unless the material when blasted breaks up in such large chunks that a small shovel cannot handle it at all. Figs. 13 and 14 show arrangement of track on two sections of the Chicago Drainage Canal work. Cars were handled with con- tractors' locomotives. Both these examples illustrate the use of the side-cut method of excavating the upper part of a canal section. When the depth of the cut reaches a point where the locomo- COSTS WITH STEAM AND ELECTRIC SHOVELS 397 tives cannot move the trains up the incline, it becomes necessary to install a hoisting engine plant, using a cable to pull cars up the incline. The cars may be loaded by the side-cut method as before, and run to*the foot of the incline either by locomotives or by teams of horses, and there hoisted by the engine. At the top of the incline, either horses or a locomotive may be used to haul to the dump. Since the hoisting engine must be moved when the haul to the shovel becomes very long, the hoisting engine may be mounted on a platform car 18x40 ft., running on a very wide gage track. A 13 x 16-in. double-drum engine has handled 2,500 cu. yd. per Fig. 14. Another Arrangement of Track, Chicago Drainage Canal. 10-hr, day on one of these inclines. As such a plant costs only $3,000, and is very flexible, being easily adapted to any particular kind of work, it is evidently meritorious. Where an incline serves only one shovel, instead of two, a much smaller engine will evi- dently serve. Fig. 15 shows the asrangement of tracks for use with such an incline. It will be noted that the tracks on the dump are so arranged that the loaded cars can be run on track A, so as to pass the empty cars returning on track B. By using locomotives instead of horses to handle the cars it would not be necessary to move the incline often, unless it were to keep down the investment in rails and ties. D. J. Hauer, in Engineering News, Dec. 31, 1903, calls attention to the fact that through cuts and grade reductions work are more expensive with a steam shovel than widening cuts, the first class of work mentioned being the most expensive of the three. For 398 HANDBOOK OF EARTH EXCAVATION through cuts, especially where they are small, requiring frequent moving, a 35- to 45-ton shovel is to be preferred, as it is more easily moved and its 1 to 1% dipper will fill cars as fast as they can be shifted. But 65- to 95-ton shovels are better on grade Fig. 15. Tracks Used with an Incline. reductions and double tracking, because they can be moved on the existing track. They can be easily supplied with coal and water and more readily served with cars. Fig. 16. Cross Section of Steam Shovel Excavation (Solid Lines Show Intended Final Cross Section; Dotted Lines Show Section Actually Cut by Shovel). S. T. Neely, in Engineering News, Aug. 9, 1906, describes a job where a 65-ton Bucyrus shovel, loading 12-yd. Western dump cars, took out the first cut to a depth of 9 ft. below the top of rail of loading track as shown in Fig. 16, COSTS WITH STEAM AND ELECTRIC SHOVELS 300 Attention is called to the fact that such a deep excavation is too deep for the fastest work, and that the first cut was so large as to require excess excavation in the remaining cuts. A program of excavation is suggested in Fig. 17 which would obviously have been more economical. Fig. 17. A Better Method of Excavating Cut Shown in Fig. 16. Making a Steam Shovel Cut of Two Lifts in One. This is de- scribed in Engineering and Contracting, Mar. 2, 1010, by H. Mor- ton Stephens. The work on which this was done was in North Carolina on the Southern TCy. The outfit used consisted of two model 60 Marion shovels, seven dinkeys, cars, rails, etc. The shovels were started at opposite ends of the work, one of them being moved a distance of miles in 10 days over dirt roads. The first two cuts taken out by one shovel contained about 52,000 CD. yd. and were taken out in the usual 8 ft. lift manner. The specifications of the railroad company called for a 20-ft. roadbed and 1 to 1 slopes in cuts, and would not allow the contractor for the additional width made necessary by the use of a model 60 shovel, which requires, when using a dinkey track in the bottom of the cut on the last lift, a 26-ft. roadbed. As the remaining six miles allotted to this shovel were all practically two-lift cuts, averaging about 13 ft. in depth, and as some of the cuts were about 3,000 ft. long, it was apparent that some scheme had to be devised whereby this extra unpaid for material would not have to be moved. Upon investigation it was found possible to raise the boom on the shovel by simply taking out the links or loops in the boom support guy rods or hog rods, at the end where they are attached to the yoke at the apex of the A-frame. It was also found neces- sary to make two plates to fit on the rim of the swinging circle, at the corners of the aperture in the same under the boom, in order to reduce the angle and prevent the cutting of the cable 400 HANDBOOK OF EARTH EXCAVATION which operates the swinging circle. This raising of the boom, etc. was accomplished in about two hours. The shovel then started in on a single track cut about 3,000 ft. long, with an average depth of 9 ft. The deepest cut was 15 ft., and was taken out in one lift by lowering the dinkey track 1^ ft. With the boom raised in this manner it was possible to dig a 13^- ft. lift; and when cuts are, say 16 ft., it is possible to take them out in one lift, by excavating a trench for the dinkey track about 3 ft. deep. The material coming from this trench is placed inside the slope stakes, and later taken out with the shovel. By this method one trackage layout is sufficient for a cut of the above nature. There is no moving back, and there is very little extra material taken out even with a roadbed specified to be only 20 ft. wide. The shovel is a little faster acting with the boom raised, as described, and there is no additional wear and tear on the machinery. The material encountered was almost all stiff clay, with a small amount of loose rock. This shovel has averaged about 25,000 cu. yd. per month, and has only had one breakdown, this being a very small matter. Cost of Steam Shovel Work. Shovels are so designed that about 3 dipperfuls can be averaged per minute when actually loading cars ; but the author finds that even with well arranged tracks, and a good high face, the necessary delays of shifting the shovel ahead, switching the trains, moving the shovel back to start a new swath, etc., keep the shovel idle about half the time. Occasionally, under exceptionally favorable conditions, a shovel may average 6 or 6i/ hr. of actual shoveling per 10-hr, day. The sixe of the dippers, as listed in catalogues often refers to dippers heaped full of loose earth. The actual " place measure " averages about 30% less than the listed capacity of a dipper, for not every dipper goes out full, and, even if it does, the earth is not as compact in the dipper as in place. On the basis of 3 dippers loaded per minute of actual work, we have the following for dippers of different sizes: Dipper Output in Cu. Yd. Nominal, Actual (average) Steady Shoveling Yd. Yd. 10 hr. 5 hr. 1 0.7 1,260 630 \Vz 1.0 1,800 900 2 1.4 2,520 1,260 2% 1.7 3,060 1,530 We see that where the shovel is actually shoveling 5 hr. out of the 10 (and this is a good average), a 1-yd. dipper will load 630 cu. yd.; a 1^-yd. dipper, 900 cu. yd.; a 2^-yd. dipper, 1,530 cu. COSTS WITii S1EAM AND ELECTRIC SHOVELS 401 yd. However, the track arrangement must be such that cars are promptly supplied to the shovel, if any such average as 900 cu. yd. per day per 1^-yd. dipper is to be maintained. Taking the 1^-yd. dipper as the common size, we may say that in " average earth," with cars promptly supplied, 900 cu. yd. are a fair 10-hr, day's work; but if only one dinkey is used, the lost time may easily be increased to such an extent that 650 cu. yd. become a good day's work in " average earth." In hard- pan, or exceedingly tough clay, the output of a shovel may fall to about half the output in "average earth"; that is, 450 cu. yd. per 10-hr, day with a 1^-yd. shovel. The size of shovel to select for any given work depends upon the yardage of earth in each cut not upon the total yardage in the contract. On very light cuts, such as street and road work, cellars, etc., a small shovel with a ^ to 1-yd. dipper is usually most economic. Use a small 26-ton traction shovel, with 1-yd. dipper for small railway cuts, where moves from one cut to another will be frequent. Use a 55 to 65-ton shovel with 1} to 2i-yd. dipper where cuts are heavy, and moves not very fre- quent. Use a 70 to 90-ton shovel, with 2% to 31^-yd. dipper on heavy cuts, where moves are infrequent. Of course a heavy shovel with a small dipper is necessary in hardpan and very tough material. The cost of operating a 55-ton shovel is ordinarily as follows, (at 1914 wages and prices), assuming 22 days worked during the month, and 6 months worked during the year, or 132 days actually worked per year: Per day Shovel Crew: worked 1 engineman on shovel, at $125 per month '. $ 5.70 1 craneman on shovel, at $90 per month 4.10 1 fireman on shovel, at $65 per month 3.00 6 pitmen, at $1.75 per 10-hr, day 10.50 1 night watchman, at $50 per month 2.30 Total shovel crew $ 25.60 Coal for shovel, 1*4 tons, at $4, delivered $ 5.00 Water 3.00 Oil and waste 0.50 Interest on $7,200 shovel at 6% per year -4- 132 days 3.25 * Repairs on $7,200, 3% per month -f- 22 days '. 10.00 Depreciation on $7,200, 6% per year -j- 132 days 3.25 Total steam shovel crew, fuel, repairs, etc $ 50.60 Moving and housing shovel once during year, say, $500 -=- 132 days.. 4.00 Total charges on shovel $ 54.60 * Repairs are less in earth than in rock. In the soft rock on the Panama Canal, monthly repairs averaged 4% of the first cost of shovels, working one 8-hr, shift. 402 HANDBOOK OF EARTH EXCAVATION Train Crew: 2 enginemen (on 2 dinkeys), at $3 $ 6.00 2 trainmen, at $2 , 4.00 6 dumpmen, at $1.75 10.50 Total train crew $ 20.50 Coal for 2 dinkeys, 0.6 ton, at $4 $ 2.40 Water 1.50 Oil and waste 0.50 Interest jon $8,000 (2 dinkeys and 24 cars), at 6% per year -f- 132 days 3.65 Repairs on $8,000, at 1%% per month -i- 22 days 5.45 Depreciation on $8,000, at 8% per year -=- 132 days 4.85 Total train crew, fuel, repairs, etc $ 38.85 Moving and housing locomotives and cars once during year, same as for shovel -4.00 Total charges of locomotives and cars $ 42.85 Track Crew and Track: 6 men grading and track shifting, at $1.75 $ 10.50 Interest on $2,250 (rails (35 Ib. per yd.) and fastenings for 1 mile track) , at 6 the " getting .out of date " or behind the times. Depreciation of ties is especially rapid in contract work, due to the destruction that occurs from frequent track shifting. Depre- ciation of rails is also rapid, due to their becoming kinked. The foregoing itemization of cost should be taken merely to represent a fairly typical example (at prewar wages), but each particular case will have its varying conditions that must be considered. Where temporary trestles must be built to. carry the cars out over proposed fills, as is common on railway work, the cost of the trestles must be added to the above figures. Much lighter timbers can be used for dinkey locomotives and trains than for standard railway tracks. It should also be remembered that round poles can usually be secured for the legs or posts of trestle bents, and that each bent usually has only two legs. The squared stringers, ties and caps can usually be recovered, but the posts, sills and sway braces are buried permanently in the fill. The cost of trestles is given in detail in Gillette's " Handbook of Cost Data." Analysis of Costs of Steam Shovel Work. An abstract from " Handbook of Steam Shovel Work," a report by the Construc- tion Service Co., to the Bucyrus Co., which was given in Engineer- ing and Contracting, Dec. 13, 1911, follows. There are so many factors entering into steam shovel work that the problem of determining the cost details seems at first highly complex, but systematic analysis has resulted in so simplifying it that any man of field experience ought to be able, with the help of the following data, to put his shovel work on a scientific basis. To determine what the work is costing day by day, is half the problem: to determine what it ought to cost is the other half. To establish these factors it was necessary to observe a large number of shovels in operation, and the data given are the re- sults of the observation of nearly 50 different shovels at work in various kinds of earth and rock. The unit costs of working by hand will be nearly the same, field conditions being equal, whether the job is a large one or comparatively small. The steam shovel is dependent for its work upon so many factors, any one of which may greatly help or hinder it, that there is a far greater diversity of results than in the case of handwork. The question of how much work there 404 HANDBOOK OF EARTH EXCAVATION must be to justify the use of a steam shovel is vital in a large percentage of all excavation contracts. Repairs and Depreciation. Repair costs should be apportioned to the work done rather than considered a function of the age of the shovel. It will be higher for rock than earth, and higher for poorly broken rock than for well blasted material. Time alone doesn't affect the unit cost of repairs. In the item of depreciation the reverse of this proposition ob- tains. If the machine be kept in proper repair, the depreciation is effected by time alone, regardless of the work the machine is doing. Many concerns class this item and repairs under one account, but this practice is inaccurate and misleading. There is a great disagreement among accountants as to how depreciation should be figured and there are many so-called depreciation formulas and curves. The simplest to use, and one which for steam shovel work is satisfactory if proper allowance is made for repairs, is the " straight-line formula," which is as follows : (a b) c/d X = . where a = original value, a b = value on removal. c time in use. d = estimated life. X % of depreciation. Then X divided by the output for the period c will be the cost of deprecia- tion per unit of performance. The working life of a shovel may be assumed to be 20 years, and assuming the first cost at $150 per ton, and its scrap value at $10 per ton, the value for X with a 10-year-old shovel, would be ($150-$10) 10 X = 46.67% in the 10 years or 4%% per year. $150 20 The interest on all money invested in this work must be in- cluded in the costs of the work. In this discussion the interest is assumed as 6%. The height of bank to which a shovel can work has an im- portant bearing upon the costs. The reason for this is that the higher the bank the larger amount of material that can be removed without moving the shovel. Cost Formula. The following analysis of steam shovel work is based on the results of observations of about 50 shovels at work. The wages of the different classes of men were standard- ized as listed below for purpose of analytical comparison. In connection with this analysis the accompanying curves of cost are useful in enabling a rapid estimate to be made of the ap- proximate cost of steam shovel work in progress or proposed: COSTS WITH STEAM AND ELECTK1C SHOVELS 405 d =. time in minutes to load 1 cu. ft. with dipper (place measure). c = capacity of 1 car in cu. ft. (place measure). f time shovel is interrupted while spotting 1 car. e time shovel is interrupted to change trains. g time to move shovel. L '= distance of 1 move of shovel.' N number of shovel moves. M minutes per working day less time for accidental delays. A or B = area in sq. ft. of section excavated. R i= cost in cents per cu. ft. on cars, for shovel work only (place measure). L A N cu. ft. excavated per day. C = shovel expense in cents in 1 day, not including superintendence and overhead charges and not including preparatory charges, n number of cars in train. (1) Time to load 1 car = dc. (2) Time to load 1 train :ndc + nf-fe. L A (3) Number of trains for 1 shovel move n c (4) Time between beginning of 1 shovel move and beginning of next = (n d c + n f + e) (- g. n c ' M (5) N = 27Cd 27C/ f " e g \ (6) B 1 1 H 1 I M M V c nc LA / This is equivalent to the equation B = md + b. 27C (7) Where m = , and M (8) b (f e g \ - + + 1 c nc LA / The following standards have been assumed for a shovel valued at, say $14,000: Per year Depreciation, 4%% $ 653.34 Interest, 6% 840.00 Bepairs, when working one shift 2,000.00 $3,493.34 Per day Assuming year of 150 working days * $23.29 Shovel runner 5.00 Craneman 3.60 Fireman 2.40, Vz watchman at $50 per month 1.00 6 pitmen at $1.50 9.00 1 team hauling coal, water, etc., % day, say, at $5 2.50 21/2 tons coal at $3.50 8.75 Oil, waste, etc., say 1.50 Total per day $57.04 * For various reasons, such as lack of continuous work, weather, etc., 150 working days per year is assumed. This will vary greatly with local conditions. 406 HANDBOOK OF EARTH EXCAVATION It appears that the equation . R = md + b is that of a straight line. Now, since the equation 270 f e g m = and b = m ( 1 1 ), M c nc LA all quantities involved in the equation excepting d are, or are assumed to be, constant. The data upon the value of these quantities have been represented in graphic form with all in- fluencing factors by the five figures A, B, C, D, and E. VALUE9-05 270 IN SECONDS M!N. AVO. MAX. (RON 6.1 10.6 15.4 BAND 6. 12.1 10.8 CLAY 10.0 13.3 20.0 ARTH 10.8 18-4. 28.6 ROCK 12.8 30.7 68.0 OlPPEfl CAPACITY W.M. IN YDS. MIN. AVO. MAX. 2.26 2.47 2.6 1.22 2-01 2.8 2.00 2.41 2.00 2.66 3.0 DIPPER CAPAC P.M. IN YDS. MIN. AVG. MAX 1.76 2,33 2.67 1.25* 1.61 26 1.01 PLACE MEASURE ( PM} WATER MEASURE (WM) AVO. MAX 0.7 0.84 1.07 0.66 0.58 0.56 0.4T 0.61 0.77 0.4S 0.63 0.77 0,12 0.43 0.79 IRON SAND CLAY EARTH ROCK NOTE-VALUES OF 27D ARE GIVEN IN SECONDS AND MUST BE REDUCED TO MINUTES FOR USE WITH CURVES OF COST Fig. 18. Diagram for Use with Cost Curves. (Value of 27d Shown Graphically.) COSTS WITH STi'AM AND SHOVELS 407 Fig 18 indicates the time to load 1 cu. yd. plaee measure, in various kinds of material. Fig. 19 deals with the quantities e, 70 ROCK OUTS CRUSHED STONE EARTH AND G. DRIFT 2'45 IRON ORE 7 '45 SAND AND G. PlTS OTE- VALUES Of 6 FOR USE IN COST CURVES MUST BE IN MINUTES 33K93:;3''!S3c:82:t; aosasosffaaeoBs ,a Fig. 19. Diagram for Use with Cost Curves. (Value of e Shown Graphically.) average time shovel is interrupted to change trains. For use in plotting the equation above, those average values of e, n, c and f involved in ordinary contracting work where side dump 408 HANDBOOK OF EARTH EXCAVATION cars are used, have been tabulated separately in Fig. 19. It will there be seen that the average value for e, the time between trains is 4 min. The average number of cars per train, or n = 10. The commonest form of contractors' dump car is 4 yards water measure or 2.5 yards place measure, and therefore c is taken as 67.5 cu. ft. The ordinary value of f is zero, "since the cars are almost invariably spotted while the shovel is swinging 50 PER CENT OF TIME SHOVEL WORKS PER DAV MIN. AVG. MAX. BRICK YARDS 89.25 92.75 95.3 "AND* GRAVEL 81.5 91.8 98.0 "IRON ORE 80.0 91.4 99.25 STRIPPING 79.5 87.6 95.25 _R.R. BORROW PITS 59.79 82.8 96.0 C.STONE O. 72.25 82.2 90.9 ROCK CUTS 44.0 80.13 99.5 VALUE OF "MM IN MINUT MIN. AVO. MAX. 427.8 440.2 4(8.4 549. 548.4 526.6 496.8 402.0 480.0 Fig. 20. Diagram for Use with Cost Curves. (Idle time shown graphically in per cent, of total time per day. Values of " M " to be taken from this diagram. To find " M " take value plotted below subtract from 100% and multiply result by total working time per day, generally 10 hours.) and digging. Fig. 20 deals with the value of M or the working time, including actual shovel time waiting for trains and mov- ing up, but not accidental delays. Fig. 21 deals with the time of moving up, an average value for which is 8 min. The constants having thus been established, three sets of curves have been plotted on Figs. 22, 23, 24 which are cost curves. Each plate is plotted with one of the three values of L A 1,500, 3,000 and 0,000 cu. ft. (L being the average shovel move, 6 ft., and A the area of the dug section in sq. ft.). Each of these sets of curves has been plotted for values of M, ranging from COSTS WITH STEAM AND ELECTRIC SHOVELS 409 2 hr. to 10 hr. by hourly intervals between which intervals the observed values (see Fig. 20) fall. Estimating. There are two important uses to which these cost curves can conveniently be put, ( 1 ) estimating the cost of proposed work and (2) checking up the cost of work under way. In estimating we may proceed as follows: Assuming that the proposed work is to be a railroad cut in rock, with average equip- ment, there are then only three quantities to decide upon, namely, LA, 27d, and M. The area of the shovel section being assumed at 250 sq. ft. and the average distance of move being 6 ft., LA TIME MUST BE READ IN MINUTES 19 18 VALUES OF y MIN. AVO. MAX. NO 19 OBS, Q - 1^430 7/ 59" 19'48 I DISTANCE OF SHOVEL TO MO ^ 17 16 : NO. " OBSERVATIONS MIN. AVO. MAX. 3 16 it! - 49 3'0" 6'0" 15'"" / j- 915 ^n /- 14 i '-'--- 13 a12 ?11 * Jio *" fl J - 10 2? 9 H 8 Ubll JMl - V ie x^~\ \ O 5 , 4 3 / ^^ : 3 f Fig. 21. Diagram for Use with Cost curves. (Value of g Shown Graphically. Read Time in Minutes.) will equal 1,500 cu. ft. Now refer to Fig. 18, and select a fair value for the time of loading 1 cu. yd. in rock work. Suppose 30 sec. be chosen. Next refer to Fig. 20 for the proper value of M to use in rock work. The average value is 8 hr. (80% of 10 hr.). The cost per yard in cents can now be read directly on cost curves, Fig. 23. With abscissa (27d) as 30 sec. glance upward till the vertical line through 30 sec. intersects the 8 hr. M line. Then on the left, opposite this point of intersection read 9^ ct. as the cost per cu. yd. loaded, place measure. It may be noted here that with respect to the two important items of time to load 1 cu. yd. with dipper and values of M, the cost curves are perfectly flexible. Variation in the value of 410 HANDBOOK OF EARTH EXCAVATION the constants may be allowed for by proper choice of M. In connection with the formula it is interesting to note the effect of decreasing the carrying capacity of each train, other con- ditions remaining the same. Suppose the carrying capacity be decreased from the average 10 X 2.5 yd. 25 cu. yd. to 8 X 2 = 16 cu. yd., place measure, what would be the effect upon the cost per cu. yd.? The new cost would be 10.6 ct. per cu. yd. as against the former 9.5 ct., an increase of 10%. To use the cost curves for checking up the cost of work in progress, proceed as follows: The field operations are few and simple. Find the average time per dipper swing. Knowing the rated capacity of the dipper and the character of the ma- WHERE LA 1800 CU.FT. EXCAVATION TO EACH SHOVEL MOVE 10 20 80 40 80 70 80 CO ICG TIME TO IOAD 1 CU.YO., PUCE MEASURE WITH DIPPER WORKING FREELY IN SECONDS Fig. 22. Cost Curve. terial, a glance at the tabulation near the top of Fig. 18 will give the ratio of dipper capacity place measure to dipper capacity water measure, and by using this factor the average factor of dipper (place measure) can be obtained, and thence the time to load 1 cu. ft. or yd. Suppose, for instance, the average time per swing to be 25 sec., in earth material, and the capacity of dipper, 214 yd. On Fig. 18, under ratio of place measure: water measure, we find the average value is given as 0.53. Therefore, 21/4X0.53 = 1.2 cu. yd. per swing or 2.88 cu. yd. per min. or 0.35 min. per cu. yd. Make some rough measurements to deter- mine the approximate area of the shovel section and multiply this area by the length of move, and get LA, say 3,000. -Then, from previous observations or by an estimate of M, get the time worked per day, less accidental delays, say 9 hr. Now take the COST! WITH STEAM AND ELECTRIC SHOVELS 411 cost curves, Figs. 22 to 24, and with .21 as abscissa, read oppo- site the line, for Mr=:9 hr., 6 ct. as the cost per yd. place measure. If the contents in the formula do not agree closely enough with the actual conditions, allow for this by choosing a suitable value of M, or substitute directly in the equation for cost. 27Cd 27C Formula R = M M V c nc LA Assume f o, interruption of shovel while spotting cars. e 4 niin. time between trains. n = 10, number of cars per train. c = 2.5 yd. place measure = 6.7 cu. ft. C = 5,704 ct., daily cost. M = actual working time of shovel. g = 8 minutes, see Fig. 4. d = Minutes to load 1 cu. ft. place measure. It should be noted that the above does not include superin- tendence or overhead charges and covers only the cost of loading. It should be particularly noted that for plotting the two co- ordinates, certain assumptions are necessary because there are a large number of variables in the theoretical steam shovel formula. 10 20 80 40 50 60 70 80 90 100 TIME TO LOAD 1 CU.YD., PLACE MEASURE WITH DIPPER WORKING FREELY, IN SECOND- Fig. 23. Cost Curves. (From Daily Cost " C." Itemized in Text.) Thus, the three diagrams are given one for LA = 1,500, one when LA is 3,000 and one where it is 6,000. Also an assumption of $57.04 for the value of C is made. Where the shovel differs very much in type from the one mentioned, or where the rates of wages are very different from those assumed, it will be neces- 412 HANDBOOK OF EARTH EXCAVATION sary to compensate for the difference between the new value of C, and the one used here. The easiest way to do this is to multiply the figures taken from the diagram by the ratio between the new value of C and the assumed one. Thus, if the shovel costs per day are $65 instead of $57.04, and the diagram should give a cost for loading of 12 ct., we would have for our charge 12 ct. multiplied by $65 and divided by $47.04 or 13.67 ct. per yd. The quality and amount of superintendence will greatly affect the unit costs of the work ; and by superintendence is meant, not only the man in charge, but his whole directing organization. WHERE LA = 6000 CU .FT. EXCAVATION TO EACH SHOVEL MOVE 10 20 SO 40 60 bO 70 80 90 100 TIME TO LOAD 1 CU.YO., PLACE MEASURE WITH DIPPER WORKING FREELY. IN SECONDS Fig. 24. Cost Curve. (Value Same as Figs. 22 and 23.) The work in the iron ore country is an example of the work which may be accomplished in the way of skilled organization. Pure observation alone without actual timing will not show a superintendent whether it is more economical for him to use 9 or 10 car trains to haul material away from his shovel. He will generally favor the use of long trains if his engines will haul them. Yet money has been saved by shortening trains even when the engines could easily haul the longer ones. In this case the key to the situation was the time required to dump and transport. Values of e, n, c, f, involved in ordinary contracting work with side dump cars. e Average time shovel is interrupted to change trains. n := Number of cars per train. c Capacity of cars in cu. ft. (place measure). / = Time to spot one car. c' Capacity of cars in cu. ft. (water measure). COSTS WITH STEAM AND ELECTRIC SHOVELS 413 Values of n Values of c Min. Avg. Max., Min. Avg. Max. Brick yard clay 1 1-2 2 54 72 81 R. R. borrow pits 7 11 15 83.7 126 270 Rock cuts 7 9 12 54 75 97.2 Crushed stone quarries 1 10 10 108 124 189 Earth and glacial drift. 10 10-11 13 70 108 141 Iron ore (Minn.) 3 7 12 270 540 675 Sand and gravel pit ... 1 7 15 67.5 598 891 Zero 151 188 162 157 540 General average of e, n, c, f, c' , as follows n c c' c/c' No. of Obs. 35 35 35 27 27 Minimum .25 min. .0 cars yd. yd. Average 4.00 min. 10.00 cars 4.00 yd. 5.00 yd. 0.8 Maximum 13.5 min. 15.0 cars 10.00 yd. 12.00 yd. 0.95 Repairs of Steam Shovels, Cars and Locomotives on the Panama Canal. The following is an abstract of the "Annual Report of the Isthmian Canal Commission " printed in Engineer- ing and Contracting, Dec. 22, 1909: According to the last annual report of the Isthmian Canal Commission, the following were the principal items of equipment used in excavating and transporting earth and rock, on June 30, 1909: TABLE FOR USE WITH COST CURVES Steam Shovels: 1 (20-ton) shovel, l^-yd. dipper % 5,788 10 (45-ton) shovels, 1%-yd. dipper, at $7,100 71,000 42 (70-ton) shovels, 2M>-yd. dipper, at $9,381 494,002 47 (95-ton) shovels, 5-yd. dipper, at $12,760 599,720 100 total steam shovels, at $11,705 $1,170,510 Locomotives : 119 French locomotives, at $4,250 $ 505,750 164 American locomotives, at $11,600 1,902,400 283 Total locomotives, at 8,509 $2,408,150 Cars: 621 French dump cars at $225 $ 139.725 1,324 American dump cars at $1,400 1,853,600 1,765 wooden flat cars at $1,050 1,853,250 500 steel flat cars at $861 430,500 35 narrow gauge cars at $227 7,945 4,245 Total cars at $1,010 $4,285,020 : ' : ; i f Unloaders, etc. : 30 Lidgerwood unloaders at $5,000 $ 150,000 46 unloading plows at $950 43,700 24 bank spreaders at $5,200 124,800 10 track shifters at $4.050 40,500 16 pile drivers at $3,700 59,200 Total unloaders, etc $ 418,200 Grand total $8,281,880 414 HANDBOOK OF EARTH EXCAVATION The 100 steam shovels averaged a 78-ton weight, and a first cost pf $140 per ton; and daily repair cost of about $25. The prices paid for this plant include the cost of delivery at Colon. The cost of shop repairs made by the mechanical division dur- ing the year on the different units of equipment enumerated in the above table, including direct and overhead charges, was as follows : Each per annum 283 locomotives (93 repairs on each) $1,226 4,210 freight cars (29^ repairs on each) 150 119 work cars (7 repairs on each) 338 100 steam shovels (shop repairs only) 1.976 The total shop repairs on these locomotives, cars and steam shovels amounted to $1,217,058 for the year, not including field repairs on the steam shovels. While the report does not give field repairs, we have included here some data taken from the Canal Record and published in our issue of Oct. 20, 1909. The shop cost does not include the cost of repairs made in the field or that of repairs made to steam shovel parts taken to the shops while the shovel is kept in service by substituting other parts. These repairs are known as field repairs and are made in the field shops and on the work, often while the shovel is waiting for cars. The cost of steam shovel repairs in the three con- struction divisions from January, 1908, to June, 1909, inclusive, a period of 18 months, was 3.03 ct. per cu. yd. for 33,882,000 cu. yd. Item Central Cubic yards 27,752,750 Field cost $596,059,02 Shop cost $283,746.76 Cost per cu. yd. Field Shop Ct. 2.14 1.02 Atlantic 4,148,997 $51,786.74 $51,782.61 Pacific 1,980,069 $19,917.58 $22,246.75 Ct. 1.25 1.25 Ct. 1.01 1.12 Total 33,881,816 $667,763.34 $357.776.12 Ct. 1.97 1.06 Total 3.16 2.50 2.13 The shovels in the Central Division are subjected to harder and more constant usage than those of the other two divisions. Of the 101 steam shovels in the Canal and Panama railroad serv- ice 61 are in the service of the Central Division, most of them in Culebra Cut. The repairs on locomotives and cars include field repairs as well as shop repairs. It will be noted that locomotive repairs amounted to 14^% of the first cost of the locomotives. This is about the percentage it costs to maintain railway locomotives COSTS WITH STEAM AND ELECTRIC SHOVELS 415 in America, exclusive of entire renewals of worn out equipment, but the report does not give the weights of locomotives, so it car not be determined whether the price of the French locomo- tives is a second-hand price or not. As the locomotives grow older, the cost of repairs will increase, unless the efficiency of the men engaged in repair work increases. The total cost of repairing cars was about 15% of the first cost. The shop cost of repairing steam shovels was 17% of the first cost. The average shovel has been put into the shop for general repairs once in 24 months, and that $3,800 was spent on each shovel during such period of general repairs. As above shown, the field repairs averaged twice as much as the shop repairs; hence the combined annual field and shop repairs totaled 50% of the first cost of the shovels. For total " maintenance and repairs," "the mechanical depart- ment expended the following sum during the year : Materials $ 595,050 Labor 1,245,448 Total $1,840,498 This is $623,000 more than the total cost spent on the steam shovels, locomotives and cars, and probably covers repairs to all other parts of the plant, including rock drills, etc. Expenditures of the mechanical department for work done for "other departments" was $1,504,315, but this is not itemized. The monthly payroll of the mechanical department was $159,- 934, for 2,125 employees. The following rates of wages were paid, and the percentage by which their wages exceed those paid in the U. S. navy yards: Wage, Per cent. Blacksmith 8 hr. increase 59 general $4.74 31 5 machine 5.25 37 3 brick layers or masons 5.76 19 138 boiler makers (general) 4.86 41 180 carpenters (house) 5.36 52 34 molders (loam) 5.47 51 26 painters (house) 5.06 55 6 pattern makers :... .'... 6.18 52 33 pipe fitters 5.15 44 33 plumbers (house) 5,92 55 2 tinsmiths 5.52 62 7 coppersmiths 5.33 42 5 engineers (steam) 4.77 40 Machinists 269 general 4.91 37 58 floor hands '. 5.10 43 38 tool hands 4.82 33 33 wire men (electric) 4.93 46 929 total- 416 HANDBOOK OF EARTH EXCAVATION " So far as hourly rates of pay for ' gold ' employees are con- cerned, the first-class pay remains almost uniformly 65 ct. an hour ($5.20 for 8 hr.)." The following data are taken from the Panama Canal special issue (66 pages) of Engineering and Contracting, Jan. 7, 1914. Five sizes of shovels were employed as follows: Dipper Name capacity 45-ton Bucyrus 1% cu. yd. 70-ton Bucyrus 2% cu. yd. 95-ton Bucyrus 5 cu. yd. No. 60 Marion 2V 2 cu. yd. No. 91 Marion 5 cu. yd. The number of each type used each year varied; the number of all shovels used each year and the average output of all shovels are given in Table I. These performance records and all others which will be stated are based on an 8-hr, working day. The best performances per day, month and year of steam shovels of the sizes named above for the five years are given in Table IT. Maintenance of Shovels. Steam shovels were maintained by shop and field repairs. Priod to Oct. 1, 1909, all shop repairs of steam shovels were made at the Empire shops and were in charge of the Mechanical Division and all field repairs were made by the construction division. On the date named the Empire Shops were removed from the direction of the Mechanical Division and transferred to the Central Division, and were made virtually steam shovel repair shops for the whole canal. A field repair system was begun Nov. 5, 1907, and it comprised a force of boiler workers, pipefitters, machinists and helpers who made all repairs at night after the shovels were shut down. The force was divided into three gangs, each covering a certain section of the excavation. A machine shop car, equipped with a forge, drill and shaper and carrying necessary small tools, and a locomotive crane constituted the field repair plant. The field repairs included replacing and repairing circles, booms, dippers and dipper sticks. A-frames, hoisting drums, main and pro- peller shafts, swinging drums, intermediate shafts, water tanks, feed pumps and trucks and in one or two cases even renewal of boilers. In fact it was seldom that a shovel was sent to the shops for repairs short of complete overhauling. The numbers of shovels repaired per night by the field repair gangs run from 14 to 20. COSTS WITH STEAM AND ELECTRIC SHOVELS 417 T . It is made by the M. & M. Rail Clamp Co., Pittsburgh. Pa. Another steam shovel rail clamp works like a pair of ice tongs. It grips the ball of the rail and the wedge is driven across the top of the rail; it can therefore be placed anywhere on the rail, even directly over a cross-tie, as in Fig. 30. There are only two parts, the wedge of hardened steel and the tongs which are steel castings hinged by a heavy pin. These clamps are made in three sizes (for 50-60-lb., 70-80-lb., and 90-100-lb. rails) by the Bucyrus Co., South Milwaukee, Wis. A Flexible Rail Joint. Engineering and Contracting, March 18, 1914, gives the following: The construction and operation of the Thull joint for steam Fig. 31. Side Elevation and Horizontal Section of Thull Rail Joint. shovel tracks are indicated in Fig. 31. It consists of a male casting A and a female casting B. These castings are bolted to the rail ends and are hinged by a bolt C as shown by the draw- ings. The hinge C provides for joint rotations in the vertical plane; lateral flexibility is provided by the beveling of the socket and other parts by which the two castings engage. A track spike dropped into each of the notches D and E prevents lateral move- ment while allowing vertical rotations. The other structural COSTS WITH STEAM AND ELECTRIC SHOVELS 427 details are plain from the drawings. This joint has been patented. A Device for Lifting Jack Blocks. Engineering and Contract- ing, Dec. 11, 1912, gives the following: A simple device for lifting jack blocks so that they are pulled ahead by the steam shovel itself as it is advanced for a new cut as illustrated in Fig. 32. This device has been used for some time at Lockport, 111., where the Lincoln Park Commis- sion of Chicago has a shovel and plant for excavating and loading black soil for park surfacing, and it is the invention of Mr. George T. Dows, the superintendent in charge of the shovel and plant. We are indebted to Mr. Dows for sketches and an explanation of the device. 9 , ^jj Fig. 32. Device for Lifting and Moving Steam Shovel Jack Blocks. Referring to the sketches: A indicates the end of a Vulcan shovel jack arm with jack screw, shoe and blocking in working position; B is a % x 2-in. steel bar 4 ft. long called a fulcrum bar and C is a % x 2-in. bar 6 ft. long called the lever bar. The fulcrum bar rests across the top of the pick arm when it is held in position by the "Lg" D and the "latch" E, The " latch " has a hook at its top and an eye at its bottom. In the Vulcan jack arm, for which the device was designed, the bolt F passes through the eye of the "latch"; in other makes of jack arms which do not have bolts, some other fastening must be devised. The lever bar is hinged to the fulcrum bar as indicated by the sketch; it has a hook at one end and an eye or hand hole at the opposite end. A small rope hangs from the hook end and is attached to an eye bolt set through the. jack block. The first sketch shows the position of the jack and block- ing when the shovel is working. When about to move the shovel a,head the jack screw is loosened and the blocking G is slid from under the shoe. The lever bar C is depressed and locked to the 428 HANDBOOK OF EARTH EXCAVATION fulcrum bar by means of the hook H. This raises the jack block to the position shown by the second sketch and in this position it is easily dragged ahead by the shovel as it moves up to the new cut. A series of operations in reverse to those just out- lined adjusts the blocking and jack for .the new working posi- tion. Specifications for Steam Shovel Construction. Engineering and Contracting, May 1, 1909, prints an abstract of a report by the Committee on Roadway of the American Railway Engineering and Maintenance of Way Association: One of the tasks allotted to this committee was to submit general specifications for a modern steam shovel for roadway construction and blanks to show the results of steam shovel work, including quantity of material moved and itemized cost of re- moval. The committee sought the opinion of the association's members by means of a circular letter of inquiry and bases its recommendations on the replies received. The questions, the answers received to them and the decision of the committee are summarized in the following paragraphs: Irrespective of the use, there are three important cardinal points that should be given careful attention in the selection of any and all machines of this class. These are in their order: ( 1 ) Care in the selection and inspection and acceptance of all material that enters into every part of the machine. (2) Design for strength. (3) Design for production. With the foregoing fixed firmly in mind, we submit specifica- tions for a Standard Shovel, which we believe will meet the largest requirements for " General Roadway Construction." Weight. Shovels varying in weight from 25 to 90 tons are recommended. The committee recommends 70 tons. Capacity of Dipper. Replies received vary from Ity cu. yd. to 5 cu. yd.- The committee recommends 2^ cu. yd. Steam Pressure. From ICO Ib. to 200 Ib. is recommended. The committee recommends 120 Ib. Clear Height Above Rail of Shovel Track at Which Dipper Unloads. This height is recommended at different points, vary- ing from 8 ft. to 18 ft. The committee recommends 16 ft. Depth Below Rail of Shovel Track Dipper Will Dig. The re- plies vary between 2 ft. and 8 ft. The committee recommends 4 ft. Number of Movements of Dipper Per Minute from Time of Entering Bank to Entering Bank. From one to six movements are mentioned. The committee recommends three. Cable or Chain Hoist. Seven replies favor the cable and 27 recommend the chain. This subject has been given very careful COSTS WITH STEAM AND ELECTRIC SHOVELS 429 consideration and on account of the economical cost of renewals and repairs the committee recommends cable hoist. Friction or Cable Swing, Seven vote in favor of friction and thirty-one recommend cable. The committee recommends cable swing. How Extensive Housing Should be Provided for Engineer, Fire- man and Cranesman. The replies received from 26 members recommend permanent housing, while 10 favor temporary pro- tection. We believe that this matter has not been given the attention of manufacturers and others that it demands, although the engineer and fireman are usually well protected, the cranes- man is entirely unprotected, and if he is to be retained as a necessary employee, he should be housed. The committee recom- mends permanent housing for all employes. Capacity of Tank. Tanks varying from 1,000 gallons to 7,000 gallons are recommended. Believing that it is possible to pro- vide shovel with water at least every twelve hours, the com- mittee recommends 2,000 gallons. Capacity of Coal Bunker. From one ton to six tons are recom- mended. Ordinarily a day's supply should be provided, and the committee recommends four tons. List of Repair Parts Necessary to Carry. From the various replies, the committee recommends the following: 1 hoisting en- gine cable or chain, 1 thrusting engine cable or chain, 1 swinging engine cable or chain, 1 set dipper teeth, 1 dipper latch, 12 cold shuts, 6 cable clamps, 1 U bolt, duplicate of each sheave on machine, lot assorted bolts and nuts, lot assorted pipes and fittings, lot assorted water glasses. Give List of Repair Tools Necessary to Cover. 1 blacksmith forge with anvil and complete tools, 1 small bench vise, 3 pipe wrenches (assorted sizes), 3 monkey wrenches (assorted sizes), 6 Chilson wrenches (assorted sizes), 1 ratchet with assorted twist drills, 6 round files (assorted sizes), 1 hack-saw (with twelve blades), 1 set pipe taps and dies, 1 set bolt taps and dies, 6 cold chisels (assorted sizes), 2 machinists' hammers, 2 sledges, 2 switch chains, 2 re-railing frogs, 2 ball-bearing jacks, 1 siphon (complete), 1 axe, 1 hand saw, 1 set triple blocks with rope, 2 lining bars, 1 pinch bar, 6 shovels, 6 picks, 1 coal scoop, 1 flue cleaner, 1 fire hoe, 1 clinker hook, 1 slash bar, 2 hand lan- terns, 2 torches, assortment of packing, assorted oil, in cans. What Spread of Jack Arms. Replies received show a great difference of opinion varying from 14 ft. to 28 ft. Having in mind that it is often necessary to provide for narrow cutting, the committee believes that an extra short-arm should be pro- vided for each shovel. The committee recommends 18 ft. 430 HANDBOOK OF EARTH EXCAVATION Recommended Practice in Shovel Operation. The following recommendations were made by the Committee on Roadway of the American Railway Engineering and Maintenance of Way Association at the annual convention of 1917, and are intended to supplement previous recommendations embodied in the 1915 edition of the Manual of the association. Size of Shovel. For light grading, up to 25,000 cu. yd. per mile, where a shovel can be used economically, a light revolving shovel is to be desired. For 25,000 to 40,000 cu. yd. per mile, a shovel of 50 tons is a good size. For 40,000 to 00,000 cu. yd. per mile, a shovel of 60 to 80 tons is well suited. For anything over 60,000 cu. yd. per mile, the shovel may run up to well over 100 tons economically if its transportation is not too expensive, and if the ground is fit to carry the weight on sub- grade during excavation. The greatest cause of delay in steam-shovel work is in the removal of the excavated material. Too great care and attention cannot be given to securing proper and ample equipment in the matter of cars and locomotives, and in the proper systematiza- tion of service, track, transportation and disposal. The eco- nomic success of a steam shovel depends, above everything else, on having an empty car always ready to replace a loaded one under the dipper. Too great stress cannot be laid on this point. Careful management, through organization and unceasing super- intendence and foresight only, however, can accomplish satisfac- tory results even with a thoroughly-equipped plant. As the plant charge against steam-shovel work is always an important item, especially where the haul is long, requiring a large equipment of cars, and locomotives, continuous operation is desirable. For this reason, either three 8-hr, shifts or two 10-hr, shifts are recommended. Where the service is not too trying on the machinery, three 8-hr, shifts are more economical, if they do not upset other parts of the organization. When, however, the work is severe, two 10-hr, shifts are preferable, as this arrangement gives two hours between each shift for re- pairs and overhaul in the plant. For night work, where elec- tricity is not available, a small turbo-generator set, similar to that used on a locomotive, can be set up on the shovel for lighting the immediate works. An old locomotive tender is a very valuable adjunct to a steam shovel, especially where delays may be caused from irregularity in coal and water supply. The greatest cause of stoppage in the shovel proper is due to care^ssness or incompetence in the operator. He should see that COSTS WITH STEAM AND ELECTRIC SHOVELS 431 his engine-room and all moving parts are kept thoroughly cleaned and accessible. He should train his pit gang to watch the under- gearing and track. He must see that his boiler is washed out as often as necessary, depending on the water used, and that his flues, heads and sheets are tight arid in repair. He must continually inspect all parts liable to wear or extraordinary strain and make renewals before the accident occurs. He must have a light and accurate hand on the propelling lever and must judge his load on the hoisting chain or cable, especially in an over-powered shovel. Heavy breakage in hoisting chains in such a case is almost alw r ays due to an unskilled or careless operator. The mechanical delays on a good shovel operated by a good runner are almost negligible. Repairs. A good works superintendent or master mechanic can develop good shovel runners if he has time and patience. This, of course, is often difficult on railway work, especially in the Maintenance of Way operations. With average runners, the commonest repairs are as follows: Hoisting cables. Hoisting chains. Swinging cable. Teeth and tooth bases. Friction bands and blocks. " U " bolts or double bolts and yoke. Pinions (especially shipper shaft). Dipper latch and hinges. Dipper stick (in hard digging). Sheaves and pins (especially at end of boom and padlock block.) Shipper shaft. Crankshaft on boom engine. Eccentric straps. Bearings. Arm jacks. Rack bolt",. Clevis strap between dipper and bail. Ordinary engine repairs. Ordinary boiler repairs. Ordinary pipe fittings. In the above list of most common repairs much of the trouble is undoubtedly due to lack of proper inspection and judgment in removing worn parts before they actually break, also to care- less handling of the shovel when unusual strains arise in heavy digging. Where a good runner is secured tht repairs will be very small. Where the work is near a base of supplies, the stock parts carried may be very small. There are also many repairs that may be made by the job blacksmith without special stock. Repair parts to be stocked for emergencies when shovel is built as recommended, are as follows: 432 HANDBOOK OF EARTH EXCAVATION 6 cold shuts for hoisting chain. 3 cold shuts for propelling chain. 1 swinging cable, cable sheave and pin. chain sheave and pin. set teeth. tooth base. clevis strap connecting bail and dipper. 2 bolts for yoke, or 2 " U " bolts. 1 set friction blocks. 1 pair each size, bronze bushings. babbitt, if used anywhere. 1 set piston rings. 6 water glasses. Miscellaneous assortment of packing. Miscellaneous assortment of bolts. Miscellaneous assortment of pipe and fittings. Tools. The following list of tools is generally recommended. The assortment is very complete and may be reduced at dis- cretion, depending on the proximity of other ready means of supply and repairs : 100-lb. anvil. 1 axe, chopping, 4^-in. 1 bar, buggy, 3-ft. 1 bar, claw. 6 bars, lining. 1 bar, slice, fire, 5-ft. 1 set blacksmith tools. 2 blocks, snatch, 6-in. Set of bolt taps and dies, with holders. 1 brush, chain, long handle. 2 buckets, G. I., 2-gal. 1 cable, %-in., 60 ft. long. 1 can, oil supply, 1-gal. (kerosene). 3 carriers, timber. 6 chisels (two flat, two round, two cape). 2 containers, oil, 5-gal. 1 cooler, water, 8 gal. 2 cups, drinking, enamel. 1 cutter, pipe. 1 cutter, gage glass. Set of twist drills. 1 flue cleaner. Forge, blacksmith, portable (with coal). 1 gage, track. 1 pair frogs, rerailing. Set of taps and dies, with holders. 1 hacksaw, adjustable, 8-in. to 12-in. 2 hammers, B. P., 1% to 2 Ib. 6 hammers, sledge, double-face, 8-lb. 1 hammer, sledge, double-face, 16-lb. 1 hoe, fire, 5-ft. 60 ft. hose, canvas, 1%-in. 2 jacks, ball-bearing (size dependent on shovel). 1 lantern, hand. 2 oilers, long spout. 3 padlocks. 3 picks, clay. 1 pot, tallow. 1 rake, fire, 5-ft. 1 ratchet, drill. 1 saw, crosscut (two-man), 5-ft. 1 saw, hand, crosscut, 26-in. , COSTS WITH STEAM AND ELECTRIC SHOVELS 433 1 screwdriver, 12-in. 6 shovels, round point, short handle, No. 2. shovel, scoop, No. 3. vise, combination, pipe and bench. wrenches, monkey, 6-in., 8-in., 12-in. and 18-in. wrenches, Stillson, 6-in., 18-in., 24-in. and 36-in. set wrenches, single-end, %-in. to 2%-in. Locomotives. The type and size of locomotives used on steam- shovel work must depend on the character of the work, weight of trains, the length of haul and the local conditions. On maintenance work, ordinary road engines are usually well suited, especially if an ample tail track is provided in the pit that too much- shunting is not required. On construction, where the track is apt to be bad and curves abrupt, the 4- or 6-wheeled saddle-tank type is preferable, at least near the shovel. If the haul is long and the track is fair, heavier locomotives should be used in transportation. In general, on construction where the tracks are inclined to be rough and curves sharp, the shorter the wheel base on a locomo- tive the better, within limits. Where road engines, or even heavy switch engines, are used, there is always danger of de- railments and frame breakage. Where " dinkeys " are used, it is well to pay special attention to springs, brakes and the loca- tion of the center of gravity with reference to the wheel base. Some makes are so balanced that under heavy loads and on steep grades, two wheels are sometimes lifted clear off the track, with the natural resulting delays, if not damage. Track. The shovel track should be made up of 6-ft. sections, with strap connections. Bridles of ^-in. by 2-in. iron should be used, with wedge grips. A notched tie should be used as a check, behind the front trucks, supported by steel saddle clamps at- tached to the rail with wedged grips. Similar clamps should be placed before the front wheel without tie check. Nothing less than GO-lb. rail should .be used under a shovel, and heavier rail should be used under the larger models. No spikes are used. On the muck track in tunnels standard-length rails are used, spiked to the ties. Where no tail track is possible and the excavation is at a breast, drive rails are very useful. These con- sist of half-length rails laid on their sides, with the ball of the rail -against the inside of the web of the last rail spiked down. As the breast is cleared away, these short rails are driven ahead and the cars are run out on the balls of the capsi/ed rails. When a half-length is thus driven out, it is turned right side up and spiked lightly in position and the other half-length driven out in a similar manner. 434 HANDBOOK OF EARTH EXCAVATION Preventing Freezing of Dump Car Bottoms. Engineering and Contracting, Apr. 17, 1918, gives the following; A hot salt solution is employed on the Mesabi Range for pre- venting the freezing of the bottoms of the dump cars used in connection with the steam shovel stripping. A rectangular wooden box of 2,000 gal. to 2,500 gal. capacity is used for a salt tank. The salt is added to the water until a solution is obtained, the common method being to add salt until the solution will float a potato. Steam to keep the solution at a boiling point is obtained from a near-by power or pumping plant or from a small vertical boiler especially installed for this purpose. The cars are sprinkled with the hot solution by means -of a hose. Management of Steam Shovel Work. The following is taken from the " Handbook of Steam Shovel Work " published by the Bucyrus Company. This volume contains many examples of shovel work together with cost data as reported to the Bucyrus Company by the Construction Service Co. Some of these exam- ples are quoted by numbers so that they may be compared with the diagrams. Lost Time. Steam shovel operation is rarely a continuous performance, so far as concerns the shovel itself. There are al- ways delays, some of which are due to breakages on the shovel itself and some to interruptions of one of the collateral proc- esses, breaking or transportation. The most costly of these has been where the shovel was loading blasted rock, and because of imperfect breaking the shovel had to stop from time to time to allow drilling and blasting under the dipper. In one case the interruptions from this cause amounted to nearly 50%, which in an 8-hr, day allowed the shovel only four hours for actual work. Under such conditions the transportation facilities must be adequate to keep the shovel working full time, so that delays to the shovel increase the cost of transportation correspondingly. Accidents to the transportation department, due to bad con- dition of the equipment, rolling stock, or track, cost just as much as delays of the same duration caused by shovel break- downs. Reserve equipment will often save money in such a situation, but the best safeguard is to give to one man the facilities and responsibility for seeing that all equipment be kept in first class repair. It is customary for shovel crews to make their repairs to the shovel out of working hours and on Sundays whenever possible. On heavy rock work, where many repairs are needed, the crews often have to work nearly every Sunday for an entire season, and the consequent lack of rest and recreation is likely to tell on the men's working efficiency. COSTS WITH STEAM AND ELECTRIC SHOVELS 435 Stopping to " chain out " boulders on heavy rock work in shale or the schist of Manhattan Island is likely to account for a lost time bill of 20% or more, and presents a most aggravating and discouraging obstacle to good work. In such cases several extra chains should be provided, and two or three men con- stantly employed in putting them on the boulders as fast as possible while the shovel is working. Even if these men are often idle for several minutes at a time, the result, in shovel output, of their services is worth more than their pay. After estimating how many cents each dipper swing is worth in pay yardage, it is a simple matter to calculate how much should be spent in keeping the dipper working. Mud-capping the bould- ers, to save " chaining out," is desirable if it can be done with- out too much delay. Usually it will be found cheaper in the end to keep a man or two drilling block holes, especially if the facilities permit the use of a small power drill. When thus drilled the boulders can be cracked with small charges and with almost no interruption to the shovel work. With the small drill (like a riveting gun) the holes may be put in on the side of the boulder away from the shovel, if that side can be reached, drilling about 6 to 10 in. deep, tamping with bh e clay forced in with the thumbs and fired with a fuse. Very small charges of a rather high powder (50 or 60%) should be used. A list of the various causes of delay should be kept by the shovel runner, and reported daily, with the duration of each, so that the relative importance of the different causes may be known, and a standard remedy adopted. Whenever such a remedy is needed, the shovel runner can call for it by a whistle signal. The following is a convenient code for these signals, a long toot being indicated by a dash, a short one by a dot: Pit crew get ready to move shovel. Get ready to mud cap. Get ready to block hole. We need coal. We need water. W T aiting for cars (useful to help in spotting cars when dinkey man cannot see hand signals). Stop. All ready to blast.. Fire. Cars off the track. Back up. Shovel has broken down, = ^ Superintendent's call. 436 HANDBOOK OF EARTH EXCAVATION A code of these signals in the shovel cab, and one in the hands of each foreman, will be sure to save money by the elimination of the preventable delays. Kind of Labor Running a shovel is a highly trained and a highly paid specialty, and as a general thing shovel runners are intelligent and conscientious, but a good deal depends on the way in which a runner and his craneman work together. If they should be of incompatible dispositions it is often better to move one of them to some other shovel than to have them work badly together. They must have considerable confidence in each other in order for the attainment of the highest efficiency. We cannot too strongly emphasize the importance of selecting the most skillful shovel runners and cranemen. The loss of money caused by indifferent ability in these positions may easily be several times as much as the wages of the men themselves. We have elsewhere shown the economic effect of efficiency in moving the shovel. For this reason the pit crew should be made up of picked men, one of them getting a little more pay than the others perhaps and having authority over them. Thorough organization here may be worth half of the wages of the pit crew. Of great importance in many classes of work is the dump gang, which usually receives but scant attention. In sandy ma- terial there should be no difficulty in dumping the cars with great regularity and returning them to the shovel on time, but with clay mixed with boulders a good dump foreman and a lively gang are necessary for good work. The men must realize that they are part of a large machine and that their own delays will impede their fellow workmen. For this reason it is often well to alternate the foreman and some of the men between the differ- ent positions. A foreman on the dump will better realize what is expected of him after he has had experience in the pit and on the track laying. Some of the more intelligent men will also be benefited in like manner, while others of less intelligence will not. Estimating. For purposes of estimating, in order not to forget anything and to facilitate a logical arrangement of the various costs that occur on the work, it is important to have some standard classification of expenses. The ordinary costs are in- cluded in the following list, which is used by the Construction Service Company as a standard g..ide, and which will be found useful as a guide to properly subdivide the cost keeping in the field, and as an aid to the bookkeeper. By using the symbols opposite each name they can be readily and easily referred to. We have found that the mnemonic method is much easier to remember and more satisfactory in operation than a numerical COSTS WITH STEAM AND ELECTRIC SHOVELS 437 system. It has been in use for some time and it is proving very satisfactory. STANDARD CLASSIFICATION OF EXPENSES Classification I. Main Classification of Expenses. . X Miscellaneous ^Overhead. F Field LnirpH- U Sub-contract | Classification II. Distribution of Classification I. L Labor directly productive. Lh Hourly labor. Lw Weekly labor. Lm Monthly labor. Li Incidental labor. F Labor superintending. M Material. Supplies. X Miscellaneous. Classification III. Distribution of Classification II. R Repairs -Maintenance. S Storage H Hire or rent T Transportation O Organization or preparatory X Miscellaneous. Charity or accidents B Bonus or discounts i Tt Legal and medical ^Incidental. P Publicity or advertising A Accident insurance t' Fire insurance Q Theft insurance G Bond to guarantee contract Classification IV. Application of Classifications II and III. E Equipment or plant. T Tools. B Buildings. C Cash capital. X Miscellaneous. Classification V. Field Processes. B Breaking (loosening). C Construction. D Dumping. G Grubbing. L Loading. M Mixing. Protection. R Ramming and rolling. Spreading. T Transportation. X Miscellaneous. Classif.cation VI. Type of work. C Concrete masonry. Earth. L Liquids. Brick and mortar. R Rock. W Woodwork. 438 HANDBOOK OF EARTH EXCAVATION We also give in this chapter some charts made up from our observations, which will be useful in helping to estimate the costs on steam shovel work. Rates of wages must be ascertained for the particular locality in which the work is to be done, and with reference to the condition of the labor market. It may be GRAPHICAL DIAGRAM SHOWING COST IN CENTS PER CU. YD^ OF MATERIAL HANDLED, PLACE MEASURE - DIRECT SHOVEL LABOR ALONE BEING CONSIDERED STANDARD BASIS RUNNER PER DAY $5.00 CRANE MAN " ' $3.60 FIREMAN t> $2,40 PITMAN ii tt $1.50 MISC. (DIRECT) .' " $1.60 REPORT NUMBERS Tig. 33. Diagram Showing Cost. TABLE OF RATES OF WAGES. DIRECT LABOR Occupation Runner . . Craneman Fireman Coalman . Pitman Bucyrus Shovels No. Obs. Minimum Average 41 $75.00 per month $135.00 per month 41 55 00 per month 96.00 per month 38 50 00 per month 62.00 per month 8 1.40 per day 1.47 per day .'. 39 1.40 per day 1.90 per day Maximum $175.00 per month 125.00 per month 87.00 per month 1.50 per day 3.50 per day noted that certain report numbers are quoted in these charts, the corresponding reports not being found elsewhere in this volume. In such cases the information is on file, but is not published in detail owing to objection on the part of the company or indi- vidual operating the shovels. COSTS WITH STEAM AND ELECTRIC SHOVELS 439 REPORT NUMBERS Fig. 34. Diagram of Time in Seconds for Complete Upper Swing. 440 HANDBOOK OF EARTH EXCAVATION Steam Shovel Work in Sand and Gravef. Most of this work is likely to be in a borrow pit, where a large area is to be excavated, and where the installation is of a semi-permanent nature. Many of the banks are very high, requiring few moves of the shovel, and in some cases, especially where there is some cementing material mixed with the sand or gravel, or when the 70 DIAGRAMS SHOWING IDLE TIME OF SHOVELS DUE TO WAITING FOR CARS IN PER CENT TOTAL WORKING TIME flT TimtfliTffi 11 iHllim 1111 1111111 tWORK IN SLAG. ROCK CUT FOR CANAL WIDENING. REPORT NUMDER3 Fig. 35. Diagram Showing Idle Time of Shovels. cementing is done by ice in the spring or fall of the year, heavy and dangerous land slides are possible. From an operating standpoint sand is an ideal material to handle, except when very fine and in heavy winds, in which cases a high pressure stream of water from a hose with spray attach- ment, if water be plentiful, will greatly help to keep the sand out of the eyes of the men. Sand in a freshly dug bank is COSTS WITH STEAM AND ELECTIUC SHOVELS 441 REPORT NUMBERS Material Min. Average Max. No. Obs. Sand- and gravel 18.2 40.5 67.6 5 Earth and drift 26.5 46.0 67.8 5 Clay 26.0 45.16 63.4 10 Iron ore 28.4 47.59 69.3 10 Rock 20.4 46.3 73.3 25 Fig. 36. Diagram Showing Actual Shovel Working Time in % of Total Time. quite often naturally moist. In railroad work a good deal of this material is loaded on flat cars with or without side-boards, and it is often difficult to make close estimates of the amounts handled. We have found it an excellent method to weigh the amount of material that will fill a half cubic yard box, at 442 HANDBOOK OF EARTH EXCAVATION average dryiiess, and then weigh several trains of cars of the material, which can easily and conveniently be done. From records obtained in 1898, average gravel used for railway ballast, fair quality, moderately clean, weighed 3,248 Ib. per cu. yd., rather dry, and the average flat car without side-boards con- tained 9.4 cu. yd. The length in a train of such average cars was 36 ft. center to center of couplers, so that when dumped from the train the ballast averaged 0.26 cu. yd. per ft. of track. This was sufficient to raise one track 5 in. Free running dry sand will not stand up so high in the bucket or on the cars as when it is quite wet or contains some little cementing material. Therefore, the best performance can be looked for where there is a little cement or water evenly dis- tributed in the bank. Report No. 1. Shovel No. 612, inspected September 11, 1909, Dune Park, Ind. The material was all of uniform size and exceptionally clean, sharp, white and rather small grained. The bank against which the shovel worked was fully 60 to 70 ft. high and sloped at about one on two. The material was loaded upon gondola cars supplied and spotted by the Lake Shore & Michigan Southern Railway. The shovel was of the usual 70-ton type with all steel dipper handle and boom, the latter being of the truss type braced on the sides. A 2^-yd. dipper was used. This, instead of teeth, had a long steel lip or " cutter blade," so that when filled its capa- city was increased to about 3^. yd. Water was taken from the KNICKERBOCKER ICE COMPANY. STKAM SHOVEL REPORT. EMUINF. CM U.A IMS. T. DELAYS .. A... 1VKU Dtr KTED K .CO. ! "'" REMARKS * TOTALS -' Fig. 37. Report Form for Steam Shovel Work. COSTS WITH STEAM AND ELECTRIC SHOVELS 443 ground by means of a pipe sunk therein and a pump on the shovel, which was digging to water level only. Cost keeping. The time sheet was made in duplicate and was sent to the main office, where the payroll was made up and the total amount charged to the job. The steam shovel report also went to the main office every day. This was made out by the steam shovel engineer, but was copied by the clerk to obtain a clean sheet. A facsimile of such a report blank is given in Fig. 37. OBSERVATIONS Weight 70 tons, shipping weight without coal and water Capacity of dipper 3.27 cu. yd., including lip Depth of dipper (water measure) 51 in. Depth of dipper including lip 8iy 2 in. Cubic yards excavated (place measure) in 8 hr 3,300 Cubic yards per car (place measure) average 21.2 yd. Per cent. Actual working 67.6 Spotting cars 0.7 Waiting for cars 22.6 Moving shovel 6.8 Miscellaneous delays, including 8 minutes clearing track 2.3 Total time under observation, 481 min. 100.0 DIRECT LABOR DISTRIBUTION Per day 1 runner $ 5.00 1 craneman 3.60 1 fireman 2.40 3 pitmen 4.50 3 spreaders 4.50 Watchman 1.50 Timekeeper 2.00 Shop engineer 2.00 1 machinist 3.00 1 car repairer 2.00 Total cost of labor per day $30.50 Cost per cu. yd., ct 0.93 Report IVo. 2. Shovel No. 1118, inspected July 16, 1909, at Kent, Ohio. This work was part of that undertaken in the relocation of the Wheeling and Lake Erie R. R. at Kent, Ohio, and was done by John B. Carter under contract. A prize of $5 was offered to the dinkey runner who made the best time spotting cars during the afternoon's work. OBSERVATIONS Material is fine gravel with occasional strata of sand. Ideal material to handle. Weather fair after heavy rain during night. Type of shovel Standard gauge 70 C Size of bucket 2% yd. 444 HANDBOOK OF EARTH EXCAVATION Length of shift 10 hr. Coal used 3% tons per 24 hr. Water used 300 gallons per hr. Narrow gauge track 3 ft., 55-lb. rails for cars. Kind and size of cars used K. & J., 4 yd. Kind and size of dinkey Vulcan, 16-ton Length of haul Max. 3,500 ft., min. 2,300 ft. Number of trains 3 Per cent. Actual working 58.9 Waiting for cars 7.4 Moving shovel 13.2 Miscellaneous delays (20.5) Coaling 1.2 Repairing track 1.1 Repairing track .9 Pulling track on dumps 17.1 Minor repairs .2 Total time under observation 100.0 Average number of cars loaded per day (average of 85 days) = 516 @ 4% yd. Average number of cubic yards loaded per day (average of 85 days) = 2,193. Standard basis 1 runner $5.00 1 craneman 3.6u 1 fireman 2.40 3 dinkeymen 7.80 3 brakemen 4.50 4 pitmen 6.00 9 dumpmen 13.50 1 dump foreman .2.00 1 pipeman 1-50 1 smith 2.50 1 smith helper 1.50 1 watchman 1-50 Cost of labor per day $51.80 Number of Ob- Time Study Reductions serva- Minimum Mean Maximum tions Min. Sec. Min. Sec. Min. Sec. Time for moving up, shovel idle 19 1 20 2 54 5 45 Time between moves, shovel working.. 20 7 35 12 23 14 Time between trains 21 .. 55 1 29 2 05 Time per train loading 36 6 07 6 52 8 10 Time per dipper 21 . . 16 . . 17 Number of dippers to move 20 24 .. .. 42.3 Number of dippers per train 36 24 .. .. 24.2- .. 26 Number of dippers per car 432 2.02 The total loading time of the contest was 215 min. 57 sec., and in this time 770 complete dipper swings were made, and 384 cars at 4 cu. yd. each were loaded. Shovel No. 1118 was moved back on standard rails 30 ft. in length, only 6 rails being used, and the method employed was as follows: COSTS WITH STEAM AND ELECTRIC SHOVELS 445 When the shovel had finished its cut, a track 90 ft. long was laid behind it joining the regular shovel track made up of short sections. The shovel was then backed to the end of this track, and as soon as it had passed off the first rail-length the rails were picked up by four men and thrown over the loading track. On this track stood a dinkey with a 6 by 8-in. piece fastened to its front end, and long enough to extend about 6 ft. from the side of the dinkey on the shovel side of the track. At the end of this was a piece of %-in. cable, wrapped securely around the timber, and with a loose end about 10 ft. long. At the loose end of the cable was a hook made of material small enough to be inserted in the bolt holes in the rail. When a rail was moved over toward the loading truck this hook was fastened to the rail and the dinkey then dragged the rail to the rear of the shovel. While the four men were moving the rails and the dinkey was dragging them, three other men were gathering up the ties and putting them in piles of three or four each, fastening them with chains. The ties were dragged by mule team to a place in rear of the shovel where they were spaced by two men and made ready to receive the rails. As soon as sufficient ties for a rail length of track were laid, the rails that had just been brought back by the dinkey were placed upon them and fastened to the rails on which the shovel stood, and were connected and spaced by four regular track bridles. The shovel then moved back one rail length and so left a rail length in front of its position uncovered, this being then torn up and moved back the rails by the dinkey and the ties by the mules. The force engaged included the Shovel engineer 1 Foreman Craneman 1 Mule team and driver Fireman 8 Men moving rails Dinkey engineer 5 Men moving ties Dinkey brakeman 4 Pitmen bolting track, etc. at a total labor cost of $46.60 per day. It took 1 hr. 10 min., to move the shovel back 300 ft. in this manner or .1167 of a day. 0.1 167 x $46.60 = $5.44 to move 300 ft., or 1.81 ct. per ft. Preparatory cost was $1,500; includes moving shovel 2,500 ft. from railroad tracks on practically same grade as bottom of pit. Distance of move in pit laterally for each bank averages 30 ft. for eleven moves. 446 HANDBOOK OF EARTH EXCAVATION ACTUAL RATIOS Water consumption, pounds 60,000 Coal consumption, pounds 7,500 = 8.00. Report A 7 o. 3. Shovel No. 611,. Inspected Sept. 14, 1909, at Gary, Ind. The shovel itself had no features that would distinguish it from any of the others of the 70-ton class, but the method of blocking up the rear trucks was different from the usual practice. These were raised 20 in. while the front ones were elevated only the usual 6 in. The reason given for this by the runner was that the boom " swung better." When swung loaded over the cars it could be stopped more quickly and would swing back in less time than when blocked evenly. The boom was of the truss type with lattice - side bracing, and both it and the dipper handle were made entirely of steel. Water was taken from the loco- motive. OBSERVATIONS Capacity of dipper 3 cu. yd. Area of section of face 755 sq .ft. Height of face 24 ft. to zero Cubic yards per car 21.1 place measure (average) Per cent. Actual working 35.4 Spotting cars 0.3 Waiting for cars 48.8 Moving shovel 5.1 Miscellaneous delays 1.3 Idle-engineer looking after fire 3.8 Pitmen loosening bank 0.2 Waiting for cars to pull out 0.4 Fixing valve on crane engine 1.1 Taking water 1.8 Taking coal 1.8 Total time under observation, 547 .min 100.0 THE SHOVEL CREW PAY ON STANDARD BASIS Runner $5.00 Cranemen 3.60 Firemen 2.40 4 pitmen 6.00 6 trackmen 9.00 Labor cost per day for excavating $26.00 Cubic yards loaded on day of observation 1,602 $26.00 Cost of loading per cubic yard (direct labor only), 1,602 = 1.62 cents per cubic yard. Steam Shovel Work in Earth and Glacial Drift. The pecu- liarity of this material for steam shovel work is that it varies COSTS WITH STEAM AND ELECTRIC SHOVELS 447 much more in consistency than sand and gravel, may be difficult to break up, and often contains boulders of considerable size. It is the usual practice to attack it with teeth instead of a steel lip on the bucket. When wet, the material is likely to stick to the bucket, and particularly to the bottoms of dump cars, making it difficult to remove in dumping, and being likely to dry or freeze into a hard cake. For this reason it is important to clean and scrape car bottoms at night. Because of the prevalence of boulders, which cause irregular loading of the bucket and of the cars, this material will not be likely to average quite as many yards, place measure, per car of the same size as will sand or " good " gravel. Fig. 38. 1%-yd. Bucket with 18-in. Lip Added, Increasing Capacity to About 2 Yd. Used on 45-Ton Shovel near South Bend, Ind. When the large boulders occur, necessitating the use of chains and hooks, or even mud capping with dynamite to reduce their size, the work is necessarily much delayed and the cost becomes excessive. Sometimes a good sized boulder may roH down the slope and injure one of the pitmen, who are therefore more cautious than when working in sand, and consequently slower. In estimating upon this material the ground should be gone over with care by the man who is to make the estimates, and a computation made of the number of boulders above the limiting size that are likely to be encountered. A shovel with large bucket 448 HANDBOOK OF EARTH EXCAVATION is advisable for this work, since the delays from boulders are thus minimized. Report No. p. Shovel No. 893, Inspected July 14 and 15, 1909, at Long Island City, N. Y. This shovel had standard gauge railroad car wheels, weighed seventy tons and was about three years old. It .had been over- hauled several times and was in good condition. It will be noticed under the " Labor Distribution " table that there were two more pitmen than is usual. The duties of the en- gineer consisted in superintending everything about the shovel in a general way and, in co-operation with the craneman, running the shovel. His word was law in anything connected with the shovel. The craneman operated the dipper engine and dumped the dipper. He also directly supervised the operation of moving forward, but on this shovel did none of the actual work. The pitman receiving $1.75 was a general handy man and was fore- man of the pitmen, although he did the same work as they. While the shovel was operating, the pitmen were engaged in taking^up the rails and ties behind it and carrying them to a convenient place ahead, so that they could be readily laid. The ties were thrown in front of the forward trucks, and as soon as the dipper dug high and far enough away, the pitmen laid the stringers and then rolled the ties into place so that as soon as the shovel was ready to move, all that remained to be done was to place and clamp them to the rails, and set the jacks. Under the head of " Time Study " will be found the percentage of the total time consumed in moving forward. As has been explained, moving the shovel forward is an inter- mittent process. So far as is possible, however, the move back to enter a new cut is made continuous. This necessitates an unbroken track behind the shovel. In this particular case it took all morning and part of the afternoon to thus clear the way and lay the ties and rails. The time required for such a process is of course dependent on the distance the shovel must be moved back and also upon the number of curves encountered. Great care should always be exercised in having the bridle rods in proper adjustment, especially on the curves, for otherwise the shovel will be likely to leave the track, causing annoying delays. Here, as will be seen in the " Time Study," the actual moving back occupied 106 min., and 48i/ min. were necessary to get things into running order after the backward journey. Coal for the shovel was brought in by the dinkeys, dumped near by, and carried from the dump by a laborer. For this purpose an ordinary nail keg was used, and by having the man keep count of the number of kegs, the consumption to within a COSTS WITH STEAM AND ELECTRIC SHOVELS 449 tenth of a ton was obtained. On the first day this amounted to 2.2 tons and on the second to 2.7 tons. In order to be able from time to time to tell whether any part of the work was costing more than it should, the engineer in charge had kept very close cost accounts, and he very kindly explained his methods. The timekeeper on this work had two books, using them al- ternately. He did not write in the names or the numbers of the men before leaving the office, but as he found the men on the work he jotted their numbers or names one below the other just as he came to them, starting with a new page every day. The following day this book was left in the office and the clerical force compared the timekeeper's record with the foreman's re- ports. If there was any discrepancy it was called to the time- keeper's attention and he looked into the matter. From these records the office force made up a daily statement showing the labor employed, the rate of wages, the amounts, and the nature of the work. Material used was kept account of by the amounts delivered to each machine or foreman, as shown by the storekeeper's daily report. From these reports the engineer himself made up the distribu- tion. This, however, did not follow any definite scheme such as the schedule employed by the Construction Service Company, but consisted in crediting to each item, such as grading, surfacing, mixing concrete, shovel No. 1, etc., its quota of labor and ma- terials used, and from these data the unit costs were computed by the engineer, so that no one else has access* to them. Super- intendence, insurance, interest, and other items that could not be charged directly to any one operation were distributed accord- ing to the percentage of the total labor cost involved. Superin- tendence had been found to be about 6 to 6^% of the labor cost. The cost and amount of coal, oil, and cotton waste supplied to any machine over a definite period was divided by the num- ber of working days and by the number of yards excavated or hauled to find the unit quantities and costs. Depreciation was not considered until the end of the job. With the exception of the foreman's reports and the daily statement of the time- keeper, no printed forms were used for this work. The general plan of the track layout, shown in Fig. 39 is the ideal arrangement for feeding cars to a shovel as, with wide awake signalmen and dinkey engineers and plenty of cars, there should be no more reason for losing time in spotting trains than in spotting cars, for as soon as a train is loaded and pulls out another follows right into its place, and by loading the end car first no time need be lost. With the exception of not always 450 HANDBOOK OF EARTH EXCAVATION having enough trains on hand, this is what would happen on this work, and when the trains did follow one another very little time was lost. This arrangement is particularly suitable when the number of moves of the shovel is a minimum for then the idle time of the dinkeys would be a minimum also. J* Fig. 39. Track Arrangement Shovel 893. Report No. 6. The total u run around " was 7,300 ft., 6,600 ft. and 6,300 ft., depending upon the dump, as indicated in the sketch (Fig. 39). The dinkeys weighed 18 tons each and the cars were the usual 4.17-yd. side dump cars. These cars hold about 3.6 cu. yd. when heaped full. No method of breaking was provided or needed. Per cent. Actual working 43.4 Spotting cars 0.0 Waiting for cars 20.4 Moving shovel 17.9 Idle time rain , 1.2 Repairing boom 2.8 Clearing track after blast 6.1 Miscellaneous time clearing bank 2.3 Blasting 0.4 Moving boulders 3.0 Boulder on track _. 1.5 Loosening bank * 0.7 Jacking up 0-3 Total time under observation, 600 min 100.0 1,705 cu. yd. per day during 1908. Standard Basis Second Day Runner I 5.00 Craneman 3.60 Fireman 2.40 1 pitman 1-75 8 pitmen 12.00 COSTS WITH STtiAM AND ELECTRIC SHOVELS 451 Standard Basis Continued 1 coalman 1.50 3 locomotive engineers 7.80 3 locomotive brakemen 4.50 1 switchman 1.50 4 laborers, blasting 6.00 1 foreman, blasting 2.00 35 laborers, 3 dumps 52.50 3 foremen, 3 dumps 6.00 1 superintendent 6.00 Total cost of labor per day $112.55 Cost of labor per cubic yard, cents 7.89 From the record which follows: Average cubic yards excavated per day during 1908 1,705 Average cost loading labor per day $24.75 Number cubic yards per day 1,705 = 1.45 ct. per cu. yd. Month *Janiiary *February March . . . April May June July August . . . September October . . November *December Total days worked 26 23 21 25 25 25 26 1 25 25 24 Actual No. days Number of worked less stormy days all delays 1 21.10 1 18.17 3 18.73 1 20.65 1 21.58 23.28 22.38 18.64 13.92 17.35 Total 246 7 195.80 9-hr, days during January, February and December. Steam Shovel Work in Clay. Clay is more susceptible to mois- ture than any of the other materials considered in this volume. It will stand with a nearly vertical face before excavation and can be dug very readily when fairly dry. When rather wet it is sticky and offers great resistance to the lifting motion of the bucket. With a powerful engine this is of no great disadvantage, since the resistance is smooth and does not rack the boom and shipper shaft. In the pit, however, the discomfort attendant upon working in this wet material is very considerable. To han- dle it wet with hand shovels is laborious, as it sticks to the bowl of the shovel and tries to take the shovel and the shoveler with it when cast. A hole or two punched in the bowl will often afford much relief to the men. This material containing prac- tically no voids, is very heavy, and, owing to its stiffness, a large amount in comparison with sand or gravel can be loaded upon a car. Ton for ton, it is economical to transport for this reason. 452 HANDBOOK OF EARTH EXCAVATION In wet weather it is apt to cling like flypaper to the car and delay the damping operation. When handled with a toothed dipper it is liable to get between the teeth in chunks and cling to them when dumping into the car, so that only a portion of the dipper load is released for each swing. This is very irritating to the men and expensive to the management. Report Ao. 11. Shovel No. Ill 9, Inspected July 15, 1000, at Kent, Ohio. OBSERVATIONS Material. Clay mixed with san.l with occasional sand pockets. When dry could be handled easily but when wet it was very gummy and stuck in dipper badly. Some quicksand. Type of shovel 70 C Bucyrus Size of bucket 2y 2 yd. Length of sh.ft 10 hr. Coal used 3 tons in 10 hr. Water used 3,500 gallons in 10 hr. Boiltr is cleaned once a month. Narrow gauge 3 track, 53-lb. rail. Kind and siie of cars used K. & J., 4-yd. Kind and size of dinkey Vulcan, 16-ton Length of haul Max. 2,700 ft., min. 2.000 ft, Number of trains 2 12 cars Cars figure 414 yd. each according to this record and monthly estimate for first three months. This shovel cut into right of way for several days and was then turned into borrow pit. The preparatory cost of cutting into right of way was $400 and to cut into borrow pit $1,200 more. Shovel was delayed from May 19th to May 26th, on account of right of way difficulties. Total preparatory costs and cost of delay were said to be $3,000. Per cent. Actual working 63.4 Spotting cars Waiting for cars 19.1 Moving shovel 13.6 Miscellaneous delays 3.9 Total time under observation, 362 min 100.0 From the records which follow: Number of carloads excavated per day (average of 36 days) 380 @ 4V 4 yd. Cubic yards loaded per day (average of 36 days) 380 x 4.25 x 90* 1,450 cu. yd. Place measure * 0.90 ratio of Water measure Standard Basis Runner $5.00 Craneman 3.60 Fireman 2.40 4 pitmen 6.00 COSTS WITH STEAM AND ELECTRIC SHOVELS 453 Dump foreman 2.00 7 dumpmen 10.50 2 brakemen 3.00 2 dinkeymcn 5.20 1 pipeman 1.50 1 watchman 1.50 Total cost of direct labor per day $40.70 Cost per cu. yd. (ct.) 2.81 Report No. 12. Shovel No. 843, Inspected July 10, 1909, at Cleveland, Ohio. This shovel was working during July on a deep cut on the L. S. & M. S. cut-off south of Cleveland, Ohio, where the line runs through Brooklyn. The finished cut was to be for a four-track line and the bench on which the shovel was working at the time was within 3 ft. of finished sub-grade. On the south .side-of the cut the excava- tion was to grade and one cut more was needed on the middle bench to finish the work. The remaining 3 ft. to the sub-grade, on the north side was to be taken out by hand. The shovel was to go through the cut once more on the cen- ter line, or a little to the left of it, so as to take the 7-ft. heading to grade, and as much of the 3-ft. cut on the north side as possible. Fig. 40. Typical Cross Section. Material. The material was dry clay and disintegrated shale. When the dipper was run into the bank the material broke up into fine flake spalls almost like small shells, and as it was per- fectly dry it could be handled with the utmost ease. When the shovel was near the bank after moving up, the dipper could pene- trate to half its depth by inertia alone before the crowding en- gine was started, thus insuring a full dipper at every swing even though it might be brought but half way up by the hoisting en- gine. The dipper was dumped easily and was completely emptied at each dumping. When an attempt was made to heap a car, ma- terial was almost sure to be lost, as it was so light and flaky and so lacked cohesion that it would run over the side. For the same reason the dipper had to be spotted very carefully before it was dumped. In spite of whatever care the shovel runner exercised in dump- ing his dipper and the brakeman in spotting his cars, the track had to be cleaned after each train pulled out. This, of course, 454 HANDBOOK OF EARTH EXCAVATION was done by the pitmen, and often, when moving up occurred between trains, they were able to get the track clear and look after their regular duties as well. When moving up the shovel, a 2-in. pipe was used to swing the jack blocks clear of the ground instead of the ordinary wooden pole. This pipe was held in a bracket attached to the jack arm and had a collar about 4 in. from its end, which kept the chain that suspended the jack block from slipping along the pipe. This pipe was held by the bracket and was always in place, there be- ing little danger of its breaking or splitting, as is often the case with wooden poles. The average haul was about three miles over very rough track. Three standard railroad locomotives were used. The cars were the most modern type of Western " air dumps " of 12-yd. capacity. They were built in two sizes, there being 40 cars with bodies 18 ft. 9 in. long and five cars with bodies 26 ft. in length. All were double truck, two-side dumps with wooden bodies. Trains were composed of 15 cars each. Ten men worked on the dump. The material was unloaded on one side over a bank about 40 ft. high. When the track was not near the edge of the bank a spreader was used. This consisted of a steel scraper plate with one end hinged on the trucks of a flat car and the outer end supported by a line from a block on the floor of the car. The spread and depth of cut could be regulated by one man on the car, but often the operator of the spreader was helped by the brakeman of the train. The regular dump train engine was used in operating the spreader. OBSERVATIONS Shovel 1 70-ton Bucyrus Size of bucket 2% yd. Length of shift 10 hr. Coal used 2y 2 to 2% tons per day Water used 6,000 gallons per day Standard gauge track; 55-lb. rails. Kind and size of dinkey Standard locomotive Length of haul 3 miles Number of trains 3 of 15 cars each Note. The bank was dry and the pit seemed to need no draining. Material was easy to handle, and a much larger dipper could have been used. Four-yd. cars had been employed previous to the 12-yd. cars and it was found that two swings of a 2%-yd. dipper filled these cars completely; seven swings of a 2%-yd. dipper filled the 12-yd. cars completely. Pit crew was composed of rather green men. The runner said he could move up (6 ft.) in 1 01 1% min. in such a pit with a good crew. Per cent. Actual working 57.5 Spotting cars Changing trains 9.1 Moving shovel 28.3 Shovel taking water 2.2 Miscellaneous delays 2.9 Total time under observation, 396 min 100.0 COSTS WITH STEAM AND ELECTRIC SHOVELS 455 Standard Cost of Direct Labor (Loading) Per Day basis Eunner $5.00 Craneman 3.60 Fireman 2.40 6 pitmen 9.00 1 coal passer 1.50 $21.50 Number of carloads excavated on day of observation 90 Cubic yards loaded on day of observation, 90 x 12 x 0.83 900 Based on the performance observed the cu. yd. loaded per 10-hr, day 900 x 600 min. 1,360 cu. yd. 396% min. Cost of labor per day 21.50 = 1.58 ct. per cu. yd. Number of cu. yd. per day . 1,360 Report A 7 o. 13. Shovel No. 666, Inspected July 17, 1909, at Kent, Ohio. This work was part of that done for correction of line on the W. & L. E. R. R., near Kent, Ohio. Before cutting in, this shovel, a 70-ton Bucyrus, was moved 1,600 ft. The shovel crew, 16 men, foreman and 1 team were en- gaged in this work for 8 hr., at a total cost of $34.00, or 2.12 ct. per ft. moved. Per cent. " *i ! * '>'>j4 in. x 8 in. were used under this shovel but 472 HANDBOOK OF EARTH EXCAVATION to each 6-ft. length of rail there was one 8 x 10-in. tie. On this tie plates were fastened, at the proper distance from each end, each with two angles attached. Upon moving up each time the 6-ft. rail section could be readily slipped into the groove, as shown in sketch, and pins slipped into holes to secure it. Directions for Moving Shovel. In order to systematize the various operations in moving a steam shovel and thus reduce the cost to a minimum, the order in which these movements should be made is given. Fig. 48. Diagram of Shovel and Track. (1) Just before moving, the last dipperful will be taken from B. As this dipper is being filled, runner gives one whistle signal to the pit gang (six men in pit). Two men go to JA and two to JB, and one man goes out to F on the rail clamp and one to H on the rail clamp. (2) As soon as the dipper has swung to the left of the center (M) JB is loose, and one of the men there runs up the screw. (3) One man at JA puts his pole over the jack and gets ready to raise his jack block. Meanwhile the dipper has dumped at A. (4) Other man at JB now raises his jack block and is ready to move. (5) Dipper swings to the right far enough past M to take the weight off of JA, which is immediately screwed up and the block raised. (6) While runner is throwing in his moving clutch, one man at F is knocking loose rail clamp, and one man from JA and one from JB pick up the chock and carry it forward to its new position. (7) Runner now moves shovel ahead; H knocks the clamp loose. F is meanwhile putting his clamp on in the new position. (8) As soon as the shovel strikes the front chock, H puts his clamp on. The bucket is in the center position for this movement. (9) The jackmen JA and JB immediately screw down their jacks, and the first man to get his jack down gives signal to runner, who takes first bucketful on his side. This enables man on either side to get his jack well screwed down before bucket crosses center line again, working away at full speed. Shovel now works away even if a little out of level. It can be leveled up by runner telling JA or JB to loosen a little, the opposite man screwing down on the next half swing. Cost of Moving Steam Shovels. In Engineering News, May 21, 1903, the author published data on the cost of constructing X COSTS WITH STEAM AND ELECTRIC SHOVELS 473 part of the P., C. & W. R. R. in a mountainous portion of Ohio. The cost of moving large and small steam shovels was as fol- lows: A 65-ton Bucyrus shovel was moved a distance of 1^ miles. One mile was over a rough road and one-half mile across a field having a slope of 15. The work occupied 8 days, and cost as follows: Steam shovel crew $160 Foreman at $3.50 28 8 men at $1.50 96 1 team at $4 32 Total at $210 per mile $316 This same shovel was also moved 6 miles in 30 days, and again 14 mile down one hill, across a valley to another hill in 23 days, at a cost of about $40 per day. A 35 -ton Vulcan traction shovel was moved over 18 miles of rough road, the last mile being up a steep hill and over field. The time occupied was 18 days, and the cost about $35 per day and $35 per mile. According to Mr. C. T. Montague, in Engineering and Contract- ing, Apr. 23, 1913, a 70-ton Bucyrus steam shovel was moved 24.2 miles in 8 days over country roads and fields during March when the average temperature was 10 F. The regular wheels of the machine were removed and replaced with trucks of the ordinary house-moving type, consisting of three units of four wheels, each mounted on false bolsters. The shovel was drawn by a 32-hp. steam tractor and a 25-hp. tractor, with a 5-ton motor truck to help out on the starts. Many deep ravines and sharp turns were encountered but no difficulty was experienced except from the scarcity of water. Only 4 laborers were employed. The cost of moving was $48 per mile. Victor Windett in Proceedings of the Western Society of Engi- neers, Jan. 7, 1911, gives the following: The cost of moving a shovel under its own steam on rails from a railroad-siding to the site of the work in Chicago, for a haul of something over a mile, was at the rate of 6.5 ct. per lin. ft. In New Orleans a 25-ton shovel was moved 13,000 ft. at the rate of 260 ft. per hr. The work required 5 days' time, as follows: Removing and resetting crane $100 Labor, teams, coal and water 175 Cutting electric wires and general expense 75 Total $350 Cost per lin. ft. to move 2.8 ct. 474 HANDBOOK OF EARTH EXCAVATION A team was used to drag ahead the pieces of track over which the shovel had moved. Cost of Moving a Shovel by Motor Trucking. Everett N. Bryan in Engineering Record, June 17, 1916, gives the following record of cost of moving a 60-ton Marion shovel 32 miles, from La Grange to Modesto, Calif. The entire time was 61 days, using a small crew of men. This time could have been cut in half with a larger crew. Before moving, the shovel stood in a pit 50 ft. deep. A road 750 ft. long had to be graded out of the pit, 200 ft. of which was up an 18% grade. The shovel pulled up this grade with its own power using a wire rope tackle. Then it was dis- mantled and hauled in nine loads by a 5-ton motor truck using a trailer. The heaviest of load was 10.5 tons, consisting of the main frame with decking attached, 10 x 35 ft. The cost was as follows: if. r'iiifti - ;.>.-,) J:MV--'l -KV, ];>()<{- lit.; ;-,ii - ' -p,...ij." Dismantling shovel ... $ 71.10 Reassembling shovel 194.45 Lumber and tool rental 50.00 " " haulage 46.40 Breakages 20.00 Grading 750 ft. of road 56.62 Loading assistance 34.94 Unloading assistance 11.40 Total $ 484.91 Moving shovel 750 ft. out of pit 218.18 Total $ 703.09 //K:; /or 1 ', -/'i .?'U*.tefii y^In'i Moving shovel 300 ft. across bridge 37.76 Hauling shovel 32 miles 441.76 Grand total $1,182.61 The items of loading and unloading assistance relate to wages paid to others than the motor truck driver and his, helper while loading and unloading. The item of moving across a bridge relates to hauling some of the heavy parts on wagons by cable across a light bridge. Cost of Railway Work. Engineering and Contracting, May 30, 1006, gives the following: In 1895 considerable steam shovel work was done by the Ann Arbor R. R. in the betterment of its grade and line. The railroad was a single track line upon which it was neces- sary to keep both freight and passenger trains moving without delay, and some of the work was made more expensive by the fact that from 18 to 28 trains per day had to be contended with. A portion of the work was ballasting, the haul from the gravel pits ranging from 10 to 50 miles. On grade reductions, the haul COSTS WITH STEAM AND ELECTRIC SHOVELS 475 ranged from one to four miles. The steam shovels used were track shovels, with 11/4 cu. yd. dipper. Shovels Nos. 1 and 2 were the Bucyrus steam shovels, and were new; shovels Nos. 3 and 4 were Marion steam shovels. The cost figures cover the cost of the loading, transporting, unloading of material and placing it under the track, but make no allowance for rental of plant, locomotive or cars, or per cent, for deterioration of plant. The rates of labor the season of 1895 were about as follows: Laborers, $1.15 per day; track foremen, $65 per month; work train conductor, $0.25 per hr. ; brakemen, $0.17% per hr.; shovel enginemen, $100 per month and % ct. per yd. bonus on all material moved above a 750 yd. per day average. In sand the cost ranged from 7 to 17 ct. per cu. yd., the average being about 10 ct. In clay the range was 10 to 18 ct., the aver- age being 14 ct. Cost of Railway Grading. In Engineering News, Dec. 31, 1903, D. J. Hauer gives some data on steam shovel work, a portion of which we have abstracted. The work was during November, 1901, and was the best done in 11/2 years by three shovels in North C'arolina. These shovels were employed in regrading a railroad track ( see Fig. 49 ) , the cut being 1,200 ft. long. The earth to the right of the old track was first excavated to the grade of that track, the shovel loading Fig. 49. Cross-Section of Railway Cutting. into cars on the old track. The solid rock made progress slow, 29,800 cu. yd. of earth and 1,200 cu. yd. of rock being excavated between Sept. 5 and Oct. 31, working day shifts only, except during the last week when two night shifts were worked. During November, day and night shifts of 12 hr. each were worked, the shovel excavating at the left of the main track and using the old track as a loading track. The material could be classed as average earth, being red clay 476 HANDBOOK OF EARTH EXCAVATION and mica. The bank was shot with powder. The width of shovel cut from center of loading track at the widest point was 51 ft.; the minimum width was 35 ft. The height of the breast was 40 ft. The shovel used was a 65-ton Bucyrus, equipped with a 2}-yd. dipper. A dynamo furnished current for electric light for night work at times. The boiler also furnished steam for a 3%-in. rock drill and a 4-in. steam siphon and 1^-in. jet for pumping. Gasoline lamps were used on the dumps. The shovel had a clear lift of 17 ft., cut 27 ft. from its center and dumped 24 ft. Two trains of 15 cars each, drawn by 16-in. cylinder locomotives served the shovel. The cars used were Kilbourne & Jacobs, 6-yd., two-way, dump cars; six cars in each train being equipped witli brakes. The cars were of 6 cu. yd. water measure capacity, the actual contents as measured in place being 5 cu. yd. The dumping gangs consisted of 1 foreman and 20 men on one dump 1 mile distant, and 1 foreman and 12 laborers on a tem- porary trestle dump 2.5 miles distant in the other direction. The former dump was used only during the day time and the latter day and night. A temporary trestle was constructed with bents at 14-ft. centers. The mud blocks, sills, posts and caps were of round timber, the braces of 3 x 8-in. sawed pine, and the stringers of 10xl2-in. sawed pine. The stringers were used again. This trestle cost 2 ct. per cu. yd. of embankment. Some delay was caused by the necessity of clearing the loading track for 20 to 30 regular trains per day. Mr. Hauer estimated that fully 40% more work could have been done had the track been clear at all times. The cost of the plant used was about $27,000. The total yard- age moved during the month was 56,120 cu. yd.; the daily average was 2,160, or 1,080 cu. yd. per shift. The cost of the work during November was $7,070 or 12.6 ct. per cu. yd. exclusive of interest and depreciation. The cost of moving 31,000 cu. yd. during September and October was $7,000, or 22.6 ct. per cu. yd. The rails, ties, switches, and track fastenings were furnished to the contractor by the railroad company, the parts lost and con- sumed being paid for at market prices. The cost per month was as follows : 1 engineer in charge $ 150 1 bookkeeper 65 2 clerks 85 2 telegraph operators board 30 1 watchman 35 2 cooks and 2 helpers 165 1 superintendent 140 1 night superintendent 90 Total general $ 760 COSTS WITH STEAM AND ELECTRIC SHOVELS 477 2 shovel enginemen $ 280 2 cranemen 180 2 shovel firemen at $2.25 per day 59 4 pitmen at $1.25 130 6 pitmen at $1 166 4 blasters at $4.25 , Ill 120 kegs of black powder at $1.25 150 Dynamite, exploders, etc 65 Total loading force $1,131 4 locomotive enginemen $ 360 4 firemen 160 4 conductors 300 8 flagmen at 208 1 switchman at $1 26 1 car oiler at $1 26 Total handling forces $1,080 1 inspector . . $ 40 1 day dump foreman at $3 78 20 day dump laborers at $1 520 1 day and night dump foreman at $3 130 24 day and night dump laborers at $1 624 Total dumping forces $1,392 Total track force $ 338 1 foreman at $2 $ " 52 10 laborers at $1 260 1 blacksmith at $3 78 1 blacksmith helper at $1.25 32 3 bays at 75 ct 59 Total miscellaneous force $ 481 Oil, gear shield, waste, packing $ 110 Torpedoes, fuses, etc 13 262 tons coal at $3.25 851 Repairs to shovel, engines, and cars 285 Trestle (36,000 cu. yd. at 1% ct.) 630 Grand total, 56,120 cu. yd. at 12.6 ct , $7,071 " ' i)'f i'*J : 1O< T l fc * *"* i *rn f-V^"Xf -Qfir * fc^T Cost of Filling a Trestle. Engineering and Contracting, May 9, 1906, gives the following: Henry H. Carter gives costs of steam shovel work, begun March 13, 1884, near Boston. The material excavated was fine gravel and sand which was used to fill in a trestle 1,700 ft. long across a lake. The cost of the trestle is not included in the following record, but the cost of laying track to the trestle and of laying a double track on the ties already on the" trestle is included. All told there were 6,700 ft. of single track, laid with 35-lb. rails. The gravel pit was located 3,700 ft. from the middle of the trestle, making the haul average % mile. 478 HANDBOOK OF EARTH EXCAVATION The gravel was measured in the pit before loading, and the total amount moved was 59,010 cu. yd. It was found that 1 cu. yd., measured in the cut, or pit, made 1.16 cu. yd. measured in the cars. The contractor's plant consisted of a steam shovel, two loco- motives, 14 dump cars, each holding 2% cu. yd. car measure, and 16 dump cars holding 1.85 cu. yd. each. For a time a small shovel was used, and its average output was 300 cu. yd. a day, including the days consumed in setting up and shifting plant. However, most of the work was done with a large shovel which averaged 582 cu. yd. per day, including setting up and shifting time. Ct. per Loading ($4,521, or 7.6 ct. per cu. yd.) cu. yd. Foreman, 100 days @ $4 0.7 Engineman, Ii2 days @ $4 0.8 Craneman, 122 days @ $3.50 0.7 Fireman, 123 days @ $1.75 0.3 Laborers, 574 days @ $1.50 1.5 Rent of small shovel, 51 days @ $9 0.8 Rent of large shovel, 75 days @ $13 :. 1.6 Repairs on small shovel 0.2 75 tons of coal for shovels @ $6 0.8 Oil and waste for shovels 0.2 Hauling ($3,639, or 6.2 ct. per cu. yd.) Foreman, 10 days at $4 0.1 Engine drivers, 229 days @ $2.50 1.0 Firemen. 216 days @ $1.75 0.6 Brakeman, 105 days @ $1.50 0.3 Icecutter, 15 days @ $1.50 0.0 Rent of 2 locomotives and trains, 235 days @ $7 2.8 120 tons of coal @ $6 1.2 Oil and waste 0.2 Trackwork ($1,492, or 2.5 ct. per cu. yd., Foreman, 10 days @ $4 0.1 Foreman, 95 days @ $2 0.3 Blacksmith, 125 days @ $2 0.4 Laborers, 638 days @ $1.50 1.6 Loss of tools 0.1 Dumping ($799, or 1.3 ct. per cu. yd 1 .) Foreman, 32 days @ $2 0.1 Laborers, 490 days @ $1.50 1.2 Miscellaneous ($3,420, or 5.8 ct. per cu. yd.) Superintendent, 60 days @ $6 0.6 Foreman, 12 days @ $4 0.1 Engineman, 10 days @ $4 0.1 Craneman, 10 days at $4 0.1 Blacksmith, 128 days @ $2.50 0.5 Laborers, 105 days @ $1.50 0.2 5 tons of coal @ $6 0.0 Blacksmith shop 0.2 Transportation of plant 2.6 Loss of tools and interest on value 0.3 Loss on rails, ties, etc .. 0.8 Blacksmith supplies Jiiuw,u..- 0.3 Grand total .. . 23.4 COSTS WITH STEAM AND ELECTRIC SHOVELS 479 Summarizing, we have: Ct. per cu. yd. Labor, loading 4.0 Rental of shovels, and repairs 2.6 Coal, % ton per day per shovel : .. 0.8 Oil and waste for shovels 0.2 Labor, hauling 2.0 Rental of locomotives and train 2.8 Coal, (V 2 ton per day per locomotive) . ... 1.2 Oil and waste for locomotives 0.2 Labor, tracklaying, 1^4 miles 2.5 Labor, dumping 1.3 Labor, installing shovels, etc 0.5 Blacksmithing 0.5 Blacksmith shop 0.2 Blacksmith supplies 0.3 Transportation of plant 2.6 Depreciation of small tools, rails and ties 1.1 General superintendence 0.6 Total 23.4 Cost on Railway Construction. S. T. Neely, Assistant Engi- neer, Southern Ry., in Engineerng News, Aug. 9, 1906, gives the cost of grade reduction work as follows: Cost of Equipment: 165-ton shovel $10,000 3 engines at $2,200 6,600 20-12-yd. dump cars 14,000 1 Jordan spreader 2, 400 Extra parts 1,000 Tools (jacks, shovels, bars, etc.) 1,000 Total ,^^^?. f ^.^.\.\'.'l:TJ^. M .J $35,000 * Annual Charges : Interest at 6'/ r $ 2,100 Renewals in 5 years 7,000 Total per year $9,100 Total per day $ 25 Daily Operating Cost per Working Day: 2 foremen at $3.75 $ 7 50 2 timekeepers at $2.35 4.70 1 shovelman at $5 5.00 1 craneman at $2.50 2.50 1 fireman at $2.25 2.25 1 watchman at $2.25 2.25 6 pitmen at $2 12.00 30 dump track raises at $1.75 52.50 13 track men at $1.75 22.75 3 locomotive men at $3.50 10.50 3 firemen at $^ . 6.00 3 brakemen at $2.50 7.50 1 conductor at $4 4.00 3 flagmen at $2 6.00 1 car repairer at $2 2.00 1 blacksmith at $3.50 3.50 1 blacksmith helper at $2 2.00 1 superintendent at $5 5.00 1 telegraph operator at $2 2.00 Total daily pay roll $159.95 480 HANDBOOK OF EARTH EXCAVATION Interest and renewal $ 25.00 2 tons coal for 3 engines at $2 12.00 2 tons coal for shovel at $2 4.00 Waste and oil at 75 ct. per machine 3.00 10,000 gal. water at 50 ct. per 1,000 gal 5.00 Total fuel and water $49.00 Total per working day $209.00 Non-Working Day Expense: 2 foremen at $3.75 $ 7.50 2 timekeepers at $2.35 4.70 1 shovel engineer at $5 5.00 1 craneman at $2.50 2.50 1 fireman at $2.25 2.25 1 watchman at $2.25 2.25 3 locomotive engineers at $3.50 10.50 3 firemen at $2 6.00 1 conductor at $4 4.00 1 superintendent at $5 5.00 1 telegraph operator at $2 2.00 Labor of ditching, etc., 20 hr. at 0.175 3.50 $56.20 Interest and renewals 25.00 Fuel and oil for 1 engine 5.00 Total non- working day expense $86.20 Cost per month: 20 working days $4,180 10 non-working days 862 Total per month $5,042 The average haul was 12,000 ft. Two trains of ten 12-yd. cars \were hauled by two locomotives, the third locomotive being employed in pulling the spreader, getting water for the shovel, switching, etc. Loading consumed 35 min. for 10 cars loaded by 6 or 7 dipper- fuls each, and dumping and latching occupied 5 min., giving a running time to the dump and return of 15 min. Due to de- lays only 140 cars or 1,540 cu. yd. were loaded per day, giving a monthly output of 30,800 cu. yd. A car held 11 cu. yd. place measure. The total cost of the work was as follows: Per cu. yd. Excavation 3.6 ct. Hauling 6.7 ct. Dumping and raising track 4.7 ct. Spreading 1.4 ct. Total 16.4 ct. Steam Shovel Work on Grade Reduction. Cost data on steam shovel work in grade reduction are given by John C. Sesser in Engineering and Contracting, Jan. 2, 1907. The work was done during the season of 1906, by company forces and equipment. The two pieces of work for which costs are given were the Big COSTS WITH STEAM AND ELECTRIC SHOVELS 481 Shoal Cut Off and the Little Shoal Cut Off, both located on the Beardstown to Centralia Division of the C., B. & Q. Ry. The Big Shoal Cut Off was a change of alinement and grades between Sorento and Reno, 111. On this cut off there were 318,711 cu. yd. of earth to be moved, of which 251,711 cu. yd. were steam shovel work. On this work two temporary trestles were built, having a total length of 2,961 ft. and an average height of 40 ft. The material for the embankment was hauled from the north, an average dis- tance of 1^ miles. The average depth of cut was 15 ft. The material handled was wet clay. On account of numerous springs encountered, both material and steam-shovel pit were very wet, which delayed this work to some extent. At times the clay would leave the dipper in chunks as large as the dipper itself. This made the dumping of cars from the high trestle rather dangerous and necessitated the locking of the cars to the trestle before they were dumped. The work being entirely separated from the main line, bunk houses were built for the men employed. Board was furnished the men for $3.75 per week by the boarding contractor*. Water was supplied to the shovel by a 2-in. pipe line, laid on the ground outside of the digging line. At every hundred feet this pipe line had a " T " with a tap, and by means of a long rub- ber hose water could be supplied the shovel at all times, thus avoiding the usual delay of siphoning water wlijch, in double- shift work, is an item worth consideration. This pipe line was also extended to the cook and bunk houses, thus supplying water for cooking and washing purposes. The temporary trestle built was designed to carry a loaded train of 5-yd. dump cars before being filled, and the engine in service only after the trestle had been filled. Each bent con- sisted of two piles, bracing and cap. Second-hand material was. used throughout, with the exception of the bracing. Two 8 x 16-in. stringers were used per span, which were built 13 ft. The stringers were recovered, the balance of the material buried in the embankment. The equipment used on the Big Shoal Cut Off work consisted of the following: One 65-ton Bucyrus stealn shovel; 2 switch engines (Class K) , weight on drivers, 30 tons; 43 5-yd. dump cars, and 1 Jordan spreader. All of the equipment except the Jordan spreader was second-hand. The second-hand value of this equipment was as follows: Value Shovel $5,000 Engines 4,400 Dump cars 5,052 Spreader 1,800 482 HANDBOOK OF EARTH EXCAVATION The Little .Shoal Cut Off work was a change of alinement and grades between Ayers and Durley, 111., the work necessitating the handling of 188,240 cu. yd. of material. The material handled was about 40% hard pan, it being about as hard a material as the shovel could dig without resorting to blasting. The pit was wet. The material was hauled an average distance of ^ mile and was dumped from a temporary trestle constructed for that purpose. This trestle had a total length of 2,142 ft. and an average height of 35 ft. On this work both shovel and engines were handled over 6% grades and 16 curves very easily. The equipment used in the Little Shoal Cut Off work was as fol- lows : One second-hand 65-ton Bucyrus steam shovel, 2 second-hand switch engines (Class E), weight on drivers, 30 tons; 36 second- hand 5-yd. dump cars; 1 new Jordan spreader. The second-hand value of this equipment was as follows: Value Shovel $5, 000 Engines 4,400 Dump cars 4,230 Spreader 1,800 It is interesting to note the cost per yard in place was the same on both jobs. While the equipment and organization were, in a way, about the same at both places, the material handled and the general layout of the work were very different. The organization of the working forces were the same in both cases, the following being the forces engaged on the Big Shoal work: Day Shift : Per month 1 general foreman ../... $118.50 1 steam shovel engineman 125.00 1 steam shovel craneman 1 steam shovel fireman 55.00 6 steam shovel pitmen, 19 ct. per hr. 1 conductor .......':_. 2 brakemen 69.00 2 enginemen $4 per day. 2 firemen, $2.40 per day. 1 track foreman iJ.W 1 assistant foreman, 10 ct. per hr. 10 laborers dumping cars, 16 ct. per hr. 38 laborers on track, at 16 ct. per hr. 1 watchman .00 1 timekeeper *'2! 1 pumper Night Shirt: 1 steam shovel engineman ^''-JJ 1 steam shovel craneman ..;,.y... f 1 steam shovel fireman 6 steam shovel pitmen, 20 ct. per hour. 1 conductor 2 brakemen 2 enginemen, $4 per day. COSTS WITH STEAM AND ELECTRIC SHOVELS 483 2 firemen, $2.40 per day. 1 assistant track foreman , 8 laborers, $1.75 per day. 1 watchman, $1.75 per day. 1 lightman, $1.75 per day. /fib ,.., Cost General foreman per Day: Labor ........ $ 2 28 Supplies Total $ 2 28 Steam shovel service 22 09 $ 5 50 27 59 Engine service 22 08 9 00 31 08 Car repairing . 4 40 4 40 Dumping cars 19 00 1900 2 88 2 88 Assistant track foreman 2 11 2 11 62 70 62 70 Timekeeper 1 73 1 73 1 73 65 2 38 Watchman 160 1 60 Total $142.60 $15.15 $157.75 Cost per Night: Labor Steam shovel service $ 22.69 Engine service . . Assistant foreman Dumping cars ... Lighting Pumping Watching 22.08 2.11 14.00 1.75 1.73 1.75 Supplies Total $ 5.50 $ 28.19 9.00 31.08 2.11 14.00 2.34 .70 2.43 1.75 Total $66.11 $17.54 $83.65 Total day and night $208.71 $32.69 $241.40 The prices at which supplies were bought were as follows : Valve oil, 50 ct. per gal.; black oil, 18 ct. per gal.; signal oil, 34 ct. per gal.; kerosene, 10 ct. per gal.; gasoline, 17 ct. per gal.; shovel and engine coal, $1.48 per ton on Little Shoal Cut Off work, $1.50 on Big Shoal Cut Off; waste, 6 ct. per Ib. For the sake of comparison of the two jobs Mr. Sesser's figures are arranged as follows: Little shoal cut off May 21 Sept. 30 May 22 Sept. 30 Days steam shovel on work 190 133 Nights steam shovel on work Days worked by steam shovel Big shoal cut off Date shovel commenced work Apl. 27 Date shovel completed work Nov. 2 Date shovel commenced night shift June 20 Date shovel completed night shift .'. . Oct. 26 190 129 140 88 Nights worked by steam shovel Total days worked by steam shovel (10-hr, shift called a day) Shovel laid up due to rain and Sundays (shifts) Shovel delayed, moving and shovel failure (shifts) . . . Waiting for grading of temporary track (shifts) Percentage of 199 days of shovel service delayed Total car output, day shift .... v . v ,. . . 47,682 228 57 23. 11 199 8 4 484 HANDBOOK OF EARTH EXCAVATION Big shoal Little shoal cut off cut off Total car output, night shift 27,377 23,116 Cubic yards handled, day shift 160,121 105,818 Cubic yards handled, night shift 91,590 82,422 Cubic yards per car 3.35 3.56 Cubic yards per day (10-hr, shift) 1,104 946 Percentage of night shift output to day shift output 84% 78% The cost of the work is shown in the following tabulations, all yardage being cross-section measurements. The progress of the work in the Big Shoal Cut Off from May to Oct., inclusive was 251,711 cu. yd. On the Little Shoal Cut Off 188,240 cu. yd. were moved from May to Sept. inclusive. COST OF STEAM SHOVEL WORK Big shoal Little shoal Equipment: cutoff cutoff Steam shovel, depreciation at 10% $ 500 $ 500 Engines, depreciation at 5% 200 220 Dump cars, depreciation at 10% 505 423 Spreader, depreciation at 5% 90 90 Total $ 1,315 | 1.233 Cost per cu. yd 0.005 0.006 Bunk Houses: Material $ 757 $ 757 Labor 388 310 Total $ 1,145 $ 1,067 Cost per cu. yd 0.004 0.005 Water Supply: Material $ 191 $ 311 Labor 81 300 Total $ 272 $ 611 Cost per cu. yd 0.001 0.004 Shovel Work, Labor: Shovel service $ 6,228 $ 5,360 Engine service 6,417 5,303 Car repairs and blacksmithing 771 514 Lighting 185 203 Dumping cars 4,265 3,149 Total $17,867 $14,529 Cost per cu. yd 0.071 0.077 Shovel Engine and Car Supplies: Valve oil $ 184 $ 84 Black oil 90 108 Signal oil 17 26 Kerosene 95 366 Gasoline 128 146 Coal for shovel . ..,,;,; 1,539 1,629 COSTS WITH STEAM AND ELECTRIC SHOVELS 485 Big shoal Little shoal cut off cut off Coal for engines .. 1,982 1,200 Waste . 48 48 Total $4,483 $3,607 Cost per cu. yd ................................. 0.018 0.019 Temporary trestle ................................... $JM)08* I 3,853* 0.031 Cost per cu. yd ................................. 0.050 0.042 Supervision and engineering ...................... $ _ 610 $ _ 487 Cost per cu. yd ....................... -. ......... 0002 0.003 Grand total ................................. $47,140 $35,205 Total cost per cu. yd ........................... 0.187 0.187 * Cost per lineal foot on Big Shoal work: Labor, $1.30; material, $1.74; total, $3.04. On Little Shoal work cost per lineal foot was: Labor, $1.22; material, $1.51; total, $2.73. t On Big Shoal work, labor cost was $11,582, and value of track supplies, $7,339 ; depreciation on latter and actual cost amounted to $8,856, making total cost of track work, $12,238. On the Little Shoal work, the labor cost was $6,673, and value of track supplies, $6,480; depreciation and actual cost on latter amounted to $1,144, making total cost track work, $7,817. Mr. Sesser states that the limits to which a shovel will work is a most important consideration in planning and estimating work of this kind. It is not economy to work the shovel to its ex- treme limit in lift and reach. The shovel on this work at times loaded the 5-yd. cars on a loading track 9 ft. higher than the shovel track, with the track centers 22 ft. Loading at such height is very slow work and is liable to wreck the cars badly on account of the lack of clearance for the dipper after emptying. When there is more than one cut to be made and where time is the all important factor, 7 ft. difference in elevation between the shovel and loading tracks allows rapid work and gives better results. In laying out steam shovel work considerable can be saved at times by taking advantage of the natural conditions of the work as they exist. The track arrangement and the future track arrangements as the work progresses are oftentimes ne- glected, causing serious delays to the shovel. On few jobs has the writer seen the shovels work to their capacity, on account of poor track arrangement and the consequent inability to keep the cars to the shovel. One must have good running track over the entire work. Shovel Work at Belle Fourehe Dam. The following was pub- lished in Engineering and Contracting, March 18, 1908, and in Engineering News, April 2, 1908. It refers to the cost of work on the embankment of a dam built under contract for the United 4S6 HANDBOOK OF EARTH EXCAVATION States Reclamation Service in South Dakota. This contract was suspended in January, 1908. The material of which the dam was constructed was a heavy adobe clay with occasional layers of shale. This material was excavated by steam shovels dumping into cars hauled by dinkeys, and also with elevating graders dumping into wagons. (For the cost of work done by the graders see Chap. IX.) The material was dumped, spread and rolled in 6-in. layers, all stones exceed- ing 6-in. in diameter being removed before rolling. The total volume of the dam is 1,600,000 cu. yd. and during 1906-07 about 32% of this amount was placed. During 1906 a 75-ton, 2^-cu. yd. dipper, steam shovel was em- ployed, and during 1907 two of these shovels were used. The material was hauled in trains of 10 Western, 4-cu. yd. dump cars by 18-ton Davenport dinkeys. The average haul during 1906 was 1 mile, up a 2% maximum grade, and during 1907, 1 mile do\vn a maximum 4% grade. Material was spiead in 6-in. layers by 4-horse buck scrapers and leveled by a 6-horse road leveler. The tracks were laid so that the earth was spread to a distance of 50 ft. from them, and then were shifted 10 ft. after the completion of every third layer. Sprinkling was done by means of a hose attached to iron pipes in turn connected to a pump. The rolling was performed by a 32-hp., 21-ton, traction engine, and a 12-ton road-roller. The traction engine was very efficient. Common labor was paid $2.25 to $2.50 and horses $1.15 per day of 10 hr. Coal cost $10.50 per ton delivered. The cost is given below, and the labor account includes the railroad fare of em- ployes, lighting, heating, superintendence, engineer, bookkeeper, timekeeper, blacksmith, machinist, clerk and building rental. These items amount to about 3.3 ct. per cu. yd. The charge for depreciation and repairs is based upon the estimated salvage of machinery and equipment. The supply account includes coal, oil, power, etc. The cost of sinking the artesian wells, each 1,430 ft. deep, and of obtaining suitable water for boiler use has been distributed in the itemized costs. . Cost of Steam Shovel Work on Belle Fourche Dam Embank- ment, for 1906 and 1907. (Yardage for both years was 305,000 cu. yd. The daily average per shovel was 951 cu. yd. per day of 10 hr.) ..iriiifii! r Excavation : Total Cost per cu. yd. Labor ' ; ; .v. .'.'I'.T. . .*?& .SAWUV. $14,215.01 $0.047 Depreciation and repairs ...., j*..\ % .. ,892.81 0.029 -- .......... -- ..... 8 ' 189 - 94 - Total .,..,. .,4,,w^mfW,*31,297.76 $0.103 COSTS WITH STEAM AND ELECTRIC SHOVELS 487 Hauling: Labor ............................ $11,228.17 $0.037 Depreciation and repairs ....... 9,285.76 0.030 Supplies .......................... 10,738.00 . 0.035 Total $31,251.93 $0.102 Jilflfu fc lOJ-JJilhtO') ^l! Main Track: Labor $ 3,633.29 Depreciation and repairs 3,991.96 Total $ 7,625.25 Rolling : Labor Depreciation and repairs Supplies $ 1,891.63 1,361.03 2,176.06 Total $ 5,428.72 > I TfJ . I M]M I Watering : Labor $ 4,143.20 Depreciation and repairs 3,611.69 Supplies 1,243.43 Total $ 8,998.32 Grand totals: Labor $ 71,163.44 Depreciation and repairs - 27,827.08 Supplies 22,347.43 Total . .. $121,337.95 $0.012 0.013 $0.025 $0.006 0.004 0.007 $0.017 $0.014 0.012 0.004 $0.030 $0.234 0.090 0.073 $0.397 Cost of Railway Work. Engineering and Contracting, Aug. 5, 1008, describes work that was done in the south on the excava- tion of a railroad. It comprises a month's work during the fall of the year, when the weather conditions were fairly good, there being only occasional rain storms. Description of Work. The work consisted of widening one side of a cut, the average height of the excavation being about 40 ft. The water in the side ditch of the cut was turned by boxes under the track into the ditch on the other side, making the work dry. The extra width given to the cut varied from 17 to 21 ft., and this distance would not allow of the regular jack arms being used on the shovel at all times. When this was not possible a special short jack arm was used on one side of the shovel, giving 2 ft. additional clearance. Short jack arms are valuable for such purposes, but the stability of the shovel is greatly reduced by their use. ^'S ' The railroad company operated its trains through the cut while the work was going on. In all there were about 30 trains a day on one track. Four of these trains were for passenger service and two were carded freights. These six trains had to be cleared by the contractor's dirt trains, ten minutes on their 488 HANDBOOK OF EARTH EXCAVATION running time, as furnished by the telegraph operator, kept in the contractor's camp by the railroad company. The rest of the trains were, cleared as they approached or else flagged until the dirt trains could take a side track. The contractor's* outfit was a standard gage, and the main line of the railroad was used as a loading track and for hauling the material. The excavated material was hauled two ways to the dumps. One haul averaged a mile and the trains were dumped from the main line, the material being used to widen a long embankment. The average haul to the other dump was 2 miles, and the material was dumped from a temporary trestle, being used to make a new embankment alongside of an old one. Half the material excavated went to each dump, as the time saved in dumping from the trestle compensated for the extra dis- tance hauled. The material excavated was a red clay mixed with mica and this clay could be classed as " average earth." In the two months 29,800 cu. yd. of this clay were excavated, and 1,200 cu. yd. of solid granite. The granite was in the bottom of the cut, over an area about 200 ft. long. Encountering this rock and having to take it out to grade retarded the progress of the shovel, as during the time the shovel was working in the rock the record of cars loaded each day was not over one-third as large as when working in earth above. The side of the cut was excavated to a %. to 1 slope, with the result that several cave-ins occurred. Two of these cave-ins moved the shovel a foot or more to one side and caused delays of 5 to 6 hr. while the shovel was being dug out by hand and the jack arms made solid. Outfit. The outfit was a new one, the shovel, cars and other tools for the most part having been bought new. The shovel was a Bucyrus 65-ton, with a 2^-cu. yd. dipper, with 14 x 14-in. crowding engines on the boom. The shovel used had only one piece of timber on it, a piece to protect the hoisting chain. The dipper was speeded to make 4 dips per min., and in good material it sometimes did it, loading 12 cars, 36 dipperfuls, in 9 min. The dipper had a lift of 17 ft. and could dig earth 27 ft. to one side, dumping 24 ft. on the other side, thus covering a distance of 51 ft. By placing the shovel on crib work, the shovel could dig 5 ft. below the base of rail. This style of shovel, equipped with extra short arm jacks, is well adapted to grade revision work on railroads, as it is not too heavy to move over wet ground, and has such a range of work as to admit of handling heavy excavation, with a minimum of track laying and shifting. Such a shovel also saves many moves forward in heavy excava- tion. When the pit is dry, this shovel could be moved forward COSTS WITH STEAM AND ELECTRIC SHOVELS 480 ft. in from 3 to 4 min., although it has been moved in 2 min. Jn wet, soft pits, when cribbing is necessary to hold up the shovel and jack arm blocks, from 5 to 10 min. are consumed in moving the shovel forward. The water tank on the shovel had a capacity of about 1,500 gallons. Two Rogers locomotives were used. These had 16-in. cylinders and four 51 -in. driving wheels. They were second-hand engines just from the shop, and each had had a new boiler put on it within 5 years. Their tanks carried about 3,000 gallons of water. Both of these engines did good service. Each train was made up of 12 Kilbourne and Jacobs, 6-yd., two way dump cars. A record of the cars loaded each day was kept, and this divided into the yardage given in the engineer's estimate showed each car carried 4} cu. yd. place measurement. Ordinarily 4 dippers of earth loaded a car, so each dipper load amounted to iy 8 cu. yd. place measurement. A gasoline pump pumped water direct to the steam shovel, and also pumped water into a 10,000 gal. wooden tank for the loco- motives. A 3%-in. Ingersoll drill was used in drilling the rock, steam being furnished from the boiler of the shovel. This drill was capable of putting down a 20-ft. hole. The cost of the outfit was as follows: Shovel (65 ton) $10,000 2 locomotives 10,000 24 (6-yd.) dump cars at $125 3.000 Tanks, pumps, etc., for water 1,000 Rock drill, etc 400 Blacksmith shop 200 Hydraulic jacks, etc 400 Small tools 1,000 Camp ' 1,000 Total $17,000 Accident. The shovel had been set up and was ready to dig dirt by Saturday night. In moving it into position over ground made soft by the previous month's rains, it careened to one side and fell over, the shovel and boom resting on the main track. 8 by 8 timbers 30 ft. long had been put under the ties to stiffen the track but a rail joint broke over a point where two of these timbers butted together. The wrecking crane sent by the railroad not being powerful enough to lift the shovel it was decided to place two " deadmen " or anchors in the ground on the side of the shovel away from the main line track and pull the shovel up in this manner. This was done, but owing to the soft ground the first " deadmen " pulled out. New ones were sunk much deeper and ties used to 400 HANDBOOK OP EARTH EXCAVATION brace them. A line was hitched around the boiler of the shovel and another to the " A " frame and heavy triple blocks used be- tween the shovel and the deadmen. Then two locomotives were hitched to each of the lines, and started off in opposite direc- tions. The shovel was thus pulled over onto its wheels, setting in the mud. About midnight rain began to fall and this retarded the work. By 5 o'clock in the morning the track was repaired and tratlic was resumed. On Monday began the work of repairing the shovel. The hy- draulic jacks raised the car high enough to build a track under it. Several gear wheels were broken on the boom and new ones were ordered by telegraph and put in place when they arrived. The dipper arm had been bent, and it had to be straightened. All of these things were done by the contractor's own forces in a week, and the shovel was again ready to go to work. The steel house was battered up somewhat, but a handy blacksmith fixed up all but the corrugated plates, and several of these were replaced a few months afterwards. Cost of Repairs. The cost of the repairs was about $1,100. Of this, $325 ^was for new parts for the shovel. The railroad com- pany's charges were $80 and the labor charges of men working on the shovel and waiting to go to work, such as train crews, amounted to $700. This included office men and all general ex- penses. This labor cost has been included in with the two months' work that is being described, as the contractor included it in with his regular pay roll and it was charged against the work done that month. The repair bill and the railroad com- pany's charge have not been included in with the costs to be given below. These were considered charges against the whole job. The total cost of the accident charged against the yardage moved at this point would amount to less than 1 ct. per cu. yd. Methods of Working. In order to operate the contractor's trains the railroad company furnished a telegraph operator, but the contractor boarded him free of charge. The dirt train operated on " work train orders." The railroad company kept an inspector on the work, and with the company's permission the contractor paid him a salary and put him in charge of the dumps as superintendent of dumps. This was found to be a very satis- factory arrangement. The temporary trestle was about 25 ft. high. It was built of round poles, costing 3 ct. per ft. delivered on the ground. The braces used were 3x8 in., and the stringers were 12 x 12, 18 ft. long, the bays of the trestle being 16 ft. long. This timber (pine) cost $10 per M ft. B. M. The trestle was erected by a sub-con- COSTS WITH STEAM AND ELECTRIC SHOVELS 491 tractor for $3 per M. This gave a cost for the temporary trestle complete of 1% .ct. for each cu. yd. dumped from the trestle. Only one-half the material excavated in these two months went to this trestle. Cost of Work. Below is given the total cost of the two months' work, inch-ding all cost to the contractor except the expenses in- curred at his home office. With a large number of jobs going on this item of expense would be small. A 10-hr, day was worked. The following prices were paid for supplies: Black powder, per keg $1.25 Dynamite, per Ib 0.11 Exploders (average) 0.06 Fuse, per 100 ft I 0.45 Caps, per 100 0.60 Coal (run of mines) , per ton 3.25 The total cost of the work for the two months was: Office and Superintendence: Engineer in charge 1 bookkeeper 1 clerk 1 telegraph operator's board 1 night watchman 1 cook and 1 flunky 1 superintendent Oil for camp Loading: 1 shovel runner 1 craneman 1 fireman 2 pitmen 4 pitmen $ 300.00 130.00 80.00 30.00 70.00 130.00 280.00 14.00 $1,034.00 $ 280.00 180.00 60.00 132.50 212.00 Blasting: Steam drill and drilling Powder and dynamite . Exploders, etc. f-rJilV 73 tons coal Oil, gear shield, etc Repairs to shovel ' Hauling: 2 locomotive enginemen 2 firemen 2 conductors 4 flagmen 1 car oiler 200 tons coal Engine and car repairs Oil, waste, etc !i; n nr?K<' it!. -i- $ 42.50 52.00 16.00 237.25 21.00 15.00 $1,248.25 $ 360.00 160.00 300.00 212.00 53.00 650.00 30.00 50.00 $1,823.00 492 HANDBOOK OF EARTH EXCAVATION Dumping: 1 inspector $ 80.00 1 fireman 132.50 12 men 636.00 1 fireman 159.00 20 men 1,060.00 Temporary trestle, 16,100 cu. yd. at 1% ct 281.75 $2,349.25 Miscellaneous : 1 blacksmith $ 169.00 1 blacksmith helper 53.00 Extra gang: 1 foreman, 1 month only 54.00 10 men, 1 month only 270.00 $ 546.00 Total labor and supplies $7,000.00 Interest and depreciation 1,080.00 Grand total $8,080.50 Interest and depreciation does not include repairs and is charged at the rate of 2% per month, worked. This is an ample allowance. The output of the shovel per day worked was nearly 700 cu. yd., but for the full number of working days in the two months the output per day averaged about 600 cu. yd. The average cost per cu. yd., including both earth and rock, for the details of the work, was: Office and superintendence $0.033 Loading 0.040 Hauling 0.059 Dumping 0.079 Miscellaneous 0.018 Interest and depreciation 0.035 Total per cu. yd $0.264 Where earth and rock are moved jointly it is not possible to keep the actual cost of each class of excavation, but the total cost of the two can be kept, and a comparative cost with the con- tract price for the earth and rock can be calculated. This is a cost that can be relied upon. To illustrate the comparative cost an example will be given. If earth is being excavated for 35 ct and rock for 75 ct. and 10,000 cu. yd. of earth and 5,000 cu. yd. of rock are excavated, and there is made a profit of 15% on the work, then the cost of the earth excavation will be 85% of 35 ct. or 29% ct., and the cost of the rock excavation will be 85% of 75 ct., or 63% ct. Such costs on this work figured out, there being a profit made of nearly 20%, gives for earth the following: COSTS WITH STEAM AND ELECTRIC SHOVELS 493 Office and superintendence $0.032 Loading 0.037 Hauling 0.054 Dumping 0.072 Miscellaneous 0.017 Interest and depreciation 0.033 Total per cu. yd $0.245 The cost of the rock excavation per cu. yd. was: Office and superintendence $0.085 Loading 0.098 Hauling 0.148 Dumping 0.190 Miscellaneous 0.046 Interest and depreciation 0.089 Total per cu. yd $0.656 Cost of Excavating Gravel in a Canal. Mr. J. B. Brophy furnishes the following data to Engineering and Contracting, Oct. 14, 1908. The work was done at the canal near Trenton, Ontario. The material was a gravel. The cutting was 1(% ft. deep and was side cutting, the material being loaded into cars as high as the machine would reach. From June 1 to 13 the shovel exca- vated 16,000 cu. yd., the average haul being 1,200 ft. From June 15 to 30, 20,000 cu. yd. were excavated, the average haul being 1,400 ft. This makes a total of 36,000 cu. yd. with an average haul of a little more than 1,300 ft. The outfit used on the work consisted of the following: A 65-ton steam shovel with a 2i-cu. yd. dipper, made by the Bucyrus Steam Shovel Co., of South Milwaukee, Wis. Two 12- ton Porter dinkeys. About l^-mile of track was used and 22 dump cars of 4 cu. yd. capacity. The cost of this outfit was approximately as follows: 65-ton shovel $ 9,000 2 (12-ton) dinkeys 5,000 22 (4-yd.) dump cars at $230 5,060 16 tons 20-lb. rails at $32 512 1,000 ties at 10 ct. 100 Total $19,672 Estimating 2% for monthly interest, depreciation and repairs, gives a charge per month of about $390. The shovel worked 12 hr. per day, but the track gang and water wagon only worked 10 hr. per day. We assume the standard wages on this class of work, which are: Shovel runner $125 per month >;a* Craneman 90 per month Fireman 60 per month Watchman 40 per month 494 HANDBOOK OF EARTH EXCAVATION Dinkey runners $3.00*per day Brakemen .... 2.00 per day Foremen. , 3.00 per day Oiler ' 1.75 per day Laborers 1.50 per day Water boy 1.00 per day Team (with driver) 5.00 per day During the month 26 days were worked. The total cost of the work and the organization of the forces were: W Loading: shovel runner $125.00 craneman 90.00 ! fireman 60.00 ' pitmen 156.00 team hauling water 180.00 50 tons coal at $5 250.00 Oil, waste, etc 10.00 Total loading $871.00 Hauling :- 2 Dinkey runners $156.00 2 brakemen < 104.00 1 oiler 45.50 1 trackman 39.00 60 tons coal at $5 300.00 Oil, waste, etc 16.00 Total hauling $660.50 Dumping: 1 foreman $ 78.00 16 laborers 624.00 1 water boy 26.00 Total dumping $728.00 Track gang 1 foreman . $ 78.00 5 laborers 195,00 1 superintendent 150.00 1 timekeeper 65.00 1 watchman 40.00 Interest, depreciation and repairs (estimated) ., 390.00 Grand total ; $3,177.50 The cost per cu. yd. of material excavated was: Superintendence $0.007 Loading 0.024 Hauling 0.018 Dumping 0.020 Track work 0.008 Interest, depreciation and repairs (estimated) 0.010 Total per cu. yd ..'.^.^1 $0^7 "ilinnnr vtij ".;_] . ...'^isfunn l'/od-f f ---r _ _ :i.!f';Vj:f ; b ui f 'M'fjfi- Labor Loading: Steam shovel pay roll $1,815.64 Section labor 99.94 Total labor $1,915.58 Work train service: Conductors, 95.8 days at $3.68 $ 352.54 Brakemen. 191.6 days at $J.53 484.75 Engineers, 95.8 days at $4.40 421.52 Firemen, 95.8 days at $2.95 '282.61 768 tons of coal at $4 3,072.00 1,916,000 gal. water (255,466 cu. ft. at .07 per 100 cu. ft.) '178.83 95.8 engine days for supplies at $0.32 81.0 engine days for depreciation at $2.03 164.43 81.0 engine days for repairs at $3 243.00 81.0 engine days for interest at $2.03 164.43 Total &394.T7 Coal Used by Steam Shovel: 172.8 tons coal at $4 $ 691.20 Total . $8,001.55 COSTS WITH STEAM AND ELECTRIC SHOVELS 499 Less Comp. Credits (Profits) Boarding comp ....................................... $ 174.27 Commissary ........................................... 15.74 Total credits [?$.&& .................... $ 190.01 Total cost, net ................................ $7,811.54 The cost was, therefore, 11.5 ct. per cu. yd. for 68,000 cu. yd. handled during the month. Excavation on the North Shore Channel, Chicago. Sections Nos. 4 and 5 of the North Shore Channel of the sanitary district of Chicago were contracted to James 0. Hayworth. The work of drag line machines on these sections was described in Engineer- ing and Contracting, April 27, 1910. The top 10 ft. consisted of a clay which could readily be dumped from dump cars, but below this the clay was heavy and tenacious and came in large lumps. It was excavated by a 70-ton Vulcan steam shovel with a 3-cu. yd. dipper. The steam shovel loaded into Western 3-cu. yd. dump cars which were handled by Daven- port locomotives out of the cut and onto the crib piers behind. which the spoil was dumped. These cars were dumped in the usual way until the sticky clay noted above was met, then they would not dump properly. A der- rick was then arranged to do the dumping. A sling was devised which would hook into and lift the car body from the trucks and by winding up on the engine would tilt the body and empty it. The cost of excavation, as kept by the engineers, was as fol- lows for 1908, when 194,280 cu. yd. were excavated: An 8-hr. day was worked and wages paid were as follows: Men in dump per day ................................... $1.50 Men around shovel per day ............................. 1.75 Steam shovel enginemen per month ............... $125 to $150 Steam shovel cranemen per month ....................... 90 The value of the excavating plant used was $16,035, and the assumed depreciation chargeable to Section 1 was $16,035 X 50% = $8,017. The total amount expended on excavation (194,280 cu. yd.) 'in 1908 was as follows: Materials: \ '' Total Operation ..................... . ..................... $8,639 Repairs and plant ................................. 7,156 Totals $15,795 Per cu. yd $0.081 Labor : Operation $32,241 Repairs and plant 3,295 Totals $35,536 500 HANDBOOK OF EARTH EXCAVATION Per cu. yd .......................................... $0.182 Grand totals .................................... $51,331 Per cu. yd .......................................... $0'.264 The items making up these totals were as follows: Materials : Operation Rep. & Pint. Shovel Dinkeys Track Dump Cars Coal Office Insurance General Totals $1,208 753 259 216 6,066 136 $8,638 Labor : Shovel ................. $8,728 Dinkeys ............... 5,876 Track .................. 5,951 Dump ................. 9,146 Cars Coal Office Insurance General 34 585 606 1,315 Totals $32,241 $1,502 1,148 2,222 1,863 360 61 $7,156 $ 820 359 1,975 8 103 $3,295 Total $2,710 1,901 2,222 259 2,079 6,006 360 197 $15,795 $ 9,548 6,265 5,951 9,146 2,009 585 8 606 1,418 $35,536 The costs of operation in excavation were distributed as fol- lows per cu. yd. : Steam Shovel: Labor $0.0450 Coal 0.0172 Supplies 0.0062 General 0.0034 Total $0.0718 Transportation : Labor Coal Supplies . . . General $0.0310 0.0171 0.0051 0.0009 Total $0.0541 Track : Labor General and supplies $0.0314 0.0009 Total $0.0323 Dump: Labor $0.0478 Supplies 0.0012 General 0.0023 Total $0.0513 Grand total COSTS WITH STEAM AND ELECTRIC SHOVELS 501 Steam Shovel: Labor $0.0021 Materials 0.0035 General 0.0004 Total $0.0063 Transportation : Labor $0.0061 Material , 0.0077 General . 0.0004 Total $0.0142 Track : Materials $0.0057 General '. . 0.0004 Total $0.0061 Grand total $0.0266 In figuring the net costs of repairs and plant charges the total estimated amount of excavation on the section, or 390,000 cu. yd. lias been used as the divisor. The reason for this is that the re- pair and plant charges itemized were all that were necessary to put the plant in shape to complete the work. Summarizing we have: Operation *. . $0.209 Repair and plant charges 0.027 Depreciation on plant 0.021 Total per cu. yd $0.257 Yearly Average Outputs on the Hill View Reservoir. The yearly output of steam shovels in building the earth embankment for the Hill View Reservoir, New York City, is given by Arthur Tidd, in Engineering Xews, Sept. 9, 1915. The formation was of very hard packed, dense, glacial drift, containing many stones and boulders but no ledge rock. The material was well graded from a coarse sand down to a very fine rock flour, and was a most excellent one for a reservoir embankment. All the material was excavated by steam shovels, and about 1(V/ ( sent out on trains. As long as the complete steam shovel plant could be operated (that is until the bank became so nar- row on top that the dumping area was restricted) the material was taken out of the basin by two tracks, one at the north and one at the south end, using pushing engines when the grade re- quired them. Both lines were relocated and regraded several times as the banks rose. The steam shovels used for the bulk of the excavation were four heavy 70-ton shovels, and four light 30-ton shovels. The large shovels worked in the heavy cuts, taking the full depth (40 ft. at the deepest point) at one time. 502 HANDBOOK OF EARTH EXCAVATION These cuts were, however, shot ahead of the shovel with black powder. The small shovels took the lighter cuts, and in a few cases ran through in two lifts. The material was handled in 4-yd. side-dumping cars in 10-car trains by 10- to 15-ton loco- motives running on 3-ft. gage track laid with 65- to 70-lb. rails. A large number of boulders of all sizes up to 1 yd., and in some cases 2 or 3 yd. in volume, were encountered everywhere throughout the cuts, and their handling became an important factor in the general excavation problem. Many boulders were saved for future use in paving, riprap or for crushed stone, but the accumulation interfered so much with succeeding excavation operations that the following seasons as many as possible were sent out onto the bank. A large force using a portable gasoline air-compressor for drilling was employed continuously breaking up boulders. Winter work helped somewhat, but the problem was an ever present and troublesome one. Although monthly outputs ranging from 20,000 to 24,000 cu. yd. per 70-ton shovel were not uncommon in the early part of the work, the best year output was 190,000 cu. yd., and the average yearly output for each of two shovels for five years was 120,000 cu. yd. The shovels^ere in use practically all the time. The length of working day was 8 hr., and one shift daily was worked. The average yearly output for each of three 30-ton shovels was 49,000 cu. yd., or about 40% as much as with the 70-ton shovels. A Good Steam Shovel Record. The Excavating Engineer, Oct., 1915, states that a 3-yd., 70-ton Bucyrus Steam Shovel, working in hard-packed sand with loam and gravel, at Providence, R. L, averaged 2,816 cu. yd. per 10-hr, day for 12.5 days, loading into 4-yd. cars. The face averaged about 12 ft. high. The ma- terial was hauled in three trains, of fourteen 4-yd. cars each, by 20-ton, 36-in. gage, locomotives, an average distance of about i/ 8 mile. During the 12.5 days about 0.5 day was lost the first day, and two other days were devoted to moving back to a new cut. Records on a Large Cut for Track Depression. Engineering and Contracting, June 28, 1916, gives the following: A 900,000-cu. yd. cut, which eliminates 39 crossings at grade was made in Minneapolis, Minn. In this work the tracks were lowered to give a clearance under bridges of 18% ft.; this neces- sitated a cut averaging 22 ft. in depth. The work was done by the operating department of the Chicago, Milwaukee & St. Paul R. R. with company forces. The total depth of the cut was made in from 5 to 7 cuts, COSTS WITH STEAM AND ELECTRIC SHOVELS 503 depending upon the depth carried. These cuts were generally carried for a stretch of about eight blocks at a time. The usual method of procedure was to use one track as a loading track while the shovel was making as deep a cut as possible to one side. This usually averaged about 8 ft. When this cut was completed to the required distance, a new track was laid here and used as a loading track while the shovel was shifted to the other side. The shovel used was a 65-ton Bucyrus equipped with a 2^-yd. dipper. This shovel was shipped from the manufacturer's shops in the spring of 1907 and has been in steady service for the past eight years. Three dirt trains were used, consisting of 25 ( 12-yd. ) Western air dump cars. Each train was hauled by a class C-2 (2-8-0) locomotive. Below is a statement, prepared by J. G. Wetherell, assistant engineer, who was in direct charge of the work, for the operating department, for shovel operation from April 19 to July 23. Total amount of excavation for season, cu. yd 195,908 Total number of days shovt'l worked 82 Number of cuts shovel made 8 Total distance shovel excavated (total length of cuts), ft 16,076 Average distance excavated per day shovel worked, ft 196 Average number of hours shovel worked per day, hr 8.80 Total number of cars loaded 17,107 Average number of cars loaded per day 208.6 Average number of cu. yd. per car, cu. yd 11.46 Average number of cu. yd. excavated per day 2,389.1 Average distance excavated material hauled, miles 5.28 Greatest excavation for 1 month (June), cu. yd 72,934 Average daily excavation for June, cu. yd 2,805 Delays amounted to 12% of the total time, distributed as follows: 3.4%, moving shovel from one cut to next; 5.3%, no cars, due to trouble at the dump or to main line being used for other purposes ; 1.3%, rain ; 0.2%, shovel breakdowns; 0.8%, derailments in cut; 1.0%, miscellaneous. Stripping in the Anthracite Coal Region. The following is from a paper by J. B. Warringer in the Am. Inst. M. E., as abstracted in Engineering and Contracting, Jan. 17, 1917. The work is stripping earth overlying coal in Pennsylvania. The equipment required for a one-shovel operation is about as follows : 1 70-ton shovel. 1 steam .drill. 3 18-ton locomotives. 1 water tank. 20 5-yd. dump cars. 1 boiler. 1 star drill. 1 blacksmith shop. Necessary rails, sills, pipe lines, tools, etc. The total capital outlay for such an outfit is approximately $30,000. The average force required to operate a one-shovel stripping consists of about 35 men, roughly as follows: 504 HANDBOOK OF EARTH EXCAVATION 1 foreman. 1 shovel engineman. 1 craneman. 1 fireman. 1 watchman. 2 laborers. 4 jackmen. 3 locomotive enginemen. 1 dump boss. 6 dumpmen. 1 track boss. 2 trackmen. 2 drillers, 8 helpers. 1 boiler fireman. 1 blacksmith and helper. 2 coal diggers. . 1 driver. 1 switchboy. The wages paid these men amount to $2,100 per month. The shovel engineman is paid $140 a month, the craneman $95; loco- motive engineman $0.25 per hr. These rates are all subject, how- ever, to the recent increases granted the mine workers, ranging from 7 to 15%. The method of opening a stripping with either a Bucyrus 70-ton shovel or a Marion 60-ton shovel, which are the two Fig. 51. Method of Opening a Stripping. types most widely used in anthracite stripping work, is as fol- lows (Fig. 51) : For the first cut the track is laid on the sur- face along one limit of the stripping, usually the 1 bottom rock side, and the shovel cuts down grade alongside the track until a depth of ft. is reached, this being the maximum cut that the shovel can take and load overhead. When the first cut is com- pleted for the length of the stripping, the track is laid in this cut and the shovel again cuts down grade until a depth of 9 ft. below the first cut is reached. The shovel then continues cut- ting toward the other limit, the additional depth being de- termined by the depth of surface over the vein up to 30 ft., which is considered the proper maximum height for a clay cut. COSTS WITH STEAM AND ELECTRIC SHOVELS 505 In working by the above method, it is necessary to leave a bench at least 13 ft v in width for the laying of the track. Local conditions, as a rule, render it impossible to maintain any such plan for the entire life of a stripping. The first cut as described above is always the first made in a stripping except in the case of what is known as a side-hill stripping. Here the track is laid on the surface and the shovel started at an elevation that will give the required cut at the vertical limit. Rock cuts are usually made from 22 to 25 ft. in height. The tracks to the dump are always on an ascending grade of 1%, but usually higher. Four per cent is common, and grades as high as 7% have been used. The grade of the tracks in the stripping pit is governed by the necessary rise in elevation to reach the dump. The locomotives used vary in size up to 20 tons, the latter being about the heaviest type that can be used safely on a dump of any height. A 20-ton locomotive will push: 10 4% cu. yd. cars on a 1% grade. 8 4% cu. yd. cars on a 3% grade. 6 4% cu. yd. cars on a 4% grade. The general and best practice for stripping tracks is to use GO-lb. rails and nothing under a No. 6 frog. Curves should be kept to under 10, but 20 to 25 curves are used, especially in forming a dump. Dumps are made of all heights and sizes. There is less main- tenance cost with heights of about 25 ft., as higher dumps tend to settle and slip in wet weather. The cars most widely used are side-dump cars having capacities of 4, 4X and 514 cu. yd. Some 8 and 10-cu. yd. cars have been used with success. Under proper conditions outputs as high as- 30,000 cu. yd. per month have been obtained for one shovel in clay. The aver- age is about 18,000 cu. yd. per month in clay, varying consider- ably according to season as shown in Fig. 52. Hoisting Planes. If the stripping is not too deep, all the ex- cavated material can be removed by locomotives. In many cases, however, this is not feasible, and hoisting planes must be re- sorted to. Practically without exception, even in the largest operations, these are single-track planes operated by small sec- ond-motion hoisting engines with a capacity of about 150 dump cars per day, or about the output from one shovel. The prac- tical problem involved in putting these planes down along the steep sides of the average pit is often a serious one. Some of the planes are anchored on a slope of 50 to 60 pitch by bars sunk into the solid rock to which the roadbed is tied, presenting a 506 HANDBOOK OF EARTH EXCAVATION very interesting sight. While nothing can be said against these small hoists for a one-shovel stripping, it is undoubtedly bad practice to use them in the larger operations employing two or more shovels. There are practically none of these that cannot be laid out so that the output from two shovels can be brought to the foot of one plane, and this plane should be equipped with a hoist capable of handling with ease 300 and more cars per day. This plane can be either single track or double track, but the grade should be maintained at about 20, which is the average for the single track planes now in use. 98.000 K.OOO f 80 000 \ . *"" ^ k ^ 78.000 / \ ^ \ 78.000 f \ / ^ \ / / TJ 70*000 \ f \ / 3 68*000 -- -"**"* y t / y 1 \ 9 f rzi \ s \ _ ... s ^ s V 50.000 48 000 * - o 1 E? 46.000 -* I V a \ t 1 1 i 1 3- a & s 42,000 2 < eo s g s 3 s Fig. 52. Stripping Operations of One Company Averaged by Months Over a Period of 4 Years. .Some figures have been worked up showing a comparison of cost of the two varieties of planes, taking a double track plane handling only the Output of two shovels which would allow the greatest advantage of comparison possible to the small hoist. The first cost of the small hoist job is very lo\\r, as the hoist itself is usually picked up second hand around the collieries. It would be something as follows for a 300-f t. length of plane : Hoist Tracks, track material, rope, etc. Grading for hoist and plane Total ... % 500 700 1,000 $2,200 For the double track plane with the larger hoist the figures would be: Tracks, track material, rope, etc $1,100 Hoist 5,000 Hoist house, pipe line, etc 800 Grading for hoist and plane 3 000 Total $9,900 COSTS WITH STEAM AND ELECTRIC SHOVELS 507 To operate the single-track plane two top-men, two bottom-men, one locomotive engineman, one hoist engineman, four men and a boss on the dump, are required, while the double-track plane would require three top-men, three bottom-men, two locomotive engine- men, one hoisting engineman and seven men and one boss on the bank. The comparative cost would be as follows: Single track Double track Labor per day $17.88 $26.21 Power 4.30 6.48 Interest and depreciation, 15% 1.00 4.00 $23.18 $36.69 Figuring 150 cars for the single-track plane, the operating cost per car would be $0.155 and at 300 cars for the double-track plane $0.122 or a difference of $0.033 per car. The location of the limits for a stripping are set on a line where the normal slope of the overburden figured from the bot- tom of the final cut intersects the surface. Naturally a shovel - cannot cut to any such slope and must accomplish the same re- sult by a series of steps. The normal slope that earth of a clayey nature will take is about 1 to 1. Sandy ground requires 1^ to 1 or even 2 to 1, while rock can be cut nearly vertically if the height of bank does not exceed one shovel cut. For greater depths, y 2 to 1 must be allowed or even 1 to 1 if the rock is of a shaley nature. The importance of having the foot of the strip- ping slope well back from the bottom rock of the coal, to prevent the washing of overburden into the exposed vein by rains, is very great. The standard width for this ledge or berm is 10 to 15 ft. Prices of Non-Revolving Traction Shovels. For low bank work in average earth, where the amount to be excavated is small, 20 to 35-ton shovels, usually fitted with traction wheels, but which can be arranged with railroad trucks, cost as follows, prior to the war: Shipping Dipper Clear height of lift Weight Capacity Traction wheels R. R. trucks Price 22 tons % cu. yd. 12' 2" - 13' 2" $4,750 32 tons 1% cu. yd. 12' 8" 13' 8" 5.600 Shovels of small size usually have vertical boilers. A 35-ton shovel, with a very high crane which increases the width of cut about 7 ft. and the height of lift about 6 ft., costs $5,800. These are regularly equipped with a 1^4-yd. dipper. Shoveling Soft Shale. On the P. C. & W. R/ R. in Ohio, a 35-ton Vulcan traction shovel was employed in loading blasted 508 HANDBOOK OF EARTH EXCAVATION shale into dump cars, at the time the author was on the work in 1903. The material was drilled with hand churn drills, holes being 15-ft. deep. Each hole was chambered with 1^ sticks of dyna- mite and exploded with 75 Ib. of black powder. About 4 holes per day were fired. The shovel had a 1^-yd. dipper. Six 3-yd. dump cars were loaded in 11 min. Only one train was used, the shovel waiting Fig. 53. Non-Revolving Traction Shovel with 2^4-cu. yd. Dipper. C min. while the train was hauled 800 ft. to the dump and re- turned by a dinkey. The dumping of the train, one car at a time, through the trestle occupied 3 min. The locomotive therefore travelled 1,600 ft. (going empty on an 8 or 10%' grade) in 3 min., or at the rate of about 6 miles per hr. Part of the waiting time is occupied by the shovel in moving, each 4 ft. move requiring about 3 min. The force employed was as follows: 1 foreman 1 shovel runner 1 craneman 1 fireman 1 locomotive runner 1 brakeman 1 pumpman 6 drillers 1 blacksmith 2 dumpmen The shovel consumed 28 bushels of coal and the locomotive 7 bushels per day. (Note A bushel of coal weighs approximately 75 Ib.) COSTS WITH STEAM AND ELECTRIC SHOVELS 509 About 500 cu. yd. were excavated in a 10-hr, day. On another section of this work a 65-ton shovel was operating at a disadvantage because only one train of 6 cars was provided. The train was loaded in 5 min., but 10 min. were lost while wait- ing for the return of the empty cars. A Steam Shovel Loading Wagons. The following is given by John S. Ely in Engineering News, July 14, 1904: A 45-ton Bucyrus steam shovel equipped with a 1%-yd. dipper, working in soft material, excavated a cut 8 ft. deep, and 22 ft. wide. Dump wagons were loaded with one dipperful each. The Fig. 54. Marion Model 250 Stripping Shovel. speed of the teams ranged from 160 to 180 ft. per min. The aver- age speed being 167 ft. the haul one way varied from 1,250 to 1,500 ft. and was partly up hill and partly down. The wagons were dumped without stopping. On one occasion when the haul was only 200 ft., 6 wagons kept the shovel busy. From 2:40 to 2:44^ p. M!, 4 wagons were loaded, then the shovel moved ahead 5 ft. in i min. and waited 2 min. for a wagon. From 2:48 to 3:02 P.M., 27 wagons were loaded and then the shovel moved ahead 5 ft. in 2 min. From 3:05 to 3:10 P.M., 12 wagons were loaded. Between 2:40 and 3:10 the first wagons made 2 round trips. In the above run about half the time was lost waiting for wagons, there being 26 wagons. The dipper loaded at the rate of 3 wagons per min., 510 HANDBOOK OF EARTH EXCAVATION but allowing 10 min. out of every hour for moving forward, an average of 2^ wagons per min. should have been maintained. This gives us this rule for obtaining the number of wagons re- quired for steam shovel work: To obtain the number of wagons multiply the haul in 100-ft. stations by 3. The cost of work was as follows: 1 steam shovel runner at $150 per month, or 60 ct. per hr.; 1 cranesman at $125 per month, or 50 ct. per hr. ; 1 fireman at $50 per month, or 20 ct. per hr.; 10 pitmen at 15 ct. each, or $1.50 per hr.: 1% tons of coal per day at $2.20 per ton, or 33 ct. per hr. ; incidentals at about 10 ct. per hr.; total, $13.23 per hr. of shovel time. Haul- ing cost $6.00 per day. On the day the record was kept the shovel out-put was 1,043 wagon loads, the best day's record was 1,078 wagons containing about 1% cu. yd. each. Mr. Ely believes the output should be 150 wagons or 180 cu. yd. (place measure) per hr. Large Kevolving Shovels. The largest steam shovels built are of the revolving type. Machines weighing 360 tons are in use, and are sufficiently successful to make it seem probable that the limit in size is not yet reached. These machines are chiefly em- ployed for stripping the over burden from ore and coal. Fig. 55 and the following table of specifications give an idea of the possibilities of this machine. TABLE OP SPECIFICATIONS OF MARION COAL STRIPPING STEAM SHOVELS 1% to 1 Slope of Spoil Bank MODEL 271 5- Yd. Dipper, 90-ft. Boom A C C" D E F 40' 57' 57' 22%' 4' , 18%' 42' 51%' 51%' 21%' 4' 17%' 44' 40' 40' 21%' 4' 17%' 46' 31' 31' 21%' 4' 17%' 48' 20' 20' 21%' 4' 17%' The dimensions for C, D, E, and F in the above tables are the limit for corresponding depth cover or over-burden " A," and all operations must be calculated to come safely within them. For depths of cover or over-burden less than that given in the tables, the dimensions for C, D, E, and F would remain the same as for the least depth " A," in each table. Thickness of coal vein has no effect on the stripping ability of these ma- chines unless conditions other than those above considered are encountered. A 360-ton steam shovel is used for stripping iron ore on the Mesabi Range in Minnesota. It is equipped with 6 to 8-cu. yd. dipper and has great reach. Fig. 56, taken from Engineering and Contracting, July 17, 1918, shows a cross-section of a single cut. COSTS WITH STEAM AND ELECTRIC SHOVELS 511 The loading track was laid in the surface of the ground as shown at A, and on this particular cross-section the great shovel had sufficient reach to push the accumulated spill from the cars clear of the further rail of the loading track. Fig. 55. Diagram Showing Eeach of Large Stripping Shovels. The divisions marked from 1 to 10 show the cuts that would have been necessary had the same cross-section been removed with a Model 91 shovel weighing 107 to 123 tons and having a 2^ to 4-yd. dipper, and the loading tracks for the different cuts are lettered from A to H. Track A is the loading track for the first k - -//'- J Fig. 56. Cross-Section of Cut Made by a Model 300 Shovel and Cuts Required to Remove Same Area with Model 91 Shovel. cut, track B for the second cut, track C for the third and fourth, and so on. Output of Large Stripping Shovel. Engineering and Contract- ing, Dec. 20, 1911, describes a large revolving shovel used for stripping 24 ft. of over burden from a bed of coal at Mission- field, 111. The shovel was made by the Marion Steam Shovel Co. and had the following general dimension's: Net shipping weight 135 tons. Approximate working weight 146 tons. Size of dipper, cu. yd 3 l / 2 Length of boom between centers 65 ft. Height of dump above rail (boom at 45 deg.)...45 ft. Radius of cut at 30-ft. elevation 74 ft. Radius of cut at bottom of pit 55 ft. Center of dump from pivotal center 66 ft. Radius at rear end of cab from pivotal center. 31 ft. 6 in. 512 HANDBOOK OF EARTH EXCAVATION Hoisting engine (double) 12 x 14 in. Swinging engine (double) 9x9 in. Crowding engine (double) 8x8 in. Boiler, locomotive type , 60 in. x 17 ft. Boiler designed for pressure of 150 Ib. Working pressure carried 125 Ib. The machine has been handling 1,600 cu. yd. per 8-hr, shift, and is being operated by men who have learned to operate it in this field. For several days the machine took out more than 2,000 yd. per day, and it is claimed by the builders that after the operators become expert the average output should equal this amount. As to expense, the machine is operated by 1 engineman, 1 crane- Fig. 57. Longitudinal Section of Revolving 150-Ton Marion Steam Shovel. man, 1 fireman, 1 oiler or roustabout, 2 track men and 1 water and coal man, making a total crew of 7 men. The machine is equipped with feed-water heating and purifying system, which reduces the coal consumption very materially and it is operated daily on about 2 tons of coal. Large Revolving Steam Shovel for Canal Construction. Ac- cording to Engineering and Contracting, July 1, 1914, the large size revolving steam shovel, frequently used in coal stripping work, may be profitably employed in certain kinds of earth ex- cavation. A machine of this type was used in connection with an inclined tipple in excavating Section 9 of Calumet Sag Canal, 111. An interesting feature of this plant is its ability to excavate the entire prism of the canal at one cut (except the solid rock at the COSTS WITH STEAM AND ELECTRIC SHOVELS 513 bottom) and place the material in the spoil bank at one oper- ation. The Calumet Sag Canal at this point had a bottom width of 36 ft., a depth of cut of 36 ft. and slopes of 2 horizontal to 1 ver- Fig. 58. Diagram Showing Arrangement of Revolving Steam Shovel and Steel Tipple for Canal Excavation. tical, thus giving a top width of 180 ft. There were about 6 or 8 ft. of solid limestone in the bottom of the cut, the remainder being a glacial drift consisting of sand, gravel, boulders and clay. Fig. 58 shows a typical cross-section of the canal prism and Fig. 59. Marion Model 36 Revolving Shovel. the general dimensions of the shovel and tipple. The steam shovel used was a Marion with a 3^-cu. yd. dipper and a 75-ft. boom. The extreme height of dump was 53 ft. above rails; ex- treme radius of dump 83 ft.; and the radius of cut at 34 ft. 514 HANDBOOK OF EARTH EXCAVATION above rails was 88 ft. The working weight of the shovel was 355,- 000 Ib. The tipple consisted of a cantilever incline of structural steel, which was carried by two parallel standard gage tracks on the canal berm with a hinged apron extending down the slope into the prism. On this incline were two standard gage tracks, which carried the two dump cars of 10-cu. yd. nominal capacity. These cars were operated independently of each other by a double cylinder double drum engine, with 10^- x 12-in. cylinders. A 100-hp. locomotive boiler furnished steam for the engine at 125 Ib. pressure. Fig. 60. American Railroad Ditcher Mounted on M. C. B. Trucks. The method of operation was as follows: The car was lowered into the- pit on the inclined apron and filled with two loads of the 3^-cn. yd. dipper, then hauled to the top of the incline where it ran onto a steel tipple frame, which was hinged to the top of the incline by a heavy shaft. The car was securely held on this frame by dogs which engage automatically. As the car reached its position on the tipple frame it released a latch which per- mitted the frame with the car to tip outward, thus dumping the load. A pendulum counterweight, attached to the tail of the tipple frame by a wire cable, prevented it from tipping too far, and returned it to its normal position after the load is dumped. The car was then lowered to the bottom of the incline by a foot brake. While one car was being dumped the second car was being loaded by the shovel; thus there were no delays waiting for cars. COSTS WITH STEAM AND ELECTRIC SHOVELS 515 The complete weight of the tipple with cars, engine, boiler, fuel and counterweights was approximately 300,000 lb., but as nearly all of this weight was carried by the rear truck, which is over 80 ft. from the edge of the slope, no trouble was experienced by caving of banks due to the weight of the machine. Railroad Ditchers or Locomotive Crane Shovels. These are lo- comotive cranes with a shovel boom hinged to the center of the I5UU _35 1400 1300 ^ 30 1200 1100 O 25 1000 i i * *~ 20 800 \> r 15 o 700 <3 15 I 600 3 *-* o- 500 ,0 ,00 300 1 l,vi 20 100 h'j-H Iiii>- 'n1 , 1 /?/ COTk'C C051 Cu. t tchl 7f//7C 50 'per rds.t fo2 ^Gajc cw.y Ci/.y jerc frd acit) Js.p d.= lay- eep. f of each Ditcher ~ zrhour \ Z:^ V S \ \; \\ \ s\ 1 s^ s \o ^ e^ *St \\ jjU '""' ^ ^ ^ s ^ or e ^l w ,^- " \ s ^N ^ ^ "re ^ --J": !-'" ^ X ^ ^ <^ ^ *** ^ L- ^ --" ;< - ls ^** l -*^, <: -^ **^ -*-*. r^ . -. - ^. * . ,<' ''<"" rr- ^-^ *. r-'' ^4567891 Fig. 61. Actual Working Hours. Cost of Handling Material with a Double Ditcher Train. mast. They are mounted on the flat cars they" load, or on special trucks. Single Track Revolving Shovels. These are built up to 40 tons in weight. They can load and dump at any angle which is of advantage in loading wagons but not at all necessary in loading cars on a parallel siding. For this reason most small revolving shovels are built with traction wheels. Cost of Handling Material with Double Ditcher Train. In Railway Maintenance Engineering the following daily cost of operating a double ditcher train is given: 516 HANDBOOK OF EARTH EXCAVATION Two operators at $125 per month $ 9.60 Two firemen 3.00 Interest on cars and ditchers 4.14 Depreciation on cars and ditchers 4.78 Oil, waste, etc 1.00 Coal 5.00 Locomotive coal, etc 15.00 Train crew 25.00 Repairs 2.00 Labor at $1.50 per day 6.00 $75.52 Fig. 62. Double Ditcher Train. Conditions. Train Four air dump cars, 80 cu. yd. capacity, two flat cars, one water car. Speed 20 miles per hr. Switch 2 miles to run. Based on the above figures and conditions the curves shown in Fig 61 are drawn. A Revolving Shovel for a Brickyard. Wm. J. Spear gives the following relative to the work of a Vulcan No. 1 revolving steam shovel. The machine weighed 28 tons and was equipped with a %-yd. dipper. The work was the excavation of clay for brick manufacturing. The shovel was required to dig only 80 cu. yd. per day. For this outfit only one man operates the machine and he fires, acts as engineer and trips the bucket door. The shovel loaded one %-yd. dump car. This car was pulled to the brick-yard, an average distance of 700 ft., by a horse driven by a boy. The shovel loaded a second car while the first was being hauled to the brick yard. The shovel worked 10 hr. and used 000 Ib. of coal per day. Water was furnished for the shovel from a tank that supplied the brick yard at a cost of about 7 ct. per day. One man was used to keep the track in condition and to clean up behind the shovel and around the cars. The total value of the outfit including cars was a little over $5,100 in 1908. Small Revolving Shovels. The following is from Dana's " Handbook of Construction Plant." Revolving steam shovels on traction or railroad wheels are as follows: Clear height of lift Size Shipping Dipper Traction R. R. 1914 No. Weight Capacity Wheels Wheels Price 15 tons % cu. yd. 8' 4" 9' $3,750 1 24 tons % cu. yd. 10' 6" 11' 3" 5.000 2 35 tons 1& cu. yd. 10' 6" 11' 6" 6,000 COSTS WITH STEAM AND ELECTRIC SHOVELS 517 518 HANDBOOK OF EARTH EXCAVATION A No. 1 shovel of the above type was designed for general use on such work as real estate development. For excavating small sewers about 3 ft. wide and 10 to 16 ft. deep a very narrow dipper of ^-cu. yd. capacity and a dipper handle about 30 ft. long are used. In digging deep trenches in very sandy soil where many shifts from place to place are necessary, and where frequent curves are encountered, this shovel is not a suc- Fig. 64. Horizontal Crowding Motion of Erie Shovel, Made by the Ball Engine Co., Erie, Pa. cess, but in firm earth where the sewer is long and continuous it is very efficient. 50 to 75 lin. ft. of trench 4 ft. wide and 12 ft. deep have been excavated and back-filled in 8 hr. by a machine of this type. One runner, one fireman, and two helpers form the crew. Platforms 16 ft. long of 12 x 12-in. timbers are necessary for the shovel to run on. These being built in four sections, each 4^ ft. wide, are carried forward by being hooked to the boom. For excavating cellars the shovel has a standard dipper handle COSTS WITH STEAM AND ELECTRIC SHOVELS 519 with a %-yd. bank dipper, and for unloading cars or erecting steel, a crane boom 25 ft. long designed for use with a %-cu. yd. clam shell or orange peel bucket, or a chain and hook. The price in 1914 was: Shovel with % cu. yd. dipper and 30-ft dipper handle $4,550 Standard dipper handle and % cu. yd. dipper 500 Crane boom without bucket 475 A revolving shovel with a horizontal crowding engine, which enables it to excavate very shallow cuts economically, has inde- pendent engines for hoisting, swinging and crowding, and a ver- tical boiler. Rated Shipping wt. Dipper capacity Size Wt. equipped capacity 1914 per hr. No. (Tons) (Tons) Mounting (cu. yd.) price (cu. yd.) 13 15 Standard % $3,750 3540 1 26 30 Gauge or 1 5,500 5060 Special 20 20 Traction % 4,750 4050 A Mired Revolving Traction Shovel Can Lift Itself several inches off the ground so that planking can be placed under the wheels. This is done by dropping the dipper to the ground as illustrated in Engineering News, Dec. 28, 1916 and starting the crowding or boom engines, and forcing the dipper handle in an upward direction. As the dipper is placed flat on the ground it is impossible to force it below the surface. Consequently, when the boom or crowding engines are started, the shovel is forced to rise off the ground. Cost of Excavating a Cellar with a Revolving Shovel. Ac- cording to Engineering and Contracting, Apr. 15, 1908, in digging the foundation and cellar of a new building, in Minneapolis, Minn., the contractor used a steam shovel manufactured by the Brown- ing Engineering Co. This shovel was a locomotive crane with a dipper and dipper arm attached to the boom. One advantage of this shovel is that the boom angle is variable, being raised and lowered by a lever convenient to the engineer's hand. The dipper arm works on a shipper-shaft through the boom. This allows the dipper to dig both low down under the boom, and also high up on a bank. In digging this cellar, the shovel at first dumped the dirt di- rectly into the wagon, but afterwards into a hopper, under which the wagons were driven and loaded. This hopper was roughly made, having no bottom, but it saved the wagon from being hit by the dipper, and also prevented dirt from being spilled off the wagon when loading. The hopper was picked up and moved about as needed by the crane. 520 HANDBOOK OF EARTH EXCAVATION Two men only were needed to operate this shovel, the engineer and fireman; the latter both fires and trips the dipper door. The cost of operating the shovel per day was as follows: Engineman, 10 hr $3.00 Fireman, 10 hr 200 Coal, % ton at $4 2.00 Oil and waste , 0.30 Total operating cost per day $7.30 The material in this cellar was hard stiff yellow clay, part of the time frozen from 6 to 10 in. The shovel averaged 400 cu. yd. per day. A further reason for this small output was a lack of wagons. Nevertheless the cost of loading the wagons was only 3 ct. per cu. yd. and. including taking the shovel to another job 3 miles away the cost was only 5 ct. per cu. yd. The Empire Engineering Co., of Montreal, Canada, moved one of these shovels over an ordinary wagon road a distance of two miles, under its own steam. Two sets of rails were used, the machine picking up the set in the rear and swinging them around in the front. The cost of moving was: One engineman, 3 days $9.00 3 laborers, 3 days at $1.60 14.40 Fuel 4.00 Oil and waste 60 Team hauling water, 3 days 10.50 Total $38.50 This makes a cost of $19.25 per mile, which is very cheap. The fact that the crane revolves cheapens the moving as well as much other work it does. In moving ahead in the cut the track is moved in the same manner. Then, too, when the machine has cut to the end of a row, it does not have to be turned like a shovel, but it revolves on its circle, and immediately begins digging. In cellar excavating, after the earth is excavated, the dipper arm can be taken off, and the machine used as a crane for hoist- ing and erecting, or for pile driving, and for other purposes. It can be equipped with a clam-shell bucket, and used for un- loading sand and stone from cars, and also for unloading coal. Steam Shovel Work at Springfield, Mass Mr. Charles R. Gow, in a paper published in the 'Journal of the Association of En- gineering Societies for December, 1910, gives some facts and fig- ures concerning the operation of a No. 1 (24-ton) shovel of the revolving traction type. This shovel was assembled at the rail- road siding and transported about 6} miles over extremely bad roads. Plank track was necessary and the time occupied COSTS WITH STEAM AND ELECTRIC SHOV f ELS 521 was six days. The cost of unloading, assembling and trans- porting to work was $25,3.15. The depth of excavation varied from 1 to 17 ft. Part of the ground was fairly easy and the shovel excavated 300 to 500 cu. yd. per day, or at the rate of one loaded team per min. while actually working. The re- mainder of the excavation was in extremely hard ground with many large boulders and a shovel of 60 to 70 tons would have been more economical. The yardage fell to 100 cu. yd. per day. In the light cut of 1 to 2 ft. the dipper was crowded 7 ft. horizontally, thus tilling it reasonably full. The cost of steam shovel excavation at Springfield, Mass., 45,- 081 cu. yd. during 191 working days, or 235 cu. yd. per day, was: Cost of delivering and installing shovel $ 495.89 Foreman, supervising 1,668.00 Shovel operation, labor 2,118.81 Shovel operation, coal, oil, etc 1,487.67 Total cost of operation $ 3,606.48 Per cu. yd 0.080 Repairs, labor $ 315.57 Repairs, materials 631.14 Total cost of repairs $ 946.71 Per cu. yd 0.021 Depreciation on shovel $1,758.16 Teaming excavated material 9,692.42 General expense, 12.9% 2,344.21 Grand total $20,511.86 Total cost per cu. yd $0.455 The cost of repairs is exceptionally high on account of the very difficult nature of the work performed. Two new booms were supplied by the makers to take the place of broken ones, the second being of a special design. Several new dipper arms were required and the dipper teeth, chains and ropes were replaced every few weeks. A No. 1 shovel, working in a cellar excavation about 13 ft. deep, loaded the material, which consisted of pliable clay with a few 12-in. boulders, into cars drawn by a horse along a single track. The costs were as follows: Wages of engineman ".I $4.00 Wages of fireman ! 2.00 Wages of one foreman 3.00 Wages of three laborers 5.25 Coal 4.00 Oil, waste, etc 1.00 Interest, depreciation and repairs (estimated) 5.30 Total $24.55 Cubic yards per day , . 410 Cost per cu. yd 6 ct. 522 HANDBOOK OF EARTH EXCAVATION The Thew Revolving Shovel is made in the following sizes: A-l 1 2 3 4 Weight tons 15 18 24 32 35 40 55 Dipper capacity, en. yd. 7 /8 lVs-1% %*-!* !%-!%* Capacity cu. yd. per hr. 40 40 60 80 50* 100 Coal, daily, Ib. One man Two man operation 600 1,000 1,500 operation 1,000 1,000 1,500 2,000 * lu shale or hardpan. COSTS WITH STEAM AND ELECTRIC SHOVELS 523 The shovel is furnished with two forms of boom equipment: the horizontal crowding motion which possesses definite ad- vantages for shallow cut work; and the shipper shaft crowding mechanism and long dipper stick for use where maximum operat- ing ranges are desired. "' --* //I " Fig. 66. Horizontal Crowding Motion of Thew Shovel. Excavating a Street with a Revolving Shovel. According to Engineering and Contracting, June 9, 1909, a No. O (15-ton) Thew steam shovel was used for excavating about 18,000 cu. yd. for the repaving of Wentworth Ave. in Chicago. The cut ranged from 14 to 16 in. in depth. The shovel loaded directly into wagons and had to wait on the wagons. This limited its output which, however, ran from 150 to 300 cu. yd. per 8-hr. day. The shovel was operated by a shovel- man and a fireman. A snatch team was used 'at times to help wagons out of the pit. Altogether the working gang employed at the shovel was 8 men. About 1 ton of coal was burned per day. The success of the shovel on this work was due to its full circle revolution and horizontal crowding motion. Operating a Revolving Shovel in Brick Clay. Engineering and Contracting, April 12, 1911, gives the following: The Macon Brick Co., of Macon, Ga., used a 25-ton Vulcan re- 524 HANDBOOK OF EARTH EXCAVATION volving shovel for excavating about 100 cu. yd. of brick clay per day. The shovel is equipped with a %-yd. dipper. The dipper han- dle is 12 ft. long and will dump 12^ ft. above the rail. It will clear a floor 32 ft. wide and make a cut 40 ft. wide in a 6-ft. bank. It swings through a full circle. The Macon Brick Co. employed the following men in their work: 1 engineer, per day $3.00 1 helper, per day 1.25 2 trackmen, per day 2.50 Oil, waste and repairs, per day 50 Coal, 600 Ib. per day 1.05 Total labor and fuel , $8.30 The shovel is in operation only a part of the time and could furnish twice as much clay from the 8-ft. bank if the clay were needed. Excavating a Building Foundation with a Revolving Shovel. Engineering and Contracting, July 30, 1913, gives the following: In excavating for the foundations of a reinforced concrete building in Boston, the Aberthaw Construction Co. of Boston ob- tained cost figures which are low for a city job where the hauls to dumps averaged over a mile. The site was excavated to 10 ft. deep; the digging was good; there were no rocks, the material being mostly cinders. A %-cu. yd. Thew steam shovel was used and the carting was done by 2-horse end dumping wagons each of a capacity of 2 cu. yd.; in other words, each wagon had a ca- pacity of three shovelsful. The total cost of the 6,076 cu. yd. ex- cavated, including excavating, labor, teaming and dumping, lum- ber for runs, and all fuel and other expense in connection with the shovel, was 66.8 ct. per cu. yd. The itemized figures are presented below : Excavating: Shovel, 25 days $ 300 1 fireman, 25 days at $18 per week ) 99Q 1 engineer, 25 days at $37 per week i zzy 1 foreman, 25 days 6 hr. at $5 83 2 laborers trimming around shovel at $2 100 Preparatory to shovel and other labor, during shovel- ing, 411 men at $2 ; estimated 10% at dump 740 Miscellaneous laborers 37 $1,489 Excavating 6,976 yards, 21.3 ct. per cu. yd; does not in- clude runway. Hauling and Dumping: 481 teams at $6 $2,886 Foreman, 32 days at 10 hr. at $5 176 Laborers Lumber for runs 31 $3,175 COSTS WITH STEAM AND ELECTRIC SHOVELS 525 Teaming and dumping 6,976 yd. cost 45* ct. per cu. yd. Total cost per yd. of excavating, teaming and dumping was 66.8 ct. Revolving Shovel Working Excavating Macadam. James L. Kehoe, describing a pavement job in Newburgh, N. Y., in Engi- neering and Contracting, July 8, 1914, says: Old macadam was encountered on the section of street having no car tracks, on the remainder, gravel and hardpan. Owing to the short time allowed to complete the work, together with the hard cutting it was deemed advisable to use a steam shovel. On the old macadam section a No. (15-ton) Thew steam shovel of the traction type was placed in the center of the street loading from both sides into 1% and 2-cu. yd. dump wagons. Cuts averaged from 12 to 18 in. deep at the center line, and 4 to 6 in. at the curb. A level cut to grade was made by the shovel across the. street for a width of 25 ft. The material near the curb was piled in front of shovel by means of buck scrapers working evenings, or before starting in the morning. In this way the shovel always had enough material to load all teams for the first trip without loss of time. Owing to the shallow cutting the shovel was moved up about every 5 ft. and when there were no teams to load the shovel kept crowding ahead piling material. The average loading time for a li^-cu; yd. wagon was 1 min. Fifteen teams averaged 250 cu. yd. per day of material hauled from the shovel. On the hardpan and gravel section the shovel was placed between the trolley tracks and curb, loading across the tracks into side dumping trolley cars and dump wagons. On account of the boom on the shovel having only a few inches clearance from the trolley feed wire, two extra men were employed to raise and lower the wire, using notched poles. As the traction company maintained a 25 min. schedule some time was lost by the shovel on account of the wire being raised and lowered so often. Earth between the tracks was plowed with a heavy rooter plow hauled by a trolley car, the shoe on the plow being set so that the point just cleared the ties. This loosened material was shoveled to one side by hand and left for the shovel to load. On this sec- tion some hard shale was found about 6 in. below grade, but the shovel had no trouble cutting through it. Many predictions of failure were heard from the " sidewalk inspectors," but after the shovel had scooped several dippers of macadam they were convinced that it would excavate the entire street. Water for the shovel was piped in the same manner as for the mixer, a %-in. T being placed every 50 ft. A fine grading (or trimming) gang of ten men followed closely 526 HANDBOOK OF EARTH EXCAyATION behind the shovel grading to stakes set from a grade line stretched from curb to curb. About 600 sq. yd. of fine grading was the average per day. Street Grading with a Revolving Shovel in Los Angeles. The Excavating Engineer, June, 1914, describes a grading job on which, despite the shallow cutting, a small revolving shovel was used to splendid advantage. The total yardage amounted to 23,016 cu. yd., bank measure, which was handled between March 10th and April 25th, 39% days in all, including Sundays. The shovel, which was an 18-B Bucyrus, equipped with a %-yd dipper, burned fuel oil. 12 tanks, or 10,080 gallons were con surned during this period. The oil cost $12 a tank. Throughout the entire job, Sundays were regularly devoted to washing out the boiler, cleaning the flues and making sundry repairs, which, doubtless accounts to a large degree for the reg- ularity of the output. Although the greater part of the material was classified as earth, there was over 7,000 yd. of rock and sand- stone, besides 2,300 yd. of hard adobe clay, which, naturally cut down the capacity of the shovel considerably. The following data are given for the performance of this shovel : Total yardage (bank measure) 23,016 cu. yd. Total time under steam 34% days. Lost time including delays for moving, blasting, re- 23% hr. pairs, etc ; 67.8 cu. yd. Average yardage per hr. working 63.4 cu. yd. Average yardage per hr. under steam including delays. ) 735 wagons Maximum output per 11-hr, day bank measure \ 1,000 cu. yd. Cost of labor and fuel 3.3 ct. per cu. yd. The best week's output was perhaps the first week in April, the record of which shows that 4,649 wagons were loaded with 6,300 cu. yd. of material in 75 working hr., giving an average of 84 cu. yd. per hr. including delays. It might be interesting to note that after the completion of this job, the shovel was moved a distance of about 7 miles in 2% hr. by the use of two five-ton automobile trucks. The pro- pelling was done entirely by the trucks al a cost of $2.25 per hr. per truck. Basement Excavation with Revolving Shovel. Professor A. B. McDaniel, in Engineering Record, June 16, 1915, describes methods employed and gives detailed costs of excavation for two build- ings. The following is an abstract of his article: Case 1 Steam-Shovel Excavation. A steam shovel was used in excavating for the iirst building, which is being constructed for the Dennison Manufacturing Company, of South Farmingham, Mass, The building is rectangular in form, 70 ft. x 159 ft. 5 in., COSTS WITH STEAM AND ELECTRIC SHOVELS 527 with two projecting stair towers and a toilet tower. The general plan of the building is shown in Fig. 67. The soil excavated was a fine, clean, siliceous sand, in beds from 3 to 7 ft. in depth, and separated by strata of yellow clay, of a depth of 1 or 2 ft. The excavation was carried down to a gravel subsoil, upon which the footings were placed. The depth of excavation varied from 8.2 to 10.5 ft. Fig. 67. Path of Steam Shovel. The excavated material was used to fill up two low, swampy tracts of land which were located about i mile from the site of the building. Method of Excavation. A new Thew Automatic revolving steam shovel, type O (18-ton), equipped with a %-yd. dipper, was used for the bulk of the excavation. The manufacturers furnished an expert engineer who set up and operated the ma- chine for several days, during which time he broke in a "green 528 HANDBOOK OF EARTH EXCAVATION hand " as the runner. The latter operated the shovel without aid or supervision during the last ten days of the work. The shovel began operations near the southwest corner of the building plot, and excavated a cut abo t 15 ft. wide on a de- scending grade of about 10%. As the shovel approached the northeast corner of the plot it reached the finished grade, which was about 10.5 ft. below the original ground surface at this point. Path of Shovel. The path of the shovel is shown by the dash line in Fig. 67. The east side of the excavation was complete! first, as it was desirable to construct the footings and erect the basement column forms along this side, adjacent to the mixer plant and pouring tower, as early as possible. While the shovel was excavating in a southerly direction along the east side, a slip scraper was used to cut an inclined road from the north gate on Grant Street, along the north side of the plot, and curving and descending on a grade of about 6% to the bottom of the exca- vation near the north end of the toilet tower. After the shovel had started on its second trip along the plot the wagons came in at the south gate on Grant Street, passed down the incline along the south side of the plot, around the east side of the shovel, where they loaded and passed up the north incline and out the north gate on Grant Street, to the dump. Support for Shovel. On account of the loose character of the soil and the inflow of water when the excavation reached grade, it was necessary to support the shovel on planking. A .movable, sectional, platform was built of 4 x 8-in. timbers, bolted together to form sections 3 ft. wide and 12 ft. long. Four of these sec- tions were used on straight stretches, and two triangular-shaped sections, half the size of the rectangular sections, were employed on the turns. Near the center of both ends of each section was placed a heavy iron eye by means of which the section could be shifted around with a chain attached to the dipper arm. Neglecting time lost through breaks in machinery, inclement weather, etc., the shovel was excavating about 60% of the work- ing time. Special effort was made to keep the shf>vel always supplied with w r agons to load, and very little delay was occasioned from waiting for teams. From two to three shovelfuls were re- quired to load each wagon to an average capacity of about 1} cu. yd. (loose measurement). On account of the looseness of the material, the average shovelful was about } cu. yd. Based on a large number of observations, the average time to make a com- plete dipper swing was 26 sec. and the minimum time was 18 sec. The average time to load a wagon, with three swings, was 1 min. 46 sec., and the minimum time was 1 min. 21 sec. COSTS WITH STEAM AXD ELECTRIC SHOVELS 529 Labor and Fuel Costs. The labor crew consisted of one fore- man, one engineman, one fireman and two pitmen, or laborers. Following is a schedule of labor expenses per day of 9 hr. : 1 foreman at $6 per day $ 6.00 1 engineman at $0.45 per hr 4.05 1 fireman at $0.30 per hr 2.70 2 pitmen at $2.03 per day 4.06 Total labor cost per 9-hr, day $16.81 Water was supplied to the boilers through a rubber hose. Coal and coke were hauled thrice daily from a pile on the east side of the excavation and shoveled into a large wooden bunker built on the rear of the machine. The fuel cost for the operation of the shovel for 17 days was as follows: 7 tons coal at $6.25 $43.75 1 ton coke at $6.75 6.75 Total cost of fuel $50.50 The excavation was leveled up and made closely to grade by the use of a slip scraper, which was attached by a chain to the clipper handle. This work was done as far as practicable, during the short periods of waiting for wagons, at the beginning and end of each half day's work. The hauling away of the excavated material was done by rear dump carts hauled by two horses. These carts had a rated capacity of 1 cu. yd., and were generally filled by three dipper- fuls to a capacity of 1} cu. yd. Care was taken to place the bulk of the load over the rear axle, so as to facilitate the dump- ing. From 8 to 14 teams were used and the latter number proved to give the most efficient operation of the shovel. The average haul was 1,800 ft. The teams were run continuously in a circuit, and except for a short distance (about 200 ft.) the loaded teams were not allowed to pass the unloaded teams. Bunching of the teams was largely eliminated by careful supervi- sion of the dumping and the movement of the carts along the road. A decided tendency to lag was noticed each day during the last hour of work. Some drivers would stop work during the last half hour if they thought that another load would take until after 5 o'clock to dump. In the morning several teams were usu- ally late in arriving at the shovel for the first load. In order to eliminate these time losses, at the end of the first week's work a bonus of 25 ct. was offered to each driver who made 24 trips per day. During the first day's work under the bonus plan one man made 25 trips, four men made 24 trips and seven others raised their previous day's record by one trip. After a study of 530 HANDBOOK OF EARTH EXCAVATION this result a bonus schedule was established as follows: 25 ct. per day per man for 24 trips ; 40 ct. per day per man for 25 trips; 50 ct. per day per man for 26 trips. The average mimber of trips per day per team for the last full day's work (July 22) was nearly 25. Several teams made 26 trips per day. Time Records. A timekeeper stationed near the building site kept a record of the time that each team entered the south gate and left the north gate. This record served to show the character and length of delays in the yard, such as loss of time in pulling up to shovel, and delay at the shovel. The dump foreman kept ELECTlRIC SHOVEL& 530 mission of Utah is employing steam shovels on heavy cuts and sidehill work in connection with road construction projects. On one job in Weber Canyon, near Henefer, a 20-ton Bucyrus Model 18-B, working on sidehill cuts for roadway, moved about 400 cU. yd. per 8-hr, shift for several days. The material was about 35% earth and 05% boulders, ranging from 6 in. to 3 ft. in diameter or even larger. Some of the larger boulders were broken with blasting powder ahead of the shovel. The total oper- ating expenses per 8-hr, shift were as follows: wia-z ^m?> jiora Vrt'eilhta '*&% <>"* ^uitfiov/ ,n,l> * Team and wagon ................. . ..................... $ 6.00 Steam shovel engineman ................................ 6.00 3 men at $4 .............................................. 12.00 Field engineer ........................................... 6.00 Coal ..................................................... 4.00 Oil ..................... ................................ LOO Total per day l.'^!^!.^. ^.J^.^L^l... $^00 Taking into account the time lost for occasional repairs, a unit price of 10 ct. per cu. yd. was obtained on the greater part of this work. Steam shovel work in Willow Creek on the Castle Gate-Du- chesne post road, Carbon County, Utah, had the following quan- tities in the July estimate, 1918: Wyfil - I'tiii yl.'fy/ . l r'liiitt t ittn'i & f i,'>x*t ."'ftrt 1 * Cu. yd. E arth ..................................................... 3,500 Loose rock ............ ............... ..................... 1,000 Solid rock ............... ...... ........................... 1,800 Total .... ;;':CV;i . ivl AwL Ji' f :wyJLfl 6,300 The pay roll covering this work, including blasting the ledge rock and large boulders and some leveling and finishing of the grade, amounted to $1,283, giving a unit cost of 20 ct. per cu. yd. Motor Trucks Loaded by Steam Shovel. When motor trucks are used in earth excavation, the spoil is generally loaded onto a platform or into a hopper, and thence dumped into trucks, in order that the trucks may be kept off the soft ground. In the excavation for the cellar of the Circle Building, at Columbus Cir- cle, New York City, according to Engineering News, September 30, 1915, the trucks were sent directly into the cellar being exca- vated. Three-ton motor trucks were loaded by a steam shovel, which started at one end of the site and worked lo the other end, where it turned around and dug its way out. Each truck held 4 cu. yd. of earth. Twenty trucks were employed, each hauling seven loads per day. The trucks were drawn out of the excava- tion by a cable operated by a hoisting engine. Motor Trucks for the Public Service Terminal, Newark, N. J. Engineering and Contracting, July 12, 1916, gives the following: 540 HANDBOOK OF EARTH EXCAVATION The contract by Holbrook, Cabot & Rollins, New York, N. Y., for the Public Service Terminal at Park Place, Newark, N. J., called for the excavation of over 120,000 cu. yd. of earth to be removed from a plot 900 ft. long, with an average width of 140 ft. and a depth of 25 ft. below curb. In addition there were 136 caissons, averaging 8 ft. in diameter, to be sunk to a depth of at least 58 ft. in order to reach rock. In hauling the excavated material from ten to twelve Fierce- Arrow trucks were employed. The trucks were operated 18 hr. a day, working two 9-hr, shifts of men, one going on at 5 A. M. and the other quitting at midnight. With ten trucks in service the average working per day was 9% trucks. The only truck troubles were a few broken springs, due to the rough road over which the hauling was done. With the ten trucks working 18 hr. per day, 28 trips per truck, of 5^ miles, were made. Each truck carried a load of 4 cu. yd. or a total of 112 cu. yd. per day. The trucks were loaded by steam shovel, and the average time of loading was 3 minutes. A concise statement of the operations is contained in the following report, submitted Dec. 2, 1914, after the work was well under way: Ten 4-yd., 5-ton Fierce-Arrow trucks in 15 weeks carried 53,000 cu. yd. earth excavation 7 miles to make a four-foot fill 18 ft. wide and 2 miles long. This sand, loam and gravel was loaded by a Bucyrus 18-B, 25-ton revolving shovel from the %-yd. dipper directly into the trucks, which took it up a 400-foot 5% grade planked ramp, then over cobblestone and other poor pavement in streets with car tracks and over one drawbridge to the above mentioned fill, which was parallel to, but only connected at intervals with, the turnpike road. The time of loading varied from one to five min- utes and up. Unloading, aVout the same time. The following are the figures : Number of trucks on the job 10 Number of trucks actually at work, average about. . 9% Number of loads 13,928 Average loads, cu. yd 3 - Average weight of load at 98 Ib. per cu. ft. tons 4.9 Total mileage for 9V 2 trucks 98,888 Average mileage 1 truck 10,400 Number of days worked (Sunday not included) Number of da'ys two shifts worked Total shifts worked in 90 days Average miles per 9% hr. shift for 9% trucks 600 Average mile per truck per 9% hr. shift The books show that the overhead expense was $8 a day, which included interest, insurance, garage service, and the salaries of the two drivers. The operating expense was shown to be 18 ct. per mile, which included tires, gasoline, oil, repairs and depre- ciation. Figuring on the basis of each truck making 154 miles per 18-hr, day, which was the average, the total cost per truck per day was $35.72, and this reduced to the cost of yardage removed, figured out 32 ct. per yd. COSTS WITH STEAM AND ELECTRIC SHOVELS 541 In estimating what the cost of doing this work with horse teams -vould have been, it was figured that there was a saving of approximately 60% in favor of the motor trucks. The net saving on this basis would amount to $550 a day. It is some- what idle, however, to speculate along these lines, for it is a plain statement of fact that horse teams simply could not have done the work at any cost within the contract time. Electrically Operated Shovels. Engineering and Contracting, Dec. 14, 1910, gives the following: The mechanical equipment of an electrically operated shovel, i. e., the dipper, boom, car and trucks, is built along the familiar lines of the steam shovel. The power equipment consists of a motor of from 50 to 200 hp. to operate the hoist, and two motors of from 25 to 80 hp. to swing the boom and operate the thrust. The hoist and swing motors are located in the car, and are geared to the drums through suit- able reducing gears. The thrust motor is mounted directly on the boom, and communicates its motion to the bucket staff through reducing gears connected to a pinion engaging a rack on the staff. The motors are of the crane or mill type, with high torque char- acteristic, and may be for either direct or alternating current. They are reversing and are under perfect control. When desired the controllers may be connected to the ordinary hand lever used on steam shovels, so that a steam shovel engineer can operate the electric shovel without any trouble. Data in regard to the sizes, capacities and motors required are given in Table I. TABLE I ELECTRIC POWER SHOVELS Weight Size of shovels of dipper Hp. of motors Tons Cu. yd. Hoist Thrust Swing 30 1 50 30 30 35 1& 50 30 30 35 1*4 60 30 30 35 1^4 75 35 35 42 1V 2 75 30 30 65 2 100 35 35 95 3% 150 50 50 100 4 200 80 80 The power is ordinarily taken from trolley wires, or from a transformer located near the cut, the feed cables from the power circuit to the car being wound on a retractile reel in the cab and drawn in or paid out as the cut advances. The wiring in the car is enclosed in conduit, and is well protected from moisture and mechanical injury. The chief objection in the past to electrically operated shovels has been the possibility of damage to the hoist motor when stalled, due to the bucket digging in too deep, or striking a rock or other obstruction in the bank. The heavy current taken at such times 542 HANDBOOK OF EARTH EXCAVATION was apt to cause a burn-out, while if the motor was properly protected by fuses or circuit-breakers, their continual opening caused annoying interruptions of service. This difficulty has been overcome by the use of automatic magnet switch control, which protects the motor against such overloads by cutting resistance into the circuit when the current exceeds a certain value. The motor driving the thrust may be operated either by a drum controller or by automatic magnet control. The motor and its controller must be of such a design that the motor will be able to develop a heavy torque for short intervals of time while standing still, or rotating very slowly. Its duty is to jam the dipper against the bank and hold it there while the hoist operates. As soon as the dipper strikes the bank the thrust motor ceases to revolve, except very slowly, but must still exert full torque in order to keep the dipper against the face of the cut. Its characteristics should, therefore, be such that it may be stalled frequently for a minute or more at a time and still keep developing full-load torque without injury. The motor driving the swinging boom may be operated by hand control if provided with a magnetic brake to stop the motor quickly and keep the circuit-breaker from opening if the motor is reversed quickly; or may be operated by automatic control without a brake. The operator can place the bucket with greater precision and ease with the automatic control on account of the rapidity with which the magnet accelerates the motor. The controller panels and switches are placed in the rear of the car, while the faster switches or drum type controllers are placed in the front within easy reach of the operator. This makes a very compact and accessible equipment. Perhaps the most promising field for electric shovels is in con- nection with electric traction lines, where electric power is usually available at a very low rate. For this service they are mounted on standard gage trucks equipped with air brakes, and may be hauled on the regular tracks, or may be equipped with a trolley and made self propelling, the maximum speed being about 5 miles per hr. Great economy can also be effected by the use of electric shovels in any territory where coal is hard to pro- cure and water power is comparatively cheap, as experience has shown that with current at 2 ct. per kw.-hr. or less, their cost of operation is only about half that of steam shovels. And as part of this saving is obtained by decreased labor costs, and the cost for power is only about one-third the total cost of operating the shovel, local circumstances may determine a saving at con- siderably higher power rates. r Y/K-iii -l i ' COSTS WITH STEAM AND ELECTRIC SHOVELS 543 Operating Costs. While the initial cost of electric shovels is more than that of steam shovels, their operating cost is usually, less. They can ordinarily be operated by a smaller number of men; the hauling of coal and water is dispensed with; their power economy is greatly superior to that of the steam shovels, and they can be handled with greater precision and rapidity. In addition the electric shovel is comparatively noiseless in opera- tion, which is a great advantage for city use. Some interesting data in regard to the cost of operation of electric shovels has been obtained by the Vulcan Steam Shovel Co., of Toledo, O. One of these shovels has been operated by the Milwaukee Electric R. & Light Co. for several years, at a consumption of approximately 100 kw.-hr. per 10-hr, day. It is used for loading gravel at a gravel ba"nk and is operated by two men, who load from 300 to 400 cu. yd. of gravel per day. The average daily expenses of operating this shovel are: One engineman $2.00 One craneman 1.75 Electric power at 1.5 ct. kw.-hr 1.50 Oil, waste, repairs, etc 0.75 Total per day $6.00 The Chautauqua Traction Co., of Jamestown, New York, has been operating a shovel equipped with a 75-hp. hoist motor, since 1907. This shovel is used in loading a mixture of gravel, sticky clay and sand, which is very hard to dig, and is operated by 2 men on the shovel and 2 pitmen. The current consumption on a special test averaged 163 kw.-hr. per 8-hr, day, and 534 cu. yd. of material were loaded in an average day. The total expenses per day, including the pitmen, were $8.80, or approxi- mately 1.7 ct. per cu. yd. The maximum capacity of this shovel is about 1,000 cu. yd. per 8 hr. If operated at this capacity, the power consumption would be increased in proportion to the out- put, but the labor charges would be the same as figured in the above statement. This would bring the cost of shoveling down to about 1 ct. per cu. yd. Comparison of Cost of Steam and Electrically Operated Shovels. Where the cost of electric energy is very low, or where the smoke and sparks of a steam plant constitute^ nuisance, as in a city, the substitution of electric motors for the steam power plant on shovels is profitable. Electric ' shovels may be divided into three classes : ( 1 ) the friction-electric, whicli is operated by a single constant-speed motor with friction clutches; (2) the three or four motor direct-current equipment; (3) the three or four motor alternating-current equipment. The friction-electric shovel, according to Mr. H. W. Rogers in Engineering News, Mar. 19, 544 HANDBOOK OF EARTH EXCAVATION 1914, does not compare favorably with the other two classes as far as speed is concerned, although it may be operated as cheaply. The saving in operating cost of the electric shovel over the steam shovel depends on the comparative cost of coal and elec- tric power, and will vary for different localities. However it should be remembered that an electrically operated shovel elimi- nates the fireman, watchman, coal passer, teaming for ^ dav, the use of water, and considerable waste. Assuming that the shovel working year consists of 150 days, and that the shovel is working but one shift a day, the following is the approximate comparative cost of operation of steam and electric shovels. Labor per shift Steam. Electric Shovel runner \ $ 6.00 $ 6.00 Craneman 4.00 4.00 ' ' Fireman 2.50 Six pitmen at $1.75 10.50 10.50 One watchman 1.75 One coal passer 1.50 Teaming (% day) 2.50 Oil and waste 1.50 0.75 Total labor $30.25 $21.25 -Electric Direct Alternating Steam current current Interest at 6% $ 5.20 $ 7.75 $10.85 Depreciation at 4%% 4.03 6.00 8.43 Repairs at 10%- 8.66 Repairs at 6% 7.75 10.85 Labor per shift 30.25 21.25 21.25 Total exclusive of power. $48.14 $42.75 $51.38 The above is based on the following first costs of shovels: Steam shovel, $13,000; direct-current electric shovel $19,400; alternating-current electric shovel $27,000. Revolving Electric Shovel on Street Railway Work. The following is from Electric Railway Jl., Dec. 2, 1911: For exca- vating trenches for new and rebuilt tracks, the United Railway Co., of St. Louis, Mo., used a Thew No. (18-ton) electric shovel with a %-yd. dipper. In the suburbs in ungraded streets, where the digging is to depths of 3 or 4 ft., the truck on which the shovel is mounted is self-propelled on 4-ft. sections of tem- porary track, moved from the rear to the front of the shovel as the work proceeds. Where a shallow trench is being excavated, the shovel must be moved forward frequently, and therefore a special cradle for carrying the shovel truck over the trench on temporary track, laid in advance, was devised. This cradle and truck is illustrated in Fig. 69. The cradle was built of 10-in. channels and equipped COSTS WITH STEAM AXD ELECTRIC SHOVELS 545 with four 12-in. double-flanged wheels. It is bolted to the track. When supported by this device the propelling mechanism of the shovel was useless. Therefore a push car, fitted with axles having wheels set at both standard and 10-ft. gage, was used to move the shovel. A trench 21 in. deep and 7.5 ft. wide, was excavated at the rate of 300 lin. ft. or 146 cu. yd. in 10 hr., under city conditions. Blocking for Second Track of Double Track when Devil u Strip is Excavated. -Electric-Sh Cradle bolted to Track ol Electric Excavation in i Devil Strip. v rench for New Track -{ 7'6"wide. 2l"deep. 1 !>J End View showing Position oi Shovel on Truck. Fig. 69. Special Truck for Automatic Shovel Power Consumption of Electric Shovels. For excavating gravel for the construction of a dam across the Carson River at Lahontan, Nev., a Bucyrus, 21^-yd. dipper, electric shovel was employed. This machine, its performance and power consump- tion were described by Mr. C. E. Hogle in Engineering News, Jan. 23, 1913. The hoisting machinery was geared to a 115-hp., 440-volt, 3- phase, 60-cyele, variable speed induction motor which also pro- pelled the shovel. The swinging gear and the thrust mechanism were each driven by a 50-hp. motor. In addition, there was a 2-hp. motor that furnished power to an air compressor which supplied air for brakes. On the rear of the shovel were three 90-k.v.a., single-phase transformers which stepped down the line voltage from 2,300 to 440. Current was supplied to the shovel through 700 ft. of triple conductor cable, armored with D-shape steel tape. This was laid on and dragged along the ground. In order to get some definite data regarding the performance and power consumption of this shovel, a test was made at Lahontan, Xev., on the morning of Oct. 14, 1912. A polyphase recording watthour meter, a polyphase curve-tracing wattmeter, a curve-tracing ammeter and a voltmeter were installed in the 2,300-volt circuit supplying the shovel. The speed of the paper 546 HANDBOOK OF EARTH EXCAVATION in the curve-tracing ammeter was 10% in. per min., while the speed of the paper in the curve-tracing wattmeter was 11 in. per min. The different operations of the shovel were noted by a separate observer, who signaled to the instrument observers and also timed the different operations with a stop-watch. The shovel was working in a gravel bank 10 to 12 ft. deep, and the clear lift of the dipper was 16 ft. The conditions of the work were not favorable to making a test for determining the maximum excavating capacity of the shovel. Only two six-car trains could be spared for the test, and no attempt was made to adjust the train length to the material to be excavated. The shovel has, however, been operated at very nearly four cycles per minute, a cycle being a dipper load. The tests lasted throughout six trains of six cars each and current and wattmeter curves were taken throughout the whole time covered by these six trains, thus giving a complete record of every operation. Only the curves for train No. 12 are shown in the accompanying figures. During the test'of train No. 12 the voltage varied between 2360 and 1960. The data derived from these tests are grouped in the accom- panying table. ELECTRIC SHOVEL TEST U. S. RECLAMATION SERVICE- TRUCKEE-CARSON PROJECT Lahontan, Nevada, Oct. 14, 1912 Maximum peak per train Am- peres at kilo. 2,300 v. watts Time in minutes Cycles No. train No. cycles Cubic yards required to load per minute trains 9 12 24 4.08 2.94 10 12 24 4.57 2.62 11 12 24 4.75 2.52 12 12 24 4.00 3.00 13 11 22 4.00 2.75 14 12 24 4.50 2.67 Totals and 71 142 25.90 2.75 226 259 236 225 252 238 rrr.j;fjoD Highest average kws. per cycle 112 120 118 102 126 Power consumed loading trains kw.hr. 6.22 7.68 6.75 6.40 7.12 6.15 6.72 averages Total time elasped from start of train No. 9 to end of train No. 14 45.5 min. Total time of loading trains 25.9 min. Total time of delays, moving up, waiting for cars, etc 19.6 min. Digging and loading period is 57% of total time. Delays, moving up, etc., is 43% of total time. On the above basis the amount of gravel excavated per 8-hr, day is 1,500 cu. yd. of loose gravel. Total power consumed by six trains is 42 96 kw.-hr. or, 7.16 kw.-hr. per train. Total number of trains per 8-hr, day = 63 3. Power consumed by shovel prr 8-hr, day nr 453 kw.-hr. Power consumed per cu. yd. of loose gravel = 0.302 kw.-hr. Cost with Electric Shovel. The Chautauqua Traction Co., Jamestown, N, Y., used a Vulcan electric shovel during 1908 for COSTS WITH STEAM AND ELECTRIC SHOVELS 547 excavating ballast. This machine was described in Engineering and Contracting, Jan. 6, 1909. Complete, it weighed about 40 tons. Power was furnished through three variable speed, D. C., 600 volt, 700 rpm. motors. The hoisting motor was 75hp., and was provided with an automatic magnetic controller and circuit breaker for throwing off the current when extraordinarily hard material was encountered, thus preventing any danger of the motor stalling and burning out. The swinging gear motor was 30-hp., and the crowding engine motor was 30-hp., also. Mr. A. N. Broodhead, president of the road, is authority for the following cost data. 1 man $0.33 1 man 0.25 2 men, at 15 ct 0.30 20,346 K. W. hr. at .0088 ct 0.18 Oil and waste (estimated) . . . 0.04 Total cost, per'hr $1.10 The amount excavated each hour was 66% cu. yd., giving the following costs per day: 8 hr., at $1.10, $8.80. 8 hr. at 66% cu. yd., 534 cu. yd. $8.80 divided by 534 cu. yd., 1.64 ct. per cu. yd. for loading. The material excavated was a mixture of gravel, sticky clay and sand, which made it hard to dig, but as will be seen from the above figures, the cost of this work was very low. There are, of course, several causes for this, the principal ones being, first, that as the shovel requires no boiler, the cost of a fireman and of hauling coal and water are eliminated; second, that the work of the shovel was so intermittent and when the shovel was idle no power was being consumed as would be the case with steam shovel. The -shovel could have been operated to its maxi- mum capacity, which would have given twice the yardage, at nearly the same cost as the men had to be paid whether they were working or idle, and the additional cost for power would not have been more than twice what it was which, on the same basis, would mean 1,068 yards at a cost of $10.24, or less than 1 ct. per cu. yd. Revolving Electric Shovel in a Gravel Pit. In Engineering and Contracting, July 22, 1908, were published data relating to the cost of operating a Thew No. 1 electric shovel, owned by the Brautford & Hamilton Electric Railway, Canada. The ma- chine weighed 25 tons, was furnished with a 1 cu. yd. dipper, and was equipped with a 35-hp. motor. Two men composed the operating crew. The conditions under which this shovel was worked were most favorable. It worked in a gravel pit, the depth of the cutting 548 HANDBOOK OF EARTH EXCAVATION being about 14 ft. The material was very easy to handle. The pit was very long, so the shovel did not need to be shifted often, and inasmuch as it makes a complete swing, the time of shifting was very short. A special trolley wire was used for the motor in the shovel, so that the current was constant. No time was lost in moving the shovel ahead, as two men working in the pit would clean out a space directly in front of the shovel, when the machine would pick up a section of track in the rear and place it in the newly cleaned space. While the two pitmen were fixing this piece of track the shovel would take gravel from the side, so that not more than a minute was required to move the shovel ahead. The company had an ample supply of flat cars on each of which were loaded 14 cu. yd. loose measurement. There were also plenty of motors to haul the trains away, six cars making up a train. One motor oar was used to spot the cars continuously, and a man was employed as a signalman to* assist in spotting cars. The shovel worked *a 10-hr, shift, and any repairing and over- hauling was done at night by another crew. Operating in this manner, as a rule, the shovel was loading the maximum time, there being but little time lost in placing cars under the dipper and in moving ahead. With the electric current no time was lost in taking supplies of water and fuel. The trains that carried the gravel away were operated by a motorman and one other man. A plow, pulled by the motor car, was used to unload the cars, and two men were kept on the dump to handle the cable of the plow and to attend to other details. Owing to the large supply of cars and motors, to the favorable conditions in the pit and the method of operating, the output of the shovel per day did not vary much. A great many days 100 flat cars were loaded each day and hauled away. This meant an output of 1,400 cu. yd., loose measurement, or 1,050 cu. yd. place measurement. The labor cost of operating per day was as follows: Superintendent $4-00 Shovel Crew: 2 shovelmen 6.00 2 pitmen 3.00 Spotting Cars: 1 motorman , 3.00 1 signalman 1.50 Transporting (2 trains) : 2 motormen 6.00 - , 2 trainmen 3.00 D m 2 men 3.00 Total'per day $29.50 COSTS WITH STEAM AND ELECTRIC SHOVELS 549 With 1,050 cu. yd. moved per day we have the following unit cost for labor: Superintendence $0.004 Loading 0.013 Transporting 0.009 Dumping 0.003 Total per cu. yd $0.029 To this must be added charge for power, plant charges, re- pairs and track work. When the haul increased in length addi- tional trains were added, so that the shovel was still kept busy loading the cars. On some days the output fell to 80 car-loads or less. With this output, namely 800 cu. yd. place measurement per day, the unit labor cost was: Superintendence $0.005 Loading 0.017 Transporting 0.011 Dumping 0.004 Total per cu. yd $0.037 The above show low records of cost for steam shovel work, but they make evident the economical features of excavating with a shovel of this type, as small and inexpensive crews are em- ployed, and a comparatively large output can be obtained by using the best methods of operating. Electric Shovel on an Electric Railway. The shovel used was a 14-B Bucyrus electric operating at 575 volts. A 30-hp. hoist motor and two 15-hp. swing and thrust motor equipment used on this shovel with a %-cu. yd. dipper. The shovel weighs 19 tons. The work recorded was on the electric lines of the Wilkes- Barre Ry. Co., and the data given here are taken from the Excavating Engineer for January, 1915, and rearranged by En- gineering and Contracting, Feb. 17, 1915. Handling a 3,500-cu. yd. Slide. In May, the shovel tackled a 3,500-cu. yd. slide on the short line on Harvey's Lake Division. Work was started April 19 and was completed on May 8. The material removed was hardpan, loosened by the action of the frost. It contained a considerable amount of gravel and small boulders. The latter running in size up to 2 and 3 cu. ft. When dry this material answered perfectly the definition of hardpan. In the winter months, the frost penetrated this slope, which varied from 20 to 60 ft. in height above the track for a distance of about 1,000 ft. In the spring when the frost came out, a layer of this material, averaging perhaps 1% ft. in thickness, slid down the slope, covering one of the tracks to a depth of from 550 HANDBOOK OP EARTH EXCAVATION 2 to 10 ft.; the outside track was kept open by hand with some difficulty. When this material was dried out somewhat, the shovel was started at the end of the slide, operating from the covered track and loading into cars on the outside track. Two motor cars and two 10-yd. all-steel Western side air-dump cars were used. One motor car was used for spotting one car, while the other motor car was hauling the other car to and from the dump. The distance to the nearest switch was about 800 ft. and the shovel was idle while the spotting car was taking the loaded car to the switch and returning with an empty. On this account considerable time was lost. The record of a typical day's run shows that the shovel was in actual operation 225 min. out of a 10-hr, day. The material was hauled an average distance of about a mile and dumped along the fills for the purpose of strengthening the embankments, and preparing for a double track. When the cars were dumped the bulk of the material was precipitated down the side of the embankment. A thin layer of ashes spread on the steel bottom of the cars before loading greatly facilitated this free dumping. Although probably not more than 20% of the material exca- vated was actually spread by hand on the dump, yet it will be noted that this part of the operation represents nearly 50% of the labor cost. Approximately 3,500 cu. yd. of material was removed in 11 working days. The work was considerably hin- dered by several trees that came down with the slide, which had to be cut up and removed. This material is particularly difficult and expensive to remove by hand, and when wet, it is almost impossible to handle by reason of it adhering to the shovels. The cost of removing a smaller slide that occurred at this location, the previous season, was approximately 50 ct. per cu. yd. The total cost of the shovel operation in this instance, as shown in the table below, including spreading on. the dumps, spotting cars, hauling, etc., was 12.15 ct., or less than one-quarter of hand labor cost. One of the principal advantages of the shovel was that the material could be handled when in a semi- fluid state, thereby making it possible to get the track in opera- tion. As an indication of the output obtained under these condi- tions, on May 4, 23 (10-yd.) cars or approximately 345 cu. yd., were loaded in 227 min., the shovel moving ahead in this time 36 ft. On May 7, 22 (10-yd.) cars were loaded in 225 min., moving ahead 40 ft. on a curve. The material weighed 125 Ib. per cu. ft. The cost of handling this slide as given by Mr. Hoffman, steam shovel engineer, was: COSTS WITH STEAM AND ELECTRIC SHOVELS 551 Ct. per Labor: cu. yd. Excavating and loading 2.1 Spotting cars Hauling and dumping Spreading on dump Total labor 9 -2 Including supervision, about 10-" Power : Estimate of power used by shovel is 160 kw.-hr. per day @ 1% ct., equals $2.40 per day, or 0.75 Power used by motor car hauling to and from dump 175 kw.- hr. per day, or , ^-80 Total for power 1-55 Repairs, supplies, etc., were negligible on this job, but assumed to average $2 per or 60 ct. per cu. yd. Ct. per Summary : cu. yd. Labor, including supervision " 10.00 Power, excavating and hauling (1 mile) - Repairs, supplies, etc Total 1215 Note. No allowance for interest and depreciation on equipment. Cost of Grading Side Cut. This was a sidehill cut about 800 ft. long with a depth on the center line ranging from 1 to 6 ft., averaging about 3y 2 ft. The cut on the high side ranging from 3 to 10 ft., averaging about 6 ft. The cut contained 2,450 cu. yd. The preliminary work consisted of grading a temporary roadbed parallel with and about 14 ft. distant from the center line of the permanent track. Upon this temporary roadbed the ties and rails were laid and used for hauling the material to the dump, after which the track was thrown to its permanent location. A motor car and a Western 10-yd. steel side dump car were used for hauling the material. The grade was very steep and the track in poor line and surface, necessitating slow running to and from dump. The power on this line was weak and very un- satisfactory. It is probable that the output would have been increased at least one-third, if satisfactory power had been avail- able. Generally the material was loam and good digging. Shale rock was encountered, however, in the bottom of the cut and about 25% of the material excavated was shale ranging from soft, easy digging to very hard. The time required to make the cut was 12 working days during which time the shovel work was delayed 44 hr. principally by lack of power. The material was dumped on a fill about 600 ft. in length, ranging in depth from 2 to 8 ft., averaging about 5 ft. About 200 lin. ft. of crib 552 HANDBOOK OF EARTH EXCAVATION trestle was erected over the deeper portion of the fill. On the remainder of the fill the track was laid on the original surface and gradually jacked up to grade. The cost figures follow: Labor: Total ciTyd. Grading for temporary track $ 50.00 $0.0204 Moving shovel into position 13.24 0054 Excavating and loading material 107 74 0438 Hauling and dumping material 60.74 '0247 Building crib trestle 25.00 .0102 Spreading material on dump and raising track 134.20 .'0547 Watchman (% of watchman's time charged to this job) 12.80 0052 Blacksmith 5.90 .0024 Throwing track to permanent position 30.00 .0122 Total $439.62 $0.1790 Supervision 43.96 .0179 Total $483.58 $0.1969 Power : To operate shovel, 1,260 kw.-hrs. @ 1^ ct $ 18 90 $0 0088 Hauling material, 480 kw.-hrs. @ 1% ct 7.20 .0029 Total $ 26.10 $0.0117 Summary : Labor, including supervision $0.1969 Power (shovel and train) , 0117 Total per cu. yd $0.2086 Note. No allowance for interest and depreciation on equipment. Revolving Electric Shovel on Street Ry. According to En- gineering and Contracting, July 19, 1916, in building its 79th St. line, the Cleveland Railway Co. had to do a considerable amount of excavation for which it employed an electrically driven Thew automatic shovel. This shovel is of the horizontal crowding motion type and has several other features of interest. It weighs 13 tons, and has a dipper with a capacity of % cu. yd. and a clearance height over the house of 12 ft. 2 in. It is mounted on regular ca. wheels on which it travels on the car tracks and in addition is equipped with a set of auxiliary traction wheels, 33 in. in diameter, and 15-in. tread, which permits it to run under its own power over the ground, pavement, or wherever it is desired to take it. The entire motive power for traction, hoisting and swinging consists of one 20-hp. Westinghouse compound-wound 550-volt direct-current motor with a starting and reversing control equip- ment. The motor operates at approximately constant speed, the various motions being controlled through suitable friction and gears. The current is usually admitted to the shovel through COSTS WITH STEAM AND ELECTRIC SHOVELS 553 a flexible insulated cable connected to a switch on the truck frame and transmitted through copper rings to brushes sus- pended from the swinging turntable. The use of one motor appears to be a particularly desirable feature for reducing the initial cost and affording greater flexi- bility of action in the frequent reversals of the various operating motions; it also means the operation of three levers instead of three separate controllers, and a gain in time over starting and stopping three separate motors. It is distinctly a one-man ma- chine. The boom is of the jackknife type with an adjustable section that can easily be located, allowing the shovel to pass under the trolley wire, without interfering in any way with the effi- ciency of its operation. The shovel swings through a complete circle, delivering the excavated material at any desired point. A buffer is furnished which takes up the shock that occi.rs when the shovel strikes a hard piece of excavation. This allows the shovel to be released and relieves the whole machine from the strain to which it would otherwise be subjected. Th cab is cut away so as to allow plenty of room for passing cars, a feature of particular importance when used on street railway work. The cost was: Loading: Shovel man @ 40 ct $ 4.00 Four laborers @ 21 ct -. 8.40 Current, oil, repairs, etc 1.50 Loading per day '.. $13.90 Hauling : Four men @ 26 ct $10.40 Four men @ 19 ct -. 7.60 Two men @ 30 ct 600 Hauling per day $24.00 .Dumping : One foreman @ 30 ct $ 3.00 Six laborers @ 20 ct 12.00 Dumping per day $15.00 Loading, Hauling and Dumping: Cubic yards loaded in 10 hr. May 8 510 Loading per cu. yd 2.6 ct. Hauling per cu. yd 4.4 ct. Diimping per cu. yd 2.8 ct. Loading, hauling and dumping per cu. yd 9.8 ct. Lineal feet excavated on this work . . t 2,700 Number of 10-hr, shifts operated .* 12 554 HANDBOOK OF EARTH EXCAVATION Lineal feet excavated per 10-hr, shift 225 Cubic yards loaded (place measure, per 10-hr, shift) 450 Average loading cost, 450 yd. $13.90 3 ct. per cu. yd. Average hauling cost, 450 yd. @ $24 5 l / 2 ct. per cu. yd. Average dumping cost, 450 yd. @ $25 3 1 /-} ct. per cu. yd. Average loading, hauling and dumping cost 11% ct. Length of haul, approximately 6 miles Average hp. used in moving shovtl 15.0 Maximum hp. used in moving shovel ; 20.2 Average hp. used in operating shovel 11.7 Maximum hp. used in operating shovel 43.6 A Shovel on the Boom of a Derrick. Engineering and Con- tracting, Nov. 22, 1911, gives the following: Fig. 70 shows an ordinary revolving mast derrick with a new attachment known as the Bishop's Derrick Excavator. Fig. 70. Excavator Mounted on " A " Frame Traveler. The carriage at the base of the dipper arm is made of steel plates and contains four rollers which allow it to run up and down the boom. Between the two side plates and below the rollers is a cross channel, from which is suspended, by bolts two plates, one above and one below the stationary wire cable which is attached to the boom at the heel and peak. On these plates are cast iron grips to hold the carriage to the wire when desired. The end of the dipper arm is provided with a cast iron eccentric or cam shaped shoe and when the dipper arm is raised towards the boom as shown in its dumping position, the pressure is re- leased, and permits the carriage to roll on the boom, but when the dipper arm is released, as shown in the digging position, the large end of the cam or eccentric presses the lower grip plate against the wire and holds the carriage until the dipper arm has been raised sufficiently, when the small end of the cam or eccentric releases the grip, and the carriage follows up the boom. COSTS WITH STEAM AND ELECTHIC SHOVELS 555 The automatic dumping arrangement is shown in the illustra- tion. This is a lever arm rigidly attached to the carriage, which acts on the lever shown attached to the dipper arm. When the dipper arm is brought almost parallel with the boom these levers come in contact and the door latch on the dipper is caused to be pulled back, thus releasing the bottom of the dipper. One man is required to operate the shovel with a two-drum engine and swinging gear. One drum is required to raise and lower the boom and the other to operate the shovel. The operator slacks on the digging line until the carriage rolls down the boom, bring- ing the shovel to the desired position. He then releases entirely Fig. 71. Keystone Excavator Equipped with Skimmer. Boom Raised and Bottom of Skimmer Dropped as When Dumping. and the shovel swings back under the boom, the cam operates the grip holding the dipper arm rigidly from sliding in the boom and at the same time the boom is lowered and its weight is brought onto the dipper. The weight of the boom is allowed to rest on the shovel which it is digging. The excavator is made by the Union Iron Works, Hoboken, N. J. The Keystone Traction Excavator. Engineering and Contract- ing, May 27, 1914, gives the following: For the Keystone exca- vator three different types of scoops are provided, namely, a dipper, Fig. 72; a skimmer, Fig. 71, and a ditcher scoop, Fig. 73. All three scoops are about equal in capacity, holding approxi- mately two-fifths of a yard, and can be operated at about the same speed, two to three times a minute in free digging. 55G HANDBOOK OF EARTH EXCAVATION The " skimmer scoop " has a flat bottom. It is used largely in street grading and for comparatively shallow excavation. It is carried on rollers which slide along the 16-ft. boom. When the skimmer type of shovel is to be used the dipper sticks are removed and the tackling changed. The form of the scoop makes it possible to have a smooth, level, finished surface in grading. Since the skimmer scoop can be moved 11 ft. along the boom, its operation in digging is like that of a drag scraper. The ditching scoop differs from the dipper and skimmer in Dipper Bucket for Keystone Excavator. shape and is employed in making ditches for sewers, water mains, etc. It is good for a width of 15 in. to 44 in., and a depth of or 8 ft. The best record with this type of scoop was made by S. B. Markley, contractor of Woodlawn, Pa., on work at Conway, Pa. He dug in eight hours 400 ft. of ditch 4^ to 5 ft. deep and 36 in. wide at the bottom. In ditching work the action of the dipper scoop is reversed, the scoop being carried on a hinged arm at the extremity of the boom, and the machine being moved backward as the ditch is completed. The dipper scoop is similar to the ordinary steam shovel. The best record hitherto achieved with the dipper scoop was 142 loads, COSTS WITH STEAM AND ELECTRIC SHOVELS 557 dump wagons of 1^-yd. capacity being well filled, in 6^ hours' running time. For short periods wagons were loaded at the rate of one in each one and a quarter minutes. Two men are required to manipulate the machine. The boiler is 36 x 69 in. and is of the inverted porcupine style. The engine is 8 x 8 in. The weight of the complete machine is about 16,000 Ib. Its traveling speeds are 1 and 3 miles per hr. The machine is made by the Keystone Driller Co., Beaver Falls, Pa. Fig. 73. Ditcher Bucket Equipment for Keystone Excavator. Bibliography. " Steam Shovels and Steam Shovel Work," E. A. Herrman. " Handbook of Steam Shovel Work," Published by the Bucyrus Co., South Milwaukee, Wis. " Excavating Machinery," A. B. McDaniel. "Cost Data," H. P. Gillette. " Steam Shovel Work on Summit Division, Chicago Canal," E. R. Shanable, Jour. Asso. Eng. Soc. Vol. 14, June, 1895. " The Application of Electric Motors to Shovels,"' W. H. Rodgers, Trans. Am. Inst. M. E., Feb., 1914. " Giant Revolving Shovel Used at Gravel Plant," Engineering Record, Aug., 1916. "Second Track Construction and Improve- ment of Line and Grade from Madison to Baraboo, Wis.," Eng. News, June 3, 1897. " Progress of the Excavation Work for the Pennsylvania R. R. Terminal in N. Y. City," Eng. A 7 ., Nov. 10, 1904. " A Method of Determining Slopes in the Bench System of Steam Shovel Operation," Eng. and Con., Mar. 22, 1911. I CHAPTER XII METHODS AND COST WITH GRAB BUCKETS AND DUMP BUCKETS For the purpose of a study of methods and cost of handling earth in buckets the following classification will be adhered to : Hoist .Buckets (Chapter XII). a. Non-Digging Dump Buckets. 1. Skips. 2. Trunnion Buckets. 3. Bottom Dump Buckets. b. Digging or Grab Buckets. 1. Orange Peel Buckets. 2. Power or Clam-Shell Buckets. Drag Scrapers or Buckets (Chapter XIII). a. Non-lifting power scrapers. b. Lifting dragline buckets. Hoist buckets are suspended from derricks, cableways, or loco- motive cranes and are accordingly suitable for a wide range of uses. Consult the " Handbook of Construction Plant," by R. T. Dana, for designs, prices, etc. of derricks and buckets. Skips. These are trays or shallow boxes with one side open, Fig. 1. They are of wood or steel, and are suspended from three points by chains leading to a ring which is engaged by a hook and suspended from the derrick. . , .I'miii' Fig. 1. Wooden Skip. J ,wttih*VSr Kioit plM&'bnA wtivi U jnwi Cost with Skips. In foundation work it is frequently neces- sary to use a derrick for handling the earth. Either wooden " skips " or iron buckets are filled with earth by shovelers, and a man-operated, horse-operated, or power-operated derrick is used to lift the buckets out of the way. 558 COST WITH GRAB BUCKETS AND DUMP BUCKETS 550 Work of this character is always expensive for only a few shovelers can be worked ra the pit, and as a consequence the derrick is never worked to its capacity. The following was the cost on one job : A stiff-leg derrick with 35-ft. boom, and three wooden skips (1x4x4 ft. ) constituted the plant. A team with driver was used to raise the skips. The output in soft digging per 10-hr, day was 100 cu. yd. 'd D->K') o.t rj'Mji it *>j \- fuo'il ba'^kjtfisi 6 men loading skips at $1.50 $ 9.00 1 man in pit hooking on skips 1.50 2 tagmen swinging and dumping 3.00 1 team with driver 3.50 1 foreman 3.00 100 cu. yd. at 20 ct ! $20.00 This was an excellent record, but the digging was fairly easy. Four skips made a 1.5-cu. yd. wagon load, and it took 1.5 min. to load, hoist, swing and dump a skip, half of which time was occupied in swinging the derrick boom out and back. The setting up of a small derrick of this kind will take a crew of men 3 hr. or less if the foreman knows what to do, but we have known green foremen to be all day getting the derrick up. Where there are trees to anchor to, a guy-derrick is to be pre- ferred, for there are not several tons of stone to be handled as on a stiff-leg derrick which must be weighted down. Moreover a guy-derrick is quite easily shifted a long distance even while standing. Some contractors set the foot of the mast of a guy- derrick on a framework that rides of skids, and it is then easily dragged over the ground even while upright. A hand winch is never to be used if it can be avoided, for it is too slow a method for moving earth. Wagon boxes of special design are sometimes made to be lifted off the wagon bed with their load of earth and dumped into scows. Wooden skips with two sides only might be loaded by drag scrapers, then lifted by a derrick and dumped directly into wagons or into a bin from which the earth could be drawn off into wagons. Foundation Excavation with Derrick and Car- Bodies. The construction of an addition to the power plant of the Indiana Michigan Electric Co., South Bend, Ind., was described in En- gineering and Contracting, Feb. 28, 1912. The excavation for each foundation was 36 ft. square, and was carried down 30 ft. The pit was tight sheeted with 2xl2-in. plank, double lapped. The material encountered in the excava^ tion consisted of sand and gravel, to a depth of about 20 ft., and then of clay to 5 ft. in depth. From this point down there was blue clay, with an occasional pocket of quicksand. The 560 HANDBOOK OF EARTH EXCAVATION sheeting was driven by hand, as the excavation progressed, by two men who were employed at this work continuously. The material was excavated by hand and shoveled into the body of a %-cu. yd. car. This body was V-shaped, and was fitted with legs so that it could stand upright on the ground, or could be used on the car. A 3-way chain was rigged so that the car body could be swung from the derrick. In the pit were employed from 4 to 6 men to each bucket, and each man averaged about 3 cu. yd. of earth per day. There were 4 or 5 buckets used in the pit. Trunion Buckets Loading Wagons Through a Hopper or Table. J. C. Black, in Engineering and Contracting. Dec. 11, 1907, gives the following: The work was the digging of a base- ment in Portland, Oregon. The property was a corner lot 100 ft. square and nearly level, and had been occupied by some frame buildings at least one of which had a cellar and stone foundation. About 8,000 cu. yd. of material were handled, the average total depth being about rt-Z Eng-Contr Fig. 2. Method of Filling Buckets. 20 ft. Almost the entire excavation was a mixture of yellow clay and sand with a small amount of loam. Excavation was begun at the inner corner of the area and was rapidly carried to full depth at that place, thus affording a steep bank against which to work. A crane lifted the material from the pit in buckets, and dumped it on a table or tipple from which it was loaded into wagons. A bucket to be filled was placed against the face of the bank, COST WITH GRAB BUCKETS AND DUMP BUCKETS 561 as shown in the sketch, Fig. 2, and was loaded partly by shovels, partly by material picked from the face so as to fall into the bucket and partly by slabs or spalls of earth pried from the top of the bank with a crowbar. This last method was exceedingly effective, for the earth broke off easily, and one man with a bar at the top of the bank could loosen large pieces with compara- tively little effort. Sometimes enough earth to fill a bucket would fall at once, while that which fell outside the buckets was in a condition to be easily handled by shovels. It is probable that this method of prying from the top of bank would prove uneco- nomical for some classes of material, but in this material it worked well. The crane consisted of a 35-hp. hoisting engine and a wooden derrick frame mounted on a timber sledge. The maximum reach of boom from center of rotation was 30 ft., but, by Ibwering a bucket almost to the ground and then having it set swinging by the men in the pit, it was possible to drop it some 20 ft. beyond the end of the boom, thus affording a maximum working range of 80 ft. from point of loading to dump. \Yhen necessary to remove the crane to a new position on the work, a cable was made fast to something which would serve a.s an anchor and it was made to move itself. Rollers were gen- erally used under the sledge. An . hour to an hour and a half was the time consumed in moving. Axles on which could be placed a pair of rear wagon wheels were fitted to the sledge near one end, and at the other was a place for the forward truck of a wagon, thus making transportation from one piece of work to another a very easy matter. The 5 buckets were made in Portland. The nominal capacity was 35 cu. ft. each. They were dumped by tilting; the catch which held them upright being released by the man at dumping table. This table (Figs. 3 and 4) or tipple was the most inter- esting feature of the plant. It consisted essentially of a steel frame supporting two trays under which the wagons to be loaded were driven. The trays are each about 1 ft. deep, 4 ft. wide and 6 ft. long, and when closed, met at the center forming one large tray. In dumping, each tray rotated about an axis of its own near its center, the weight of the earth causing it to dump automatically when released, and the position of its own center of gravity making it automatically return to a horizontal posi- tion after having emptied its contents. Its effect was to " trim " the load so that little or no work was required to spread it on the wagons, while the amount spilled was negligible. It will be seen at once that the table affords a storing place for materials, and thus reduces the lost time due to irregularity 662 HANDBOOK OF EARTH EXCAVATION in arrival of wagons. Usually only one bucket of earth was placed upon the table at a time. A record of wagons was kept by the dumpman with pegs on a tally board mounted on'the table. Of course this loader was not so near perfection but that it was occasi6nally necessary to clean up around it, especially as it was Fig. 3. Plan, Front Elevation and Side Elevation of Dumping Table. a busy street. However, it reduced work of that nature to a minimum. When necessary to shift the position of the table, a timber yoke was fastened to the frame by chains, and the whole thing was moved by the derrick. Light for the night crew was supplied by three clusters of six 32-c.p. incandescents each, backed by reflectors. COST WITH GRAB BUCKETS AND DUMP BUCKETS 563 'nnK^^f "" ^SL IA *=^ $Pi 'alSIiSSgP* ~' ttV* >'*1- -" T'^ J- 4 HrF' h fa J 5 !fe PPr M vM : ^ nL ioS ! ij. fo So 1 4J^ i ; . ji | jf t H Studebaker dump wagons were used, and, by an extension to the top, they were made to hold 2,y 2 cu. yd. each when level full; which shows that two buckets of material were required per load. The cost of the plant was approximately as follows: Locomotive crane (including cable) $4 500 Five buckets at $145 725 Loading table 500 Total (exclusive of small tools) ^5,725 504 HANDBOOK OF EARTH EXCAVATION Two crews of equal size were employed most of the time, a total daily force being about as shown in the table. The rates of wages are assumed, and would, of course, vary from time to time, and with location. Two foremen, at $4 per day $ 8.00 Two engineers, at $4 per day 8.00 Two firemen, at $2.50 per day 5.00 Two signalmen, at $2.50 per day 5.00 Two hook tenders, at $1.75 per day 3.50 Two dumpmen, at $1 .75 per day 3.50 Thirty laborers, at $1.75 per day 52.00 Total daily wages $85.50 One man sometimes acted as both signalman and hook tender. Assuming other daily expenses, we have: Labor $85.50 Fuel, oil and supplies 5.00 ^Repairs 5.00 Total $97.50 The average daily output was 500 cu. yd. for the two crews, which gives a cost per cu. yd. of nearly 20 ct., loaded on the wagons. Each of the 30 laborers, therefore, averaged nearly 17 cu. yd. per day. The following details are from data obtained by personal ob- servation at various times: LOADING BUCKETS (All Buckets Filled Heaping 35 Cu. Ft. Struck Measure) Bucket Labor Time No. Min. Sec. 1 3 men shoveling 3 50 2 4 men shov.eling 4 3 3 men shoveling '. 5 4 3 men shoveling and picking 5 30 5 2 men shoveling, 1 man picking 4 55 6 3 men shoveling 3 45 7 2 men shovding and picking, 1 man barring from top...... 3 15 8 2 men shoveling, 1 man picking from face into bucket 4 00 9 1 man shoveling, 2 men picking from face into bucket 10 2 men shoveling, 1 man picking and barring 3 45 11 1 man shoveling, 1 man picking into bucket, 1 man barring 3 12 2 men shoveling, 1 man barring down from top 5 Total, 28 men shoveling, 10 men picking and barring 50 53 Average 2^j men shoveling, 5-6 men picking and barring 4 15 This is equivalent to a bucket of earth loosened and loaded by one man in 13^ minutes. Data on time consumed in handling buckets are as follows: . : ' ....'.. -.foot uiyiT> !o"V/r?n'h/-f>) |&toT COST WITH GRAB BUCKETS AND DUMP BUCKETS 565 P. .j 5 Seconds of time !*S i3 Total time for handling one bucket. No. 1. 3... 4.. 5. . 6... 7. . 9... 10... 11... 11 buckets handled Average .......... AU 43 45 60 38 37 50 62 43 44 45 42 509 15 17 20 18 18 18 15 17 16 15 18 187 17 13 8 10 14 12 8 10 15 10 20 19 139 13 Si* 12 10 15 18 10 12 10 10 15 11 18 141 270 270 200 200 270 270 240 240 270 200 200 This indicates that the time required to handle one bucket is approximately \y 2 minutes, so that barring delays 40 buckets of 52 cu. yd. would be the maximum hourly capacity of the crane. The owners of the plant are much pleased with its operation and are going to give it a trial with three 8-hr, shifts. It will be seen that the plant is of low first cost, is adapted to the handling of a variety of materials, is economical of time, and affords a great saving in the wear and tear on teams and wagons which results from hauling out of an excavation. This last point is considered by Mr. Cook to be the greatest advantage of the system. Bottom Dump Buckets. These are more suitable for handling concrete than earth. Where present on a job for the former purpose they are often used for removing the hand excavation to neat lines. For this work they possess no advantage over skips. Three Types of Buckets on Sewer Work. According to En- gineering and Contracting, June 29, 1910, bucket excavation was employed in digging 2,723 ft. of the Northwestern Trunk Sewer at Louisville, Ky. The main plant for this contract consisted of three ten-ton Browning locomotive cranes, two of which were equipped with automatic buckets. One orange-peel of 1 cu. yd. capacity and one clamshell of % cu. yd. capacity are used. The cranes run on standard gage track of 60 and 65-lb. rails The track is laid along the trench for 600 ft. On account of there being plenty of good sand in the trench, it is screened and used for the con- crete. The screen used consists of a framework placed opposite 566 HANDBOOK OF EARTH EXCAVATION to one of the cranes. This crane dumps part of the sand into the hopper at the top of the screen and the sand and rejections are carried by chutes to separate piles 15 or 20 ft. away from the trench. In opening the trench horse scrapers were used and enough of the trench was excavated in this way, and used for filling in low land near by, to take up the amount which would necessarily have to be spoiled. An average of half a dozen teams were used on this work with one team acting as a snap team. The longest haul was about 100 yards. Excavation and Backfill. The cranes operate about as follows: Crane No. 1 is equipped with an Owens clamshell bucket and takes out the cut to a depth of about 10 or 12 ft. The sheeting is started as soon as practicable and crane No. 2 equipped with a %-cu. yd. bucket takes out the balance of the cut. The cranes dump all excavated material in a spoil bank except the sand, which is dumped on the screen by crane No. 2. Crane No. 3 brings up the rear of the work and does all the backfilling and pulling of timbers and sheeting. Progress and Costs. Progress and costs of various parts of the work are interesting. The working day is 10 hr. Crane No. 1 operates a ^-cu. yd. Owens clamshell bucket and averages 400 buckets in 10 hr. or 200 cu. yd. This bucket handles a full half yard at each operation. The labor cost on this machine is as follows: 1 engineman at $3.50 1 fireman 2.00 1 tagman 1 .75 1 signalman 1.75 Cost of labor for 200 cu. yd. (clay) $88.90 Cost of labor per cu. yd., $0.045. The second crane handles sand in a %-cu. yd. dump bucket filled by hand. It handles 300 buckets or 225 cu. yd. a day. The labor cost on this is as follows: 1 engineman '. $3.50 1 fireman 2.00 1 foreman 2.00 8 men in bottom at $1.75 14.00 Cost of labor for 225 yd $21.50 This gives a cost of labor for 1 cu. yd. of $0.095. The third or backfill crane operates a 1-cu. yd. orange-peel bucket and handles 500 cu. yd. of material in 10 hrs. The cost of labor back- filling is as follows: COST WITH GRAB BUCKETS AND DUMP BUCKETS 567 1 engineman r^ $3.50 1 fireman 2.00 1 signalman 1.75 Labor cost backfilling, 500 cu. yd $ 7.25 Labor cost per cu. yd. of backfilling, $0.0145. This crane when not backfilling, pulls timbers and sheeting. The average amount of coal used by one crane in a day is 1,200 Ib. Run-of-mine coal is used at $4 per ton. About 160 gal. of water are used per crane per day. The cranes each cost $5,000 new and their annual interest and depreciation is figured by the contractor at 30%. The average wages paid upon this work are as follows : Superintendent, per month $135.00 Street foreman, per month 80.00 Carpenter foreman, per month 80.00 Concrete foreman, per month 80.00 Timber foreman, ptr month v 80.00 Team foreman, per month " 80.00 Man in charge of all form work, per month 135.00 Timekeeper, per month 50.00 Water boy, per day 1.00 Stud men, per day 2.00 Carpenters, per day 2.50 Concrete men, per day 200 Timbermen, per day 2.00 Crane engineers, per day 3.50 Crane firemen, per day 2.00 Laborers, per day 1.75 Blacksmith, per week 20.00 Blacksmith's helper, per week ,.. .. 15.00 Teamsters, per day 2.00 Orange-Peel Buckets. These are made in two forms and in a great variety of sizes. The bucket with four segments is suitable for excavating loose material in which it will sink of its own weight. Where the material will not permit this, the orange- peel does not fill so well as does the grab bucket. The second type of orange-peel bucket is made with three segments and is most suitable for excavating where rocks and logs have to be handled. It will grapple and hang on to anything that gets between its jaws. Buckets of this type are made up to 6 cu. yd. capacity, and strong enough to handle a 10-ton rock. At the other extreme of size, four segment buckets have been made small enough to clean out 12-in pipes. Work of an Orange-Peel Bucket at Massena, N. Y. The ex- cavation for the foundations of power house was described in Engineering ~News, Dec. 15, 1898. The work was accomplished by a steam shovel working in the pit, and a land dredge with an orange-peel bucket operating from the bank. Both machines loaded into dump cars hauled by locomotives. The orange-peel 568 HANDBOOK OF EARTH EXCAVATION excavator dug 35 ft. deep in very homogeneous, cheese-like, clay. With a 1-cu. yd. bucket the daily output in 10 hr. was 600 cu. yd. The total labor cost of operation was $20, giving a labor cost of 3} ct. per cu. yd. Fig. 5. Orange-Peel Bucket Made by the Hayward Company, 50 Church St., New York. Cost of Excavating Trench with Orange-Peel Bucket. In En- gineering-Contracting, April, 1006, a detailed description is given of the plant and methods used in building a large sewer in Chicago by city forces. For part of the work a 1 cu. yd. orange-peel bucket was used. A traveling derrick, on rollers, was used. It was designed to swing in a full circle. The crew was: Per day 1 engineraan $ 4.80 1 fireman 2.50 1 signal man 3.25 s 1 powder man 3.25 2 laborers at $3.25 6.50 Total per day $20.30 COST WITH GRAB BUCKETS AND DUMP BUCKETS 569 Under ordinary conditions, the orange-peel bucket excavated about 450 cu. yd. a day, all earth being dumped on a spoil bank at one side. On the assumption that 450 cu. yd. were excavateJ per day, the labor cost was 4.5 ct. per cu. yd. About 50 Ib. of dynamite and % ton of coal were used each 8-hr. day. The cost of the dynamite was $7.50 and the coal cost $3 per ton, making the total cost for dynamite and coal $9.75. The total cost per day for excavating thus was $30.05; and the cost per cu. yd. was 6.6 ct., exclusive of the wear and tear on the machine. In this excavation the swinging derrick with the orange-peel bucket could be worked to better advantage than a steam shovel, inasmuch as it could work between the braces, which were 11 ft. centers. The bracing was placed as the excavation proceeded, and when the trench excavation was completed, the braces were all in place. By the use of the derrick the excavated material could be deposited far enough from the trench so as not to necessitate rehandling. In the case of a steam shovel it would have been necessary first to put in a temporary bracing, and a permanent bracing afterwards. Also, the boom of a steam shovel would not be long enough to deposit the excavated matter the necessary distance from the trench. Cost of Excavating Sand in Trench with an Orange-Peel Bucket. Engineering and Contracting, July 15, 1908, gives the following. In the construction of District Sewer No. 1 for the town of Gary. Ind., built by the Green & Sons Co., of Chicago, the preliminary excavation for the first 1,830 ft. was done with a Hayward orange-peel bucket of % cu. yd. capacity. The bucket 30' 0* Fig. 6. Cross-Section of Cut. was operated by a 25-hp. hoisting engine and a separate swinging engine. The machine was mounted on rollers and moved forward with its own power by means of a " dead man " ahead. The material removed consisted of fine sand of the kind preva- lent throughout the Calumet region, the last 3 or 4 ft. of excava- tion being in water. The cut was in cross section as shown in Fig. 6. The crew consisted of one engineman at $6 per day, one fore- man at $3.50 per day and five laborers at $1.50 per day who handled planks and rollers, built up runways for the machine 570 HANDBOOK OF EARTH EXCAVATION in rough ground, and smoothed up the cut and left a smooth shelf for the workmen following up the dipper. This makes a total labor cost of $17 per 9-hr, shift. The coal consumption averaged $5 per day, making a total cost per shift of $22. The work was begun April 2 and the first 1,830 ft. were com- pleted May 21, making 43 working days. The machine was shut down five days for repairs, and there was a night crew on for 13 additional shifts. This makes a total of 51 complete shifts. 51 shifts at $22 $1,022.00 5 days' extra pay for engineer and fireman (during repairs) 47.50 Cost of oil and extra help on repairs, about 65.00 Total $1,134.50 The total number of yards removed was 21,250, making a net cost of 5.3 ct. per cu. yd. Clam-Shell Buckets. These are also called grab buckets. They are made in a great variety of forms, special designs being offered by the manufacturers for almost every service. In gen- eral, an extra line besides the hoisting line is required to manipu- late the bucket. However, most manufacturers are now offering buckets that operate on a single line, a hand line being used for dumping. A single line bucket made by Edgar E. Brosius, Pittsburg, Pa., is shown in Fig. 7. It is made in the following sizes and weights : Size Weight % cu. yd. 1,200 Ib. % cu. yd. . 2,600 Ib. 1 cu. yd. 3,000 Ib. 1% cu. yd. 4,000 Ib. 2 cu. yd. 5.000 Ih. 3 cu. yd. 6,000 Ib. A similar grab bucket is made by the Brown Hoisting Ma- chinery Co., of Cleveland, O. This bucket is especially useful where frequent changes have to be made from bucket to hook. Another type of grab-bucket is handled with a single line and is equipped with a motor for opening and closing. It has the advantage of being able to dump its load gradually, an advan- tage not possessed by other single line grab buckets. Grab-buckets are more suitable than orange-peel buckets for excavating hard material. The edges are frequently provided with teeth, and the scraping action of the bucket in closing, together with its weight and the great force that can be exerted, insure good filling. The Fogarty Excavating Bucket requires an engine with two working drums, one for the hoisting line and one for the closing COST WITH GRAB BUCKETS AND DUMP BUCKETS 571 line. Otherwise it can be used on any type of crane or derrick car. It is directly attached to the derrick boom instead of being suspended. This bucket is made by Rochester Excavating Ma- chinery Co., Rochester, N. Y. Clamshell Bucket Excavation on Boston Subway. Engineering News-record, June 7, 1917, gives the following: The top 22 ft. of a timbered cut for section (J of the Dorchester tunnel in Boston has been taken out with a traveler and clamshell bucket, keep- OPENED Fig. 7. Brosius Single Line Grab Bucket, Closed Position. ing pace with two ordinary hoisting rigs removing the lower lift and requiring only a small crew for its operation. It was possible to close the street, and the traveler moved down the middle of it ahead of the cut, taking out section's 25 ft. in length at a time. The dirt was disposed of in backfill or on a rented dump by industrial cars and two small locomotives. A large A-frame derrick has taken out the greater part of the excavation in sections the full 35-ft. width of the cut, 25 ft. long and 22 ft. deep. Although this rig is equipped with a Fogarty bucket, it does not have the extra boom generally used to bear down on the bucket and increase its digging power. This 572 HANDBOOK OF EARTH EXCAVATION is not found necessary, and the derrick is rigged with a three- drum engine and swinging gear in the ordinary manner. No longitudinal braces are used in the upper part of the exca- vation, so that the bucket can be operated between the cross- braces freely. These are 10 x 12-in. pine timbers, spaced 4 to 5 ft. apart vertically and 10 ft. apart horizontally. The sides of the cut are held by 3-in. sheeting driven by hand or with a small air hammer. Poling boards are used on part of the westerly side of the cut, as there is not room to drive the sheeting outside the industrial track. The lower part of the cut is excavated by hand, loaded into ordinary skips and taken to derricks, which dump the skips into Fig. 8. The Fogarty Excavating Bucket. Note Crowding Line for Hard Surface Grading. cars. During the time covered by the cost data given herewith, two of these derricks would fill five dump cars while the traveler was filling five more. The ten cars were then hauled to the dump or to the backfill by a locomotive. The dump, which was at one end of the job, was leased, and the industrial-railroad equipment used to reach it and the backfill comprised about 3,000 ft. of track, 25 Koppel dump-cars of 1-yd. capacity and a Koppel steam locomotive, in addition to a Plymouth gasoline engine. The material excavated by the traveler consists of 12 ft. of gravel fill, a layer of peat and successive layers of sand and clay. One small brick sewer encountered and a larger brick intercept- ing sewer, which last had to be broken up with sledges, were readily removed. The crew "required with the traveler consists of a foreman, an engineman, two bracers and nine laborers. This gang could remove an average of 65 yd. of material in an 8-hr. COST WITH GRAB BUCKETS AND DUMP BUCKETS 573 shift. Accurate costs kept on this work for one month in Janu- ary and February, 1917, indicate a direct cost of $1.47 per yd. for excavating the material and placing it in backfill, which cost slightly more than carrying it to the dump, on account of the greater labor required in spreading. COST OP EXCAVATING WITH CLAMSHELL Rent of equipment, fuel $0.17 Superintendent, timekeeper, foreman 12 Labor, engimer, bracers 51 Repairs and incidentals - 03 Insurance . : 07 Lumber (bracing and sheeting) 12 Pumping Hauling equipment, rent, fuel 08 Hauling, labor, insurance 09 Lease of du mp 06 Dumping and spreading in backfill, labor, insurance.. .13 Total direct cost per cu. yd. $1.47 The figures for rental equipment given in the table assume the new cost of the entire traveler rig as $4,000, on which basis $42 per week as rent for this equipment is charged to the work continuously, whether the equipment is idle or not. The esti- mated new cost of the hauling equipment is $6,200, and $54 per week rental is allowed for it. Coal is figured at $6 per ton, the wages of an engineman at $4 per day, bracers at $3.20 per day, and labor at $2.25 per day of 8 hr. On this part of the work, lumber is used very economically, the bracing serving four times and the sheeting twice. Both kinds of lumber will have a large salvage value at the end of the job, and on this account $10 per M is charged for the lumber each time it is used. During the time these data were taken, five days were lost on account of stormy and extremely cold weather, and one day on account of repairs to the derrick. The costs, of course, are increased by frost and cold in comparison with warm weather costs for the same work. Data kept during February and March on the cost of taking out about 1,400 yd. of excavation from the lower 20 ft. of the trench, the part not excavated by the traveler, indicate a direct charge of $2.39 per yd. for handling the ma- terial in the old way. Although bad weather interfered con- siderably with these operations and the amount excavated was scarcely enough to give average figures, the result at least indi- cates that the relative cost by the traveler method is much lower than in excavating by hand. Three-quarters of the whole cost of pumping is charged to the lower portion, and all the cost of the tongue-and-groove sheeting left permanently in place. 574 HANDBOOK OF EARTH EXCAVATION COST OF EXCAVATING SECOND LIFT BY HAND Rent of equipment, fuel $0.13 Supervision 21 Labor, engineer, bracers 92 Air, hammers, repairs 13 Pumping 23 Insurance 11 Lumber left in place 27 Haul 17 Dumping 22 ' l . Total direct cost per cu. yd $2.39 Bibliography. " Handbook of Construction Plant," Richard T. Dana. " Excavating Machinery," A. B. McDaniel. " Cost Data," H. P. Gillette. " A Truck Mounting for Stiff-Legged Derricks," Eng. and Con., Feb. 7, 1912. *Mi.f'.>v ? fo'iiniJiTi '"'' J >15 n -. .>'[< 02. It consisted of a 55-ft. guy derrick, without boom, placed near the edge of the bank at the side of the river, and a two-legged bent placed in the middle of the river. The cable was of %-in. steel and was stretched from a dead man on the shore about 150 ft. back of the derrick, past and just crossing the derrick to the bent. Under the top of the bent at the end of this cable hung two weights which consisted of scale pans loaded with concrete. In passing over the bent the cableway was carried on a 16-in. block. The boom fall of the derrick was then hooked onto the cable at the foot of the mast. The carriage on the cable con- sisted of two 16-in. cable-sheaves with iron straps, forming a triangle, and carrying a chain on which the bucket was hooked. In operation the bucket was hooked to the carrier on shore, a single drum hoisting engine wound up the boom fall and the cable COST WITH CABLEWAYS AND CONVEYORS 585 was hoisted until it had a pitch down toward the river of 18 or 20 ft. ui the span of 450 ft. The loaded bucket travelled under gravity away from the shore. After the bucket had been dumped the boom fall was lowered until the cableway had a reversed pitch of 18 or 20 ft., when the empty bucket returned to the shore. Dtrritli.SSkhigh. Fig. 10. A Cableway for Conveying Materials in Building Con- crete Piers, at Northumberland, N. Y. The speed of the bucket was governed by the slope of the cable. When the cable was at its extreme grade the bucket would run from the platform to the bent a distance of 450 ft. in 35 seconds and return in about the same time. This device might be em- ployed for earth excavation. A Balanced Cable Crane. Engineering and Contracting, Nov. 13, 1907, gives the following: This cableway was installed at a coal storage plant at Watertown, N. Y. It is equipped with Fig. 11. Cableway in Which Sag in Cable is Practically Done Away with by Oscillating Towers. *"* {I I V *f *i /j ^( T i'i ' tM-ii ' i*~ oh OPO $K\ rriiri^ 4 /lif*{n" li 'MitJ'i fi electric motors not only on the trolley or carriage, but also on each of the oscillating towers. In this manner each tower can be propelled along the single rail track. It is not necessary that the two towers move simultaneously. Indeed, one tower can travel 25 ft. without moving the other tower. The towers have a traveling speed of 43 ft. per min., when it is desired to shift them. 586 HANDBOOK OP EARTH EXCAVATION The electric load carriage, or trolley, handles a 3-cu. yd. clam- shell bucket, and has a traveling speed of 1,500 ft. per min. and a hoisting speed of 80 ft. per min., with a 00-hp. motor. It is interesting to note that this cableway as built commands about 9,000 cu. yd. of material per ft. of depth. It might easily be economical equipment to use on an excavating job. A Combination Cableway and Derrick. Engineering and Con- tracting, Feb. 24, 1909, gives the following: Today the use of cableways for building sewers is rapidly in- creasing, as is also the use of portable derricks. With both ma- chines good work can be done both in excavating the trench and in placing materials in the construction of the sewers. On this page we illustrate a combination cableway and derrick designed for spans up to 500 ft., that promises to find a great field of Fig. 12. Combination Cableway and Derrick. usefulness in not only building sewers but in many other classes of construction. The general plan is extremely simple. The derrick is built on a car with a hoisting engine and boiler. Over the A-frame for the derrick is erected a head tower for the cableway. A tail tower is erected at the other end of the work and the cableway strung and anchored to dead men as shown. In moving the cable- way, only the tail tower need be taken down. It is possible to use both the derrick and cableway at the same time, or work can be carried on with either. This arrangement means a saving in time in carrying on work. This design was gotten up by the New York Cableway & Engineering Co., 2 Rector St., New York. Life of Main Cable. A %-in. wire cable used on an incline on the Chicago Main Drainage Canal lasted from 100 to 160 days, during which time it made from 30,000 to 50,000 trips, carrying from 50,000 to 80,000 cu. yd. of solid rock. Assuming the rock to weigh 4,300 Ib. per cu. yd. the life of the cable was from 108,000 to 172,000 tons. A Telpher System. Engineering and Contracting, Oct. 18, 1916, describes a method of disposing of subway excavation in New York City, by telpherage. COST WITH CABLEWAYS AND CONVEYORS 587 The power for hoisting and trolleying was furnished by a 60-hp. 250-volt direct current motor. A Lidgerwood 2-drum hoist was used for hoisting and trolleying. The car was a home- made affair, composed of four standard cast iron wheels 8-in. in diameter, which run on two 18-in. I-beams. These wheels sup- ported two standard cast iron sheaves, 16-in. in diameter, through which the hoisting cable ran. The cables were arranged as shown in Fig. 13. Steel buckets and skips were used for handling ma- terial, the former holding about 1 yd., the latter 2 yd. of ma- terial. ' /' "Cable Trolle ,/ 'Cable Hoist Hoist Drums E.&C. Fig. 13. Arrangement of Cables for Telpher System. A Skip Dumping Device. This was developed in connection with the Ashokan Reservoir work of the Catskill Aqueduct and is described in Engineering and Contracting, Nov. 1), 1910. The cableway used was of the Lidgerwood type and was equipped with Locher skip dumping mechanism. As shown in Fig. 14 the dump line and the hoisting rope are wound on the same drum C in the cableway tower and all their motions coincide. The dump rope, at the tower, runs down through a fall block A, then up over the sheave B, and thence to the main drum C. By pulling down the fall block A, which is suspended in the loop of the dump line, this line is shortened, lifts the rear of the skip and thus dumps it. It is the method of pulling down this fall block with which is novel. The old method was by a cable which wound upon a small drum. This method worked well, but was slow. The new method consists in pulling down the fall block by means of a cable which is fas- tened to the block and passes from there through a stationary sheave D directly below, thence through a sheave E fastened to the end of a piston rod, operated by a compressed air cylinder about 12 x 72 in. in size and thence back to a stationary anchorage F on one of the heavy timbers of the tower. By passing the cafile through the sheave E on the end of the piston the distance through which the piston acts is only one-half the distance through which 588 HANDBOOK OF EARTH EXCAVATION the fall block is moved. The piston is operated by compressed air which is used for operating all the machines in the work. Drag Line Cableway Excavators. These machines consist of a bucket carried on an over-head or track cable and a drag or load line. The machine is operated and controlled, as a rule, by a double-drum hoisting engine. One end of the track cable is se- curely fastened to a suitable anchorage, and the other end is supported by a tower, in the case of a slack or gravity cableway. Fig. 14. Skip Dumping Device for Cableways. The track cable can be pulled taut or slackened by means of a set of buck lines, leading to a drum on the engine. The drag line leads from the bucket over a sheave on the tower to the buck drum on the engine. In operation, the bucket is lowered into the excavation by slacking the cables, and is then drawn forward until tilled. While the bucket is loading, the track cable remains flat. As soon as the bucket is loaded, the operator gradually tightens the cable and at the same time hauls in the load by the drag line, so that the bucket is lifted and pulled to the dumping point simultan- eously. The empty bucket returns to the loading point by gravity, the operators simply release the friction of the load-line drum. The foregoing explanation applies to a flat cableway, in which COST WITH CABLEWAYS AND CONVEYORS 589 the empty bucket is lowered by gravity. In some installations it is desirable to have the loaded buckets operated by gravity. The capacity of a cableway excavator depends on many factors, among which may be included the working span and depth, the available power, the nature of the material, and whether it is dry or wet, as well as the efficiency of the labor. Mr. W. H. Wilmn, in Engineering Record, June 5, 1915, states that a 1-yd. machine, working either wet or dry gravel, on an average span of 500 ft., and to a depth of about 35 ft., has easily averaged 35 cu. yd. of material per hour excavated, and carried to the top of a plant 60 ft. high. A 1^-yd. machine, operated by a 10 x 12-in. engine, under similar conditions, has averaged 50 cu. yd. per hr. Under ordinary working conditions, taking into consideration all the delays, a 1-yd. machine should average from 200 to 250 cu. yd., and a 1^-yd. machine 350 to 400 cu. yd. per day. Under favorable conditions, and on usual spans of 400 and 500 ft., a load line should have a life of about 20,000 cu. yd., and a tension line should give greater service, averaging about 25,000 cu. yd. The track cable should average about 50,000 cu. yd. Figs. 15 and 16 shows various arrangements of cableway ex- cavators made by J. C. Buckbee and Co., Chicago, 111. A Cableway Scraper Excavator. Engineering and Contracting gives the following in the issue of Apr. 23, 1913. A new modification in cableway scraper excavators is illustrated by the accompanying sketches. This excavator will work under water as well as in dry pits and has been quite widely employed in stripping, in gravel pits and in other loose soil excavation. The records given later indicate its economy of operation. In general the plant consists of a track-cable on which runs a carriage operated by a hauling rope and carrying suspended a scraper bucket. The track cable has an adjustable attachment at one end to a mast and is at the other end fastened by a bridle hitch to two anchors. By means of this adjustable mast con- nection, the track cable can be slacked to lower the bucket into the pit to dig, and then made taut to raise the loaded bucket out of the pit and provide a track cableway for hauling the load to the pit bank to be discharged. The line pf he track cable, being from the mast top on one side to the bridle hitch at ground level on the other side of the pit, is inclined, so that the bucket returns by gravity when the hauling rope is slacked. In brief, then, the operation is as follows: The bucket being at the pit side farthest from the mast, the track cable is slacked to lower the bucket to the pit bottom. A pull on the hauling rope draws the bucket ahead and it scrapes up a load. The track cable is then hoisted taut and raises the bucket out of the pit. The loaded 590 HANDBOOK OF EARTH EXCAVATION t*J| *i Hsbiui COST WITH CABLEWAYS AND CONVEYORS 501 502 HANDBOOK OF EARTH EXCAVATION bucket is then hauled up the track cable to the dumping point where it is dumped automatically. The bucket then returns by gravity to its first position of readiness to excavate another load. From this general statement it will be seen that the essential Shorfunk ~. C/io/n Bridle Cable Thimble 5/ieove Bridie Frame Fig. 17. Bridle Hitch for Tail of Track Cable. Cableway Scraper Excavator. , Tension Block - Tension Coble Tension Block Track Cable Fig. 18. Mast Top and Sheave Assembly Cableway Scraper . Excavator. structural and operating parts of the excavator are the adjustable attachments at the mast head, the bridle hitch at the opposite end of the track cable and the bucket and carriage and their op- erating lines. The bridle hitch is simple and is completely ex- plained by Fig. 17. Fig. 18 shows the mast head attachment COST WITH CA13LEWAVS AND CONVEYORS 593 which is explained as follows: From the rear drum of a double drum hoist at the mast bottom a tension line runs to the mast top and is fastened to the track cable block A, Fig. 18, after being rove as shown through blocks B and C. Block C is fastened in a fixed vertical position to a collar ring which is free to revolve around the mast, but the other blocks have ordinary swivel connections. The tension line, as its name indicates, is employed to make the track cable alternately slack and taut. Tt ruing now to the bucket hauling and dumping operations, it is noted, first, that from the front drum of the engine a line runs Fig. 19. Carriage and Bucket and Operating Attachments Cableway Scraper Excavator. to block D on the mast, Fig. 18, and thence to the dump block to which the bucket pull chain is attached as shown by Fig. 19. This line, called the load cable, hauls the bucket on its carriage along the track cable. Fig. 19 shows the bucket and carriage and their various cable and chain attachments. The purpose of all these parts is clear from the drawing except possibly that of the dump chain. In traveling along the track cable the carriage and the traveler block keep in the relative positions shown until the dumping point is approached. Then the traveler block is ar- rested by a stop on the track cable, but the carriage and bucket continue on until a loop is taken up in the dump chain sufficient 594 HANDBOOK OF EARTH EXCAVATION to elevate the rear end of the bucket and dump the load. The relative adjustment of the bridle and push chains determines the digging angle of the bucket. A number of this type of cableway scraper excavators are in use. The following figures are furnished of the cost of operation of one plant which is installed at a gravel pit: Engineman $3.00 Fireman 2.00 \>/z tons coal 3.50 Oil. waste, etc 0.50 Total $9.00 This cost is for a 10-hr, day. A 1-cu. yd. bucket is used and about 300 cu. yd. per day are handled. On this basis the cost is 3 ct. per cu. yd., not including overhead expenses, shifting, etc. The machine is known as the Shearer & Mayer Patented Dragline Cableway Excavator. It is sold by Sauerman Bros., Chicago, 111. The Cost of a Tower Scraper Excavator. Engineering and Contracting, Oct. 26, 1910, gives the following: This cableway rig was used to operate a 48-cu. ft. bucket on the New York State Barge Canal construction. The greater part of the cost of this plant is in the hoisting engine and scraper bucket, both of which would have considerable salvage value. The total cost of the plant was: ft, B. M. lumber at $38 per M $ 193.04 360 ft. B. M. white oak at $45 per M 16.20 540 Ib. iron bolts and nuts at 6 ct 32.40 120ft. %-in. wire rope backstays 13.20 2 %-in. turnbiickles ' .80 1 headblack sheave and bearing 10.00 1 hauling sheave and bearing 4.00 18*4x10' Lidgerwood double drum hoisting engine 1,089.00 1 scraper bucket, complete with 'cutting edge, sheaves, etc 300.00 Labor erecting based on condition in Northern New York, carpen- ters at $?.50 per 8-hr, day '200.00 Total $1,858.64 The following is an estimate of the operating cost of the plant, also furnished by the Atlantic, Gulf & Pacific Co.: . Wire rope $160.00 20 tons coal at $4 80.00 Oil, waste and repairs 15.00 Total per month $255.00 To this is to be added the labor cost. Each shift requires the following force: COST WITH CABLEWAYS AND CONVEYORS 595 1 foreman at 37% ct. per hr : $ 3.00 1 engineman at 37% ct. per hr 3.00 1 fireman at 22 ct. per hr. l.<6 1 signal man at 25 ct. per hr 2.00 5 laborers at 20 ct. per hr - 8.00 And an additional 4 laborers at 20 ct. per hr 6-40 Total lator per day " $24.16 Fig. 20. Operation of Field Tower Excavator. Assuming 26 working days and two shifts per day, the labor cost for one month is $1,256.32 which, added to $255 given above, makes a total cost for operation of $1,511.32. Assuming interest on plant at %% per month we have an additional $9.30, making the grand total $1,520.02. Costs with a Scraper Bucket Cableway. Detailed description and illustrations are given in Engineering Record, Dec. 22, 1894, of a cableway handling a scraper-bucket at Niagara Falls, Ontario. The plant consisted of an overhead Lidgerwood cableway sys- tem carried on towers operated by a simple do Jble-drum 8 x 10-in. engine and a boiler, and carrying a scraper-bucket for digging, lifting, carrying, and loading sand. The operating expense per day, with an output of 400 cu. yd., was as follows: Per day 1 engineman $2.50 1 fireman 1.50 1 bucket-man 1.75 1 breaking down man 1.50 1 foreman 2.50 % ton of 'coal (swept from cars) 0.00 Total operating expense $9.75 506 HANDBOOK OF EARTH EXCAVATION Cableway Operation in Cecila Slough. Through the courtesy of Lt. W. H. Bixby Corps of Engineers U. S. Army, I am en- i i *--: j Ar3pr t- Fig. 21. Details of Tower for Field Tower Excavator. abled to publish the following report, submitted to him by Joseph Wright, on the operation of a cableway in Cecila Slough, 111., from Oct. 10 to Dec. 20, 1904. COST WITH CABLEWAYS AND CONVEYORS 597 This period was chosen because it is thought to be more nearly representative of what might be expected of such a plant working in soft material under normal conditions, provided that allowance be made for extraordinary breakages and renewals men- tioned below: Span of cableway 625 ft. Average length of haul 200 ft. Distance advanced each day by cableway about 70 ft. Material excavated Peat Capacity of dippers used, l 1 /^ cu. yd Nominal Actual average dipper load, 1-77/100 cu. yd. place measure. Total operating cost, Oct. 10 to Dec. 20 $11,546 Total yardage 131,414 cu. yd. Operating cost per yd 8.78 ct. The operating cost consists of Total cost of labor $7,261 Repairs, renewals, lubricating oil, kerosene oil for Wells lights, \vaste, etc $3,528 Coal $757 The above figures were taken from my books. It will be noticed that the item for repairs, oil, etc., is quite large. The item in- cludes $1,350 worth of new cables, whereas only about one-third of it should be properly charged to the operating cost for this period. The kerosene oil bill for lights was about $293, or about $126 per month. This, of course, is a proper charge if operated 24 hr. per day as was the case. Running over the journals and cutting out such items as should not have been charged to operating cost during this period, but which should have been carried as unexpended to a later period, I find an aggregate of $1,793, which should be properly deducted from the " repair " item above. Making this deduction reduced the " total operating cost " to $9,753, and the " operating cost per yard " to 7.42 ct. It is only fair to state in this connection that during the period of operating for which cost data are submitted, the towers were moving over very soft ground. This made the track work expensive, and was the cause of a number of extraordinary break- ages. Then, too, 3 crank shafts of the cableway engines were broken and renewed during this period, due to the engines having been provided with unsuitable foundations when installed. The cost of the new shafts has been included in *the deduction made above, but the cost of the delay occasioned has not. The engines were taken up and re-bedded during the winter of 1904 and 1905, and since have given no trouble by breaking shafts or heating of journals. Numerous other improvements, renewals, etc., were made at the same time, among which was the substitution of 2-in. patent locked main cables for the old 2^4-in. cables. This change alone 598 HANDBOOK OF EAUTH EXCAVATION resulted in the saving of $180 per month on carriage sheaves dur- ing the season of 1905 as compared with the period chosen. The number of buckets handled each day was registered by the bell boys. The cost given includes the cost of a large force of ditchers employed during the entire year, and the extra expense entailed by the necessity of having to move across the slough four times instead of once. The material was so unstable it was necessary partially to excavate the cut in passing over it the first time, ditch it, let it dry, and then pass over it again, repeating the process until the cut was excavated to grade. Then there was the cost of lengthening the span from 525 ft. to 625 ft. and many other things, which, while properly charged in our records, it is unfair to charge to the cableway when compared with other ex- cavating machines. During the period for which data are submitted in this re- port, the cableway was passing through the slough the first time and the cut was being excavated from 8 to 10 ft. deep. The rate of track laying was about 70 ft. per day. Had the cut been deeper the output would, of course, have been somewhat larger, and the labor account on track work materially smaller. The operating force required, and the wages paid were as follows : 1 engineman $125. per mo. who had charge of the machinery, and who slept on the ground, took his turn at the operating levers for eight hours each day, and who was subject to call at any time in case of a breakdown. 5 enginemen (S-hr. day) $ 4.00 per day 6 firemen (2 for each shift) 2.50 3 riggers (1 for each shift) 2.00 3 pumpmen (1 for each shift) 1.60 2 light tenders (1 for each night shift) 1.60 6 signal men (2 for each shift) ..-. 45.00 1 foreman (day shift only) 75.00 12 to 16 laborers (day shift only) 1.60 2 and sometimes 3 teams (day shift only) 3.50 day The above list constituted the operating force, but in addition a part of the salaries of Junior engineer ($130), Surveyman ($60), Timekeeper ($60), Locomotive engineer ($90) and Fire- man ($60), Blacksmith ($2.50) and locomotive rental were ap- portioned to the work. Nothing was allowed for interest and depreciation, but the plant Conveyor " A " 30 m.x925 in. conveyor $8,022.00 36 in. x 110 in. conveyor 1,497.00 Automatic feeders 1,243.00 Total $12,043.73 Labor and superintendence erecting supports, bins, etc. $ 5,067.41 Materials, lumber 3,732.12 Materials, miscellaneous Supplies and miscellaneous 1,072.59 Labor, installing machinery, etc 1,878.20 Overhead charges 2,369.09 Total for Conveyor " A " $26,372.76 ,-iiii:ii'v : in a; l-xr&T% To Tin Results of operation were as follows: Cost per cu. yd. Operation of Conveyor " A " Total of earth Labor conveyor operation $ 9,857.27 $0.016 Supplies miscellaneous 718.96 0.001 Power plant operation 3,200.54 Repair, plant operation 1,269.87 Depreciation 23,062.88 Tota l $38,109.52 $0.062 The main conveyor was driven by 100-hp. motor installed mid- way of its length. The feeders and cross conveyor were driven by a 20-hp. motor. COST WITH CABLEWAYS AND CONVEYORS 613 Electric current was generated at the site of the work by utilizing the drop of the main canal, and the total cost of production was about 1 ct. per kilowatt hour. Common labor was paid 30 ct. per hr. and mechanics ranged from $3 to $5 per day. Work was carried on in one 8-hr, shift daily extending over two years with intermissions of a few weeks during the coldest weather. The conclusion is that the work was done at least as cheaply and probably at less cost than with the borrow pit tracks ex- tending out over the dam on high trestles. Certainly the reg- ularity and uniformity of distributing the material together with the perfection of mixing the materials in the desired proportions were far better achieved than would have been possible by dump- ing cars from any considerable elevation. The reliability and freedom from all mishaps with the belt conveyor were most sat- isfactory. The capacity was abundant and the output was lim- ited only by the ability of the borrow pit crew to feed the belt at one end and the ability of the distribution force to place the material in the dam at the other end. Sometimes one and sometimes the other of these considerations governed the rate of progress which was never limited by the conveyor. A Bucket Elevator Plant. Engineering and Contracting, June 10, 1908, gives the following: The bucket elevator was 110 ft. long between centers, and had a 5-ft. " lap-over " at the top so as to discharge the material into the center of a bin. The elevator was operated at a speed of 250 ft. per min., with buckets spaced 20 in. apart. The material was discharged from dump cars into a " boot " at the foot of the elevator. Each bucket had a capacity of 15 lb., and, at the rate of 150 buckets per min., the capacity was 60 cu. yd. per hr. The speed of 250 ft. per min. was noteworthy, and was due to the special design of the link chain. This particular plant was one installed for removing the exca- vated material from the North River Tunnel, built by the Hudson River Railroad Co. The installation is one of several made for the same company by the Link Chain Belt Co. of New York City. Bucket Conveyor for Backfilling Retaining Wall. W. F. Schaphorst in Engineering and Contracting, Aug. 16, 1916, gives the following: A large river wall was very recently completed in Cedar Rapids, Iowa. This wall was of concrete and was 26 ft. high and designed to protect abutting property from the seasonal floods of the Red Cedar River. When the footings were built the mud excavated from the site was piled in front, forming an earth cofferdam. G14 HANDBOOK OF EARTH EXCAVATION After the wall had been completed this same mud was used as backfill. The problem of moving the mud from in front of the wall to its desired position behind it was solved by the construction of a novel and effective ladder conveyor. The buckets of this con- veyor were wide strips of metal which slid up a plank at an angle of about 60 with the plank and emptied as they passed over the sprocket at the top. A gang of men at the bottom shov- eled the mud into the buckets. Bibliography. " Handbook of Construction Plant," by Richard T. Dana. " Cost Data," Halbert P. Gillette. " Mechanical and Electrical Cost Data," Gillette and Dana. " The Britts Landing Quarry," R. D. Seymour, Jour. W. Soc. C. E., Vol. 2, p. 286. " The Bates Belt Conveyor on the Chicago Canal," E. B. Shana-ble, Jr., Jour. Assoc. Eng. Soc., Vol. 14, p. 469. " Cableways," Spencer Miller, Trans. Am. Hoc. C. E., Vol. 31, p. 377. " The Capacity, Power Consumption and Other Details of Belt Conveyors for Handling Materials," George F. Zimmer, Cassiers Magazine, August, 1909. " Methods of Excavating Foundations and of Handling Materials by Cableway in Constructing a Rein- forced Concrete Arch Bridge," Eng. and Con., June 30, 1909. " Characteristics of Wire Rope Tramways with Some Figures on Cost of Operation," W. S. Gemmert, Eng. and Con., April 29, 1908. miff !.<] \.r; ir.L ',o 5'i'H]-- y -'; .: ]. :!!; CHAPTER XIV METHODS AND COST WITH DRAGLINE SCRAPERS Dragline or Power Scrapers. These are scraper buckets pulled by a cable. If the scraper is bottomless it is not raised from the ground when loaded. Dragline scraper buckets having bot- toms are so rigged that they can be hoisted after they are filled. Bottomless Power Scrapers. These range in size from % to 7 cu. yd. capacity. The sizes, weights, and prices of the Sauerman power scraper are given in Table I. TABLE I. SAUERMAN POWER SCRAPER Approx ; mate Capacities Dimensions Weights prices prior cu. yd. ft. Ib. to 1916 % 3.25 x 3.5 x 1.3 1,600 $250 % 4.5 x 3.5 x 1.5 1,900 300 1 4.5 x 3.5x2 2,300 350 1% 5.5 x4 x2.3 3,000 425 2 5.5 x 4.5x2.3 3,500 600 These machines consist of two heavy side plates and a back plate, with a renewable cutter edge fastened on a runner frame pivotally and adjustably connected to the back plate. When the scraper is pulled forward the runner frame and cutter edge are tilted to the digging position. When the empty scraper is pulled back this runner edge and cutter frame is pulled flat, thus forming a sled for the scraper. The load is not dumped but is left at the point where the scraper starts back. This is a desir- able feature in sticky material. These machines require a 35 to 80-hp. engine, % to 1-in. haul back lines and 1 to l^-in. pull lines. Early Power Scrapers. First on the Chicago Canal and later on the Massena Canal (Engineering News, Aug. 15, 1805, and Dec. 15, 1898), a power drag scraper was used. The scraper held 3 cu. yd. of loose earth when not heaped and had a cutting edge 7 ft. wide. Fig. 1. Power Scraper on the Chicago Drainage Canal. It was operated by cables (Fig. 1) running to a 12}4xl5-in. engine. The towers at Massena were mounted on trucks and were 720 ft. apart. Cable A was used to dump the scraper. The scraper worked there in soft clay, cutting a deep swath; then it was moved over to cut another swath leaving a ridge of earth between the two for the purpose of guiding the scraper. Its 615 616 HANDBOOK OF EARTH EXCAVATION output in this soft clay was said to be 800 cu. yd. per 10-hr, day, but the actual records on the Chicago Canal showed only 250 cu. yd. daily output. Mr. Charles Vivian was the designer and contractor in both cases. The scraper did not work satisfactorily in hard material, nor in very wet material, nor in fro/en material. On the Erie Canal deepening (1897) small power operated scrapers were used on one contract to drag muck and earth over to a steam shovel which loaded it into cars. The engine was mounted on trucks. A horizontal wooden boom 50 ft. long, with a sheave for the tail rope at the end of the boom, was fastened to the engine truck platform. One or two men attended to -400' Sketch Showing Method of Stripping. Fig. 2. Layout of Plant for Stripping Overburden with Bottom- less Bucket. loading and dumping the drag scraper which they could readily do as it was small. The hoisting engine thus merely pulled the scraper back and forth. On the Suwanee Canal (Engineering News, Feb. 20, 1896), a power-driven bucket-scraper was used, the Trenton Iron Co., Tren- ton, N. J., being the manufacturers. Instead of towers, two masts provided with guy lines were used. After the bucket- scraper was loaded by a cable from the engine, another cable lifted it, and it traveled on a trolley conveyor to the dump, very much as buckets travel in the Carson-Lidgerwood cable trench machine. It is said that 200 cu. yd. of earth were moved daily for 6 ct. per cu. yd. with this device. Overburden Stripping with Bottomless Bucket. At the plant of the Diamond Sand and Gravel Co. at Bedford, O., a 1-cu. yd. Sauerman bottomless scraper, operated by a 60-hp. electric hoist, was used to remove the overburden from a deposit of gravel, the METHODS AND COST WITH DRAGLINE SCRAPERS 617 material removed being deposited in a ravine on one side of the gravel deposit. The hoist is a type specially designed for scra'per work, the rear drum operating the " pull-back " cable having a speed three times as great as the front drum. The machine re- quires one operator and a rigger stationed at the guide blocks to make the necessary shifts in the line of operation. This outfit installed represents an investment of about $5,000. The top soil of the hill is largely clay and runs from nothing to 6 ft. in depth. Hard " shoulders " of clay, when encountered, are removed by " sawing " the scraper back and forth over the obstruction. A day's output will fluctuate between 200 and 300 yd., depending on the nature of the material. Cost with a Bagley Scraper on Road Construction. In En- gineering News, Dec. 17, 1914, F. W. Harris gives data on the use of the Bagley power scraper on mountain road construction. He states that it is a most successful machine when used in connection with a logging donkey engine. The right of way is first cleared of logs, etc., by the donkey engine operating a cable. The scraper is then attached to the same line. With plenty of fuel and water and a short haul not exceeding 400 ft., a scraper should remove at least 400 cu. yd. of earth per day. In light earth and gravel cuts with a 200-ft. haul a 2.5-cu. yd. scraper will push another 0.5 cu. yd. of material ahead, and should easily move 1,000 cu. yd. in 10 hr. These scrapers are unsuccessful, however, in mucking out blasted rock. They will handle all kinds of loose earth, gravel, and boulders from 1 cu. ft. to 0.5 cu. yd., but the material must be loose. Wherever the iill is of considerable q antity, the haul short, and the material sandy or gravel, scraper work should cost about 7 ct. per cu. yd. On general road work, where time is lost in moving up, splicing lines, removing large boulders, etc., the average cost will run from 15 to 20 ct. per cu. yd., to which must be added from 3 to 5 ct. per cu. yd. for finishing as the scraper leaves the Work in a rough shape. On certain work two scrapers were in use, each having a capa- city of 2.5 cu. yd. One donkey engine was 11 by 13 in. in size, and the other 101/4 by 10% in. The wire cables had the following dimensions: main line 1% in. and haul-back line ~/ 8 in. The 10-hr, daily cost of a road gang was as follows : Foreman $ 6.00 Engineman 3.50 Fireman ; 2.75 Hook tender 4.50 Pumpman 3.00 Two rigging men @ $3 6.00 Total labor on scraper $25.75 618 HANDBOOK OP EARTH EXCAVATION One team hauling fuel or two men cutting on right of way... $ 6 00 Fuel 10.00 Use of donkey engine including depreciation, cable costs, etc. 10.00 Two teams and teamsters for finishing @ $6 12.00 Four laborers, finishing @ $2.50 ' 10.00 Total daily cost $73.75 Assuming 400 cu. yd. for an average day's work, the cost will be $0.185 per cu. yd. A Power Scraper for Handling Mud. Engineering and Con- tracting, Sept. 11, 1910, gives the following: In excavating the Long Island open cut and tunnel approaches to the new Penn- sylvania R. R. East River tunnels a considerable portion of the overlying swamp mud unsuitable for embankment was wasted over an adjacent area of swamp land. As this swamp area was a" to sheave at dea Jinan First Position "a ' to sheave at deadaan Rope "It" to Jiuifl on e Second Position Fig. 3. Rigging for Scraper Bucket. of such a character that spoil car tracks could not be laid or maintained on it, use was made of drag line scrapers to dis- tribute the spoil. On one side of the swamp area two travelers were mounted so as to run back and forth along the edge of the swamp. A double drum hoisting engine mounted on each traveler operated a scraper rigged as in Fig. 3. Referring to the drawing, the scraper was pulled forward by the rope a which passed through a sheave attached to a deadman on the opposite side of the swamp from the traveler, while the rope 6 was allowed METHODS AND COST WITH DRAGLINE SCRAPERS 619 to run loose as shown by the upper sketch of the drawing until it was desired to dump the scraper. Thj^ was accomplished by clamping the lower drum operating rope a, and pulling the rope 6 until the scraper was in the position shown in the lower portion of the drawing when a slight pull on the rope a with rope 6 slacked a corresponding amount completed the turn. The scraper was pulled back to the starting point by the rope 6. A Bottomless Scraper for Loose Material. Engineering and Contracting, May 15, 1912, gives the following: Fig. 4 is a type much used in the Joplin, Missouri, mining district for loading mine tailings into cars. It should prove useful for handling Fig. 4. Bottomless Drag Scraper for Loose Materials. loose material of other kinds. This scraper has no bottom and thus handles the material by pushing it ahead of it. It is oper- ated by means of tail and head ropes from a two drum engine. The scraper illustrated is 5 ft. 2 in. long 3X ft. wide in front and 4 in. wider at the rear, and is 14 in. deep. A Power Scraper and Wagon Loader. Engineering and Con- tracting, Dec. 9, 1914, gives the following: The machine con- sists of an inclined runway mounted on a truck, together with a drag scraper. The scraper is hauled back into the excava- tion 100 to 500 ft. for its load, which it carries up the runway of the incline and dumps automatically into a hopper at the top to be loaded into wagons. The scraper is dragged by a continuous drag line running over a pulley at the top of the machine and another pulley anchored at any convenient point in the excava- tion. Power is supplied by ,a gasoline engine, or an electric motor. The hopper from which the wagons are loaded has a capa- city of 1^ cu. yd. and the gate, placed 6 ft. above the ground, may be operated by the engineman. A 125-gal. water tank is mounted 620 HANDBOOK OF EARTH EXCAVATION on the truck. The front wheels under the machine are in pairs, permitting easy rotation of the apparatus to load from any position of the excavation. The outfit is manufactured in three sizes of 6, 10 and 20 cu. ft. scraper capacity and has a rated output at 100-ft. haul of 15, 25 and 40 cu. yd. per hr. for each size, respectively. The maxi- mum heights vary from 14 ft. to 16 ft.; length from 20 ft. to 22 ft.; widths from 5} ft. to 8 ft.; and shipping weights from 7,000 Ib. to 12,100 Ib. Engines vary from 10 to 25 hp. Scraper speed may be varied from 150 to 350 ft. per min. Under ordi- nary conditions a cost of 4 ct. per cu. yd. for excavating and loading is claimed for their machines. The apparatus is manufactured and sold by the Insley Mfg. Co., Indianapolis, Ind. Fig. 5. Power Scraper and Wagon Loader. Portable Derrick Excavator. Engineering and Contracting, Oct. 14, 1914, gives the following: This excavator (Fig. 6) will handle -a %-cu. yd. bucket on a 20 to 22-ft. boom with a range of hoist up to 12 ft. Except the boom, which is wood, the con- struction is steel and steel outriggers are provided. Where con- ditions do not permit the use of outriggers, guy ropes can be substituted. The machine is transported by team and pole, neck- yoke and single and double trees -are provided. The engine is vertical, double cylinder and geared giving a rope pull of 4,200 Ib. at a speed of 100 ft. per min. All other parts including wire rope, blocks and fittings are the manufacturers' standard except the digging bucket which may be any make preferred by the purchaser. The machine has a digging capacity of 20 cu. yd. per hr. and in actual work has shown much higher records. The METHODS AND COST WITH DRAGLINE SCRAPERS 621 022 HANDBOOK OF EARTH EXCAVATION cost of the machine is under $2,000. It is made by the John F. Byers Machine Co., of Ravenna, Ohio. A similar machine made by the Economy Excavator Co., Iowa Falls, Iowa, is shown in Fig. 6. Cableway Scraper for Sidehill Work. Engineering and Con- tracting, Oct. 9, 1907, gives the following: The arrangement illustrated in Fig. 7 was used in removing part of a hill face that caused a skew pressure on a tunnel being constructed through a hillside. As shown, the device consisted of a timber tower, about 50 ft. high, to which was attached a suspension cable of 1^-in. wire rope, secured at the uphill end to a movable holdfast, which allowed swinging the cable laterally with the Fig. 7. Cableway Scraper for Sidehill Work. tower as the center. A boiler plate scraper pan, 6 ft. wide, was suspended from a traveling block on the cable. Up and down haul lines were attached to the scraper by a bridle arrangement, and led to the drums of a hoisting engine placed at the foot of the tower. The suspension cable was also led to one drum of the hoist by suitable blocks. This allowed the cable with travel- ing block and scraper to be raised or lowered by winding on or off the drum; and consequently the feed of the scraper was under control as it descended the hill. The material was a gravel face, the work being done during the winter months, with temperature far below zero, and the hill face deeply frozen. Before the scraping was begun a V-shaped gulley for the scraper to run in was made by blasting out stumps and frozen earth, after which the sides were picked down to furnish loose material to the scraper. At the tower the scraper emptied into a plank chute 6 ft. wide, with sides 1 ft. high. The chute was placed at an inclination 1^ to 1, which was enough, METHODS AND COST WITH DRAGLINE SCRAPERS f>23 except when the gravel was wet from snow or rain, and then the fine sand clogged and had to be removed with pick and shovel. When the earth piled up at the mouth of the chute, a new chute higher up or slightly to one side, was constructed. Beside filling itself, the scraper would often push down a large mass of gravel, thus sometimes carrying down from 4 to 6 cu. yd. per trip. The gravel wore out the bottom planking of the chute, two sets of 3-in. plank being used up. About 30,000 cu. yd. were excavated at a cost of 30 ct. per cu. yd., this cost including running hoist, rigging scraper and material and labor in building the chute. Leveling- Ground with Power Scraper. James C. Bennett, in Engineering and Contracting, Dec. 4, 1912, gives the following: Gold dredging has in years past left considerable areas of ground within the city limits of Oroville, Cal., in an unsightly condition. More recently the city has demanded in new work that the dredges restore the " worked " ground to a surface approximat- ing the original. At the outset of the work of restoration, at- tempts were made to use horse-drawn scrapers. Owing to the character of the material, however, the costs proved prohibitive, and a more economical method was sought. The " boats," as they are called locally, deposit the gravel, sand, and clay in irregular piles varying in height from 8 or 10 to 25 and 30 ft. above the original surface level. The deposited gravel contains rocks ranging in size from sand to 20 or 24 in. in diameter, and in some places, a considerable quantity of clay and sand. This makes a material that is very difficult to handle economically, as it is hard to fill a scraper to anything like its capacity. In using horses, the work was found to be very severe on the stock, and a team was rendered unfit for service after a very short time. The equipment that is described was developed by one of the dredging companies, and has been used in leveling an extensive area. Until a short time ago, however, it was* never used where there was any necessity for working to grade, so that little or nothing was known of the cost per cu. yd. of material handled. Consequently, when the writer attempted recently to learn what should be a reasonable price at which to contract for a job of making a fill for a street grade, filling a large water hole to a grade above that of standing water, and raising a part of the ground to a grade suitable for building lots, the only data that could be obtained were some records of costs per acre ranging from $175 to $200. As has been pointed out, these gave no con- sideration to the yardage involved, so that the information was of little value. Finally, the contractors and the writer agreed on a lump sum 624 HANDBOOK OF EARTH EXCAVATION for the job, based on an estimate of the time required to do the work. Sufficient record of previous work was. -available to afford reliable information as to the daily expense of such \\wrk, so that such an estimate was mutually looked upon as the most satisfactory. The estimated time for the completion of the job was 75 days, which should cover repairs, setting deadmen, mov- ing lines and blocks, and moving the machine from one position to another. The elapsed time between start and finish of the work was 82 working days. Of this, G2 days were occupied in actual scraping, 10 days in moving lines and winch, and making repairs, and there were 10 working days in which no work was done for reasons not attributable to the work in question. The time devoted to actual scraping during the 62 days averaged 7 hr. per day. Close record was kept of the number of loads hauled, and, at intervals, the loads were measured. It is believed that 1^4 cu. yd. is very nearly a correct average load. The total number of yards moved, based on the number of trips hauled, was 15,300. The regular crew consisted of a winchman and two helpers. Had this work been done in conjunction with some other, it would have been unnecessary to retain both helpers continuously on the job, since but one is needed during the time that the scraping is in progress. His work is to watch at close range and direct, by signal, the loading of the scraper. The second helper is required principally in moving blocks and lines from one deadman to another. A little study of the job prior to starting the work of scraping materially lessened the lost time, since nearly all of the deadmen were set before the filling was begun. Thus it was only neces- sary to stop the work for such length of time as was required actually to move the lines from one block anchorage to another. During the execution of the work the winch itself was moved twice, that is, it occupied three positions including the one in which work was started. Throughout the greater part of the work the hauling line was run through one block only, while the back line ran through three most of the time. The costs of the job were as follows: :i-jj -jiHiili: .->.!' jn i; .r-jvf ' ,i:J;;m 1 winchman $ 5.00 2 helpers, at $2.50 5.00 1 horse (for moving lines, etc.) 1.00 133.33 kw. hr., at 2% ct 3.00 Total per day $ 14.00 Total Cost: 72 days, at $14 $1.008.00 Repairs (materials only, labor being included above) 35.00 METHODS AND COST- WITH DRAGLINE SCRAPERS 625 4-horse team, man arid scraper, resurfacing street grade, 1 day 10.00 600 ft. second hand, l^-in. hauling line 54.00 600 ft. second hand, %-in. back line 30.00 Depreciation at 10% 120.00 Total cost for the job $1,257.00 From the foregoing figures it will be seen that the unit cost for the job was 8.2 ct. per cu. yd. In the above statement of costs there are one or two items that involve a slightly heavier charge against the job than is strictly just. The depreciation charge is probably a little high, since, aside from the scraper itself, there is not a particularly heavy wear and tear on the equipment. The full cost of the ropes is included, although the same ropes would probably have served for the handling of an additional 2,000 or 3,000 cu. yd. of material. The second-hand ropes were secured from mines where they had been discarded as hoisting ropes in compliance with state mining laws which limit the service of such ropes to a com- paratively short time owing to the extent to which human life is dependent upon its reliability. At the conclusion of the work the following figures were derived: Average length of haul, ft 175 Average day's duty, cu. yd 247 Average hourly duty, cu. yd 35.2 Largest day's duty, cu. yd 425 A 50-hp. constant speed motor was belted to the first of two pinion shafts, and was kept running continuously while scraping was in progress, thus reducing the time of reversing the travel to a minimum. In the preparation for the job a temporary power line of 4,000 or 5,000 volts was run to the edge of the work, where the transformers were set on the ground. From the secondary side of the transformers a 440-volt current was carried to the motor by means of an armored three-conductor cable. This cable was a piece of discarded gold dredge equipment. By this arrangement, it was possible to move the winch with its own power from one part of the work to another, and still leave the transformers undisturbed. At first thought, the charge for electric power 2^4 ct. per kw. hr. seems high, but in view of the erection of the temporary pole line by the power company and delivering the current to the transformers at whatever point on the work the contractors selected, it will be found a very reasonable charge. The speeds of both hauling and back lines were approximately 130 ft. per min. This proved a very satisfactory speed for the hauling line, though in other material a rate of 150 ft. could HANDBOOK OF EARTH EXCAVATION undoubtedly be used to excellent advantage. For the back line the speed of 130 ft. was slow, and should have been increased to not less than 150 ft. per min., while it is quite possible that 175 ft. would have given good results. The scraper, 12 ft. long over all, was built of good, sound, 2-in. planks, secured to steel end plates, and the whole thoroughly strapped with }x3-in. bar steel. A bail iron was attached to each end plate, and carried on around the back as a reinforce- ment. At the outset some experimenting was required before the bail irons were set at the angle that gave the best results in filling the scraper. During the progress of the work, the angle 1 ^--Approximate Angle of Digging Pifth EnqbContg- Fig. 8. Wooden Scraper for Leveling Ground. was changed once or twice owing to varying conditions of ground and material. The back line was attached by means of short bail irons projecting to the rear of the scraper. Here again some experimenting was necessary before the irons were set at the angle that would unload the scraper to the best advantage. Dur- ing the greater part of the work it was only necessary to reverse the rope travel with a light jerk to discharge the load, as the rear bail irons were so set that the scraper was tipped fairly well forward so that it was easily withdrawn from under the load. On some of the work, however, there was so much wet and very sticky clay that quite a hard jerk was necessary to clear the scraper of its load. In this the operator soon became so skilled that very little time was lost on this account. Canal Work with a Power Scraper. This device was designed by James R. Hall, for work on the Swanee Canal, Ga., and is METHODS AND COST WITH DRAGLINE SCRAPERS 627 described in Engineering News, Feb. 20, 1896. It consisted of two guyed masts, supporting a 1%-in. carrier cable of 200 ft. span, on which a 2-wheeled carriage traveled. Power was sup- plied by a double-cylinder, three-drum hoisting engine. The scraper is a rectangular bucket with the lips fitted with cutting edges. The haul or load rope led directly from the bucket-bail through a sheave at the top of the head mast to a drum on the engine. The hoisting rope led from the bail of the bucket through a sheave on the cableway carriage to a second drum. This rope was also used to pull the carriage and bucket, back from the spoil bank. A third rope, the out-haul or pull-back rope, led from the bottom of the bucket through a sheave on the cable carriage, thence through a sheave on the tail mast, and back to the engine. The crew required consisted of an engineman, a fireman, a helper, and one signal and general utility man, besides two men who prepared anchorages, set masts, etc. The daily operating cost, including fuel and oil, was $12. The output was 250, to 300 cu. yd. per hr. day. The total unit operating cost was about 6 ct. Shifting required 1 to 1% hr., and out of 11 hr., 3 were consumed in moving, oiling, repairing, etc. Loading Wheelscrapers with an Engine. In Engineering News, June 23, 1904, G. H. Dunlop described the method used in exca- vating a canal in Australia. The cutting was in clay, and was 40 ft. wide, 42 ft. deep, with side slopes of 1 to 1. The material was excavated by wheelscrapers, holding 16 cu. ft., drawn by two horses. Instead of using a snatch team, an engine was placed on the bank and, by means of a %-in. cable, assisted in loading. This rope was attached and detached from the scraper poles by a laborer. A pony ridden by a boy dragged the rope from place to place as required. On another piece of work where the cut was shallow and the bottom width was 117 ft., the engine was placed in the bottom of the cut. The depth of cutting was regulated by a gage wheel under the rear end of the pole. In deep parts of the cut the pole was removed and replaced by a third wheel. The scraper was loaded by the engine, and then hauled out of the cut by a long rope attached to horses traveling on the bank. Power Scraper Work in Oregon. C. G. Newton, in Engineer- ing News, Oct. 20, 1904, gives the following: A power scraper was used to excavate gravel under several feet of water in the bed of the Grande Ronde River, Oregon. It dragged the ma- terial 200 ft. up an apron and dumped it on cars. A 30-yd. car was loaded in 16 min., and another car moved up to its place in 12 min. The cost was 7 to 8 ct. per cu. yd. 628 HANDBOOK OF EARTH EXCAVATION At Portland, Oregon, hard, stiff, blue clay, and a covering of 1 ft. of silt was excavated from Guild's Lake. The material was hauled from 400 to 700 ft. and dumped over a bulkhead 4.5 ft. high at the rate of 600 to 800 cu. yd. per day. The cost was 14 ct. per cu. yd. The cost of moving dirt, sand or gravel under average condi- tions with a 400-ft. haul, for street grading work, was as fol- lows per 10-hr, day: Donkey engine $2,250 4% yd. Hammond scraper 500 Lines 500 Blocks 150 Miscellaneous 300 Total plant $3,700 Interest, 8% on $3,700 -=- 270 days $ 0.81 Depreciation 9.20 1 engineman 3.00 1 foreman 3.50 1 fireman 2.50 1 ton coal 5.50 1 coal tender 2.50 Oil supplies 1.00 Repairs to lines, etc 2.50 Total per day, 405 cu. yd. at 7.35 ct $30.51 Power Scraper Work in Alaska. Engineering and Contracting, Feb. 26, 1908, gives the following: In the Klondike, steam scrapers are often used in handling tailings from the creek-min- ing operations. The ordinary power scraper outfit used in opera- tions on tailings consists of a scraper of from ^ to ^ cu. yd. capacity, operated by a double drum, 2-cylinder hoist, of 25 to 30 hp. This outfit handles on an average 250 cu. yd. of loose material in 24 hr. at an average cost of 49 ct. per cu. yd. In explanation of this high cost it may be stated that the wages of laborers are about $5 per day with board, or $8 without board; that bituminous coal at Nome costs $17 per short ton, and that spruce wood for fuel costs about $12 per cord. The scrapers drag the material from the pit to the dump, a horizontal distance of from 100 to 300 ft., and a vertical distance of 20 to 50 ft. The gang employed usually consists of three x to four men a fireman, a hoistman and either one or two men to fill, guide and dump the scraper. The form and rigging up of the scrapers and the system of sheaves and drawback usually employed are shown in Fig. 9. Toothed scrapers are not always used, but are preferred. An adaptation of one of these plants was used in stripping loam in excavating for a reservoir at Portland, Ore. In this case a bottomless scraper was used. The scraper had a theoretical METHODS AND COST WITH DRAGLINE SCRAPERS 629 capacity of 6 cu. yd., but actually handled about 3 yd. In the work in seven 10-hr, days, stripping to 4 ft. in depth, 400 cu. yd. per shift were handled by the outfit. Furrows 300 ft. long were made by the scraper. A 60-hp. boiler was used but only one cord of wood, at $2, was burned per day. A double drum hoist, provided with 10 x 12-in. cylinders and geared 6 to 1, was Fig. 9. Arrangement in Power Scraper Work. used. The gang consisted of a winchman, a fireman, and two scraper men, at $2.50 per day. Under these considerations the operations were said to cost about 5 ct. per cu. yd. Loading Scrapers by Power. Engineering and Contracting, Sept. 18, 1012, gives the following: In excavating for a small artificial lake for the site of a residence at Libertyville, 111., the contractors used four-wheel Maney scrapers and loaded them by power from a stationary engine. 630 HANDBOOK OF EARTH EXCAVATION The lake is about 400 ft. in diameter, and the material exca- vated consists of a very hard brick clay. At the start snatch teams were employed to aid in loading the scrapers, but they were replaced by a 10-hp. double-drum engine. The engine is located on the bank of the lake pit (Fig. 10) and a ^-in. steel cable is run from each drum to a double sheave block about 50 ft. from the engine and through this block to any point in the pit. A small hook on the end of the cable is attached to the tongue of the scraper and pulls it along over the plowed ground until it takes its load. Another team and scraper then follows and is loaded in the same way. This continues until the end of the pit is reached. The cable is then pulled back to the far end of the pit by the last scraper loaded, while the scraper is on its way to the dump. The two cables are operated by one man at the engine, and sometimes both cables are used at one time. The scraper consists of a scoop of 29 cu. ft. capacity, suspended on a four-wheel steel wagon frame. A record of the work done during the month of July, 1912, is given below. The length of the haul varied from 200 ft. to as much as 1,200 ft., the average being 400 or 500 ft. With 210 hr. of foreman time, 788 hr. common labor, and 1,794 hr. of team and driver, the output was 6,686 loads. These data give the following units of output : 6,686 loads at 29 cu. ft. equal, cu. yd 5,386 Average cu. yd. per team hr 3 Average cu. yd. per scraper hr 3.92 Average cu. yd. per scraper per day 35.3 Average cu. yd. per day '. 256.5 It will be noted that two teams are required for plowing on this work, and as many as four teams were used in very hard places. In the figures, however, the number of scrapers at work may be considered as two less than the number of teams. Figuring the foreman at $3 per day, the laborers at $2.25, the driver and team at $5, the cost of the work may be estimated as follows: Per day 1 foreman $3.00 1 dumpman , -. 2.25 2 pitmen 4.50 1 engineman 2.75 9 teams and men and 7 scrapers ....,..,.'.........,...... 45.00 Total labor per day $57.50 Cost of labor for 255 cu. yd. (output of 7 scrapers) per cu. yd ...... $0.226 It should be remembered that the material is hauled about 500 ft. on the average and that it was very hard to dig. When METHODS AND COST WITH DRAGLINE SCRAPERS 631 the top soil was removed, the contractor estimated that the cost was only about 10 ct. In the top soil work the digging was very easy and the haul was short. Stalls for Teams Engine .Room Fig. 10. Sketch Showing Manner of Loading Scrapers Using Hoisting Engine and Cable. Basement Excavation by Power Scraper. Engineering Record Aug. 8, 1914, gives the following: Excavating the basement fpr the new office building of the Occidental Realty Company, in Devotion i > -j'lruU; Hrti^iK' ^m-ym'-' Fig. 11. Arrangement of Cables and Plant for Scraper-Bucket Basement Excavation. the business center of Indianapolis, was carried out by using a power scraper which handled 12,000 cu. yd. of gravel in 18 days from an area of 70 x 200 ft. As installed the equipment consisted 632 HANDBOOK OF EARTH EXCAVATION of a Sauerman %-yd. scraper with pull and tail ropes, a three- drum, 75-lip. Thomas electric hoist, receiving hopper, two Link- Belt bucket elevators and two loading bins located as shown in the drawing. As operated in this excavation a head-and-tail block served as a guide for the tail cable leading from the rear drum of the hoist to the rear of the excavator. The .pull cable led from the front drum through a head guide block to the front of the bucket. Forty-two teams were employed to haul the material away. Labor and other expenses amounted approximately to $20 per day, the output being nearly 700 cu. yd. per day. Dragline Scrapers on Chicago Canal. On the Calumet-Sag channel of the Chicago drainage canal several drag-line machines were employed. On Sec. 2, in glacial drift during 1912, a Bucy- rus dragline machine, equipped with an 85-ft. boom and with 2.5-yd. Page and Bucyrus buckets, averaged about 50,000 cu. yd. per month, working one shift of 10 hr. The average force em- ployed was 10 men. On Sec. 4, a Marion self-propelling drag- line excavator, with a 100-ft. boom, and a 3.5-yd. bucket for glacial drift and a 6-yd. bucket for peat and light material, excavated an average of 60,000 cu. yd. per month, working two 10-hr, shifts daily. The average force employed was 12 men per shift. Armstrong Dragline in Montana. Engineering and Contract- ing, Sept. 2, 1908, gives the following: This machine consists of an upper platform rotated upon a lower frame. The frame is supported on skids and travels over rollers. A long boom and the power plant are carried on the upper platform. The scraper bucket of 1.5 cu. yd. capacity is pulled toward the machine. The machine travels under its own power away from the cut. These machines are made of wood or of steel. The machinery and iron work of the frame cost $4,500, and the lumber and erection labor about $1,000 more; a steel machine complete costs about $9,000. The working weight is 45 to 50 tons, and the maximum capa- city varies from 50 to 100 cu. yd. per hr. The cost of operating a machine of this type, with a 48 by 96-in. vertical boiler, an 8 by 12-in. hoisting engine, and a 5 by 8-in. swinging engine during October, 1908, on the Huntley Reclama- tion Project, Montana, is given in Table I. A 2.5-cu. yd. bucket was generally used. The cut was 16 to 19.5 ft. deep, 12 to 15 ft. consisting of well compacted sandy soil, and the remainder of coarse gravel and sand saturated with water. The work during the month was difficult, the machine handling about 70% of its normal output. Two 8-hr, shifts were worked. METHODS AND COST WITH DRAGLINE SCRAPERS 633 TABLE I. COST OF EXCAVATION WITH ARMSTRONG DRAGLINE EXCAVATOR Superintendent (a $125 $ 41.67 2 dipper men (a $130 171.17 2 dipper tenders (a $95 125.08 2 firemen (a $85 111.92 2 groundmen (fi $100 131.67 Team and driver hauling supplies @ $4 43.50 Laborers (a $2 21.75 Working Repair time time $ 6.26 30.33 22.17 19.83 23.34 2.50 1.25 Total labor cost, 16,000 cvi. yd. Labor cost per cu. yd $646.76 $4.04 $105.68 $0.67 Lost time $ 8.33 34.67 25.33 22.67 $117.67 $0.74 Total time $ 56.26 236.17 172.58 154.42 181.68 46.00 23.00 $870.11 $5.45 $135.00 2.20 6.25 0.90 2.50 Supplies : 60 tons coal at $2.25 10 gal. kerosene at 22 ct 25 gal. gasoline at 25 ct 10 Ib. grease at 9 ct 10 Ib. graphite at 25 ct 20 gal. engine oil at 31 ct 6.20 25 gal. cyl. oil at 44.5 ct 11.13 Total at 1.03 ct. per cu. yd. for supplies $164.18 Total cost per cu. yd. $6.48 Walking Traction for a Dragline Excavator. John W. Page, in Engineering and Contracting, July 19, 1911, gives the follow- ing: The excavator (Fig. 12) is mounted upon a turntable, which in turn is mounted on a platform consisting of I-beams. This platform is about twice as long as the turntable platform is wide. The turntable platform is arranged to roll upon it from -one end to the other. The whole is supported on two " boats " or wooden skids. In moving, the machine is run to one end of the beam platform, thus removing the weight of the machine from the " boat " at the opposite end. This " boat " is then slipped ahead by means of cables operated by the main engine. Then the machine is run to the opposite end of the beam plat- form and the opposite " boat " is slipped "forward. The opera- tion gives the machine a zigzag walking motion, advancing it about 7} ft. each time. A Caterpillar Traction Dragline Excavator. A machine made by the Stockton Iron Works, Stockton, Cal., is described in En- gineering Record, Dec. 12, 1914, by W. W. Patch. It is equipped with both a clam-shell and a dragline bucket, and weighs with either bucket about 20 tons. Its power is derived from a 20-hp. heavy-duty upright gasolene engine, operated with distillate. When traveling along the road in high gear the machine makes about % mi. per hr. Under these conditions the jack arms are removed and are carried upon the deck, thus giving a maximum width of 15 ft. 6 in. At the intersections of 60-ft. roads turns G;M HANDBOOK OF EARTH EXCAVATION of 90 can be made readily. As the distance between the two axles is over 19 ft. there are seldom any highway stringer bridges which are subjected to a span load exceeding about 12 tons. The form pf bucket bail is similar to that used in the Page drag scraper. Both clam-shell and dragline buckets were provided, but the dragline bucket was used almost exclusively. Fig. 12. Walking Attachment for Dragline Excavator. When operating under the most favorable conditions this ma- chine, with a crew of four men, has excavated 400 cu. yd. in a day of 8 hr. While for a period of seven months (Apr. to Oct., 1913) the average performance has been at the rate of 40 cu. yd. per hr., even when time lost on account of repairs and moving from place to place is included. This work was in southern Oregon. If blasting is required, or if the ground is so soft as METHODS AND COST WITH DRAGLINE SCRAPERS 635 mfsniV/* enriViKirt uj(T : 630 HANDBOOK OF EARTH EXCAVATION to require planking beneath the wheels of the machine, then the crew is increased to a total of six men. A detailed statement of the cost of operating the machine for a continuous period of seven months during this second season is given below. This statement contains a liberal allowance of $1,194 for depreciation of the plant. The total cost was $6,655 for 56,000 cu. yd. Cost per cu. yd. Labor, men $0.0476 Labor, horses 0089 Explosives 0058 Fuel, gasoline 0052 Supplies (grease, oil, lumber, etc.) C094 Depreciation, machine 0213 General expenses 0127 Miscellaneous 0018 Repairs 0061 Total per cu. yd $0.1188 The work comprised deepening an old ditch which carried drainage water constantly. The old section was about 2 ft. deep, 4 ft. wide, and had 1.5 to 1 side slopes. The new section was 5 ft. deep, 5 ft. wide at the bottom and had 1.5 to 1 side slopes. The ditch was about 4 miles long, and for approximately one-half of its length the bottom 2 ft. was in indurated materials which required blasting before it could be excavated. The crew comprised from 4 to 6 men and 2 horses at the following wages: Machine operator, $130 per month; gas-engine man, $80 per month; powder-man, $3 per day; 2 laborers, each $2.48 per day; 2 horses, each $1.25 per day. A day's work com- prised 8 hr. on the job. Jacobs Gruided-Line Excavator. In the use of the ordinary drag-line bucket excavator, difficulty is often experienced in guiding the bucket when stiff material is encountered. This diffi- culty is especially noticeable when the bucket, in cutting the sloping banks of an open ditch, passes from stiff to loose ma- terial. Recently an excavator has been put upon the market designed to overcome this difficulty. This new machine is the Jacobs Guided-Drag-Line-Bucket-Excavator, manufactured by the Jacobs Engineering Co., of Ottawa, 111. This excavator consists of a steel-framed platform made up of standard structural steel shapes, which are joined with fitting bolts. This upper platform revolves on a circular track, which rests on a lower steel-framed platform. The machinery consists of a three-drum hoist with steel gearing and the whole mounted on a heavy cast-iron base, which is bolted to the upper platform. The machine swinging drums are operated by a double-cone METHODS AND COST WITH DRAGLINE SCRAPERS 637 friction and are connected to the drum shaft of the hoisting en- gine by a sprocket and bushed chain. The distinctive feature of the machine is the guide boom, which consists of a steel girder shaped like a figure J, with the hook end hanging vertically from a straight boom. Both booms are pivoted at the front end of the upper platform. The bucket, which is a rectangular steel box, open at the end toward the machine, is attached to a trolley which travels on the guide uoom, having two double-flanged wheels riding on the upper flange and a third wheel bearing against the lower flange to keep the bucket from kicking upward. In making the cut, the bucket is hauled inward by a cable leading directly from the trolley to the engine. For dumping, it is hauled outward by the back-haul cable, which leads from the trolley to the head of the main boom and back to the engine. The bucket is dumped by con- tinuing its travel to the vertical end of the guide boom, the boom being first swung around to the position at which the load is to be deposited. The machine is self-propelling and travels on a track, which is made in sections and is moved by the machine itself. This machine has been used for the construction of open ditches, tile ditches and back tilling same, levees, roads and highways, etc. This excavator is built in various sizes, from one having a %-yd. bucket and 25-ft. boom to one with a 1^-yd. bucket and a 40-ft. boom. The cost of the machines varies from $3,500 to $6,000, depending on the length of the boom and the capacity of the bucket. At Dixon, Illinois, one of these machines constructed an open drainage ditch, having a 22-ft. bottom, a depth varying from 4 ft. to 6 ft. and iy 2 to 1 side slopes. The machine used had a 40-ft. boom, a li^-yd. bucket and was operated by a 7-in. x 10-in. double cylinder, 3-drum hoisting engine, with swinging drums sprocket driven from the front drum of the hoisting engine. The weight of the machine was about 23 tons, which included one ton of coal and 300 gal. of water. The average excavation for a 10-hr, day was 600 cu. yd. at the following cost: Operator $ 4.00 Fireman 2.50 Trackman 2.00 Coal 5.00 Oil and waste < 1.00 Water 1.00 I 1 7 I . ! $15.50 Interest, depreciation and repairs 10,00 Total per day $25.50 638 HANDBOOK 0# EARTH EXCAVATION For 600 cu. yd. this makes a cost of 4.25 ct. per cu. yd. The material excavated was 4-ft. of gumbo and the substratum yellow clay. The yardage averaged 150 cu. yd. per station of 100 ft. The labor employed consisted of an operator at $125 per month, a fireman at $2 per day, two trackmen at $1.75 per day, and a cook at $40 per month. The men were furnished \vith free board and lodging. Following is a tabulated list of expenses for 10.5 days. Labor $117.62 Coal 20.60 Coal hauling 25.00 Repairs 8.45 Camp supplies 9.72 Cook's wages 16.06 Traveling and livery 32.55 Insurance 7.14 Miscellaneous 7.14 Total, 10.5 days at $22.30 $234.28 Coal was hauled 8 miles from a railroad siding at a cost of 8 ct. per hundred-weight and part of the time at a cost of $5 per load. The item of " camp supplies " does not include some supplies used, which were on hand and not purchased during the month. " Traveling and livery " include a special trip to inspect work and attend commissioners' meeting. The output averaged 220 cu. yd. per day at a cost of 10 ct. per cu. yd. The foregoing data are from " Excavating Machinery " by A. B. McDaniel. A Locomotive Crane Used as a Dragline Excavator. Engineer- ing and Contracting, May 10, 1911, gives data on the use of a locomotive crane on the New York State Barge Canal. This crane was bought to use for concreting, and while waiting for concreting to begin was rigged as a dragline excavator. It dug a channel 60 ft. wide on top, and 20 wide on the bottom, with an average depth of cut of 9 to 10.5 ft. and a length of 2,600 ft. The crane began on April 14 and, in the 12 working days of the month, excavated about 6,000 cu. yd., according to the state engineers' estimate. There were two crews employed, each work- ing 8 hr., and comprised as follows: 1 engineman at $100 per month. 1 fireman at $50 per month. 4 laborers at $1.60 per day. The average cost of moving dirt has been about 9^ ct. per cu. yd. The crane is a standard Brownhoist crane with 50 ft. of boom METHODS AND COST WITH DRAGLINE SCRAPERS 639 built to handle 3 tons at a 48 ft. radius, with 12,000 Ib. of ballast in the buck frame. Dredging Gravel with a Weeks' Bucket. Engineering and Contracting, Feb. 5, 1913, gives the following. (See also Apr. 26, 1911.) Gravel for building purposes for the city of Van- couver, B. C., is obtained in part from submerged deposits, one of which lies at the mouth of Indian River at the head of the North Arm of Burrard Inlet. To obtain the gravel from this place over which the tidal range is about 12 ft., a Weeks patented bucket has been used in various ways since the spring of 1910. 14. Gravel Dredging and Washing Scow Equipped with Weeks Two Line Bucket. First Plant. The first method of operating the bucket was from a skid A-frame mounting a swinging boom, on a scow. The bucket with its load is lifted and swung over the scow to be emptied and returned to its loading place by means of a %-in. back-haul line passing from the hoisting engine over a sheave sup- ported by a float suitably anchored. The bucket has a capacity of 24 cu. ft., and 35 cu. yd. of gravel per hr. is loaded when the distance the bucket transports its load is not over 200 ft. It may be noted here that the tendency with this shovel wher- ever installed has been to make it a transporter of material as well as an excavator, with the inevitable result of reduced capa- city and increased wear. The operating crew consists of a foreman, engine runner, fire- man and laborer, the principal duty of the latter being to spring the latch on -the bucket which causes it to dump its load. An 8^4 x 10-in. double drum hoisting engine burning 1^> tons G40 HANDBOOK OF EARTH EXCAVATION of coal per 10-hr, day, when working steadily, supplies the power. Through the top of the A-frame, a heavy link passes, at the rear end of which the backstays are fastened, and from the front end the boom hangs by means of a special shackle, the pin of which is enclosed by a couple of wearing sleeves. These sleeves are made of pipe and take the wear due to the swing of the boom. If kept well greased this wear is very small. At the point of the boom is a three-armed forging, the arms of which are set at equal angles. To the top arm is fastened the boom line of fixed length, and to one of the lower arms is hung a sheave for the %-in. main line to the bucket. At the base of the boom is bolted a heavy bent plate, the long end of which fastens to the boom. The short end pivots between two angles riveted to a heavy plate which is bolted to the bottom of the A-frame. When the load comes upon the end of the boom, its tendency, by reason of the eccentrically suspended load, is to swing toward the side on which the main line sheave is hung, and this tendency is in- creased as the scow tips. A fair leader for the main line, hung in the A-frame, prevents this tendency from being excessive. With this arrangement of boom and tackle, no swinging gear is necessary. The sweep of the loaded bucket over the scow is regu- lated to a nicety by the engine runner paying out the back haul. The daily cost of operating is as follows: 1 foreman $ 4.75 1 engine runner 4.50 1 fireman 3.00 1 laborer 2.75 1V 2 tons coal at $8 12.00 Wear and tear, depreciation, etc 3.00 300 cu. yd. at 10 ct $30.00 Second Plant. Later a larger, but in every way similar, dredge was installed, and the original rig mounted for a time on pile bents instead of a scow. The object of this change was to facilitate washing and storing the gravel, which was done with a special type of washer, and the washed gravel elevated into bunkers. " Owing to a desire to reclaim all the gravel possible from the fixed location of the dredge, the distance which the bucket hauled its load was made nearly 300 ft., which was too great to attain a large output. The depth of the pit to which dredging was carried was about 60 ft. below low tide. From 225 to 240 trips of the 1%-cu. yd. bucket was all that could be averaged in 10 hr. Considerable time was lost, due to clogging of the washer by over-feeding. About 40 cu. yd. could be dredged per hr., washer' permitting. The same crew was used as on the floating dredge, but the daily consumption of coal was greater by METHODS AND COST YVT1H DRAGLINE SCRAPERS 641 642 HANDBOOK OF EARTH EXCAVATION Uu < half a ton. The cost per cu. yd. was 9 ct., including all expenses. Improved Plant. Wishing to reduce the length of haul, with its attendant wear and diminished output, a new method of oper- ating has been devised, so that now the bucket digs under the scow (Fig. 14) upon which the washer also is mounted. An in- clined trolley track projects beyond the front of the scow upon which runs a trolley car carrying a large sheave over which passes the main-haul lines. The trolley is locked at the lower limit of its ; Fig. 16. Page Scraper Bucket. run while the bucket is diggingj and is unlocked by the bucket striking the releasing leversl Upon being unlocked, the trolley runs up the inclined track, the bucket being hung meanwhile from the trolley car by two hooks upon which it adjusts itself automatically and which prevent it from lowering or twisting. Arrived at the upper limit of its travel, the bucket dumps into a hopper, whence the gravel is conveyed by a belt to the washer. The bucket and trolley are -then lowered to the bottom of the incline, and the bucket returned to its loading position by the back haul which passes over sheaves at the back of the dredge. Springs in tension absorb the shock of the descending trolley METHODS AND COST WITH DRAGLINE SCRAPERS 643 car. The scow is held by adjustable anchor lines passing over the front corners and the middle of the stern. The bucket now in use holds 1^ cu. yd. and averages 50 sec. per trip. Owing to a lack of sufficient scows for loading, no positive statement of its daily capacity can be made at this time, but it is known to be much faster than either of the other methods of operating. At present, the same crew as before operates the dredge, including the washer; but later, when the output becomes larger, an additional man may be required to assist in spotting scows. The Weeks bucket is made by the Moran Co., of Seattle, Wash. Dragline Excavator Buckets. They are of various shapes and are arranged either to tilt forward or rearward in dumping. The Page scraper bucket is illustrated in Fig. 16. It is dumped for- ward by holding the hoist line and slackening the pull line.' PAGE SCRAPER BUCKETS Width of Capacity cutting edge Weight cu. yd. in. Ib. % 36 1,450-2,200 1 45 1,500-3,500 1% 45-48 1,700-4,000 1% 2 48 51 2,000-4,500 3,000-6,000 5T 2% 57 5,850-7,000 3 60 6,550-7,500 3% 60 7,000-8,000 4 60 8,600 4% 66 9,100 List prices, 1916 $ 495- 575 546- 800 573- 8<5 610- 9^8 750-1,0*4 1,036-1,250 1,180-1,407 1,313-1,563 1,688 1,813 1,938 EMjKMta Fig. 17. The Holcomb Bucket. The Monighan 2-line drag bucket is somewhat like the Page bucket. The Iverson is similar in form but is dumped by a third or latch line. The Hayward and Wenks buckets are dumped for- 644 HANDBOOK OF EARTH EXCAVATION METHODS AND COST WITH DRAGLINE SCRAPERS 645 ward by pulling on the tail or hoist line, but the latter may be dumped backward by hauling 1 on the pull line and slackening the tail line. The Browning bucket is dumped by a third line. In all, except the Iverson and Browning buckets, the drag line must be held against the lift line to prevent dumping. The Sauerman drag line excavators are operated by one pull- line and a slack cableway. The bucket is drawn in one direc- tion by the pull-line and allowed to slide in the other direction along the tightened cableway under the influence of gravity. It is dumped (either forward or backward according to the type) by encountering a stop on the cableway line. The prices of these machines depend upon the length of span, size of bucket, and local conditions. A %-yd. excavator of 500-ft. span cost about $2,200 in 1916, and a 1^-yd. machine about $4,200, in- cluding cables, buckets, hoist and boiler, but not anchors, mast or tower timbers. The capacities vary from 10 to 80 cu. yd. per hr., depending on the size of the bucket, kind of material, and other conditions. With an average haul of 300 ft., about 35 cu. yd. per hr. per cu. yd. of bucket capacity will be averaged. About 30 hp. per cu. yd. of bucket capacity is required. The Dunbar Dragline Bucket. This is described in Engineering News-Record, July 8, 1918. The bucket will take a load in travel- ing its own length, and then can be hoisted at once instead of being pulled to the bank of the drag line. The end gate holds the load, but at the same time allows water to escape. Experi- ence showed that the cables lasted longer and the machine con- sumed less coal than when an ordinary bucket was used. These buckets were designed by H. T. Dunbar, president of the Dunbar & Sullivan Dredging Co., Buffalo, N. Y. They were made at the company's machine shops on the work at Waterford, N. Y. They are of 3-yd. capacity. tringers Fig. 19. Planking for Dragline Excavation Work Over Soft Ground. Planking for Dragline Work Over Soft Ground. Engineering and Contracting, Dec. 16, 1914, gives the following: The sketch (Fig. 19) shows a method of planking for dragline excavation work for drainage ditch near Viro, Fla. The ground consists of a top layer of vegetable fiber on which a man can stand in most 646 HANDBOOK OF EARTH EXCAVATIOK places, but which will not carry a team. A C-ft. bar can be shoved down its whole length with one hand. On 6 x 6-in. string- ers laid parallel to the direction of movement are laid platforms of 3 x 12-in. x 12-ft. planks set close, and at the center of each platform is laid a roller track of three 6 x 12-in. x 14-ft. timbers set close. These track timbers are staggered to distribute the load to the plank. The stringers are pressed down into the ground by the weight of the excavator and apparently so confined the material as to prevent it from squashing out sideways under the ends of the planks. The stringers have to be dug out to be shifted ahead, but the planks can be easily picked up. Four pit- men pile the plank in bundles behind the machine which, with a chain hooked to the bucket, picks up the bundles and swings them ahead for the pitmen to relay. The four pitmen, with the use of the machine as described, pick up and relay the stringers, plank and track timbers as fast as the machine can work. ' ' Machine should go in fhisairecnon -- *% v l'U-8olt } i t $ xiy Machine Bolts (CYskHeads> Ends of bottom planks are shown by dotted linels Top Timber S'x 6"x 2 ' ffii/ii-' Total per month $1,892.50 Using 31,191 cu. yd. excavated for Section 4 and 25,214 cu. yd. excavated for Section 5, the costs per cu. yd. are estimated as follows : G50 HANDBOOK: OF EARTH EXCAVATION Section 4 Cost per cu. yd. Labor $0.061 3 tons coal per day 0.010 Repairs and miscellaneous supplies 0.048 15% annual interest on $15,000 plant 0.006 50% annual depreciation on $15,000 plant 0.02 Total cost per cu. yd $0.145 Section 5 Cost per cu. yd. Labor $0.076 3 tons coal per day 0.012 Repairs and miscellaneous supplies 0.059 15% annual interest on $15,000 plant 0.007 50% annual depreciation on $15,000 plant 0.030 Total cost per cu. yd $0.184 The labor item includes all work done, such as repairs, moving machine, and actual excavation. The repair and miscellaneous supplies item is large. It con- tains new cable, oil, renewals and 2 miles of 2-in. pipe to supply water to the boilers. The strains and work demanded of large dragline machines are heavier than that of steam shovels. The average repair and maintenance bill has been $1,500 per month. Dragline Excavator Work at Stockton, Cal. Engineering and Contracting, July 20, 1910, describes work on a diverting canal built to prevent floods at Stockton, California. The canal is 5.25 miles long with a cross-section 150 ft. wide on the bottom, and with side slopes of 1 to 1^. Two dragline excavators were used, one a Hey worth-Newman machine having a 100-ft. boom and a 3}-cu. yd. bucket. The second machine had a 110-ft. boom and had been converted from clam-shell to dragline rig. It used a 2^-cu. yd. bucket. The method followed in doing the work was to set up the Hey- worth excavator 7 ft. from the center line of the channel in order to control the excavation of the outer 30 ft. opposite the levee side. This allowed the boom to deposit the spoil on the levee site clear of the berm. When about 2,000 ft. of progress had been made in this manner, the machine was placed in about 31 ft. and another section was taken out up to 7 ft. of the levee side. The converted clamshell machine followed, taking out the rem- nant. The excavating machines were all mounted on rollers, made of 8-in. extra heavy hydraulic pipe, with pine centers pressed in, and were moved forward on 12x14 in. timbers. The organization under which the work was done consisted of the following: METHODS AND COST WITH DRAGLINE SCRAPERS 651 1 superintendent. 2 captains, 1 on each machine. 3 leveemen, 6 hours on and 12 off. 2 mates, 1 on each machine. 4 firemen, 2 on each machine. 8 deckhands. jasr* 1 cook. 1 flunkey. 2 pumpmen. 1 handyman. 1 team of 6 horses for hauling oil and freighting. The expenditure per month was as follows: hy Jo7 91 -i(!j V/o!:>h01Ij T>ijqif) JHO (Tf; iril.-ll lllJ.'dvf VjiV.'^IlilJ'Jft'M! >n['\ . ,l,,l v Iti r.K The total cost per cu. yd. of contract yardage was 10.5 ct. This shows that it was necessary to make 42% excess exca- vation with the drag line machine. Five Examples of Cost of Dragline Excavation. D. L. Yarnell, in Engineering and Contracting, Feb. 2, 1916, givas tho following: Job 1. A dragline excavator of the rotary type, having a 2-yd. scraper bucket and a 60-ft. boom, was used in the construction of drainage ditches in southern Texas. It was built mostly of wood and moved on rollers. Power was derived from an 80-hp. internal-combustion engine, burning oil. The cost of the exca- vator, ready to operate, was $12,000. It was operated about 10 months in two daily shifts of 10 hours each, a shift consisting of 10 men. The actual working time was not recorded. The ditch ranged from 4 to 22 ft. in bottom width, from 3 to 12 ft. in depth, and had 1 to 1 side slopes. The soil varied from a stiff, heavy clay to a fine sand. The excavation amounted to 230,000 cu. yd. The cost was as follows: 656 HANDBOOK OF EARTH EXCAVATION Operating expenses $22,.'513.:)6 Miscellaneous expenses :'74.70 Interest and depreciation 4,100.00 Total $26,788.06 Cost per cu. yd., $0.1164. Job 2. On another drainage project in southern Texas, a 2-yd. rotary excavator was used. The machine was of steel throughout, had a 60-ft. boom, and was mounted on caterpillar traction. The crew consisted of a foreman, operator, engineman, oiler, and two laborers. The machine was operated by a 110-hp. internal-com- bustion engine, with oil as fuel. The total cost of the machine was about $17,500. The cost of erection was $509. During the four months of operation two 10-hr, shifts were run. The ditches ranged from 4 to 22 ft. in bottom width and from 3 to 12 ft. in depth, with 1 to 1 side slopes and 8-ft. berms. The material excavated was a stiff, heavy clay. The excavation amounted to 91,400 cu. yd. The cost was as follows: Operating expenses $ 8,873.82 Miscellaneous 371.00 Interest and depreciation 2,391.00 Total $11,635.82 Cost per cu. yd., $0.1273. Job 3. In the same general locality as the last example a 1%-vd. rotary dragline excavator, operated by a 50-hp. internal- combustion engine and mounted on caterpillar traction, was used in the construction of some ditches in soil ranging from stiff, heavy clay to fine sand. The dutches were of the same dimensions as in Job 2. The machine was rebuilt from an old dipper dredge at a cost of about $1,200. It was operated in two daily shifts of 10 hr. each. The crew for each shift consisted of from five to six men. During the five months of operation the machine moved 59,014 cu. yd. at an expense, exclusive of interest and depreciation, of $8,921, or $0.1512 per cu. yd. Job 4- A rotary dragline excavator with a 2% -yd. bucket and 65-ft. boom, mounted on skids and rollers, was used in the exca- vation of 222,500 cu. yd. in South Dakota. The power was ob- tained from a 50-hp. internal-combustion engine, using gasoline. The cost of the machine, complete, was $10,500. The total time of construction was 148 working days, or approximately six months, of which 23 days were occupied in making repairs. Two shifts of 11 hr. each were run. The soil was a loam under- lain by clay. The crew and rates per month were as follows: One superintendent, $125; 2 cranemen, at $100; 4 trackmen, at $50; 1 teamster, $45; 1 cook, $40. The operating expenses were as follows: METHODS AND COST WITH DRAGLINE SCRAPERS 657 Gasoline, 15,444 gallons, at $0.124 $1,915.05 Labor 3,060.00 Subsistence 56181 Cables 978.87 Repairs and renewals . 845.93 Miscellaneous 2,078.72 Interest and depreciation 2,152.50 Job 5. The following costs were secured on the operation of a rotary dragline excavator with an 85-ft. boom, 2-yd. bucket, and a 50-hp. engine. The work was done on the New York State Barge Canal. The machine weighed 147 tons and cost $10,000. It excavated earth 90 ft. from center on one side and deposited it 100-ft. from center on the other. It dug a channel 25 ft. deep and deposited the material on waste bank 15 to 25 ft. high. The material was a stiff clay, with few stumps or boulders. The following is a condensed cost record for five months' work: Total Yards for month excavated April $1,088.21 5.205 May 1,041.53 18,365 June 1,152.04 25,333 July 1,317.61 33,055 August 1,535.36 47,363 Average cost per yd. for 5 months, including all charges, $0.047. In May, items of cost were as follows: Engineman, at $90 per month $ 90.00 Engineman, at $95 per month 84.04 Fireman, pumpmen, watchmen, etc., at $1.75 per day 363.00 Coal, at $3 per ton 147.00 Repairs, including labor and material 15.82 Interest and depreciation 341.67 Total for May $1,011.53 Large Electric Dragline Excavators. Engineering and Con- tracting, Jan. 22, 1913, gives information as to 'Lidgerwood-Craw- ford machines built for use on the Calumet Sag Channel, in Chicago. The machines weigh 120 tons each, and operate 2}-cu. yd. Page buckets on 100-ft. steel 1. corns. The arrangement of the operating machinery is shown in Fig. 24. The double drum hoist is operated directly by a gear on the shaft of a 112-hp., 60-cycle, 3-phase motor, making 690 r.p.m. A 52-hp., 60-cycle, 3-phase motor, 855 r.p.m., operates the bevel swing gear as shown. The air brakes are operated through power furnished by a 25-cu. ft. motor-driven air compressor. The current is furnished by a public service company and is brought from Blue Island, several miles away, over a high tension line at 33,000 volts to a transformer house on the work 058 HANDBOOK OF EARTH EXCAVATION METHODS AND COST WITH DRAGLINE SCRAPERS 659 where the voltage is stepped down to 2,300 volts. It is again stepped down to 440 volts through a portable transformer which is attached to the dragline machine by a cable and is pulled along on its trucks as the machine moves ahead. On the machine the current is stepped down to 110 volts for the incandescent lamps and to 35 volts for the searchlight which is placed on the front of the house and just under the boom. The machine is operated by two men on board and two men outside for handling the track. While moving to position for commencing work one of the machines was moved 410 ft. in one day. Elsctric Draglines on the Sun River Irrigation Canal. Owing to the distance of this work from the nearest railroad and diffi- culty of hauling over poor roads, electric power was adopted for all machinery. Engineering Record, Jan. 29, 1916, gives a description of the work. Current was obtained from the Great Falls Power Co.'s plant at Rainbow Falls, 75 miles away. It was transmitted at 48,600 volts over wires strung on 45-ft. cedar poles with a span length of about 350 ft. Each conductor was three-strand copper wire, carried by suspension insulators on wood cross arms. A fourth stranded steel cable was grounded at each pole to help keep the line clear of static disturbances. At canal miles 1, 20 and 36 power was delivered to substations of 700 to 1,600 kva. capacity, where the voltage was reduced from 48,600 to 16,500 for distribution along the canal. The distribu- tion line was on 30-ft. fir or cedar poles with span lengths of 150 ft. The circuit was three copper wires with pin-type in- sulators on single wood cross arms, and no ground wire was used. Two Bucyrus dragline machines were used for excavation. The larger was Model 24 equipped with a 100-ft. boom and an extra heavy 3^-yd. Page bucket. The smaller machine was Model 20 with 85-ft. boom and 2^-yd. bucket. For transforming the 16,500- volt line current down to the voltage required by the mo- tors, two sets of transformers were required. One set, stepping from 16,500 to 2,200 volts, was mounted on heavy trucks and hauled along by teams as the work proceeds. Connection was made to the 16,500-volt line at some convenient point and cur- rent transmitted at 2,200 volts through a triple-conductor, steel- armored cable to the second set of transformers. These were mounted under the floor on the frame of the machine, and step the current down to the 440 volts required by the motors. The steel cable was about 1,000 ft. long and obviated the necessity of moving the high-tension connnection when the line was alive, 660 HANDBOOK OF EARTH EXCAVATION as the machine could move along 1,500 ft. or more without moving the transformers. Roads for Sideh.ill Work. It was expected that the handling of the machines on sidehill slopes as steep as 2^:1 would be slow and probably dangerous. Whenever sidehills were encountered the machines were used to excavate and level ahead of themselves a road from 30 to 35 ft. wide, on which the timber track was laid. This advance grading was at such elevation as would pro- duce the most efficient work of the bucket and still keep the track excavation within the lines of the completed canal, thereby ren- dering unnecessary any non-productive excavation by the ma- chines. At several points on the canal the upper cuts were as great as 90 ft. By excavating the grade of the track 50 ft. above canal grade, however, the upper part of the slope was excavated without double handling of the material. The engi- neers state that the machines far exceeded the expectations of the contractors in their ability to dig down on a 1^:1 slope and load the bucket to capacity. The material excavated varied from a gravelly loam to cemented gravel, glacial drift and sandstone, and the topography from a level prairie to a steep, rocky hillside with transverse slopes of 2^:1. In the heaviest material blasting was resorted to, but in several instances the machines have dug 8 or 10 ft. of seamy sand- stone without the use of explosives. About 1,500,000 cu. yd. of excavation has been handled by these two machines in two seasons, and costs are given here for some of the work, showing the nature of the material handled and the working conditions. Power consumption has varied from 0.8 to 3.0 kw.-hr. per cu. yd. of material moved, depending on the nature of the material. No attempt was made to obtain record-breaking outputs for the machines, as it was realized that with frequent moves, rough topography and the condition imposed of placing the material so as to produce a watertight bank, outputs would not be compar- able with those of machines working in a large pit and wasting the material or loading it into cars. Outputs of 1,450 cu. yd. per 8-hr, shift and 32,000 cu. yd. per shift per month have, however, been obtained under the above conditions. The crew required to operate a machine for one shift has been one operator at from $175 to $200 a month, one oiler at $2.50 a day, four track- men at from $2 to $2.50 a day and one team to move track timbers, etc. Electrical work for all shifts has been performed by an electrician or electrical foreman who received from $150 to $175 a month. Interest on investment includes all charges for insurance, bond premium and interest on cash capital required. Preparatory ex- METHODS AND COST WITH DRAGLINE SCRAPERS 661 pense includes all charges for the delivery and installation of plant and accessories. Plant depreciation includes all charges for repairs and depreciation of tools and machinery. Under the classification adopted for excavation, class 1 includes all ma- terial that can be plowed to a depth of 6 in. with six animals of 1,400 Ib. or over, and boulders of less than 2 cu. ft.; class 2 includes indurated material that cannot be plowed to a depth of (3 in. with six animals, but after being loosened can be exca- vated by teams and scrapers, and also boulders from 2 to 10 cu. ft. in size; class 3 is rock in place not included in classes 1 and 2, TABLE I. EXCAVATION COSTS IN CENTS PER YARD WITH MODEL 24 ELECTRIC DRAGLINE VALUED AT $36,326 Class 1, Class 2, Class 3, 333,689 23,319 39,045 cu. yd. cu. yd. cu. yd. Interest on investment 0.81 Preparatory expense 1.33 Plant depreciation 3.63 Executive 0.89 Labor 5.98 Electric power 0.73 Supplies 1.13 Miscellaneous 0.16 1.21 2.25 1.99 4 3.73 5.41 10.12 1.24 3.09 7.85 21.03 1.03 1.82 1.67 6.72 0.15 0.29 Total 14.66 20.55 49.05 TABLE II. EXCAVATION COSTS IN CENTS PER YARD WITH MODEL 20 ELECTRIC DRAGLINE VALUED AT $20,957 Class 1, Class 2, Class 3, 410,747 4,180 9,546 cu. yd. cu. yd. cu. yd. Interest on investment 0.44 0.76 1.61 Preparatory expense 1.12 1.20 2.52 Plant depreciation 1.86 3.22 6.79 Executive 0.71 1.31 3.14 Labor 3.70 8.22 15.77 Electric power 0.78 V78 2.80 Supplies 1.29 1.53 7.50 Total ., . 9.90 18.02 40.13 Costs for the Model 24 dragline are for the construction of 2 miles of canal on heavy sidehill and % mile of canal entirely in cut. The sections excavated were from 12 to 22 ft. in bottom width with side slopes of 1:1 and 1^:1. Costs include the hand trimming of 9,000 ft. of the canal for placing concrete lining. Costs for the Model 20 dragline are for 5 miles of canal with 22-ft. bottom, and 4 miles of canal with 27-ft. bottom. Side slopes in both cases are 1^:1. The topography was rough, rolling foothill country, with the surface covered with large boulders. About 25% of the canal was wet in the bottom from .springs. 602 HANDBOOK OF EARTH EXCAVATION Steam and Electric Draglines on N. Y. Barge Canal.' Work done 011 Contract 42, New York State Barge Canal, was partly done by dragline excavators. According to Engineering and Con- tracting, Sept. 28, 1910, the material handled consisted largely of black gumbo, near Utica. The following data show the costs of excavation per cubic yard for the month of April, 1910. These costs include labor, repairs and distribution of field office expenses: Hey worth-Newman Excavator, 100-ft. Boom; 2Ms Yd. Bucket: 1 operator $ 4.00 1 foreman 2.00 5 laborers 7.50 1 foreman, average $85 per month 2.83 1 pumpman 1.50 1 oiler 2.00 1 team 1 shift a day 4.50 Total cu. yd. for April 23,192 Total cost for April $1,983.84 Total cost per cu. yd $ 0.085 Hydraulic Dredge "Mohawk," 12-in. suction: 1 captain, per month $ 150.00 3 enginemen, per month 75.00 3 levermen, per month 110.00 1 mate, per month 120.00 6 deckhands, per day 2.00 3 firemen, per day 2.00 8 laborers or pipemen, per day 1.60 Total cu. yd. excavated 15,557 Total cost $1,726.30 Cost per cu. yd $ 0.111 Two Lidgerwood Excavators, Electrically Operated, with 25 hp. Motor for Swinging and 125 hp. Motor for Hoist; 2y 2 Yd. Page Bucket: 1 operator, per day $ 4.00 1 oiler, per day 2.00 5 laborers, per day 1.50 1 sloper, per day 1 foreman, $85 per month 2.83 1 electrician, $125 per month 4.17 Total cu. yd. excavated Machine No. 1 2,271 Total cost $1,667.80 Cost per cu. yd $ 0.735 Total cu. yd. excavated by Machine No. 2 2,583 Total cost $ 992.30 Cost per cu. yd $ 0.384 The two Lidgerwood machines worked only part of the time during this month, No. 1 working 13 days and No. 2 working 10 days during the month. Both were engaged in moving to new positions and were working at a disadvantage. The yardage for these machines should be about the same as for a Hey worth- Newman machine under similar conditions. The difference in daily pay roll is, however, in favor of the electrically driven ma- chine. METHODS AND COST WITH DRAGLINE SCRAPERS C63 The electric power on these machines costs about 1 ct. per cu. yd. City current is used and a transformer is placed at con- venient points along the line, as the machine moves ahead. The repairs on the Hey worth machine have averaged, approx- imately, $400 per month. The highest amount charged to repairs for any one month is $667. Another machine used on this work was a cableway with drag- line bucket. It consists of a movable tower, located on one side of the canal with a cable running from it to an anchorage on the opposite side of the canal. The drag bucket is supported by and slides up and down this cable. It is pulled back and forth by an endless line. 'The crew and costs are as follows: 1 operator, per d?y $ 4.00 1 tiVeman, $75 per month, per day 2.50 1 foreman or supt., $200 per month, per day 6.67 1 pumpman, per day 1.50 6 laborers, per day 1.50 Total cu. yd. exca'vated 15,065 Total cost , $1,455.81 Cost per cu. yd $ 0.096 This tower is 85 ft. high and operates a 1%-cu. yd. bucket with a 10xl2-in. hoisting engine and 40-hp. boiler. This machine is becoming quite popular along the canal because of its adaptability and its moderate cost. Steam and Electric Draglines on Ditch Work. F. N. Cronkolm, in Engineering Record, Dec. 26, 1914, gives the following: The operation of steam and electric dragline excavators and an elec- trically-driven suction dredge are described and costs of excava- tion given for the Mindoka Reclamation Project, Idaho. Five excavators were in service on the project. Two steam dragline machines were started in 1910 and 1911. A small suc- tion dredge was started in the spring of 1913 and two electric dragline excavators were started in Sept., 1913. Steam Machines. The steam dragline machines were of the ordinary standard type and were built on the project. They have revolving frames, rope-swing, 1-yd. bucket and a reach from the center bearing to the end of the boom of 58 ft. The machine was mounted on rollers supported on planks. The approximate cost of the machine was $5,000. The suction dredge was also built on the project. It consisted of a boiler and an engine direct-connected to an 8-in. centrifugal sand pump, mounted on a 10 x 30-ft. scow. The 40-ft. discharge pipe was counterbalanced by a weight suspended from a pole on the opposite side of the boat. The material was discharged back of a levee built along the line of the proposed construction. The Total for 8 years $422,679 682 HANDBOOK OF EARTH EXCAVATION Number of cu. yd. dredged 5,603,401 Number of hours worked 31,670 Cost per cu. yd., ct 7.54 Vacuum Pump and Delivering Dredge. A dredging apparatus used at Far Rockaway, Long Island, N. Y., was described in Engineering 'Sews, June 13, 1895. The dredge consisted of a large rectangular hull with two derrick towers at the bow end, each one of which handled an orange-peel bucket. The equip- ment throughout the dredge was in duplicate. The material was dumped into hoppers or receivers from each of which a pipe led to the pumping apparatus. This apparatus was a Hussey pump practically on the same plan as the old Savary pump or modern pulsometer, the suction being obtained by means of a vacuum and the discharge through direct steam pressure. The plan of working was as follows: When the hopper was filled with sufficient material to fill the pump, a vacuum was created by a water supply condensing steam in a chamber, and the load was driven into the pump by the pressure of the outside air. Steam at 10 to 100-lb. pressure (according to the height of lift and the length of the discharge pipe) was then admitted. This forced the material through the shore delivery pipe. Both pumps discharged into the same pipe, thus keeping the column moving at a fairly constant rate. Both the Badger and Riker pumps worked on the same plan, but discharged the material into chutes. At Rockaway the orange-peel buckets were from 4.5 to 6 cu. yd. in capacity. The hoisting engine had a cylinder 14x18 in.; the vacuum pump has a 28-in. cylinder; the steam pressure was 18 to 35 Ib. per sq. in. The discharge pipe was 2,500 ft. long. With the pump making 1.5 to 2 strokes per min., in material con- sisting of. 70% sand and gravel, and 30% mud, 500 cu. yd. per hr. were dredged. The apparatus handled large stones readily. The material, as delivered from the pipe, was 50% water and 50% solid matter. On the Massena Canal a special designed dredge of somewhat similar type as the above described machine was used. This dredge was equipped with rotary cutters and disintegrating water jets. The material was dredged with 4-cu. yd. orange-peel buckets dumping into hoppers, and thence fed to centrifugal pumps. John Bogart, in Engineering News, Oct. 30, 1902, stated that these machines could handle the softer material, as a whole, but the vacuum method of transmission was a failure, the clay forming into balls in the hopper instead of remaining sus- pended in the water. While clay will form into balls in centrifugal dredges it will pass through the pump and pipe line. METHODS AND COST OF DREDGING 683 Cost in Clay with a Large Clam-Shell Dredge. The following is given by Emile Low in Engineering Xews, Oct. 11, 1906. The Buffalo breakwater was composed in part of a rubble mound resting on a sand foundation. This foundation was dumped from scows as soon as possible after a trench had been dredged to receive it. The natural material composing the bot- tom of the harbor was chiefly a moderately stiff red clay, mixed with some blue clay, the weight in general being about 3,300 Ib. per cu. yd. Overlying the clay was a layer of sand 1 or 2 ft. thick, and underlying it, next to the bed rock, was a layer of hard, blue clay, mixed with broken stone or gravel, with boulders in places. The material was excavated from depths up to 70 ft. The dredge built for excavating this trench was a 10-yd. clam- shell dredge, operated by an 18 x 24-in. main engine, and two sec- ondary 10 x 12-in. engines, supplied with steam from two boilers. The dredged material was transported to the dumping ground, 10,000 ft. distant, in 1 hr. 6 min. Three steel scows, each hold- ing an average of 400 cu. yd. were used. During the season (from May 5 to Oct. 16, 1899), 316,343 cu. yd. scow measure, or 286,335 cu. yd. place measure, were dredged. This shows an increase of scow over place measure of 10.48%. The crew employed and their monthly wages were as follows : 1 r u nner $90 1 second runner .'.... 35 1 fireman 35 1 deckhand 35 1 greaser . 30 1 watchman 30 7 deckhands at $30 210 1 cook 30 1 cook's helper 15 Total monthly wages $510 The work began at 5 A. M. and ended at 7 P. M. with 1 hr. out for two meals, leaving a net working day of 13 hr. For working overtime the men received 15 ct. per hr. Subsistence cost $12 per month per man. One-half the wages of the superintendent or $62.50 per month was charged to dredging. The cost of fuel was 0.55 ct. per cu. yd. dredged. Pumping of dredges and scows was performed by a steam siphon rigged up on an old dredge. The cost per month was $40 for 1 man, plus $30 for 20 tons of coal at $1.50, a total of $70. New steel cables cost $100 per month ; oil, grease, waste, etc., $20; blacksmith shop, $175; hemp lines, cables, etc., $40; miscel- 684 HANDBOOK OF EARTH EXCAVATION laneous expenses, $50; yard expense, $100 per month. Range piles and buoys cost $256 for the season. Small tugs with coal, $20 per day; large tugs, coaled, $25; larger tugs, coaled, $30 per day. The approximate value of the plant was as follows: Clam-shell dredge $60,000 3 steel dump scows 32,000 Total plant $92,000 . i* O{f j ; [(..,! The annual depreciation at 10% amounted to $0,200, and the annual interest at 6% to $5,520, a total of $14,720. The cost of the work during the season of 1899, was as follows for 316,343 cu. yd. scow measure. Per cu. yd. Superintendence $0.001 Wages 0.009 Board 0.003 Coal 0.005 Towing, tug hire 0.018 Syphoning 0.001 Cables, main, steel 0.002 Lines, ropes, etc., hemp 0.001 Blacksmith shop 0.003 Yard expenses 0.002 Miscellaneous expenses 0.001 Range piles and buoys 0.001 Total operating charges ($14,702) $0.047 Depreciation and interest ($14,720) 0.046 Total cost ($"9,422) ' $0.093 The above does not include overhead expenses, dockage, heavy repairs and renewals, insurance, cost of getting to and from the work, preparatory expenses, etc. The contract price was 18 ct. per cu. yd. During the five months of the season of 139 working days, 1,121 hr. were actually worked, and 801 hr. were lost on account of delays. During this period 952 scows, holding an average of 332.3 cu. yd. each, were loaded in the average time of 1.18 hr. per scow. The average number of hr. worked per day was 8; the average ampunt dredged per hr. worked was 282.1 cu. yd., and per day was 2,263 cu. yd. The maximum day's work was 5,037 cu. yd., and the maximum hr. work was 438 cu. yd. The delays were as follows: Hrs. Dredge : Repairs to cables, bucket, engines, boilers, frame and boom, general 140 Anchors and attachments 7 Scows: leaking, repairs, pumping, delays, tug delays 59 Rain, fog, sea , , 322 METHODS AND COST OF DREDGING 685 Moving and placing 68 Meals 125 Miscellaneous 37 Holidays 43 Cost with Clamshell Dredges at Vicksburg. H. St. L. Copee gives the cost of dredging in Vicksburg harbor in 1888, in the discussion of a paper published in Transactions American Society of Civil Engineers, Vol. 31, 1894. The machine used was a clam- shell dredge. The daily (2 shifts) cost of the work was as fol- lows per 24 hr. : 16 laborers at $30 per month $ 16.00 2 enginemen at $60 per month 4.00 2 captains at $125 per month 8.25 2 cooks at $45 per month 3.00 Dredge total $ 31.25 6 men at $30 per month $ 6.00 2 captains at $125 per month : 8.25 2 cooks at $45 per month 3.00 2 engineers at $60 per month 4.00 Tug total $ 21.25 Subsisting 36 men (including 2 inspectors) at 50 ct... 18.00 Coal for dredge and tug (6 tons) 25.00 Incidentals, repairs 10.00 53.00 Total per 24-hr, day $105.50 The average monthly output was 55,529 cu. yd. (scow measure) and the cost 5.5 ct. per cu. yd. This cost does not include in- terest or depreciation, or the cost of getting 'the dredge to the working locality. The depth of water was 35 ft. The material dredged was mud and silt. The dumping ground was 1^ miles distant. Low Cost with an Orange-Peel Dredge. According to a letter of A. M. Shaw, Engineering News, Apr. 30, 1914, the following is the cost of operation of a 1^-cu. yd. orange-peel dredge during a run of 15X4 months. /^r $ 6 458 64 Fuel 4 776 09 Main hoisting cables 1 Oil 04 2 184 19 , ... 280 08 Miscellaneous suonlies . 357.36 General (includes board of crew and operation of gasoline tenders, etc.) 2,175.41 Estimated amount of supplies used in above time, but paid for by vouchers of following month (liberal estimate) 1,200.00 Total operating charge $18,442.81 686 HANDBOOK OF EARTH EXCAVATION Miscellaneous and Overhead Expenses: Proportion of cost of running main office and engineering force. $ 3,050.00 Interest on cost of dredge at 5% ; 1,080.00 Depreciation at 6% 1,300.00 Depreciation and interest on house boat, fuel barges and other auxiliaries 600.00 Insurance on dredge and auxiliaries 528.00 Total miscellaneous and overhead $ 6,558.00 Total cost $25,000.81 Total material excavated, cu. yd 924,204 Cost per cu. yd $0.026 The material excavated was unusually well suited to the type of dredge used, being a light-weight muck over a soft clay. Oc- casional sand deposits were encountered, but these formed a very small percentage of the work. The kind of material accounts for the low cost. The measurements of material handled were taken in excavation. Operating charges were from actual cost records excepting the estimate shown on the last item. Wages were some- what lower than those paid in most Northern states. Oil was used for fuel until the cost came to $1.25 per bbl. delivered, when coal was substituted, at a cost of about $4 per ton. Dredge with Dragline Bucket. In 1904 a small dredge equipped with a derrick for handling a Page dragline scraper, was used to excavate compact glacial drift from under water, for filling a cofferdam at Green Lake, Wis. The material consisted of a light covering of sand overlying packed marl, clay, gravel and boulders. A centrifugal pump proved a complete failure, and an- orange-peel bucket brought up only 30 Ib. per trip. The scraper bucket handled 300 to 400 cu. yd. per day. The hull of the dredge was 42 x 28 x 2.5 ft. in size. The derrick had a 32-ft. mast and 95-ft. boom, both of 12 x 12-in. pine. The power equipment com- prised two engines and a boiler. Dipper Dredges. Engineering News, May 14, 1903, describes the dipper dredge as follows: A dipper dredge is really a scow-mounted steam shovel. The machinery is usually of larger size than that used for work on land, the dipper handle being very long and the dipper ranging in size from % to 15 cu. yd. This type of machine is best for general purposes. Dipper dredges are comparatively cheap and simple in construction, can do harder and heavier work than the other types of dredges, and can deal with stumps, roots, and other obstructions. Hard compact material such as glacial drifts can be dug because of the positive application of the power to the penetration of the bucket. In fact this type of dredge is the only one capable of handling very hard material such as cemented gravel and large pieces of blasted rock. The dipper dredge possesses one great advantage over the other METHODS AND COST OF DREDGING 687 088 HANDBOOK OF EARTH EXCAVATION kinds because of its " spuds." Spuds are legs of heavy timber (or, sometimes, steel) which are raised and lowered vertically, and when sunk into the mud provide a firm anchorage for the hull. The boat can manoeuvre on its spuds, using its dipper to pull itself into any desired position, and consequently it does not obstruct traffic with anchor lines. It can push its scows about with its dipper. While suited best to comparatively shal- low depths it can dig equally well to the full reach of its dipper or can cut barely enough to enable it to float. By changing the size of the dipper it can be readily converted from a hard material machine to a soft material machine. This is a most important consideration to contractors. The entire machine is under the control of one leverman and the necessary crew of one operator, one cranesman, 2 or 3 deckhands and a (i reman. Dipper dredges were formerly of the crane type but are now usually of the boom type. The average size of dippers generally used is about 6 cu. yd. The largest dredge of which the writers know is the " Onondaga " which has a 15-cu. yd. dipper, a hull 140 x 50 x 15 ft. in size, and which can excavate to a depth of 50 ft. The outputs of dipper dredges depend naturally upon many factors, chief of which are the size of the dredge, the depth being excavated, and the character of the material. On the Great Lakes a dredge equipped with 4.5 to 6-cu. yd. dipper excavated 4,450 cu. yd. in 10 hr. from depths of 20 ft. loading into scows. Conditions Favorable to the Dipper Dredge. The dipper type of gold dredge is suited to conditions where the ground is some- what shallow, where the extent of ground is not sufficient to war- rant a costly dredge, where the material is of somewhat rough character containing boulders and stumps and where the ground contains adhesive clay which is difficult to remove from elevator dredge buckets. Cost of a Dipper Dredge. The main dredge ditch of a swamp in Ha.rney County, Oregon, was approximately 24 ft. wide and 8 ft. deep, with banks sloping at 1 to 1. The work was located far from railroads and mills, lumber having to be hauled 60 miles, and it was therefore necessary to design a machine the materials and machinery for which could be conveyed economically. The ground was generally swampy, the material being namely a peat soil on a peaty, loam or clay sub-soil with pockets of cobbles and gravel. The machine determined upon for the work was a dip- per dredge with a 1^4-yd. dipper. This dredge had a hull of lumber 19x75x6 ft. in size. The boiler was a 50-hp. locomotive type boiler, and there were 2 engines, 10 x 12 in. in size, for operating the crane, and 7 small auxiliary engines for hoisting spuds, etc. The largest single METHODS AND COST OF DREDGING 680 000 HANDBOOK OF EARTH EXCAVATION piece was the boiler which weighed 7,000 11). The crane was han- dled in three parts of 2.67 tons each. About 2i/ months' time was required to construct the hull and barges. The cost of the plant was approximately as follows: Machinery and hull $ 9,750 Quarter-boat, 2 wooden scows, etc 4,900 Freight 2,100 Hauling , 1,200 Total cost of plant $17,950 The crew consisted of I engineman, 1 fireman, 2 deck hands, 1 cook and the necessary wood choppers and teams and drivers for supplying fuel. Sagebrush and dwarf juniper were used for fuel. The costs of obtaining both woods were approximately the same, but the labor required in firing the sage brush was twice that necessary for the juniper. The fetter wood had an efficiency greater than that of pine. Aligning a Dredge in a Canal. Engineering and Contracting, Feb. 13, 1907, gives the following: The following method of aligning a dipper dredge used in swamp reclamation work was employed with success. A permanent back-sight flag was set on the starboard water edge of the canal, and two permanent fore- sight flags were set at the end of the proposed tangent, one on the right and the other on the left of the proposed water edge. Two 3 x 12 in. planks extending out from the dredge were spiked to the port and star-board gunwales of the dredge to serve as gages. These planks were located directly opposite the runner's levers and were placed at right angles to the axis of the scow. A series of numbers was painted on the gages, the numbers be- in^ so arranged that the distance from any number on the star- board, gage to the corresponding number on the port gage equaled the required width of the canal at the water line. Before the day's dredging commences, the runner sets up a temporary flag back of the starboard gage, and in range with the starboard back and fore-sights. After each move of the dredge the runner goes out on the starboard gage until he comes into the back-sight range formed by the temporary flag. He then faces the other way and spots some natural object upon the forward cutting, in range with the forward starboard sight. After noticing the number that he is standing upon, he goes to the port gage and stands upon the number corresponding to the number on the starboard gage. After selecting some natural object upon the forward cut- ting range with the forward port sight he returns to the levers and cuts to these natural objects. Erection Costs of Steel Knock-Down Dredge. Engineering News, July 6, 1916, gives the following: METHODS AND COST OF DREDGING 691 A new design of steel dredge was recently brought out by the American Steel Dredge Co., of Fort Wayne, Ind. It is of the single-line type. The improvements pertain to the so-called struc- tural part of the dredge or the front end, embodying the dipper, dipper handle, boom and circle. Dippers in general use are of the square type, but the one on this dredge is made with an ex- ceptionally wide mouth and narrow back. The shell is formed of one piece of flanged steel riveted to the back casting, with a flanged-steel mouthpiece and lower band. The design of the dipper handle is unique and opens another field for acetylene welding. Dipper handles in common use are Fig. 5. Dipper Handle Formed of Two Rivetless Steel Boxes. of wood or of wood armored with steel plates on the four sides or are made of steel. In the latter instance they are usually built of I-beams reinforced to form a box section. The construc- tion of the new ' handle is a hollow-steel box section devoid of rivets. The box is formed by coping the flanges of two channels, so that when the latter are placed together they form a section of the proper width. The flanges are then welded for the entire length on both edges. Two of these box sectiens are required for each handle. The racks are bolted on in the same manner as on a wooden handle. The dipper-handle foot casting is put in place before the channels are welded, so that when this is done the channels contract, resulting in a tight fit on the casting. The dredge has a sectional hull, built entirely of flat steel sec- tions of convenient sizes for easy handling. A complete hull 80x20 ft. in plan by 6 ft. deep can be loaded on one flat-car. The tabulation that follows gives the cost of transporting and erecting one of the new machines. The figures were furnished the manufacturer by the contractor and are for one of the new dredges, equipped with a 1^-yd. dipper and 50-ft. boom, used on a large drainage district in Arkansas, 692 HANDBOOK OF EARTH EXCAVATION Fig. 6. " American " Steel Dredge with Bank Spuds. Transporting Steel Hull Hull weighing 88,000 lb., arrived on job. Oct. 22; hauled to bank on Oct. 23 and 24 60 man-hours @ 20 ct 110 man-hours @ 17y 2 ct 20 hours for foreman Two days' teaming Total transporting hull Erecting and Launching the Hull Erection began Oct. 26; completed Nov. 4 (work de- layed 1% days by hull grounding) 275 man-hours @ 20 ct 424 man-hours @ 17% ct 90 man-hours @ 12% ct Total erecting hull $ 55.00 74.20 11.25 $140.45 METHODS AND COST OF DREDGING Hauling Machinery Machinery arrived on two cars Oct. 29; hauled to dredge Oct. 30 to Nov. 4 50 man-hours @ 20 ct $ 10.00 110 man-hours @ 17 ct 18.70 30 hours for foreman 13.20 693 Total hauling machinery 41.90 Began Nov. 5; Installing Machinery completed Nov. 27 480 man-hours @ 20 ct ................................. $ 96.00 170 man-hours @ 12% ct .............................. 21.25 603 man-hours @ 17M> ct 105.52 Total installing machinery $222.77 Total cost of erecting dredge $464.17 Dredging with Steam-Shovel Mounted on a Hull. Engineering Neu-s, Jan. 18, 1917, gives the following: On canal clean-up work at Trenton, N. J., the Pennsyl\iania R. R. is using the machinery of a small revolving steam shovel mounted on a wooden hull. The boom and dipper handle are Fig. 7. How the Spuds on a Floating Shovel are Operated. especially long, making it possible to dig to a depth of 9 ft. be- low water and dump material 28 ft. from the centerline of the boat and 6 ft. above water. The hull is 40 x 18i/ ft. in plan by 4i ft. deep. The outfit is efficient for digging small ditches or for dredging shallow streams. It is cheaper to build than a reg- ular dredge for the same service and is cheaper to operate. The shovel used is of the Osgood 18 type. 694 HANDBOOK OF EARTH EXCAVATION The truck frame of the shovel axle and axle bearings re- moved is bolted to the hull. The heavy end-plate is bolted both to the shovel frame and (by means of an extension plate) to the hull. The special parts required to build this outfit are the spuds, spud machinery, backing drum at the foot of the boom, and the hull upon which the machinery is mounted. The general arrange- ment is shown in Fig. 7. To move the dredge forward: First, the dipper is placed far ahead; next, the hull is floated by raising the spuds; then, by starting the boom engines, the hull is caused to move toward the dipper. The spuds are then dropped, thus anchoring the hull, when the dredge is again ready to excavate. Costs of Dredgework on the Los Angeles Aqueduct. Engineer- ing and Contracting, May 31, 1911, gives the following: The costs of dredging are taken from the monthly report for February on a section of the Los Angeles aqueduct through the Owens Valley. The dredge consists of a scow on which is mounted a No. 60 Marion electric shovel with a iy 2 cu. yd. dipper. The cost of the dredge was $19,897 and was built according to the specifications of the aqueduct engineers. The yardage is based upon the theoretical section of the aqueduct or 14.81 cu. yd. per lin. ft. This is exceeded a small amount by excess cutting. The following are the data for February: Men number days 459 Live stock number days 68 Lineal feet t 2,625 Cubic yards 38,876 Labor costs $1,618.34 Live stock costs 61.20 Cost materials and supplies 122.07 Power cost 418.30 Freight cost 24.41 Total costs $2,244.32 Cost per cu. yd $0.0565 The cost per cu. yd. for the month figures 5.65 ct., but the unit cost given for the work of the dredge to date is 6.7 ct. A Steam Shovel Dredge. Engineering and Contracting, Dec. 25, 1907, gives the following: A steam shovel mounted upon a barge was used in securing gravel from the beds of streams for ballasting purposes. The gravel was obtained from streams which contained very little water during nine months of the year. The barge used cost about $1,000 and had a deck 20x50 ft. Upon this was securely mounted on a track a steam shovel weighing 78,000 Ib. and having a dipper capacity of 1^ cu. yd. The barge drew 2^ ft. of water. In excavating the gravel, the METHODS AND COST OF DREDGING 695 steam shovel was run forward on its track, the bow of the barge sinking and practically resting on the bottom, although for safety four 10 x 10-in. spuds at the corners of the barge were used to hold the barge stationary. The gravel was loaded into cars on a temporary track alongside the bank. When the gravel within reach of the dipper had been exhausted, the shovel was moved back on the track, the bow of the barge rising. The barge was then advanced and again secured by spuds. The cost of securing the gravel was about 4 ct. per cu. yd. Hydraulic Jet Equipment for Leveling Spoil Banks. Chester B. Loomis, in Engineering News, July 31, 1913, gives a descrip- tion of a dipper dredge built especially for cleaning a part of the channel for the Los Angeles River and for building levees. The special feature of the equipment was the hydraulic giant for level- ing the spoil banks. This dredge was equipped with a 1^-yd. bucket, x 55-ft. boom, and a dipper handle of such length as to enable it to dredge 10 ft. below the water surface. The hull was of steel 75 x 32 x 6 ft. in size, strongly braced longitudinally and transversely with bulkheads and braces. The hull proved very satisfactory and was lower -in cost than a wooden hull. It was erected and bolted together in the shop, the parts were then marked, dismantled and shipped knocked down by wagons. The entire hull was riveted together in 10 days by 8 men and 1 foreman. The standard equipment of this dredge comprised an 8 x 10-in. hoisting engine, a 6 x 7-in. swining engine, three 12-in. drums and spud hoists, and a boiler working at 125 Ib. pressure. In addi- tion to the regular machinery a second locomotive boiler and a compound duplex steam pump, 9}4 x 10 x 12 in. in size, were in- stalled. This pump supplied water to 2 hydraulic giants each mounted near the bow. The method of carrying out the work was as follows: Brush was cut in advance of the dredge and piled on each side of the line of the cut and about 10 ft. back from it. The channel being 80 ft. wide it was found more economical to have the day shift make a cut half the width of the channel, piling the material on one side of the brush. After making a cut and when the dredge was moved ahead for the next cut, the sluicing pump was started and a jet was played on the spoil bank. As the bank was di- rectly opposite the giant, the water jet was very effective and it was found that the bank could be cut down into a levee about 7 ft. high, with a top about 10 ft. wide, in about one-half the time it took to excavate it with the dipper. At the end of the day the dredge was moved back so that the night shift could start the dredge on the part yet unexcavated, the same method of sluicing 690 HANDBOOK OF EARTH EXCAVATION being employed. The spoil was largely sandy loam and silt with occasional clay and washed very easily. Stumps were washed back or buried by undermining. Water pressure at 30 to 35 Ib. per sq. in. was most elective. The Cost of Dipper Dredge. Engineering and Contracting, May 29, 1912, gives the following notes on the cost of dredging, ab- stracted from a report by B. F. Powell, Engineer for the Fort Lyon Canal Co., at Las Animas, Colo. The dredge was built under the supervision of the Marion Steam Shovel Co. Work on it was commenced April 3 and the hull was completed and launched on May 26, 1911. The boilers were steamed up on June 5 and used from that time on to furnish power for erecting the balance of the machinery. The fifteen-day test was begun on July 1, when it was demonstrated that the dredge would excavate its estimated yardage. The hull of the dredge is 100 x 41 x 8 ft. and required 135,000 ft. B. M. of lumber. It has two 120-hp. boilers, one double 10 x 12-in. hoisting engine, a double 8 x 10-in. swinging engine, an 80-ft. boom and a 2^-yd. bucket. The amount of work accomplished by the dredge in the soft material in which it worked, was: Cu. yd. July 74,000 August and September 130,000 October 71,750 Total ." "... 275,750 The cost of operation as given for the month .of October was 3.15 ct. per cu. yd. The dimensions of the irrigating and storage canal now being completed, are 120 ft. on top and 100 ft. on the bottom for the first two miles from the head gate; for the next mile the width is 20 ft. less and after the third mile the width is again reduced 20 ft., making the bottom width 60 ft., with 1:1 slopes. The depth is 10 ft. The cost of the dredge and operating expense for one season were : Materials : Dredge equipment $14,932.00 Extra boiler 1,600.00 Electric light plant 500.00 Freight 413.96 Tools 250.00 Extra machinery 571.17 Boiler flues 236.80 Oakum 4.50 Steel and castings 427.70 Wire rope 510.75 Oil 317.27 Coal and hauling 2,896.68 METHODS AND COST OF DREDGING 697 Hardware 1,880.22 Groceries and camp supplies 1,611.45 Lumber 5,033.27 Total materials $31,185.77 Labor : Constructor $ 584.70 Foreman 984.02 Cook 155.00 Dredge runner 722.83 Labor 1,717.03 Carpenters 1,232.05 Hauling 404.45 Sundry expenses, materials, teams, labor 2,818.33 Total labor $8,619.31 Total, labor and material $39,804.08 The above table shows the cost of the dredge, its construc- tion and its operation until the end of the season, Nov. 1, 1911, as shown by the company's books. If we multiply the yardage excavated by about 4 ct. (the cost of operation) and deduct this amount, $11,030, from the total shown in the table the result should give the cost of the dredge ready for operation. This is $28,774. Cost with Dipper Dredge on the Massena Canal. The cost of dredging on the Massena Canal is given by John Bogart in a paper read before the International Navigation Congress (see Eng. News,, Oct. 30, 1902). For excavating indurated clay and boulders that could not be handled by a centrifugal dredge nor an orange-peel dredge, a dipper dredge with a 2}-yd. dipper was used. This machine ex- cavated from depths as great as 20 ft., loading into scows. Two scows were employed, each having a capacity of 140 cu. yd. The dredge excavated an average of 754 ci*. yd. per 10-hr, day for 183 days. The loaded scows were towed during the day 5,500 ft. to the dumping grounds. The cost of the dredge, scows and tug was $43,000. In the tabulation following repairs and renewals are estimated at 10% per annum and interest at 4% per annum, the daily cost being figured on the basis of the actual number of days, 212, worked per year. The cost was as follows: Per day Labor, supervision, coal, supplies $30.56 Interest, repairs, renewals 28.80 Care during winter 1.00 Total daily $60.36 This is equal to a cost of 8 ct. per cu. yd. 698 HANDBOOK OF EARTH EXCAVATION A 1^-yd. dipper dredge worked one season, the unit cost of dredging being 8 ct. Dredging with a 6-cu. yd. dipper dredge also cost practically the same. It should be noted that dredges can not ordinarily be ex- pected to average 212 days worked each year. Cost with a Small Dipper Dredge, Florida. The cost of dredg- ing mud and sand at Manatee River, Florida, during August and September, 1887, is given by W. M. Black on p. 38 of " The United States Public Works." The depth dredged was 8 ft.; the depth of cut was 2 to 4 ft. The average distance to the dumping grounds was 3.5 mi. The plant employed consisted of 1 dipper dredge, 2 tugs, and dump-scows. The time occupied was 48 days, of which 25 days were worked. The working time was consumed as follows: Dredge working 100.1 hr. Dredge idle, waiting for tug 89.5 " Dredge idle, repairing machinery 3.2 ' Dredge idle, shifting and moving 57.5 ' Dredge idle, pumping scows 17.2 " 25 days at 10.7 hr. each 267.5 hr. The total amount dredged was 15,302 cu. yd., the amount dredged per working day being 612 cu. yd. Dredge: 48 working days Per cu. yd. Captain at $125 per month, plus $15 board $0.015 Engineman at $60 per month 0.008 Crew of 7 men at $30 per month 0.033 Tug: 48 working days Captain at $90 per month, plus $15 board 0.011 Engineman at $60 per month 0.008 2 firemen at $30 per month 0.010 2 deck hands at $30 per month 0.010 Tug: 28 working days Captain at $90 per month 0.006 2 enginemen at $60 per month 0.009 2 firemen at $30 per month 0.005 2 deck hands at $30 per month 0.005 Materials : Wood for dredge, 7 cords daily at $3 for 31 days 0.043 Wood for tug, 4 cords daily at $3 for 37 days 0.029 Wood -for tug, 5 cords daily at $3 for 24 days 0.024 5 guide piles at $5. Dredge, interest, depreciation and repairs 0.106 Tug, interest, depreciation and repairs 0.011 Tug, interest, depreciation and repairs 0.008 Total per cu. yd $0.341 Dredging a Canal on the Florida Coast. George P. Miles gives a description in Engineering News, Apr. 25, 1904, of the methods METHODS AND COST OF DREDGING 699 used in excavating canals that connected lagoons along the Florida coast. At first elevator bucket dredges were used, but these were soon abandoned, owing to the constant wear on the links connecting the buckets. In a personal letter to the author, Mr. Miles states that the Florida sand cut the links of the bucket- ladder so rapidly as to cause numerous delays. Furthermore, the cost of repairing dredges in Florida is larger than in a country where machine shops and manufacturing facilities are at hand. Although duplicate parts were kept in stock, the repair costs were very high, as will be seen in the statement of operation expenses given later. Clamshell, suction and dipper dredges were also tried, the last two being most effective. Osgood dipper dredges for hard ground and suction dredges for shoals of recent formation were found most efficient. In dredging soft mud with dippers the mud would slide so badly that it was found necessary to attach a long chute to the A-frame of the dredger, and to dump into the chute. The ma- terial would spread over the adjacent marshes in a thin layer. Dredges on the Chicago Canal. The material on Sections of the Chicago canal was excavated mainly by steam dipper dredges, loading into scows that were towed out to Lake Michigan and there dumped. A description of the work is given by Mr. Alex. E. Kastl in Journal, Association of Engineering Societies, vol. 14, April, 1895, from which the following data have been abstracted: The largest number of dredges employed at any one time was five, of which four worked steadily from May 15 to December 27, 1894. During this period 400,262 cu. yd. were dredged; the average output per 10-hr, shift per dredge was 606 cu. yd., and the average scow load was 184 cu. yd. The largest average out- put per 10-hr, shift per dredge in any month was 870 eu. yd., and the least was 330 cu. yd.; the latter low output being due to the fact that the dredges were mainly engaged in finishing the bot- tom and the side slopes. The largest average scow load was 230 cu. yd., and the least was 140. The largest amount excavated by any one dredge in 10 hr. was 1,800 cu. yd. The dredges varied in size, but all had hulls about 90 x 32 x 9 ft., 2^ to 3^-cu. yd. dippers, and burned 2y 2 to 3^ tons of coal per 10 hr. 10-yd. Dredges on the Cape Cod Canal, Mass. Two very power- ful dredges constructed for excavating the Cape Cod Canal during 1912 are described in Engineer-ing News, Feb. 19, 1914 These machines were 10-cu. yd. dipper dredges. The hulls were of steel, 135 ft. long, 42 ft. beam, and 10 to 12 ft. deep. The crowding engine was a 12xl5-in double cylinder, and the main engine an 18-x 24-in. double cylinder engine. The dipper handles were 70 ft. long, enabling the dredge to dig in 40 ft. of water. 700 HANDBOOK OF EARTH EXCAVATION The dredges began excavation Sept. 1, 1912. Slight progress was made during the fall, the working out of defective parts caus- ing frequent stoppage. In January, 1913, the excavation of the two dredges amounted to about 32,000 cu. yd. per dredge per month. The dredges were subjected to two months of repairs and changes, were returned to the Canal in March, 1913, and began working continuously three 8-hr, shifts per day. Each then averaged very nearly 100,000 cu. yd. place measure per month. In June and July, 1913, the " Governor Herrick " exca- vated 120,000 and 131,000 cu. yd. place measure. The season's performance by the " Governor Warfield " was more uniform. The output increased from 50,000 cu. yd. per month to 110,000 cu. yd. in July, and was maintained at a rate of 120,000 cu. yd. per month throughout August and September, 1913. The material was sand. Cost of Dredging on the N. Y. Barge Canal. A description of some performances of dipper dredges on the New York State Barge Canal is given by Emile Low in Engineering and Contract- ing, Apr. 29, 1914. The contract in general provided but one price for all excava- tion, a lump sum for each cubic yard of material excavated of every name and nature; and no attempt was made to classify the materials excavated. Contract No. 19 is prism excavation in Tonawanda Creek. This included about 2,842,000 cu. yd. of sand, gravel, clay, etc., which was let at the contract price of 17.5 ct. Among the vari- ous machines working on this contract was a dipper dredge, the "Buffalo," with a hull 86 ft. long, 29.5 ft. wide, arid 8 ft. high. This hull was constructed of the best grade of long-leaf, yellow pine. The main engine was a 12.5 by 15-irx, double cylinder. The swinging engine was a 10 by 10-in., double cylinder. The boiler was of the Scotch marine type, 8.3 ft. in diameter and 10 ft. long. The pinning up engine was 7% by 7-in., double cylinder. The dredge was equipped with a 2.5-cu. yd. hard-dig- ging dipper, and a 3.25-cu. yd. soft-digging dipper. It could excavate to a depth of 23 ft. below water. The cost of the machine was about $35,000. The work of the dipper dredge at the start was mainly exca- vation of the prism, the material being deposited in dump scows, towed to points near the shore, dumped and redredged by two clam-shell dredges, with booms of 80 and 100 ft. respectively, the dumped material being then rehandled into spoil banks. Later on the dipper dredge was rebuilt and was used to dredge the hard material, encountered on the bottom of the prism, which in time verged close to hard sand. This hard material was METHODS AND COST OF DREDGING 701 dumped in various places along the creek, and was later handled by the hydraulic dredge " Niagara." The following tabulations show the output of the dipper dredge for a number of years: Year Cu. yd. 1908 132,687 1909 28,100 1910 81,873 1911 ' 30,500 1912 168,192 Total 441,352 The following gives the month cost of labor for running the dredge for a double shift of 16 hours: 1 captain $ ! 5 Z- 5 9 1 runner 2 cranemen at $106.50 2 oilers at $77.50 2 firemen at $77.50 4 deckhands at $67.50 4 scowmen at $67.50 1 watchman 1 blacksmith Total monthly cost $1,493.00 As the average monthly output of the dredge was only about 10,000 cu. yd., and as the contract price was 17.5 ct., amounting to about $1,750 per month, it is apparent that this price barely covered the expense of wages and coal. Blasting a Pit for a Dipper Dredge. F. W. Wilson, in En- gineering News, gives the following: Two large ditches were to be dug in New Madrid .County, Missouri. The contractor owned two dipper dredges, but there was no basin in which to float a dredge in order to start the ditching. A pit was required 136 x 50 x 6 ft. deep. It was decided that this could be formed quickest by blasting. The hole was shot by a professional dynamiter. Bore holes were put down, running the length of the proposed pit, in eleven parallel rows 3 ft. apart. The holes in the middle row were each loaded with 2y 2 Ib. of dynamite. The holes in the two rows on either side of the middle line were spaced 15 in. apart in the row and each loaded with 2 Ib. of dynamite; the holes in the next two rows were loaded and spaced the same way. The spacing between holes in the next two rows was 2,y 2 ft. and the loading iy 2 Ib. per hole; in the next two rows the holes were 2 ft. apart, and each was loaded with 1 Ib. The holes in the two outsida rows were spaced 18 in. apart and loaded with y 2 lb- each. In all, 950 Ib. of dynamite was used. The result of the shot was a pit 43 ft. wide, 136 ft. long and 7 ft. deep in the center, with an average depth of 3^ ft., with 702 HANDBOOK OF EARTH EXCAVATION the exception of one spot where a large cypress stump had stood and which caused the dirt to pile up. The blaster claims that he did not want to blast the pit in one shot, but the contractor wanted it done that way and so he acquiesced. The blaster's idea was to blast out two pits and then shoot out the division. By this method much less earth would have fallen back into the excavation. Operation of 15-yd. Dredges on the Isthmian Canal. Engineer- ing and Contracting, Oct. 17, 1917, gives the following: In the early part of 1914 the Isthmian Canal Commission began operat- ing two 15-cu. yd. dipper dredges on the completion of the chan- nel through the Gaillard Cut of the Panama Canal. These dredges the Gamboa and Paraiso were built by the Bucyrus Co., the total cost including the towing to the Isthmus, being $573,287. The dredges operated so efficiently that the Commis- sion placed another contract with the BUcyrus Co. for a third dredge, of improved design, the Cascadas. The dredge was placed at work in Gaillard Cut on Oct. 31, 1915, at a total cost of $376,180. An interesting study of the design, operation and efficiency of these dredges was given by Mr. Ray W. Berdeau in a paper presented Sept. 19, before the American Society of Civil Engineers, from which the matter in this article is abstracted. The following are the principal dimensions, etc., of the Gam- boa and Paraiso: Length of hull 144 ft. in. Beam, moulded 44 ft. in. Depth, moulded 13 ft. 6 in. Draft 8 ft. in. Digging depth, below water line 50 ft. in. Displacement 1,730 tons One main engine, two cylinders, compound, 16 by 28 by 24 in. One swinging engine, two cylinders, compound, 12 by 16 in. One backing engine, two cylinders, compound, 12 by 16 in. Two forward spud engines, two cylinders, compound, 12 by 16 in. One stern spud engine, two cylinders, 9 by 9 in. Two deck winches, two cylinders, 6 by 6 in. Two boilers, Scotch marine type, 126 in. diameter, 138 in. long, water pres- sure, 150 Ib. Two forward spuds, 48 by 48 in., and 82 ft. long. One stern spud, 30 by 30 in., and 83 ft. 6 in. long. Swing circle, 24 ft. in diameter. Bail pull, 235,000 Ib. Hoisting pull on spud rope due to engine, 88,000 Ib. " Pin up " pull on single cable, with brake on engine, 160,000 Ib. Capacity of rock dipper, 10 cu. yd. Capacity of mud dipper, 15 cu. yd. Capacity of fuel oil tanks, 14,200 gal. The displacement of the Cascadas is 2,095 tons, and the hull is 144 ft. long, 55 ft. beam, and 15^ ft. deep. Thus, it is 11 ft. wider than the others, making less reactions on the spuds, less METHODS AND COST OF DREDGING 703 metacentric variation when digging over the sides, and it allows the spuds to be inset. The spud-well construction differs from that of the Gamboa and Paraiso, as their forward spuds are placed outside the hull, with tapering sponsons fore and aft to transmit the reactions to the sides of the hull. The dredges were supplied with interchangeable buckets of two sizes, one with a capacity of 15 cu. yd. and another of 10 cu. yd., for use in rock excavation. Having been placed in Gaillard Cut in rock digging exclusively, the larger dippers have been seldom used; the smaller ones, as supplied by the con- tractors, were of extra massive construction, but were of insuffi- cient strength to withstand the severe use and the impact from a dipper stick load of 131,000 lb., and were replaced later by the Missabe type of cast manganese-steel dippers. The over-all dimensions of the new dipper are Wy 2 by 9 by 9 ft.; the lips are 314 in. thick at the bottom bands, and the body consists of a iront and back casting with lap-riveted joints at the sides; and, in addition, the lip is a separate casting riveted to the front piece and joined thereto by the rivets of the tooth ribs. All three dredges have been working until recently in Gaillard Cut of the Panama Canal. The material excavated consisted of hard and soft rock, to depth of from 35 to 47 ft. The accom- panying costs include operation, that is, wages of crew, subsist- ence of crew, fuel and lubricants, maintenance, that is, the cost of keeping the equipment in first-class physical condition, and maintenance only. Extra heavy 10-yd. manganese-steel dippers were used on this work, the dredges working continuously in three 8-hr, shifts. YARDAGE EXCAVATED BY FISCAL YEARS July 1, 1913, to July 1, 1914 Cu. yd. Per cu. yd. Gamboa 1,825,122 $0.1278 Paraiso 69,812 0.2931 Cascadas , . July 1, 1914, to July 1, 1915 Cu. yd. Per cu. yd. Gamboa 1,825,1^2 $0.1278 Paraiso 1,739,228 0.1313 Cascadas July 1, 1915, to July 1, 1916 Cu. yd. Per cu. yd. Gamboa 3,097,226 $0.0731 Paraiso 3,004,104 0.0769 Cascadas 2,400,492 0.0651 July 1, 1916, to Oct. 1, 1916 Cu. yd. Per cu. yd. Gamboa 599,575 $0.0713 Paraiso 818,095 0.0658 Cascadas 666,656 0.0742 704 HANDBOOK OF EARTH EXCAVATION World's Dredging Record at Culebra. According to 'Engineer- ing and Contracting, May 3, 1916, from midnight to midnight on Feb. 18, 1916, the 15-cu. yd. dipper dredge " Cascadas," work- ing in Gaillard (Culebra) Cut, Panama Canal, excavated 23,305 cu. yd. of rock and earth. This is believed to be the world's record. The actual working time of the " Cascadas " having been 23 hr. and 15 min. during the record day, the rate of output was slightly over 1,002 cu. yd. an hr. This is about 1,500 tons an hr. or 25 tons a min. The " Cascadas " was built by the Bucyrus Co., South Milwaukee, Wis., and of her record the Canal Record says: The 15-yd. dipper dredge, "Cascadas," was placed in com- mission on Oct. 31, 1915, and was in the cut continuously until March 20, when she was brought to the repair dock at Paraiso for renewing the starboard spud. During that time, slightly over 4^ months, the " Cascadas " excavated 1,447,946 cu. yd. and was delayed by breakdowns 77 hr. and 35 min. Her average excava- tion was 466 cu. yd. per hr., over a working period of 3,104 hr. The dredge was engaged throughout in excavating rock. The loss of time from breakdowns was only 2.44% of the total work- ing time. Ladder Dredges. Ladder Dredges are known as bucket-elevator dredges, chain-bucket dredges, endless-bucket dredges, conveyor- , bucket dredges, etc. This type of dredge is a favorite abroad, but in America it is confined mainly to. canal work and to gold dredging. The comparatively rare use of this type of machine is due to the relatively high first-cost and the larger crew re- quired, as well as the fact that other types of dredges are suited to work of more widely varying nature. The introduction of special steels has reduced the wear on such working parts as chains and buckets, to a large extent, making this type of dredge one of the most efficient for work of large extent, except where the material is of an extremely abrasive nature. (See the fore part of this chapter for a description of the difficulties en- countered wfien using elevator dredges in Florida.) As the name of this dredge implies, it has an endless chain of buckets which cut into and scoop up the material, and elevate it to the top of the ladder on which the line of buckets travels. There the material is delivered to an inclined chute or a travelling belt conveyor. The earliest forms of these dredges had chutes inclined 1 in 10 for clay and 1 in 20 for fine sand, but long chutes became clogged. On the earlier work on the Panama Canal auxiliary jets of water had to be provided to keep the chutes clean. Wet clay will slide down chute inclined 1 in 5 to 1 in 3, if the material is comparatively free from sand. Wet METHODS AND COST OF DREDGING 705 sand will not slide down an incline of even 1 in 2 without a free flow of water. According to J. J. Webster, when the volume of solid is diluted with 2 or 3 times its volume of water, the best angles for chutes are as follows: for soft mud 1 in 10; for soft clay 1 in 12 to 16; for fine sand and water 1 in 25. On the Suez Canal work it was found that when fine sand was mixed with equal quantities of water it would flow down a slope in 1 in 25. The modern bucket-elevator dredge has an endless belt conveyor instead of an inclined chute, which reduces the height to which the material must be raised and delivers it with the certainty of not becoming clogged. The output of a bucket-elevator dredge depends on the capa- city, and quantity of the buckets, the mode of power transmis- sion from the engine to the dredging apparatus, the size of dredge, as well as the methods of operating and the local con- ditions such as the character of the soil. Mr. J. J. Webster in 1887 read a paper before the Institute of Civil Engineers (England) in which the gave the following formula, based upon actual tests. Hp.= 0.04TVH for stiff clay; hp.= 0.026 T V H for soft mud; hp. being the indicated horsepower required to excavate and raise T tons per hr. to a height of H ft. Where T = 450 and H = 40, he found hp.= 98 in one case, or 1 hp. excavated nearly 4.5 tons per hr. In the Transactions of the American Society of Mechanical Engineers, 1886-7, A. W. Robinson, the well-known designer of dredges, gives a paper on bucket elevator dredges in which he says that certain indicator cards showed that 1 hp. would excavate 5 to 9 cu. yd. per hr. on a bucket elevator dredge, both working in the same kind of tolerably yielding material in water 32 ft. deep. If we assume a total lift of 40 ft. 1 hp. should raise 16i cu. yd. (3,000 Ib. per cu. yd.) of earth per hr., if there were no loss in friction of machinery,' no dead weight of buckets and water to lift and no force consumed in loosening the material. The bucket elevator dredge is used almost exclusively where gold bearing gravel is excavated. It is claimed that the dipper dredge stirs up the gravel to such an extent that the gold settles and escapes; and further losses of gold occur through the cracks between the door of the dipper and the sides of the dipper. The writer is not inclined to accept this theory of gold loss, but it is desirable to have a dredge like the bucket elevator that delivers a steady stream of gravel instead of an intermittent stream. Dredging Silt Bars, Muscle Shoals Canal. A paper by A. D. 706 HANDBOOK OF EARTH EXCAVATION Edwards appearing in Professional Memoirs for January-Febru- ary, 1912, is quoted by Engineering and Contracting, Jan. 17. 1912. The Muscle Shoals Canal is divided into two parts, locally designated as the upper and lower divisions, which are separated by 8 miles of open river. The upper division consists of two locks connected by a mile of canal, an upper pool 2}fc miles long, and a dredged channel below the lower lock. The lower division is composed of 14^ miles of canal and nine locks. Fifteen streams varying in size, empty directly into the canal. Though none of them is very large, yet at every freshet they bring down sediment, and bars are constantly forming in the channel oppo- site their mouths. At the entrance to both divisions of the canal a large amount of silt also accumulates at every high water, and constant dredging is therefore required to keep it cleaned. A Bucyrus dredge of the elevator type is employed on the canal for this purpose, having the following general dimensions: Length, 80 ft., width in center, 38 ft.; width at each end, 13 ft.; depth of hull, 6 ft. The sides are circular, being struck with a 68-ft. radius so as to give the above dimensions. Draft when working, 42 in. A chain of 24 buckets and 24 links is mounted on a ladder frame 48 ft. long, equipped with truss rods and fittings, rollers with shafts arid bearings, top and bottom tumblers, device for holding bucket chain, and hoisting tackle for regulating the depth of cut. This chain of buckets works over the forward end of the boat, and slops back at an angle of 45 until it reaches an elevation of about 22 ft. above the deck, where the material is discharged into a hopper. This chain of 24 buckets, each having a capacity of 5 cu. ft., makes one complete revolution in 1}4 min., discharging 4.44 cu. yd. per revolution, which gives the dredge a capacity of 213 cu. yd. per hr., or 2,130 cu. yd. per day of 10 hr. From the hopper, which is located 15 ft. above the center of the boat, a discharge pipe 26 in. in diameter and 80 ft. long, suspended by a set of tackle attached to an A-frame, conducts the material that is dumped into the hopper to the place of deposit, which is usually beyond the tow-path. When the material is thick and heavy, a stream from a 6-in. pump is turned into the pipe to keep it flushed out. The dredge is equipped with a 10 x 14-in. double cylinder en- gine making 140 revolutions per min., developing 40 hp. The swinging engines are double cylinder, 8-in. diameter and 8-in. stroke. The boiler is of marine type, 40 hp., 60 in. in diameter, 17 ft. long, and carries a pressure of 90 Ib. For flushing the discharge pipe a Gordon Duplex steam pump is used, having 12-in. METHODS AND COST OF DREDGING 707 steam cylinders, 10-in. plungers, and 16-in. stroke; capacity, 326 gal. per min. This dredge, when in operation, revolves about a center spud, which is 40 ft. from the point of the buckets, thus enabling a cut 80 ft. wide to be made. The depth of the cut varies from 3^ to 10 ft. below the surface of the water. This dredge has an advantage over other types, as it cleans the entire widtli of the canal as it moves forward, and deposits the material outside of the canal bank, where it does not have to be handled again. The canal is cleaned with a single cut, with the exception of a few places where two cuts, and some- times three, have to be made before the material is finally de- posed outside the canal bank. This method is a little slow, but it is the best way to handle the work, as it would not be prac- ticable to load the material in scows and tow them outside of the canal. Above Lock A (upper division) three cuts have to be made, and- between Locks 1 and 2 (lower division) three cuts are necessary. Another point where some difficulty is ex- perienced in operating the dredge is above Lock 1, where the banks are too high for the discharge pipe to reach over them. To dredge this part of the canal the river has to be caught at a stage that will allow the discharge pipe to clear the bank. The crew necessary to operate the dredge consists of one dredge runner, one engineman, one fireman, one spudman, and two linemen. The hull of this dredge was built at Chattanooga, Tenn., by contract, in 1891. The machinery. was placed on the hull and floated to the canal, where the cabin was built and machinery installed. The total cost of the dredge was approximately $20,- 000. The hull was rebuilt at the canal by hired labor in 1902 and 1903, at a cost of $10,000, being put back in commission in October, 1903. The dredge has been operated almost continu- ously since it was rebuilt. A new hull will have to be built within the next year or two, also a complete set of new buckets and links will be required. The machinery is in good condition and will outlast another hull. The following statement gives the number of cu. yd. dredged with cost of labor, material, and field repairs since the dredge was put in commission. Year Ou.yd. Per cu.yd. 1892 27,210 1893 38,964 1894 42,800 1895 13,235 1896 5,513 127,722 $0.036 708 HANDBOOK OF EARTH EXCAVATION Year Cu. yd. Per cu. yd. 1897 61,550 .039 1898 62,097 .041 1899 39,375 .036 1900 59,200 .038 1901 18,093 .144 1902 55,764 .031 1903 38,123 .028 1904 100,012 .030 1905 105,490 .031 1906 146,968 .030 1907 111,337 .023 1908 59,372 .056 1909 117,777 .046 1910 195,982 .036 *1911 87,731 .036 1,386,593 $0.036 Total cost of labor, material and field repairs $51,302 Cost of rebuilding hull in 1902 and 1903 10,000 Deterioration of plant 10,000 Total cost of dredging since 1892 $71,302 *To Jan. 1. 1911, of fiscal year ending June 30, 1911. This gives for the unit cost of dredging 1,386,593 cu. yd. of ma- terial, 5.11 ct. per cu. yd. Trestle Filling with a Ladder Dredge. Engineering News, Aug. 4, 1892, gives the following: Near New Orleans, La., a railway trestle 18 miles long and 7 to 10 ft. above the ground and water level, was filled with material obtained by excavating a canal alongside and 50 ft. away. A bucket elevator dredge with a hull 40 ft. wide, 40 ft. long, and 6 ft. deep, equipped with a 90-ft. belt conveyor, was employed. This machine excavated 472,- 934 cu. yd., or 34,170 lin. ft. of cut 6 ft. deep by 60 ft. wide, from Jan. 1, 1891 to April 30, 1892, an average of 2,135 lin. ft. or 29,558 cu. yd. per month, or 1,180 cu. yd. per day, measured in cut. A 10-hr, day was worked, but passing trains reduced the actual working time to 7 hr. per day. Many sunken logs and cypress roots were encountered and material retarded the work. The dredge required a crew of 6 men. Excavation cost about 3 ct. per cu. yd. It is interesting to note that in this material the original rubber conveyor belt was still in service after having conveyed 473,000 cu. yd. High Cost of Dredging at Havana, Cuba. A. H. Weber, in Engineering Record, Nov. 23, 1901, gives some cost data of dredging at Havana. A bucket-ladder dredge with a " capacity " of 1,000 cu. yd. in ordinary harbor mud, but only 200 to 600 cu. yd. in hard clay, was used. In addition t^o small clamshell dredges, of the Prestmann type, with %-cu. yd. bucket, and " ca- METHODS AND COST OF DREDGING 709 pacity " each of 200 to 400 cu. yd. in mud, were worked. These machines were not at all effective in hard clay. Rock and very hard clay were encountered, and had to be blasted. An Ingersoll auto-feed 4%-in. cylinder drill was hung in the leads of a floating pile driver. This machine drilled through a telescopic tube from 4 to 12 in. in diameter. The charges were loaded in the holes by a diver. At first 10 holes spaced 5 ft. apart in a row were blasted to the requisite depths of 12 to 16 ft., but it was claimed that the charges injured adjacent buildings. The holes therefore, were drilled only 6 to 8 ft. deep and charged with 6 Ib. of 60% dynamite each. The whole area, therefore, was removed in two or three lifts. The number of holes drilled was 1,682, and 5,600 Ib. of dynamite were used. If the clay was allowed to remain undredged after being blasted, it would become hard and require reblasting. The total amount of material dredged measured 47,970 cu. yd. scow measure, of which about 10,500 cu. yd. were stone. The unit cost of stone excavation exceeded that of the clay by about 75%. The total cost of the work was $35,734. Per cu. yd. ct. Dredging, wages, supplies and repairs 49.2 Dredging, wages, supplies and repairs 12.3 Explosives 2.8 Moving scows to sea 3 miles 7.6 Office operation and superintendent 2.6 Total per cu. yd 74.5 The work was done by day labor for the government. A Ladder Dredge with a Belt Conveyor System. In Engineer- ing News, Oct. 25, 1906, I, M. Mann gives the following: On the Fox River, Wisconsin, dredging over a period of 50 years by dipper and clam-shell dredges had formed high spoil banks on each side of the channel. These were unsightly, objectionable to property owners, and were subject to erosion' by the current, necessitating a second and third dredging of about 25% of the material. To overcome this objectionable practice, a dredge was designed to fulfill the following conditions: ( 1 ) Ability to dig all materials except solid rock or equally hard material; (2) Ability to cut full width of channel without moving the dredge sideways; (3) Ability to convey the spoil a considerable distance with- out rehandling; (4) Ability to obtain the greatest possible area of distribution of spoil and to deposit either side of the channel and in low places or scows; 710 HANDBOOK OF EARTH EXCAVATION (5) Ability to carry the spoil in places over old dredge banks not less than 20 ft. in height and to distribute it without form- ing new banks. These conditions were fulfilled by the " conveyor dredge." This plant consists of a dredge with two intermediate conveyor scows and one delivery scow. The delivery scow can be attached directly to the dredge if desired. The dredge is of the regular bucket-elevator type, having 30 buckets of 5 cu. ft. capacity each, equipped with steel cutting teeth. It is able to dig to a depth of 10 ft. The dredge hull is of fir, 75x31x6 ft. in size. It is equipped with a 9 x 12-in. and a 6 x 6-in. engine, a 35-kw. electric generator, and electric motors. Steam is supplied by a marine boiler 10 ft. long. The intermediate scows are 40 x 15 x 3 ft. in size, and each carries a belt conveyor 32 in. wide and 65 ft. long, driven by electric motors. The delivery scow is nearly triangular in shape, being 31 ft. long and 16 ft. wide at the delivery end. It is furnished with a delivery belt conveyor supported by a derrick, and overhanging the stern by about 40 ft. The delivery end of this conveyor can be raised to 20 ft. above water to suit the height of the spoil bank. The total length of the outfit is 300 ft. The dredge is furnished with a turning spud at the stern amidships, and a walking spud slightly forward and to starboard. It is moored to shore anchors by bow lines, and digs in a circle of about 80 ft. radius, covering a width of channel of 145 ft. In operation the material leaving the elevator buckets at the top of the ladder passes into a hopper, thence to a belt conveyor that carries it to the stern of the dredge, thence to another hopper, and finally, by the various conveyors on the scows, to the shore. The crew consisted in 1906 of 9 men. The cost of operation, including fuel, was $30 per day. In ordinary digging the dredge excavated 400 cu. yd. per hr. in a trial test, and in very tough clay and hard pan 200 cu. yd. per hr. Bucket-Ladder Dredge with Long Chutes. In a paper in the Proceedings of the Institute of Civil Engineers (Great Britain), John B. Body gives a description of the drainage of the Valley of Mexico. His paper is quoted in Engineering Record, Aug. 10, 1901. Part of the work was excavated by Indians, who carried bas- kets on their heads, and part by a grab-bucket on a cableway. The main part of the canal, however, was dredged with 5 " couloir " or long-chute dredge of the bucket-ladder type. These machines had main engines of 150 hp. One of these dredges was of large size with the top tumbler of the bucket-ladder at a METHODS AND COST OF DREDGING 711 height of 74.5 ft., while the other four had top tumblers at a height of 56 ft. The material was discharged from the bucket- ladder on to the chutes. These extended 165 ft. from the center of the dredge over the bank of the canal. Pumps, discharging as much as 600 cu. ft. of water per min., facilitated the passage of the dredged material through these chutes. At times the material was discharged as far as 185 ft. from the center of the dredge. The ladders were 78 ffc long, and the buckets had capacities of 11 cu. ft. each. In very sticky soil, hinged bottoms were used on the buckets with exceptional success. The maximum depth excavated was 63.5 ft. in 48 months, and 8,500,000 cu. yd. were dredged. The best output of a single dredge for one month, working day and night, in soft soil, was 124,230 cu. yd. In hard soil a fair average was 90 cu. yd. per hr. The most suitable face against which to work was 6 ft. in height. Ladder Dredge and Conveyor on N. Y. Barge Canal. Engineer- ing and Contracting, Sept. 7, 1910, gives the following: The dredge was started on July 30, 1909, and worked 4 months of the season and was then laid up for the winter, as the canal is drained during the winter season. The costs given are for thess 4 months' work. This dredging plant differs from other types in that the excavated material is carried by a series of belt con- veyors to the spoil bank. The dredge itself is floated on two steel pontoons which are parallel to each other and are braced together by a rigid frame work. A gantry projects out in front and between these pontoons. This gantry supports the " ladder " or endless chain of buckets, which extends down between the pontoons to the bottom of the canal. The buckets move down- ward on the underside of the ladder and come up loaded and discharge into a hopper at the top. The buckets are each of 5 cu. ft. capacity. From the hopper at the top of the ladder the material is discharged onto a belt which hi turn discharges into a second hopper and second belt at the rear of the dredge which projects out to the rear of the machine. A third belt is carried on a separate pontoon. It runs on a steel cantilever framework which carries the belt 40 or 50 ft. onto the canal bank. The pontoon which carries this belt is so arranged that it can be turned at any angle and still have its receiving hopper under the discharge of the second dredge belt. The belts are each operated by a separate motor receiving power from the dredge. The dredge plant cost $70,000. The plant took out from 20,000 to 32,000 cu. yd. per month during the first few months it was in operation in 1909, working three 8-hr, shifts per day. The chief difficulty met with in the first part of the work was 712 HANDBOOK OF EARTH EXCAVATION holding the soft material in embankment. At first very heavy wooden forms were built to hold up the embankment to its full height. These proved very expensive and inefficient; they gave way in places and the soft material, which flowed out over the adjacent land, had to be scraped back. The plan now adopted is to build dikes of sod and earth about 4 ft. high along the outside edge of the embankment. The material is then deposited by the dredge within the dikes, the dredge moving along as soon as the material reaches the top of the dikes. When the material deposited has dried out sufficiently, a second series of dikes is built on top of the first and the dredge moved back to fill again. The cost of the work for one season is given by months as follows : August, 1909; 18,638 cu. yd. excavated: Coal and oil $1,984.50 15 tons coal for hoisting engine at $2.85 42.75 Misc. supplies for hoisting engine 5.25 Misc. supplies for hoisting engine and derrick 6.48 Hauling supplies 54.00 Crew of dredge 2,296.68 Total cost $4,389.66 Cost per cu. yd. (ct.) 23.6 Drains and scrapers supplemented the dredge moving 6,244 yd. for a total of $1,280.50 or 20.5 ct. per cu. yd. The cost of wooden forms and of spreading and compacting amounted to $1,193 for 10,015 cu. yd. of embankment or 11.9 ct. per cu. yd. September, 1909; 32,000 cu. yd. excavated: Interest, depreciation and repairs $2,205.00 180. tons at (2 tons per shift) 513.00 150 gal. gasoline at 12 ct 48.00 Oil (80 gal. at 19 ct. ; 60 gal. at 35 ct.) 36.20 1,200 Ib. grease at 8 ct 96.00 200 Ib. waste at 8 ct 16.00 Teams 245.00 Labor 2,827.00 Total cost $5,956.20 Cost per cu. yd. (ct.) , 18.6 A total of 90 (8-hr) shifts were worked. The cost of the em- Lankment was as follows: Labor spreading and compacting $3,151.50 Hauling form lumber 177.16 Cost form lumber 1,125.00 General ,. 290.00 Labor on forms ". 828.32 Hauling supplies 55.00 Total . . $5,626.98 METHODS AND COST OF DREDGING 713 Only 11,000 cu. yd. were allowed for the above work on em- bankment as the forms gave way and the soft material had to be scraped back. This brought the cost of embankment for the month up to 51.1 ct. per yd. October, 1909; 25,500 cu. yd. excavated: Interest and depreciation \. $2.351.66 186 tons coal at $2.85 530.10 Labor 3,145.58 Teams 5.00 Oil, 'grease and waste 153.09 Gasoline 18.60 Repairs 18.90 Total cost $6,222.93 Cost per cu. yd. (ct.) 24.4 A total of 93 (8-hr.) shifts were worked. The cost of em- bankments was as follows : Labor spreading and compacting ' V 2,898.25 Forms 567.50 Erection * 108.50 Hauling , 95.00 Total $3,669.25 This gives for 21,800 cu. yd. of embankment a cost of 16.9 ct. per cu. yd. Thomas J. Morrison objected that the cost shown for embank- ment in the foregoing paragraph was deceptive. It should be accompanied by an explanation, showing why it was so high. The embankment forms to hold the dredge material were very expensive, and the cost was charged up to the embankment on * which they were built. Under the specifications, the embank- ment could not be estimated as paid for until finished; and the paid embankment was therefore only a small part of the exca- vations among which costs are given. For instance in November, the excavation was 20,560 cu. yd., of which only 513 cu. yd. were paid for in embankment. As a matter of fact, practically all of the material was placed into embankment that was not trimmed up, and was, therefore, not estimated. During the month following, all these unfinished embankments were dredged out at a cost of only a few cents per cu. yd., so that in the cost of forming embankments distributed over the entire work, in- stead of being separated into months was quite low. The cost for November was as follows: A total of 45 (8-hr.) shifts were worked; and 20,516 cu. yd. were excavated at the following cost. Interest and depreciation $1,102.50 Coal, 90 tons @ $2.85 256.50 Labor 1,437.80 Teams 00.00 714 HANDBOOK OP EARTH EXCAVATION Oil, grease and waste $ 83.07 Gasoline 9.00 Repairs 94.50 Total $3,383.37 This gives a cost for excavation of 16.5 ct. per yd. Labor on embankment was practically all for building dikes and cost $782.50. The number of cu. yd. for embankment estimated dur- ing the month was only 513, giving the cost per cu. yd. of $1.52. A Record for Ladder Dredges. Engineering and Contracting, Jan. 18, 1911, reports that the Marmot of the Pacific Division, Panama Canal, a ladder dredge, broke all records for the daily, weekly and monthly output of ladder dredges in the Canal service during December. The output for the month was 219,795 cu. yd.; for the best week of 6 working days, 47,693 cu. yd., and for the best day (Dec. 14), 8,569 cu. yd. The output for the best 10-day period during the month was 77,838 cu. yd., or an average of 7,783 cu. yd. a day; for a 25-day period, 183,163 cu. yd. The average per working day over the whole month was 7,326 cu. yd. The above figures are based upon place measurement. The dredge was working the entire month in the approach channel to the site of the new docks at -the Pacific entrance to the Canal, excavating earth to a depth of 31 ft. below low tide. The crew set deliberately to work on Dec. 1 to exceed all previous records, and by request of the men themselves, the dredge was kept at work every day in the month, excepting Christmas day. All the dredges work night and day. The best previous record for old .French ladder dredges was made by the Atlantic Division dredge, No. 5, in July, 1909, which excavated 176,082 cu. yd. Elevator Dredge Work on Sunnyside Irrigation Canal. In a long paper by Moritz and H. W. Elder, in Engineering and Con- tracting, Sept. 11, 1912, the description and cost of elevator dredge work on the enlargement and improvement of the Main Canal of Sunnyside Yakima Project at Washington, is given. A floating dredge was used upon the first 21 miles. As the concrete lock structures, of which there were about 18, had a clearance of only 32 ft. between the walls, and as the dredge had to pass through these, the hull could be only about 30 ft. wide. This reduced the stability of the machine considerably. It would have been much easier to handle if it had had a wider hull. The machine used was a 3.5 cu. ft. steam driven continuous bucket, elevator type, with an 82 x 30 x 6.5-ft. hull, drawing 5 ft. of water. The steam was furnished by two 80-hp. locomotive type boilers, 44-in. by 18-ft. The main drive and ladder hoist was driven by a 70-hp., 8 x 12-in. double horizontal engine. Machinery for spuds and for swinging was driven by a 2 cylinder, METHODS AND COST OF DREDGING 715 20-hp., 6 by 6-in. double horizontal engine. The conveyers were driven by two 18-hp., 7 by 10-in. single cylinder horizontal engines. A no. 1 hydraulic giant, supplied by a 2-stage, 6-in. centrifugal pump, belted to an 80-hp., 10 by 12-in. single cylinder upright engine, was mounted in the bow, to remove the bank, beyond the reach of the bucket above the water level. The conveyors were 72 ft. long and had 32-in. rubber conveyor belts. This machine was operated from Dec. 4, 1909, to Oct. 1, 1911, and removed 921,- 000 cu. yd. of material. Had the running water been of sufficient depth at all times in the canal, much unnecessary excavation would have been saved; for the machine excavated in some cases 4 ft. below grade, in Fig. 8. Bucket Elevator Dredge, Sunnyside Canal. order to have sufficient water to float. A great deal of diffi- culty was encountered in disposing of excavated material. So much water was carried over with the earth and gravel, that a mud was formed, which ran out into the adjoining field orchard, covering the original ground to a depth of several feet. Bulk- heads had been built in an attempt to hold the material. This was found very expensive, so finally %-in. holes were bored in each bucket, to allow the water which was picked up with the dirt to escape. This accomplished a great deal toward retain- ing the material on the right-of-way. The statement of cost given below requires some explanation. The labor cost is low. The high cost charge to the item spoil bank is due to the fact that much of the material was deposited jn the form of muck that ran over valuable farm land; and had to be hauled back when dry, unless it had been retained by the expensive bulkhead along the right-of-way. Another reason for the high cost of this item, is that much of the material was 716 HANDBOOK OF EARTH EXCAVATION deposited in high mounds, which had to be graded down to permit ditch riders to travel over the levee. The high cost of maintenance was due to the fact that much adjusting and many changes had to be made to adapt the machine to local con- ditions. The depreciation item includes the entire cost of the machine ($41,400), charging it against the total yardage. Every- thing except the hull should have considerable salvage value, which will go toward reducing the cost. Fuel had to be hauled about 3 miles across open country or over roads that were very rough. LEGCNJO Old Ground Line Required Section - Dredge Excovat,on L me - Team Cxcovotion Lme Team work nil m ream work Spot H Team Excavation E3 Dredge Excavation Fig. 9. Typical Sections Excavated by Elevator Dredge. The most gratifying result of this work was , the solid lower bank produced by the saturated material discharged by the dredge, and the substantial roadway over it. The cost of 920,- 723 cu. yd. was: Per cu. yd. Labor, dredge $0.0:9 Labor, spoil banks 0.034 Fuel 0.036 Plant maintenance 0.057 Plant depreciation 0.045 Total per cu. yd $0.201 Miscellaneous. Maximum excavation per 8-hr, shift, 1,429 cu. yd.; maximum excavation for one week, 17,644 cu. yd. (three shifts) ; average excavation per 8-hr, shift, 557.9 cu. yd.; average excavation actual working hr., 128.7 cu. yd.; per cent, of lost time, 49; made up as follows: moving, 10%; repairs and miscel- laneous, 39%. Force and Wages. An operating force consisted of 8 men and 4 horses. METHODS AND COST OF DREDGING 717 718 HANDBOOK OF EARTH EXCAVATION Wages paid were: Operator, $5.00; engineer, $4.67; spudman, $3.83; fireman, $3.33; oiler, $3.00; deckman, $2.50; man and team, $4.50. Gold Dredging. In the bibliography at the end of this chapter will be found many references to articles on gold dredging. The elevator dredge is used almost exclusively for this class of work, so that any one who desires all the information available on this type of dredge should study the articles on gold dredging. Partly because these machines are too highly specialized to be of direct interest to the average earth excavator and partly because elimination in an almost endless field of information is necessary, gold dredging will not be discussed in this volume. Operating Cost of a Hydraulic Dredge. J. M. Allen, in En- gineering News, Oct. 29, 1914, gives the following: The tabula- tion gives the typical operating costs of a 15-in. hydraulic dredge on the Mississippi River, in 1914, working two 12-hr, shifts. Wages do not include subsistence. Assuming an output of 75,000 cu. yd. per month, the cost is about 6 ct. per yd. 1 foreman $ 150 1 engineman 125 1 engineman 100 2 suction operators, at $100 200 2 oilers, at $60 120 2 firemen, at $70 140 2 coal passers, at $60 120 3 deck hands, at $60 180 1 levee foreman (day) 90 1 levee foreman (night) 70 10 levee laborers, at $60 600 26 Total labor cost per month $1,895 Coal (18 tons per day) 1,200 Supplies (rope, oil, packing) 150 Repairs and renewals 200 Office and over head expenses 200 Insurance (fire and liability) 100 Interest and depreciation (2% on $35,000) 700 Total operating cost per month $4,445 Hydraulic or Suction Dredges. There are four general classes of this type of dredge: (1) The seagoing hopper type without anchorage; (2) the lateral feeding type, with 5 or 6 mooring lines to anchors, for use in wide channels; (3) the forward feed- ing type with one or two forward mooring lines to anchors; (4) the radial feeding type with spud anchorage. Hydraulic dredges may also be classed thus: (1) Plain suction pipe dredges; (2) with water jet agitators; (3) with mechanical agitators or cut- ters. Cutters are generally necessary for material other than sand. The forward feeding type of dredge is adapted to work in METHODS AND COST OF DREDGING 719 720 HANDBOOK OF EARTH EXCAVATION shallow alluvial rivers such as the Mississippi, and for this reason it is often called the Mississippi type dredge. Almost all of the work on the Mississippi River is done by the government. The Alpha was the first dredge of this type built for the Missis- sippi River Commission. This was followed by the Beta and Gamma. The radial feeding type of suction dredge is usually anchored by one or more spuds, the suction pipe making a radial cut on the arc of a circle about the spud as a center. This is the com- mon type of dre:lge for general work. The seagoing type is confined to harbor work, and the forward feeding type is used on alluvial rivers. The Floating Pipe Line. The pipe line of a dredge is generally built of thin sheet steel. Almost any kind of floats are used in quiet waters. In exposed situations the pipe and floats are built of heavy ma'terial, solidly constructed. A water velocity of 7 ft. per sec. in clay or mud, or of 10 ft. in sand generally gives good results. For moderate distances velocities of 12 to 16 ft. per sec. are sometimes employed. The percentage of solids varies up to 75%. It is less difficult to transport a large per- centage of solid material after it has entered the pipe line than to introduce it into the pipe without choking the pump. At Oakland, California, a dredge belonging to the Atlanic Gulf and Pacific Company delivered material through 6,170 ft. of 20-in. pipe. Other dredges built by this company for the Baltimore Water Works p mped through pipe lines 10,800 ft. long, but part of this line was down grade giving a 10 ft. negative ahead. The Output and Cost of Operation. This varies widely. In the centrifugal type the construction of the dredge itself has a large influence upon the cost of operation and repairs. The type of pump selected is particularly important. The side suction type gives an easier passage through the larger bends and is therefore generally preferred, but the double suction type of pump avoids side thrust. The shape of the pump and vanes also has a material effect upon its wearing qualities. A badly de- signed pump, especially when excavating sharp sand, will wear out in a very short time. The mooring and dredging moving eq- ipment, and the digging, cutting, or agitating appliances are also of the greatest importance. Robert A. Cummings, in Transactions American Society of Civil Engineers, vol. 31, 1894, states that with centrifugal pumps for silt and alluvial deposit 30 to 40% of solids, and for coarse gravel and fine sand 10% of solids is the best proportion of the volume pumped. It is stated in Engineering News, Dec. 15, 1898, that with the METHODS AND COST OF DREDGING 721 12-in. dredge the discharged material ordinarily consisted of about 10% of solid matter. At times, however, the 1,000 ft. of dis- charge pipe would start to clog up, but by increasing the speed of the pump the material was forced out in a nearly solid mass that would break off in lengths of 15 to 18 in. The water in which the dredge worked was furnished from a source 1,700 ft. distant by a 12-in. pump through a 6-in. dis- charge pipe. The soil was clay naturally wet and soft because of seepage water and therefore unfavorable to dry excavation methods, but decidedly favorable to hydraulic dredge work. Depth at Which Suction Dredges Can Work. The Engineer- ing and Mining Journal, Nov. 7, 1914, describes a dredge made for the Calumet and Heckla Mining Co. for use in, working over stamp mill tailings in Torch Lake, Mich. This dredge is equipped with two 20-in. centrifugal pumps, one driven by a 750-hp. motor, and the other by a l,2o()-hp. motor. Previous to the construction of this dredge the greatest depth attained by suction dredge was 70 ft., which depth has been reached by the sand suckers work- ing in Long Island Sound. The Calumet and Heckla dredge is intended to dig to a depth of 100 ft. Dredging in Mobile Harbor, Alabama. Engineering and Con- tracting, Mar. 20,. 1012, gives the following: Three types of dredges have been employed in improving and deepening the ship channels in and about Mobile Harbor. These are the clam shell, the seagoing suction and the hydraulic pipe line. In an article in Professional Memoirs for March-April, 1912, Assistant Engineer J. M. Pratt describes the work of these dredges. A comparison of output and cost is made between a clam shell and a hydraulic dredge. Records of work are given of one seagoing hopper dredge and three hydraulic pipe line dredges, including costs and statement of delays. Structural defects and advantages of the dredges are specified. Comparison of Clam Shell and Pipe Line Dredge. The Mobile Harbor dredged channel extends from Chickasaw Creek, 4.8 miles above the mouth of Mobile River, to deep water in the lower portion of Mobile Bay, a total distance of 33} miles. The ma- terial along the upper six miles of this channel consists prin- cipally of sand and clay with some mud. Along the next eleven miles it is mud and sand with strata of shells at the lower por- tion. The material along the remainder of the channel is com- posed of a soft blue mud having a specific gravity, as it lies on the bottom, of about 1.36. From the head of the channel in Mobile River to a point ten miles below, the dredged material either has to be deposited on shore or towed several miles in scows, because the water on the edges of the channel is too shoal 722 HANDBOOK OF EARTH EXCAVATION for loaded scows to get out. A dredge would be protected from storms, unless of unusual severity, while working in the channel in Mobile River, and be better protected while working in the upper portion of Mobile Bay than in the lower portion, thus making delays in dredging on account of weather conditions much less in the upper than in the lower bay and reducing them to a minimum in the river. All of these considerations make it difficult to form a comparison between two dredges working in this channel, unless engaged near the same locality at the same time. However, a fairly good comparison may be obtained of a clam shell and a hydraulic pipe line dredge by taking the records made in 1909 by the clam shell Sredge A and the hydraulic dredge B, both belonging to contractors and working under the same contract a few miles apart in middle and lower Mobile Bay. The yardage dredged represents the amount excavated from the theoretical section in either case, or the amount paid for and not the total amount removed. The time extends from April 1 to July 12, the hydraulic dredge working two days longer in July than the clam shell, which discontinued work on the 10th. The material in each case was mud, although that obtained by dredge A was much softer and more easily handled than where the hydraulic dredge was working during April and May. In June this dredge reached a point near where dredge A had been working, and her results were largely increased. These dredges are both representative of their respective types and the material was deposited by each about 1,200 to 1,500 ft. from the channel. Dredge A has an 8^-cu. yd. clam shell bucket and dredge B has a 20-in. centrifugal pump with a 22-in. suction and 20-in. diameter discharge. The following table shows the amount dredged per month and the delays to each dredge. Time lost Month Ou. yd. Hr. Dredge A. April 1 to 30 , 208,922 157 May 1 to 31 195,231 179 June 1 to 30 155,016 173 July 1 to 10 70,567 56 Total 629,736 565 Dredge B. April 1 to 30 226,294 114 May 1 to 31 244,350 161 June 1 to 30 410,821 67 July 1 to 12 142,576 44 Total ....' 1,024,041 386 The time lost in each case does not include Sundays or legal holidays, but is a portion of the total effective working time. METHODS AND COST OF DREDGING 723 This work was done at a contract price of 9.95 ct. per cu. yd., but during the last two contracts work has been done at this locality for a little less than 6 ct. per cu. yd. Figuring on this basis and estimating the value of each outfit to be: $75,000 for dredge A and attendant plant, and $125,000 for dredge B and attendant plant, the value of each in earning power is as follows : Dredge A 629,736 cu. yd. dredged, at 6 ct $37,784 Interest on $75,000 for 3^ months, at 6% $ 1,250 Depreciation at 10% per annum, for 3^ months 2,083 Cost of operating dredge, 3^ months 14,300 17,633 Amount earned $20,151 Dredge B 1,024,041 cu. yd. dredged, at 6 ct $61,442 Interest on $125,000 for 3^ months at 6% $ 2,083 Depreciation at 10% per annum, for S 1 /^ months 3,472 Cost of operating dredge, 3^ months 28,333 Amount earned $27,554 Thus, in a little over three months, the hydraulic dredge earned about $7,500 more than the clam shell dredge, though the latter was one of the best ever seen in this district. The hydraulic dredge experienced fewer delays in general, and could work as long during rough weather as the clam shell dredge, the latter, of course, having to quit work when it became too rough to land scows alongside. Mr. Pratt describes an interesting expedient resorted to to remedy a difficulty encountered with the Seagoing Hopper Dredge Charleston which decreased its output in very soft mud. It was found that when the drag was lowered below the surface of the material that it buried in the mud, the pipe would continually choke, and the drag would then have to be lifted in order to ad- mit sufficient water to clear it. This, of course, would put a great deal of water in the bins which could not be disposed of, and simply decreased the amount of material carried at each load. If the drag were kept near enough to the surface of the material to prevent choking, a large percentage of water was admitted, and the result was practically the same. The only way then to obtain a maximum amount of material in the short- est time was to bury the drag below the surface of the ma- terial, move slowly along the cut as before, and admit just enough water in the drag to pump the material without choking it or having to raise the drag. This was accomplished by cut- ting a hole in the top of the drag and fastening thereon a pipe (Fig. 12), 5% in. in diameter and 12 ft. long, which ex- 724 HANDBOOK OF EARTH EXCAVATION tended up the outside of the main suction pipe and was fastened thereto. A valve was placed in the upper end of this 5%-in. pipe, as this was always above the surface of the material on the bottom, and just enough water admitted to enable the pump to work properly. When shifting the dredge from this locality to the other bar, this pipe was removed and a steel plate put in its place, filling up the hole in the drag. The value of this pipe to the dredge when working in very soft material may be seen from the fact that before installing this pipe the average time required to load 200 cu. yd. was 49 min., and after the installation only 25 min. were required. Length Rff _ {4 Lap-, 6 *$ Pie Bent lo fit Suction Llevation Fig. 12. EngKontg. Nipple-.^ Bent To 1 'it. , Drag " Improved Suction Pipe for Seagoing Hopper Dredge Charleston. Dredging Ocean Bars. The following data relative to work done at various harbors by three government dredges, have been abstracted from a paper by Major J. C. Sanford in Transactions American Society of Civil Engineers, vol. 54, part C, 1905. The following are monthly reports for July, 1904, of the Gedney, working at New York Harbor; the Gen. C. B. Comstock, working at Galveston, Tex., and the Sabine working on the bar outside the mouth of South Pass, Mississippi River. These may be taken as typical of the work of the older and smaller class of dredges under rather favorable conditions. DREDGE GEDNEY Location of work, north side of Gedney Channel, New York harbor Depth of water (survey of Jan., 1904) 27 to 30 ft. M. L. W. Depth required 30 ft. M. L. W. Range of tide 4.6 ft. Material dredged Sand and gravel in varying proportions Cubic yards removed 53,193 Loads ./ * )( J W METHODS AND COST OF DREDGING 725 Yards carried per load, average 604 " dredged per minute, average 15.0 Time dredging 59 hr. 14 mm. turning 2 " 37 running to dumping ground 53 " 48 Average speed, loaded 5.4 knots Time running from dump to working ground 32 hr. 11 m n. " " anchorage 18 " 24 " wharf 18 " 02 anchorage to working ground 12 " 59 wharf to working ground 12 " 29 " anchorage to anchorage 1 " 12 lost repairing (while under steam) 1 " 06 " lost from other causes (while under steam) 05 dumping 11 " 45 Average time dumping per load 8 mm. Total time under steam 223 hr. 47 min. Average speed, light 6.9 knots (to and from wharf) 7.4 Approximate speed while dredging 1.5 Time lost due to fog 1*4 days " rough sea ^ ' ' repairs % " coaling ship 2% " other causes % actually working 19% Distance from working grounds to dumping grounds, mean. 3.3 nautical miles Coal burned (pea coal) 207 long tons Water used 35,300 gal. Average cost of dredging per cu. yd. (based on actual cost of coal, water, rent of wharf, wages of crew, and mess bills, and on aver- age of ten years' cost, per working day, of repairs and supplies). 5.9 ct. DREDGE GE-N. C. B. COMSTOCK Quantity of material dredged 67,476 cu. yd. Character of material dredged Sand, mud and clay Distribution of working time: Anchorage to cut 9 hr. 55 min. Pumping 147 ^ 29 Cut to dump 33 Dumping 8 Dump to cut 25 " 27 Dump to anchorage 10 Time lost turning " 00 Total hours worked 234 hr. 46 min. Time lost on account of bad weather, Sundays and holidays, wash- ing out boilers and repairs 220 hr. 37 "" Cost of operating for the month - $2,888 Cost of extraordinary repairs for the month 774 Fuel consumed, 845 bbl. fuel oil at 70 and 75 ct. per bbl. The dredge Sabine was transferred on July 13, 1904, for work beyond the ends of the jetties at South Pass. The dredge left New Orleans on July 14, arrived at Port Eods on July 15, and began work beyond the ends of the jetties on the same day. The material removed consists principally of a stiff clay or mud, with some sand. Between July 15 and 30, the dredge worked 161.5 hr., distributed as follows: 726 HANDBOOK OF EARTH EXCAVATION Moving to and from dredging position 13 hr. - Pumping 102 " Dumping 28 " Repairs 12% " Taking aboard fuel 6 " During this time the dredge removed 286 loads of material containing a total of about 55,770 cu. yd. of solid matter. The expenses of the dredge from July 13 to 31, were about $1,250, making the average cost per cu. yd. of material removed about 21/4 ct. From the 13th to 31st, 439 bbl. of fuel oil were consumed, of which 401 bbl. were used in connection with the dredging operations proper. In August, 1904, this dredge removed 67,- 860 cu. yd. at this locality, the average cost for working ex- penses being 3 ct. per cu. yd. Work of Hopper Dredges in Ambrose Channel. Two dredges, " Thomas " and " Mills " were constructed after the " Liverpool type " of dredges for the Metropolitan Dredging Co., to work in New York Harbor. These dredges were each self-propelling steamers of 7,000 tons displacement, 300 ft. long, 52.5 ft. beam, with a hopper capacity of 2,800 cu. yd., and a speed of 10 knots. The draft when empty was 13 ft., and when loaded 18 ft. Each was equipped with a double-suction, 48-in., centrifugal pump. The suction pipe was 48-in. diameter, and operated through a longitudinal well in the vessel. The hoppers or bins were dumped through bottom valves. The cost of each dredge was about $475,000. At work in New York Harbor, sand (70%), with clay (5%), gravel and small stones was the material dredged. The sand fed freely. The maximum rates of loading were as follows: 2,850 cu. yd. in 32 min.; 21,624 cu. yd. in 1 day; 285,551 cu. yd. for one dredge in 1 month; 552,297 cu. yd. for both dredges in 1 month. During the 12 months ending June 30, 1902, the two dredges removed 5,015,568 cu. yd. of sand, of which 923,176 cu. yd., or 18.4%, were from below the required depth, leaving a net output of 4,092,392 cu. yd., or 170,516 cu. yd. per month per dredge. The large amount cut from below grade was due to the method of working the Liverpool type of dredges. The vessel was an- chored while dredging and thus deep holes with intervening high ridges resulted. It required from 3 to 6 moves to obtain a full load. Naturally an uneven bottom was left. During 562 working days previous to May 31, 442 (78.7%) days were actually worked, 88 days (15.7%) were used for re- pairing, and 32 days (5.6%) were lost during bad weather. During the working days, 15^4 hr. per day were worked, the re- METHODS AND COST OF DREDGING 727 mainder of the time being charged to weather, coaling, minor repairs, and lack of steam. The time occupied in pumping, removing and dumping an average load of 2,500 cu. yd. was 3 hr. 50 min., of which 1 hr. 45 min. was spent in going to and returning from the dump (12 miles), and 15 min. in dumping. The crew required for day and night work on each dredge was 54 men; the monthly payroll was $2,700 per dredge. Work of U. S. Dredges in Ambrose Channel. Henry N. Bab- cock, in Engineering and Contracting, Oct. 3, 1906, gives the fol- lowing: The two dredges "Manhattan" and "Atlantic" differ essentially in their method of operation from the Liverpool type of dredge described in the last paragraph. The Liverpool type of dredges dredged while stationary, and thereby sunk holes to great depths. The ridges between these holes did not wash away to the extent that might be expected. This was due to the nature of the sand, which varied from medium fine to coarse, was hard packed and possessed much stability. Dredges of this type were successful at Liverpool, England, where the bottom is a fine quicksand which ran into deep holes as soon as they were made. To overcome this defect the government vessels were designed to dredge while proceeding at low speed, thus removing a strip of approximately constant depth from the channel bottom. The following relates to the work of these dredges during their first season. These vessels were of the same plan, each being steel, twin- screw steamers, 288 ft. long, 48 ft. wide, with two self-contained sand-bins, holding about 2,300 cu. yd. when fully loaded. Each dredge was equipped with two 20-in. centrifugal pumps, 20-in. suction pipes, and 4 boilers each 14 ft, diameter Jby 12 ft. long. After certain trials, the dredges " Manhattan " and " Atlantic " began actual work at Ambrose Channel on Feb. 8, 1905. The material was excavated to a depth of 40 ft. It consisted mainly of coarse and fine sand and gravel, a small amount of clay, some mud, and about 3% of miscellaneous refuse such as paving blocks, timber, iron, chain, etc. Each dredge had two drags, which made two furrows each 5 ft. wide, 3 or 4 in. deep, and about 52 ft. apart. With the vessel proceeding at speeds of 1.5 to 3 miles per hr., a load of 2,200 cu. yd. (about 1,800 cu. yd. place measure) was removed in a length of 15,000 to 20,000 ft. The courses were laid out so that a dredge obtained a full load in going up and back once. The distance to the dumping grounds was about 8 miles. The 728 HANDBOOK OF EARTH EXCAVATION average time going loaded was 46 min., and returning empty 36 min., a total of 82 min. (or 28% of total working time) for an average load of 2,044 cu. yd. Up to Aug., 1905, dredging was performed during the day, but since that time both day and night. Night work is about 90% as efficient as day work. Up to July 1, 1905, the dredges were undergoing many alter- ations and repairs. During 8 months' work of one dredge and 2 months' work of the other 467,450 cu. yd. (46,745 cu. yd. per dredge month) were removed at a cost of 9.9 ct. per cu. yd. From July 1, 1905, to May 31, 1906, both dredges, working 11 months each, removed 3,258,707 cu. yd. at a " field " cost of 5.3 ct. per cu. yd. The itemized cost was as follows: Ct. per cu. yd. Pumping 3.357 Turning 0.206 Going loaded 0.835 Dumping 0.223 Returning empty 0.653 Total per cu. yd 5.274 It will be noticed that about one-third of the total working time is spent in travelling and dumping the load. Divided according to items of expense, the cost was as fol- lows : f 'V ! - Ct. per cu. yd. Payroll 1.761 Coal 1.408 Water ' 0.039 Subsistence 0.476 Engine-room supplies 0.098 Miscellaneous supplies 0.150 Repairs and renewals 1.342 Total per cu. yd 5.274 These vessels are very sea- worthy and remain at work as long as it is possible to dump at sea. The week's work begins at 5 A. M. Monday, when they leave their docks. At noon Saturday they return to dock and that night or on Sunday they take on coal and supplies, clean boilers, etc. During the period, July 1, 1905, to May 31, 1906, out of 670 days of 24 hr. each, 335.1 days (50%) were spent actually at work, 138.1 days (20.6%) were lost while repairing, 11.5 days (1.7%) on account of fog and snow, 13.4 days (2,0%) on account of storms, 46 days (6.9%) while taking on coal, in making minor repairs, etc., 3.7 days (0.6%) on account of miscellaneous delays, 12.2 days (1.8%) in July before night work began, and 110 days (16.4%) on Sundays and holidays. METHODS AND COST OF DREDGING 729 The estimated total cost of work of one dredge for one month is given below. The unit cost is based on the average monthly output of one dredge during the twelve months ending June 30, 1906, of 158,100 cu, yd. During June, 1906, the two dredges excavated 535,692 cu. yd. (267,846 cu. yd. each). The crew required on each dredge numbers 54 men, the wages paid being as follows: Deck: 1 engineer inspector $ 166.66 9 oilers at $45 405.00 1 master 175.00 9 stokers at $40 360.00 1 mate 120.00 3 dredgemen at $40 120.00 1 cook 60.00 4 dredgemen at $30 120.00 } cook 45.00 6 deckhands at $35 210.00 1 c ok 7 deckhands at .$30 210.00 3 waiters at $20 60.00 Engine Room: Carpenters: 1 chief engineman 150.00 1 (Vz time to each dredge) 1 assistant engineman 110.00 at $60 30.00 1 assistant engineman 90.00 1 assistant engineman 75.00 Total $2,701.66 The actual pay roll has varied from $2,406 to $2,709, the aver- age being about $2,660. The deck crew works 12 hr. per day while dredging and 8 hr. per day while repairing. The engine room men and the computers work 8 hr. per day. The fuel used is free burning bituminous coal, purchased under different con- tracts at prices ranging from $3.01 to $3.25 per ton of 2,240 Ib. Per month Payroll $ Coal 2,480 Water 60 Subsistence 700 Engine-room supplies 150 Other supplies 250 Casual repairs 500 Total operating expenses : ' $ 6,800 Docking, painting 2 times per year $1,250 Renewals of equipment, per year 12,150 Miscellaneous, per year 1 1,000 Total maintenance per year $14.400 Total maintenance per month $1,200 Depreciation fund, 10% on $341,800 $34.180 Interest at 4% 13,672 Insurance at 2% Total fixed charges per year Total fixed charges per month $ 4,500 Grand total per month $12,500 730 HANDBOOK OF EARTH EXCAVATION Note that the rate of interest is very low. Also note that the dredge is assumed to work 12 months every year, which is usu- ally unattainable over a long period of years. The field cost of dredging already stated was 5.27 ct. per cu. yd. The cost of interest, depreciation, and insurance ($4,500) divided by the average monthly output of 158,100 cu. yd., gives a further charge of 2.85 ct. per cu. yd., which brings the total cost of dredging to 8.12 ct. per cu. yd., which is slightly less than the price bid by a contractor of 9 ct. per cu. yd. It should be noted that the cost of repairs is probably less than the cost of repairs on an older boat. In Professional Memoirs, January-March, 1909, Capt. H. L. Wigmore gives further cost data of the work of the Manhattan for 1908 in Ambrose channel. This article was abstracted in Engineering and Contracting, Sept. 22, 1909. Below is given cost of operating the Manhattan, with further data showing the cost to a contractor and to the government. In calculating the cost to a contractor the cost of surveys and examinations should not be considered, but the cost of interest, depreciation, and in- surance should be. All of these items, except interest and in- surance, should be included in an estimate of the cost to the government. Pay roll : $31,891.63 Coal 34,820.06 Subsistence 12,390.46 Supplies 4,704.84 General repairs 20,369.61 Wharfage 777.50 Total ! $103,954.10 The total yardage of the " Manhattan " for the period from June 30, 1907, to June 30, 1908, was 2,660,513 yd. Taking the total cost of operation as $103,954.10, which includes all items of ex- pense which would be borne by a contractor, we have a cost per yd. of $0.039 Building cost of " Manhattan " was $340,041.58. Ten per cent, sinking fund, $34,004.16 = per yd .013 Insurance and interest taken at 7%, $20,802.91 = per yd Cost to a contractor ..................................................... $0.060 There should be added an allowance of 12%% in this case for over depth in dredging for which the contractor is not paid = per yd ................................................................. 006 Total .................... ......................................... $0.066 Total cost to the United States was as follows (excepting cost of vessel) : For cost surveys and examinations for two boats $19,983.34 or $9,991.67, chargeable to the " Manhattan " per cu. yd ........... $0.004 METHODS AND COST OF DREDGING 731 For office and contingent expenses $6,752.15. $3,376,075 for the " Manhattan." To this should be added $1,500 for the inspect- or's salary per cu. yd 002 Operating as before per cu. yd ..' "* Sinking fund as before per cu. yd uw Total cost to the United States $0.058 Sea-Going Hydraulic Hopper Dredge for North Pacific Bars. Engineering News-Record, Nov. 8, 1917, describes a dredge built to meet the extreme conditions of digging and seaway encoun- tered on the sand bars of the river entrances of the North Pacific, particularly at Coos Bay, Oregon. The Col. P. S. Michie was designed in the office of the chief of engineers and placed in commission in the spring of 1914. She was constructed in the yards of the Seattle Construction and Dry Dock Co. and delivered ready for service in 16 months from date of award of contract, at a cost of $378,198. The dredge is of steel construction, has a length of 244.6 ft. over-all, molded amidship width of 20 ft.; draft, light, of 11 ft., draft, loaded, of 17 ft.; displacement, light, of 1,708 tons and displacement, loaded, of 3,372 tons. Her speed, light, is 10 knots and loaded 8 knots, and the speed maintained while in operation is 1^ knots; en- gines, 1,780 hp. There are six bins, three on each side of the well, having a combined capacity of 1,400 cu. yd. These bins are fitted with overflow weirs which dispose of all surplus water. Openings are also provided below the level of the maximum capacity to permit the dredge to operate on a lighter draft if necessity demands. A trap gate in the bottom of the bins releases the material. The bins can be filled or dumped with dredges singly, collectively or in pairs. In order to keep the vessel from listing, especially in heavy seas, it is the practice to empty partly the two for- ward hoppers, then to dump the four after hoppers. The dredge actually fills the hoppers in 45 min. and it is able to dump its entire load in 7 min. The lower end of the dredge arm is fitted with a drag head of the usual type used by sea-going dredges. The first drag head used was made of ordinary steel and was in serviceable condition for about 30 days of actual use. A new drag made of manganese steel has seen two years of actual service and has handled as many as 27 cu. yd. of material per min. over long periods of operation. The dredge arm has been operated in 42 ft. depth of water and in this position has an angle of 30 from the vertical. All movements of the dredge arm, pumping, disposing of material, etc., are mechanically operated, the chief operator's 732 HANDBOOK OF EARTH EXCAVATION METHODS AND COST OF DREDGING 733 station being located conveniently to afford a clear view of all movements. When dredging operations began in 1914 there was 17 ft. of water on the bar. The following is a record of the first season's work of the Michie. The unit cost of dredging for the season was 14.6 ct. per cu. yd., of which the labor cost = 6.8 ct. per cu. yd. and fuel oil = 3.1 ct. per cu. yd. The pumping average for the season was 14.5 cu. yd. per min. The cost of dredging for the season of 1915 was 5.13 ct. per cu. yd., of which the labor cost was 1.95 ct. per cu. yd. and fuel oil 1.6 ct. per cu. yd. Operations for the month of March give a record well worthy of consideration. This month the cost of dredging was 2.88 ct. per cu. yd. The costs given include all overhead expenses, including a 2% charge for Portland* office ex- penses, but do not include the expenses incurred by the dredge while out of commission. Filling Behind Bulkheads. The cost of dredging by Seattle and Lake West Waterway Company is given by C. H. Rollins in a paper read before the Pacific Northwestern Society of Engi- neers, May, 1904. Dredging was performed by a Bowers pattern dredge, filling behind bulkheads of brush and dikes of sand with straw or hay embedded in them. The outlet for the waste water was through vertical sluice boxes from the bottom of which other horizontal boxes extended to a point beyond the fill. Other bulkheads were of piles and planking. The brush bulkheads were the best for they were semi-permanent. Brush bulkheads were in good con- dition after being in place 9 years. Brush bulkheads were constructed as follows: Young fir brush was so placed with the butts out as to give a slope of 1 or 1^ to 1 to the face. The top width of the biflkhead was 12 ft. Piles were driven in 2 rows 10 ft. apart, piles being 6 or more ft. apart on centers. Planks were temporarily spiked to the piles to hold the brush in place. The brush was kept a little above the fill at all times. This type of bulkhead permitted the water to waste rapidly but held nearly all of the filling material. Temporary Pile and Plank Bulkheads were constructed by driv- ing piles in 2 rows, 8 to 10 ft. apart, with piles at 8-ft. centers. The outer row of piles was braced with 1^-in. planks to the inner row, and the inner row was braced with planks to anchors in the fill. Planks were spiked to the inside of the outer row of piles for half their height, and to the inner row of piles for the remainder of the height of the fill. The planks were 734 HANDBOOK OF EARTH EXCAVATION 1% in. (or occasionally 3 in.) thick. This type of bulkhead was inexpensive and satisfactory. The dredging was performed by two 20-in. suction dredges. The Man Diego was equipped with a 600-hp. engine and a rotary cut- ter, and could dig to over 50 ft. in depth. The 30-in. discharge line was supported at the shore and by tackles from derrick scows. The Portland was equipped with 800-hp. engine and 22-in. discharge. Hydraulic Dredging at Oakland Harbor, Cal. L. J. Le Conte in Transactions, American Society of Civil Engineers, Vol. 13 (1884) gives the cost of dredging with a hydraulic dredge. This machine was equipped with a rotary cutter for work in hard material, 20-in. suction pipe, a centrifugal pump, two 16 x 20-in. pump engines, two 12 x 12-in. cutter, hoist, and winch engines, and two 100-hp. boilers. The material excavated was sticky, blue clayey mud. The percentage of solid matter dis- charged from the pipe line varied up to 40% ; the advisable maximum percentage was 15%. During the years 1883 to 1886 inclusive, in 23 working months, 1,201,370 cu. yd. were excavated, an average of 52,233 cu. yd. per month. The length of the discharge pipe line varied from 900 to 3,900 ft. The maximum monthly output was during Oct., 1885, when 85,902 cu. yd. were discharged in 269 engine-hr., through 3,400 ft. of pipe line. In Apr., 1884, 63,080 cu. yd. were discharged in 275 engine-hr. through 3,900 ft. of pipe. The monthly expenses were as follows: Per month 1 captain $ 200.00 1 engineman 100.00 2 firemen at $60 ^ 120.00 1 mate 60.00 2 guy-tenders at $40 80.00 3 deckhands at $40 120.00 1 cook 60.00 Board for 11 men at $15 165.00 Coal, 62.5 tons at $9 562.50 Oil, 25 gallons at $1 25.00 Water, 1,500 gal. at 1 ct 15.00 Repairs to dredge and pipe line 300.00 Interest on plant, $50,000 300.00 Depreciation 208.50 Insurance 167.00 Taxes 50.00 6 shore men at $60 360.00 52,233 cu. yd. at 5.5 ct $2,893.00 Hydraulic Dredging at Rockaway, N. Y. Engineering Record, Sept. 22, 1900, contains a description of an embankment between Brooklyn and Rockaway, New York City, which was formed of hydraulic dredged material. The embankment was 70 ft. wide METHODS AND COST OF DREDGING 735 and 5 ft. above high water. The original marsh surface was at about the high water level, and the material was mud for a depth of 15 ft., with coarse sand beneath. A hydraulic dredge cut a channel 200 ft. wide and 35 ft. deep, and discharged the material in the fill in a direction parallel to the 'axis of the fill, and between longitudinal turf dikes. The waste water percolated through the turf, leaving the embankment firm enough to walk upon within a few hours. The turf of which dikes were formed was cut from adjacent salt marshes, and was laid up like masonry with a base as wide as the dike was high, and a top 2 ft. wide. The outside face was battered. The ordinary height was 6 ft. and above this the fill was retained by temporary wooden hurdles, made in sections 16 ft. long and 3 ft. high and by a horizontal platform 3 ft. wide built into the fill so as to give stability. The lumber used was matched 1-in. hemlock, nailed to 3 x 4-in. cross-pieces. The first cost f each 16-ft. hurdle was $4 to $5, and it cost 50 ct. each time one was shifted. Turf dikes 6 ft. high were constructed by 5 men at the rate of 20 lin. ft. in 10 hr., or nearly 3.6 cu. yd. of turf wall per man per day. In forming the embankment, mud was deposited first and the sand on top. The fill was made 9 ft. high, but in a few days settled to a permanent height of 5 ft. above high water. The settlement of the embankment caused an upheaval of the mud on both sides. The dredge had a 16-in. suction pipe, a 15-in. centrifugal pump with a diameter of 7 ft., and a 350-hp. engine. It had a rated capacity of 16,000 cu. yd. delivering a distance of 500 ft. in 32 working hr., or 500 cu. yd. per hr, when conditions were favorable. This .dredge built 100 lin. ft. of fill in 10 hr., or 1,300 cu. yd. of 5 ft. fill. In one month a 90,000-cu. yd. fill was made, the dredge working 2 daily shifts of 12-hr, each. This was at the rate, of about 1,700 cu. yd. per shift, or 150 cu. yd. per hr. When de- livering material a distance of 1,100 ft. to an' elevation of 20 ft. the discharge contained up to 30% of solid material. Cost with Hydraulic Dredges on the Massena Canal. Engi- neering Xews, Oct. 30, 1902, gives the following data relative to the work of centrifugal pump dredges on the Massena Canal, from a paper read before the International Navigation Congress by John Bogart. Dredge No. 1 was equipped with a 12-in. centrifugal pump, a rotary cutter, a compound condensing engine of 125 hp., and 12-in. suction and discharge pipe. This machine handled soft clay, loam and sand, but could not dredge indurated clay. The material was dredged at depths up to 22 ft., and discharged 30 736 HANDBOOK OF EARTH EXCAVATION ft. above the water level through 1,200 ft. of pipe. The discnarge averaged 25% solid material, the range being from 7 to 30%. Dredge No. 2 was similar to No. 1 except that it was larger. It was equipped with 18-in. suction and discharge pipe. The material handled and the distance it was conveyed were exactly the same as for No. 1. Each dredge worked two shifts of 11 hr. daily. Dredge No. 1 required the following crew per shift: 1 captain, 1 engineman, 1 oiler, 1 fireman, 1 deckhand foreman, 3 laborers at 15 ct. per hr. The total pay of 18 men for 11 hr. was $17195. Dredge No. 2 required one more man (a spudman), and the total pay per shift was $20.95. . Dredge No. 1 worked 209 days each season. Careful observa- tions for 194 days showed the average daily output to be 1,125 cu. yd. per day. Dredge No. 2 worked two seasons and removed 290,780 cu. yd., or an average of 1,544 cu. yd. per day. The daily (2 shifts) cost was as follows: 12-in. dredge 18-in. dredge Labor and supervision $35.90 $41.90 Coal at $3 per ton 27.00 54.00 Oil, waste, etc 5.00 8.00 Care during winter at $209 1.00 1.00 Interest, depreciation and repairs 26.80 40.19 Total per day $95.70 $145.09 Cost per cu. yd., total, ct 8.50 9.40 (Dredge No. 1 cost $40,000; dredge No. 2 cost $60,000. Interest at 4%; depreciation and repairs at 10%.) Suction Dredge at Warroad River, Minn. At Lake of the Woods, Minn., a plant consisting of a suction dredge, wood barge, pipe line and floats, and small boats, total cost $29,130, was" used to excavate a navigable tributary, the Warroad River. The work of this outfit is described by Emile Low in Engineering News, Nov. 29, 1906. The dredge hull was 100 ft. long, 27 ft. wide and 8.5 ft. deep amidship. The total length, including the ladder and revolving cutter, at the bow and the stern paddle-wheel, was 185 ft. The hull contained a sand bin amidship with a capacity of 100 cu. yd. The machinery included two 12-in. centrifugal pumps, one 16-hp. cutter engine, one 20-hp. hoist engine, two 10 x 60-in. stern wheel engines, one 6 x 10-in. duplex force pump, and four hand-power worm gears for operating the spuds. Steam was supplied by two 75-hp. marine boilers. From May 7 to June 30, 1904, this dredge excavated a channel 1,380 ft. long, 100 ft. wide, and an average of 8 ft. deep, a total METHODS AND COST OF DREDGING 737 of 8,625 cu. yd., at a total operating cost, including fuel, of 21.67 ct. per cu. yd. Storms caused a loss of 5.5 days. From July 1 to Oct. 29, 1904, a total of 26,923 cu. yd., or a daily aver- age of only 259 cu. yd., were dredged. Storms caused a loss of 12.3 days. The material dredged was equal quantities of hard- pan and mud with fibrous roots of bullrush, etc. The total excavation for the twelve months preceding June 30, 1905, was 55,205 cu. yd. The cost, including fuel, was 13.03 ct. per cu. yd. Dredging Silt with a Small Centrifugal Outfit. In order to remove the mud from the bottom of a Pittsburg reservoir, a dredg- ing plant of simple construction was used. F. B. Marsh, in Engi- neering Record, Sept. 3, 1904, gives the following: Two 50-hp. boilers, located on a dividing wall in the reservoir, and protected by board covering, supplied steam through a line of 4-in. pipe to the engine. The engine was of 75 hp., and was in- stalled with an 8-in. Morris Centrifugal pump and the necessary suction pipes and other equipment, on a float, 20 x 30 ft. in size. The steam pipe was of wrought iron with a 40-ft. section having at each end a flexible ball-and-socket joint between two quarter- bends. This pipe, supported on the surface of the water by floats, permitted the dredge to swing freely. Rubber pipe connections were unsuccessful. The suction pipe consisted of a 10-ft. length of rubber hose with a 22-ft. length of wrought iron 8-in. pipe to which the mouth- piece was attached. This mouthpiece was a 45 bend enlarging to 12-in., and turned down so as to rest on the mud. The dis- charge pipe from the pump to the embankment was 10-in., and the remaining pipe that carried the dredged material over the embankment was 8-in. Fully 10% of solid matter was carried. The lift was from 16 to 18 ft., the suction about 7 ft. About 55,000 cu. yd. were dredged at an operating cost of about 10 ct. per cu. yd., or a total cost, including the^cost of equipment, of 25 ct. Cost at Wilmington, Cal. Engineering Xews, Aug. 16, 1906, gives the following: A hydraulic dredge was used in the harbor of Wilmington, Cal. The dredge was placed in commission Apr. 1, 1905, and from that time until June 30, 1905 (3 mos.) it dredged 227,464 cu. yd. of sand with shells and a small per- centage of clay, cobbles, disintegrated sandstone and very com- pact and hard mud. The dredge was laid up 16 days during this period, leaving an actual working period of 2.5 months. The rate of dredging was therefore 91,000 cu. yd. per month. The cost of the work during this period was as follows: i,r% 738 HANDBOOK OF EARTH EXCAVATION Routine office work, labor $ 673 Care of plant and property, labor 180 Surveys, labor and supplies 156 Towing, dispatch work, labor, fuel, supplies 316 Alterations and repairs : supt., labor, fuel, water, lubricants, supplies 10,085 Deterioration of plant and property (estimated) 2,264 Total $16,106 The original cost of this dredging plant was as follows: 20-in. suction dredge. " San Pedro " 600 hp. engines $ 99,453 Gasoline launch, 30 ft. long, 16 hp. engine 1,733 Discharge pipe line 3,023 Rubber sleeves 1,275 24 pontoons; 1 water boat, 34 ft. long; 1 oil boat 34 ft. long ; 1 derrick boat 29.5 x 11 ft 6,501 Skiffs . 154 Total cost of plant $112,139 Hydraulic Dredging on N. Y. Barge Canal. The following data of the cost of certain work on contract No. 4 of the New York State Barge Canal, are given by Emile Low in Engineering News, Dec. 5, 1907: This work was performed by means of an hydraulic dredge. The depths of cutting ranged from 15 to 25 ft., the spoil banks being on the sides of the canal. The dredge Oneida had a hull 97x17.5x10 ft. in size and a light draft of 5.5 ft. The suction pipes were two in number, and each was 19.25 in. diameter. The cutters were operated by two independent, compound, vertical, reversing engines of 21 hp. The main engines were of 750 hp. The pump was centrif- ugal in type with a runner 6.5 ft. in diameter. Steam was fur- nished by two boilers working at 200-lb. pressure. The discharge pipe was 26-in. The machine is illustrated in Fig. 14. The dredge as illustrated was not entirely stable and it was necessary to add a pontoon 6 ft. wide to each side. In the beginning of Oct., 1906, one daily shift of 8 hr. was woked, and later two daily shifts of 8 hr. each were worked. In Nov., 1906, three shifts of 8 hr. each were worked. The working force per shift was as follows: Per month 1 operator $100 1 engineman 100 1 engineman 80 3 firemen @ $70 210 1 spudman 60 1 oiler 50 4 ditch hands @ $50 200 In addition a gang was employed to shift the discharge pipe and repair the levees surrounding the spoil banks. There is also a night watchman and an engineman with a gasoline launch. METHODS AND COST OF DREDGING 739 740 HANDBOOK OF EARTH EXCAVATION Much difficulty was experienced in building the levees on ac- count of the numerous windings of the stream, which necessitated the construction of bridges over which the excavator was trans- ported. The cost for the labor employed during October and No- vember is given below. As high as 10,000 cu. yd. of quicksand were pumped in 24 hr., and some 12,000 to 17,000 cu. vd. of other material were removed in the same period of time. Chief engineman, 55 days at $150 per month $ 288.88 Chief operator, 55 days at $135 per month 260.00 Engineman, 129 days at $100 per month 445.93 Engineman, 129 days at $80 per month 356.74 Operators, 4 days at $130 per month 19.26 Operators, 125 days at $100 per month 431.11 Firemen, 387 days at $70 per month 936.44 Spudmen, 129 days at $60 per month 267.55 Oilers, 125 days at $50 per month 215.55 Deck hands, 516 days at $50 per month 891.84 Foremen, 58.4 days at $2 per day 116.75 Foremen, 34.3 days at $3 per day 102.75 Laborers, 1,277 days at $1.60 per day 2,043.20 Tug enginemen, 30 days at $80 per month 80.00 Night watchman, 30 days at $1.60 per day 48.00 Total for two months $6,504.00 Cu. yd. dredged '. 183,055 Cost per cu. yd 3.55 ct. Filling Park Land by Dredging at Chicago. Engineering and Contracting, Feb. 22, 1911, gives the following: The work of increasing the area of Lincoln Park, Chicago, by means of filling in the submerged lands along the shore of Lake Michigan from Diversey Parkway northward, and creating an ad- dition to the present park of 197.54 acres. The 30-in. hydraulic dredge Francis T. Simmons was purchased in 1907 for the work of making the fill. It has now been in operation four seasons and has made about 1,800,000 cu. yd. of fill, making a total of 68 acres of new land. The dredge is of the open end type. The hull is of steel and is 148 ft. long by 38 ft. wide, by 101^ ft. deep. The main pump has 30-in. suction and discharge and the main engines are of triple expansion marine type of 1,200 i." hp. There are two double ended marine boilers 11 ft. 6 in. x 18 ft. long with 8 cor- rugated furnaces. These were fitted at the beginning of last season with eight Jones Underfeed stokers which have eliminated the complaints formerly made on account of the smoke and have brought about a more efficient combustion. The installation of engine room auxiliaries includes condenser, independent air pump, independent circulating pump, fire and bilge pumps, and an elec- tric light outfit. The condenser is of sufficient size to receive the exhaust steam from the cutter engines as well as from the main METHODS AND COST OF DREDGING 741 engines and all auxiliary engines. The rotary cutter is of a type adapted to hard and clay material capable of penetration with a pick, and can handle soft and sticky clay without clog- ging. The cutting edges are of hard steel and are removable. These will probably be changed before beginning next season's work as they have now worn down after two seasons' service. It is likely that manganese steel will be substituted. The dredge is anchored by heavy spuds operated by power. One of the spuds is used as a pivot about which the dredge makes a radial cut 175 ft. wide at one time. The maximum depth of the cut is 35 ft. The dredge is provided with a complete repair shop and with living quarters for the crew. See Engineering and Contracting, Dec. 5, 1907, for the design of the dredge. Considerable comment was made upon the use of a hydraulic dredge in Lake Michigan when this work was started, because it was predicted that it would be impossible to maintain a flexible discharge pipe line in the waves, and that more time would be lost on account of the weather than is the case with other types of dredges. As a mat- ter of fact the proposition has been reversed and with the im- proved design of the discharge pipe, the dredge suffers less delay on account of weather than a barge loading dredge. Pipe Line. The form of pipe line adopted (Fig. 15) is that of a central conduit, 30 in. in diameter carried by two cylindrical air chambers 33 in. in diameter, the three being rigidly held together by the frame. In this way no bolts or rivets are put into the air chambers and they may readily be taken apart. The sections are 95 ft. long, it having been found that shorter sec- tions did not operate in a rough sea as well as the longer ones. The connections between the sections of discharge pipe are joined with the usual rubber sleeve, but the pontoons are connected with an arrangement which embodies the ball-and-socket prin- ciple, not in the pipe itself, but in a strong, steel frame above the pipe. This has proved entirely successful and the practical re- sult is that the dredge is capable of continuing at work in all but the heaviest weather. The ball end of the joint is solidly bolted to the wood frames on the pipe, while "the socket end is fitted to slide in a casing or frame and its movement is resisted by springs, as shown. These springs are heavy car springs, and are two in number. The springs are carried between spring plates in such a manner that they are compressed for either thrust or pull of the drawbar, the whole arrangement is built in the very strongest manner of steel, and each point is strong enough vertically to carry half the weight of an entire pontoon upon it. In other words, should the entire buoyancy be removed from one pontoon for 50 ft. of its length by the trough of a wave, its 742 HANDBOOK OF EARTH EXCAVATION weight would be supported upon the adjoining pontoon with safety. In order to provide flexibility of the pipe at the point of leav- ing the dredge, a swivel elbow is employed and the first length of pipe is short and connected to the elbow by a pair of hinges. The axis of the hinges is horizontal while that of the swivel elbow is vertical; thus the movement of the pipe is universal. The pipe leaves the dredge at the corner in order to permit the pipe to radiate from the dredge at any angle through three-fourths of a circle. The horizontal hinges at the swivel elbow will permit the main pontoons to have a vertical or wave movement of 4 ft. The pipe is attached at one end, to the dredge, and at the land end to a terminal scow which is fitted with a steam winch, by which its own anchorage is controlled. This detail of passing the discharge line onto the land has been worked out in the practice of the last two years so that it is expected in the coming season to profit by the results. The method devised for future use is to anchor the terminal scow at the farthest point of fill, and, as the fill is made, to back the terminal scow away, thus eliminating the use of shore pipe entirely, the stopping of the dredge, and preventing a loss of time due to adding shore pipe. The length of the overhang of the discharge pipe beyond the terminal scow has been made 60 ft. in place of 30 ft. This change was made to prevent the scow from grounding on material flowing back under it from the discharge, a trouble which has previously caused some loss of time. Experiments were made of passing a pipe through the breakwater, as this was a more direct line from the dredge to the fill when the dredge was working in the open lake. At first the terminal scow was tied up to the breakwater and connected to the land pipe. This was found to be unsatis- factory because the scow was too easily affected by the wave ac- tion and was endangered by constantly bumping against the break- water. A scheme was evolved by which the scow was done away with entirely, and the pontoons were connected directly to the pipe projecting through the breakwater from the land side. The first floating pontoon was guyed to the breakwater from the far end, enough slack in the cables being allowed to permit the pon- toon to take a reasonable angle to its connection. The cables were fastened together at the middle with a special clip which could be loosed with one blow of a small bar so that a quick release could be obtained in case of necessity. At the time of exceedingly rough weather the dredge with its trailing pontoons could then be towed safely and easily into the harbor. It is thus seen that the difficulties attending dredging work are METHODS AND COST OF DREDGING 743 744 HANDBOOK OF EARTH EXCAVATION much greater for work on the Great Lakes than for work on smaller lakes or upon other inland waters. The time lost on ac- count of weather is less than by a scow loading dredge because such dredges are compelled to stop work when the sea becomes only so rough as to cause hard bumping between the scow and dredge. The time lost by the Francis T. Simmons on account of weather during the past dredging season of 7 mos., has averaged 18.2%. In 1909 the average was 9%, in 1908, 14.4%, and'in 1907 it was 23.2%. During the 1910 season (Apr. to Oct. inclusive), there were 4,320 working hr., of which 60.2% was spent in pump- ing, and 39.8% lost. The following record for September is typical : TIME LOST BY DELAYS September, 1910 Hr. Total available time 600 Dredge worked 381 Delays 219 Weather 57 Short pipe 32 Suction pipe, pumping and plug 11 Pontoon line 32 Swinging cables 15 Main engine 24 Spud engine ^ Cutter engine Cutter shaft Moving dredge to new cut 5 Towing and preparation 34 Miscellaneous 1 Stones 7 During the month of September the dredge worked 11 days from a position outside the breakwater protection and 11 days in the yacht harbor. The balance of the time was taken up by bad weather, Sundays and holidays* The cost of the work for the season of 1910 is shown below. The items of tug service are calculated at actual cost per hr. of service. The cost of operation of the tugs and other aux- iliary machinery is given later. During the season of 1910, the total yardage was 570,243, the dredge being in commission 4,320 hr., and the cost was as follows : Operation: Per cu. yd. Labor $0.0243 Fuel 0300 Supplies, tools, sleeves, , etc 0076 Commissary labor and supplies 0104 Field repairs, labor and material 0106 Tug service 0238 Derrick service 000;i Motor boat 0010 Insurance uuou METHODS AND COST OF DREDGING 745 Winter repairs and fitting up: Labor 0093 Material 0037 Fuel commissary and tools 0018 Tug service 0013 Totals Operation 1142 Repairs .0161 Operation and repairs $0.1303 The repairs shown with the operating expenses include the minor repairs made during operation, which those shown under the head of winter repairs are for repairs made during the win- ter season in preparation for the work of the summer of 1910. Some of the field repairs included the relining of several pon- toon discharge pipes. This -work costs about $225 per pontoon, $125 for material and $100 for labor. The pipe is relined with a strip of %-in. sheet steel, 36 in. in width, placed in the bottom of the pontoon to fit the circumference. The pontoons are 95 ft. long. When relined they are expected to last three of four sea- sons. The winter repairs consisted of overhauling the engines, boilers, furnaces, stokers, and replacing steam pipe connections. The engines were relined, the shafts rebabitted and rebushed. The heaviest wear, however, is on the cutter mechanism. The cutter ran two years without renewal of blades. The next blades put in, however, will probably be of manganese steel and are ex- pected to last longer. The centrifugal pump runner lasts about two seasons and costs $600. It is of cast steel with a steel lin- ing on the blades. The other repairs consist of cleaning and scraping the steel hull and painting. Table I is a summary of the costs and performance of the dredge for the past four seasons, or since the dredge was built. It must be noted here that the yardage as given for the years 1907-8 and 9 was calculated from the cut, while that for 1910 has been calculated from the total amount in place. For this reason the season of 1910, which is believed to have been the best season's work yet done, does not show well in the comparison. The operating crew of the dredge is as follows: Per month 1 chief operator $150.00 1 assistant operator 125.00 1 chief engineman 150.00 1 assistant chief engineman 110.00 4 oilers 66.00 4 firemen 66.00 4 coal passers , 55.00 2 spudmen 66.00 1 janitor 55.00 8 deckhands 55.00 746 HANDBOOK OF EARTH EXCAVATION s. & ;SS ** : * - _ a 2 c c :fl^2 :r :" .2.2 * -* Tl hr . ^* -*^* ** i!wl ; iff M M P4 M H a rri fffliillfll ? METHODS AND COST OF DREDGING 747 Commissary : 1 steward 86.00 1 second cook 40.00 1 porter 40.00 The men receive their board in addition to the wages listed. They work two 12-hr, shifts. For overtime they are paid time- and-a-half and if worked Sundays (which is extremely seldom), they get double time. All overtime is paid for in addition to and not considering their regular wage. This is in accordance with the union rules on the great lakes. The dredge is working in very stiff gumbo clay which is cov- ered with a layer of from 3 to 5 ft. of sand. The depth of the dredging at Chicago is from 18 to 35 ft. and the material was deposited through about 2,000 ft. of pipe. Cost of Dredge. The following table gives the list of items which together make up the cost of the dredge as it was put in operation in 1910: Engineering, plans, inspection, etc $ 9,816.45 Contract (1907) with 2.000 ft. pontoons 151,402.19 Terminal pontoon scow (1907) 1,227.88 8 Jones underfeed stokers (1908) 6,700.00 6 pontoons (1908) 10,485.00 Miscellaneous 874.04 Total $180,505.56 Cost of Tenders. In connection with the dredging work and other construction tributary to the Park Extension work, a fleet of tugs, derricks and other floating apparatus was employed. The cost of operation of each of these for the past year is given below, together with the original cost, maintenance cost, and a brief de- scription of the apparatus. The tug Keystone has a steel hull, 87^ ft. long, 19 ft. beam, and 11 ft. deep. She is of 94 gross ton weight, and was built in 1891. She contains 1 fore and aft compound condensing engine with 18x34-in. cylinders of 30 in. stroke, and S Service of other plant ............................... ! i Total repairs ................................ $2.602.32 Total operation and repairs Total cost per hr The tug Hausler was built in 1893 of wood and was purchased for its present work in 1908 for $10,500. She is rated at 61 gross tons and is equipped with one vertical non-condensing en- METHOD AND COST OF DREDGING 761 gine, 22 x 44 in., 24-in. stroke. She has one fire box marine boiler, 14 ft. long by t)6-in. diameter, and carries 135 Ib. of steam. The other tugs each carry 125 Ib. of steam. TABLE III. OPERATION AND REPAIRS TUG " HAUSLER " In commission 5,730 hours Operation : Totals Labor $ 9,532.94 Fuel 3,464.30 Supplies 1,112.14 Insurance 288.25 ^ . Total $14,397.63 Repairs : Labor $ 1,628.05 Material 1,692.74 Service of other plant 151.57 Totals $ 3,472.36 Total operation and repairs 17,869.99 Total cost per hr 3.12 Pile driver No. 1 is a floating driver which was used for constructing breakwater. This piece of plant was in commission 878 hr. and Table IV shows the expense incurred. TABLE IV. OPERATION AND REPAIRS PILE DRIVER NO. I In commission 848 hours Operation : Totals Labor $ 4,601.92 Fuel 176.59 Supplies 217.37 Insurance 97.00 Total $ 5,092.88 Repairs : Labor $ 1,255.20 Material 239.72 Service of other plant 76.32 Total repairs *. . $ 1,571.24 Total operation and repairs ? 6,664.12 Total cost per hr 7.59 n.%r/ o No TABLE V. OPERATION AND REPAIRS PILE DRIVER NO. 2 In commission 717 hours Operation : Totals Labor $ 3,809.62 Fuel 127.30 Supplies 163.08 Insurance 97.00 Total operation $ 4,197.00 762 HANDBOOK OF EARTH EXCAVATION Repairs : Labor $ 1,121.55 Material 183.94 Service of other plant 107.83 Total repairs $ 1,413.32 Total operation and repairs $ 5,610.32 Total cost per hr 7.82 The cost of the season's vork of Pile Driver No. 2 is shown in Table V. The derrick was in commission 1,910 hr. and served to handle stone from barges, and for handling materials on all parts of the work. The cost for the season is shown in Table VI. TABLE VI. OPERATION AND REPAIRS TO DERRICK In commission 691 hours crew of 2 men In commission 200 hours crew of 4 men In commission 1,019 hours crew of 6 men (,.'; Operation : Total Labor, watching $ 321.67 Fuel 288.06 Supplies 226.31 Insurance 22.00 Total $ 798.04 Repairs : Labor $ 345.60 Material 236.93 Total $ 582.53 Total operation and repairs : Except operating labor '. . . $1,380 57 Total with 2 men 691 hr 771.13 Total with 4 men 200 hr 502.70 Total with 6 men 1,019 hr 3,391.87 The motor boat which served all the work was in commission eight months. This boat was purchased by the Park Commission in 1907 for $1,150. Its cost for the season is shown in Table VII. TABLE VII. COST OF* OPERATING MOTOR BOAT Operation : Totals Labor operating $ 496.10 Labor watching 80.42 Supplies 546.91 Total $1,123.43 Cost per day 4.68 METHODS AND COST OF DREDGING 763 Repairs : Labor $ 247.95 Material 299.05 Tug and derrick 35.16 Total | 582.16 Total operation and repairs ". . $1,705.59 Cost per day 2.42 Total operation and repairs per day 7.10 Method of Measuring the Displacement of Material in Scow Barges. A method of measuring materials delivered on deck scows, described by Mr. Howard J. Cole in the Journal of the American Society of Engineering Contractors, is given in En- gineering and Contracting, May 1, 1912, as follows: The exact dimensions of the scow were measured by steel tape and the point A' plumbed up from A, see Fig. 18, similarly B', B" and A" were obtained, and the distance A' B',' A" B", A.' A" ___ . Fig. 18. Displacement Diagram of a Scow Barge. and B' B" likewise measured by steel tape; the depths A A' and B B' and corresponding depths on the other side of the boat were carefully measured by a graduated rule and noted on a sketch of the boat. When the latter was empty the point C' was plumbed up from (7, D' from D, and again on the further side, and the four dimensions corresponding to the loaded meas- urements recorded. From a comparison of the depths (light and loaded), and with the complete measurements taken, the dis- placement was computed as hereafter shown. The length A' B' and A' A", and the other two corresponding measurements were obtained direct on the scow deck, and the depths were obtained by taking the difference between the read- ings loaded and light and the displacement thus figured. By averaging the lengths A' B' and A" B" and multiplying by the width A' A", also averaging the lengths C' D' and C" D" and multiplying by the width C' C" and multiplying the average of these two by an average of the differences between the load lines (C" C A' A, etc.) at the four corners, the cubic feet of displacement is obtained, which multiplied by 62.5 and divided by 2,000, gives the displacement in net tons. 7fi4 HANDBOOK OF EARTH EXCAVATION This can be expressed in a simpler manner as follows: Area of boat Area of boat loaded water lines + light water lines distance X between the X two planes 62.5 =: Displacement 2,000 in tons. Bibliography. " Hand Book of Construction Plant," R. T. Dana. " Excavating Machinery," A. B. McDaniel. " Earth and Rock Excavation," Charles Prelini. "The United States Public Works," W. M. Black. " Hydraulic and Placer Mining," Wilson. " Improvement of Rivers," Vol. I, B. F. Thomas and D. A. W T att. " Dredges and Dredging," Charles Prelini. Government Dredging. Some Data on Dredging Bars in the Columbia River, Engineering and Contracting, August 21, 1912. Results of Operation of Seven Bucket Dredges in U. S. River and Harbor Improvement in 1912, Eng. and Con., July 16, 1913. Cost ofJExcavating 4,151,000 cu. yd. of Material with 51 Dipper and Bucket Dredges in 1911, Eng. and Con., Oct. 16, 1912. Records and Cost of Work of Dipper Dredges Operated by the U. S. Engineers in River and Harbor Improvement, 1911-1912, Eng. and Con., Aug. 13, 1913. Cost of Dredging 32,000,000 cu. yd of Material With Sea-Going Government Dredges in 1911, Eng. and Con., Sept. 25, 1912. Cost of Dredging 29,708,465 cu. yd. of Material with 24 Seagoing Hopper Dredges During 1912, Eng. and Con., April 30, 1913. Methods and Costs of Operating Hydraulic Pipe Line Dredges on the Upper Mississippi River, Eng. and Con., Sept. 24, 1913. Dredges and Dredging in Mobile Harbor, Alabama ; Records and Cost of Dredging Work, Engineer- ing and Contracting, March 20, 1912. Cost of Dredging 21,016,- 512 cu. yd. of Material with 38 Hydraulic Pipe Line Dredges During 1912, Eng. and Con., April 23, 1913. Cost of Dredging 20,000,000 cu. yd. of Material in 1911 with 39 Hydraulic Pipe Line Dredges, Eng. and Con., Oct. 9, 1912. Gold Dredging. *' Gold Dredging in California," Report of State Minerologist, Lewis E. Aubury. The California Gold Dredge, Robert E. Cranston, Eng. and Min. Jour., March 9, 1912. Method and Cost of Gold Dredging by the Elevator Bucket, Eng. and Con., Nov. 4, 1908. Some Costs of Gold Dredging and Records of Dredge Operation of Interest to Dredg- ing Contractors, Eng. and Con., Nov. 16. 1910. Recent Exam- ples of California Gold Dredges with Costs of Dredging, Eng. and Con., Apr. 12, 1912. Notes on Dredging and Its Cost in British METHODS AND COST OF DREDGING 765 Guiana, Eng. and Con., Sept. 21, 1910. Cost of Electrical Power for Dredges, Eng. and Con., Jan. 10, 1912. Methods of Restor- ing Soil on Dredged Areas and Cost of Gold Dredging in Aus- tralia, Eng and Con., March 13, 1912. Cost of Dredging and Hydraulic Excavation in Australia, Eng. and Con., July 10, 1912. Some Dredging Costs Based on Actual Dredging Experience, Eng. and Con., Sept. 20, 1916. Jbiinoi *d CHAPTER XVI METHODS AND COST OF TRENCHING The words trench and ditch are often used synonymously, but as treated here each word has a distinct meaning. Trenches are long and comparatively narrow excavations in the ground that are partly or entirely refilled with pipes, conduits, or masonry, or are backfilled with the excavated soil or other suitable back- filling material. Ditches are similar excavations that are left open after being dug for the purpose of carrying or holding water. The methods and cost of constructing them are treated in Chap- ter XVII. Wide ditches are often called canals. Tranches are dug for sewers, water pipes, and conduits, and for foundations of retaining walls and similar structures. The main items of work in trenching are (1) excavation, (2) sheeting (in trenches in caving ground), (3) pumping (in wet soil), (4) pipe laying, and (5) backfill. The fourth item does not strictly belong under the head of excavation. However, in pipe sewer trenches, the last one or two feet (in depth) of trench are generally dug by the pipe layers and is thrown back on the pipe already laid. Thus, as cost records are often kept, a small part of the cost of sewer trenching is included under pipe laying. In water pipe work, the trench is generally dug com- pletely except for the bell holes before the pipe is laid. Bell holes are usually excavated after the pipe has been laid in the trench. In conduit construction the earth is almost invariably excavated entirely before the conduits are laid. References. In my " Handbook of Cost Data " will be found methods and detailed cost of trenching for water pipe and sewers, accompanied by costs of pipe laying, etc. Excavation by Hand. Hand excavation is the most common method of digging trenches but there are many cases in which hand work is resorted to where machine excavation would pay handsomely. In trenches up to 6 or 8 ft. in depth the material is first shoveled from the trench to the surface, and then, as the spoil pile grows larger, it must be shoveled away from the edge of the trench. A good foreman will see that the material from the first few feet of trench is thrown far away from the edge. At- tention to this matter will often eliminate a second handling of the excavated material. The distance from the trench at which the first portion of the spoil must be thrown may be approx- imately determined by multiplying the height of the trench by its width and dividing by 2. In trenches from about 6 to 12 ft. deep the material must first be thrown to a staging, thence to the surface, and finally shoveled back from the edge of the trench, 766 METHODS AND COST OF TRENCHING 767 thus being handled three times. In trenches 12 to 18 ft. deep the material must be handled four times. The earth from trenches of greater depths should not ordinarily be removed on stages but should be handled in buckets by a derrick or other machine. Methods of Excavating Trenches by Hand. Engineering and Contracting, June 2, 1909, gives the following: Men should never be placed indiscriminately at work in a trench. After opening a section of a trench, especially where there is water, the most rapid digger should be placed first, then the next best and so on down the line. This will allow the water to run towards the lowest part of the trench and one set of pumps will suffice to handle it, as well as let the timbering or shoring be carried on in its regular order. If the men were placed indiscriminately the better men would carry their sections to a greater depth quicker than the poorer workmen, causing the water to settle in their pits, thus impeding the work and in- creasing the cost. There are several methods of placing the men at work in a trench. The most common one is to have the men spaced only a few feet apart so that the foreman can watch them. Some- times a certain number of men are detailed to do the picking while the rest are shoveling. This arrangement cannot be recom- mended, especially in narrow trenches, as the pickers often in- terfere with the shovelers, and in moving from place to place the pickers tramp over the loosened earth and compact it. At times a shoveler will be kept waiting for a man to do his picking. The better way is to let each man do his own picking and shoveling, unless the trench is wide enough for two men to work side by side, then, one man will loosen the earth, taking only a part of his time for this, and the rest of his time will be used up in shoveling. The men will also alternate on picking, thus " spell- ing " themselves, without loss of time. The advantages claimed for this method of spacing men in a trench are ( 1 ) that the foreman can watch the men easier than when they are scattered, and (2) that the follow up work, such as laying pipe, can be kept close to the men excavating, thus keeping the amount of open trench at a minimum. The first reason should not be given consideration. The second reason is often a valid one. However, by reducing the number of men in the excavating gang, and increasing the amount of work done by each man, this can be overcome. This brings us to con- sideration of a second method of spacing men in a trench. The trench or ditch is staked off in sections, according to its width and depth, 25 or 50 ft. long. These sections should al- 768 HANDBOOK OF EARTH EXCAVATION ways be short enough to be finished in a day, as it has a good effect on a man to complete a task in a day and not have to start on an old job the next morning. Then, too, in case of rain at night, the water can drain to the low part of the trench. By this method one man does his own picking and shoveling and he cannot interfere with another man's work. In a wide trench or ditch two men can be placed in a section to work side by side, or with a narrow trench a long section can be given to two men, the men working from each end of the section towards the center. Men working in pairs generally do better work than when working alone. The slow man will try to keep up with the faster man's pace, or if each work at the same rate, each spurs the other on to increased efforts. In working men in sections, a stake should be driven at the end of each section and numbered, as 1, 2, 3, and so on. Each section should be of the same length, or contain the same yard- age. This permits a record to be kept of each man's work, or if the men are working in pairs, of each team's work. Then the number of cubic yards excavated by each man is known for each day's work. By this method it will be found that in a trench not over 4 or 5 ft. deep a man will average 10 to 12 cu. yd. in a 10-hr, day, while by the other method a man will seldom excavate over 8 or 10 cu. yd. This method can be effectively applied where the men are paid a bonus for yardage in excess of a specified daily amount. Another method of placing men in a trench is to have one man excavating the first 12 or 15 in., with another man fol- lowing taking out another layer, and so on down in layers until the total depth is obtained. The advantages claimed for this method are that the men do not interfere with one another, the amount of trench kept open is reduced to a minimum, and no matter at what time a rain occurs, the water will always run to the lowest point in tlie trench. However, this method, like the one first described, makes it difficult to obtain the best work from the men, and the same advantages can be obtained by the second method described. Excavating a trench by layers in successive steps is to be com- mended, but in using the second method of spacing men in a trench, and giving them sections to take out, this method of dig- ging a trench by stepping it down can be adopted for each sec- tion. Fig. 1 shows a longitudinal section of a trench to be 5 ft. deep and illustrates how it can be carried down in steps. It is evident that a man working by this method always has a small breast, both to pick and shovel against, except when he METHODS AND COST OF TRENCHING 769 starts his section, where for a short time he must pick and shovel from the top. With a small breast he throws down more dirt with his pick and he also gets a much larger shovelful, as he throws the dirt out. Then, too, stepping from one step to another and casting the material out from different depths rests r -.j'0" -- Fig. 1. Longitudinal Section of a Trench Showing Method of Excavating It in Successive Steps the man without his stopping work. With this method, if it raina the water all goes to the bottom of the trench, where it can be quickly pumped out of each section. Tools for Hand Trenching. Except in very shallow trenches or ditches, or in confined places where the action of a man is interfered with by the sides of the trench or by braces, a long handled shovel should be used. The workman not only conserves his energy because he does not bend down so often or so far, but he is able to cast the earth higher and farther than with a short- handled shovel. In sand or other easy soil a square edged shovel should be used. In firm soil or loam and in hard, compact earth or gravel, a round pointed shovel is preferred, but in clay a spade is far more efficient. A shovel holds a greater quantity of loose material than a spade, but clay generally holds together well and as great a quantity is held on a spade as on a shovel. The spade, moreover, is stronger and easier, to drive into firm clay. For loosening the material a pick and not a mattock should be used. With a pick a much larger amount of material is loos- ened at each blow. A pick breaks out a pyramid while a mat- tock breaks out a truncated pyramid and one of smaller base and altitude. In the stiff Chicago clays a draw knife is often used to shave off pieces. In a stiff clay this is a more efficient tool than is either a pick or a mattock. In trenches the men should be prevented from dressing the sides of the trench. If given a mattock an Italian will trim the sides until they look as if sandpapered. Cost of Digging Trenches by Hand on Long Island. The ma- terial in general consisted of 1 it. of topsoil, 3 ft. of hard packed 770 HANDBOOK OF EARTH EXCAVATION clay requiring picking, and the remainder of fine sand and gravel. Nests of stones, averaging 1 ft. in diameter, were sometimes encountered. After the trench had passed a depth of 4 ft. a man was stationed on the bank to cast back the earth shoveled out by the bottom men. At a depth of 6 or 7 ft. a staging was gener- ally required, and after passing a depth of 12 ft. a second staging was necessary. For slight depths the trench was braced with vertical plank held apart by Dunn braces, but when sand was reached sheeting was required. Stones were removed by a chain- hoist and small tripod. The last foot of trench was dug by the pipe layer and charged to pipe laying. The wages paid were as follows: Foremen, $4.00 per 10-hr, day; laborers, 17 ct. per hr.; waterboy, $1 per day. A proportion of the wages of foremen and Waterboys is charged to the excavation. The following costs give the results of 48 time studies. From these observations it was found that in 10 hr. one man will excavate 9.23 cu. yd. in trenches up to 6 ft. in depth; 7.37 cu. yd. in trenches 6 to 12 ft. deep; and 6.38 cu. yd. in trenches 12 to 18 ft. deep. Victor Windett, in Engineering and Contracting, June, 1911, states that one man dug 10.5 cu. yd. per day in trenches (in Indiana) up to 6 ft. deep; 7.2 cu. yd. per day in trenches 6 to 12 ft. deep; 3.7 cu. yd. in trenches 12 to 18 ft. deep; and 2.6 cu. yd. in deeper trenches. It would appear that pumping was re- quired in all of the deeper trenches recorded by Mr. Windett, and this probably accounts for the low output at depths over 12 ft. On the Long Island work no pumping was required. The costs are given in the following table: TABLE Cost of Hand Dug Trenches; Depths up to 6 ft.; Material Handled Twice Cost per cu. yd 20.9 ct. Cost per lin. ft 11.4 ct. Average cut 5ft. 4 in. Average width 33 in. Average No. of men in gang 10.3 Cost of Hand Dug Trenches; Depths 6 to 12 ft.; Material Handled Three Times Cost per cu. yd 24.8 ct. Cost per lin. ft '. 21.8 ct. Average cut . 8 ft. 3 in. Average width 34.4 in. Average No. of men in gang 12.3 Cost of Hand Dug Trenches; Depths 12 to 18 ft.; Material Handled Four Times Cost per cu. yd 28.2 ct. Cost per lin. ft 46.8 ct. Average cut 14.11 ft. Average width 36 in. Average No. of men in gang 14.3 METHODS AND COST OF TRENCHING 771 A Platform for Retaining Earth, from Trenches. In a paper road before the American Railway Master Mechanics Association (1894) R. C. P. Coggeshall described a portable platform used to hold the earth from trenches. This platform consisted of ^-in. spruce boards secured to 3 x 4-in. joists. It was in two sections, each 6x12 ft., hinged so that one was horizontal and the other vertical, held in position by braces. This platform caused the laborers to take greater care when throwing up the earth so that it needed no rehandling, and also obviated the necessity of trimming the back slope to permit vehicles to pass. In backfilling, a certain amount of earth could be dumped by lift- ing the platform. Experiments on two 300-ft. lengths of 8-in. pipe trench, 5 ft. deep, showed that the cost of trenching, in- cluding cartage, with the platform was 14.7 ct. per lin. ft., and without it, 19.3 ct., a saving of 24%. Cost of Sewer Trenches. J. G. Palmer gives the following cost data in Engineering News, June 25, 1908: A sewer was built in 1905 from the new laboratories of the U. S. Dept. of Agriculture, Washington, D. C., across the mall to the public sewer at 13th St. The work was done by day labor (negroes) who are said to have been efficient and well man- aged, but it will be noted that they were excessively managed, for the item of " general expense " was inordinately high. The trench was 3 ft. wide, except at manholes where the exca- vation was 6 ft. square. The ground was 10 ft. of clay, under which was 10 ft. of fine sand and loam, and below that was coarse gravel containing many boulders of " one man " size. No water was encountered. All excavation was done with picks and shovels. The trench was braced with screw jacks between 2 x 12-in. planks placed horizontally, and spaced 2 ft. c. to c. below the clay. The labor of bracing is included in the item of excavating. An eight hour day was worked. The first section was 8.7 ft. deep, 3 ft. wide, 820 ft. long, and contained 4 manholes. The cost of the trenching was: Per cu. yd. Excavation, laborers at $1.50 $0.50 Lumber at $18 per M 0.08 Tools ($50) 0.06 Total $0.64 General Expense: Foreman, at $5.00 $0.12 Clerk, at $1.50 0.04 Watchman, at $1.50 0.04 Waterboy, at $1.00 0.01 Carpenter 0.02 Total general expenses $0.23 Grand total $0.87 772 HANDBOOK OF EARTH EXCAVATION It will be noted that there was about 1 cu. yd. of excavation per lin. ft. of trench. The second section was 23.5 ft. deep, 3 ft. wide, 838 ft. long, and contained 4 manholes. The cost was: Per cu. yd. Excavation, laborers at $1.50 $0.68 Lumber at $18 per M 0.03 Tools ($50) 0.02 Total $0.73 -' ' '" ' ; '" ,^unbi(i>iiM*l ;: General Expenses: Foreman, at $5.00 $0.08 Clerk 0.03 Watchman 0.03 Waterboy 0.02 Total general expense $0.16 Grand total $0.89 Cost of Trenching, Astoria, Ore. Mr. A. L. Adams states in Transactions American Society of Civil Engineers (1896) that in trenching for the Astoria (Oregon) Waterworks, in 1896, the first contractor averaged only 7 to 8 cu. yd. per man per day. Later on another contractor, even in the rainy season, averaged nearly 10 cu. yd. per man per 10-hr, day of trenching (including backfilling), at a cost (including foreman) of 171/4 ct. per cu. yd., wages being $1.70 a day. The material was yellow clay dug with mattocks and shovels. Cost of Trenching at Holyoke, Mass. Engineering and Con- tracting, Sept. 16, 1908, gives the following account of concrete block sewers that were constructed in Holyoke during 1908, the sewer proper being built by contract and the excavation and backfilling being done by day labor under the direction of the city engineer. This is a very expensive method of constructing small sewers, for two reasons : First, as in all kinds of construction work, day laborers employed by a government are very rarely as effi- cient as men working for a contractor. Second, in construction of this character, where the work of the trenchmen and the masons must be co-ordinated if economical results are to* be ob- tained, it is necessary to have no division of authority or re- sponsibility. By properly performing their respective duties trenchmen can save the masons much labor, and the masons can save much unnecessary trenching. It cannot be disputed that in almost every case there is a stronger incentive for the con- tractor's men to do efficient work than for the city's employees. The following wages were paid for an 8-hr, day: Foreman, per 8-hr $3.50 Laborers, per 8-hr $2.00 METHODS AND COST OF TRENCHING 773 One trench was dug 14 ft. deep and 4.5 ft. wide, through sand and clay not a difficult material. The soil was thrown on the side of the trench and used for backfilling. There were exca- vated from this trench 2.33 cu. yd. per lin. ft. The cost per cu. yd. was $1.21, and the cost per lin. ft. was $2.82. Another trench was 14 ft. deep and about 6 ft. wide, the material being the same as in the first trench. There were 3.11 cu. yd. per lin. ft. The cost of excavating and backfilling was $1.25 per cu. yd., and the cost per lin. ft. was $3.90. Costs at Fredericton, N. B. From information furnished by A. K. Grimmer, City Engineer, and published in Engineering and Contracting, Aug. 25, 1909, the following data are taken re- garding two pipe sewers built in 1908, at Fredericton, N. B. The work was done by day labor. Foremen received 30 ct. per hr. and laborers 18 ct. per hr. A 9-hr, day was worked. Location Waterloo Rd. Phoenix Sq. Length, ft 495 811 Size of pipe, in 8 8 Cut depth, ft 9.7 5.8 Cu. yd. of excavation 533.5 522.5 Cost per cu. yd. excavation $0.515 $0.374 The Waterloo Road sewer trench had to be close sheeted, the material being sand and the bottom 4 ft. wide. The Phoenix Square trench was in sand and loam and had to be braced every 4 to 6 ft. The material was dry. The cost of sheeting and bracing is included in the above costs. Costs of Sewer Work in Baltimore, Md. The following data are from the Annual Report of the city engineer of Baltimore, Md., for 1909. A more complete abstract of this report will be found in Engineering and Contracting, Aug. 3, 1910. COSTS OF EXCAVATION ON VARIOUS SEWERS IN BALTIMORE (For hand excavation except where noted, cost of bracing and backfill is included.) Per cu. yd. Eastern Ave. sewer, 2,928 cu. yd , $1.19 Eastern Ave. sewer, 1,624 cu. yd. (machine excavation) 1.46 Race St. sewer, 662 cu. yd 1.25 Monroe St. sewer, 1,112 cu. yd 1.08 Hollins St. sewer, 129 cu. yd 0.64 Seventh St. sewer, 177 cu. yd 1.36 Singluff Ave. sewer, 209 cu. yd 1.12 University Parkway and Wickford Road drains, 527 cu. yd 0.85 Clifton Park sewer, 961.6 cu. yd 0.93 Cedar Ave. sewer, 732 cu. yd 1.16 Water Main and Conduit Trenches. Trenches for water mains and conduits differ from sewer trenches in that the trench usu- ally has a constant depth, which is relatively shallow. 774 HANDBOOK OF EARTH EXCAVATION Excavating for Electrical Conduits at Baltimore, Md. Chas. E. Phelps, Jr., Chief Engineer of the Baltimore Electrical Com- mission, is authority for the following data given in Engineering and Contracting, Mar. 11, 1908: The figures show the cost of excavation from the inception of the work until June, 1907, a period of nearly 9 years. The cost includes all the labor, both men and teams, timbering drainage, clearing away of obstruction, such as old pipes, etc., and back- filling, but does not include paving. The wages paid to men and teams for an eight-hour day were as follows, foreman, 1899-1903, 37% ct. per hr.; 1903 to 1907, 43% ct. per hr. Gang boss, 31% ct. per hr. Two-horse teams, 1900 and 1901, 37% ct. per hr.; 1901-1903, 405/ ct. per hr. ; 1903 to 1905, 45% ct. per hr.; 1906 and 1907, 50 ct. per hr. One-horse cart used in 1899, 31% ct. per hr. Laborers, 20% ct. per hr. throughout the 9 yr. The excavation work was entirely in earth, which was sand, clay, the debris of filled in ground, and black mud on the streets near the harbor. The trunk lines of the conduits are mostly in the streets or alleys, but many of the distributing ducts are laid under the sidewalks, and frequently on both side of the street. In the low sections of the city many of the trenches had to be underdrained. These ditches needed shoring, likewise those dug through sand. But little timbering was done through the other materials, especially for the distributing ducts, which were uniformly about 3 ft. deep and 2 ft. wide, making about 14 cu. yd. of excavation per lineal foot of trench, including the excava- tion for service and distribution boxes, which are from 60 to 70 ft. apart. The trenches for the trunk lines are from 3 to 12 ft. deep, being on an average of 6 ft. and varying from 2 to 4 ft. in width, or an average of 3 ft. This means an average of 2-3 cu. yd. of excavation per lineal foot of trench, exclusive of manholes. These are so far apart, that the extra excavation will increase the average but little. The per cent, of labor of the total cost varied somewhat for each year, running as low as 81% for the main trunk lines, where much shoring had to be done, and the trenches were wet, up to 97%, where little shoring was needed, averaging 95%. For the distributing lines the per cent, of labor of the total cost of excavation averaged 97%, varying from 94% to 98%. These percentages include labor, both men and teams. It will be noticed that the price paid for teams and also for foremen has increased, yet, with the exception of the year 1903, the cost of excavation has steadily decreased. This, too, in spite of the fact that the amount excavated has decreased. This is due METHODS AND COST OF TRENCHING 775 primarily to the work of every year being farther and farther from the center of the city. In the central district of the city, the excavation is more difficult, owing to the pipes, sewers and other obstructions being larger and more numerous. The cost of excavation also includes the cost of watching, this item being large, on account of the short working day, and the fact that two 8-hr, shifts must be made of the watching. This doubles the cost of this item. Two horse dump wagons are used for hauling the excess ma- terial away from the trench. These wagons are of a nominal capacity of 2 cu. yd., but the average load is about 1^ cu. yd. place measurement. Each team averages five trips to the dump per day, thus hauling 7y 2 cu. yd. All work was done by day labor. The cost per cu. yd. of trench was as follows: 31,097 cu yd. in 1899 $2.61 11,862 cu 7,155 cu 6,559 cu 11,590 cu yd. in 1900 1.87 yd. in 1901 1.88 yd. in 1902 1.82 yd. in 1903 1.94 1,120 cu. yd. in 1904 1.97 15,476 cu. yd. in 1905 1.65 9,984 cu. yd. in 1906 1.53 5,687 cu. yd. in 1907 1.49 ..-'' t_. .' ^^^ Trenching for Tile Drains. The following relates to work on- an extensive scale at the experimental farm of the University of Minnesota. An abstract of a bulletin on this subject is given in Engineering and Contracting, Oct. 21, 1908. The tools used for this work are a skeleton or muck spade for removing the earth. This spade has a blade 18 in. in length, made of three prongs with a solid cutting edge at the lower end. A cut the full length of the blade is taken, the slice of earth cut being comparatively thin. The top of the spade is pushed slightly forward to break the cut loose. It is then raised and the ma- terial thrown out. The loose dirt which falls in the trench,, known as crumbs, is thrown out by a long-ha*ndled, round-pointed shovel. The last cut of the spade reaches to within 2 or 3 in. of the grade line and is just wide enough at the bottom to admit the tile. The bottom is cleaned out and dressed to fit the lower half of the tile with the tile scoop. The tile scoop is a long-handled tool, semi-circular in shape, 16 in. in length and made in sizes to fit the various tile up to 8 in. When over that size the finishing is usually done with the long-handled shovel. The tile scoop is operated by standing in the trench and drawing toward the workman. The bottom of the trench behind this tool is smooth and conforms to the lower half of the tile. In trenching by hand, unless the trench is deep, or. 776 HANDBOOK OF EARTH EXCAVATION the digging hard, two men work together. One takes out the top spading, the other the bottom and finishes the trench. On deep trenches there is usually a man at work on each spading in depth, the trench being carried along in steps. Many tile ditchers throw the excavated earth on both sides of the trench, while others prefer to throw it all on one side; however, this is a matter of little importance in most localities. The contract prices on a certain job involving the laying of 11,430 ft. of tile drain were arrived at in accordance with Fig Forms of Tile Trench on Experimental Farm of the University of Minnesota. the common rule of tile construction, i.e., a fixed price for all trenches averaging 3 ft. or under in depth plus an additional sum for each inch additional average. The average is found by dividing the sum of the cuts at all the stakes by the total num- ber of stakes. In this case the price was 40 ct. per rod for 3-ft. work, then 1 ct. for each additional inch up to 4 ft. work, then 2 ct. per inch for each additional inch. This gives prices for various depths as follows (cost of trenching, laying tile, and blinding, included) : 3-ft. trenching, 40 ct. per rod or $2.42 per 100 ft. 3.5-ft. trenching, 46 ct. per rod or $2.79 per 100 ft. 4-ft. trenching, 52 ct. per rod or $3.15 per 100 ft. 4.5-ft. trenching 64 ct. per rod or $3.88 per 100 ft. 5-ft. trenching, 76 ct. per rod or $4.60 per 100 ft. METHODS AND COST OF TRENCHING 777 The average work done by one man per day was 100 ft. of 3-ft. trench; 95 ft. of 3^-ft. trench, and 80 ft. of 5-ft. trench. Un- skilled labor cost the contractor $2 per day. The cost of backfilling tile trenches by hand was as follows per 100 ft. Trench 4.5 ft. deep, 3.75 hr. at 20 ct. per hr $0.75 Trench 3.0 ft. deep, 2.8 hr. at 20 ct, per hr 56 Trench 2.0 ft. deep, 2.0 hr. at 20 ct. per hr 40 The cost of backfilling by dragscraper was: Team with driver 55 min. at 45 ct. per hr $0.42 Scraper holder, 55 min. at 20 ct. per hr 18 Total per 100 ft., trench 3.5 ft. deep $0.60 The cost of filling 100 ft. of trench with grader was: Two teams with drivers on plow, 6 min. each at 45 ct. an hr $0.090 1 man to hold plow, 6 min. at 20 ct. an hr 0.020 Total per 100 ft $0.110 The cost of backfilling 100 ft. of trench with a plow was as follows : 2 teams with drivers on grader, 10 min. each at 45 ct. an hr $0.150 1 man operating grader, 10 min. at 20 ct. an hr 0.033 Wear and tear of machinery 0.027 Total per 100 ft $0.320 The cost of plow and grader work is the average of all the ditches filled in this manner. They varied in depth from 2.5 to 5 ft., with an average of 3.5 ft. Cost of Tile Drainage in California. The. following from En- gineering and Contracting, Oct. 13, 1909, is an abstract of Bul- letin 217 of the United States Department of Agriculture. The cost of 2,300 ft. of 6-in. tile drains on the Dore tract in Cali- fornia was as follows, the excavation being in dry ground to an average depth of 4.5 ft. Digging trenches and laying tile 92 days, afr $2.50 per day $230.00 9 days, at $3.00 per day 27.00 $257.00 Filling trenches Two men and team, 6% days at $6.00 per day 39.00 Man with shovel in vines, 1 day at $2.50 per day 2.50 Total 778 HANDBOOK OF EARTH EXCAVATION There were 2,300 ft. of 6-in. tile laid. All of this was in vine- yard where the dirt had to be thrown away from the vines. In filling the ditches a filling scraper was used, and the vines in- terfered with this work considerably. However, the cost of filling this 2,300 ft., $41.50, gives 1.8 ct. per foot. The cost of digging the trenches and laying the tile was 11.2 ct. per foot. The tile cost 13.3 ct. per foot. This gives a total of 26.3 ct. per foot for tile and all work connected with laying it and filling the trenches. To this must be added 2 ct. for cable inserted in all tile, and 3.7 ct. for wooden sand boxes, making a total of 32 ct. per ft. Sand boxes were spaced 300 ft. apart, contained 215 ft. B. M., and cost $11 each. Use of Derricks and Locomotive Cranes. These are used to a considerable extent on trench work. For small but deep exca- vations in crowded city streets a hand operated derrick is well fitted to the requirements. Such derricks must be of light weight and easily moved and set up. Where the trench is continuous and there is room for its operation, a small steam operated der- rick is frequently mounted on rollers and carried along with the excavation. Its track may be directly over the trench, on the trench timbering or it may be carried along one side of the trench, provision being made in the timbering for the additional load. A locomotive crane is of still greater value, owing to its speed and increased range of work. With a crane it is possible to carry excavated material for back fill back along the trench. Steam operated derricks and cranes are usually used on trench work to handle skips or bottom dump buckets that are filled by hand. In this connection it should be remembered that the orange- peel bucket will excavate soft material very rapidly and that it will work well even after the shoring is placed in the trench. The material under the braces can be shoveled to where the bucket can pick it up. Use of Dragline Excavators. These are not adapted to work in confined areas. A dragline bucket cannot be used to cut close to line nor can it be operated where immediate timbering is necessary. It is well adapted for the first rough work on fairly large trenches in the open, especially where these do not require shoring. The bulk of excavation on certain trenches for the cut and cover section of the Catskill Aqueduct was taken out by drag-lines. These were afterwards trimmed to line and grade by hand, the additional material being handled in bottom dump buckets by a locomotive crane. Another machine which has been used with success in trenches METHODS AND COST OF TRENCHING 779 is a traveling swinging derrick, operating an orange-peel bucket. This machine moves on solid ground ahead of the trench. Victor Windett, in Engineering and Contracting) June 5, 1911, gives the output with this machine on several jobs in Indiana. With a %-yd. bucket, operated by a power swinging 56 ft. boom, the best day's work done was 920 cu. yd. excavated in 10 hr. This was in a trench sheeted by pile driving ahead of the digging. The braces were placed 8 ft. centers, as the depth of the digging required, in a trench 14 ft. wide by 12 ft. deep. The spoil in part was loaded on 3-yd. cars and in part dumped on the ground 50 ft. away. The soil was alluvial river deposit. In excavating for the Plaquemine, La., lock approach there was used a 3-cu. yd. orange-peel bucket hung from a boom 85 ft. long and loading on flat cars on a trestle 20 ft. above the working level. This boom was swung by gravity. The earth was wet Mississippi river alluvium. This bucket was changed in favor of a 2-cu. yd. bucket because the larger bucket overloaded the machine. The 3-cu. yd. bucket would, at times, take loads of approximately 4i cu. yd. heaped up over the bull wheel, which strained the timber framework. The digger discharged its load onto flat cars on a trestle ad- jacent to the work. The average haul for a loaded train was approximately 400 ft. Two light engines would handle 3 cars. Unloading was done by a Lidgerwood plow working between stakes on the sides of the car. The 3-cu. yd. bucket would place a load on the cars in 55 sec. With delays due to all causes the average output of the machine was 1,320 cu. yd. in a day of 10 hr. The labor cost was $0.19 per cu. yd. of earth dug, in- cluding operating, maintenance, transportation of spoil and un- loading. The maintenance of the trestle was a considerable item. For trench work a %-cu. yd. orange-peel bucket is about as large as can be economically used, because a larger bucket re- quires too much room, and would also require the bracing to be spaced farther apart than 8 ft. centers; this would necessitate timbers too heavy to be handled easily by the trenching gang. Cost of Trenching with a Derrick at Big Rapids, Mich. En- gineering and Contracting, Sept. 8, 1909, gives the following: A trench 4 ft. wide, from 14 ft. to 17.25 ft. deep, and 1,000 ft. long, was excavated for a 15-in. pipe sewer. The material was gravel and boulders. As much as 3 cords of stone were removed from 400 ft. of trench, many boulders requiring a 3,000-lb. chain- fall to handle them. The gravel was treacherous and required two to three sections of sheeting with three or four rangers. The first 4 to G ft. of trench were excavated by means of a drag scraper, fitted with inside bars and bail to enable it to cut ver- 780 HANDBOOK OF EARTH EXCAVATION tical sides. A team and driver did all this digging and back- filling. The remainder of the trench was excavated by a No. 1 Parker derrick. This derrick reduced the cost from 78 to 59 ct. per lin. ft., and the crew from 27 men required for hand work to 16 men with the derrick. The buckets held % cu. yd., and 01 to 68 buckets per hr, were handled by 4 loaders, 1 dump man, 1 derrick man, and a horse and driver. It required no more than 7 min. to move the derrick ahead 16 to 32 ft. The daily cost of the work was as follows: 1 foreman $ 2.00 1 scraper team and driver 3.75 1 man holding scraper 1.50 1 man dumping scraper 1.50 2 men pulling sheeting and carrying it ahead at $1.50. 3.00 man setting top section of sheeting 1.50 man tending derrick 1.50 horse and driver on haul line 2.50 men filling 2 buckets at $1.50 6.00 man laying pipe 2.00 pipelayer's helper 1.50 Total per day $26.75 This gang completed from 46 to 54 ft. of sewer per day; this gives a labor cost of 58.2 ct. to 49.5 ct. per lin. ft. of sewer. Deep Trenching at Brooklyn, N. Y. A description of the methods pursued in constructing the Green Avenue relief sewer, Brooklyn, N. Y., is contained in Engineering Record, Sept. 1, 1900. This sewer was constructed of brick and was 78 in. in diameter. The invert was situated 35 to 40 ft. below street level. When the depth exceeded 35 ft. it was customary to tunnel. The soil was of loam with a preponderance of fine soil. A track of 15-ft. gage spanned the sewer and on this traveled a car carrying a derrick. This derrick was equipped with a 25-ft. boom, and the buckets of earth were conveyed by it to a dump car alongside the trench. The trench was dug in sections 25 ft. long, 11 ft. wide and 4 ft. deep. Then the sheeting was started. A 4x10 in. ranger was placed at the bottom, and the sheet piling of 2-in. planks, 16 ft. long, was started. Two men with wooden mauls diove down this sheeting as fast as 6 men with shovels lowered the trench. The trench was excavated in 4 ft. benches, two men setting the rangers and sheeting as the work proceeded. The braces were of 4xlO-in. timber, and after being cut exactly to length were set in place with one end a foot or two to one side of the proper position. The braces were later driven horizontally into place and wedged there. A cleat was nailed across the brace at each end before it was put in position in order to prevent the brace from falling down. (See Fig. 3.) Cleats were also nailed to the METHODS AND COST. OF TRENCHING 781 782 HANDBOOK OF EARTH EXCAVATION sheet piling after it was down to grade in order to hold up the rangers. The rangers were all 25 ft. long, and were set with their joints opposite. Braces were 8 ft. apart except at the ends of the rangers: here the braces were placed 2 ft. each side of a joint. Excavation and timbering were carried on in three places by three gangs of 12 men each, in addition to the man on each derrick, and 6 men on the dump and at backfilling. The whole force completed 25 to 30 lin. ft. of trench in 8 hr. The trench being 10.5 ft. wide at bottom, 13 ft. wide at top, and 35 to 40 ft. deep, the gangs of 36 shovelers and timbermen excavated 480 cu. yd. per day or about 15 cu. yd. per man per day. However, since one-third of the men were timbering, the shovelers actually loaded 20 cu. yd. per man per day. Including the backfillers and engineers, the total force was 45 men, and, putting the coal con- sumption as equal to 3 men, the equivalent of 48 men dug at the rate of 10 cu. yd. per man per day. This was excellent work. The trench was perfectly dry, the sand being moist enough to stand well on a face 5 ft. high. The sewer gang proper comprised 2 men laying flooring plank and adjusting centers, 4 to 6 brick layers, 2 hod-carriers, 2 mor- tar mixers, 2 men lowering mortar and 2 men lowering brick. These 14 men laid 26 ft. of sewer (20,800 brick) in 8 hr. Use of a Derrick and Cars. Engineering and Contracting, Feb. 28, 1912, gives the following: A trench carrying a discharge pipe for an addition to the power plant of the Indiana Michigan Power Electric Co., South Bend, Ind., was excavated 30 ft. deep and 8 ft. wide at the top with a derrick. The materials encountered consisted of sand and gravel to a depth of about 10 ft., and clay to about 5 ft. in depth. With blue clay, containing occasional pockets of quick- sand beneath, sheeting plank, 2 in. thick and 12 ft. long were used. The earth and clay were excavated by hand, and thrown into car bodies of %-cu. yd. capacity, V-shaped and fitted with legs, so that they would stand upright on the ground or could be used 'on the cars. These car bodies were hoisted by a der- rick and placed on car trucks and run back for backfilling the trench. The derrick was equipped with a stiff leg arrangement which " would set on a portable frame straddling the trench, and was supported on a track, upon which it could be run back and forth over the work. The portable frame was built high enough to allow the cars to pass under it, the track for these cars was laid on stringers supported by the trench frame. Only one car truck was used, but 3 or 4 car bodies were kept in operation. METHODS AND COST OF TRENCHING 783 At the bottom of the trench a 42-in. concrete pipe was laid, and the earth was tamped in around it, nearly up to the center point. This was further backfilled to a depth of about 5 ft., at which depth the 36-in. pipe was laid and backfilled in the same man- ner. About 25 ft. of pipe trench were excavated and filled in a 10-hr, day, with a gang of 30 men. Derrick and Orange-Peel on Louisville Sewer Work. Engi- neering and Contracting, Jan. 29, 1910, gives the following: Fig. 4 shows a derrick owned by the American Engineering & Construction Co. of Chicago, used on one of their sewer contracts at Louisville, Ky. The work was the construction of a large concrete sewer 14 ft. in diameter and 4,230 ft. in length. The depth of sewer averaged 39.3 ft., and the average number of cubic yards of excavation per lineal foot was 26.5. In the beginning of the work a steam shovel was used for the first cut, but was abandoned as it was soon seen that the derrick could do the work required. The derrick took out the excavation to within 14 ft. of the bottom, and the balance was taken out with a Pot- ter machine and carried back for backfill. The derrick was equipped with an orange-peel bucket. The spoil material was deposited in wagons and was hauled away under a sub-contract at 11 ct. per cu, yd. The rest of the material excavated by the derrick was dumped into Koppel cars, located alongside the trench and hauled directly to the backfill. The derrick is a stiff leg, mounted on a portable turntable. The power plant consisting of a 30-hp. boiler and a 7 x 10-in. engine operating three drums, is mounted on the turntable in such a position as to balance the weight of the derrick and boom. The drums are equipped with two sets of gears permitting ar- rangement for a dragline bucket, if desired. The entire outfit cost about $6,500. The output of the derrick was about 63,000 cu. yd. and averaged 1,500 cu. yd. per week. The maximum out- put in one day was about 850 cu. yd. or 1,200 swings with the %-cu. yd. orange-peel bucket working in sand. The derrick was formerly known as a Kearns derrick and the patents on the swinging arrangement are held by the Lidger- wood Manufacturing Co. Trenching with a Grab Bucket in Wet Ground. Engineering and Contracting, Sept. 28, 1910, gives the following: In trenching through sand for a sewer at Gary, Ind., a V-shaped trench with sides at the natural slope of the material is found more economic than a narrow sheeted trench. The depth of cut ranges from 3 ft. to 22^ ft. and averages 14^ ft., and from 2 to 3 ft. of the bottom is below ground water level, so that the conditions are such as would ordinarily be considered as 784 HANDBOOK OF EARTH EXCAVATION METHODS AND COST OF TRENCHING 785 calling for a sheeted trench. At Gary there were no restrictions on the allowable width of trench, as the work was through open country, and the decision as to methods rested entirely on ques- tions of comparative cost. The contractor decided upon a method of bleeding the ground of the water by means of well points and opening a V-shaped cut of such width as might be necessary to get the depths required, using a grab bucket excavator. The result has been that the amount of excavation has been twice the volume required for a sheeted trench, but this 100% extra of digging has cost less than timber and sheeting labor would have cost. Briefly, the method of work is to make a cut with a grab bucket operated from a derrick running ahead of the cut, letting the sides of the cut curve to slope. The grab bucket makes the cut roughly to grade. The next operation is to sink a row of well points on each side of the trench bottom and connect them with a pump; the ground water is drawn out low enough to per- mit the trench bottom to be trimmed and the sewer concrete to be placed. The derrick is a rig built by the contractor of old timbers, and of such machinery as was at hand. The engine is 7 x 10-in., with vertical boiler. A swinging engine is also used. The ma- chine rests upon a turntable, which in turn travels forward on rollers. When desired to move, a line is led out to a tree or stump and fastened ; the other end is turned over a nigger-head on the engine and the machine pulled ahead as desired. The swinging of the boom is rapid and is accomplished by a cable which runs around the circular rail upon which the machine turns. The cable passes around this rail in the same manner as on the bull wheel of a derrick. An engineer and fireman operate the derrick. Two laborers prepare the ways for the rollers, and do the other necessary work around it, such as carrying coal and supplies. The Andersen-Evans (Chicago) grab bucket is of a new type, differing from the ordinary clam shell buckets in that the dif- ferential drum is not fastened to an extension of the scoop but is carried by a separate frame. The scoops swing from hinges on this frame and when opened up an unusually wide opening is secured. The separation of the pivots gives an excellent cut- ting motion and it is especially noticeable that a full bucket of materi.il is always secured when digging under water. This is unusual in such compacted material as sand under water. After the trench has been excavated to grade by the grab and the material deposited on both sides, the pump men begin the installation of the well points. Two 3-in. pipes about 100 786 HANDBOOK OF EARTH EXCAVATION ft. long are laid along the trench, one on each side of the im- mediate area to be unwatered. A valve with two nipples is located at 4 ft. intervals all along these mains and rubber hose connections are made between the mains and the points. The points consist of l^-in- galvanized pipes, which are jetted into the sand at 2 -ft. intervals. They have a metal point at the lower end and above the lower end for 2 ft. they are perforated with }&-in. holes and screened with fine wire mesh. It requires the time of 4 to 6 men to set these points ahead of the concrete work and to pull them after the invert has been put in. A small steam pump is attached to the 3-in. mains and the elevation of the ground water is lowered below the bottom of the sewer and the ground is trimmed to the circular shape fitting the invert. The progress on the work for 10 days is an indication of the success with which it' is being carried on. The average number of lineal feet of completed sewer (not back filled) was 1)3 ft. per day. The smallest day's work was 69 lin. ft. and the greatest was 124 lin. ft. Trenching with a Dragline Excavator. The use of a drag- line bucket for excavating a trench for a water main at Bal- timore, Md., is described by J. C. Lathrop, in Engineering News, Nov. 19, 1914. The work on which this machine- was used was a trench about 1,700 ft. long, the average depth being 15 ft., varying from 12 ft. at one end to 20 ft. at the other, and the width 18 ft. A dragline bucket with a capacity of 22 cii. ft. pulled up an incline by a hoisting engine, dumped into a bin and delivered to carts or wagons. The total amount of earth removed by this method was about 13,000 cu. yd., one-fourth of which was hauled away to allow for the space occupied by the pipe in the trench. The balance was piled up at one side of the trench to form an embankment upon which was placed track for a locomotive and for the locomotive crane used to handle the concrete pipe sections. A drag-scraper bucket was used in place of a steam shovel be- cause of the character of the material, it being necessary to sheet the bank as the excavation proceeded. Rangers or waling strips, 6 by 8 in. by 16 ft., were held in place and cross-braced by other 6 by 8-in. timbers. The sheeting were driven by two small steam hammers carried by blocks and falls, hung from steel cables directly over each line of sheeting. Steam for the ham- mers was supplied by the hoist engine boiler and a traction engine. As high an output as 250 bucketfuls were removed in a working day at the average rate of a round trip in 2 min. Trenching with Steam Shovels. Steam shovels have been used METHODS AND COST OF TRENCHING 787 for some years for trench excavation, and each year shows more efficient work done by them. When shovels were built of the old crane type they did not have as great an angle of swing as the present trench digging shovels have, with the result that the dirt was piled up so close to the trench as to interfere not only with the work of excavation but also with the other work that had to be done in the trench. The modern boom shovel was an improvement over the crane type, but the great improvement came in steam shovels for trench work when the full circle re- volving shovel was introduced. When- the trench is of such dimensions that a small shovel can be used, revolving or full-swing shovels will prove much more advantageous than standard machines. Some of the prin- cipal advantages of the revolving type of shovel over the ordi- nary type are as follows: First, the revolving shovel can start a cut, moving gradually along until the required depth is reached, then turn around and excavate the " heel " that is left, whereas the cut for the standard shovel must be started by hand. Second, in the standard type of machine the steering wheels are in the rear, and some skill is required to steer the machine and keep it exactly over the trench, whereas with the revolving shovel the steering wheels can be placed at the front end. Third, where conditions are favorable, the excavation and backfill can be made at the same time. Fourth, with this type of shovel the excavated material can be kept well away from the trench and a large amount of material piled up on the bank. As the pile be- comes high, the dipper of the shovel is used as a ram, pushing off the top of the pile of earth, and away from the trench. Naturally, when the soil is sandy or in a material that has a tendency to cave, close sheeting and heavy bracing are required to enable the banks to carry the weight directly above them. When it is necessary to sheet directly beneath a shovel, digging must cease. This makes the percentage of idle time high, and the cost excessive in any but firm, hard ground. In ordinary soils a trench excavator will generally prove a more economical machine. On the other hand, in hard clay and boulders the steam shovel is a most effective tool. As a steam shovel works into, instead of away from, the ma- terial it is excavating, it must be carried by the banks of the trench already excavated. The machine straddles the trench, being carried on heavy timbers lying transversely beneath it. With wide trenches, heavier, firmer timbers, or timber and steel platforms, must be used, and the shovel removed from its trucks and placed on rollers or on caterpillar wheels. For trench excavation the regular length dipper arm is taken 788 HANDBOOK OF EARTH EXCAVATION off the shovel and a much longer dipper arm substituted. Trenches are dug with these long dipper arms from 14 to 18 ft. deep, while in a few cases they have been taken to a depth of from 20 to 22 ft. Shovels meant for trench work vary in weight from 25 to 45 tons. Heavier shovels than these are apt to cave in the sides of the trench, and are difficult to move. Even a 45-ton shovel is often too heavy for this class of excavation. Such weight shovels are usually mounted on traction wheels, although they can be mounted on railroad trucks. However, for trench work heavy shovels are generally taken off their trucks and mounted on sills. Truss rods are not used unless the trench is wide. Timbers, or timbers that are trussed to give them additional strength, 12x12 in., are generally used for this purpose. Some ^con- tractors have made it a practice to build a platform across the trench and to place the shovel, mounted on its traction wheels, on this platform. This practice is wrong when the trench is very deep and of considerable length. The shovel is raised a foot or so higher than it would be were the wheels removed. However, when the shovel must often be moved from one stretch of sewer to another, it should be left on its wheels and sectional plat- forms used for supporting it above the trench. In Fig. 5 the usual method of mounting a shovel for narrow trench work is shown. Heavy planks should always be laid down for the rollers to run on. It is generally well to have the rollers long enough to admit of two holes being , bored through the ends so that bars can be used to straighten up the rollers when necessary, and also to move the machine by means of bars. However, the machine is not moved in that manner except when steam is not up. In Fig. 5, a small drum is shown beneath the machine. From this drum a hauling line Js run to a dead man placed several hundred feet ahead of the machine, and the shovel is moved by its own steam by winding up this line on the drum. The shovel roughly shapes the bottom of the trench, and the work is completed by a small gang of men working under the body of the machine. They cast the earth ahead so as to enable the shovel to remove it. The shovel is mounted very low for deep digging. It is pos- sible to carry the truss rods below the natural surface of the ground in trench digging, as they will not interfere with the work if they are properly placed on the timbers. When the shovel is to be moved over the ground from one trench to an- other, the whole frame can be jacked up and timbers placed over the rollers, thus raising the frame to such a height, so that the truss rods will not interfere with the ground as the shovel is METHODS AND COST OF TKENCHING 789 I 790 HANDBOOK OF EARTH EXCAVATION moved. There is no reason, however, why heavy 12-in. steel I beams should not be used in place of the timber, thus doing away with the truss rods, and channel irons could be used on each side in place of the longitudinal timbers, thus allowing the shovel to be mounted lower. Shovels of the revolving type are best for the excavation of narrow trenches. Instead of mounting the shovels on a skele- ton frame, a platform can be built to hold the turntable, thus adding to the height. However, with steel beams, this height could be reduced. A good motto to follow is to keep the shovel low. No matter how the machine is mounted, arrangements should be made to hold the shovel in its position while digging, for in hard excavation, unless this is done the shovel will back away from the breast and much time is lost. Additional Points in Using a Steam Shovel. Engineering and Contracting, July 19, 1916, gives the following: In digging large trenches, the following hints may be useful. First. Change the position of the levers that operate the shovel, placing them about 5 ft. outside the shovel-house, on an extension platform built for the purpose. Standing there the operator can see the bottom of the trench even where it is 25 ft. or more deep. Second. Remove the traction wheels and mount the shovel on rollers that rest on timbers laid on opposite sides of the trench. The shovel is shifted by means of a cable anchored to a deadman, and operated by the main engines. A 60-ton or 70- ton shovel can be moved on rollers 120 ft. per hour over level ground. Third. Ordinarily it is best to excavate a deep trench (18 ft. or more deep) in two "lifts" or benches. Work one day on the upper bench, then back up and work the next day on the lower lift. In the upper "bench" use two 50-ft. I beams as "rangers" to support the " sheeting " of vertical planks. One I beam is placed horizontally on each side of the trench, about half way up the " lift," and jackscrew braces every 20 ft. hold the I beams and sheeting in place. Regular . timber rangers and braces are also used, but some of these must be temporarily removed when the shovel is digging out the lower bench or lift, and then it is that the I beams hold the sheeting in place. When the shovel is shifted forward (15 ft. or so), the I beams are fastened to the shovel and moved forward with it, after loosening the jackscrews that hold the I beams apart. It takes about half an hour to shift a large shovel forward 15 ft. on rollers. METHODS AND COST OF TRENCHING 791 Sheeting and Bracing Under Steam Shovels. Engineering and Contracting, June 14, 1911, gives the following: Sheet planking should be cut to the proper length as they can- not be driven but must be placed after the trench has been dug the full depth. When the shovel is carried on a permanent plat- form this serves as a convenient carrying place for the shoring also. If the banks will stand up without shoring it is cheaper to do that afterward. However, the pressure on the banks caused by a shovel is great, and no chances should be taken. In very treacherous ground the shoring should always be kept up close to the point of digging, but it is permissible to brace the trench temporarily and to put in the permanent shoring after the shovel has passed. Bracing must be accomplished very rapidly or the shovel will be materially delayed. As soon as the dipper enters the trench for its last stroke the operator blows the whistle arid the sheet- ing men prepare to act. When the upward stroke of the shovel is half completed these men quickly plaee the stringers and braces. The work calls for great speed as a cave-in may occur in a few seconds. In some cases the trench is braced, in the portion being exca- vated, by two stiff steel beams with a cross brace at each end. The rear end of these beams is carried by chains hung from the frame of the shovel, and the forward end rests on the ground. These beams are used at a depth of 2 ft. or so below the ground surface. In moving these beams ahead the forward chain at- tached to them is caught over the dipper and pulled ahead by a forward stroke of the dipper, as in Fig. 6. Sometimes, especially when the soil is soft and alluvial or in sand, the sheeting can be driven along the line of the proposed trench, and the material afterwards excavated with a steam shovel. The cost of steam shovel operations under such con- ditions was a-s follows: In New Orleans, using a half-yard dipper 25-ton steam shovel over a trench 14 ft. wide and 12 ft. deep, 855 lin. ft. of trench, or 5,320 cu. yd. of earth, were dug in 55 hr. of work. The soil was alluvial river mud in an old partly drained cypress swamp, consisting of 1/4 cypress roots and stumps. The sheet- ing for the trench sides had been driven ahead of the shovel and the bracing was carried on simultaneously with the digging of the trench. As the sheeting and bracing were a part of the permanent construction of the canal, a temporary set of stringers and braces was used for the operation of the shovel. The labor- cost of this trenching, including the bracing, was 8 ct. per cu. 702 HANDBOOK OF EARTH EXCAVATION yd. To this expense should be added the expense of moving the shovel on and olf the job, which amounted to 4 ct. additional, making the total cost 12 ct. per cu. yd. Fig. 6. Moving Steel Walings Used in Steam Shovel Trench Work. In work in sand on Long Island steel sheet piling for small trenches excavated by a steam shovel was proposed. For this purpose the following tools and material were purchased. 600 pieces of No. 12 Wemlinger sheeting, each 10 ft. long, at 28 ct. per sq. ft $1,680.00 800 lin. ft. of 3 x 8-in. timber at $28 per M 44.80 100 extension braces at $1.00 100.00 200 ft. of marlin wound steam hose at 46 ct. per ft... 92.00 1 steam pile hammer 200.00 1 driving .cap 10.00 Total cost of pile driving outfit $2,126.80 The intention was to have the steam shovel furnish the steam required for power. Sheeting would then be driven in place ahead of the shovel by a pile hammer. This plan of work was METHODS AND COST OF TRENCHING 793 never carried out, because it was feared that with narrow trenches widths on curves, and with a caving soil, a steam shovel would prove an uneconomic tool. However, given wider trenches and better soil this method of driving piles might prove eco- nomical. Method of Supporting- Small Shovels. The following is from the Excavating Engineer, Juno, 1914, and Jan., 1915: An 18-ton Bucyrus revolving steam shovel digging trenches at Washington, D. C., is illustrated in Fig. 7. This machine was equipped with a 27-ft. dipper handle, enabling it to dig to a depth of 18 ft. The dipper had a capacity of % cu. yd. It was fitted with five forged teeth, three on the front and one on each side. The machine was carried on seven 12xl2-in. timbers spanning the trench. These timbers were fitted with U-bolts and were moved forward by means of a chain-sling hung from the dipper. On the traction wheels of the shovel a double flange of riveted channel irons enabled the machine to travel on sections of rail. These sections were 3 ft. long. An 18-ton, %-cu. yd. dipper Bucyrus revolving shovel was used for excavating trench for a 36-in. water pipe at Cincinnati, 0., during the fall of 1914. The shovel was carried on cross beams, joined in sets of two, resting on longitudinal stringers laid beside the trench. The traction wheels rested directly on planks laid on the cross beams. The trench was excavated 5 ft. wide and 7 ft. deep. The material was yellow clay and stony subsoil. The rate of digging averaged 300 lin. ft., or 390 cu. yd. per day, with a maximum of 375 lin. ft. in 10 hr. Although the dipper was not furnished with teeth, no difficulty was experienced in excavating this kind of material. The pipe was usually handled by two traveling derricks, but where these could not be readily used, the pipe was handled by the shovel. Each section of pipe weighed 6,500 Ib. Cost with a Revolving Shovel at Auburn, N. Y. The method pursued in excavating 13 miles of pipe sewer trench at Auburn during 1919 is described in Engineering and Contracting, Mar. 2, 1910. The sewers varied in diameter between 5 and 24 in. Trenches were ordinarily dug 1 ft. wider than the diameter of the sewer. The average depth was 9 ft., and the greatest depth was 19 ft. The material excavated was clay and glacial drift, with embedded boulders. Pockets of quicksand were encountered at places. The upper 3 to 5 ft. were good digging, the remainder being difficult. The quicksand pockets and stonier parts that required blasting were excavated by hand. Sheeting of 2-in. cull oak planks, set vertically, and braced 704 HANDBOOK OF EARTH EXCAVATION METHODS AND COST OF TRENCHING ?95 with extension braces, were used in the quicksand and in wet places. About 3,000 lin. ft. of trench required sheeting. The shovel used for excavating the major portion of the trenches was a No. 1 revolving Vulcan Steam shovel, weighing 35 tons, mounted on traction wheels, and equipped with a %-cu. yd. dip- per and a 27-ft. dipper handle. This machine could dig to depths of 16 ft. The timber platform used to support the machine was in three sections of a design similar to that previously described. Each move forward of the shovel occupied 4 to 5 minutes. Pipe was laid directly beneath the shovel, and the material was used for backfilling as fast as it was excavated, the shovel making a swing through an arc of 180 and dumping the earth directly at the rear. When rock, boulders or other obstructions prevented the completion of the trench to grade, the excavated earth was piled alongside the trench and the shovel was not held up. The crew required numbered 20. Assuming the rates of wages then current, the daily coal and labor cost was as follows: 1 engineman $ 5.00 1 fireman 3.00 3 laborers placing track, etc., at $1.50 4.50 4 men placing sheeting 6.00 2 men placing extension braces 3.00 1 man carrying planks 1.50 2 pipe layers at $2.00 4.00 2 pipe handlers at $1.50 3.00 2 mortar mixers 3.00 1 instrument man 3.00 1,200 Ib. of coal 3.00 Total $39.00 From 90 to 125 lin. ft. of 4-ft. x 7-ft. deep trench, or 50 to 75 lin. ft. of 4 x 12-ft. trench were excavated per 8-hr. day. This gives a daily yardage of 90 to 135 cu. yd.- excavated. Steam Shovel Work in Milwaukee. In Engineering and Con- tracting, Feb. 26, 1908, Geo. E. Zimmerman gives the following. Mr. Zimmerman began using a Vulcan shovel for sewer work in 1903. He stated that a shovel paid best on trenches 4 to 10 ft. wide, and that he preferred a trench excavator for pipe sewer and water main work. The shovel was mounted on traction wheels, and was carried above the trench on a timber platform. This platform was con- structed of 6 x 8-in. x 16-ft. timbers laid across the trench with two " rails " of two heavy plank laid side by side with broken joints to form a track. In order not to delay the progress of the shovel, about 40 cross-timbers were required. This method of supporting the shovel is not as economical as the platform 796 HANDBOOK OF EARTH EXCAVATION used for similar work previously described. With separate cross- timbers it was necessary for the pitmen to carry about 8 timbers forward for each 8-ft. move. The working force consisted of the following men: 1 engineman $ 5.00 1 craneman 3.50 4 laborers at $3 12.00 Coal 3.00 Total $23.50 About one-half of the time was spent in shoring the trench and moving the shovel ahead. The cost of digging depended on the nature of the ground. An 8 x 14-ft. trench, 2,200 ft. long, cost 38 ct. per lin. ft., or at the rate of 9.3 ct. per cu. yd. Mr. Zim- mermann estimated that the same trench if dug by hand would have cost 61 ct. per cu. yd. Steam Shovel Work at Wilmette, 111. The Excavating Engi- neer, Oct., 1914, gives the following: The trench for a concrete, elliptical, 6 x 9-ft. sewer near Chi- cago was dug by a Bucyrus 60-ton steam shovel. This machine was equipped with a 1.5-yd. special trench dipper, a 50-ft. dipper handle, and a 36-ft. boom. The shovel was mounted on heavy trusses spanning the trench and traveled on skids and rollers. The operating levers were carried on a special platform at the right hand side of the deck, thus enabling the operator to get a clear view of the trench being dug. The material was loaded into twenty-four 4-yd. dump cars, drawn in three trains by three 18- ton locomotives. The shovel was drawn ahead in 16-ft. moves by a cable attached to a deadman. At the end of each move the ma- chine stopped long enough to enable the sheeting gang to sheet and brace the trench. The trench was dug to within 6 in. of the specified width and within a few inches of grade. Two men shaped the bottom of the trench with mattocks. The sheeting was of vertical planks, with horizontal rangers held apart by wood braces fitted with pack screws. These braces were spaced 5 ft. apart. The material was hauled back to the completed section of the sewer and used for backfill, the earth being dumped directly from the cars into the trench alongside. Except for a soil topping the material was stiff blue clay, mak- ing very heavy digging. The trench was in general 22 ft. deep and 8 ft. wide. The rate of advance of the shovel was limited, however, by the speed of the concrete gangs behind. The average rate of digging was 5 to 6 moves, or 78 to 96 ft., or 585 to 729 cu. yd. per 9 hr. Steam Shovel Trenching at the Chicago Clearing Yards. The METHODS AND COST OF TRENCHING 797 following data are from Engineering Record, August 2, 1902, and Engineering News, November 7, 1901. N The territory, about 4,000 acres occupied by the Chicago Trans- fer and Clearing Co., was drained into the Illinois and Michigan Canal by concrete sewers. The width of the necessary trench was 14 ft. at the ground surface for 90-in. sewers, and 7 ft. for 36-in. sewers. A 75-ton Vulcan steam shovel, with a 1.5-yd. dipper and a 36-ft. dipper arm, was used for excavating the larger trenches. A Bucyrus shovel with a %-yd. dipper was used for the smaller trenches. The sheeting and bracing were put in as the work pro- gressed, the sheeting being composed of planks set vertically, and the bracing of extensible iron tubing. On some days the Vulcan output was double the average output given below. The deeper trenches were excavated by the shovels to a depth of 20 ft., leav- ing 2 to 4 ft. to be taken out by hand. Hand excavated material was loaded into buckets, raised by a swing-boom derrick, mounted directly over the trench. About 12 men in groups of 4 men each, loaded these 2-yd. buckets. A gang of 12 men, working in hard blue clay and carefully trimming for the invert, easily ex- cavated the 4-ft. bottom layer of the 90-in. sewer for a length of 100 ft., in 10 hr. Very little picking was done. Round pointed, short handled shovels with foot-irons were most effective. The backfilling was done entirely by a swing-boom derrick, straddling the trench and mounted on rollers, which operated a scraper. This scraper was made of the bowl of a wheel-scraper fitted with a bail and handles. The cable was endless, passing around the drum of a double-cylinder engine and through a sheave at the end of the boom, and served to draw the scraper backward and forward. Two men held the scraper while it was being filled. The machine with an engineman, fireman, and 2 loaders, back- filled 900 cu. yd. per day. No tamping was required. In trenches 12.5 ft. wide and 17 to 20 ft. deep the Vulcan shovel averaged 570 cu. yd. per 10-hr, day. In trenches 6.5 ft. wide and 11 to 14 ft. deep the Bucyrus shovel averaged 305 cu. yd. per day. Steam Shovel Work on Chicago Sewers. In Engineering and Contracting, Feb. 11. 1914, H. R. Abbott gives the methods and costs of constructing large brick and concrete sewers in West 39th St., Chicago. The total length of the West 39th St. conduit was 2,346 ft., of which 1,868 ft. was plain concrete and 478 ft. was reinforced concrete. The conduit was elliptical in section and 12x14 ft. in interior size. The concrete was from 12 to 20 in. thick. Excavation was started at the \Vestern Ave. end in open cut. A Bucyrus 70-ton steam shovel was used with 1%-cu. yd. dipper. The shovel was mounted on five 16 x 18-in. timbers, 30 ft. long, 708 HANDBOOK OF EARTH EXCAVATION with two 2-in. truss rods to each timber. The top 4 ft. of trench was excavated about 3 ft. wider than the outside lines of the masonry, since no bracing, was put in near the top of the trench. Below this the trench excavation was made to the exact width of the masonry, plus an allowance of 4 in. for sheeting. Although a variation in and out was unavoidable, it did not exceed 2 in. in either direction. The trench width was 15 ft. 8 in.; average cut was 23 ft. 6 in., making an excavation of 13.7 cu. yd. per running foot. On account of the deep cut, the shovel was equipped with a 36-ft. boom and a 54-ft. dipper handle. As there was liability of slides and cave-ins, the excavation was handled in two lifts. On the first run the shovel excavated the top 10 ft., using 9-ft. sheeting with one set of bracing placed about 6 ft. below the ground surface. The shovel dug ahead of the finished cut from 75 to 100 ft., then backed up and excavated the lower 131/6 ft. The lower lift was taken out between steel beams, each built up of two 10-in. I-beams with cover plates, 50 ft. long, held in place by screw braces set 7 ft. back from each end. This re- places the ordinary wooden bracing and allows a free movement of the dipper in the trench for three moves or 36 ft. When a sec- tion is finished, the beams are carried ahead by the dipper, the wooden braces are replaced on the top sheeting, and another set of 9-ft. sheeting is placed with two sets of braces for the lower portion of the trench, the lower end of the sheeting being at a point where the invert curve meets the side wall. The lower sheeting back of the concrete was left in permanently. The bottom was trimmed and shaped by four or five bottom men, the material being cast ahead -where the shovel could reach it. An iron frame or template built to the dimensions of the outside lines of the masonry was set up every 12 ft. as a guide in trim- ming the sides. The excavated material was loaded direct from the shovel on to 4-cu. yd. dump cars operating on a 3-ft. gage track. Ordinarily, the upper lift made the backfill, and the lower lift was run to a spoil area in McKinley Park, a haul of about % mile. The sheeting was 2 x 10-in. hemlock, the braces 8x8 in. and 6x6 in., with stringers 6x8 in. of yellow pine. Concrete was mixed in a mixer mounted on timbers spanning the trench and delivering through spouts. The section contained about 2.5 cu. yd. per lin. ft. and a daily average of 75 cu. yd. was placed. The average progress per day of 9 hr. was 30 lin. ft. for both shovel and mixer for the plain concrete section. This meant 420 cu. yd. of excavation, with disposal in backfill or spoil bank. On the mixer platform was mounted a small boom derrick and METHODS AND COST OF TRENCHING 799 hoisting engine. This facilitated the removal of stringers and braces and pulled the mixer platform back and forth. Backfill was made by 4-yd. dump cars, the track being shifted over the conduit as the filling progressed. The centers were left in until the sides were thoroughly compacted and at least 1 ft. of filling had been placed over the arch. The foice employed was as follows: 1 superintendent $8.00 1 shovel engineman 7.00 3 dinkey enginemen 3.60 1 craneman 4.50 1 fireman 3.00 3 switchmen 2.25 2 flagmen 1.75 1 coal passer 2.50 3 foremen 4.50 1 hoisting engineman 5.60 4 bottom men 3.85 50 to 60 laborers 2.50 1 team 5.00 1 carpenter 4.80 1 machinist 3.50 1 machinist helper 2.50 1 office boy 2.00 1 material man 2.50 1 watchman 2.50 3 Waterboys 1.00 The cost of trenching on two sections was as follows per cu. yd. of trench : A B Labor excavating $0.188 $0.194 Plant excavating 0.046 0.046 Backfill 0.143 0.249 Disposal of waste 0.120 0.011 sposa il .. Coal 0.090 Total $0.587 $0.620 In building 10,000 ft. of brick sewer (7 to 7.5 ft. diam.) on South 52d Ave., the average progress per day on the 7-ft. section was 45 ft., equivalent to 330 cu. yd. of excavation, while on the 7 1 /-ft. section the average progress was 70 ft. per day, with 20 ft. cut or 500 cu. yd. of excavation per day. The difference in the progress between these two sections was partly due to the fact that the 7^-ft. sewer was built in a" street 80 ft. wide, with open prairie on one side and unlimited room for work, and the 7-ft. section was built in a 66-ft. street with scant open space adjacent to the street. Backfilling was done with a Monaghan revolving derrick, equipped with a Page orange-peel bucket, capacity 1 cu. yd. This is a very efficient machine for backfilling, but the operator should avoid dropping the load from any distance, as it is apt to 800 HANDBOOK OF EARTH EXCAVATION crack the masonry, especially when working during wet weather, when the backfilling is saturated with water. Some special items may be worthy of mention, such as the cost of hand excavation in a sewer trench of this size, moving plant, etc. In one case the steam shovel could not take out the bottom on account of the proximity of a viaduct. This earth was scaf- folded out at a cost of $1.06 per cu. yd., being handled four times before it reached the spoil bank. The cost of moving of the steam shovel a distance of 1,050 ft. across a railroad yard and over the tunnel section was $560, or 53 ct. per ft. This includes the partial dismantling of the shovel to pass under obstructions. At the start the shovel was taken off the railroad spur, moved % mile and placed on timbers to span the trench, at a cost of $750. A Steam Shovel and Conveyor Plant. Engineering Xews, Oct. 11, 1894, gives the follpwing: Fig. 8. Sketch Detail of Conveyor Floor and Scrapers. In the construction of very large deep sewers a large part of the excavated material must be wasted and the remainder used METHODS AND COST OF TRENCHING 801 for backfill. For this reason it will often prove economical to dig sewer trenches of this type in two lifts or benches loading the material excavated from the upper lift onto cars for dis- posal in suitable places at a greater or less distance, and shift- ing the material as fast as excavated from the second lift to the completed part of the sewer for use in backfilling. These methods were pursued in the construction of the Wentworth Ave. trunk sewer, Chicago. The Wentworth Ave. sewer is of brick with diameters of 5, 7 and 10.5 ft. for 6.5 miles, and diameters of 2.5 to 5.5 ft. for 3.75 miles. On the main portions the cuts were often very deep, ranging from 20 to 47 ft. in depth for a distance of 3 miles. The ground was very treacherous in places and for that reason and because of the great depth, special methods of excavation were required. The excavation and backfill were performed almost entirely by machinery. One steam shovel excavated the top soil to depths as great as 25 or 30 ft., loading the material onto flat cars on track directly alongside the trench. This track connected with the lines of the Illinois Central R. R., and the excavated material was removed to a distance and not used for backfill. After the first cut had been completed piles were driven on 3-ft. centers, in two rows at the side of the trench and about 16.5 ft. apart. Timber lagging was fastened to the piles on the outer sides. When the removal of these piles did not bring too great a pressure upon the green masonry they were withdrawn upon the completion of the brickwork. A second steam shovel on rollers travelled on 12 x 12-in. tim- ber caps on the piles. This machine excavated between the rows of piles. The material in the deep cuts was soft, sticky blue clay. As the excavation deepened the side pressure tended to force the piles inward and the extensible iron braces often buckled. The material excavated in the lower lift was dumped directly upon a scraper conveyor operating along a track, parallel to the sewer. This conveyor carried the material to the rear of the brick work, and dumped on to a cross conveyor or apron which led the ma- terial to the top of the completed sewer. Thus only one handling of the material was required. The conveyor consisted of a stationary floor mounted on wheels and tracks, over which a series of scrapers passed. The scrapers were carried between two endless chains that passed over sprocket wheels at each end of the floor. These chains were operated from a power car at the head of the conveyor. The conveyor worked satisfactorily^ The speed of the masons 802 HANDBOOK OF EARTH EXCAVATION METHODS AND COST OF TRENCHING 803 determined the rate of progress of the work and the machinery was often idle. A Special Backfilling Wagon. The Excavating Engineer, Oct., 1915, gives the following: Fig. 9 illustrates a 19-ton, %-yd. dipper Bucyrus steam shovel, loading a backfilling wagon on trench work 'in Chicago. This shovel was mounted on traction-wheels and carried on wooden platforms spanning the trench. These platforms, six in all, were 24 ft. long by 30 in. wide. Fig. 10 illustrates their construction. They were made of two 12 x 12-in. timbers, 24 ft. long, armored on the inner faces by ^-in. plates. They were separated by an- other 12-in. timber, 14 ft. long with the center cut away for the insertion of steel straps, on which was hung a ring for handling. \Ring-fortfandlinq i i J~*!'*il t i* ! i_i If iiftl' J^'i-'fi < ffikU' \_J^ fj jj 1 / i*f"ls sj" -^i-i*!!/ * n " ; *Lt*. Fig. 10. Platform Used by W. J. Newman for Mounting Revolv- ing Shovel for Sewer Work. The work was done in the construction of a 5.5-ft. circular brick sewer on Canal street. The trench was from 14 to 20 ft. in depth, and t) ft. wide. The material was tough blue clay with occasional boulders; a hard material to dig, but one which re- quired comparatively little sheeting. The progress was from 60 to 85 lin. ft. per 10-hr, day. The method of handling the backfill was unusually successful. Two wagons designed especially by W. J. Newjnan, consisting of an ordinary wagon truck on which was mounted a triangular box, the top of which was about 10 ft. above the ground, were used for this purpose. The floor of the box was a chute, start- ing at the top of the box and extending at an angle of about 45 a distance of about 3 ft. over the side of the wagon. This side of the wagon consisted of a hinged door controlled by a lever beside the driver's seat. Each wagon had a capacity of 3 cu. yd. The excavated material was loaded into this wagon and then carried to the point in the trench which was to be back- filled, where the door was opened and the material was chuted into place. Besides the shovel crew there were 4 men in the trench shap- ing for the forms and handling the sheeting. These men assisted 804 HANDBOOK OF EARTH EXCAVATION in handling the platforms when moving forward. Two men were employed tamping backfill. Rapid Work with Small Steam Shovel. According to Engi- neering and Contracting, Oct. 18, 1916, a Model 18 shovel, made by the Osgood Company of Marion, Ohio, made exceptional prog- ress. The shovel which was equipped with a 19-ft. dipper handle and %-cu. yd. dipper is stated to have excavated a sewer trench 46 in. wide, 15 ft. deep and 150 ft. long in a 9-hr. day. The ma- terial consisted of very dry and hard clay mixed with boulders. After the pipe was laid the shovel refilled the trench. On another job this machine, similarly equipped, excavated a sewer trench 17 ft. deep, 9 ft. wide and 76 ft. long in 7y 2 hr., loading one-half of the material into wagons and depositing the other half on one side of the trench. Steam Shovel Costs on Sewer Work in New York City. En- gineering and Contracting, Dec. 2, 1908, in a long article on sewer construction in the Bronx Borough, N. Y. City, gives costs of steam shovel work on the Whitlock Ave. Sewer. A No. 2 Giant re- volving trench shovel, made by the Vulcan Co., was used. It was operated by a crew of a shovel runner, cranesman, fireman and 4 ground men. A smaller crew than this could be used, but more efficient work is done with such a crew, and it is generally poor economy to attempt to save money by having a small crew in steam shovel work, except where the amount of excavation to be done daily is limited. This shovel worked in a hard clay with a good many boulders in it, the boulders generally being smaller than 14 cu - yd- A fair day's work in this material was about 300 cu. ,yd., working only 8 hours. The shovel on a number of occasions dug 250 cu. yd. in 4 hr., which is at the rate of 500 cu. yd. per 8-hr. day. The cost of running the shovel a day was as follows: Shovel runner, at $175 per month $ 6.65 Craneman, at $140 per month 5.40 Fireman, at $60 per month 2.30 4 laborers, at $2.25 per day 10.00 1,800 Ib. of coal, at $3.50 3.15 Oil and waste , 0.50 Interest, depreciation and repairs (estimated) 6.00 Total per day $34.00 The cost of the plant was about $5,000, and the estimated item of interest, depreciation and repairs based on 200 working days per year, with an annual allowance of 24%. With an output of 300 cu. yd. per day the cost per cu. yd. was as follows: Shovel runner .~~. $0.022 Craneman 0.018 Fireman 0.00 METHODS AND COST OF TRENCHING BOS Laborers $0.033 Coal 0.010 Oil and waste 0.002 Plant 0.020 Total per cu. yd $0.113 This machine was moved over the streets, a distance of about i a mile. The time consumed was three days, the cost of moving being : Shovel runner $ 19.95 Craneman 16.20 Fireman 6.90 4 laborers 30.00 6 extra men 36.00 2,700 Ib. of coal 5.22 Oil and waste 0.50 Total $114.77 This means a cost of about $230 per mile moved. In moving the shovel long distances, it can be taken off its truss work and mounted on heavy, wide tread traction wheels, whereby the cost of moving is materially reduced. Use of Steam Shovel on Curved Trenches. Richard T. Dana, in an analysis of trenching methods and costs,, given in Engineering Record? May 23, 1914, is authority for the following costs on steam shovel trenching: Trenches were dug for the purpose of laying sanitary and storm-water pipe of varying diameters from 4 to 36 in. of tile and concrete, and also for cast-iron water pipe from 4 to 12 in. in size. Nearly all of the work was on curves, since the ewer and pipe lines had to be between the curbs of the streets, and curved streets, while not economical to construct, were considered artistic and, therefore, desirable notwithstanding the extra cost. The shovel was of the 25-ton, revolving type, mounted on trac- tion wheels. The entire mechanism was under the control of the runner, and the shovel was fitted with a dipper a,rm and 1-yd. dip- per specially designed for trench work, with an interchangeable boom capable of handling a small orange-peel bucket for cellar or stock-pile work. The platform upon which the shovel worked consisted of 12 timbers of 12 x 12-in. section, spaced 4 in. apart, and bolted together in sections of three. These twelve timbers rested upon planks laid upon the ground. On top of the timbers and running, transversely to them, near each end, were planks upon which the traction wheels rested directly. To move up after a completed section had been sheeted, the shovel swung around and with a chain picked up one of the sections, and swung back again and placed it upon the planks which the laborers had laid ahead. Then after the plank track had been laid, the shovel moved forward under its own power. 800 HANDBOOK OF EARTH EXCAVATION In Table 1 the time given under " time worked by shovel " in- cludes all time of moving up and waiting for sheeters before moving up, as well as the actual digging time of shovel. It is that time which could rightly be charged to the shovel. But when the sheeting gave out and the shovel was idle, as fre- quently happened during the experiment, such time was not charged to the shovel. This suggests one very important point, namely, always to have sufficient supplies and material on hand to prevent high-priced machinery from being idle. At times considerable time was lost on account of caving banks. Curves caused a delay of 14% on one day and 50% on another. TABLE I WORK OF 25-TON REVOLVING SHOVEL ONE-DAY PERFORMANCE Kind of shovel 25-ton Capacity of dipper 1 yd. Length of move 4 ft. Number of moves 20 Average time to>sheet trench before moving up 9.2 min. Average time to move up 4.5 min. Time worked by shovel 565 min. Cut 9 ft. Width 36 in. Material, clay and gravel that held up well. Remarks: Shovel idle while trench was being sheeted. Curve also caused idleness. Performance 80 cu. yd. Unit cost, cu. yd 22.6 ct. Daily Cost of Operation 1 runner .* $ 5.00 1 fireman 2.31 1 laborer 1.75 1 laborer 1.65 Supplies 4.50 Interest and depreciation, 17%% on $4,500 (approx.), based on 200 working days per year 4.00 Total $19.21 $19.21X565/600 = $18.10; $18.10/80 = 22.6 ct. per cu. yd. Process Analysis Per cent. Actual digging 35.8 Delays : A Sheeting trench before moving up 32.6 B Moving up 15.9 C Delay due to curve 15.7 100.0 */ji... . , ; ^ 0005000000 g S.2 x x x x xx Jfg, O 50 S- t- t- ? . Illllll fL| c8 030QOQ02CQ f ZL -*^ -*J -*^ -*J -*^> -*^> rt C55i5C^^ c o ^ W& 3OO METHODS AND COST OF TRENCHING 823 and deliver the excavated earth to a belt conveyor that carries the material to one side of the trench. These machines are made in two different models, and in two types of each model. Models K and K-O are illustrated in Fig. 18. In the K ma- chine the buckets travel automatically back and forth across the trench, thus cutting any width of trench between 22 and 42 in. without changing the size of the buckets. The model K-O is a very strong machine. Fig. 18. Design of Parsons Excavators, Models K-O and K. The daily cost of operating a $5,600 machine is estimated by the manufacturers as follows, based on a 10-hr, working day and 200 working days per year. Engineman $4.00 Fuel r 6.00 Oil and waste 1.00 Repairs, 5% 1.40 Interest, 6% 1.70 Depreciation, 15% 4.25 Total $18.35 The E and F machines are equipped with the oscillating de- vice enabling widths of trench from 28 to 60 or 72 in. to be cut without changing the sixe of buckets. The advantages of these machines are their adaptibility to all sizes of work, their rugged construction, short length, variety of digging speeds, and, in particular, their almost vertical digging boom that enables sheeting to be placed within 4 ft. of the rear of the machine. Steam driven machines require 1,200 to 2,000 Ib. of coal per 824 HANDBOOK OF EARTH EXCAVATION 10 hr. The first cost of machines is approximately $270 to $300 per ton of weight. These machines are made by The Parsons Co., Newton, Iowa. Cost of Work with Parsons Excavator. W. G. Kirchoffer, in Engineering and Contracting, Apr. 10, 1912, gives the following relative to the work of a Parsons trench excavator in sand, ' * * j^fii ,t--//ho7/ 00!. Design of Parsons Excavators, Models E and F. gravel and clay. The trench was 5,270 ft. long and was dug for an 8-in. sewer at West Salem, Wis. The trench averaged about 8 ft. deep. The total number of days' work put in on the job was 320, or an average of 61.8 days per 1,000 ft. of sewer. The trenching machine was operated 20 days out of the total 26 put in upon the work, or an average of 263^ ft. per day. The least distance made in a day was 20 ft. and the maximum dis- tarice of 550 ft. of completed sewer. There were five days in METHODS AND COST OF TRENCHING 825 which the rate exceeded 400 ft. of sewer per day. The progress diagram is shown in Fig. 21. The labor put in upon the work was divided as follows in days per 1,000 ft. of sewer: 1.092 4 935 4.315 4.270 ; 4 79 4.412 & ' r * 3 417 r, & 3.75 Mr v 1 993 V'.i. il 26.04 Tamper . 4.13 W. & Fig. 20. Parsons Excavator Model F Equipped with Backfiller. The greatest number of men employed in any one day was 16 and the smallest number was two. A man who was killed upon the work came in contact with some high tension wires in at- tempting to lift them over the excavator with a common broom stick when they were moving from one street to another. P. & H. Trench Excavators. These are of two types: The wheel -type in which the excavating buckets are fastened to the rim of a wheel, and the ladder type in which the excavating buckets are fastened to a chain belt traveling up a ladder. The 826 HANDBOOK OF EARTH EXCAVATION principle of the wheel-type machine is illustrated in Fig. 22. This type of machine is furnished in two general styles. The drainage type machine is built in 12 sizes, ranging from the No. 1 .exca vator capable of digging trenches 11.5 in. wide and 7.5 ft. deep. The contractors type machine ranges from the No. 13 capable of digging 15 in. wide by 5.5 ft. deep, to the No. 36 machine capable 403 800 1103 1600 2000 2400 2800 3200 3600 4000 4400 4600 4800 5000 #00 Length of Sewer Laid in Feet Fig. 21. Progress Diagram of Sewer Trenching by Machine at West Salem, Wis. of digging 54 in. wide by 12 ft. deep. The ladder type excavator is furnished in four sizes: as follows: Depth of cut, 10 ft. ; width of cut, 18, 24 and 30 in. Depth of cut, 12 ft. ; width of cut, 24, 30 and 36 in. Depth of cut, 15 ft.; width of cut, 24, 30 and 36 in. Depth of cut, 20 ft. ; width of cut, 24, 30, 36, 48, 60, and 72 in. These machines are made by the Pawling and Harnischfeger Co. of Milwaukee, Wis. Cost of P. & H. Machine Trenching for Water Mains. Engi- neering and Contracting, May 8, 1918, states that by using a trenching machine the Water Department of Erie, Pa., has over- come difficulties incident to the labor shortage and at the same time has effected a large saving in excavating for water main ex- tensions. A report on the work of the machine, furnished by Mr. E. W. Humphreys, Superintendent of Waterworks, shows that it has dug 5^ and 6 ft. deep trenches at a cost as low as 0.9 METHODS AND COST OF TRENCHING 827 ct. per lineal foot. This particular trench was dug in hard clay. The figure covers the wages of operator and helper and the cost of gasoline, oils and grease. In laying 10,000 ft. of 6-in. main in 1917 the cost of hand digging alone was 19 ct. per lin. ft., with common labor at 27^ ct. per hour. The hand dug trench was in clay with shale at the bottom. The accompanying tabulation shows work done by the machine Fig. 22. Detail of Wheel and Method of Digging Ditch, P. & H. Trench Excavator. at various times from May 1, 1917, to Jan. 3, 1918. The width of trench was 2 ft. Rankin Ave. N., running sand and gravel Rankin Ave. S., hard shale 22d W. Cranberry, hard clay 28th W. of Sigsbee, clam loam Cherry N. of 30th, clay and gravel 5th W. Raspberry, sandy .014 27th W. Cascade, hard clay '. 009 Old French Road, hard clay 009 Cost per lin. ft. ?0.065 .036 .010 .010 .012 The costs given in this table are the actual operative costs, exclusive of overhead, depreciation and repairs, and pay of watch- man. The costs in detail for three of the jobs follow: .HANDBOOK OF EARTH EXCAVATION Rankin Ave. N. (1,000 lin. ft. trench, 5.5 ft. deep) Per lin. ft. Operator, 62 hr. at 32V 2 ct $00200 Helpers, 115 hr. at 30 ct 0345 Gasoline, 39 gal. at 24% ct [0090 Oils, 4 qt. at 9% ct 0004 Grease, 2 Ib. at 1% ct .0001 Total (1,000 lin. ft.) $0.0640 Rankin Ave. S. (800 lin. ft. trench, 5.5 ft. deep) Per lin. ft. Operator, 26 hr. at 35 ct $0.0114 Helper, 38 hr. at 28 ct 0130 Gasoline, 35 gal. at 25 ct 0109 Oils, 4 qt. at HMs ct 0006 Grease, 1 Ib. at 9 ct 0001 28th W. of Sigsbee (652 lin. ft. trench, 6 ft. deep) Total (800 lin. ft.) $00360 J3 Per lin. ft. Operator, 3 hr. at 35 ct $0.002 Helper, 3 hr. at 27 ct 002 Gasoline, 12 gal. at 25 ct 005 Oils, 4 qt. at 11% ct. ; grease, 1 Ib. at 9 ct 001 Total (652 lin. ft.) $0.010 The costs on the last six jobs represent the actual time the machine was engaged in trenching. On the old French Road work 230 lin. ft. of trench was excavated in one hour, while in the 27th St. work 210 ft. of trench was dug in one hour. A sum- mary of the operating costs on the six jobs shows the following: 6 jobs trenching (2,727 lin ft., 5.8 ft. deep) Per lin. ft. Operator, 15 hr. at 39 ct $0.0021 Helper, 15 hr. at 31% ct 0017 Gasoline, 61 gal. at 25.1 ct 0060 Oils, 13 qt. at 11 ct .0005 Grease, 5 Ib. at 6% ct. 0001 Total (2,727 lin. ft.) - $0.0104 The trenching machine, a Pawling & Harnischfeger, was pur- chased by the Water Department early in 1017 at a cost of $5,650 f. o. b. Erie. Cost with a P. & H. Trench Excavator at Erie, Penn. En- gineering News-Record, Feb. 14, 1918, gives the following: Four miles of G- and 12-in. water-main trenches in wooded or frozen ground and with shale at the bottom were completed with a machine by the Water Department of Erie, Penn., between Feb. 1 and Oct. 5, 1917, at a cost far below that of hand work, even in 1915. Though at the speed developed by the machine, 3 to 3% ft. per min. on 5^- and 6-ft. deep trenches, this repre- METHODS AN1DI COST OF TRENCHING 829 sents less than two weeks' steady work, the difference in the amount paid for hand labor per foot in 1916 and in the cost per foot of all labor and fuel required with the machine represents more than half the first cost of the tool saved on the four miles already completed. It is doubtful if the extensions built in 1917, representing more work than was done in either of the preced- ing years, could have been completed without the machine because of the scarcity of labor. j tfji The trenching machine, a Pawling & Harnischfeger, bought early this year for $5,050 f.oJb. Erie, is of the wheel type. The buckets are adjustable for cutting 11$ to 54 in. wide and trenches 4} to 12 ft. deep can be dug. The machine is driven by a four- cylinder, four-cycle, 40-hp., gasoline engine. Ordinarily, one op- erator and one helper run it without other assistance under the supervision of the foreman who looks after the rest of the work. The trenches cut are 2 ft. in width and from 5^ to 6 ft. in depth. Clay 2 to 4 ft. deep, underlain by shale, is encountered on nearly all the work, though one trench has been dug in running gravel. Conditions are such that the machine cuts full length for the ex- tension to be laid in a continuous operation, most of the trenches being less than 2,000 ft. long. The pipe gang of 7 men lays the new main behind it at the rate of a block, or 660 ft., a day. As the water mains are always extended in advance of paving,, operations are completed by backfilling the trench with a team and scraper. In this manner li miles of 12-in. and 2^ miles of 6-in. pipe were laid between Feb. 1 and Oct. 5. During 1915, considered an ordinary year, the city laid 25,000 ft. of 6- and 12-in. mains in hand excavated trenches at a labor cost for digging, laying and backfilling of 29 ct. .a foot for the smaller and 36 ct. a foot for the larger size. Much more pipe was laid in 1916 and this year because of the rapid growth of the city. While complete unit costs for the last year's work have not yet been compiled, it is known that rising wages caused con- siderable increase over those of 1915. Records for 10,000 ft. of 6-in. main laid at one time last year show a total labor cost of 37 ct. per ft., of which digging alone represented 19 ct., with com- mon labor 27} ct. an hour. The trench was in clay, with shale at the bottom. As compared with this, the first performance with the trenching machine, excavating for 1,620 ft. of line, was accomplished at a fuel and labor cost of 8.2 ct. per ft. for actual digging. This was in gravel which required sheeting, the cost of which is included in the above figure. On another occasion, in digging through cut-over land, where many large but partly rotted stumps were cut through, 682 ft. of trench was dug in four hours, at a cost of $7.55 for three men and 15 gal. of gasoline 830 HANDBOOK OF EARTH' EXCAVATION only 1.1 ct. per ft. On Oct. 5 the machine made its speed record of 660 ft. in three hours, $3.02 for gasoline and $1.88 for the wages of the engineer and helper being charged to the operation. This was about 0.75 ct. per ft. Both trenches were in shale at the bottom. That these costs are typical of the work is shown by the record which the machine made on its most difficult bit of digging. Last winter, with 18 in. of ground frozen hard, it dug in one oper- ation 7,220 ft. of 2 x 5^-ft. trench at an average speed of 3 ft. per minute. The bottom of this trench was in shale, the average depth of which proved to be 44 in. Over most of the trench the clay was frozen to the top of the shale. This shale is not laminated clay, but a true shale, which can be picked in excavating bell holes, but which it pays to shoot when any considerable yardage must be removed by hand. Excavating and Backfilling by a Carson Trench Machine. The following data are taken from Engineering Record, Jan. 2, 1915, relative to sewer work in Vancouver, B. C. The machine is designed to be set up over a 340-ft. length of trench, from which excavated material is loaded directly into buckets, which elevate it, run back along the trench and dump it as backfill over pipe already in place. It is obvious that the pipe must be laid at the same rate as the excavation advances. The buckets are operated by cables running through carriers on an overhead rail, which is supported over the center line of the trench and 12 ft. above the surface of the ground by nineteen wooden trestles. Each trestle is mounted on two wheels, one on each side of the trench, which rest on the rails of an 8-ft.-gage track. This track carries the engine as well as the entire 340-ft.- length of framework, thus greatly facilitating moving ahead as work advances. Excavation is carried on simultaneously in two 48-ft. lengths of the trench, a gang of six men working in each. The machine is equipped for handling six ^-cu. yd. buckets at a time, so that by keeping 18 buckets on the job, a set of empties is always left in the trench when full ones are removed, and the workmen need never wait while buckets are being dumped. Under this plan each man has an 8-ft. length of trench to work in, and fills his bucket independently of others. When loaded buckets are hoisted to the limiting position they are automatically locked to the car- riers, which are then drawn along the overhead rail to the point where the fill is being made. Here the buckets are dumped sep- arately by a lockman, who moves along the bucket line on a plank walk supported by the trestles. This lockman signals the engineer for each move, and is the only man required on the METHODS AND COST OF TRENCHING 831 bucket line, the empty buckets being taken from the cables and full ones substituted by the workmen in the trench bottom. The work of taking down the machine, moving to another job and setting up again ordinarily requires three to four days' time with a crew of 10 men. Thus with a haul of, say, 1 mile, the total cost of removing from one setup to another is about $170. Canvas Troughs. When small trunk or lateral sewers were un- covered for any considerable length in excavating the trench, temporary provision was formerly made by carrying the flow during construction in open wooden troughs fixed to the side of the trench. It was found, however, that, besides being expensive to handle and move, these flumes interfered with the work and caused frequent trouble which could be entirely eliminated by the use of closed canvas troughs. The latter were made by simply affixing eyelets to opposite edges of a strip of heavy canvas of any desired width up to 3 ft. Eyelets on both edges of the strip are then hung on the same set of spikes driven into the timbering on the side of the trench and placed, roughly, on a fairly steep grade. This type of trough is often strung for the full 340-ft. length of the trench, and the laterals encountered are connected to it by short lengths of similar tubing. Timbering Methods. A considerable quantity of timbering is taken from job to job with the machine, breakage being replaced as required. It has been found, however, that with the system now in use the breakage is almost negligible. For all classes of soft material l^xlO-in. sheeting is used in 4-ft. lengths, and it has been found that this works to much better advantage than the longer sheeting, which would require driving. When the trench has reached a depth slightly over 4 ft. digging is stopped while the timbering is placed. The diggers all help in placing the timbering, at least until the stringers are braced in by jacks, after which excavation is re- sumed, while the man detailed to look after t the timbering sets the struts and lines up the timbers generally. This man spends all his time attending the timbering, carries it forward as fast as it is removed from the backfill and lays it along the trench where it will be needed in new excavation. Thus, when a new set of timbering is required, all material is ready to be passed down by the timberman, and as the work-men do not have to leave the trench, the entire operation of placing timbering in a 48-ft. section 4 ft. deep delays the work only about 20 min. One 3x 12-in. stringer is placed midway of each sheeting set, and opposite stringers are braced by 4 x 4-in. struts, spaced on 8-ft. centers. When nearing the depth at which sheeting will no longer be required the sheeting is changed from 1^-in. to 1-in. 832 HANDBOOK OF EARTH EXCAVATION material, which still further reduces initial cost and cost of handling. Crew. Exclusive of supervision, 17 men operate the machine. These include 12 pick-and-shovel men filling buckets in the trench, one lockman, one engineer, one timberman, one toolman and a straw boss. Only half of the superintendent's time is charged against the machine, as he ordinarily looks after two jobs. In addition to the machine crew, a gang of four men is used in laying sewer pipe. Whenever the pipe crew gets behind with its work some of the diggers are set to helping with the pipe or con- crete; and, vice versa, when the pipe crew has extra time it is used in the trench ahead. Thus it is possible to equalize any deficiency in forces or to compensate for unforeseen difficulties in either branch of the work, a flexibility which is considered a great aid to efficiency. Cost Data. In order to give a fair idea of actual capacity of the machine and the cost of operation, a typical case has been selected in which about 7,700 cu. yd. were handled in a 2,700-ft. trench excavated for a 2-ft. trunk sewer. This work was done in Granville Lane, Vancouver, which has a width of 20 ft. A start was made on the lower end of the trench, hand labor being used until a depth of about 8 ft. had been attained. The machine was then put in service and used until the job was finished. The maximum depth of the trench was about 26 ft. The trench has a top width of 4 ft., which was maintained until a depth of 12 ft. 6 in. was reached, below which no timbering was used, and the width gradually decreased to 3 ft. at the bottom. The work was begun in the fall of 1913 and continued without interruption, using one 8-hr, shift. The average volume of excavation handled in 8 hr. was 45 cu. yd. A careful distribution of the costs on this work gives the following results: Per cu. yd. Labor (including superintendent and watchman) .... $1.63 Hauling machine to the job ($88) 0.0115 Erecting and taking down machine ($96) 0.0125 Upkeep of plant 0.0428 Running expenses 0.1126 $1.81 Depreciation of plant 0.04 Interest on cost of machine at 5% 0.02 Total per cu. yd $1.86 The last two items in the table are values assumed for the city of Vancouver, and might be quite different under other circum- stances. The life of the machine was assumed at 10 yr., it being assumed that in city service it would last much longer than in METHODS AND COST OF TRENCHING 833 ordinary contracting service, and 5% is the rate at which the city secures money for such purchases. It should be noted that only one haulage charge is made in these . figures. This is be- cause the machine is kept busy continually by being moved from one job direct to another. In contractors' service, if the machine were returned to the storage yard after each job, the haulage item would be doubled. The labor item, which is so large a pro- portion of the total, is based on the following labor costs per hour for an 8-hr, day: Pick-and-shovel men, 40 ct.; timberman, 42i/ ct.; lockman, 42} ct. ; steam engineman, 53i ct.; toolman, 371^ ct. ; straw boss, 42^ ct., and one-half superintendent's time, 62i ct. " Upkeep of plant " includes ordinary wear and tear, as well as minor breakages, while " running expenses " includes coal, water, timber, tool sharpening, etc. Two items which might have to be included under other circumstances are em- ployer's liability insurance and excess spoil haulage the latter in cases where excavation and fill could not be figured to bal- ance. The question of minimum trench depth at which the machine would be efficient has been worked out for Vancouver labor price as about 8 ft. for the usual case. However, if the job was com- paratively short and the haul very long, a depth as great as 12 or 14 ft. might be the minimum. A feature that, tends to make pick-and-shovel men efficient, or at least keep them all up to a uniform standard, is the fact that no one can do less than the others without having this known, since all six buckets come up at once; when one man is slower than the others he will still be working while the remainder of the crew wait. It is to be noted that in practice this generally works out so that after the first few days on a job there is remarkable uniformity in the time the men require for filling buckets. The machine used in Vancouver was purchased early in 1911 for $5,000, duty paid, and was made by the Carson Trench Ma- chine Company of Boston. Cost with Austin Trench Excavators. Ernest McCullough gives the following data relating to work done by the " Chicago Trench Excavator," a machine made by the F. C. Austin Co. of Chicago. The machine consists of an endless chain provided with cutters and scrapers which deliver the earth onto a traveling belt, the ex- cavators and conveyors being carried by a four-wheeled traction engine, which furnishes the power. In laying ~y 2 miles of pipe sewers at Marshfield, Wis., the daily cost of operating the machine and laying pipe was as follows: 834 HANDBOOK OF EARTH EXCAVATION Operator of trench digger $ 3.00 Engineman of trench digger 2.75 Fireman of trench digger 2.25 Man trimming bottom of trench 2.25 2 men bracing trench with plank 4.00 2 pipe layers, at $2.50 5.00 2 men furnishing pipe and mortar 4.00 2 men tamping earth around pipe 4.00 1 man shoveling earth down to the tampers 2.00 2 teams and drivers scraping backfill 7.50 4 men holding the scrapers 8.00 Total labor per 10-hr, day $44.75 About % ton of coal was used daily. The trench was 27 in. wide and averaged 7 ft. deep. The best day's run was 850 lin. ft. of trench, or 500 cu. yd. in 10 hr., in dry clay containing no stones. On another day nearly 500 ft. were run in spite of many stops to blast out boulders. A fair average was 400 to 500 lin. ft., or 300 cu. yd. per day. Due to the jarring of the ground by the machine it is necessary to brace the trench. I am informed by Mr. McCullough that records of 650 cu. yd. per day have been made with this machine. These trench excavators are made in four sizes to excavate from 14 in. to 60 in. in width and up to 20 ft. in depth. As confirming these data of Mr. McCullough's, the following records given by Mr. B. Ewing are of value: In the summer of 1904, many miles of pipe sewers were built at Wheaton, 111., by contract. Two Chicago (Austin) Excavators were used, cutting a trench 2^4 ft. wide, 7 to 18 ft. deep. One machine would ex- cavate 750 lin. ft. of trench 7 ft. deep through hard clay mixed with small stones, in a 10-hr, day. In cutting trenches 15 to 18 ft., a machine would average 150 to 200 lin. ft. per day, depending upon how much' bracing was necessary. Use of an Austin Excavator at Moundsville, W. Va. The fol- lowing data are from a paper by A. W. Peters, in Engineering and Contracting, Feb. 28, 1912. The work entailed the construction of 3.5 miles of trench to 6 ft. deep, 16.5 miles 6 to 8 ft. deep, 3 miles 8 to 10 ft. deep, and 3 miles deeper than 10 ft. As labor troubles developed, and as the conditions were suitable to machine work, a No. 00 Chicago sewer excavator was installed. This machine was fitted with buckets 22 in. wide, and had a separate set of buckets 27 in. wide. The length of arm was 8 ft. but there was an extra 2 ft. extension that enabled the machine to dig 10 ft. deep. The soil was excellent for machine work, consisting mainly of fine sand mixed with loam and unstratified yellow clay, moist enough to stand well with occasional vertical braces. Where sand predominated the machine had a large output, but where clay predominated the speed was much slower. METHODS AND COST OF TRENCHING 835 The backfill was divided into two operations: (1) Filling in and tamping by hand 1 ft. of earth covering. This cost about 16 ct. per cu. yd. (2) Filling in the remainder of the trench. This was done with a Sydney scraper and team. Tamping was ac- complished by flushing the trenches with water from hydrants. Two men followed the scraper cleaning out the gutter and round- ing off the fill. The cost of the backfill scraper work per day was as follows: -: -Xf'i'it! .15 C.J Team and driver $ 4.50 Helper on scraper 1.75 Helper on hose, etc 1.75 Cleaning up gutter, 2 men at $1.75 3.50 Water, 5,000 gal., at 10 ct. per M 0.50 Per day of ten hours : $12.00 The average daily yardage of backfill was 280 cu. yd. at a cost of 4.4 ct. per cu. yd. The best day's work was 380 cu. yd. The daily cost of trench excavation with the machine was as follows : Operation : Superintendence $ 1.50 Engineman and helper 4.75 Watchman " 1.75 Coal, 15 bu. at 7 ct 1.05 Water, 1 single team 2.50 Plumber, service pipes, average 1.00 Total per day $12.55 Sheeting: Uprights and jacks; no rangers. 2 men at $1.75 $ 3.50 Lumber, used repeatedly, neglected. Maintenance : Replacing dull spuds on buckets $ 0.50 Engineman's time Sunday cleaning up, $3.00/6.... 0.50 Total maintenance *. $ 1.50 Depreciation : Life of machine figured at 5 years, 9 months to the year, 25 days to the month $ 4.00 Daily total (10 hr.) $21.55 In 23 days 4,100 cu. yd. were excavated, at a cost of 12.1 ct. per cu. yd. ; but the actual digging time was 203 hr. The best day's work was 321 cu. yd., at a cost of 6.7 ct. ; and the poorest day's work was 82 cu. yd., because of bad banks, at a cost of 26.2 ct. Cost with an Austin Excavator at Glencoe, 111. Engineering and Contracting, Apr. 5, 1911, gives the following by Don E. Marsh, relating to a sewer system constructed at Glencoe, 111., 836 HANDBOOK OF EARTH EXCAVATION beginning August, 1910. The lengths and depths of the various sizes of sewers are as follows : 15,500 lin. ft. of 8-in. pipe. 8 to 12 ft. cut. 5,600 lin. ft. of 10-in. pipe, 7 to 13 ft. cut. 250 lin. ft. of 18-in. pipe, about 13 ft. cut. 1,000 lin. ft. of 15-in. pipe, about 16 ft. cut. 4,700 lin. ft. of 18-in. pipe, from very shallow to 30 ft. cut. The soil, especially in the deep cuts, was hard clay, the top 15 ft. being a brownish clay with some traces of sand, and the remainder a hard blue clay. During the fall and winter months this soil became extremely hard and difficult, and could not be dug by hand without the aid of a pick. This was an advantage in some respects as it obviated the need of sheeting. During part of the work there was frost in the ground to a depth of 14 to 16 in. A small amount of the excavating was done by hand, but the greater quantity was performed by two Austin sewer excavators. The large machine dug trenches 33 in. wide and up to 25 ft. deep. Before digging trenches of originally greater depth than 25 ft. the street was graded down 3 or 4 ft., and the remaining foot or two left by the machine in the bottom of the trench was exca- vated by hand, the dirt being thrown on the boom of the exca- vator or on the completed pipe line. The smaller machine dug to depths as high as 15 ft. The sides of the trench were left vertical and smooth. Vertical planks 13 ft. apart in deep trenches and less in shallow cuts, with extension screw braces, were used for bracing. At only a few points was caving experi- enced. The cost of backfilling was excessive, as it was done by hand. An automatic backfiller was tried, but as this makes it neces- sary to keep the pipe laid close up to the boom of the machine its use was abandoned. From records of a few average days the cost of labor in trenches 25 ft. deep was about as follows, with an average prog- ress of 80 lin. ft. per day, or 200 cu. yd. 1 foreman $ 8.00 Excavating machine, including operator 40.00 1 engineman 4.00 1 fireman 3.00 5 trenchmen at $3.00 15.00 20 laborers, backfilling, at $2.50 50.00 2 teams at $6.00 12.00 Coal 5.00 Repairs and sundry expenses 10.00 Total per day $147.00 This is equivalent to $1.86 per lin. ft., or about 73 ct. per cu. yd. METHODS AND COST OF TRENCHING 837 Work of Austin Excavator in Shale. The following data give the comparative costs of trenching for 3C-in. pipe through fairly hard New .Jersey shale. The material was of such nature that it could be picked and shoveled. The total cost of trenching, lay- ing, calking, and backfilling, including the cost of small tools, plant charges, etc., except the pipe itself, foil 7 miles of 36-in. pipe was $1.10 per foot. Records taken of the cost at various times gave the following results: Work during two weeks of 8 working days in September, trench 4 ft. wide by 6 ft. deep, total pipe laid 2,412 ft., an average of 301 ft. per working day. The cost was as follows: Rental of machine $0.144 Labor, coal, teams 0.1 40 Total per lin. ft. $0.294 Work during 5 working days, trench 4x6 ft., total pipe laid, 1,944 ft., an average of 389 lin. ft. per working day, at a cost as follows : Rental of machine $0.130 Labor, coal, teams 082 Total per lin. ft $0.212 Work by hand on same job, trench 5 ft. 10 in. by 4 ft. 4 in., cost of excavation and backfill, $0.826 per lin. ft. Laying and calking cost $0.143, and lead cost $0.285 per lin. ft. Work of an Austin Trench Excavator. This excavator equipped with caterpillar traction, was used to excavate a portion of the trenches for underground telephone trunk lines between Washing- ton and Philadelphia. According to Engineering News, May 25, 1911, the machine excavated daily 1,000 lin. ft. of trench 1.5 ft. wide and 3 ft. deep. The capacity of the machine was found to be about 3 ft. of clean trench for each minute of working time. Again in Engineering News, Aug. 6, 1914, daa are given on an Austin Trench Excavator which was used to excavate a water-pipe trench, 6 ft. wide by 6 ft. deep, through various kinds of ma- terials, mostly gravel. In the actual operating time of 122 hr., 5,035 ft. of trench was excavated. The operating cost of the ma- chine was about $15 per day. Excavation in Chicago is described in Engineering and Con- tracting, July 17, 1912, as follows: An Austin No. 1 trench ex- cavator equipped with buckets cutting 42 in. wide, was used in 1912 to excavate black loam and underlying blue and yellow clay. The average depth was 14 ft. Sheeting was composed of vertical planks set 2 ft. apart. The sewer was a 36-in. circular brick sewer, and it was necessary for three men to pick and undercut 838 HANDBOOK OF EARTH EXCAVATION the sides and trough the bottom after the machine. The daily cost of operating the excavator was as follows: <;\ '&>' i *' ' ! ' ! ^ 'ii^'i" !*Mi'"it; '.;, ; (j;i i.'jljjfi; -;\\l ')fi - tife /<>i"1 Engineman $ 5.00 Fireman 2.50 C9al, % to 1 ton 4.00 Oil and waste 0.50 Total per day $12.00 The speed of the machine was regulated by the rate of brick- laying, the force employed on that part of the work being 30 men. From June 3 to July 8, 1,600 ft. was excavated but the machine had made runs on two favorable days of 184 ft. and 170 ft. Cost with Trench Excavators at Alton, 111. J. E. Schwab in Engineering and Contracting, Feb. 10, 1915, gives the following: In the construction of this sewerage system there were used one small 00 Austin gasoline ditching machine which excavated a ditch 24 in. wide. The following output data were furnished by G. M. Johnson, of the Lillie Construction Co., sub-contractors, and owners of this machine: Total amount of work done, lin. ft 19,800 No. of working days 90 Average cut per day, lin. ft 220 Maximum cut per day, lin. ft 800 Average cost per day for operation $30 Average Cost Per Foot for Laying Pipe. Ct. Operation of machine 13.6 Kj.ji,! incidentals 1.4 Total cost, per foot for excavation 15.0 Laying pipe 4.0 Refilling 3.0 Excavating, laying pipe, and refilling trench 22.0 Cost of cu. yd. of excavation ...J. i 18.4 Depth of trench averaged *11 ft., with a maximum of 22 ft. and a minimum of 4 ft. There was also used a Parsons steam ditching machine with backfiller, which excavated a ditch 28. in. wide. The following figures as to the work done by this machine are only approximate : Total amount of work done, lin. ft 18,000 Number of working days 90 Average cut per day, lin. ft 200 Average cost per day for operation, laying pipe, and backfilling ?45 Average depth of trench excavated, ft H^ The balance of the main line sewer, where conditions were un- favorable for the use of excavating machines, and all laterals were put in by hand gangs. . METHODS AND COST OF TRENCHING 839 The Buckeye Traction Ditcher. This excavator consists of a traveling engine equipped with a vertical digging wheel at the rear. This wheel is fitted with digging buckets of any of three types: The gumbo or open bucket for sticky soils; the solid or closed bucket for dry soils; and the combination contractors' bucket with cutting teeth for general hard work. To insure a clean ditch a shoe or runner, carrying the weight of the wheel, is drawn back of the cutters. The machine reaches the full depth at one cut and leaves the bottom at grade. It may be fitted with wheels or with caterpillar traction. Most of the machines are furnished with gasoline engines but the larger machines may be obtained with steam power. 23. Buckeye Traction Ditcher, 14i-in. x 4i-ft. Machine with Apron Traction. These machines range in size from the No. 0, cutting 11.5 in. wide and 4.5 ft. deep, and the No. I, cutting 11.5 and 14.5 in. wide and 4.5 ft. deep, to the No. 10 machine, cutting 28 and 30 in. wide and 12 ft. deep. They weigh from 7 to 38 tons and cost from about $240 to $280 per ton in 1916. Caterpillar wheels cost about $30 per ton of weight of the entire machine, extra. The caterpillar traction machine with wheel raised is shown in Fig. 23. These machines are made by the Buckeye Traction Ditcher Co., Findlay, Ohio. Cost with a Buckeye Traction Ditcher. Engineering and Con- tracting, Feb. 12, 1908, gives the following: Thirty-six miles of trenching was excavated for a wooden pipe line for the water system at Greeley, Colo. About 2,000 ft. in rock was excavated by hand, and the remainder in earth by a. 840 HANDBOOK OF EARTH EXCAVATION Buckeye 28-in. x 7.5-ft., 17-ton, drainage machine. Eight miles of trench was through gravel containing many stones, with some cemented gravel. The remainder was in clay, rather hard. The average number of linear feet per day was (527, or 222 cu. yd. In 10 hr. the machine dug from 000 to 1,000 lin. ft. in gravel, and up to 2,500 ft. in clay, while actually working, the trench being 30 in. wide and 4 ft. deep. The daily cost of the work was as follows: Engineman $5 3 helpers at $3 . , 9 Coal, 1 ton at $5 5 Plant charges 6 Total per day $25 About 1 gal. of water per pound of coal is consumed. The " plant charges " are estimated at 30% annually on a $5,200 excavator, and 250 days worked annually. On this basis the cost of 300 days' work averaged 4 ct. per lin. ft., or 10.7 ct. per cu. yd. Costs of Tile Draining with a Buckeye Machine. At New London, 0., a 14.5-in. x 4.5-ft. machine was used to drain a 1,000- acre farm. Twelve miles of ditches were dug during 1910. The cost of operation per 100 lin. ft. was as follows: Man to run machine $0.18 Man to lay tile 0.24 Fuel: gasoline at 13 ct. per gal 0.11 Repairs: parts and labor 0.14 Oil and grease 0.01 Total per 100 lin. ft $0.68 The ditches averaged 2.5 ft. in depth. The soil was clayey and during the dry season was hard digging, and in wet weather very sticky. The apron wheels enabled the machine to be successfully operated in swamps that could not be crossed by teams. Ditches dug by hand the previous season cost $2.40 ct. per 100 lin. ft. Excluding the wages of the men laying tile, the cost was 44 ct. per 100 lin. ft., or less than 4 ct. per cu. yd., exclusive of interest and depreciation. Cost of Tile Trenching with a Machine. A machine made by the Buckeye Traction Ditcher Co., of Findlay, Ohio, was used on the Northwest Experiment Farm, University of Minnesota, in 1903. The machine dug a trench 14i in. wide and 4i ft. deep. It had an 8-hp. boiler and consumed 450 Ib. of coal and 4 bbl. of water per day. It dug 34,000 lin. ft. of trench in 45 days' actual working time, or 744 lin. ft. per day. The men who handled the machine were inexperienced. METHODS AND COST OF TRENCHING 841 The following was the cost: Per 100 ft. Labor running machine $0.45 Coal at $7.50 per ton 0.19 Water 0.13 Oil 0.01 Repairs 0.13 Total ditching $0.91 Laying tile 0.18 Blinding 0.05 Incidentals 0.09 Totals | $1.23 The price of the machine was $1,400. Although the machine was not well handled and had not at that time (1903) been perfected, it made a very creditable record of cost, as contrasted with hand work, for the latter cost $3.88 per 100 lin. ft. on the same farm. Two men operated the machine. I recently saw a machine of the same make and size on a farm in New Jersey where it was averaging 2,000 lin. ft. of trench (15 in. x3 ft.) in 10 hr. Tile Trenching with a Buckeye Ditcher. The following is from an abstract of Bulletin 110 of the University of Minnesota by Engineering and Contracting, Oct. 21, 1908. A Buckeye Traction Ditcher, which cut a trench 4i ft. deep and 14i/ in. wide, had been sent to the farm in 1903 for dem- onstration purposes, and was used throughout the season. This machine consists of a four-wheel truck, 4 ft. wide and 12 ft. long. The distance between the wheel centers is 6 ft. 4 in., and 7 ft. between front and real axle. The rear axle serves as a drive shaft and is geared to the engine shaft by chain belting. On the front end of the truck is placed an 8-hp. vertical boiler, and immediately back of the boiler is a 6-hp. Dingle engine. At- tached to the rear of the truck is a frame carrying the cutting wheel. This machine, in 63 days of which 45 were working days, dug 33,498 lin. ft. of trench, an average of 744 ft. per working day. The machine was operated at its lowest working speed, which would cut 100 ft. of trench in 32 min., but unavoidable delays cut down the daily run. At wet spots planking was required beneath the traction wheels, and trouble at the places caused much delay. The earth collected on the elevator rollers, and the grass roots sticking on the knives made it necessary to clean them after every 35 or 40 ft. This latter trouble was partially remedied by turning two furrows with a breaking plow along the side lines of the proposed trench. Another difficulty was 842 HANDBOOK OF EARTH EXCAVATION caused in wet soil by the shoe rolling up the soil from the bottom of the trench, and necessitating hand dressing with a scoop. The machine as a rule required the services of two men, one to at- tend the boiler and engine and another to look after the ratchet wheels that control the line and grade. The coal consumption averaged 60 Ib. per 100 ft. of trench, varying from 50 to 80 Ib. according as the weather was cold or warm and varying with the nature of the soil. I his coal was carried in the water tank and its conveyance to the work is charged to water account. About 9 bbls. of water were carried per tank load. This water was placed in barrels along the trench, one barrel per 200 ft. being required. The speed of the machine in moving from one job to another, including the time lost while taking on coal and water, was about % mile per hr. As the machine could not make curves of shorter radius than 300 ft. it was necessary to start most of the ditches with hand work. Table I gives the cost of three examples of trenching with the machine. Example 1 is the cost of digging 8,750 lin. ft. of trench in 13 working days. In this time the machine was laid up three days for repairs, the actual time worked being 10 days. The average run was 875 ft. per day. This example represents aver- age conditions and shows what the machine can do in average soil. TABLE I COST OF TRENCHING AND TILLING 100 FT. Labor of running machine. Coal Example 1 Example 2 . $0.457 $0.409 .. 0.188 0190 Example 3 $0.516 0.263 Water . 126 087 0.126 Oil . . 0.012 0.010 0.014 112 100 0.200 183 212 0.235 Blinding . . 0.048 0.053 0.062 092 015 0.012 Total per 100 ft $1.218 $1.076 $1.428 Coal cost $7.50 per ton delivered at the farm. Example 2 represents more favorable conditions. The soil was dry, the sod thin, ahd the work was closer to headquarters, requiring less time for the men in 'going and coining back and forth. There were 400 ft. of trench at the outlet ends of two ditches that exceeded 4.5 ft. in depth. These sections were dug by hand. On five other ditches there were from 100 to 200 ft. at the outlets that exceeded 4.5 ft. in depth, and over these the machine excavated to its full working depth, the bottom of the trenches being dug to grade by hand. This extra cost of hand work is METHODS AND COST OF TRENCHING 843 not shown separately but is added to the machine account. The total length dug in this section was 10,450 ft. Example 3 gives the cost of 14,298 ft. dug in wet soil covered with broken sod. Two ditches were in wild sod that had never been broken. The average cost of trenching, tile laying, and blinding for all machine work was $1.25 per 100 ft. This compares very favorably with the cost of digging 100 ft. of the same sized trench by hand, which cost was $3.88 per 100 ft. The machine did not work as rapidly as was expected, and there were more delays from breaks than looked for. However, the soil is difficult to work, being much slower to handle by either spade or scraper than in many localities where tile work is done, and many of the delays were due to the nature of the soil, although the work was performed at the favorable season of the year. The best condition for machine work would be in dry ground which is in cultivation, the drier and harder the soil, the speedier can the trenching be done. The machines which have been made during the past season have a number of improvements over the one used. It is believed that many of the difficulties with this machine would not be ex- perienced in one of the later models. On account of the scarcity and high price of labor, the tiling system could not have been completed this season if the machine had not been used, and the cost of work done would have been much greater. The machine was operated and all the work in connection with it was done entirely by farm help. The foreman operated the machine the greater part of the time. When the machine was laid up for repairs, the help was used on other farm work, the rules for a day's work on the farm being that the men should leave the barn at 7 and 1 o'clock and arrive at the barn at 12 and 6 o'clock. In the foregoing table of cost per 100 ft., no allowance was made for the first cost of machine. This machine, if bought new, would cost $1,400. As it was a machine, which had been used by the factory for demonstration purposes, it was considered as a second-hand machine and was secured by the state at much less than the original cost. An estimate of the deprecia- tion of machinery or interest on the investment is not considered in the cost of the work. The Havland Tile Ditcher. This machine, Fig. 24, is designed for ditching and tiling wet farm lands. The outfit consists of a tractor that draws a ditcher or excavator, and is made in two sizes known as the single wheel which has a single digging chain and the double wheel which has a double digging chain. Both ma- chines have caterpillar traction. Four-fifths of the weight is 25 844 HANDBOOK OF EARTH EXCAVATION to 40 ft. ahead of the ditch bottom. Tile can be laid accurately to grade. The diggers or shovels are fastened to a chain belt, and are so arranged that when the shovel strikes a stone or other unyielding obstruction the chain buckles and allows the shovel to travel over the obstruction. Shovels are made as wide as 42 in., and each shovel and reamer is automatically cleaned. The reamer regulates the width of excavation. The earth is thrown to one side by belt conveyors. Behind the digger in the ditch is drawn a sheeting form which prevents the bank from caving until the tile has been laid. Tile up to 12-in. diameter is laid automatically through a spout; tile 14 to 30-in. diameter is laid by hand. The dimensions of the machines are as follows: Length of tractor, ft Width of tractor, ft Length of ditcher, ft , . . Width of ditcher, ft Shipping weight, Ib Engine horse power Price Tile, diam. lin. ft. deep Capacity, 10 to 12 ft. deep. ft. per hr. Capacity, 6 to 8 ft. deep, ft. per hr.. . Capacity, 3 to 6 ft. deep, ft. per hr... Road speed, miles per hr Single wheel 22 10 26 10 34,000 45 $4,500 10 to 20 30 to 50 60 to 100 100 to 150 1 Double wheel 22 10 26 10 44,000 45 $6,000 14 to 30 25 to 40 75 to 100 1 Fig. 24. Havland Tile Ditcher. The crew required consists of 4 to 6 men of whom one is fore- man and one engineman. With a single wheel machine and four men 1,200 ft. of 8-in. tile has been laid 6 ft. deep in one day. At the same place six men laid 150 ft. by hand to the same depth. The labor cost by hand was $12.60 per day. The labor, gasoline and oil for the machine cost $10.50 per day. It is claimed that tile can be laid by these machines under conditions such that it is impossible to lay by hand. This machine is made by the St. Paul Mfg. Co., St. Paul, Minn. METHODS AND COST OF TRENCHING 845 Use of a Trenching Excavator on Marsh Land. In Engineer- ing and Contracting, Oct. 30, 1012, the methods and cost of con- structing a 48-in. wood stave pipe line across marsh land in Atlantic City, N. J., is given. A Parsons Trenching machine excavated 2.5 ft. deep and 6 ft. wide in a trench filled with water, at a rate of 500 ft. per day. The machine was carried on 4 x 12-in. planks, 12 ft. long, laid cross-ways of the trench, with 4 x 6-in. plank, 20 ft. long, laid on the top for the traction wheels to rest on. This work cost 20 ct. per ft., coal cost $5 per ton and was carried to the machine across the marsh by hand in 50-lb. sacks. Water was rolled in barrels across the marsh i mile to the ma- chine. Trenching by hand, cutting a ditch 8 ft. wide, trimming bottom and sides, the men in the ditch standing on a movable platform dragged along with them, cost ct. per cu. yd. All spoil was thrown to one side. Backfilling the pipe cost ct. per ft. Pump- ing cost 10 ct. per ft. The cost of constructing an embankment 18 in. thick on top and 2 ft. wide on the sides over the pipe, to a width of 6 ft. at the top and 12 ft. at the meadow level, all the material being taken from the meadow, 16 ft. from the center of the pipe, cost 23.1 ct. per ft. The trench had to be cut even and graded to act as a drain for the water in the pipe trench. The daily cost of the embankment was as follows: 1 foreman $ 4.00 1 sub-foreman 2.50 15 laborers at $1.75 26.25 1 waterboy 1.00 Cost of sharpening tools 1.00 Total, 150 ft. per day , $34.75 Excavation foremen received $3.50 per 10-hr, day, pump men, $3.50, and watchmen, $2.00. Trench Excavation by Hydraulicking. In Engineering Record, Nov. 8, 1913, Joseph Jenson gives the following: Excavation for the puddle core-wall trench for the Sevier River Dam of the Otter Creek Reservoir, Utah, was started by a con- tractor with teams and scrapers. The trench was specified to be not more than 25 ft. in width at top and 15 ft. at bed rock, and a depth of about 30 ft. The material was a mixture varying from silt and quicksand to gravel, boulders, and very large rock frag- ments. No timbering was used and the trench caved until it was 40 ft. wide at the top, and the rate of caving in and sliding down was equivalent to the rate of excavating the material. The con- tractor was relieved from further operations in August, 1910, a year after signing the contract. 846 HANDBOOK OF EARTH EXCAVATION Work was then resumed by the State. Vertical sheeting, driven in 4.5 ft. stages and braced horizontally at the top of each stage, was used. The closeness of the braces (4.5 ft. each way) pre- vented the use of plows, scrapers, or cars at the bottom of the trench. It was therefore decided to loosen the material with a water jet, and to wash it along the bottom of the trench to a point where the fine materials could be drawn up by a pump, the coarse materials being handled by dump boxes and derricks. The plant consisted of 12,200 ft. of 16-in. wood stave pipe-line placed underground, a small electric-power plant with house, transmission lines, motor and pump settings. Water was obtained at an elevation of 430 ft. Above the power house a 75-kw. dy- namo, operated by a Pelton wheel, furnished power for a 75-hp. motor driving a 12-in. Gould pump. A 4-in. wrought-iron pipe from the main pipe ran along the trench bank and fed two hose- lines at the ends of which were fire-nozzles. The pressure of the water jet at the nozzles was 180 to 200 Ib. per sq. in. The pumping and hoisting plant cost $7,322, which does not include the cost of the power pipe line which was charged to the con- struction of the hydraulic filling of the dam. In operation it was necessary to furnish additional water to the trench in order to keep the 12-in. pump supplied. The material was loosened and washed by the nozzlemen, the fine materials be- ing forced to the pump and the coarser being left in piles along the trench. These latter were loaded by shovels and forks into dump boxes and hoisted by a derrick operated by teams on a whip cable. The cost of excavating 8,000 cu. yd. was $2.90 per cu. yd. to which must be added the first cost of the plant less its salvage value, $4,322, making a total of $3.43 per cu. yd. Methods of Sheeting and Bracing. The following is from an article in Engineering and Contracting, Aug. 4, 1909. Trenches of slight depth, 3 to 4 ft., even in sandy soil do not, as a rule, require bracing. Saturating the soil with water will often enable sand banks to stand up for some little time. Trenches over 4 ft. in depth usually require bracing. The change of moisture con- dition of the exposed soil, as well as the load imposed by the ex- cavated material and passing laborers, is apt to cause a trench to cave, no matter how solid it looks when first excavated. The simplest form of bracing, suitable for trenches of from 4 to 7 ft. in depth, consists of a board placed horizontally along each wall of the trench. These boards are held against the trench banks by braces wedged between them. Deeper trenches require more elaborate protection. The entire wall of the trench must be protected either by sheeting set in place as soon as the excavation METHODS AND COST OF TRENCHING 847 I Fig. 25. Vertical Sheeting and Extensible Braces. 848 HANDBOOK OF EARTH EXCAVATION is completed, or by sheet piling which is driven ahead of the ex- cavation. Sheet piling is always driven vertically, but shei-ting may be placed either vertically or horixontally. Sheeting and sheet piling are of timber or steel. For timber, 2 in. should be the minimum thickness. Sheet piling of 2 x 8-in. stuff is usu- ally the most satisfactory. Sheeting should be placed in direct contact with the bank which should be trimmed to bear evenly against it. If sheet piling is driven ahead of the excavation, the safety of the trench is as- sured. Sheet piling has a better bearing against the bank than other forms of bracing, but its greatest point of superiority is that it can be driven below the depth of excavation where it helps cut off the flow of water and where the unexcavated material, holding it apart, takes the place of bracing. This gives the la- borers an unobstructed place to work in. Horizontal sheeting is not recommended except under obstruc- tions which make the use of vertical bracing impossible. Cost of Wood and Steel Sheeting. The cost of sheeting tranches depends upon several factors: (1) The nature of the ground; (2) the si/e of the trench; (3) the methods pursued in driving and pulling; (4) the kind of material used for sheeting (wheiiher wood or steel); (5) the type of braces used; (0) the difficulty experienced in driving; (7) the skill of the workmen; and (S) the speed with which the excavation proceeds. The following was published in Engineering Record, May 23. 1915. The work was the construction of narrow sewer, drain and water pipe trenches, 8 to 15 ft. deep, in soil of glacial origin. The nature of the ground varied from very sandy to fairly firm soil, and the amount of sheeting and bracing required varied ac- cordingly. Some bracing was used at all times. The sheeting used was either 2 x 8-in. lumber or Wemlinger corrugated steel piling, and the bracing was 3 x 9-in. lumber and Dunn extensible braces. At the beginning of the work, 400 pieces of Wemlinger steel piling, 10 ft. long, and about 5,000 ft. of 2 x 0-in. long-leaf yellow pine planking were purchased. The steel piling cost 28 ct. per sq. ft. and the lumber about $35 per M. At the end of one season the lumber had been used up, but the steel piling was in first class shape and was used during several successive seasons although subjected to hard usage for purposes other than trenching. In trenches averaging 9 ft. deep 3 men averaged 70 ft. of trench sheeted solid with wood per 10-hr, day. In firm sand the average was 100 ft., but in caving sand it was 30 ft. a day. The same gang removed the sheeting at the rate of 210 ft. of trench per METHODS AND COST OF TRENCHING 819 m 1 ] Fig. 26. Horizontal Sheeting and Extensible Trench Braces. 850 HANDBOOK OF EARTH EXCAVATION day. When the sheeting was not solid, but spaced 3 to 6 ft. apart, 3 men averaged 150 ft. of trench braced per day. Using steel sheeting 3 men averaged 60 ft. of trench (11 ft. deep) sheeted per day. In pulling this sheeting with a difl'er- ential block, 2 men averaged 45 ft. of trench per day, the trench being filled to a depth of 6 ft. before pulling. In some work in Peoria, 111., the engineer for the contractors kept close account and found that in trenches from 8 to 16 ft. deep in sand with 2x8 sheeting and 6x6 braces of hemlock, the sheeting cost in place and pulled after use, ready to use again, from 10 to 25 ct. per lin. ft. of trench. The excavating and back filling, including contractors' profit, cost from 21 ct. per ft. for trench less than 8 ft. deep to 76 ct. for trench 14 to 16 ft. deep. Cost of Driving Sheet Piles. In Municipal Engineering, Vol. xxi, p. 409, 1901, Emmett Steece says that the cost of driving sheet piles is subject to greater variation than round piles in soft soil and will vary from 5 to 12.5 ct. in trenches less than 10 ft. and from 25 to 75 ct. per ft. in trenches between 10 and 20 ft. in depth for pipe sewers, and increasing slightly with the size of pipe. For larger trenches the cost increases rapidly with the width and depth. A trench 25 ft. deep and 16 ft. wide costs about $2.75 per ft. to sheeting for driving and removing. The Cost of Driving by Pile Driver. Victor Windett gives the following in Engineering and Contracting, June 14, 1911. In alluvial soil 2 x 12 in., 14 ft. and 3 x 12 in., 24 ft. sheeting was driven by a 2,000-lb. drop-hammer pile-driver. No difficulty was experienced in sheeting 150 ft. of trench per day. The lum- ber was delivered along the line of the trench by teams. The pile-driver crew consisted of 9 men. The cost of preparation of plain ordinary trench sheeting is as follows : 467 pieces, 2x8 in., 12 ft. and 14 ft. trench sheeting, totaled 10,900 ft. B.M., and the labor cost of pointing and trimming the top was $2.60 per 1,000 ft. B.M., or 6 ct. per pile, labor being 27 ct. per hr. For steam-shovel work, as at Hegewisch in sand a light pile- driver was used with two hammers of 1,200 Ib. each (see Fig. 27). The sheeting used was triple lap. The center piece was 2 x 10 in. x 4 ft., with two 1 x 4-in. x 12-ft. side pieces, made up for a 2-in. tongue and groove. In a 9-hr, day 240 pieces of sheet- ing could be driven easily by the crew of 9 men, at a labor cost of 10 ct. per piece. The sheeting was pulled after the trench was partly backfilled, by a double drum, double cylinder engine on a platform some- METHODS AND COST OF TRENCHING 851 what similar to the pile-driver but substituting a hinged frame for the leads. A 3-in. chain and % in. cable were used for the lines. There were two lines, one for each side of the trench. This machine would pull sheeting for 100 ft. of trench in 2 hr. The crew consisted of an engineman, winchman, hooker-on and sheeting-catcher to land the sheeting on the bank within reach of a team. The wear and tear on the sheeting was very small, as far as Fig. 27. Sheet Pile-Driver with Double Leads for Trench Work the 2 x 10-in. pieces were concerned. They were used nine times and then made into bottoms for catch basins. The 1 x 4-in. strips required quite frequent renewal. Possibly it might have been cheaper to use 2-in. lumber instead. This sheeting was triple lap, middle piece, 2 by 12 in., 14 ft. long. Side pieces, 1 by 4 in., 10 ft. long. 732 pieces (34.5 ft. B. M. each). Labor making up (including pointing and heading to top width of 8 in.) at 31 ct. per hr., cost 9.3 ct. per piece or $2.60 per 1,000 ft. B. M. 852 HANDBOOK OF EARTH EXCAVATION The stringers used were generally 3x12 in. or 4x12 in. and 16 ft. in length of long leaf yellow pine. Braces were generally 6 x 6-in. yellow pine. In Gary, Ind., where the country was covered by a growth of various oaks, mainly small trees, many braces were cut from the standing tim- ber. These braces were usually 3 to 5 in. in diameter. Dunn trench screws are highly advantageous on account of ease of placing and removing the braces and of keeping them tight. Steel Sheeting at Watertown, N. Y. Engineering and Con- tracting, Nov. 15, 1911, gives the following: Wemlinger corrugated steel piling was used for sheeting sewer pipe trenches at Watertown, N. Y. The average cut was 15 ft. The soil was sand to a depth of 10 ft., and a wet sand and gravel beneath that point. Four hundred sheets of %-in. piling, each 1 ft. wide by 10 ft. long, were used. A 650-lb. steam hammer, furnished with power from a road roller, drove the piling. The trench was first excavated lo a depth of 5 ft. Three men then placed the piling upright at each side of the trench, the rate of placing being 32 sheets in 1.5 hr. These sheets were then driven to grade by the hammer hung from an A-frame, at the rate of 1 sheet driven 5 ft. in 35 sec. Including the time required for moving the hammer and A-frame, the rate of driving was 7 ft. of trench sheeted per hour. Spruce rangers, 4 x 6 in. xlGft. long were used. Braces were placed 7 ft. apart. Removing Sheeting. In pulling sheeting and sheet piles, vari- ous methods are used. The lower waling pieces are taken out as the trench is backfilled. Then after 50% or more of the back- filling is done the sheeting boards are drawn, although in some exceptional cases the sheeting is left in place. Chains, clamps Fig. 28. Device for Pulling Sheet Piles. METHODS AND COST OF TRENCHING 853 and grabs of various kinds, are used to pull the boards. Der- ricks and cableways are used as the power to pull them, although they are often pulled by hand. Fig. 28 shows a small tool used for pulling sheet piles. It can be used with a lever, operated by men, with a derrick or a cableway. It fits around the pile and as the pull is made it clamps itself to the board so that it seldom slips. If more than one pull is needed to take out the pile, the tool releases itself as soon as the pull is stopped and it slides down the board, taking a new hold the instant power is on it. Besides being simple in operation, this tool does not injure the boards, as do chains, clamps and grabs. A Machine for Pulling Sheet Piling. Engineering and Con- tracting, Dec. 6, 1911, gives the following: This pile puller, Fig. 29, is the invention of R. J. Blackburn and was used on the Glaise Creek sewer, Louisville, Ky. The top of the fall line of the derrick was attached to the top of the tripod while the closing line passed around the special blocks as shown. With this rig an average of 30 twenty -foot steel piles were pulled per hour. The labor force required consisted of three men and the derrick crew. In the construction of some sewers in St. Louis, Missouri, steel sheet piling was driven to a depth of 40 ft. and, after excavating nearly to quicksand, bulkheads of plank piling were built across the trench about every 20 ft. These bulkheads were 24 ft. high and were composed of timbers 8 in. thick. When the completed masonry of the sewer neared one of these bulkheads it was not feasible to pull the plank piling until the fill had been at least partly completed. The heavy cross timbers, in addition, were partly braced by the piling and had to be left in order to support the steel piling in the sides. Cutting off Piling with Pneumatic Augers. The following method is given in Engineering News, Aug. 6, 1914. The first attempt to cut off the piling was with an axe, but this method was -found to be extremely unsatisfactory. Large wood chisels fitted to pneumatic hammers were next tried without satisfactory results. A 1^4-in. wood boring auger operated by a " Little David " compressed air motor was tried, and found to be a prac- tical means for cutting these thick planks. About seven l^-in. holes were required to sever a pile, and the time consumed in bor- ing each of 'the holes 8 in. long was from 20 to 25 sec. The en- tire time consumed in making two cuts across the trench was be- tween 1.5 and 2 hr. Driving Wakefield Sheet Piling. The following is given in Engineering News, May 28, 1903. The construction of inter- cepting sewers for the purpose of diverting sewage into the 854 HANDBOOK OF EARTH EXCAVATION Chicago Drainage Canal was undertaken in 1901 by the city, em- ploying day labor, and having all work done under the super- vision of its own engineers. The following relates to work done on Section G, which ex- Fig. 29. Blackburn Pile Puller. Closing Line Pulling Up a 20-Ft. Pile. tended from 39th to 51st streets, and on Section H, between 51st and 63d streets. As this was the city's first experience in con- struction work on a large scale, it was necessary to secure an entirely new plant. Accordingly, the city built, with its own labor, a turntable drop-hammer pile driver, for use on Section METHODS AND COST OF TRENCHING 855 G. The driver had a hammer weighing 3,000 Tb., and was equipped with a 7 x 10-in. double-drum hoisting engine and a duplex steam pump for jetting. The machine cost $2,200. As the sewer for a distance of about 2,500 ft. would be under the shoal water of the lake, and for the rest of the distance very close to the water's edge, it was necessary to use sheeting, which would be practically water tight. Accordingly, Wakefield sheet piling was used, the lumber employed in its construction being 2x 12-in. x 12-ft., Norway and Georgia pine, surfaced one side and one edge. For most of the work Southern pine was used. In practice, however, it was found that Norway pine would stand 50% more blows under a drop hammer; and, in consequence, Norway sheet piling was used where there was difficult driving. About 12 ft. below city stratum the clay line was found. Im- mediately above this was a layer of fine blue sand mixed with shot clay. This stratum when loose and wet acts very much like quicksand. Above this stratum was ordinary lake sand. The sand was very solid and compact, owing to the action of the waves of the lake. But with the exception of gravel spots the seepage was small, considering the nearness to the lake. The first sheeting was driven nearly to the bottom of the proposed excava- tion; but later it was found that sheeting driven 4 to 5 ft. into the clay would do sufficiently well. In order to have the sheeting left to a sufficient height above the line of the lake for protection against high water, 20 ft. of material was used with some ex- ceptions. In the bracing, 10 x 12-in. x 22-ft. stringers and 10 x 10-in. x 20-ft. braces were used. Three sets of stringers and braces were found sufficient for most of the distance. In some places it was necessary, on account -of bad ground and swelling clay, to rein- force both stringers and braces. Throughout the entire work, 2-in. Dunn screw-braces were used. In construction, the top set of stringers and braces followed the scraping and leveling. The distance between the sheeting was 22 ft. for the 16-ft. conduit and 211/4 ft. for the 151/4-ft. con- duit. A clearance of about 9 in. between the sheeting and sewer brickwork was allowed. In the operation it was found practical to swing the pile driv- ing apparatus about once every day. Ordinarily about 50 ft. of sheeting in each direction was driven on one side, and then 50 ft. in each direction on the other side. A water jet for jetting 'the clay was used with marked success. Ordinarily, after jetting to the clay and getting the piling into position, four or five blows of the hammer were sufficient. In many cases isolated rocks, about \y 2 ft. in their largest dimensions, were found from 2 to 850 HANDBOOK OF EARTH EXCAVATION 8 ft. below the surface. These were disposed of by jetting a large hole beside them. The piles were held in place during driv- ing by a %-in. buck line, attached to the front drum of the hoist- ing engine, and leading through the sheaves attached to the pile driver and sheeting in place, to and around the pile to be driven. In making each Wakefield pile, 50-penny wire spikes were used. Half-inch carriage bolts were tried as fastings, but it was found that the carpenters could make at least twice the number of sheet piles when 50-penny wire spikes were used. Eight to ten spikes were used per pile. The pile-driving crew followed the gang setting the top braces. On straight work at least it was planned to have a distance of about 400 ft. between the pile driver and the excavating derrick, because when the driving was too near there was trouble with seepage water from the jet. In ordinary driving, the crew averaged about 90 pieces of sheet- ing per 8 hr. This is equivalent to 45 ft. of trench sheet piled. The largest day's work was 120 pieces of sheeting placed. On some days, however, when such obstructions as piers were en- countered, not more than 12 pieces of sheeting were driven; this occurred once perhaps in 300 to 400 ft. The pile driving crew consisted of the following: Per day 1 foreman $ 4.16 engineman 4.80 fireman 2.50 carpenters at $3.60 7.20 laborers at $2.50 10.00 jet man 3.00 ladder man 3.00 2 wench men at $3.00 6.00 Total labor cost per day $40.66 As about 45 ft. of trench was sheetpiled per 8 hr., the labor cost per linear foot of sewer amounted to 00 ct. The labor cost per pile was 45 ct. The bill of materials required for 00 ft. of piling (the avearage amount placed in an 8-hr, day) was as follows : 10.8 M. ft. B. M. 2xl2-in.x20 ft, timber at $22 $237.60 900 spikes, at $2.65 per 100 Ib 23 85 1 ton coal for pile driver 2.90 Total : $264.35 Adding the total labor cost of $40.66 and the total cost for material, etc., $264.35, we have $305 as the total cost of 90 ft. of piling, or 90 piles. From the above it will be seen that the cost per pile amounts to $3.38, of which $0.47 was for labor. The labor cost per 1,000 ft. B. M. of piling was about $3.90. Another pile driver was built by the city for the construction of the sheet piling in that section of the intercepting sewer between METHODS AND COST OF TRENCHING 857 51st and 73d streets, known as Section H. This machine was also constructed on a turntable and could be swung from one side of the trench to the other. In order to secure a good foundation bearing for the runways and rollers the span of the lower bed was made 34 ft. The driver was equipped with a 7 x 10-in. double- drum engine, had 40-ft. leads and a 2,500-lb. hammer. A jet pump, with water tank, 20 ft. jet tube and other appliances were among the equipment. As in the first case, the sheeting was of the ordinary Wake- field pattern, made up of 2 x 12-in. plank, fastened together, how- ever, by 60-penny spikes. The method of driving this sheeting was as follows: The top set of stringers and braces were put in place for 100 ft. to 200 ft. in advance, and about 18 in. below the surface of the street; a second set of stringers, parallel with the street, made up of 4 x 12-in. plank, was put in about 5 in. outside of the main stringers and on the same level as those in- side, for the purpose of keeping the sheeting in line. All braces and timbers were then covered with sand to prevent their being washed out by the water jet. The sheeting used was 18 ft., 20 ft., 22 ft. and 24 ft long, depending on the depth of the clay. The top of the sheeting was driven to about 1 ft. below the street grade, and the lower end was from 2 to 4 ft. in the clay. For each pile a hole was jetted to the clay line, and as soon as the jet tube was pulled out, a pile was dropped into place and pulled over the tongue of the previous pile. Excellent alignment was obtained by using a " buck line " to hold the sheeting in place while being driven. In this case the "buck line" consisted of an old cable having a loop at one end to go over th? head of the pile, the other end of the cable, after passing through a couple of snatch blocks, being attached to the hoisting engine. From 75 to 110 piles were driven in 8 hr., the number depend- ing somewhat on the character of the ground; 85 piles, however, were considered a fair day's work. The pile driving crew and wages were as follows per day: 1 foreman $4.16 1 jet man 3.50 2 ladder men 5.00 2 wench men '. 6.00 1 pileman 2.75 1 engineman 480 1 fireman 2.75 4 laborers 10.00 2 carpenters 8.40 Total labor per day $47.36 An average of 85 piles per day were driven, which is equivalent to about 42.5 ft. of trench piled. This was at the rate of $1.11 per ft. of trench for the labor cost. The labor cost per pile was 55 858 HANDBOOK OF EARTH EXCAVATION ct. The bill of material required for 85 ft. of piling was as fol- lows: 10.2 M. ft., 2-in. x 12-in. x 20 ft. timber at $25 $255.00 850 spikes, at $2.65 per 100 22.52 1 ton coal for pile driver 2.90 Total materials $280.42 From the above it will be seen that the total cost for material and driving was $3.85 for each pile, of which $0.55 was for labor. The labor cost for 1,000 ft. B. M. of piling was about $4.58. Trench in Muck Soil. In excavating the foundation of the Manchester Ship Canal grain elevators, through very soft soil, great difficulty was encountered. This work is described by G. G. Lynde in the Proceedings of the Institution of Civil Engineers, vol. 137 (1898-99). Ihe upper 14 to 18 ft. of the soil consisted of a black mud which had been deposited by previous dredging work. About this "sludge" red sand and small lumps of sand- stone had been spread to a depth of 1.5 to 2.5 ft. The ground underlying the sludge consisted of an alluvial deposit, a bed of blue silt, 4 ft. thick, being found at a depth of 18 ft. below the upper ground surface covering a bed of wet running sand, 3 ft. thick, which lay on coarse sand and gravel. The black mud had naturally the consistency of butter, and in this state was as impervious to water as clay puddle, but when mixed and stirred with water, -as in the bottom of the trenches, it became thin black mud. As the entire excavation was made by steam travel ing-cranes loading into cars hauled by locomotives, the weight of machinery caused a settlement of the ground in the immediate neighborhood and a corresponding rise in the bottoms of the trenches and else- where. A few of the trenches in fairly good ground were sunk by poling boards in the ordinary way, but in other trenches no prog- ress could be made, the bottom rising as fast as it was excavated and the timbering and surrounding ground sinking at the same time. Certain trenches 8.5 ft. wide and from 23 to 26.5 ft. deep were excavated by the following method. The sludge was 17 ft. deep with a somewhat, hardened crust, and it was decided to use a sheeting plank or runner 2.5 in. thick by 7 in. wide, sharpened to a chisel point, and driven with the bevelled side towards the trench, so that the tendency of this sheeting plank was to incline outwards. The depth of the trench would have required long and unwieldy sheeting plank had they been driven from the sur- face to the full depth, so an excavation was first made in the hardened crust and sheeting 6 ft. long was first placed. Two frames were set, each consisting of 2 walings of 9 x 3-in. timber METHODS AND COST OF TRENCHING 859 12 ft. long, with 3 struts 8 in. square capped with 1-in. boards as shown in Fig. 30. Runners 14 ft. long were driven inside these walings into the solid ground by a small hand-operated weight of 300 lb., as shown in Fig. 30. s. TOP FRAME IN RUNNERS PITCHED PLACE Fig. 30. Top Frame in Place and Runners Pitched. The excavation was then carried down with frames of 3 x 9-in. walings and 8-in. struts inserted every 2 ft. deep, as shown in Fig. 31. RUNNERS DRIVEN EXCAVATION REMOVED FRAMES IN PLACE Fig. 31. Runners Driven, and Excavation Removed Frames in Place. 8.SO HANDBOOK OF EARTH EXCAVATION Curious effects were met with during the excavation of these trenches. The bottoms of the trenches were continually rising and a corresponding fall in the level of the surrounding ground took place. The ground sank as much as 3 ft. under the traffic of the locomotives and cars. Thus the boards on the loaded side of the trench sank while the timber on the inner side generally re- tained its position, endangering the whole structure. The struts or braces were thus transformed into diagonals, and to counteract this motion opposite diagonals were inserted, as shown in Fig. 32 Fig.!). Scale. 1 inch = 12 feet. Fig. 32. Showing Trench Distorted by Settlement and with Counter Rakers. O'Rourke Method of Excavating Deep Cuts to Neat Lines. John F. O'Rourke has patented and used successfully on subway construction in Brooklyn, N. Y., the method shown in Fig. 33. Engineering and Contracting, June 7, 1916, gives the patent speci- fications. The general method of procedure is sufficiently clear without description. The Bottomley Trench Brace. Engineering and Contracting, Dec. 11, 1912, gives the following: An improved fitting for timber braces to be used in shoring up trenches in bad ground has just been put on the market by the Bottomley Machine Co. of Alliance, Ohio. Fig. 34 shows the fit- ting and the timber required in its utilization. This fitting renders unnecessary the use of solid 4 x 4-in., 6 x 6-in., and 8 x 8-in. timbers for braces. In using it two pieces METHODS AND COST OF TRENCHING 861 of 2 x 4-in., 2 x (5-in., or 2 x 8-in. timbers are sawed the same length. The fitting is then fastened to the pieces selected by means of lag screws. The brace so formed is made rigid by spik- Fig. 33. Typical Section Showing Method of Excavating Deep Cuts with Vertical Sides. ing two short pieces of the same scantling as the long pieces be- tween the latter. The small block at the end adjacent to the cast- ing may be set clear of the screw or hollowed out to box the screw r __^^_______^^___ =m EngtContg. Fig. 34. The Bottomley Trench Brace and Built-Up Timber. in. Similarly, if desired, instead of using the two small blocks the timber can be built in solid. In that case the. screw is boxed in. 862 HANDBOOK OF EARTH EXCAVATION This device enables the contractor to utilize old but solid tim- ber which has been used for other purposes on the work. This effects a considerable saving in cost of timber over buying solid stuff. Moreover the casting can be fitted to the 2-in. timber in much less time than that required to fit a cast head on a solid stick. The casting is made of malleable iron threaded so as to engage the screw. The screw is 1} in. in diameter and is threaded for a length of 14 in. The vice handle is 1 x 9 in. The lag screws required for fastening the casting to the timber are furnished with it. The Kalamazoo Extensible Trench Brace, mde by the Kala- mazoo Foundry and Machine Co. of Kalamazoo, Mich., is shown in Fig. 35. Fig. 35. Kalamazoo Extensible Trench Brace. Methods and Costs of Trench Pumping. The cost of removing water from trenches is sometimes very high. Nevertheless, no matter how expensive the removal of water may be, it is usually less than the added cost of excavation and pipe construction in partially unwatered trenches. It is almost impossible to get laborers to work efficiently in wet ground, and it is absolutely impossible to get masons to do a proper day's work under such conditions. There are three general methods of unwatering trenches : ( 1 ) By pumping the water directly from its location in the trench; (2) by leading it from the place where work is being carried on to a natural or artificial sump, by means of a drain ; and ( 3 ) by unwatering the site by " bleeding." Direct Pumping. Where the flow of water does not exceed 50 gal. per minute, one man with a diaphragm pump will keep the trench clear. Where the flow does not exceed 75 gal. per minute a two-man pump is required. Edson diaphragm pumps, with 20 ft. of hose and strainer, cost $48 for the one-man size and $70 for the two-man size. For flows of 60 to 80 gal. per minute, a dia- phragm pump operated by a gasoline engine is very efficient. It can be started in the morning and given little or no attention for the remainder of the day. For removing greater quantities of water centrifugal or recipro- cating pumps are generally used. Emmett Steece gives the pre- war cost of a centrifugal pump and its operation as follows: METHODS AND COST OF TRENCHING 863 Centrifugal pump with 5-in. suction $110 Timber framing 6 80-ft. of 9-in. belt 36 6-hp. gas engine 350 Total cost $502 This engine uses 5.5 gal. of gasoline per 10-hr, day. Pumping for Sewer Construction in New Orleans. Victor Windett gives the cost in 1911 of pumping with an 8-in. centri- fugal pump. The work was the construction of a sewer in New Orleans. The pump was in constant service for 417 days. While steam was kept at operating pressure continuously, the pumping was intermittent during each 24 hr. The inflow of water required pumping for a total of 12 hr. each day. The labor charge was low, the men being paid $73.50 each per month, or 20 ct. per hr. There was one man to each 12-hr, shift tending the boiler and pump. The daily cost of operation was as follows: Coal, 1.275 tons at $3 per ton $ 3.80 Oil for lubrication and illumination 0.25 Supplies 0.15 Water tax 0.33 Repairs to pump and boiler 0.93 Depreciation 0.75 Wages 4.80 Total i $11.01 Overhead burden 1.34 Total daily expense , $12.35 The Pulsometer Pump. This pump has been used for trench pumping for 50 years. This pump, while uneconomical in steam consumption, is reliable, and, once started, requires almost no attention. One advantage of this pump is that it can be hung anywhere in a trench and requires no foundation. It has no moving parts except valves and requires no lubrication. It is made in various sixes by the Pulsometer Steam Pump Co., New York City. A Tile Drain for Handling Water. Engineering and Contract- ing, Oct. 2, 1907, gives the following: In the construction of a 66-in. reinforced concrete sewer, the material encountered in excavation was loose black soil for a depth of 24 ft., and sand and gravel, water bearing for about 5 ft. at the bottom. The average depth of the trench was 18^ ft., with a width of 10i/ ft. To handle the water a subdrain, pump and sump were used. The pipe used for subdrain was second class and cull pipe, laid with the invert 30 in. below the invert of the main sewer. Joints were loosely calked with tufts of sod in order to hold back the fine sand, and the whole covered with clean gravel of medium size. The drain pipe emptied' into a sump 864 HANDBOOK OF EARTH EXCAVATION at the lower end of the new work, which was about 18 in. below the subdrain grade, in which was a 6-in. centrifugal pump, used to discharge the water over a dam in the old portion of the sewer. By this method it was possible to put the concrete on a dry bot- tom. It was found necessary, however, to run the pump while the invert was being plastered, and it was kept going until the plastering was set, otherwise the water would force its way in from the outside and cause the mortar to slough down, leaving the bottom rough and the sides, to some extent, porous. The total cost of caring for the water was as follows per foot of sewer: Subdrain pipe $0.33 Labor laying drain pipe 0.35 Handling water 0.45 Total per ft / $1.13 Cost per cu. yd. of excavation 0.115 The item handling water includes the fuel, housing and rental of pumping engine, pay of engineman, also sinking of two sump holes for the pump and filling up of same after the work was done. The engineman received $2 per 10-hr, day, and common labor received $1.85. Pumping- for Sewer at Harrisburg, Pa. Engineering Record, Oct. 15, 1904, gives the following: The main sewers comprised 7,600 ft. of reinforced concrete sec- tion 12.3 sq. ft. in area, and 7,670 ft., 10.3 sq. ft. in area. Trenches were 8 and 9 ft. wide, and averaged 10.5 ft. in depth. Most of the work lay alongside Paxton Creek which was in flood several times. An excessive amount of water was everywhere en- countered. To handle this an 8-in. underdrain was used almost the whole length of the work. It was laid with open joints, filled around with gravel, and connected with sumps at the side of the trench, from which the water was pumped. These sumps were about 6x6 ft. in size and were excavated at irregular intervals at the same time as the trench but 2 ft. deeper. At some places it was necessary to lay a double line .of 8-in. underdrain. Six-inch direct-connected Morris centrifugal pumps were used. One pump was used for each section of the work, the pump being moved ahead, when necessary. The average length of section pumped was 550 ft., and the maximum 1,750 ft. The ground water level varied considerably but averaged 6 ft. above subgrade. A typical section yielded about 2,200 gal. per lin. ft. per 24 hr. The cost of pumping on the main trench, including the cost of underdrain, was about 36 ct. per cu. yd. of excavation, or $1.30 per lin. ft. of trench. Coal cost $3.80 per ton. A fireman attended each boiler and a boy each pump, day and night. The material encountered was firm clay with occasional layers METHODS AND COST OF TRENCHING 865 of gravel, and covered with various kinds of top-soil. The greater part of the invert was laid on an underlying stratum of gravel. Very little solid rock was encountered. In the streets and on level, dry land, where possible, a Jackson hoist was used, and the material excavated was carried on cars and dumped on the completed work. In deep cuts where the con- dition of the surface did not permit the use of the Jackson hoist, buckets and boom derricks were used. In shallow cuts excavation was done entirely by hand. The total excavation of the main line amounted to 54,465 cu. yd., and cost 71 ct. per cu. yd. About 38,587 cu. yd. were backfilled at a cost of 38 ct. per cu. yd. Com- mon labor was paid 15 ct. per hr. Tight sheeting, placed vertically, was generally required, but in shallow cuts, skeleton sheeting was used. Two-inch lumber was used. The rangers and cross braces were of wood. The sheet- ing cost about 87 ct. per lin. ft. of trench. TJnwatering by Use of " Bleeding Points." Otto Gersbach in Engineering and Contracting, June 5, 1907, gives a description of a method used at Indiana Harbor, Indiana, for drying out water bearing sand. This method is now frequently used in wet material and is commonly known as the method of " bleeding by points." At Indiana Harbor, pipe sewers of 8 to 30-in. diameter were -laid in sand to depths as great as 21 ft. After excavation had proceeded until ground water was reached, 2-in. iron pipes, 10 ft. long were driven down by the aid of a water jet operating at a pressure of 25 Ib. per sq. in. These pipes were pointed, and were perforated just above the points, the perforations being covered with a fine wire netting in order to exclude the sand. The pipes were spaced 4 ft. apart as a rule, but 8 ft. in some cases. They were driven to a point below the grade of the sewer, sections 2 to 4 ft. long being used to lengthen the standard 10-ft. section where necessary. The pipes were driven in lines close to each side of the trench. The driven pipes were connected by short lengths of hose to a 4-in. main pipe running lengthwise over the center of the trench and supported by plank. The 4-in. pipe was connected to a 10x6xl2-in. duplex pump run by a 20-hp. boiler. Thus the trench was kept dry. Little or no sheeting was required as the damp sand did not run. A row of planking was placed at the top of the trench to keep back sand that might be pushed down by the men above. Excavating Quicksand in Toronto. The methods used in ex- cavating, sheeting and pumping trenches for 20 and 24-in. pipe sewers at North Toronto, Canada, are described by George Pkelps, 806 HANDBOOK OF EARTH EXCAVATION in Engineering and Contracting, Dec. 25, 1912. Most of the trench was 30 ft. deep, and the nature of the material (quicksand and water at depths of 16 ft.) made the work very difficult and ex- pensive. Further disadvantages were ( 1 ) the narrow working space which prevented the use of conveying and backfilling ma- chines, (2) the great depth of cut, and (3) the cold weather. The material was removed from the trench by hand in stages. When the excavated material was allowed to lie for some time it froze, and backfilling was necessarily expensive. Frost wedges and dynamite were used to break up some of the material. The system of cross braces shown in Fig. 36 was adopted to prevent the collapse of the curbing. Extra diagonal braces were often put in as well, but even this did not ahv r ays prevent the set- tling of the timber work with the falling sides. The timbering consisted of two settings of 2 x 6-in. pine runners, the top set- ting being 12 ft. deep and the bottom 16 ft. deep. The wa lings and struts were of 4 x 6-in. pine, and the cross braces of 2 x 6-in. pine. A uniform width of trench was kept and each setting of timber was 16 ft. in length, this being the length of walings used. The walings were about 4 ft. apart vertically, three on each side for a top setting and four for a bottom setting. The cross braces and 4 x 6-in. struts were placed at each end of the walings in ad- dition to 4 x 6-in. struts in the middle, the timbering thus being divided up into 8 ft. bays. After the bottom setting of timber had been driven down to the full depth, the joints of the runners were covered with short lengths of 1-in. boards to keep back the sand as much as possible. This helped considerably but did not entirely prevent the sand from washing in. The drawing of the timbers after the pipes had been laid was attended with some danger. The bottom setting was first drawn, often exposing big caves in the sides of the trench where the ma- terial had washed away. These, with the trench, were filled up to the bottom of the next setting before any of the top timbers were disturbed. On removing the struts from the top setting the sides of the trench often fell in from several feet back, to the great danger of the timbermen, but fortunately the work was completed without any serious mishap from this cause. In passing the telephone poles which came immediately on the side of the trench, the top setting of timber was left in for safety. In addition stays were placed on the poles and left there after completion of the work to protect them from heeling over or sinking until the trench settled down quite firm. In some places where the ground was very bad, particularly at a point where the trench passed close to a grove of trees, the whole of the timbering was left in the trench. After filling such places a large amount METHODS AND COST OF TRENCHING 807 of surplus earth remained to be hauled away. The trenches have shown very little sign of settling down since being filled, and it is likely that the caves left behind the timbering where it was not drawn will silt up from underneath quicker than the filling ma- terial will find its way through from above. Pumping was required at all times. At the beginning of the 16-0 ii '6 Braces n Fig. 36. Longitudinal and Transverse Sections of a Top and Bottom Setting of Timber for 30-Ft. Sewer Trench in Quick- sand. bad stretch a sump was located and the water was removed from this by a Pulsometer pump. In capacity it was found to be more than sufficient to deal with the quantity of water, and there- fore it was worked intermittently. For this reason the sand that was carried by the water settled down on the valves during the periods of rest and there was often a delay in getting the pump to start again. 68 HANDBOOK OF EARTH EXCAVATION Shortly after the commencement of the work on the flat grade it was found impossible to keep -the sewer free from the sand carried in suspension in the water, and being very fine, it quickly settled down in the pipes and formed an obstruction. Attempts were made by means of rods and chains drawn through to keep the pipes clear. Flushing from a hydrant also was tried. But the level of the water could not be kept down sufficiently to make good joints, and pumping in front of the pipe layers had to be resorted to. A 4-hp. vertical gasoline engine and a belt-driven centrifugal pump were provided for this purpose. The pump was set down in the trench about 10 ft. above the invert of the sewer. About 35 ft. of flexible suction hose was attached to the pump, making it possible to lay about 70 ft. of pipe before moving the pump further along the trench. The gasoline engine occasionally gave a little trouble, but the centrifugal pump proved quite satis- factory for dealing with the very sandy water, which was raised to the surface and discharged on the other side of the road. The sand flowed so freely into the trench that often, after stand- ing over the week-end, it had filled the trench up to the level of the top of the pipes. The bottom of the trench was good, as a rule. The quicksand came from a few feet higher up. In some places, however, where the' bottom was soft, timbers were put in to give a firm bearing for the pipes. As a result of the flow of sand into the trench, caves were formed behind the sheeting. When a delay occurred which caused the trench to be left open a little longer than usual, big falls of sand took place, due to the cave and the weight of earth above. These falls often pulled down the top setting of timber a few feet, causing the walings to snap. This constituted a great danger and the work was delayed on several occasions by the caving in of the sides of the trench from this cause. Building a Brick Sewer in Quicksand. Curtis Hill gives the following in the Transactions of the Cornell Society of Civil Engi- neers (1905). In St. Louis an oval-shaped sewer, 4x6 ft. in size, was constructed on a quicksand bed, the three lowest feet being in quicksand. The trench was excavated until quicksand was found when sheeting was driven first along the sides and then across the line of sewer to below subgrade, thus boxing off a section of quicksand. This was excavated as rapidly as possible, and burlap sacks, loosely filled with dry concrete, were placed in the bottom of the trench immediately and tamped into the sand. These sacks were placed slightly lapping one another, the outside ones resting upon the sheeting at the sides, and roughly conformed to the shape of the sewer invert. Nine or ten inches METHODS AND COST Of TRENCHING SCO of concrete gave a stable foundation and the brickwork was built directly upon it. Solidifying Quicksand by Injecting Cement Grout. At Provi- dence, R. I., according to Engineering Neics, Apr. 28, 1892, great trouble was experienced in 1891 in the construction of a large sewer in quicksand. The contractors were unable to proceed, and petitioned for cancellation of their contract, which petition was granted by the cjty council. In the vicinity of the sewer a large section of wooded area about 150 x 75 ft. in extent sank several feet after a pump had been operating in the trench for 2 days. The trench had to be from 12 to 15 ft. wide and 20 to 30 ft. deep in quicksandy ma- terial saturated with water almost to the surface. The force of the flow of quicksand was almost irresistible, 4-in. splined spruce sheeting in a 30-ft. trench snapped off several planks at a time, and spruce struts were forced into the rangers. An experiment was made with an invention of Robert L. Har- ris. Four pipes, 4 ft. apart, were driven to a depth of 17 ft. Water, forced down two of the pipes, washed out a chamber while seeking an outlet through the other pipes. A smaller pipe, with suitable valves, was then put do^vn inside one of the larger pipes. When this small pipe extended below the outside of the larger pipe there was a free passage for fluid up or down. When the inner pipe was drawn up a little, it acted as a valve and closed the larger pipe. Cement grout, " doctored " with sand and plas- ter of Paris, was then forced down the smaller pipe. By repeat- ing this a floor of concrete was formed. Freezing Quicksand. Maurice Deutsch, in Engineering News, Jan. 30, 1913, describes the successful employment of the freez- ing process in the excavation of a building foundation in Berlin, Germany, where ordinary methods had previously proved a failure and had caused settlement of adjoining buildings. The material was quicksand, extending to considerable depth. The cellar ex- cavation was carried a distance of 36 ft. belew ground water level and 25 ft. below the foundations of the adjoining buildings. Closed pipes, on 3-ft. centers, 5 in. in diameter and % 6 in. thick, were driven vertically 59 ft. deep, around the site, 6.5 ft. from adjoining buildings. Inside these pipes was set a l-in. brine pipe. Refrigerating brine was pumped down the l-in. pipe and up the annular space between that pipe and the surrounding 5-in. pipe, at a velocity of 11.5 ft. per min. After four weeks, the ground was frozen sufficiently for excavation which was ac- complished by dredging. The bottom of the excavation was cov- ered with a thick bed of concrete placed under water. 870 HANDBOOK OF EARTH EXCAVATION Bleeding Wet Sand at Gary, Ind. Engineering and Contract- ing, Aug. 5 and Oct. 14, 1908, gives the following, The sand at Gary, Ind., is very fine, and is such a sand as forms the dunes of Michigan and other states bordering Lake Michi- gan. When water soaked it slopes at a grade of 1 vertical to 15 horizontal. On the location of the work this fine sand was water soaked to within a few feet of the surface. In places the water covered the surface. In constructing a brick sewer of oval section, 6 ft. 4 in. by 8 ft. 11 in. in size, the trench was dug to depths varying between 18 and 30 ft. A preliminary wide shallow cut was excavated first by a grab bucket and later by scraper bucket. For the first 1,900 ft. a %-cu. yd. Hayward orange-peel bucket, operated by a 25-hp. engine, was used. This machine removed 21,250 cu. yd. at the following cost. Engineman, 56 days, at $6 $ 336.00 Fireman, 56 days, at $3.50 196.00 Laborers, 255 days, at $1.75 446.25 Coal, 56 shifts, at $5 280.00 Total .............................................. $1,258.25 Cost per cu. yd ................................... $0.059 At this point the orange-peel was removed to the rear to work on backfilling and a Page & Schnable drag scraper excavator was substituted. This machine had a 2-cu. yd. bucket and a 40-hp. engine. This engine was found to be too weak and was used only until a larger one could be secured. Another objection to the first arrangement was that two men were required to operate the bucket, one at the hoist and one at the swing engine. With the machine as first equipped and operated 15,300 cu. yd. of material were excavated at the following cost: Engineman, 31 days, at $6 ............................. $186.00 Fireman, 31 days, at $3.50 ............................. 108.50 Engineer, 31 days, at $3 ......... ...................... 93.00 Laborers, 118 days, at $1.75 ............................ 206.50 Coal, 31 shifts, at $5 ................................... 155.00 Total ................................................ $749.00 Cost per cu. yd ..................................... $0.049 The 40-hp. engine was replaced by one of 60-hp., so arranged that one man operated both hoist and swinging engine. With the remodeled outfit 11,000 cu. yd. of material were excavated at the following cost: Engineman, 21 days, at $6 .. ....[^^Y.. ..' $126.00 Fireman, 21 days, at $3.50 ............................. 73.50 Laborers, 84 days, at $1.75 ............................. 147.00 Coal, 21 shifts, at $5 ........ '...'..::.. . ..... . ........... 105.00 Total ............... ............ "....:.':.!;'-V.'.'!:.. $451.50 Cost per cu. yd ..................................... $0.041 METHODS AND COST OF TRENCHING 871 It will be seen that the change of engines reduced the cost per cubic yard by the amount of the wages of one engineman; the saving was 0.83 ct. per cu. yd. Summarizing we have a cost of $2,488 for excavating 47,550 cu. yd., or of 5.23 ct. per cu. yd. For the 4,258 ft. of sewer the cost was 57.9 ct. per lin. ft. The machine was mounted on rollers traveling on a track of timbers. One merit of the machine was that some of the excavated material could be dumped straight ahead in the path of the work so that it built its own roadbed over the swamps in front. The machine was pulled ahead by simply lowering the bucket and letting it get a good bite in the ground ahead, then pulling on the digging cable. When the scraper bucket had excavated to water level the ground water was partially removed by the method known as " bleeding." This method proved eminently successful. It en- abled sand that normally flow's at a slope of 1 on 15 to be ex- cavated in narrow trenches to some 22 ft. below water level with only ordinary rough sheeting reaching to a point 6 ft. above the bottom. So important a factor in the successful prosecu- tion of the work was the " bleeding " that, according to one of the engineers on the work, had the pumping been stopped for half an hour the trench would have been dangerous to work in. The method of bleeding was essentially as follows: A 4-in. pipe, 132 ft. long, in six 22-ft. sections, stretched along the center line of the sewer. On each side of this pipe, about 3 ft. away, is sunk a row of well points 2 ft. apart. These well points are 3 ft. long and are attached to 13-ft. pipes. The tops of the driven pipes are connected by hose to the 4-in. pipe line which has cross- valves for the purposes. A pump connects with the 4-in. pipe line and also with a 4-in. well point sunk vertically underneath. An extension of the 4-in. pipe line with strainer end also takes the surface water from a sump. This battery of well points lowers the water so that a further excavation of 6 to 8 ft. can be made between sheet piling. A second battery of well points is then sunk at this new level. In this battery, however, the points are sunk close to the sheeting, and each row feeds into a separate 2-in. pipe along the trench. This battery lowers the water level enough to permit excavation to sub-grade, which is some 6 ft. below the bottom of the sheeting. The brick sewer is then built in the usual manner and the back- filling is done by means of a derrick and Hay ward clam-shell bucket. Fig. 37 shows the general plan of procedure described. It was noted that the vacuum type of pump seemed to be particularly 872 HANDBOOK OF EARTH EXCAVATION successful owing to its ability to work with a large amount of air in the suction and to its ability to handle gritty water. Referring to Fig. 37 it will be seen that the first battery of well points occupies a narrow space along the center of the trench; this permits the sheeting to be driven outside of the I I nimiiiiiiin Fig. 37. Scraper Excavator on Trench Work. well points. The well points are 2 in. x 3 ft., and they are at- tached to 2-in. x 13-ft. pipes with ells at their tops. A 4-ft. length of wire-lined hose is attached to each ell. These points are sunk vertically by jetting. Points of similar type but of less diameter that were used on a narrow trench are illustrated in Fig. 38. Fig. 38. Pump Point for " Bleeding. METHODS AND COST OF TRENCHING 873 Two men were timed in jetting. They used 1-in. jetting pipes with about 100 Ib. water pressure and sunk four points in one minute. This time did not include making connections. In addi- tion to the two rows of 2-in. points, a 4-in. point is sunk directly under the pump. The well points are connected by the short hose lengths to a 4-in. horizontal suction pipe. Six 22-ft. sections of suction pipe are used with flanged joints. Each section has 11 cross-valves with double bushings for the hose connections. A gate valve near the end of each section permits the rear-sections to be removed arid placed ahead as fast as the work progresses. An extension of the 4-in. suction pipe forward to a sump in the excavation be- ing made by the scraper bucket handles the surface water. r lhe water is drawn from the suction pipe by an Emerson No. 3 pump with 5-in. suction and 4-in. discharge. r lhe pump is hung to a chain fall from an A-frame mounted on rollers. It discharges into a tile drain alongside the trench; this drain leads back to the completed sewer discharging behind a temporary dam of bags of sand inside the sewer. Summarized, the first battery of well points is composed as follows: One No. 3 Emerson pump; 1 (4-in.) well point sunk below pump; 132 (2-in.) well points sunk in two rows; 1 (4-in.) suc- tion pipe with extension to surface water sump. The trench Was sheeted 10 ft. wide, the sheeting being carried along so as to embrace about one section (the rearmost) of the first battery of well points. The sheeting was 2 x 8-in. x 12-ft. planks and is driven by mauls. Waling pieces and trench braces were placed as the excavation proceeded. This excavation was carried down about 6 ft. by shovelers, and at this level the second battery of well points was placed. The sheeting was pulled as the back- filling proceeded. The second battery of well points consisted of two rows like the first, but the rows were placed wide apart (close inside the sheet- ing on both sides) and each had a separate suction pipe. The suc- tion pipes were 2 in. and the well points 1}4 in - i n diameter. The well points and pipes were 10 ft. long, and when sunk they pen- etrated about 2 ft. below sub-grade and 6 ft. below the bottom of the sheeting. Two pumps similar to those used for the first set of points op- erated this battery. Each drew water from both rows of well- points and also from a 4-in. well point sunk directly under thn pump. From a 4-way connection, 2-in. pipes branched right and left to connections with the 2-in. suction pipes. A third connec- tion was made to the 4-in. point. The pumps could concentrate their work on one portion of the battery or could pump from the 874 HANDBOOK OF EARTH EXCAVATION entire system. The pumps discharged into the same drain as the first pump. The methods of advancing the second battery wen- substantially the same as for the first set of well points. Gen- erally the forward end of the second battery was kept far enough ahead to overlap the rear section of the first battery. The pumping was continuous day and night, but the jetting of well points and changing of piping was confined to the regular shift of 9 hr. In this method of pumping it is important to keep lowering the points as the excavation deepens. If the points are driven to bottom grade at the beginning of the excavation work, an unnecessarily large amount of material must be unwatered. The item of pumping comprises all the work of sinking and shifting the well points and pipe line and the removal of the backwater in the finished part of the sewer. Three Emerson pumps took water from the well points, a fourth handled the backwater and a duplex pump furnished water for boilers, mixing mortar, jetting, etc. The cost was as follows: Laborers, 542 days, at $1.75 $ 948.50 Pipe line men, 958 days, at $2.50 2,395.00 Total for pipe work $3,343.50 Coal, 100 days, at $15 $1,500.00 Firemen, 855 days, at $3.50 2,992.50 Total for pumping $1,492.50 Grand total $7,836.00 Cost per lin. ft $1.837 Pumping eosts and pipe line costs have been separated, since the first in a continuous expense which does not vary from day to day, and the second cost is operative only when construction is actually going on. Hand Excavation. The bottom 13 ft. in depth of the trench was excavated by hand between sheeting; the width of the excavation was approximately 10 ft. The cost of the work was as follows: Laborers, 6,441 days, at $2 $12,882.50 Foreman, 84 days, at $3 J 522.00 Total $13,434.00 Cost per cu. yd $0.565 The total amount of hand excavation was 23,800 cu. yd. Sheeting. The sheeting consisted of vertical 2 x 8-in. by 12-ft. planks held by two pairs of 6 x 8-in. waling pieces and !)-ft. cross braces spaced 8 ft. apart. In cases of very wet trench a third row of waling and braces was put in; occasionally, also, hori- zontal sheeting was used in the bottom. Sheeting was driven to within 6 ft. of the trench bottom. The cost of driving the sheet- METHODS AND COST OF TRENCHING 875 ing and placing the bracing and also of pulling it was as fol- lows: Placing : Laborers, 882 days, at $2 $1,764 Foreman, 80 days, at $3.50 280 Carpenters, 50 days, at $3 150 Total $2,194 Pulling : Laborers, 242 days, at $2 484 Total $2,678 Cost per lin. ft $0.629 The materials were hauled 1,500 ft. in steel dump cars running on portable track; the cars were pushed by hand. Coal, lumber, supplies, etc., purchased from local dealers, were hauled by team. The cost of hauling was as follows : Laborers, 1,219 days, at $2 $2,438 ! oreman, 80 days, at $3.50 280 Teams and drivers, 180 days, at $5.50 990 Total $3,708 Cost per lin. ft $0.87 The construction of the 4,258 ft. brick sewer was as follows: Laborers, 1,506 days, at $2 $ 3,012.00 Carpenters, 50 days, at $3 150.00 Form setters, 225 days, at $3.75 843.75 Bricklavers, 471 days, at $10 4,710.00 Scaffold men, 236 days, at -$2.75 649.00 Brick tenders, 236 days, at $3.75 8S5.0u Mortar mixers, 387 days, at $2.25 860.75 Total - $11,110.50 Cost per lin. ft ' $2.609 As noted further on, the cost of brick and cement for the job was $14,436.50, or $2.384 per foot of sewer, making the total cost for labor and material $4.093 per lin. ft. Since there were 520 bricks per lin. ft. of sewer, the cost per cubic yard of the brick- work was approximately the same as the cost per lineal foot. The bricklayers averaged 4,710 bricks per man per 9-hr. day. Two barrels of cement were used per 1,000 bricks. Enough backfiUing was done by hand to cover the sewer and to permit the sheeting to be pulled; the remainder was done with the clam-shell excavator first used for preliminary trenching. The cost of backfilling by hand was as follows: Per lin. ft. Laborers, 378 days, at $2 $0.18 876 HANDBOOK OF EARTH EXCAVATION The cost of backfilling by machine was as follows: ;] ''- Laborers, 307 days, at $1.75 $ 537.25 Engineers, 93 days, at $6 558.00 Firemen, 93 days, at $3.50 325.50 Coal, 93 shifts, at $5 465.00 Total $1,885.75 Cost per lin. ft $0.440 The cost of the materials used in the job was as follows: 2,221,000 brick, at $5 $11,105.00 Utica cement, 6,663 sacks, at 20 ct 1,332.60 Universal cement. 6,663 sacks, at 30 ct 1,998.90 30 M. ft. B. M. lumber, at $20 600.00 Total $15,036.50 Cost per lin. ft $3.529 The costs of superintendence and general expenses were as fol- lows: Superintendence : Superintendent, 4 mo., at $150 $ 600 General foreman, 4 mo., at $125 500 Master mechanic, 4 mo., at $200 800 Timekeeper, 3 mo., at $60 180 Team, 100 days, at $4 400 Total $2,480 General Expenses: Waterboys, 220 days, at $1.50 $ 330 Clearing right of way, 60 days at $150 90 Total $ 420 Cost per lin. ft $0.099 Summarizing we have the cost per lineal foot of sewer as fol- lows: Excavation by machine $0.58 Excavation by hand 3.15 Sheeting 0.63 Hauling brick and other materials 0.87 Pumping 1.84 Laying brick sewer 2.61 Backfilling by hand ' 0.18 Backfilling by machine 0.44 Materials 3.53 Superintendence and general 0.68 Depreciation, repairs, setting up machines 1.50 Making 3 railway crossings $2,500) 0.58 Total per ft fc $16-59 sii ; '-.*}({ p !H {i i in T.. - The work was begun on April 2 and was completed on Aug. 5, 1908, during which time only 11 days were lost by the brick- layers. Cost of a Sewer in Quicksand at Gary, Ind. The following is given in Engineering and Contracting, Jan. 27, 1909; METHODS AND COST OF TRENCHING 877 A 66-in. brick sewer was constructed at Gary, Ind., by methods similar to those used for constructing an oval sewer described above. The land consisted of alternating ridges and marshes dif- fering in elevation about 10 ft. The trench, therefore, varied in depth from 14 to 24 ft., averaging 17 ft. The material was a fine sand saturated with water to a height of 13 or 14 ft. above the trench bottom. ,'i Construction was begun Aug. 1 and finished Oct. 1, 1908. La- borers on excavation, sheeting, pumping, etc., worked a 10-hr, day; tenders, cement mixers and helpers to bricklayers worked a 0-hr, day; bricklayers worked an 8-hr, day; firemen on pumps worked in 12-hr, shifts, and excavating machine crews worked a 9-hr. day. The costs of the various items of the work were as follows. Drag Bucket Excavator Work. The preliminary cut was about 30 ft. wide and from 4 to 10 ft. deep; there were 33,350 cu. yd. of excavation for the 4,062 ft. of sewer or about 8.21 cu. yd. per lin. ft. The excavator worked 83.5 shifts and so averaged nearly 400 cu. ft. per shift of 9 hr. The cost of operating the excavator was as follows: 1 engineman, at $6 $ 6.00 1 fireman, at $3.50 .' 3.50 4 laborers, at $2 8.00 Coal (estimated) 5.00 Oil, repairs, etc 2.00 Total per 9 hr $24.50 This gives a cost of 6.1 ct. per cu. yd. of excavation and of 50.3 ct. per lin. ft. of sewer. Excavation by Hand. The excavation between sheeting, approx- imately 8i/ x 10 ft., was done by hand, scaffolding the material from 3 to 5 times and an average of 4 times. The cost of the work was as follows: Foreman, 51 days, at $3.25 $ 165.75 Laborers, 2,184 days, at $2.25 4,914.00 Total $5,079.75 This gives a cost of 39.4 ct. per cu. yd., and of $1.25 per lin. ft. of sewer. Pumping. The pumping plant consisted of 3 No. 3 Emerson pumps drawing from the well points; 1 No. 2 Emerson pump tak- ing water from the pools formed behind the drag bucket ex- cavator; 1 duplex pump for boiler feed, jetting points, wetting brick, etc., and 4 30-hp. horizontal boilers mounted on wheels. This plant worked continuously. The cost of operation was as fol- lows : 878 HANDBOOK OF EARTH EXCAVATION Laborers, 464 days, at $2 $ Fireman, 439 days, at $3.50 - 1,536.50 Pipe linemen, 1,238 days, at $2.50 3,09400 Foreman, 27 days, at $3.50 94.50 Coal, 60 days, at $15 (estimated) 900.00 Total $6,553.00 This gives a cost per lineal foot of sewer of $1.01 for pump- ing. Charged entirely against the excavation between sheeting which was closely 12,893 cu. yd., the cost of pumping per cubic yard of excavation was 50.8 ct. Sheeting. The sheeting consisted of 2 x 8-in. x 12-ft. plank driven close on each side of the trench. This sheeting was braced apart by two 6 x 8-in. waling pieces set 3 ft. apart ver- tically and G x 8-in. x 8^-ft. cross-braces spaced 8 ft. apart along trench. The cost for sinking, bracing, pulling and bringing for- ward was as follows: Labor, placing and driving, 392 days at $2.25 $ 882.00 Labor, pulling and bringing ahead, 182 days, at $2.25 409.50 Foreman, 27 days, at $3 50 94.50 Carpenter, 36 days, at $3 108.00 Total $1,494.00 This gives a cost for sheeting of 36.8 ct. per lin. ft. of trench and of 11.6 ct. per cu. yd. of excavation between sheeting. There were about 73 ft. B. M. of sheeting and bracing per lineal foot of trench, so that the cost per M. ft. B. M. was practically $5 for labor placing, pulling, etc. Laying Brick Rewer. The sewer was built of two rings of brick. The invert was built in 24-ft. sections. Wooden centers with lag- ging 16 ft. long were used in laying the arch and 2 men knocked the centers down, brought them forward and re-erected them as fast as 6 bricklayers could work. The cost of laying was as fol- lows : Bricklayers, 223 days, at $10 $2,230.00 Tenders, 112 days, at $3.75 420.00 Scaffoldmen, 111 days, at $2.75 305.25 Mortar mixers, 225 days, at $2.50 562.50 Form setters, 100 days, at $3.75 375.00 Laborers, 715 days, at $2 1,430.00 Carpenter, 18 days, at $3 54.00 Total $5,376.75 This gives a cost of $1.32 per lin. ft. of sewer and of $5.28 per 1,000 bricks laid. Backfilling. The backfilling to a height of 2 ft. above the brick- work was done by hand, and for the remainder of the height by a 1-cu. yd. Hay ward clam-shell excavator. The backfilling by hand METHODS AND COST OF TRENCHING 879 called for 277 days' labor at $2 and cost, therefore, $554 or 13.0 ct. per lin. ft. of sewer. The cost of the clam-shell excavator work was as follows : 1 engineer, at $6 T 6.00 1 fireman, at $3 3.00 3 laborers, at $2 6.00 Coal (estimated) 5.00 Oil, repairs, etc 2.00 Total per day $22.00 There were 55 shifts worked giving a total cost of $1,210. In addition the drag bucket excavator was worked backfilling for 18 shifts at $24.50, making a total of $441. Lumping the work of both machines, the cost of backfilling was 40.6 ct. per lin. ft. of sewer and 6.8 ct. per cu. yd. Materials. The cost of materials was as follows: 1,018,000 brick, at $5 per M $5,090.00 3,054 bags Utica cement, at 20 ct 610.80 3,054 bags Universal cement, at 35 ct 1,065.90 Lumber (estimated) 600.00 Total $7,369.70 This is a cost of $1.81 per lin. ft. of sewer. Hauling Materials. For about 3,000 ft. of the work all ma- terials were hauled from the railway siding in 2-cu. yd. steel dump cars running on narrow gage track. The average haul was 1,700 ft. For the remainder of the work the hauling was done with teams; brick were hauled by subcontract for 70 ct. per M. Two teams were also employed throughout the work to haul supplies from local dealers and to haul coal to the excavators when they were beyond reach of the contractors' railway. The cost of haul- ing was as follows : Laborers, 767 days, at $2 $1,534.00 Foreman. 52 days, at $3.50 182.00 Brick, hauled by team at 70 ct. per M . . 194.60 Teams, 100 days, at $5.50 550.00 Total $2,460.00 The cost of hauling was thus 60.7 ct. per lin. ft. of sewer. Superintendence and (teneral Expenses. The costs under these items comprised the following: Superintendent, 2 months, at $150 $ 300.00 General foreman, 2 months, at $150 300.00 Master mechanic. 1 month, at $200 200.00 Clearing right of way 80.00 Waterboys, 160 days," at $1.50 240.00 Handy teams, 52 days, at $3 156.00 Total $1,226.00 880 HANDBOOK OF EARTH EXCAVATION This gives a cost of 30 ct. per lin. ft. of sewer. Summary. Summarizing the costs of the work per lineal foot of sewer we have: Drag bucket excavation $0.503 Hand excavation 1.250 Pumping 1.610 Sheeting 0.368 Laying sewer 1.320 Backfilling by hand 0.136 Backfilling by machine 0.406 Materials 1.810 Hauling materials 0.607 Superintendence and general 0.300 Depreciation of plant, repairs, etc. (estimated) 1.500 Total per ft $9.810 Draining Quicksand by "Bleeding." Frank I. Barrett, in En- gineering News, Sept. 25, 1913, describes a method used for car- rying a 22 x 40-ft. opening through an 8-ft. bed of quicksand 35 ft. below a river bottom. The quicksand was so soft that a man could not stand on it, and water boiled up under sheeting that had been driven 12 ft. below the top of the sand. The method successfully used was to fasten at the inner side of the sheeting, 19 ft. above grade, a 6-in. pipe header, with T-joints and valves spaced 3 to 5 ft. apart. To these Ts were connected 2-in. pipes with 60-mesh well points, 3 to 4 ft. long, driven 6 in. below grade. The water was removed from the header pipe by a G-in. duplex pump. A second pump, with a large supply of spare valves, stems, etc., was kept in reserve. The pit was dry af H- 9 hr. of pumping and was excavated in 12 hr. Pumping Quicksand from a Trench. A description of the methods and costs of constructing pipe sewers in quicksand at Wildwood, N. J., is contained in Engineering and Contracting, June 3, 1908. The land originally was covered at high tide by 3 ft. of water, but had been filled in above high tide level by dredged material. The original soil was black mud covered with thick meadow sod, with, here and there, piles of sand which were shifted by the tide. The trench for the entire distance, 12 miles, was through quicksand, from which water bubbled, and known locally as " boiling sand." This made both expensive and difficult work, adding to the cost of laying the pipe, as it was difficult to keep the pipes at the proper grade and in good alignment, and the joints were hard to caulk, owing to the water in the ditch. The greatest cutting was 6} ft. deep and the entire trench was double sheeted throughout, great trouble being experienced in keeping the trench even partially dry. Sumps or wells could not be made, as the pumps pulled out so much sand under the sheet- METHODS AND COST OF TRENCHING 881 ing as to cause either the ditch to fill or the sheeting to cave in. The sheeting was put down to a depth of 10 ft. with a \vater jet in advance of the excavation, this being the only way the con- tractor could make any headway. Owing to the numerous " salt holes " encountered, through which the line at times ran, it was necessary to make a foundation for the manholes and pipe. This was done by piling spaced 7 ft. apart and 6 in. c. to c. On the piles 4 x 4-in. yellow pine, 8 ft. long, was spiked, and to this were spiked hemlock planks 2x8 12 ft. long. The pipe was laid on this and the hole filled with sand and salt hay. If a manhole was located at one of these " salt holes," 4 piles, 10 to 15 ft. long were driven 4% ft. c. to c. Four railroad ties were then spiked together 'with two pieces of batten, and the whole bolted securely to the piles. On this foundation \vas placed a box 5 ft. square and 10 in. deep, the bottom being covered with tongue and grooved floor boards, and in some cases lined with canvas and the inside covered with coal tar pitch. The concrete was placed in the box, the pipe line run through, and the brick work completed. As a general rule, water was struck in excavating the trench about 18 in. below the surface. The pipe laid was 8 and 12-in. terra cotta, hence the ditch was made only wide enough for a man to work in it easily, this width being 2 ft. for a ditch 6 to 7 ft. in depth. The method of excavating was as follows: By using the piston pump the sheathing was put down for a distance of 150 ft. along the trench, and a closure made at each end. Then 10 laborers were put in the trench and excavation made to the water line, when rangers and braces were set. The piston pump was then started pumping water into this " land coffer dam." A centrifugal pump was moved into position, and the discharge pipe placed midway in the last section, where the sewer pipe had already been laid. Thus tiie centrifugal pump excavated the material from the forward section and backfilled the last section at the same time. See Fig. 39. When grade was reached, the foundation piles were jetted down and the cradle constructed. The pipe was then laid, the joints being made with cement and tar. The next section was then done in the same manner. The sand excavated was quite coarse, and but little agitation was necessary with shovels, in order to allow the pump to pick up the sand. When the sand is fine grained, much more water is needed, and likewise the sand must be agitated with shovels. With extremely fine sand, the men must be relieved frequently, as 882 HANDBOOK OF EARTH EXCAVATION the work is hard, and, as the pumps take up a much smaller percentage of the sand, the ditch must be kept with a larger amount of water in it, and the men, being compelled to stand in the water, feel the effect of it quickly. At times when the contractor got as deep in the trench as the original ground surface, he encountered a considerable number of roots that had to be cut out, but this was seldom necessary. Cng-Contr Fig. 3. (1) Centrifugal Pump; (2) Boiler; (3) Piston Pump; (4) Pipe in Trench; (5) Trench Be- ing Excavated; (6) Suction Pipe; (7) Discharge Pipe; (8) and (9) Steam Pipes; (10) Pipe to Water Supply. Fig. 39. Arrangement of Plant for Excavation in Quicksand. Fig. 39 shows the layout of ihe plant to do the work in the manner described. In this way an average of 300 lin. ft. of trench was dug and pipe laid per day, while another contractor doing similar work by another method averaged only from 35 to 50 ft. per day. The cost of driving the sheeting and pulling it for the 300 lin. ft. of trench done per day was : Boss timberman % 2.50 Fireman on jet pump .- 1.50 One man setting sheeting 2.00 Two helpers, at $1.50 3.00 Three men pulling sheeting, at $1.50 4.50 One man carrying sheeting 1.50 Two men bracing trench, at $2.00 4.00 One man pumping 1.75 Coal and oil 1.00 Total $21.75 This gives a cost per lin. ft. of trench of 7 ct. for driving and pulling sheeting, and as there was 6,080 lin. ft. of sheeting driven and pulled a day, it makes a cost per lin. ft. of sheeting y 3 ct. With 2-in. sheeting used, the amount of timber was 6,000 ft. B. M., which cost $26 per M. This timber, being driven with a water jet, was used time and time again. The sound piles, which were from 10 to 15 ft. long, cost 25 ct. apiece, and the cost of driving them was 1.5 ct. per lin. ft. The cradle for the pipe was built by two men, each at $2 per day. They built 200 lin. ft. per day, which meant a cost per ft. METHODS AND COST OF TRENCHING 883 of trench of 2 ct. The amount of lumber in 200 ft. of cradle was 866 ft. B. M., which meant a labor cost for framing of about $5 per M. The lumber cost $26 per M. The daily cost of digging the trench and backfilling, and of laying the pipe was: Foreman, 10 hr $ 4.00 Eight men digging, at $1.50 12.00 Two men trimming, at $1.50 3.00 One engineman 3.00 One pumper 2.50 Two pipemen, at $2.00 4.00 Coal, at $5.00 per ton 1.25 Rent of boiler 2.00 Rent of pumps 2.50 Rent of engine 2.00 Two pipelayers, at $2.00 4.00 Two pipe carriers, at $1.50 3.00 One man on mortar and jute 1.50 Total $44.75 Each day this plant excavated about 200 cu. yd., hence the cost of excavation per cu. yd. was: Labor $0.047 Coal 0.006 Plant rental 0.032 Total $0.085 This is equivalent to 5.8 ct, per ft. This is a very low cost for excavating earth from a trench and backfilling it. The terra cotta pipe cost 16 ct. per lin. ft. and the hauling of it cost 2 ct. The total cost per lin. ft. of pipe laid was as follows, exclusive of manholes: Foreman $0.013 Excavating and backfilling by hand 0.050 Excavating and backfilling by pump: Labor 0.032 Coal 0.004 Plant rental 0.022 Driving sheeting 0.040 Bracing trench 0.013 Pulling and carrying sheeting 0.020 Piles in place 0.105 Cradle, lumber and labor 0.132 Pipe 0.160 Hauling pipe 0.020 Laying pipe 0.028 Materials for joints 0.013 Total per ft $0.652 This cost does not include any allowance for general expense nor for the materials used in shoring the sides of the trenches. The 884 HANDBOOK OF EARTH EXCAVATION sheeting was used many times, as driving the planks with a water jet did not injure the planks or break them up. The cost of this work in a ground difficult to excavate is ex- ceedingly low, and can be attributed to the methods used in carry- ing on the work. Backfilling Trenches. Backfilling on sewer work is not often given the consideration that its importance warrants. If the excavated material is placed on both sides of the trench it is sure to be walked over and compacted, often requiring picking before it can be thrown back into the trench. One man can back- fill 20 cu. yd. of loose material in 10 hours. It is frequently specified that there be one man ramming the earth for each two men shoveling. A man will ram 40 cu. yd. of loose earth in a day. In heavy clays, two rammers to a shoveler are often required. It is a mistake not to tamp around the pipe. This is often omitted because of fear of deranging the alignment or disturbing the joints. There is more danger of this being done through un- even settling of the backfill if this tamping is omitted. Tamping around pipe should be done carefully with a light wooden tamper. It is well to remember that the man tamping can consolidate almost as much earth with his feet as with the ram, and that it is of advantage to have him keep moving around. A very common method of compacting earth in trenches is by puddling it with water. This is usually cheap and effective. Care must be taken not to puddle before cement work has had time to set. Puddling should not be attempted in unstable ma- terials, such as muck or quicksand, where the trench bottom will become softened with the water and disturb the alignment of the pipe. There are a number of ways of backfilling trenches besides doing it by hand. Plows and scrapers of various kinds are used with success on small trenches. In open fields the bank carrying the excavated material can be caved in with a hose and water, thus filling and compacting at the same time. Work done in this man- ner will require finishing by hand or with scrapers. There are a number of light traction machines on the market, on the order of dragline excavators, which are especially designed for backfilling trenches. Where backfilling is done under paved streets the proper com- pacting of the fill is of great importance. This is a most fruit- ful source of dispute between the " city " and the " contractor." Valuable suggestions for avoiding this trouble will be found in the following abstract: METHODS AND COST OF TRENCHING 885 Backfilling for Water Pipe. At Corning, N. Y., a trench for a 10-in. water pipe was excavated 2,y 2 ft. wide X 5 ft. deep, X 1,500 ft. long = 600 cu. yd. in 4i/ days by 24 men, or at the rate of 6 cu. yd. per man per 10-hr, day, equivalent to 11 ct. a running foot or 25 ct. a cu. yd. The backfilling was done in 3 days by 2 men and 1 horse with driver, using a drag scraper and a short length of rope so that the horse worked on one side of the trench while the two men handled the scraper on the opposite side, pull- ing the scraper directly across the pile of earth. In this way 200 cu. yd. of backfilling was made per day at a cost of 2i ct. per cu. yd., there being no .ramming of the backfill required. This is a remarkably low cost for backfilling, and one not ordinarily to be counted upon. The material was a loamy sand and gravel. At Rochester, N. Y., size of trench and kind of material prac- tically the same as at Corning: 1 man excavated 8 cu. yd. a day at cost of 19 ct. cu. yd. 1 man backfilled 16 cu. yd. a day at cost of 9 ct. cu. yd. Total cost of excavation and backfill 28 ct.cu. yd. Backfilling Trenches Under Paved Streets. In Engineering and Contracting, Oct. 9, 1907, George C. Warren gives the follow- ing recommendations for backfilling trenches: In the case of permits to service corporations, plumbers and property owners, to cut into the streets, whether paved or un- paved (the former is but little more important than the latter), it is only necessary to stipulate in the permit that " The trenches shall be backfilled by such means as the city engineer may direct, depending on the character of the excavated material, in such a manner that all excavated material shall be replaced in the trench without raising the grade of the roadway. Flushing will only be permitted in cases where the sub-soil is sand or gravel or other material from which the surplus water will readily drain away, and in the case of concrete or brick sewers or pipe sewers, the joints of which have been made water-tight 'with bituminous cement pipe jointing cement." In the case of contract work for sewers, etc., the case is more difficult in view of the necessary uncertainty .of conditions to be met underground, and consequent uncertainty of the most economical way to properly " back fill " the trench and conse- quent impracticability of the contractor accurately figuring in advance what the cost per lin. ft. will be. On this account some contractors are sure to bid far too low to permit proper work. Others figure " safe " with the probability that if they receive the contract, the total price will be too much above the estimated cost. In one case the city has the almost impossible task of 886 HANDBOOK OF EARTH EXCAVATION forcing the contractor to do proper work at a loss. In the other case the city will pay too much for the work. An effort should be made to avoid both evils. My suggestion is to apportion the prices in such a way that whatever material is encountered a fair price will be allowed the contractor for each as follows: (a) Furnishing and setting pipes per lin. ft. (b) Earth excavation per lin. ft. (providing for varying prices for varying depths of sewer). (c) Rock excavation per lin. ft. (providing for varying prices for varying depths of earth). (d) Hauling excavated material to spoil bank (if unsuitable for backfilling and its removal directed by the engineer) per cu. yd. (e) Lumber delivered on work (if any is required for shoring) per M. B. M. (f) Placing and replacing (if lumber reused) in sewer trench per M. B. M. (g) Refilling trench by flushing earth excavated from trench per cu. yd. (h) Refilling trench by tamping earth excavated from trench per cu. yd. (i) Refilling trench by flushing suitable borrowed material (to replace unsuitable excavated material drawn to spoil bank by order of engineer) including furnishing the material per cu. yd. measured in the wagons as material is delivered. (j) Refilling trench by tamping suitable borrowed material (conditions the same as item "i"), per cu. yd. (k) Refilling trench with rock excavated from the trench per cu. yd. Corresponding with such a schedule of prices in proposal and contract, the specifications should provide as follows: 1st. Material excavated from the trench, which in the opinion of the engineer is unsuitable for backfilling, shall be hauled by the contractor to a spoil bank and shall be paid for at the price bid per cu. yd. for " hauling excavation to spoil bank," meas- urement to be made in the wagons at point where loaded. 2d. Flushing in back filling will be permitted only in case the material, is sand or gravel or other material, from which in the opinion of the engineer the surplus water will readily drain away and leave the earth filled solid. 3d. Except where flushing is directed by the engineer, the back- filling shall be done by thorough, hard tamping in layers not ex- ceeding six (6) inches in depth. Flushing will not be permitted except in cases of brick or concrete sewers or pipe sewers, the METHODS AND COST OF TRENCHING 887 joints of which have been made water-tight with bituminous pipe jointing cement. 4th. Whether backfilling of earth is done by flushing or tamp- ing the full amount of material excavated from the trench, less the volume of the sewer, shall be refilled into the trench without raising the grade. 5th. In case rock is excavated from the trench, it shall be back- filled by carefully placing the excavated rock in layers with suc- ceeding layers of earth well flushed into the voids between the pieces of placed rock. 6th. In case the excavated material is clay, which in the opin- ion of the engineer is too wet to enable solid backfilling by tamp- ing, the excavated wet clay and reasonably dry " borrowed " earth shall be tamped into the trench in succeeding layers, using enough of the dry earth to overcome the excess of water in the clay and to provide a solidly filled trench to the satisfaction of the engineer. The " borrowed " earth including tamping, to be paid for per cu. yd. of " borrowed material " tamped into the trench. Measurement of the borrowed material is to be made in the wagons as delivered on the work. Handling Backfill in Freezing Weather. The following in- structions given by C. P. Chase, City Engineer, Clinton, Iowa, were published in Engineering and Contracting, Aug. 4, 1909. (1.) It is much cheaper to thaw out ground with fire or steam than to pick frost. (2.) Watch frozen banks for caving when frost goes out. It will drop all at once. (3.) In backfilling frozen ground allow 20% more shrinkage than when dry. (This does not apply to rock.) (4.) Cover all work as fast as laid wi'th unfrozen earth, if pos- sible. (5.) Backfill and clean up as close to work as possible before excavating materials freeze. Methods and Cost of Backfilling. The cost of backfilling de- pends upon the nature and condition (whether frozen, wet, packed, or dry powder) of the material, the means employed for back- filling, and the amount of tamping required. If the material is left in the spoil pile for some time and is subject to rain and the trampling of men and horses, it may become so consolidated as to cause the backfilling to cost almost as much as the original excavation. When backfilling by hand the men should not stand upon the pile and shovel from beneath their feet, but should stand at the edge of the trench or ditch and should excavate the material by pushing their shovels under it. When the ground surface is very rough it will pay to lay down steel " slick sheets " 888 HANDBOOK OF EARTH EXCAVATION for the excavated earth to be thrown upon. This will later ma- terially decrease the cost of backfilling, as it is very much easier to slide the shovel along the smooth surface of the " slick sheet " than over rough ground. An efficient man shoveling backfill material, that is well broken up, into a trench not over 3 or 4 ft. wide or 6 or 8 ft. deep, will handle 20 to 25 cu. yd. in 10 hr. Observations show that in backfilling average loam, clay and sand materials, one man will handle 9 shovelfuls per minute, or about 0.045 cu. yd. or 1.2 cu. ft. per minute. This is at the rate Fig. 40. Drag Scraper Backfilling Trenches. of 27 cu. yd. per 10-hr, day. However, interference with the work and periods of rest required by the men will reduce this daily output. On the other hand, if shovels larger than No. 2 or 3 are used, the output can be increased. With loosened earth and the short throw required in backfilling the shovels used for backfilling should be larger than those used for excavation. In shallow trenches a team and scraper can drag the material directly into the cut. As a rule the scraper is operated on one side of the trench and the team on the other, the scraper being attached to the horses by a long rope or chain, and being pulled back by two men. Another method is to fill in narrow runways by hand across which a team can travel and to dump the earth METHODS AND COST OF TRENCHING 889 as close to the side of the runway as.it is possible. Fig. 40 il- lustrates this method as used. This method cannot be practiced successfully with any but the steadiest of horses. The Doane and Lehr scrapers, both of which are built of hardwood sheathed with iron, are used for backfilling trenches. They are broad and wide and dump easily. Buck or fresno scrapers can be used for filling shallow trenches. A wing plow, with a deep and long mold board can be used where a neatly finished appearance is not necessary. The earth being piled close to the sides of the trench is thrown in by the plow as it is pulled through. The horses may be worked first on one side of the trench and then on the other, or they may straddle the trench if a long double tree ia used. This is the cheapest method of backfilling. In sand and light clays the earth may be caved in with a hose and water. This method also leaves the trench with a bad appearance, and it should be trimmed off with scrapers. Fig. 1. Fig. 41. Trench at Gary, Ind. Fig. 41 illustrates a trench in sand at Gary, Indiana. The top 4 ft. of this trench were excavated with scrapers, and the re- mainder with hand shovels. Engineering and Contracting, Sept. 8, 1908, gives the following data relative to this work, The sheeting was of slab wood cut in lengths of 4 and 6 ft. The lower 2 ft. of trench being free from sheeting permitted the pipe laying to be done much more easily. In backfilling the trench dirt was shoveled in over the pipe and up to the lower waling; then the sheeting was taken out and a water jet turned on the banks; this caused them to cave in, bringing down into the 'trench the excavated material piled on the sides. This was followed by a drag scraper that leveled up the ground. The cost of digging this trench was 12 ct. for shoveling per cu. yd., and 4i ct. for shoring, making a total cost of 16^ ct. for excavating and 890 HANDBOOK OF EARTH EXCAVATION shoring, the pumping being extra. This is a low cost for exca- vating such a trench. The cost of backfilling was less than 4 ct. per cu. yd. When a team with a drag scraper attached by a long rope is used, about 15 cu. yd. per hr. can be handled, provided the gang is efficient. A team and driver and two laborers, at $1.20 an hour, will thus scrape earth back into a trench for 8 ct. per cu. yd. Ernest McCullough gives the following description of a method of using a hoisting engine and a scraper to refill trenches. The Fig. 42. Doane Scraper. hoist is set at one end of the street and a cable is run alongside the trench to a pulley fastened to a tree (first wrapped with canvas or burlap to avoid chafing) or to posts. From this pul- ley the cable goes across the trench and is fastened to the scraper which is larger and heavier than an ordinary drag scraper, and has ropes fastened to the handles, by means of which two men haul it back and turn it over. This requires an engineman who does His own firing, a boy to signal him, and the two scraper holders. The total cost for labor, fuel, etc., is about $10 per day, which includes interest and depreciation. One hundred yards per day is all that can be figured on steadily on an average, so that the cost will be 10 ct. per yard. By adding two more METHODS AND COST OF TRENCHING 891 scraper holders and working the men in 10 or 15 min. shifts, as much as 225 cu. yd. have been put into a trench in 10 hr. It is almost necessary to have an old horse to pull the cable back when the men haul back the scraper, or else have a double cable and a tackle. When the horse is used the signal boy rides him. The increase in expense is not great and it lightens the work of the scraper holders. Backfilling with a Keystone Traction Shovel equipped with a ditcher scoop has been successfully done by mounting a back- filling board on the scoop as shown in Fig. 43. In this way the scoop is converted into a power-operated drag scraper. Fig. 43. Ditcher Scoop of Keystone Shovel Equipped with a Backfilling Board. A Backfill Drifting Scraper. Engineering ' and Contracting, July 23, 1913, gives the following: This scraper, or so-called "go-devil," Fig. 44, was used for backfilling a trench on a 154- mile oil pipe line near Los Angeles, Cal. The machine was de- signed by James R. Kelly. The appliance was made of a share from a road grader and a handle was attached as shown. By means of chains of adjustable length the machine could be drawn by 4 horses. The labor required consisted of 1 driver and 1 guide- man. With this force about 5,000 ft. of trench, 3 ft. deep and 1.5 ft. wide, or 830 cu. yd. were backfilled per day of 9 hr., at a cost as follows : 892 HANDBOOK OF EARTH EXCAVATIOK 4 head of stock, at $1.50 1 driver 1 laborer $ 6.00 4.00 3.50 Total at 1.6 ct. per cu. yd $13.50 If an attempt was made to move too much dirt at one time great difficulty was encountered. Four to six rounds were usu- ally necessary for backfilling a 3 or 4-ft. trench. V"" Fig. 44. Drifting Scraper for Backfilling Trench. The Monahan Backfilling Machine. This is described in En- gineering and Contracting, June 17, 1914. Fig. 45 illustrates the Monahan. backfilling machine in operation. This machine comprises a self-propelling 10-hp. engine and boiler with winding drums, and a bucket or scraper that slides on a frame transversely. This bucket has a hinged bottom or apron that is tilted in operation like a slip scraper in filling. The tilt of this apron governs the depth of spoil removed. This bucket holds about ^ cu. yd. and can make 15 strokes per minute on the average. The Parsons Backfilling Scraper with Caterpillar Traction. This machine, Fig. 46, is described in Engineering and Contract- ing, Apr. 12, 1916. Its center of gravity is low. The cable pull is from the under side of the drum and is only 18 in. from the ground. Thus a great pull can be exerted without overturning METHODS AND COST OF TRENCHING 893 the machine. A 10-hp. gasoline engine is \used, giving a speed of 95 ft. per min. on the backfill line and A pull of 3,500 Ib. The scraper will work at the rate of four loads a minute. The weight in working order is 4,800 Ib. This machine is made by the Par- sons Co. of Newton, Iowa. Cost with Austin Backfiller. According to Alvin C. Vogt in Engineering and Contracting, July 19, 1916, one of three back- filling machines made by the F. C. Austin Co. of Chicago, 111., was used on sewer work in Norwood Park, 111. The trenches were 24 in. to 36 in. wide in stiff clay, and the backfilling was heavy Fig. 45. Monahan Backfilling Machine in Operation. work. The machine has a 10-hp. gasoline engine and is self-pro- pelling. The operating cost was $10 per day and the average fill has been 600 ft. of 10 to 16-ft. trench per day. The machine referred to is similar to the Parsons backfiller, except that it has ordinary traction wheels instead of caterpillar treads. The Waterloo Backfiller. Engineering and Contracting, Oct. 31, 1915, gives the following: The Waterloo " Double-Quick " gasoline machine, illustrated in Fig. 47, is used in backfilling trenches; for light hoisting opera- tions, hauling overground materials such a heavy timbers; load- ing, unloading and placing heavy pipe, valves, etc., in trenches; for cleaning sewers, and for pulling aerial and underground cables. 894 HANDBOOK OF EARTH EXCAVATION The machine probably finds its greatest field of usefulness in the backfilling of trenches. It has done this work at a cost as low as 2 ct. per cu. yd. The essential elements of the machine are an engine and a wind- ing drum; these are mounted on a turntable. This table swings easily and can be locked in any one of four position to permit the use of the winding drum from the front, rear or sides of the machine. At each setting of the turntable the scraper is readily operated through an arc of 90. A dead-man is furnished with the machine and so also are 300' ft. of %-in. manilla rope and a sheave. The machine moves along the trench under its own power by means of the rope attached to the end of the tongue and Fig. 46. Parsons Backfilling Machine. passing through the sheave on the dead-man and back to the winding drum. A ditching scraper also comes with the. outfit. With the scraper is supplied 50 ft. of %-in. steel cable which passes to the winding drum. The trucks are standard wagon gage and the wheels have wide tires. The total shipping weight is 2,630 Ib. A 4^-hp. gasoline engine furnishes the power. The speed can be varied by a change of sprockets on the crankshaft of the engine. The scraper travels 150 ft. per minute in common soil and 100 ft. per minute in clay soil. Two men are required to operate the machine when backfilling; one holds the scraper and the other the single controlling lever. The machine in operation possesses two incidental advantages of importance. It can be set on lawns or parking without dam- aging them when backfilling dirt piled on the side of the trench nearest the center of the street. In such cases teams cannot be METHODS AND COST OF TRENCHING 895 used for it is not permissible to drive them over the grass. The hoisting ability of the machine is utilized, also, in pulling out trench bracing which otherwise would have to be left in the trench. The machine is built by the Waterloo Cement Machinery Cor- poration of Waterloo, la. J. L. Bridges, in Engineering and Contracting, writes as fol- lows: On Center and High Streets in Decorah, Iowa, about 1,500 ft. of ditch, 8 to 131/2 ft. deep, 6 ft. wide at top (necessary be- SC*APCR ] m \ 1 \ I 1 I \ \sH **">{ x \ / / / / / / \ \ ' / / \ \ ' / 1 / / / r.,,,,,^,,, 7 .,j,,,, ,y \J-U7 / Fig. 47. Waterloo " Double Quick " Backfiller, Plan Showing Method of Operation. cause blasting caused banks to cave) in nearly solid rock, were filled with the Waterloo filler and two men in six days' time. About 300 ft. of this ditch stood open from November to April, and I have never seen a team that could handle a scraper under these conditions. There has been considerable work in the alleys here and we have used this backfiller very successfully where it would have been impossible to use a team on account of the width of the alley, it being only 19 ft. between buildings. What I value the most is the fact that we have the filler on the job all the time, wasting no time waiting for a team, thereby keeping the ditches filled ahead of rain and keeping the streets open to traffic. On straight, clean work, where there is plenty of room and enough to keep a team busy steadily, the cost of backfilling by 890 HANDBOOK OF EARTH EXCAVATION machine is approximately one-half of the cost of doing it by the team and scraper method. But on difficult work, and for short stretches where the team would not be available or would stand idle a part of the time, machine work costs from 10 to 40% of team or hand work. At Decorah, la., we used four machines, following two Austin trenchers and five hand crews, the latter working largely in rock. At Rockwell City, la., we laid 13,000 ft. of 4-in. water main in a 6-ft. trench in 13 working days, using two trench fillers, at a cost of 1 ct. per ft. for backfilling. The backfillers were hitched tandem following the trench machine. Fig. 48. Flushing Trench; Tamped Walls at Intervals. Puddling the Backfill. Engineering and Contracting, May 1, 1907, gives the following, After the first foot of backfilling has been tamped with a light tamping stick, the remainder of the material should be shoveled in and should be tamped in 6-in. layers by not less than one tamper to each shoveler. If water is available the best method is to build hand tamped walls across the trench at intervals of about 25 ft., fill the space between the walls half full of water and then shovel the earth into the water. A trench averaging 12^ ft. deep and containing a 48-in. main METHODS AND COST OF TRENCHING 897 was filled in the following manner: The trench was first filled with earth to within about 1 ft. of the top. An ordinary fire hose was then attached to a hydrant, the play pipe being about 20 in. long, with 1^-in. nozzle. A 2-in. meter was attached which allowed only about 75 gallons of water a minute to go through the hose. The pipe was shoved down into the trench within 3 ft. of the bottom and the water turned in until the ground settled. The pipe was then pulled out and shoved down again. When the ground stopped settling and the water came to the surface, the operation would be started over again 4 ft. or 5 ft. away, zig- zagging along the trench. After a sufficient quantity of water had been run into the trench it was evened off, the top material placed and rammed and the trench left fairly well . crowned. The trench in this case was 7 ft. wide and after letting it stay for about a week, a steam roller was run over it. The street was said to have been left in as good condition as it was before the excavation was begun. Tamping Clay. The following is from Engineering and Con- tracting, Aug. 11, 1909, Clay containing a little moisture is ideal material in which to excavate trenches, but is extremely difficult to compact prop- erly when refilling. As ordinarily placed back in the trench it occupies a much greater space than it did before being disturbed, and many wagon loads must be wasted. The clay placed in the trench always settles, sometimes occupying years in the process. Puddling is sometimes tried, but this method is only successful when the clay contains a large amount of sand. The best method of filling clay trenches is to place the loose material in thin layers around the pipes, tamping it carefully. Then put in loose material another foot deep. Pour in water until this material is barely covered. On this put enough material to hide the water and tamp it, adding dry material where soft spots appear, until the mass is firm. As long as mud appears the tamping is incom- plete. Then deposit another foot of loose filling, cover with water and tamp as before. Repeat these operations until the trench is full. If the work is properly done it will be necessary to borrow some material to complete the filling. The Cost of Backfilling and Tamping. Engineering Record, May 23, 1914, gives the following: The data were gathered by the Construction Service Co. Tamping was rigidly enforced. When water could be obtained sections of the trench were dammed at each end, the trench filled with water and the earth cast therein. For soils other than clay this is the most efficient method of compacting. The earth composing these dams was thoroughly tamped by hand. In one case water was used exclusively and the 898 HANDBOOK OF EARTH EXCAVATION cost of backfilling and puddling was 7.6 ct. (exclusive of the cost of water), wages being 15 ct. per hr. Short time observations on work gave the speed of tamping with ordinary hand tampers as 60 strokes per minute or 1 stroke per second. If the face of the tamper covered a fresh place in Fig. 49. View Showing Construction Tamping Machine. the trench on each stroke and the material was tamped in 6-in. layers, then one man would tamp 220 cu. yd. per day. This is manifestly impossible. As a matter of fact, the tamper is dropped repeatedly on almost the same spot, and one man will compact about the same amount that another man will backfill, namely, about 20 cu. yd. METHODS AND COST OF TRENCHING 899 Where the material is stiff dry clay and compactness is in- sisted upon, the amount tamped will be very small. In The Technic of 1896 costs of tamping are given. From the data we have deduced the fact that when the material (clay) was rammed dry in 4-in. layers the amount rammed per man was only 1.1 to 2.8 cu. yd. per day. The Stanley Tamping Machine. The Stanley power tamping machine is illustrated in Fig. 49. The description is taken from Engineering and Contracting, May 15, 1912. The tamper is lifted ^""" " ' "i**e. Fig. 50. A Pavement Picking and Trench Tamping Machine. up and allowed to drop by a simple mechanism similar to that used on drop hammers in forge shops. The tamper moves auto- matically across the trench and the movement along the trench is attained by moving the machine forward about 8 in. As regularly equipped the machine will work in trenches 1 to 4.5 ft. wide and tamp at a depth as great as 6 ft., but can be furnished with a special arm enabling it to reach a depth of 16 ft. The machine requires a crew of 2 men and consumes about 1.5 gal. of gasoline in 10 hr. The manufacturer states that 1,200 to 900 HANDBOOK OF EARTH EXCAVATION 1,500 sq. ft. per hr. can be tamped by the machine. If the ma- terial be compacted in 0-in. layers, and assuming that 50% of the time is lost, and that wages are $2 per day of 10 hr. and gasoline costs 15 ct. per gal., then 125 cu. yd. can be tamped per day at a cost of 5 ct. per cu. yd. The weight of the machine is 950 Ib. and the cost (pre-war) is approximately $300. The P. & H. Tamping Machine. Engineering and Contracting, Sept. 30, 1914, gives the following: This machine, Fig. 50, was made for purpose of providing a rapid and economical means of cutting through pavements where trenches are to be opened and also to tamp backfilled material at a low cost. The interesting feature of the machine is the ease with which it may be converted for service on one type of work Fig. 51. Chisel and Pick Heads and Tamper Head for Use with Power Picking and Tamping Machine. after use on another type. The only change necessary consists in substituting the pick or chisel point illustrated for the tamp- ing h^ad, also shown. A recent test of this device by the Wisconsin Telephone Co. of Milwaukee was conducted as follows: The machine was equipped with the concrete breaking pick and was tried out in competition with a hand picking gang. The machine removed 372 sq. ft. of G-in. concrete base in 410 min., an average of 0.91 sq. ft. a min- ute. By hand labor one man removed 23i sq. ft. in 71 min., an average of 0.33 sq. ft. a minute. On asphalt the machine cut 64 lin. ft. of groove in 26^ min., a rate of 72^ lin. ft. an hour, or in square yards of 36 in. wide trench, 16 sq. yd. per hour. Hand labor cut, in one case, 6 lin. ft. in 20 min., and in another 5 lin. ft. in 15 min., equivalent to 18 lin. ft. an hour or 2 sq. yd. of surface in the first case, and 20 lin. -ft. or 2.22 sq. yd. an hour, in the second case. METHODS AND COST OF TRENCHING 901 The stroke of the tamping head is 22 in. (average), the total weight of head and ram is 150 lb., and about 45 strokes per min- ute are made. The head travels a distance of 20 in. across the trench, enabling it to cover a trench 32 in. wide. When in use on the trench the machine is fed forward at the rate of 6 to 15 ft. per minute, and when traveling on the road 1.33 miles per hour is the speed attained. This machine can tamp in trenches as wide as 40 in., and as deep as 7.5 ft. It is made by the Pawling and Harnischfeger Co. of Milwaukee, Wis. Rolling Backfill. Engineering News, May 25, 1911, gives the following: Rolling backfill is sometimes successful, provided the trenches are not too deep. Fig. 52 illustrates a concrete roller used for Fig. 52. Concrete Trench Roller. compacting telephone duct trenches. After the ducts had been laid, 6 in. of dirt was carefully filled in around them and tamped. Then the remaining dirt was backfilled in layers of 6 in., each layer being tamped and rolled by a small concrete roller. On another section the earth was loosely backfilled and crowned about 6 in. above the roadway. Then a 10-ton steam roller was put on and the trench rolled. It is doubtful if this method of rolling the surface compacts the earth to a depth greater than a few inches or a foot. Trench Tamping with Pneumatic Rammers. C. M. Hartley, in Engineering and Contracting, June 7, 1916, gives the following: Where compressed air is available, the Crown floor rammers (type 22-SR), manufactured by the Ingersoll-Rand Co. of New York, may be used to good advantage. These machines, which consume 28 cu. ft. of free air per minute at a gage pressure of 100 lb. per sq. in., are easily operated by one man, who does not need to be a skilled laborer, and they do not require any great 902 HANDBOOK OF EARTH EXCAVATION amount of care to keep them in order, aside from cleaning and oiling. Comparative tests of hand tamping and machine tamping have shown that the cost of the latter is about one-third the former, and, at the same time, the backfill is much better tamped. We have backfilled a 50-ft. section of trench, 24 in. deep and 20 in. wide, containing 6.3 cu. yd., in one hour, with three men shoveling and six men hand tamping. This backfilling cost $1.80, or 28 ct. per cubic yard, and this ratio of tampers to shovelers insures good tamping. The hand tamping cost in this instance was 19 ct. per cu. yd. Another 50-ft. section 27-in. deep and 20-in. wide, containing 7.1 cu. yd., was backfilled and machine tamped in one hour, four men shoveling and one man running the rammer. I have never seen earth filling better compacted than it is by these tampers. The cost of this backfilling was 18 ct. per cu. yd., and of the tamp- ing alone, 6.9 ct. per cu. yd. Other tests have verified these figures, and we have found that, as a rule, the cost of tamping with these pneumatic ram- mers, on this class of work, is about 7 ct. per cubic yard. Bibliography. " Sanitary Engineering," E. C. S. Moore and E. J. Silcock ; " American Sewerage Practice," 3 vols., Leonard Metcalf and Harrison P. Eddy ; " Cost Data," Halbert P. Gil- lette; "Hand-book of Construction Plant," R. T. Dana; "Exca- vating Machinery," A. B. McDaniel ; " Practical Farm Drainage," C. G. Elliot. " Quicksand in Excavation," Charles L. McAlpine, Trans. Am. Soc. C. E., Vol. 10, 1881. "The Florence, Colorado, Water Works," R. P. Garrett, Eng. Rec., Feb. 10, 1900; "The Winston Salem Intercepting Sewer," J. N. Ambler, Eng. News, June 25, 1908; "Concrete Sewer Con- struction at Coldwater, Mich.," Harry V. Gifford, Eng. News, Jan. 30, 1902; "Light and Heavy Equipment on Identical Sewer Construction," Eng. News-K., Jan. 23, 1919; "Machine for Shal- low Excavation and Loading," Eng. and Con., Jan. 30, 1918. .Y/.?4'1bU k ;;>:' CHAPTER XVII DITCHES AND CANALS Types of Ditches. The word ditch is here used to indicate a small artificial open channel for the passage of water. A " ditch " dug for the purpose of holding an earth covered pipe conduit should be called a trench. The sides of ditches are sloped or so finished that they will withstand the action of water or the elements, while the sides of trenches have to be trimmed only enough to permit the use of sheeting or the entrance of the structure they are to contain. Large drainage and irrigation ditches are often called canals. Ditches, however, are channels with sufficient slope to discharge the waters they receive so rapidly that they will ordinarily be empty, whereas canals are channels of little slope whose slow rate of discharge makes them flow full continuously. The classes of ditches commonly constructed are as follows: Drainage Ditches are meant to carry water in the open ditch, for drainage purposes. When such ditches become wide and deep, they are no longer known as ditches, but are termed canals, al- though both in drainage and irrigation systems, all lateral canals are, as a rule, called ditches. Thus a ditch in one system may be of larger size than a canal in some other system. Gopher Ditches are small underground channels made with special plows. Their construction is possible only in certain soils. Irrigation Ditches. The remarks on drainage ditches are "ap- plicable to irrigation ditches. However, in irrigation work there are small ditches used between rows of trees and plants that tap the lateral ditches and carry water to the roots of the plants. Such ditches are made by hand or with a light turning plow, or some sort of scraper. Double Levee Ditches are a special type of irrigation ditch used where the land is very flat. Parallel levees are built of material taken from both inside and outside of the proposed canal, and water is carried between these levees at a height sufficient to flood the adjoining land. Roadbed Ditches. Ditches are excavated for drainage purposes in connection with both wagon roads and railroads. Small ditches are always made in cuts. For railroads these ditches are usually made 12 in. deep, 12 in. wide on the bottom and with 1 to 1 slope on the sides, making a ditch 3 ft. wide on top. This is for cuts through earth. Some engineers use the same size and kinoT for wagon roads, but as a ditch of this shape 903 904 HANDBOOK OF EARTH EXCAVATION has to be excavated by hand, the shape is changed on wagon roads so that they can be excavated by plows, scrapers, road ma- chines or elevating graders. 'This is done by carrying the slope of the roadbed to meet a shoulder of the side of the cut, thus forming a V-shaped ditch. Surface Ditches are excavated to prevent rain water from running into railroad or wagon-road cuts, or against embank- ments. These are generally small ditches, with the sides sloped, and are excavated by hand, the material from the ditch being thrown on the side of the ditch, between the ditch and the ob- ject it is to protect. Like roadbed ditches, these are paid for by the cubic yard of material excavated. These surface ditches are often termed berme ditches, but the author believes they should be called surface ditches in order to distinguish them from the ditches described in the next paragraph. Berme Ditches. In building railroad and wagon-road embank- ments, the material is often obtained from ditches on each side of the embankment, leaving a berme from 4 to 10 ft. wide beteween the toe of the embankment and the ditch. This berme gives the ditch its name. These ditches are excavated by hand, by scrapers and with elevating graders. Power Ditches are channels for carrying water from a dam or stream to a power generating plant or mill, and for taking the water away from the plant if it is not emptied directly into the stream. When used in connection with mills they are termed mill races, and the ditch carrying away the water is called the tail race. For electrical power generating plant the power ditch carries the water to a pressure pipe or penstock or a penstock pit. Such ditches are lined when it is necessary to prevent wasting water. Military Trenches are really ditches, as they are not excavated with the intention of filling them in. They are excavated, and the earth thrown up on the side of the ditch towards the enemy to protect the soldier. The earth thrown up is known as a breastwork. For temporary purposes the ditch is made wide and deep enough to obtain enough earth, so that when it is piled up it will stop a bullet, the soldier lying down or kneeling behind the breastwork in the trench. A Sap is a type of military trench, less used now than for- merly, which is dug by specially trained soldiers in advancing against an enemy under fire. Saps are dug advancing toward the enemy in an inclined direction, and changes of direction are made at short intervals to avoid enfilade fire down the trench. The work is advanced without exposing the men to fire and in order that it may be done as rapidly as possible the advance man DITCHES AND CANALS 005 works lying down and excavates a trench 15 in. deep ahead of himself. A second man works kneeling, and others follow who deepen and widen .the trench until troops can pass through it comfortably. Rifle Pits are small ditches, long enough to protect one or two men. Reducing the Cost of Drainage Excavation. Engineering Record, Dec. 26, 1914, gives the following: The reclamation of 488,000 acres of land in the Little River Drainage District in the southeastern part of Missouri involves the construction of many miles of flood-water diversion channels and impounding levees and 624 miles of open ditches for local drainage. These require a total excavation of about 42.800,000 cu. yd. of material. In general the material is excavated and deposited in final position at one operation by floating dredges, mainly of the dipper type, at an average contract price of 7.7 ct. per cu. yd., exclusive of the cost of clearing the land. This work is located in a territory averaging 10 miles wide and 90 miles long, most of which is continually or frequently submerged and is covered with a heavy second growth of tim- ber. There is a wide variation in the dimensions of the ditches and channels, which range in bottom width from 4 to 123 ft. and in depth up to 12 ft. Much of the work is too small for large dredges and too large for small ones to handle to the best advantage. Notwithstanding these conditions, prices satisfactory to the supervisors were obtained, chiefly through the method employed of classifying the work and arranging the contracts so that they could be handled advantageously and be adapted to continuous work by given units of plants. The fact that dipper dredges could be used for a large part of the excavation helped keep the cost down. The diversion work, consisting of deep wide channels and high levees, involved 8,621,591 cu. yd. of estimated excavation. The bulk of it was divided into two nearly equal contracts. The local drainage work involved about 34,208,101 cu. yd. of estimated ex- cavation and was divided into 27 contracts, awarded to 12 dif- ferent bidders. Governing Considerations. The classification and allotment of contracts was governed as much as possible by five principal considerations: (1) division of the work into units with chan- nel dimensions particularly adapted, to a standard type of machine, (2) allotment of sufficient yardage to each contract to give at least 2% years' work to a suitable machine and thus make the contract attractive, (3) location of an accessible build- ing site on some railroad at or near the head of each contract, 906 HANDBOOK OF EARTH EXCAVATION (4) provision for uninterrupted transportation of fuel to the excavating machines, and (5) elimination, as far as possible, of all upstream work. The 2^-year duration of contracts was unobjectionable for the small work. On the large work, where the bottom widths range from 81 to 123 ft., there is required a 4^-yd. excavating bucket and a 100-ft. boonl which, with its supplementary equipment, will cost from $40,000 to $75,000, and in order to reduce the cost per yard to reasonable limits an amount of work is required that necessitates the continuous operation of the plant for a long time. For these contracts this time was figured at three years, except in one instance where time limit was 40 months. In classifying drainage bids there is great advantage in di- viding the work into contracts before making the estimates of cost, because the combinations of different classes of work greatly modify their unit costs. For instance, a canal with a bottom width of 4 ft. may be 8-ct. work ; but when such work is placed in the same contract with ditches having 25-ft bottom widths, the cost of the 4-ft. width may be much increased because the re- quired width of a dredge suitable to excavate the 25-ft. canal will be much greater than that for the 4-ft. canal, and will necessi- tate considerable excess excavation. Dressing the Sides of Ditches. The dressing up of the sides of ditches is done for an entirely different reason than in the case of trenches. As ditches are to remain open, there are few cases where the sides should not only be well dressed but also sloped. The side slope is expressed as a ratio of horizontal to vertical measurement. Thus a " 2 to 1 slope " has a vertical rise of 1 ft. in 2 ft. horizontal. Ditches dug for irrigation, drainage and for power purposes should be made full size, and the banks should be sloped and dressed. A 1 to 1 slope is very commonly used, although this is varied from % to 1 to 2 to 1. Such slopes should be dressed up and trimmed, as the ditches can be kept clean easier. For irrigation and other purposes it is frequently necessary to line ditches. Measurements of loss by seepage made on a large number of irrigation ditches in California, show an average loss on main canals of about 1% for each mile that water is carried. On laterals in some cases the loss amounted to 11 and 12% per mile. At times the loss has exceeded 50%. In gravelly soil the loss is always excessive, and the water so lost from irrigation ditches and canals is more than wasted, as this water collects on lower lands, filling the soil and souring it, drowning the roots of trees and plants, and when it collects in pools, furnishing a place for the breeding of mosquitoes. The BITCHES AND CANALS 907 reader is referred to Engineering and Contracting, Dec. 2, 1908, for seepage data. The lining of ditches, besides preventing loss by seepage, ac- complishes three other purposes. First, the ditch can be kept clean easier. The smooth lining does not impede the suspended matter as readily as does an unlined ditch, nor do weeds and grass grow in the ditch to become a deposit of decayed vegetable mat- ter. The actual work of cleaning out the ditch is also easier. If a ditch is not lined, the edge of the ditch, even if it is made a straight line when constructed, soon becomes uneven and grown up with weeds and brush. This impedes the flow of water. The third effect of a lined ditch is to prevent the water from .... /01~.~. =j Plan / TfP "If- Countersunk bolts t -- ; ^ (S'c.toc. _ Part Ran E.ac. Fig. 1. Details of Slope Trimmer. :{;V >'"'*. ^y^,;>irf- washing the ditch deeper and scouring its sides or banks. Not only does the water in the ditch do this, but rain water falling on or near the banks washes them badly. However, a cheap lining will often prevent this as well as a more expensive kind. A dry stone paving, or even crushed stone spread over the bottom and sides of the ditch will serve for this purpose. An Irrigation Canal Slope Trimmer. Engineering and Con- tracting, May 3, 1916, gives the following: The device, Fig. 1, is a three-handled push knife 12 ft. long. The handles are 1%-in. pipe. The practice is to set to exact slope down the bank and 10 ft. apart l^-in. T girders. The trimmer is set on these tee tracks at the top of the slope and 908 HANDBOOK OF EARTH EXCAVATION pushed by the handles down slope, thus shaving the earth to an exact plane between the tees or girders. This trimmer showed considerable saving in labor compared with men using shovels. It was designed by U. S. Reclamation Service Engineers of the Carlsbad Project. Hand Excavation. The appliances described in Chapter XVI are meant for trench work, but some of them are also adapted to ditch construction. In sand, ditches can be dug entirely with a shovel. For this purpose a long handle shovel should be used with a large squire blade. Faster and cheaper work can be done by wetting the sand, whenever it is possible to do so, before the material is excavated, as much larger shovelfuls can be handled. In digging ditches for drainage work the ground is always wet and frequently is saturated with water. The ordinary shovel for such work is not a good tool as more spading is done than shoveling. Hence a spade is preferable. The short handled spade is in common use, though more efficient work can be done in many cases with a long handled tool. With a solid blade in wet material the spade is difficult to handle, as the suction on it causes either very slow work or else breaks the tool. For this reason, the skeleton blade for a spade has come into common use, as with it this suction does not occur ; and not only is rapid work done, but there is little chance of breaking the spade. The blade is also made much longer than the ordinary shovel blade, so that it is possible to dig a narrow and shallow trench, except the finishing, with this spade at one stroke of the tool. With a spade in soft materials a pick or mattock is not needed, as both the shoveling and digging are done with the spade. In wet plastic material the pick is of little use; a mattock does better work. A mattock is also needed where roots or old stumps are encountered. It is also used to trim the sides of open ditches, which should always be given good smooth slopes. Spading Wet Soil. When ditching in wet ground, filled with grass roots, making hard spading, L. Z. Jones, in the transac- tions of the Illinois Society of Engineers and Surveyors, 1903, says that a narrow bladed hay knife should first be used, pushing it as deep as possible along each side of the trench. This cuts the roots so that each spadeful has one side free. A three cor- nered piece of earth should then be spaded out, the spade being turned right and left alternately. This makes easy digging. A flat spade should not be used, for it will not hold sufficient earth. Use a long-handled round point mining shovel with an air hole in the middle to facilitate the removal of wet soil, and a long or short ditching spade according to the depth of cut. In tough DITCiiES AND CANALS 909 clays nothing equals the three-tilled skeleton spade, as this enters easily and is self-cleaning. To remove the loose earth from the bottom of the ditch use a tile scoop or cleaner. One can be made from an old scoop shovel by bending it like a sun-bonnet, and riveting on a bent shank so that the scoop will hang like a hoe. Fasten the shank to the large end of a buggy shaft and put a D-handle on the small end of the shaft. Have all tools very sharp. Special Ditching Machines. Although every type of equipment is used with success in digging ditches the following classes of machinery are specially adapted to this sort of excavation: Fig. 2. Buckeye Traction Ditcher for Open Ditches. Wheel Excavators. These are similar to the trenching ma- chines described in the last chapter except that instead of having their excavating buckets fixed on a chain they carry them at- tached to a wheel, like spokes. The buckets move in the line of the ditch. Template Ditch Excavators. These excavate by means of buckets moving across the line of the ditch. Land Dredges of the drag line and steam shovel types specially mounted for ditch work. Capstan Plows. These are heavy plows drawn by cables. Buckeye Excavator for Open Ditches. Fig. 2 shows this ma- chine. Two men are required to operate the machine, besides one 910 HANDBOOK OF EARTH EXCAVATION man with horse and wagon to haul fuel and water. For a 12-ton machine only 800 Ib. of coal are needed per 10-hr, day. With this plant and crew a ditch 3} ft. deep, 2 ft. bottom, and 4% ft. top was excavated at the rate of 5 lin. ft. per min., work- ing in wet and very soft ground at Raeeland, Louisiana. The ditcher is self-propelling and can be used for draining swampy lands, for cleaning out old ditches, and for digging the side ditches for roads. Cost of Operating Wheel Type Excavators in Drainage Ditch- ing. D. L. Yarnell in Engineering and Contracting, June 26, 1916, gives the following: Fig. 3. Rear View of Ditcher. Two machines of the wheel type designed to cut a ditch 4 ft. deep, 4 ft. wide at the top, and 2 ft. wide at the bottom, were used on the excavation of some ditches in one of the Gulf States. Each machine was driven by a 28-hp. gasoline engine. The digging wheel was 15 ft. in diameter and the two apron tractors each 5 ft. by 12 ft. The weight of each excavator was about 30 tons. The first cost of the machine was $5,500 and freight to the point of use was $338, making the total cost of each machine $5,838. The soil was a hard, yellow, sandy clay overlain by a turfy muck, varying in depth up to 2y 2 ft. The turf was easily cut, but the hard clay caused excessive wearing on the bearings. A large part of the work was done when water DITCHES AND CANALS Oil was from 2 to 3 ft. deep on the land. The total length of the ditches dug was 165 miles, the average length of ditch being 2,475 ft. The average depth of digging was about 4 ft., with a 4-ft. top and 2-ft. bottom. The average distance dug per shift of 10 hr. of actual running time was 2,250 ft.; the maximum distance dug in 10 hr. was 6,600 ft. The average yardages per month for the two machines were 13,245 and 13,180 cu. yd., respectively. The average daily outputs on the basis of the actual running time Fig. 4. Large and Small Ditch Sections Possible with the Same Machine. were 1,000 and 1,126 cu. yd., respectively. A part of the time the first machine ran a double shift, which accounts for the higher monthly and less daily average. It required 13 months to com- plete the work, the actual time of operation being about half this. On account of the excessive wearing on the bearings, caused by the heavy sandy clay, it was necessary to make frequent stops for rebuilding the machines, which operation occupied an average of nearly two weeks. Ihe total excavation was 317,162 cu. yd. 012 HANDBOOK OF EARTH EXCAVA'i IOX The daily operating expense per 10-hr, shift for each machine was about as follows: One operator, at $100 per month $ 4.00 One assistant 2.00 50 gallons gasoline, at 16 ct 8.00 Repairs 6.00 Other charges 12.00 Total per day $32.00 The itemized cost for operation for the entire work was as follows : Labor $ 5,172.11 Interest, discount, and exchange 202.05 Maintenance and repairs 2,860.08 General expense 273.10 Management expense 1,600.00 Provisions and cooking (cook's wages) 2,245.91 Freight and express 75.74 Towing 458.19 Gasoline 1,792.22 Other oil 281.49 Teams and livery 932.11 Telephone and telegraph 25.29 Motor boat operation 540.96 Interest and depreciation on machinery 5,185.00 Total at 6.82 ct. per cu. yd. $21,644.25 Machine Machine No. 1. No. 2. Running machine $ 917.97 $1,509.66 Repairing machine 1,431.37 771.96 Moving machine 105.20 88.51 Machine bogged 156.90 190.54 Total $2,611.44 $2,560.67 The excessive cost of labor given for the machines when bogged was due to the frequent crossings of a wide, muck-filled bayou which ran the entire length of the district. This bayou was about 1,500 ft. wide; the muck ranged from 5 to 15 ft. and was very soft. No tree roots, submerged timber, or stumps were en- countered. The work covered an area of about 7,000 acres, ap- proximately square, which was traversed by parallel canals every half mile. The ditches cut by the excavators were at right angles to these canals and were spaced 330 ft. apart. It was thus necessary to turn the machine around and run it light 330 ft. for each half mile of ditch cut. The item " moving " is for taking the machine across the canals and for moving from one part of the district to another; it does not refer to the moving between adjacent ditches. Another machine worked on comparatively solid ground. Power was supplied by a 28-hp. gasoline engine. The first cost was DITCHES AND CANALS 913 $4,000, and freight charges from factory to works were $350. After the machine had been operated for a short time it became apparent that the excavating wheel was far too light and a new wheel was substituted. The soil was a silt loam, firm and uni- form but not tenacious. No special difficulties due to soil con- ditions were encountered in this work. The chief obstacles to rapid progress were at first the weakness of the light excavating wheel, and afterwards the extra-heavy excavating wheel which unbalanced the machine. The tractors were larger than neces- sary and often broke down when turning on the hard ground. At the time the following cost records terminated, the work had been carried on intermittently for about 18 months; about one- half this time was occupied in repairs. During this time the machines dug 117,000 ft. of ditch 4% ft. deep, 45,500 ft. 3^ ft. deep, and 9,250 ft. twice over, the machine making two 4%-ft. cuts side by side. The average length of ditch cut per day was 800 ft., while the maximum was 1,950 ft. The daily cost of operation was as follows: Labor $ 5.50 Fuel 4.20 Incidentals 0.50 Repairs 2.40 Total per day $12.00 The average excavation per day was 410 cu. yd., Imsed on the average of 800 ft. of ditch, 4i ft. deep, 4^ ft. wide at the top, and 20 in. wide at the bottom. The machine excavated 82,330 cu. yd. in 18 months at the following itemized cost: Gasoline based on 215 actual days' operation $ 903.00 Repairs, actual cost 860.00 Incidentals at 50 ct. per day 120.25 Labor of foreman, 18 months, at $75 per month 1,350.00 Other labor, two men, $2.50 per day for 250 days 625.00 Interest and depreciation '. ... 2,675.25 Total at 7.93 ct. per cu. yd $6,533.50 Low Costs of Ditching in the Evergtodes. W. J. Kackley in Engineering Record, 1914, gives the following: Fig. 5 shows a ditcher which is now operating on the property of the Everglades Sugar & Land Company in Dade County, Florida. This machine was built by the Buckeye Traction Ditcher Com- pany, of Findlay, Ohio, but was completely remodeled by our forces to meet the conditions as found in the Everglades. The machine weighs 37 tons and is equipped with a 45-hp. gasoline engine. The bearing on the ground is approximately 350 Ib. per sq. ft. 914 HANDBOOK OF EARTH EXCAVATION Living quarters are provided for the crew on top of the ma- chine. This house will accommodate eight men. An independent electric generator furnishes light for the living quarters and for a searchlight, which makes it possible to run at night. The machine cuts a ditch 9 ft. wide on top, 2} ft. wide at the bottom and 5 ft. deep at an average rate in sand and muck of 8 ft. per min., or 480 cu. yd. per hr. It has cut 1 mile of ditch in 10 hr., or 528 cu. yd. per hr. Our records for December, 1913, show a total of 43,030 cu. yd. of material excavated at a cost of 2.9 ct. per cu. yd., including overhead expense, fixed charges on the machine and cost of clearing line. Some exceptionally Fig. 5. Ditching Machine with Quarters for Eight Men Used in the Florida Everglades. hard sand cutting and heavy clearing were encountered during the month. From Jan. 1 to Jan. 23 the machine has excavated 58,630 cu. yd. of sand and muck at a total cost of 2.4 ct. per cu. yd. Owing to the fact that the muck soil is too soft and spongy to permit of transportation by animals, the machine must carry supplies for an 8-mile run, 4 miles out from the canal and back, cutting in both directions on lines % mile apart. The Stockton Ditcher. This machine, Fig. 6, is unique in that it can excavate and widen a ditch by taking off successive slices. This enables the machine to be used for digging trenches or wide canals or for stripping areas. The limit of the width that can DITCHES AND CANALS 915 be removed depends upon the length of the belt conveyor, as the spoil bank will eventually interfere with the operation of the ma- chine. The machine is fitted with caterpillar traction enabling it to travel over very soft ground or to span a ditch 6 ft. wide. Fig. 6 shows the machine widening a ditch in soft peat soil. The machine is manufactured by the Stockton Ditcher Co., Stockton, Calif. Fig. 6. Stockton Ditcher Widening a Ditch in Soft Peat Soil. The Austin Template Excavator. The distinguishing feature of this machine (Fig. 7) is that it is designed to cut a ditch true to grade having banks sloped to any desired angle, with the spoil bank at a sufficient distance from the ditch to prevent the banks from caving. This machine constructs a ditch of practically any depth, width of top or width of bottom desired, and slopes the sides to any angle at a single operation. The waste banks are also constructed at a distance from the ditch, and it is possible to make them serve as continuous dikes, in this way increasing the capacity of the ditch during times of flood. The machinery is. run on temporary rails, laid one on each side of the ditch. The ma- chine can operate either up grade or down. The work can be done whether there is water in the ditch or not. An advantage claimed 916 HANDBOOK OF EARTH EXCAVATION . .} sii DITCHES AND CANALS 917 for this machine is that being carried on a track, it travels in a straight line, making a perfectly straight ditch. A frame work upon which the digging buckets operate is made to conform to the shape and size of the ditch, thus acting as a template for shaping the ditch as it is being excavated. A berm from 10 to 15 ft. wide is left between the top of the slope of the ditch and the spoil bank. The excavating buckets, two in number, are mounted on wheels, and they cut in opposite directions, one always being in readiness to dig while the other is dumping its load. The guiding frame is fed down automatically to any depth desired within the capacity of the machine and is under control of the operator. The guiding frame can be elevated above the surface of the ground and the excavator can thus be carried across the coun- try 'under its own steam on a temporary track. So rigged, it can be moved a mile a day. The machine is made of steel. It can be run on rails, mounted on a walking device, or on a pon- toon or boat, but its best work is done when operated on rails. It takes four men to handle this excavator. An engine- man, a fireman and two men to care for the track. This machine is made by the F. C. Austin Co. of Chicago. The Judkin Ditcher. This machine (Fig. 8) is a dry land excavator consisting of a car w r hich runs on rails, one being laid on each side of the trench. A steel frame extends under the machine and over it. On this frame in front is an endless chain carrying a series of plows. At the rear of the frame are two belts running in opposite directions. The endless chain runs transversely to the direction of the ditch, being controlled by pulleys, so the lower half of the frame will conform to the cross section of the ditch. The general method of operating this machine is similar to that of the Austin, the ditch being cut in sections, the frame being raised up to the surface after a section is excavated, and work started on a new section. " At the back of the car, transversely to the direction of the ditch, is a triangular shaped cutting frame, the lower part of which is constructed to conform to the bottom and slopes of the proposed ditch. Over each half of this frame are two chain belts, 30 in. apart, and between these belts are riveted at equal distances 14 buckets, which excavate and carry the material. The cutting edge of these buckets can be detached from the main part for sharpening if occasion requires. The buckets over each half of the frame travel in opposite directions, so that each set passes up the slope of the ditch where it does the excavation. Their direction is changed at the apex of the triangle by 918 HANDBOOK OF EARTH EXCAVATION sheaves, each bucket making a complete revolution every 45 sec- onds, although in easy digging they can be run at a speed of two revolutions per minute. The excavating frame can be put to- gether in such a manner that it will cut a narrow or wide bot- tom, or a different slope. The excavated material is cut up very fine and deposited on either bank. The spoil banks have uniform slopes coming to a sharp edge at the top. " Strips 30 in. wide are excavated at a time, and after the ma- chine has made an advance of 30 ft. it goes back over the ditch to clean up the loose material and the slopes. Then it goes Fig. 8. The Judkin Ditcher. ahead once more. In the center of the ditch there is left a small ridge of earth, caused by the excavating buckets crossing. This can be shoveled out by hand or the water will wash it away, extra earth being taken from the bottom to allow the material in the ridge to bring the bottom back to grade. The entire machine is under one man, but he has a fireman, an oiler, a man and team for hauling water and 4 men and team for moving track, which is laid in 30 ft. sections." The description of this machine is taken from a bulletin of the Northeastern Experi- ment Farm of the University of Minnesota, where one of them used at Bowesmont, N. D., is described. DITCHES AND CAtfALS 010 An average of two tons of coal for a day's run of 14 hr. is required. This machine, in a 33 days' run of 14 hr. per day, made an average of 1,449 yd. per day, or a little over 100 cu. yd. per working hr. The machine has a total weight of 60 tons, will cut a bottom 7 to 10 ft. in width with side slopes 1% to 1. Ditch Excavation with Templet Excavators. D. L. Yarnall, in Engineering and Contracting, Feb. 9, 1916, gives the following: A single-bucket templet excavator w r as used in southern Louis- iana on the construction of 7,825 ft. of ditch having a 24-ft. bot- tom width and ranging in depth from 3.5 to 7 ft. The side slopes were 1 to 1, and the width of berm was 15 ft. The total excavation was 43,128 cu. yd. The total cost of this machine on the work was $8,506. The soil was a yellow clay with a few spots of gravelly clay, and the top soil was baked very hard. No special difficulties were encountered except that considerable cribbing was necessary to level up the track supporting the ex- cavator when crossing natural water courses. Except for these streams the ground was level. Some trouble was also experi- enced with the traction device, due to the fact that the ditch was larger than that for which the machine was designed. The ac- tual number of working days was 128 days, of which 73 were spent in actual digging. The cost of operation per day was as follows: One operator, $3.85; one fireman, $2.28; three deck hands, $0.27; one team and teamster, $5.40. Total per day, $17.80. The aver- age daily excavation for the number of days worked was 107 ft. of ditch or 337 cu. y 1. The total cost of operation for 5 months was $3,500. Interest and depreciation in that time, at 41% per annum, would amount to $1,452, making the total cost $4,953 and the cost per cubic yard 11.5 ct. The operating cost was distributed thus: Labor, operating $1,885.25 Labor, repairs 294.48 Material, operating '. . 496.03 Material, repairs 222.99 Fuel 601.84 Total operating cost at 8.1 ct. per cu. yd $3,500.58 Land Dredges. These machines may be divided into two types : ( 1 ) Those moved on wheels or caterpillar traction, or travelling on rollers, and (2) w r alking dredges. The term includes almost any kind of locomotive crane or travelling derrick operating a dipper or bucket, and used for the excavation of ditches. The disadvantage of the land dredge, as compared with the floating dredge, is that it is impossible to use one in excessively soft ground. Platform traction wheels, however, will enable a dredge 020 HANDBOOK* OF EARTH EXCAVATION to travel on moderately soft ground. The chief advantage of the land dredge is that with one of these machines it is possible to begin digging a ditch at any point. With a tloating dredge, excavation is usually begun at the head of the ditch in order that there may be sufficient water to float the hull. If work is abandoned at any time that part of the ditch already dug is in most cases useless. In fact, it may be a detriment, for an un- usual flood would carry a large volume of water to the point where the ditch ended and possible cause considerable destruction to property. The land dredge can start work at the outlet of a Fig. 9. Gopher Traction Ditcher. ditch, and, as far as dug, the ditch becomes a useful work, drain- ing the land through which it flows. The Gopher or Straddle Ditcher. This machine (Fig. 9) is built by Mayer Brothers, Inc., Mankatp, Minn. The machine is mounted on two steel beams that straddle the ditch the machine digs. The four outer ends of these beams are each provided with a two-wheeled oscillating truck. The wheels are 2 ft. high and 18 in. wide. They run on plank track 6 in. thick, 3 ft. wide in six sections, each 20 ft. long. One section on each side is always loose and the sections are moved forward by two special cranes with which the machine is provided for this and DITCHES AND CANALS 021 other purposes. The planks are wide enough to hold the ma- chine up on the softest ground and slough. The dredge will dig 12 ft. deep and 22 ft. wide on firm ground. It will deposit the dirt 32 ft. out from the center of the ditch to the center of the bank to either side, making it 64 ft. from center to center of said bank. The dipper will swing free over a bank 14 ft. high. The machine is pulled ahead with a cable from the engine hooked to the track from both sides, and run to a dead man ahead of the dredge. The moving is done without interfering with, or stopping the work of digging. The total weight of the dredge is about 25 tons, and it is equipped with a dipper hav- ing a capacity of one cu. yd. It is stated that the dredge will excavate from 500 to 800 cu. yd. of earth in 10 hr. This machine is meant to operate either in dry material or where there is water in the ditch. The King Ditcher. Another type of dipper machine is known as the King Ditcher, manufactured by the Marion Steam Shovel Co., of Marion, Ohio. This machine is for dry land excavating. However, water will do no harm unless it is high enough to in- terfere with the working of the machinery. The boiler, engines and boom are all mounted on a large drag or mud boat. As the hull is comparatively narrow, easily ad- justible jackarms are placed on each side of the machine to prevent it from tipping. It is provided with a pair of inde- pendent cable drums with cables attached to anchors placed in the ground on each side of the ditch. By this means it is pro- pelled along the ditch as fast as the material is thrown out. It can be used on any kind of work, from soft material to the hardest clay or hardpan, and material may be dumped into cars or carts, or deposited on the banks as required. The material is dug with a regular steam shovel or dredge dipper. This ditcher is adapted for excavating lateral ditches, where there is not sufficient water to float a dredge, or narrow trenches or ditches where little or no slopes are needed. For large ditches, especially, with water in them the Marion Steam Shovel Co. makes floating dredges of various sizes and capacities. They also mount some of these dredges with dipper capacities from 11/4 to 2^ cu. yd. and with booms from 35 to 70 ft. long, on wheels. These are known as Traction Dredges. Under each corner of the dredge is placed a small four-wheeled car or truck, and these cars run on, two rails or a track laid down for that purpose. By means of cables the dredge is propelled. The platform or hull is of such width as to make the use of bank spuds or jack screws unnecessary. The Fairbanks Walking Dredge. Engineering News, Apr. 26, 922 HANDBOOK OF EARTH EXCAVATION 1011, describes a ditching machine (Fig. 10) that is made by the Fairbanks Steam Shovel Co., of Marion, 0., and is known as a " walking dredge." This machine is designed to excavate ditches where it is impossible to get enough water to float an ordinary boat. It does not require any track or rollers to move it ahead. The machinery is placed on a timber hull or platform well braced, to go over the constructed ditch and the boom is operated like that of an ordinary dredge by a turntable. The shovel, which is the digging part of the machine, is shaped very much like a slip or drag scraper. It has a capacity of from Fig. 10. View of Walking Dredge for Dry Ditching. one to two yards. It is attached to a long arm, which is let down to the ground and the shovel is filled by means of a drag line from the engine. The shovel has two tails and two lines on it. The second tail keeps the shovel in an upright position as it is being loaded, and by releasing the line the load is dumped. A somewhat similar machine to this and also called a walking dredge, has been used in Minnesota on ditch work. This ma- chine has a second boom, known as the walking beam, suspended from the boom. Pivoted on the' end of the walking beam is the shovel arm, and the shovel or scraper instead of working to- ward the machine as in the Fairbanks dredge, when loading works away from it. This is accomplished by pulling with a DITCHES AND CANALS 923 chain on the upper end of the shovel arm. The load is released by a pull on a chain attached to the bottom of the shovel arm. " " The peculiarity of this machine is the method of moving. Under each corner is a timber platform the shape of a stone boat, called a foot (Fig. 11). Each of these corner feet is 6 ft. wide, 8 ft. long and 4 in. thick. They are joined together transversely by a light timber. This requires them both to HOf My Fig. 11. Corner Foot of Walking Dredge. move in the same direction, the direction being controlled by a chain which runs from each corner foot to a drum that is op- erated by the craneman. Near the outside of each corner foot there is a knife made of iron, one-half inch thick by 6 in. wide and 6 ft. long, which prevents the foot slipping sidewise. Midway of the machine on either side is a center foot 6 ft. wide, 14 ft. long, 6 in. thick. On the under side a 6x6 in. timber 924 HANDBOOK OF EARTH EXCAVATION is bolted crosswise, to prevent slipping back. This foot is at- tached to a heavy triangle frame, free to move longitudinally between the double side frame of the hull. A chain, the end of which is attached to the side timbers of the hull, passes over two pulleys in this triangular frame and then passes along the hull to the back corner and across the back end to a drum which is located about the center of the hull. When it is desired to move the machine the power is turned on to this drum and the chain wound up. As the chain tightens, the hull of the ma chine rises, the weight coming on the center foot. The winding on the drum is continued until the weight in lifting the hull becomes greater than the friction at the corner feet, when the entire hull moves ahead about 6 ft., although an 8-ft. move can be made. The chain is then released, taking the weight off the center ^foot, which is pulled by another chain attached to a drum in the front part of the hull. " This machine, when not digging, has moved across country at the rate of one mile in 11 hr. While working, the machine threw 7 shovels of dirt and moved ahead 6 ft. 8 in. in 7 min. It worked at this rate several times and this seemed to be about an average speed. Short bends cannot be made, as the feet^ are liable to slip into the ditch and wet caving material causes trouble. When the banks are dry and firm there is no difficulty in moving." The Monighan Walking Excavator. An excavator which is mounted upon a tractor device having a " walking " motion instead of being mounted upon rollers or wheels, has been brought out recently and is used especially in land drainage work. The advantages claimed for this method of moving the machine are in giving a much larger bearing area than rollers, wheels, or caterpillars; and in giving only a direct pressure upon the ground, thus avoiding the tearing up and churning of soft soil by wheels or caterpillars. It requires no tracks for wheels and no skids or plankways for rollers, and thus dispenses with men required to handle such auxiliary parts. The machine can travel in any direction and can change its direction readily,, turning angles or curves without any skidding. The mechanism for moving comprises few parts, which are large and substantial and not liable to wear. The excavator is of the drag-line type and is shown at work in Fig. 12, while Fig. 13 shows the details of the tractor or traveling device. The steel frame carrying the machinery and boom revolves upon a turntable or circular base which rests on the ground and forms the support of the machine when work- ing. The bottom of this base frame is covered with steel plates, DITCHES AND CANALS 925 so that it provides a large bearing area. Across the upper or re- volving frame extends a 9-in. shaft carrying at each end a cast-steel sector A, to which is pivoted a lifting beam B. From this beam is suspended the shoe or platform C, which has a steel frame shod with plank. Upon the shaft is a large spur wheel D, gearing with a pinion which is mounted on the shaft of the loading drum and is fitted with a jaw clutch and a band brake. When the machine is excavating, there is no load upon the shoes, which are swung clear of the ground, the entire weight being carried by the base of the turntable. When the machine is to be moved, the pinion clutch is thrown in and the engine Fig. 12. Monighan Walking Excavator. When working, the weight is carried by the solid-base turntable frame A. When moving, the weight is carried by the two shoes B B. started, thus driving the cross-shaft. As this revolves, the sec- tors and beams lift the side shoes and swing them 8 ft, forward, till they rest upon the ground. The continued revolution of the shaft causes the sectors to ride or rock upon steel plates on top of the shoes, the entire weight of the machine being thus transmitted to these shoes while the machine is lifted bodily and shifted 8 ft. forward. The total advance is thus 16 ft. When the movement is completed, the sectors lift the shoes clear of the ground, and the machine is again carried upon the broad base of the turntable. The clutch is then released, and the machine resumes work. As the shoes are carried by the revolving frame, there is no skidding in turning the machine at an angle or curve. With 920 HANDBOOK OF EARTH EXCAVATION the shoes raised clear of the ground, the machine is revolved into the desired line of direction, the shoes being then lowered and the machine advanced in this line. Thus it is readily mov- able in any direction, and wide ditch work can be handled with a comparatively short boom, the machine working alternately on opposite sides of the center line of the cut. The shorter boom permits of a larger bucket and greater excavating capacity. As the shoes are raised about 2 ft. from the ground, it is easy to place timbers or earth filling beneath them if required in very soft ground. Fig. 13. Walking Mechanism of Monighan Walking Excavator. The machine shown in Fig. 12 is at work on a drainage ditch 3i/ mi. long, near Wheeling, 111., the contract involving about 100,000 cu. yd. of excavation. The ditch is 10 ft. wide on the bottom, with side slopes of 1:1 and a depth of 5 to 10 ft. There is a 15-ft. berm and a spoil bank on each side for the greater part of the distance, but in some places these are on one side only. The machine has a 50-ft. boom and handles a 21^-yd. scraper Bucket. Its turntable track is 17 ft. diameter. The two shoes or side platforms are 20 x 4 ft., each composed of two 12-in. I-beams with %-in. cover-plates on top and 3-in. oak planks bolted to the bottom flanges. The boiler is of the locomotive type, carrying 125 Ib. pressure DITCHES AND CANALS /?.] 927 and there is a 750-gal. water tank. The weight of the machine is about 65 tons. A larger size is made, having a 24-ft. turn- table, 65-ft. boom and 3%-yd. bucket; this weighs about 85 tons. The machines may be operated by gasoline engines or electric mo- tors if required. These " walking " drag-line excavators are built by the Moni- ghan Machine Co., of Chicago. The walking mechanism is the invention of 0. J. Martinson. Ditching with Special Plows. The simplest ditch can be dug with an ordinary plow. For this purpose a turning plow is used. A furrow is turned from 6 to 10 in. deep, and the plow in re- turning throws the earth in the opposite direction, giving a ditch on the bottom from 6 to 12 in. in width. The earth is thrown to each side of the furrow. A better ditch can be excavated for either drainage or irriga- tion work by first plowing four furrows with an ordinary plow and then by using a shovel plow, which has a square bottom mold board, flat like a shovel with a 14 or 16-in. blade, the plowed earth is pushed to each side, leaving a ditch from one to two feet wide and from 8 to 12 in. deep. A wing plow, which has a long mold board, can also be used to excavate a ditch. More efficient work can be done by first plowing the ground as is done for the shovel plow. A lateral plow, which is the name given to a plow used in irri- gation countries, is made by bolting together the beams of a right hand and a left hand plow. The shears are spread out, and rounded instead of being pointed. On top of the mold boards are riveted two other mold boards taken from other plows. Wide handle bars are bolted to the plow and well braced to the beams. Such a plow is draw r n by from 4 to 8 horses, according to the character of the soil and the depth of the ditch to be made. One operation of this plow turns two furrows, one to each side of the ditch, throwing the dirt high on the ground. A ditch with a clean bottom about 2 ft. wide is left. A tool of this kind should have extensive use in many sections of the country. The excavated earth could be afterwards leveled off with a two-horse grader or leveler. Ground can also be broken with a plow and then pushed to either side with an A-shaped drag, such as is used to clean paths through snow, made either of steel or timber. The bot- tom of the timber should be shod with iron. Ditching with Cable Operated Plows. Engineering News, Feb. ,3, 1916, gives the following: For excavating the smaller sizes of farm ditches, too small for the use of a floating dredge or a land dredge, a ditching plow 928 HANDBOOK OF EARTH EXCAVATION was invented about 40 years ago in western Indiana. It has a double moldboard and cuts a ditch about 4 ft. wide on top and 2 ft. deep, with a bottom width of less than 1 ft. To draw this plow, 80 oxen were used, making the ditch at one cut. This type of ditching machine finally developed into a standard outfit, con- Fig. 14. Plow for Ditching by Horse Traction. The plow, shown in raised position, is fitted with a side wing to form a berm along top of ditch. sisting of one plow and two capstans, using several thousand feet of steel cable with each rig. Work of Horse Capstan Plows. With this outfit the plow will cut a ditch 8 ft. wide on top, 18 in. on the bottom and Fig. 15. Capstan for Ditching by Horse Traction. The long horizontal pole is the sweep by which the horses turn the drum and the inclined timbers (one on each side) are anchors. about 3 ft. deep. It is drawn by two %-in. steel cables, one from each capstan, both being operated at the same time. It makes a ditch with one cut, either dry or under water, and places on sides of the ditch the earth excavated, pushing the earth DITCHES AND CANALS 929 back so as to leave a clean berm of 3 ft. The two capstans used to draw the plow are self-anchoring and have 14-in. vertical drums, each drum holding 1,000 ft. of cable. Four heavy horses are used on each capstan, working abreast and pulling at the end of a sweep that is attached direct to the drum. This sweep is usually about 24 ft. long, and the horses describe a circle nearly 50 ft. in diameter in order to wind in 3 or 4 ft. of cable. The work is so severe that relays of horses are used, and there are usually about 20 horses with each ditch- ing rig. These horse-driven ditching plows cut about 100 rods, or 1,650 ft. of ditch per day. In Wisconsin they frequently cut 50 miles Fig. 16. Caterpillar Tractor with Drum for Hauling the Ditch- ing Plow. When plowing, the tractor is stationary and is an- chored by the inclined spuds while the 60-hp. engine drives the drum for winding in the plow cable. of ditch in one season at a contract price of .from $1.25 to $2 per rod of ditch, depending upon the character of the soil. Ditches made in stony or timbered lands are the more ex- pensive. Power Operated Capstan Plows. A gasoline tractor supported by two long caterpillar wheels 30 in. wide carries a cable drum (Fig. 1C). Two anchor flukes, 2x10 ft. are placed near the front of the machine, one on each side. They are held at the proper angle by heavy chains attached to the frame of the tractor. These anchors hold the power capstan stationary when the plow is being pulled forward to cut the ditch. 030 HANDBOOK OF EARTH EXCAVATION The 1%-in. steel pulling cable is wound upon a large built-up cast-steel drum attached to the rear of the machine. This drum is 24 in. long, 16 in. in diameter, with flanges 36 in. in diameter. It is driven by two heavy link-belt chains from the main driving shaft of the tractor and is so back-geared that when the 60-hp. motor is running at its normal speed the drum winds in the pulling cable at a rate of 14 to 18 ft. per min., depending upon the amount of cable on the drum. The drum holds about 1,000 ft. of cable. When greater length is re- quired, on account of inaccessible grounds, etc., removable sec- tions of 500 or 600 ft. of cable are used to attain the desired length. It has been found that the pulling power is so much greater than that of the horse machines that the size of the plow can be increased. The new plows will cut ditches 2 ft. wide on the bot- tom and 3i ft. deep. They are made by the Glencoe Foundry and Machine Co., of Glencoe, Minn. Operating the Power Ditching Plow. The power capstan re- itains its original feature as a tractor and is used to haul the plow which weighs 4 tons when mounted on its removable trucks. It also hauls a wagon loaded with cable and supplies, and a boarding cabin mounted on wheels. It takes this outfit over ordinary country roads at the rate of about 2 mi. per hr. The machine weighs about 15 tons; but owing to its large bearing surface, it can travel under its own power over swamp lands too soft to support a team. It is driven- by a four-cylinder four- cycle gasoline engine of 60 hp., which also furnishes power to drive the winding drum. In operation the plow is left at the starting point of the ditch, the cable being attached to the beam of the plow. Then the power capstan moves ahead to some point on the line of the ditch to be cut, paying out the cable as it advances. When this point is reached, the traction gear is released and the wind- ing apparatus to the drum is thrown into gear. The anchors are released, allowing the points to drop to the ground. As the cable to the plow becomes taut, it draws the machine backward, causing the anchor flukes to enter the ground until the tractor with its capstan becomes firmly anchored. When all the cable is wound on the drum, or a change in the direction of the ditch is to be made, the winding gear is thrown out of action and the traction gear is thrown in. As the tractor then advances, it pays out the cable and withdraws the anchors, which are hooked up clear of the ground by power, and the ma- chine proceeds to a new point of setting, as determined by the foreman. DITCHES AND CANALS 931 The power capstan is operated by one man and a helper ; one man rides on the plow, and a tram with driver is used in hauling supplies to the camp and to the machine. A cook in the port- able cabin on wheels furnishes the food for the crew. A fore- man directs the movements of the whole outfit. Ditching with Cable Plow Operated from Barges. In ditch- ing land that is too soft to permit the operation of a caterpillar traction ditcher, or other traveling plants, either hand work, or the use of some sort of ditch plow operated from barges is the only alternative. According to A. M. Shaw, in Engineering EN6.NEW& "dnchorerqe for Swrhh Block Fig. 17. Method of Excavating Ditches by a Cable Operated Plow. News, Aug. 14, 1913, ditches in soft ground were excavated with an outfit consisting of the following: (1) two barges, 16 by 20 ft.; (2) a special compound-geared pulling engine, made by Clyde Iron Wks. ; (3) two lengths of %-in. steel cables, each 1,350 ft. long; (4) one length of light message cable; (5) one ditching plow. The engine has 7 by 10-in. cylinders and a ver- tical boiler (4 by 9 ft.) carrying 100 Ib. pressure. The total weight of boiler and engine is about 9 tons. The power plow consisted of a heavy log forming the main stem or keel, with a long steel " coulter " hinged to the under side. This " coulter " was made from a steel bar about % in. thick, 4 in. wide and 4 ft. long. The pulling cable was attached to the top, and another cable was also attached to the top of 932 HANDBOOK OF EARTH EXCAVATION the " coulter " and carried back by an adjustable hitch on the top of the center log. This latter cable was used for regulating the depth of cuts. From the front end of the log extended two heavy plank wings or mold board. The method of working was to excavate two main canals about 1,200 ft. apart, and to open the land between them by a series of connecting ditches (Fig. 17). On one canal a ditching plow was floated while on the other canal was a barge carrying the pulling engine. A steel cable ran from the plow to the forward drum of the engine, capable of exerting a 20,000-lb. pull. This cable pulled the ditching plow through the intervening 1,200 ft. of ground at a speed of about 3,000 ft. per hr. Another cable ran from the rear drum of the engine to a snatch block Lattra/DMies formed by Cable Experiments/ Tile Drains Lerees Fig. 18. Plan of a Canal and Ditch System for Drainage of a Tract of Swamp Land in Louisiana. on the farther bank of the lower canal, and thence to the rear of the plow. This latter drum (single-gear) exerted a pull of 8,000 Ib. to haul the plow back through the newly dug ditch to the canal, whence it was floated down to the next proposed ditch and the operation was repeated. It was not found practicable to cut a ditch more than about 30 in. deep with this device, and it lacked the adjustable fea- tures of a more elaborate ditching machine. It had the follow- ing advantages : ( 1 ) low first cost ; ( 2 ) economy of operations ; (3) simplicity; (4) easily transferred, as the plow is pulled into the canal and floated from one ditch to the next. One month, 156 quarter-mile ditches (or 39 miles) were cut with the plow, each ditch being gone over twice. The ditches averaged about 30 in. deep, 2 ft. wide at the bottom and 3 ft. wide on top. The cost of operating the plow, including repairs, DITCHES AND CANALS 933 fuel, etc., amounted to about 5 ct. per cu. yd. A crew of 10 to 12 men was required. Ditching by Explosives. Explosives if properly used will ex- cavate ditches and spread the material removed. The flow of water is depended on to clean out the bottom. Holes in stiff clay or hard pan should be 26 in. apart along the ditch, and in loose mucky soil 30 in. apart. They should be punched or bored to within 6 in. of the desired depth. In strongly sodded soil, cut with a spade along the side lines. All holes in the ditch should be blasted simultaneously with a battery if pos- sible, or placed closer together, 18 to 24 in. apart along the ditch, and exploded by concussion from the middle hole, that one being detonated by a fuse and cap. Tables I and II give the re- quired charges. Dynamite of 20% grade is ordmarily used, but in stiff tenacious soil 40% is better. When the material is soft at top and hard at bottom, use 40% dynamite in the bottom of the charge and 20% in the top. TABLE I OF CHARGES FOR DITCH BLASTING (USING BATTERY) Number of Distance rows of holes between required rows, in. 1 1 2 20 2 28 2 36 2 42 3 42 Required length of No. 6 Victor Elec- tric Fuses 4 ft. 6 ft. 6 to 8 ft. Distance apart in rows depends on nature of soil. TABLE II OF CHARGES FOR BLASTING DITCH (WITHOUT BATTERY) IB Distance between rows, in. 30 36 42 48 36 42 _,_.._ - 48 Distance apart in rows depends on nature of soil. For methods of blasting see Chapter V. Also see my " Hand- book of Rock Excavation." Top width of ditch in ft. Number of cartridges required for various depths 2% to 3 ft. 4 ft. 5 to 6 ft. 3 Vz 6 1 2 3 .8 1 2 3 10 1 2 3 12 1 2 3 14 1 2 3 16 1 2 3 Top width Approximate number of cartridges per hole required for various depths Number of rows of ditch 2V 2 to 3 ft. 4ft. 5ft. 6ft. required 6 1 2 2% 3 1 8 1 2 m 3 2 10 1 2 2% 3 2 12 1 2 2% 3 2 14 1 2 2% 3 2 16 1 2 m 3 3 18 1 2 2y 2 3 3 20 1 2 2Vz 3 3 934 HANDBOOK OF EARTH EXCAVATION Three Examples of Cost of Ditching by Dynamite. The fol- lowing work done at Chadhourne, N. C., for the Brett Engineering Co., as reported in Engineering and Contracting, May 8, 1012. Where the ground was comparatively free from stumps and roots holes were put down 18 in. apart, 3y 2 ft- deep, and 100 holes in all. Each hole was pointed 45 and loaded with one stick of Hercules 60% N. G. dynamite 1^x8 in., the center hole being primed with an extra stick and a double strength exploder. See Fig. 19. The result was a good ditch 7 ft. wide on top, 3 ft. on the bottom and 3 ft. deep and 150 ft. long. Costs of finishing and trimming according to specifications per running foot were: Explosives $11.35 Putting down holes 50 Finishing and trimming 4.50 Total cost of 150-ft. ditch $16.35 Total cost per running ft 0.109 The next ditch was shot at Sollo Swamp, where the ground was heavily matted with roots and stumps. The specifications here called for a ditch 14 ft. wide, 2^ ft. deep. A double row of holes were used, 100 in each row, 18 in. apart laterally, 4i ft. apart longitudinally, and 4 ft. deep. Both rows pointed 45 in the same direction. The middle holes were primed with an extra stick and a double strength exploder. Along the path of this ditch there were 35 stumps from 6 in to 3 ft. in diameter. The result was a clean ditch 12 to 14 ft. wide, 4 ft. deep and 150 ft. long. Explosives per running ft $0.100 Holes per running ft .007 Labor per running ft .030 Total cost per running ft $0.137 The next ditch was shot at Dunn Swamp, 150 ft. long in the muddiest and stickiest kind of ground. A double row of holes was used, 18 in. apart, 4i ft. laterally, 4 ft. deep, both rows pointed 45 in the same direction. Each hole was loaded with one stick of 60% dynamite and the middle hole of each row was primed with a double strength exploder. All the holes were well tamped. The result was a very clean ditch 14 ft. wide. 3i to 4 ft. deep and 150 ft. long. The total cost of this ditch was the same as the ditch shot at Sollo Swamp. A drainage ditch 2,600 ft. long, containing 1,732 cu. yd., was blasted out with 1,400 Ib. of 60% nitroglycerin dynamite. The method used was to prime the center holes in a line 300 to 500 ft. long with fuse and caps. According to B. L. Jenks in the DITCHES AND CANALS 935 DuPont Magazine for June, 1914, the land was very wet and it would have been impossible to use teams or a ditching machine. To have dug it by hand would probably have cost at least 33 ct. per cu. yd. The total cost by the dynamite method was $383 or 22.1 ct. per cu. yd., itemized as follows: Dynamite delivered Fig. 19. Arrangement of Holes for Excavating Ditches with Dynamite. on land, $278; labor putting down the holes and shooting, $104; fuse and caps, $1. Arthur E. Morgan, iu Engineering and Contracting, Feb. 1, 1911, gives the following about ditching in southeastern Mis- souri : One of the ditches examined, which had been constructed about a year, w r as 6 ft. wide on the bottom, 12 ft. wide on top, 3} ft. 936 HANDBOOK OF EARTH EXCAVATION . deep, and in good order. In digging it two i/-lb. sticks of 50% dynamite were placed 3 ft. apart in the ground and between 3 and 4 ft. deep. Two men construct a quarter of a mile of ditch in a day. At a cost of 15 ct. per pound for dynamite, and $20 per mile for placing the charges, the ditch had cost about 5 ct. per cu. yd. The ditch had been constructed through the woods without cutting down any of the trees, x and in some instances the fallen trunks were lying across the channel. Cost of Ditching with Dynamite in Georgia. Engineering and Contracting, July 9, 1919, gives the following: In connection with the anti-malarial preparations of the U. S. Public Health Service in the extra cantonment zone at Camp Wheeler, Ga., dynamite was used in the ditching work. The best results were obtained in mucky areas where the mud was so deep and soft that hand excavation became slow and difficult. In these cases, the use of dynamite proved satisfactory. In a report on the work by the U. S. Public Health Service the following comparative costs of ditching by hand labor and with dynamite are given. The figures are for two adjacent ditches in a large swamp in the extra cantonment zone. Ditch No. 60 was exca- vated with dynamite. This ditch was 2,802 ft. long, 12 ft. wide at the top and 4 ft. wide at the bottom, and averaged 5 ft. deep. The number of cubic yards of material removed was 4,151. Ditch No. 62 was excavated by laborers with picks and shovels. This ditch was 3,591 ft. long, 4 ft. wide and 3 ft. dx?ep. The yardage was 1,596. The cost of excavation in the case of ditch 60 in- cludes clearing out the ditch after it was dynamited. In the case of ditch 62 the cost of excavation includes the cost of a small quantity of dynamite used to facilitate the removal of large stumps. The costs of excavating each ditch, not including clear- ing, were as follows: Ditch 60. Ditch 62. Cubic yards 4,151 1,596 Labor 'cost $308.90 $671.75 Cost of material $1,265.10 $38.75 Cost of excavation $1,574.00 $710.50 Cost per cu. yd ' $0.39 $0.4o Man days at $3 103 224 Man days per cu. yd 0.024 0.140 Cubic yards per man day 41.66 7.14 The report states that it is probable that the cost of exca- vating ditch 60 by hand would have greatly exceeded 45 ct. a cu. yd., owing to the very difficult nature of the soil a mass of yielding mud, largely under water, in which it was almost im- possible to stand up. DITCHES AND CANALS 937 Blasting a Diteh in Quicksand and Clay. Engineering and Contracting, Nov. 21, U)17, gives the following: At one of the plants of the American Brick Co. a channel 530 ft. long, ex- tending through a tangle of underbrush, was successfully blasted. The soil is quicksand and clay. In blasting through the clay a hole was bored and cartridges pushed down with a stick, no tamping being necessary as the water filled the hole. The strip of quicksand measured about 35 ft. across. Tin tubes about ^ in. longer than a stick of dynamite were made. Cartridges were encased in the tin tubes and then pushed down into the quicksand. The cartridges were spaced about 2 ft. apart, both in the quicksand and in the clay. In one hole the charge consisted of iy 2 cartridges. The next hole contained 1 cartridge. And so on alternately down the line. The cartridges were put down to a depth of about 2i ft. The resulting shot gave a ditch about 3 ft. deep and 6 ft. wide. Ditch Excavation by Scrapers. When scrapers are used, with the exception of power scrapers, the ground must first be loos- ened by a plow. Two useful scrapers for small ditches are the Chicago Tongue Scraper and the Haslup Side Scraper. These are described and illustrated in Chapter IX. The rotary scraper can also be used for ditch excavation. This is a California invention. The scraper consists of a square pan that revolves about two fixed points in a frame made up of the bail and the handles, instead of being attached rigidly to the handles as is a drag scraper. The scraper is loaded in the usual way, and is dumped by the driver releasing a catch at the handle, thus allowing the movement of the scraper to dump itself. The other styles of scrapers can all be used either in exca- vating small or large ditches. However, the ground must be dry enough to allow horses to walk over it without becoming mired. Even if horses sink but a few inches .into the ground as they walk, their work is greatly retarded. Drag scrapers oper- ate poorly in very wet places. The suction of water on the bottom of the pans makes the work hard for the horses, but in dry material good work can be done, even when pulling up steep slopes. However, where the ditch is large enough, buck or Fresno scrapers can be used instead of drag scrapers; and with leads less than 60 ft. more economic work will be done. Ditches 6 to 8 ft. deep can readily be dug with buck scrapers. The mass of the yardage can be moved with them and then drag scrapers can be used to finish and dress up the work. For deep ditches and where the haul on the excavated 038 HANDBOOK OF EARTH EXCAVATION material is long, wheel scrapers will be found superior to either drags or buck scrapers. But the ditch must be wide enough for two teams to pass one another, or else the loaded scraper cannot get by the snatch team without delaying the work. Another kind of scraper that can be used to advantage in ditch construction is the Maney four-wheel scraper. This scraper has been described in Chapter IX. Power scrapers are also well adapted to ditch construction. Some form of a derrick car or movable derrick is used to oper- ate the scrapers. Descriptions of power scrapers are given in Chapter XIV. Cost of Excavating Ditches with Drag Scrapers. The out- put of scrapers at the experimental farm of the University of Minnesota is given in Engineering and Contracting, Oct. 21, 1008. The ditches were about 3 ft. deep and 4. 05 ft. wide. The scrapers were for the most part used for finishing up ditches excavated by elevating graders. On one ditch a drag scraper excavated at the rate of 43.5 cu. yd. per day, and on another at the rate of 41 cu. yd. per day. Each scraper required the services of 1 team and 1.5 men. The contractor acted as his own foreman handling the teams in gangs of 4 to scrapers. With wages for laborers and drivers at $2.00 per day, the cost of horses at $1.50 each, and allowing $3.00 per day for the serv- ices of a foreman, the cost per cu. yd. was 1C c't. On other ditches an experienced ditch man and team excavated at the rate of 65 cu. yd. per day, and a contractor with 2 teams and 3 men in a gang averaged 100 cu. yd. per gang per day, or 50 cu. yd. per scraper. See Chapter IX for other cost data. Cost of Main Canal for Payette-Boise (Idaho) Irrigation Project. Engineering and Contracting, Sept. 16, 1008, gives the following : Work under the contract was begun in Feb., 1006, and was completed in March, 1908. The total amount invested by the contractor and sub-contractors in plant was estimated to be $30,836, $28,230 of which was invested in teams and harness. In estimating interest charges the value of horses and harness was not included as they were considered in the cost records at current rate of wages for teams. During the first portion of the contract laborers worked 10 hr. per day, but during the latter portion an 8-hr. day. The following current wages were paid for an 8-hr, day: Superintendent, $125 per month; time-keeper, $100 per month; foreman, $3 to $4 per day; powder man, $3; drivers, $2.50; common labor, $2.25; stable boss, $67 per month. DITCHES AND CANALS 939 No materials -were furnished by the contractor, but consider- able supplies were needed in conjunction with the excavation of rock. Coal delivered on the work cost $9 per ton, black powder $2 per keg, giant powder $0.15 per lb., and lumber $22 per M. ft. B.M. The greater part of Class I excavation consisted of a stiff loam containing a considerable amount of clay with loose rocks of various sizes scattered through the mass. About one-half of this material was handled with Fresno scrapers, the remainder being handled in wheel and drag scrapers. Nearly all of the excavation was taken from the canal prism, there being very little taken from borrow pits. Class 2 excavation consisted of indurated material that could be plowed by 10 horses. This material was usually found be- neath Class 1 material, and after plowing consisted mainly of a mass of lumps of earth of various sizes. The lumps were broken by the passage of horses and scrapers over them, and were loaded and hauled by means of Fresno and wheel scrapers. Class 3 excavation consisted of indurated material that re- quired blasting before it could be removed, but that could be re- moved by the use of wheel scrapers. This material occurred lo- cally and was found usually near the grade plane of the canal. Class 4 excavation consisted of boulders less than one-half cubic yard in volume that would prevent plowing and the use of scrapers, and was scattered quite generally throughout Class 1 material. These boulders were usually removed by means of stone boats working in conjunction with wheel or Fresno scrapers. Class 5 excavation consisted of boulders exceeding one-half cubic yard in volume an:l solid rock, requiring blasting for re- moval. All drilling was performed by hand and a greater part of the blasting was done with black powder, though a small amount of giant powder was used. About two-thirds of this class of material was encountered in three of the heavier cuts, the remainder being scattered along the entire length of the canal. This material was moved by means of stone boats, but horse power derricks were used, together with the stone boats, in the deeper cuts with less satisfactory results. Table I gives the cost of the work. The following was the yardage of each class: Class 1 467,785 Class 2 . T 69,009 (Mass 3 20,30:1 Class 4 : 10,933 Class 5. . 85.828 Total cu. yd 653,858 940 HANDBOOK OF EARTH EXCAVATION There were 207,074 cu. yd. of " overhaul " that cost 2.3 ct. per. cu. yd. TABLE I. COST PER CU. YD. ON MAIN CANAL, PAYETTE-BOISE IRRIGATION PROJECT Class of Excavation (1) (2) (3) (4) (5) 001 002 004 004 008 003 006 008 009 .020 Repairs 006 .011 .014 .017 042 001 002 004 003 007 014 025 031 033 092 001 001 002 001 002 019 056 058 085 Drilling by hand 057 021 209 098 029 225 Loading, hauling and spreading . . .089 .006 .164 016 .255 021 .294 032 .507 Water, original cost, and hauling. .001 143 .003 291 .001 561 .001 538 .004 1 133 .007 .016 .022 .035 .046 Total cost $.150 $.307 $.583 $.573 $1.175 Cost of Canal Excavation for TTncompahgre Irrigation Proj= ect, Colorado. Engineering and Contracting, Nov. 18, 1908, gives the following: The work covered 4,400 lin. ft. of the South Canal, which was begun in June, 1907, and completed in May, 1908, at a total cost of $22,932. The canal has a bottom width of 40 ft., side slopes of 2 to 1, water depth of 8.3 ft., and a discharge of 1,175 second-feet. Class 1 excavation contained all material that could be plowed by an average six-horse team, each animal weighing not less than 1,400 lb., attached to a suitable breaking plow, and also all isolated masses of rock not exceeding y 2 cu. yd. in volume. Class 2 excavation consisted of material originally of the na- ture of Class 1, but so saturated with water as to render the use of teams in the ordinary manner impossible. Class 3 exca- vation consisted of indurated material of all kinds that could not be plowed as Class 1, or that required loosening with powder before being removed in scrapers, and also all loose material in which large rocks occurred to such an extent as to prevent the use of plows and scrapers, excluding masses exceeding 1 cu. yd. in volume. Class 4 excavation consisted of rock in masses greater than 1 cu. yd. in volume and requiring drilling and blasting before removal. The limit of free haul was 300 ft. About 73% of the material was removed with drag, Fresno and wheel scrapers, about 27% with a slip and chain, and the re- mainder with shovels and wheelbarrows, DITCHES AND CANALS 941 The weather conditions were good for the performance of work throughout the continuance of the contract, and the management was good with the exception of insufficiency in the number of foremen employed. Labor was scarce and high. On the excavation laborers were pa4d at the rate of from $2.25 to $2.50 per day; foremen at the rate of $3 per day and the superintendent at the rate of $122.50 per month. The yardage was as follows: Class 1 24,194 Class 2 15,054 Class 3 .' 17,058 Class 4 100 Total cu. yd 56,406 There were 6,600 cu. yd. of " overhaul " that cost 1.7 ct. per cu. yd. The unit costs of the different classes of work are given in Table I. TABLE I. COSTS PER CU. YD. OF EXCAVATION OF IRRIGATION CANAL, UNCOMPAHGRE PROJECT, COLORADO Class 1 Class 2 Class 3 Class 4 $0 002 $0 005 $0 003 $0 006 Plant depreciation . . 0.002 0.006 0.004 0.008 028 070 048 062 Labor 197 503 0.339 439 002 001 260 Contractor's total cost . . .. $0.229 $0.586 $0.395 $0.775 U. S. engineering .. $0.013 $0.009 $0.012 $0.001 Total cost $0.242 $0.595 $0.407 $0.776 . Cost of Huntley Irrigation Canal. Engineering and Con- tracting, Jan. 20, 1909, gives the following: Division 1 of the Main Canal of the Huntley Project contains a section of about 390 ft. in length, having a depth of 17 ft., a base of 14.5 ft. and side slopes of ^ on 1. In addition to the material covered in this prism, there were about 2,000 cu. yd. of material excavated above the general level on one side of the canal extending to the top of a cliff along the base of which the canal takes its course. The work of excavation of this sec- tion of the canal was done by contract, and below is vgiven a summary of the cost of the work to the contractor. The excavation was divided into the three following classes: Class 1, earth or material that could be plowed and handled with scrapers; Class 2, loose rock varying in volume from 2 to 20 i-u. ft. ; Class 3, solid rock or material not included in either 942 HANDBOOK OF EARTH EXCAVATION of the foregoing classes. Most of the material consisted of a bluish gray sandstone of medium hardness and was paid for under Class 3. The material excavated from the main prism of the canal was loosened by blasting with 40% gelatine dynamite. All drilling for blasting was done by hand. About two-thirds of the ma- terial was removed in small cars of ^ cu. yd. capacity. The finer portions of the remainder were loaded by hand into one- horse dump carts and hauled a distance of about 200 ft.; and the larger pieces were rolled onto sheet steel sleds, which were unloaded by driving the sleds over the side of a near-by dump, causing the rock to roll off the sled. The material taken from the cliff above the canal prism was handled in the same manner as the coarser portions from the canal prism. The principal superintendent was paid at the rate of $6.67 per 8-hr, day; the assistant superintendent, $5.75; the foreman, $3.25; laborers, from $2 to $2.40; single horse and cait, $1 ; team an 1 car, $2; team and driver, $4; blacksmith, $2.80. In Table I the cost of the principal and assistant superin- tendent and the foreman has been charged under Executive, the cost of all other work under Labor, and the cost of coal, oil and blasting material under Supplies. TABLE I. COST PER CU. YD. Class 1 Class 2 Class 3 391 cu. yd. 1,507 cu. yd. 6,427 cu. yd. Executive ~ $0.009 $0.139 $0.127 Labor 0.094 0.646 0905 Supplies 0.103 Total $0.103 $0.785 $1.135 Cost of Klamath Irrigation Canal. Engineering and Contract- ing, May 19, 1909, gives the following: About 12.3 miles of South Branch Canal on Klamath Project were constructed under two contracts during the season of 1908 and part of 1909. The upper end of the canal is about 8 miles from Klamath Falls, and the whole of the work was divided into eight schedules averaging about 1} miles in length. Sched- ules 1, 2 and 3 were constructed under contract, the greater part of the work being done from May to December, 1908. The excavation of about 8,000 cu. yd. on schedule 1 was delayed until the spring of 1909 and was finished in March. On schedules 1 and 3 the bottom width is from 15 to 18 ft. and the slopes are ]) to 1. On schedule 2 the canal is built entirely in em- bankment with a bottom width of 3.8 ft. and on side slope of 1 to 1. On this schedule the material for the outer triangles DITCHES AND CANALS 943 o I i s P3 CO O 03 -O 1 O 5 003 > Ol 00 O O rH *?f CO (M >O T-l >o o T-I o-i Tf< ,H . ,_( ,-1 o ,-< >o ooooo -oooo iHOOtH - OOO - > OOO01M rH O-lft r-t )Cq * iH rH OO r-i >000 -0000 is : a''' ) O O CO irt t-- rH < ^ z 5 M Mo5*5o c^^oo.o.oo. ooqoooo.o_oc> i-Icoo" O" o" w O S ^ A HSE2 w "S21 r .?>/. *tj( -Jif S.| t TS : : ^( j_ 1 (JJ ' u * S: Su .2 3S,:S" S S H I S he a i I a Si 044 HANDBOOK OF KA&TH EXCAVATION of the canal banks, amounting to about 40% of the total, was deposited in 12-in. layers in the ordinary manner of building embankments, but the other 60% of the material was deposited in 6-in. layers, sprinkled, and rolled. Schedules 4, 5, 6, 7 and 8 were constructed under formal contract and informal specifica- tions, the greater part of the work being done from August to December, 11)08. A' small amount of work on schedules 4 and 8 was done in the winter of 1908-9, and finished in March, 1909. For all of schedules 4, 5, 6. 7 and 8 the bottom width of canal is 11.5 ft. and the side slopes 1% to 1. On all schedules most of the material excavated was earth that could be plowed by six-horse teams, and in general no bad con- ditions were encountered. A small amount of indurated ma- terial that required blasting before scrapers could be used was encountered, but no separate estimate of the cost of excavating this material was kept. The per cent of this material in terms of the whole amount of excavation on the several schedules is, however, tabulated with the unit costs. On the first contract, covering schedules 1, 2 and 3, an estimate of interest on investment is made at 6% per annum on the es- timated value of animals and equipment. For the second con- tract, covering the other schedules, no estimate of interest on investment has been made. For both contracts an estimate of depreciation of equipment has been made at 2% per month on the total value thereof. The weather and labor conditions were generally good under both contracts. The wages for common labor were $2 per day, and the cost of animals, including de- preciation, was estimated at $1 per day each. Table I gives the unit costs of the work, including cost to the contractors and the engineering expenses of the United States, together with other useful information relating to the work. Using an Engine Instead of a Snatch Team to Load Scrapers. In the construction of a canal in connection with an irrigation scheme, part of the material was removed by means of wheel scrapers. The canal was to be 40 ft. wide at the bottom, with 1 to 1 side slopes, varying in depth up to 42 ft. The canal was dug mostly in clay, but there was some rock. The spoil was placed alongside of the cutting, leaving a berm 30 ft. wide. Part of the material was removed by scrapers of about 16 cu. ft. capacity drawn by two horses. An ordinary winding engine was used instead of an extra team of horses for loading the scrapers. The engine was placed on the bank, close to the edge of the excavation, so that the %-in. wire hauling rope might pass either way about 300 to 400 ft. along the canal. The hauling rope was attached and detached at the pole of the scraper by a la- DITCHKS AND CANALS 045 borer; a pony driven by another attendant was used to drag the rope from place to place for this laborer. In order to prevent the scraper cutting too deeply and to prevent undue pressure on the necks of the horses a gage wheel was used under the rear end of the pole. Cost of Canal, Milk River Project. A. E. Bechtel, in Engi- neering and Contracting, Sept. 20, 1916, gives the following: The earth work of the second unit of the Dodson North Canal, Milk River Irrigation Project, near the town of Malta, Mont., was begun on Sept. 1, 1913, and completed on Sept. 1, 1914, by contract. There were 230,000 cu. yd. of excavation in canals and 70,000 cu. yd. in waste water ditches. The canals were from 5 to 10 ft. bottoms with a slope of 2 to 1, and contained from 100 cu. yd. to 1,300 cu. yd. to the station of 100 ft., averaging about 400. Approximately 20,000 cu. yd. was wet and 30,000 cu. yd. was hillside work. The waste water ditches had from 3-ft. to 20-ft. bottoms (mostly 3 ft.) with a slope of 1^ to 1, and averaged about 100 cu. yd. per station; 10,000 cu. yd. was wet excavation. About 35,000 cu. yd. were cast into the canal banks with an Austin reversible elevating grader pulled by a 30-60 hp. Pioneer gas tractor, and 25,000 cu. yd. of the excavation of the waste water ditches were cast out with an Austin senior elevating grader. These machines were operated two and three shifts during the fall of 1913 and one shift during 1914. The remainder of the work, 240,000 cu. yd., was done with 5-ft. fresnoes, excepting the finishing of the waste water ditches, which was done with drag scrapers, and about 5,000 cu. yd. of over-haul done with wheelers. About 60,000 cu. yd. of the work was sub-contracted but the costs here are the costs to the sub- contractors. The material excavated in the canals and laterals, other than that designated as wet, was average clay soil with more or less gumbo. The waste water ditches were mostly gumbo and baked so hard that in excavating it with a* grader, it was hard to keep the plow in the ground. The cost, to the contractor, of 134,517 cu. yd. excavated in 1913 was 21.3 ct. per cu. yd., a typical section being No. 1 which contained 13,192 cu. yd. excavated by fresnoes at a cost per cu. yd. of: Ct. Labor 8.2 Teams 6.3 Superintendence 2.4 Equipment 0.9 General expense 2.7 Total per cu. yd 20.5 946 HANDBOOK: OF EARTH EXCAVATION The cost of excavating 116,124 cu. yd. in 1914 was as fol- lows: Team Work Superintendence $0.0100 Foreman 0.0114 Plow 0.0160 Fresno 0.0771 Blacksmith 0.0012 Fence and grubbing 0.0005 Finishing . 0.0028 Equipment, hardware and tools 0.0161 General expense 0.0038 Labor, erecting, moving and maintaining camp.. 0.0014 Cook 0.0044 Labor, hauling camp and table supplies 0.0020 Labor, maintaining stable 0.0036 Total, teams, 93,949 cu. yd $0.1503 Machine Work Superintendence $0.0024 Labor . 0.0302 Gas and oil 0.0297 Repairs 0.0188 Equipment, hardware and tools 0.0683 Total machine, 22,175 cu. yd $0.1494 Total Machine and teams, 116,124 cu. yd... 0.1501 The machine consisted of a Reversible Austin Elevating Grader and Pioneer Tractor. Work on 48 structures (spillways, culverts, etc.) involving 17,- 644 cu. yd. of excavation and 8,115 cu. yd. of backfill, was done at an average cost of 61 ct. per cu. yd. of excavation, distributed as follows : Ct. Foreman 2.0 Excavation ' 35.0 Backfill 7.0 Total field cost 44.0 General supervision 5.0 Equipment -5-0 General expense 7.0 Total 61 - The material was clay. In small jobs, where the clay was hard, the excavation usually cost about as follows, for a spillway excavation of 54 cu. yd. with no backfill: Foreman '. $0.17 Excavation 1.24 General supervision 0.13 Equipment 0.19 General expense 0.19 Total per cu. yd $1.92 DITCHES AND CANALS 947 In excavating for culverts in average clay, all the excavation being subsequently backfilled, the following was a typical cost. Foreman $0.03 Excavation 0.43 Backfill 0.12 General supervision 0.05 Equipment 0.07 General expense 0.08 Total per cu. yd $0.78 Use of Elevating Graders for Ditching. Elevating graders can be used for ditch construction, but in very wet ground they are barred as the horse or engine used to propel them would be mired. For ditch work, especially where there is tough grass and small roots, a disc plow on a grader will do more efficient work than the ordinary turning plow. The disc plow also throws the material onto the elevating belt better. For such work the elevator should be extended to 30 ft. if the ditch is a wide one. It is in this class of work, where the material is thrown onto the banks, that an elevating grader reaches its greatest capacity. One objection to an elevating grader in ditch construction is that the machine will not finish off the slopes or the bottom of the trench, as the plow runs irregularly. But the work can be done very cheaply, and the ditch can be finished off at small cost with road machines and scrapers. For narrow ditches the machine is not very -well adapted, a width of 8 ft. at the bottom being necessary, but in wide ditches it will do excellent work, and the cost of dressing up the ditch is proportionately smaller. Fig. 20 (1-4) indicates the types of ditches that may be ex- cavated with an elevating grader, and the methods of attacking the work. Fig. 20-1 shows a ditch 2 ft. deep and 4 ft. wide on the bottom with 1^ to 1 slopes. In cutting a ditch of this size a 15-ft. elevator is used. The earth is thrown from the left side of the cut to the right bank, and in returning it is thrown in the opposite direction. This method is known as " cross-firing." This is about the minimum size of ditch which can be practically excavated in this manner. Fig. 20-2 shows a ditch which may be excavated by the use of two sizes of elevators. The first 2 ft. in depth is excavated with a 15-ft. elevator starting the cut along the outside of the ditch and working toward the center. The last 2 ft. is then excavated by an 18-ft. elevator, leaving a berm of about 2 ft. on each side. Fig. 20-3 represents a ditch which is deeper than can be handled 948 HANDBOOK OF EARTH EXCAVATION ordinarily with an elevating grader. By using the following method, however, such a ditch can be successfully handled. Using a 21 -ft. elevator the top 2 ft, are first excavated, and to a width 6 ft. beyond the required ditch line. This extra section taken out will be refilled from the bottom cut. The second CngContg Fig. 20. Sizes of Ditch That Can Be Dug with Elevating Graders. operation is to excavate the next 3 ft. in depth. This section is narrowed down to 23 ft. on top, this being the width of the re- quired section of ditch as shown by this drawing. The first two operations will, in this case, take out 5 ft. in depth, using the method of working from the outer edges of the ditch" toward the center. The third operation consists of cross-firing and depositing DITCHES AND CANALS 949 the earth from the bottom of the cut into the sections lettered a in the figure. Fig. 20-4 shows a side hill cut. This ditch cannot be so eco' nomically excavated as the others since the spoil bank IS limited to one side of the cut and the machine operates in one direction only, making the return trip empty. The downhill slope is usually plowed as indicated in the figure to prevent sliding of the embankment and to prevent the larger chunks of earth from rolling down hill. For a ditch of the dimen- sions indicated an 18-ft. elevator should be used. The outputs of elevating graders excavating ditches for the drainage system of the Minnesota University experimental farm are given in Engineering and Contracting, Oct. 21, 1908. The ditches were excavated an average width of about 3 ft. at the bottom and a depth of 4.65 ft. On one ditch a grader removed 2,040 cu. yd. at the rate of 450 cu. yd. per day of 10 hr., and on another ditch it removed 4,000 cu. yd. at the rate of 1,000 cu. yd. per day. Sixteen horses and 4 men were required for the operation of a machine. If the rate of pay of men was $2 per day and of horses $1.50 per day each, the cost was 3.2 to 7.1 ct. per cu. yd. In finishing up these ditches drag scrapers were used. See Chapter IX for other data on elevating grader work. Ditch Excavation with a Grab-Bucket Excavator. Engineer- ing and Contracting, Oct. 13, 1909, describes work done in the Modesto and Turlock districts along the San Joaquin river in California. An irrigation canal about 20 ft. wide on the sur- face, and G ft. deep with steep sides was dug. It was anticipated that the sides would cave, leaving a canal about 3y 3 ft. deep. Most of the soil encountered was sandy, hardpan lying under the sand at varying depths. The dredge cost $5,000. It is of the type which moves in the axial line of the canal to be dug and recedes from the breast of the canal as it is excavated. It differs from the side line dredge in that its boom motion is produced by a turntable. The dredge machinery is mounted on a skid platform 18 by 30 ft., \vhich rests on several movable wooden rollers run on planks placed on the ground. As the canal is excavated the dredge is moved 3 to 5 ft. at a time by means of a steel cable anchored to a " dead man " several hundred feet ahead of the dredge, and wound on a drum, which is power-driven by a worm gear from the engine. The tower or A-frame which supports the 40-ft. boom is 20 ft. high. This boom supports the cable sheaves for the bucket and inclines about 45, but has no vertical motion, al- though it may be swung about 180 horizontally by. a cable-pro- pelled turntable located at the front of the dredge under the 950 HANDBOOK OF EARTH EXCAVATION tower. The bucket is a 1-cu. yd. capacity clam-shell type, weigh- ing about 2,800 Ib. The machine is controlled by means of three levers and two foot brakes, mounted on a platform on the A- frame. "Power is furnished by a 25-hp. single-cylinder gasoline engine, which drives a series of combination gear and friction brake drums controlling the motion of the excavating bucket. The following was the operating cost per month: Crew: Foreman $ 95.00 Assistant foreman 85.00 Swamper 50.00 Swamper, one-half month 25.00 Man and team (half time) 50.00 Total crew $305.00 >.! i H: . Supplies : 400 ft. %-in. hoisting cable $50.40 6% gals, gasoline 1.60 3 gals, lubricating oil <>-75 5 Ib. Hecla compound 1.25 595 gals, distillate, at 7.5 ct. per gal 44.62 1 cylinder cup 3.00 Rollers 21.00 Large intermediate gear 14.00 172 Ib. dynamite, at 16 ct. per Ib 27.52 1,000 ft. fuse ~ 7.50 2 boxes caps !"" Depreciation of dredge ($5,000) 40.00 Total supplies and depreciation $216.24 Total cost of excavation per mo $521.24 Total cubic yards excavated 14,941 Cost per cubic yard excavated $0.0<>5 Operation cost per hour (based on 255 hours) $2.05 Operation cost per hour (based on 200 hours) $2.61 Cubic yards excavated per hour (based on 255 hpurs) 58.6 Cubic yards excavated per hour (based on 200 hours) 74.7 An actual cost of 3.5 ct. per cu. yd. of excavation is very good under ordinary conditions, and especially low considering the fact that this cost includes excavation of hardpan and that the proportion of time lost in making repairs was abnormal. The customary contract price for moving surface earth with teams in this district has been about 8 ct. per cu. yd. where no hard- pan is encountered, and the excavation of hardpan has cost as high as 50 ct. per cu. yd. Comparing this with the above figure of 3.5 ct. gives a decided advantage in favor of dredge operation where practicable. The output was 747 cu. yd. per 10-hr, day for 20 days per month. Cost of Excavating Drainage Ditch With a Dragline Exca- vator. Ray S. Owen, in Engineering and Contracting, Mar. 11, DITCHES AND CANALS 951 1914, gives the following data regarding the cost of excavating drainage ditches in Rock County, Wis. The machine used was a dragline dredge with steam power, running on a track laid by hand and propelled by pulling on a dead man with the hoisting drum. The operating crew consisted of 1 runner, 1 fireman, 2 trackmen and 1 teamster. The ditches are in a hay meadow, the soil being about 2 ft. of muck underlain by sand. Ihe ditches averaged 5 ft. deep with 1% to 1 slope, the main ditch, 2.60 miles in length, having a 6-ft. bottom with 21 -ft. top and the lateral 1.36 miles in length, having a 4-ft. bottom with 19-ft. top. The total excavation com- puted for the ditch was 53,019 cu. yd. The soil caved very badly and a large amount of excess material had to be excavated to get the specified prism clear of dirt. The amount of earth actually moved was about 75,000 cu. yd. The two ditches are not connected but empty into Sugar River at points about one-quarter mile apart. This arrangement ne- cessitated a tear down and move of about three miles from the end of one ditch, after it was completed, to the other ditch, and a set up. The costs given include freight on machine from Madison, Wis., to Sterling, 111., the operation, moving, repair, etc., of the machine during the work, and the tearing down and delivery of the machine on board cars at Sterling, which is about 8 miles from the job. The rent of 2 ct. a yd. included the furnishing, by the owner of the dredge, of sheaves and cable, which was a large item as the sand wore them out very rapidly. The cost of coal, teaming and moving is rather large, because of very bad roads when the outfit was moved out in the spring and the deep sand through which the coal was hauled during the summer. The unit prices are given for the contract yardage and for the actual yardage. Contract Actual yardage yardage Rent of dredge $0.020' $0.014 Labor 054 0.038 Coal 0.009 . 0.006 Express and freight 0.003 0.002 Bond and liability insurance 0.002 0.002 Livery and carfare 0.002 0.001 Oil 0.001 0.000 Teaming and moving 0.011 0.008 Tools, supplies, repairs, la^ber 0.003 0.002 Miscellaneous 0.001 0.001 Total cost per cu. yd $0.106 $0.074 Electric Dragline Excavators on Drainage Work. Electrical World, Oct. 28, 1916, gives data for drainage work on the Boise 052 HANDBOOK OF EARTH EXCAVATION Project of the U. S. Reclamation Service in the vicinity of Cald- well and Nampo, Idaho. Four excavators of the same type and capacity, having cater- pillar traction, 50-ft. booms, 9.5-ft. swing circles and 1.25-cu. yd. buckets are used. They are designed to operate on 440-volt, three-phase, 60-cycle, alternating-current supply. The caterpillar drive and the drag drums of the excavators are driven by direct geared 80-hp. motors controlled by a drum-type controller pro- vided with resistance, switchboard and circuit breakers. The swing machinery is operated by a 40-hp. motor provided with a drum-type controller for quick acceleration, designed to make it possible to reverse at full speed. The operating crew consists of two men for each excavator the operator and an oiler. The total drainage results accomplished on the Boise Project with the electric excavators to June 1, 1916, consists of the re- moval of 3,762,350 cu. yd. of material in approximately 93 miles of open ditches. The ditch sections vary from 10-ft. base 2 to 1 slopes, to a 5-ft. base 1.5 to 1 slopes, and the average cut ap- proximates 10 ft. At the field camp headquarters a substation is located which transforms the current to 4,000 volts. The transmission lines erected for the drainage construction carry 4,000 volts and are built and rebuilt as needed in the construction of the various drains. In the building of these lines, 30-ft. poles are generally used and No. 4 bare copper conductor. The connection from the transmission line to the other transformers which are carried on the dredges consists of No. 6 B & S gage triple conductor armored cable, and connection is made from the three wires of this cable to the transmission lines by hook switch terminals fastened on the ends of light 25-ft. poles. The connection is transferred from pole to pole as the construction proceeds, and the 300-ft. length of cable used allows the passing of obstruc- tions. The average energy used is approximately 0.88 kw.-hr. per cu. yd. of material excavated, varying with the material exca- vated, being as -low as 0.39 kw.-hr. in light sandy loam including all line and transformer losses. The use of power has been very convenient around the head- quarters camp, where a machine shop is electrically operated to handle repairs and also for use in pumping water in the con- struction of culverts. Each excavator is lighted by two inclosed- type flaming arc lamps. The approximate cost of excavation to date has been as fol- lows: DITCHES AND CANALS 953 Labor cost $0.023 Electrical energy (at 1 ct. per kilowatt-hour) and supplies 0.019 Installing transmission and telephone lines and sub- stations, including cost of materials 0.013 Total per cu. yd $0.055 This is exclusive of depreciation and general expenses. Drainage Canals Built by Dredge and Dragline. Engineering News, Feb. 20, 1913, gives the following: Over-use of water for irrigation having turned productive farms, on the Yakima Indian Reservation, Washington, into swamps and barren alkali flats, a drainage system was constructed by day labor by the U. S. Indian Service. The following are the detailed costs and construction data of the three machines used: Marion Dredge 1-yd. dipper dredge, 40-ft. boom. Limit of dump above water 15 to 18 ft. Limit of digging below water, 12 ft. Center of hull to center of dump, 35 to 40 ft. Size of hull, 60 x 18 x 5y 2 ft. About 24,000 ft. B. M. lumber required in construction of hull. Cost of machinery f.o.b. Marion, Ohio, $5,000. Cost complete with hull in working order about 8 miles haul from the railroad (exclusive of freight charges on machinery from Marion, Ohio, to Toppenish, Wash.), $10,034. Started to excavate, Nov. 17, 1910, and worked steadily till Mar. 13, 1912, usually excavating in soft material with gravel subsoil and occasional streaks of hardpan. Results: Total cu. yd. excavated i 502,911 Total in. ft. of canal 57,944 Total 8-hr, shifts operating 823 Cost per cu. yd.: Field supervision, including clerical $0.005 Labor operation 0.037 Hardware, tools, etc 0.002 Repairs, shopwork, etc ; 0.004 Camp maintenance * 00} Coal, $4.85 per ton delivered 0.016 Cable 0.005 Oil, waste and carbide for lights 0.003 Total per cu. yd $0.074 No depreciation charges have been added, but it is believed that from 1 to iy 2 c. per cu. yd. would cover this item. Dragline This machine was constructed by the Washington Iron Works, of Seattle, Wash. It had a 50-ft. boom, with 1 yd. Channon bucket, operated by a 7 x 10^-in. double engine. The machine was mounted on skids and hauled back by an independent 954 HANDBOOK OF EARTH EXCAVATION engine mounted on the rear. It was started in September, 1910, and finished on expiration of lease, Apr. 15, 1912. The material excavated comprised volcanic ash with occasional streaks of hardpan that required blasting, underlaid with loose gravel. Total cu. yd. excavated 539,235 Total lin. ft. 9f canal 68,590 Total 8-hr, shifts operating 917 Field supervision, including clerical $0.006 Labor operation, including $225 rent per mo 0.060 Hardware, tools, etc 0.003 Repairs and shopwork 0.011 Camp maintenance 0.003 Coal, cable, oil, waste, carbide for lights, etc 0.026 Total per cu. yd $0.109 Due to the layout of the canals, this machine moved empty about 2% miles, which expense is included in the above costs. Lidgerwood Class B. Dragline Excavator This machine com- plete for operation on the ground about two miles haul from railroad, exclusive of railroad transportation from Chicago, cost $11,555. The material excavated comprised volcanic ash soil with oc- casional streaks of hardpan, underlain with loose gravel. The machine started to operate Oct. 1, 1910, and the data are given to June 20, 1912. Total cu. yd. excavated Total lin. ft. of canal 92,305 Total 8-hr, shifts operated 1,024 Field supervision and clerical $0.005 Labor operation 0.035 Hardware, tools, etc 0.004 Repairs and shopAvork 0.013 Camp maintenance 0.002 Coal, cable, oil waste, carbide for lights, etc 0.023 Total per cu. yd '. $0.082 No depreciation has been charged in the above, but it is be- lieved that about iy 2 ct. per cu. yd. should cover this item. This machine moved empty, a total distance of about 18 miles, which expense is included in the above costs. It may be of interest to note that the total amount disbursed, including engineering, structures, clearing, fence moving and in- ventory, which covers all depreciation, added to the excavation, shows a cost of about 12 ct. per cu. yd. when applied wholly to to the excavation. Floating Dredges for Ditching. The methods and costs of floating dredge operation will not be treated at length here as a full discussion of this subject is given in Chapter XV. There DITCHES AND CANALS 955 are a number of companies manufacturing dredges especially for ditch work. Almost all dredges -used for this type of construc- tion are either grab-bucket or dipper dredges, the latter being generally used. While dipper dredges do not make as neat a ditch or one to as exact grades and slopes as many of the other types of machines, they have gained favor because they can be worked under all kinds of adverse conditions and in any sort of material, not ex- cepting blasted rock. In many sections of the country stumps and roots, as well as buried logs, impede the work of the machines. Any contractor who has worked through such ground knows what difficulties he has had to overcome. Sunken logs are a prolific source of trouble, especially when they are of any length, and* more than half of the log protrudes under the banks of the ditch. A dipper dredge has been the only successful machine for such work. A finished, well-sloped ditch, with a true grade and solid bot- tom without holes in it, and spoil banks in good shape with a sufficient berm between them and the ditch to prevent the ma- terial from sloughing back into it, is much to be desired, to secure cheapness of maintenance and to make the ditch do efficiently the work for which it is designed. A very important feature of dredges is the spuds. A dredge is, as a rule, either equipped with vertical or bank spuds, or both. These are necessary to balance the boat and hold it to its work, especially in digging hard materials or in handling large logs or stumps. They also prevent the boat from being wrecked or sunk. They must be adjustable in case of sudden high water and also for receding water. If they cannot be adjusted in a reasonable length of time, delays occur that are expensive. Spe- cial attention should always be paid to the spuds both in pur- chasing a dredge and in operating it. Clam-shell or orange-peel bucket dredges are used to a large extent in ditch construction. In both styles of these buckets dif- ferent types are made for soft and hard digging. In both the clam-shell and orange-peel buckets, makers build a type to grapple boulders and stumps. Ladder Dredge Used in Excavating a Small Canal. A. M. Shaw, in Engineering News, Aug. 14, 1913, gives a description of machines used in excavating ditches and small canals in Louisiana, and states that ladder dredges of the Menge type have been used on work of this kind. The manufacturers of this dredge state that in open swampy prairie land a ladder dredge can do twice as much work as where the soil contains much clay, as the clay sticks to the bucket and will not dump. Where stumps 950 HANDBOOK OF EARTH EXCAVATION or cypress roots exist in considerable numbers trouble is ex- perienced. A dredge used near New Orleans, with a hull 22 by GO ft. and the ladder swinging to either side, cut a canal 35 ft. wide. The distance from center line of the boat to end of the discharge apron was 40 ft., and the velocity of discharge was usually great enough to cast the material about 10 ft. further. The ladder had 32 buckets of about 6 cu. ft. capacity each. The boiler was 50 hp. and the engine had two Ilxl6-in. cylinders. The cost of the dredge was about $10,000. The average monthly output of the machine was 24,000 cu. yd. The coal consumption was 1.5 to 2 tons per shift of 10 hr. The cost of operating the machine on a single shift was about $650 a month, giving an operating cost of about 2.8 ct. per cu. yd. Cutting 1 to 1 Slopes With a Dipper Dredge. Engineering News, Oct. 19, 1916, gives an account of drainage work on the Little River Drainage District in Missouri. The ditch system involves 625 miles of dredged channels containing 34,250,000 cu. yd. of excavation. The ditches range in size from 4 ft. bottom width and 8 ft. depth, to 123 ft. bottom width and 12 ft. depth. All work is done by floating dipper dredges, with bank spuds for the smaller, and bank or bottom spuds for the larger ma- chines. The laterals are cut mainly by dredges with 1-yd. buckets. For the main ditches a 1-yd. dredge makes two pilot cuts 6 ft. deep, one on each side. These are about 22 ft. wide on top and 12 ft. on the bottom, with the 1 to 1 slope on the outer side. A larger dredge first extends each pilot cut to the full depth, and then takes out the center. In this way five cuts are made for the complete section. On the ditch with 123 ft. bottom width a dredge with a 4-yd. dipper has made a record of 83,278 cu. yd. in 26 working days. The contract states that the completion of the work within the time is of special importance. With this in view it is specified that any contractor, before beginning the erection of a dredge, must obtain the engineer's approval of its size and capacity. This is required in order to prevent the use of dredges of insuffi- cient capacity to make the desired progress. The specifications provide that the work is to be staked out in advance by the engineer, to show the exact location and width of right of way, the ditch, the berm, and the levees. The depth of cut for a ditch and the height of fill for a levee are to be marked on the stakes. The cutting of small ditches to greater widths than those speci- fied (in order to admit floating dredges) may be done under cer- tain conditions. The specifications provide that when the prism DITCHES AND CANALS 057 is not of sufficient width to accommodate the dredge installed, the necessary width shall be obtained when possible by flattening the side slopes. Increasing the prism of ditches is permitted, subject to the approval of the engineer, but the increased prism must conform to the specified section (except in area), and payment is made only for material within this section. In moving dredges from one piece of work to another it may be necessary for one contractor to pass over work which has been let to another contractor but has not been constructed. In such cases the former makes a cut sufficient for the passage of his dredge and is paid for this on the basis of volume actually removed at a price y a -ct. per cu. yd. below that of the contract price of the other contractor. The y 2 -ct. deduction is paid as compensation to the latter. Dredging Ditches with 1 to 1 Slopes. A specially interesting feature of the work is that by the specifications the dredges are required to finish the cuts with 1 to 1 slopes. On ditches of this kind the usual practice is to excavate them to practically a U-shape, and let the sides cave in. This results in rough cuts and obstructed bottom. Some trouble was experienced at first in getting the dredge men to do the work as required, but after a little explanation and re- quiring them to go back and dress the work not properly finished, they soon came to understand how to get the desired results. This is accomplished by taking a succession of light cuts on each side in such a way as to approximate the 1 to 1 slope, and then to excavate the center or core. The diagram issued for instruction as to this slope cutting is shown in Fig. 21. The prism is cut by digging the corners first and working to the center. It is especially insisted that light cuts must be taken in digging the corners, as indicated on the cross- section. The roll from the berm is cleaned on completion of the fifth round. Cross-Sectioning and Progress Records. The cross-sectioning of the ditches is done by sounding, taking measure'ments at the top, middle and bottom of each slope, and at 5-ft. intervals on the bottom for large ditches and 3 ft. for the small laterals. In- stead of entering the figures, in a book to be plotted later, the diagrams are plotted directly upon sheets of thin section paper, 17 x 10-in., clamped to a stiff board, the vertical and horizontal scales being 1 in to 10 ft. This eliminates much of the office work, and blueprints from the diagrams are very useful and effective in showing the contractors just what results they are getting and how these may be improved. Typical diagrams from these plotted cross-section sheets are HANDBOOK OF EARTH EXCAVATION Length of Move of Ditch 6' bevond Slope Stakes Plan Fig. 21. Diagram Showing How to Dredge Ditches With 1 to 1 Slopes. DITCHES AND CANALS 959 shown in Fig. 22, for both the large and small canals. These indicate the character of the actual excavation and the closeness with which the channels can be excavated to the theoretical sec- tion. In the smaller ditches the bottom is invariably concave instead of flat, but soon fills up practically to the grade' line. Dredging Canals on a Drainage Project in Louisiana. En- gineering and Contracting, Oct. 25, 1911, gives the following: The project here described is one of a great number now under Designed Sections /Ictual Sections Sections of the Smaller Ditches ^ ! /. 60' 5(T40 r 30' 10' JO' tf 10' 10' 30' 40' 50' 60' Sections of Ditch No.l : 1tO-r't. Base Fig. 22. Typical Ditch Cross-Sections Obtained With Dipper Dredges. way in the section near New Orleans. The two classes of land which are being reclaimed are the cut-over timber lands and the untimbered swamp lands. The timber lands cost considerably more to put into condition than do the swamp lands, because the heavy roots make the use of dredges impracticable. The method of drainage is as follows: The 2,850-acre tract is enclosed with a canal known as a dredge boat canal, the earth being thrown on the outer bank to form a levee which is smoothed down to make a road or driveway. When this canal and levee 960 HANDBOOK OF EAR1H EXCAVATION are completed two other large canals are dug at right angles to each other crossing the tract in each direction. See Fig. 23. These are for use for storage, to provide a large surface for evaporation, and essentially for the small lateral ditches to drain into. These lateral ditches are usually placed about 200 ft. apart. They are 3y 2 ft. deep, 4 ft. wide on top and 18 in. wide at the bottom. They are being dug by means of Hill ditching machines. The water is disposed of by a pumping plant designed to care for the maximum amount of rainfall, and stationed at the most convenient point for discharging water over the levee. The land in this district is composed of the material known as " sharkey clay," which is the sediment carried by the Mississippi River from the soils of the states through which it flows. This has been deposited here and gradually covered with a top soil composed of decayed vegetable matter. The soil is very rich and is not difficult to handle. The cost of reclaiming these tracts as based on the contract price of a number of 3,000-acre units is estimated by the engineers to be about as follows: For building levee and outside canal all round the tract, $8 per acre; for reservoir canals of. sufficient capacity to care for runoff from maximum rainfall, $7 per acre; for lateral ditches, $2 per acre; for pumping plant, $2.75 per acre; for engineering and superin- tendence, $2.25 per acre; for incidental expenses, $2 per acre, making a total of $24 per acre. The main drainage canal has a section 40 ft. wide on top and is 8 ft. deep. The main laterals are 18 ft. wide and 7} ft. deep and the ditches are 4 ft. wide and 3% ft. deep. All are made with banks at a natural slope. The general elevation of the ground is about 5 ft. above sea level. A pumping plant is under construction near the southeast corner of the tract. The excavation of the main canals was begun in the latter part of 1909 and was prosecuted almost continuously until the com- pletion in August, 1911. This work was carried on by means of two Marion dipper dredges, one with a %-cu. yd. and the other with a lVj>-cu. yd. bucket. The large dredge was on the ground when the work was begun and the small one was built afterward at a cost of about $8,500. Two oil barges of about 400 bbls. ca- pacity each were built to carry fuel oil for the dredges from New Orleans. All supplies had to be brought in on barges. One 25-hp. gasoline tug was used for all towing. The cost figures were taken from the company's books, with the exception of the charge for plant. This is an arbitrary figure based on an estimate of 25% depreciation of the plant for the two years' work. The small dredge was new and was built on the DITCHES AND CANALS 961 siic. -"l%e other dredge was used on previous work in the vicinity. Tin- ])la*t is taken as worth $20,500 at the beginning of work. The M>or charge is taken from the payroll account and includes Black Prince Boyou Fig. 23. Plan of Drainage Canals and Laterals for Reclaiming Louisiana Swamp Land. all labor charged to the contract, such as dredgemen, camp labor, clearing, towing, superintendence, etc. The supplies include all supplies except camp supplies. The repair account includes all repair parts and freight on same, but does not include the labor 962 HANDBOOK OF EARTH EXCAVA11ON for making repairs. The general expense account incudes all expense not included in other accounts, such as taxes 4H8<]plant, traveling expenses, railway fares of men, office expenses, efce. No interest is included. The fuel account includes only the oil used for the operation of the dredges. The rates of wages paid were for common labor $2 per day, engineman $125 per month, crane- man $65, fireman $50. The rates of the monthly men include board in addition. The costs follow: Plant (arbitrary) 0.8 General 0.6 Repairs 0.2 Supplies 1.4 Fuel 0.9 Labor 2.2 Camp 0.8 Total ct. per cu. yd 6.9 These costs are for the excavation of the main canals only, total- ing 675,000 cu. yd. The work of excavating the small ditches and the construction of the pumping plant are at present under way. Ditch Excavation by Natural Erosion. It is a waste of effort to cut some ditches to finished lines and to slope their sides. This is particularly so of ditches cut for stream diversions in connection with the building of railroads, especially in unde- veloped sections of the country. Many engineers lay out a ditch of relatively the same si/e as the oM channel of the stream, sloping and dressing up the sides of the ditch and giving it a fair gradient. This is usually a waste of money. If a stream has a channel varying from 6 to 8 ft. wide a ditch can be dug about 3 ft. wide, say wide enough to admit of excavating it with a drag scraper, and its sides left vertical. The grade given to it need be very slight. Then if the old channel is well drained, the water will be diverted into the new ditch, and the first heavy rain will excavate the ditch to its proper size and grade and the action of the water and frost will slope its banks. In diverting a stream in Arizona that had a, bed varying from 25 to 30 ft. in width, a ditch was laid off just wide enough to take a Fresno scraper, namely, from 4 to 5 ft. wide. The exca- vation was done with these scrapers at a low cost, the banks being left vertical. The grade was such that the water dammed up quite a little before it ran through the new ditch, but the first rains washed out a new channel about as wide and deep as the old one. However, this plan can not always be followed when the country is well settled and the land is valuable, for then it may be necessary to keep the stream under control. DITCHES AND CANALS 963 Bitch and Canal Excavation by Sluicing. Canals and ditches may be excavated very cheaply by first digging a narrow, shallow passage-way for the stream, and allowing the water to bring the ditch to its full width and depth by erosion of the banks and bottom. Very large waterways may be excavated in this man- ner. The chief disadvantage of this method lies in the difficulty of controlling the course of the stream. Water naturally washes away the softest materials, and the course of a ditch dug by this method will probably be very crooked. The direction may be controlled in some measure by plowing and loosening the earth as the water attacks it, as was done in the cases hereafter de- scribed. r l his method is then very low in construction cost but wasteful of land, and should therefore be pursued only where the value of land is low. Prof. B. M. Hall, in the Engineering Annual, University of Georgia, Vol. I, 1893, gives some data on sluicing methods used in swamp reclamation in Charlton county, Georgia. This swamp was a shallow, fresh-water lake, covering 400,000 acres, and filled with black muck. To drain it a narrow, shallow canal was cut through a ridge intervening between it and the river, at an elevation 20 to 25 ft. above the proposed bottom of the per- manent canal. This shallow canal was constructed by teams and scrapers. It was 17 ft. deep at the summit of the cut. To widen and deepen it a stream of water was pumped from the swamp, and a "porcupine" harrow (a round log filled with harrow teeth) was dragged up and down the canal a distance of 1,000 ft. at a time by steam power. The pumping plant con- sisted of two 80-hp. boilers and two 14-in. centrifugal pumps, lifting 30,000 gal. per min. The cost of excavation was only 2.5 ct. per cu. yd. The method used for draining the Okefinokee Swamp was also successfully pursued in excavating a canal near Laramie, Wyo. The methods and cost of the work are given by Lyman E. Bishop in Engineering News, Sept. 9, 1911, as follows: The work was the construction of part f the ditcher. The following table shows the work accomplished in one month: Hours on line 308V> Operation delays, hours 83 Time worked, hours 159% Cars loaded 970 Total cu. yd. loaded 15,520 The cost of the ditching crew per day was: Operator 3.34 Fin man 2.16 Two laborers at $1.55 3.10 Total $S.H This makes $224 for the 26 week days worked, or 1.5 ct. per cu. yd. for loading only. On this particular work the American railroad ditcher was used between two dump cars, which were dumped by hand, there being a laborer on each car for this purpose. These two men also handled the spreader car. On other ditching work on the South- ern two and sometimes three ditcher dump car work trains are used. Ditching with an Electrically Operated Ditcher. Engineering and Contracting, Jan. 15, 1010, abstracts the following by Charles W. Ford, from the Electric Railway Journal. On the Kansas City, Clay County and St. Joseph Railroad, a 78-mile electric line, an American railroad ditcher was placed in operation in 1015. The ditcher has a 20-hp. motor and oper- ates on 1,200 to 1,500 volts. It was the first electrically oper- ated machine of this type to be built. The ditcher is mounted on a specially constructed flat car 50 ft. long and with a capacity of 100,000 Ib. The ditcher travels back and forth on the car on two sections of 100-lb. A. S. C. E. rails, this being necessary in order to permit the flexibility of forward or backward motion when loading the shovel or, if the material is to be hauled, when un- loading into dump cars placed in front of the ditcher. A great amount of the material that is necessary to handle out of the ditches is a grade of clay which is exceedingly difficult to dig when dry, and is about the stickiest substance extant when wet. Rock and shale are common in the cuts along the line and a few years ago slides were not uncommon in wet weather. In most instances the material taken from the ditches and the cuts is de 070 HANDBOOK OF EARTH EXCAVATION? posited on fills, but in shallow cuts the material taken from the ditches is in maiiy cases deposited on the surface of the sides of the cut, thus providing an embankment which takes the place of surface ditches. This operation, which is much more rapid than is the use of dump cars, eliminates the haul entirely. The dump cars are of the side-dump type, holding 20 cu. yd. and are operated by air, the entire train being hauled by an electric locomotive. During 1918 it was necessary to use the ditcher for a period of only two months, and for the 60 days from May 1 to July 1, 1918, the following figures covering an average day's work have been compiled: Work: Right-of-way ditching, cut widening and bank filling. Material: Clay, fairly dry and tough, with some stone and shale Length of day: Fourteen hours. Time actually working: Seven and one half hours. (This in- cludes tht, time consumed in ditching, dumping, trav- eling to and from the siding, clearing for trains.) Crew used: Operator and two laborers: Train crew: Mo- torman and conductor. Daily Cost: Payroll $23.52 Power 5.00 Oil, waste and repairs ;... 2.50 Incidentals 1.26 Total $32.28 Average daily yardage, cu. yd 225 6 Cost per yard, ct 14.3 Fig. 26 shows the unit cost for different lengths of haul. A Ditching Car with Plows and Scrapers. Engineering News, May 7, 1896, describes a car equipped with plows, mold boards, scrapers, and excavator or ditching scoops, as used in 1895 on the St. Louis Southwestern Ry. This machine consists of a flat car, on which is mounted a compressed-air operated crane, from which are hung the cutting and loading devices. The method of working consists in cutting one or two furrows, 20 in. deep by 36 in. wide, with the plow, then using the scraper to bring the earth from the ditch up toward the track, or to throw it up and axvay from the track as desired, and finally to trim off the excavation with the mold board. The ditching scoop is used in deep cutting. It is filled in the manner of a drag scraper, hoisted up, and dumped when the car has been run to the dumping place. The force required consists of 1 conductor, 2 brakemen, 1 air- man, and 2 laborers, costing $18.30 per day. A locomotive is required for pushing the car, bringing the total cost up to about $30 per day. Under favorable conditions 1.5 to 2 miles of ditch and embankment were dressed in a day. DITCHES AND CANALS 971 The Bowman Ditcher. Engineering News, Jan. 20, 1910, givea the following : This machine (Fig. 27) is designed N for constructing or clean- ing railroad ditches. It consists of a car carrying four pneu- matic cranes (two on each side) for handling plows, scoops, slopers, and spreaders, air cylinders, air reservoirs, and three Westinghouse compressors. Steam for the compressors is sup- plied by the attendant locomotive. In operation, the ground is 45 600 40 700 "g 35 300 4 i \ ' V C'os^ p^r 'Cubic YoVxil -. Cubic Yards per Day V J \ V ^ V j \ V j 1*1"" ri~ ko 20-0300 ! a 15 800 10 100 5 V c L 1 S ONE MILE HAUL TWO MILE MAUL THREE MILE HAL FOUR MILE HAU ^ \ v 1 . t V ^ ^ / . - , /- z. - v S, \ " y ^ /i ^ /i ^ S .. r g * c \ \k V u '* V s \ ^ ^ i ^ ^ ^ ^ 1) ? _p ^ ^ ^ S , ' *\ ^ ^ ^ **fc f ^ s * * ^ ^ * ** i k s 3 1^ S 4+ s, * N "* s J i* % f ^ % S| ' Jj ^ * - "* '*N > , - ~ ^. "1 . \\ '< - ^ , S rf "^l ^ e. r< r- i \ ^ >* $5 - > 4 5 y at- taching ropes to the drag, placing a team on each bank and dragging the plow in the channel r the mass was broken up. After pulling out the logs and wire (dynamite being used some- 980 HANDBOOK OF EARTH EXCAVATION times to dislodge them) the water floated out the silt. A close measurement of the silt and drift removed from the channel was not made, as the work was done under the day labor, system, but approximately 2,800 cu. yd. were taken out, the cost being the fol- lowing items: Four team drivers, at $3.50 each for 24 days $336.00 Two drags with ropes and fixtures 10:00 Dynamite 5.00 Foreman, 24 days at $2.50 60.00 Total at 15 ct. per cu. yd $411.00 In the fall of 1912, Seaton's ditch, near Missouri Valley, was cleaned and deepened. This is a drainage ditch 7,600 ft. long with 6 ft. bottom width, and side slopes 1 to 1. During the rainy season and for a time afterward the ditch carries water but is usually dry during the fall months. The work of cleaning was done by contract at 19 ct. per cu. yd. The contractor bid to do the work with teams, but the ground proved too soft for this method, and a small drag line dredge was purchased and the work successfully carried out with this, which proved to be an excellent machine for the work. The machine was made of light timber construction. The framework, 16 ft. wide, was mounted on rollers and designed to work astride the ditch in clean-out work. The power was generated by an 8-hp. gasoline, which also served to move the machine forward or transport it from one job to another along the country roads if the distance is not great. It used a one-third yard scoop. Two men operated it, us- ing about 10 gal. of gasoline per day. About 250 cu. yd. of earth in ten hours was the capacity of the machine on the job in ques- tion. The machine is of wood construction and is not very dur- able, but as most of it is of sizes kept in all lumber yards, de- fective parts can be easily replaced. I Navigable Canals. These are usually dug through fairly level ground. Their even depth, the continuous use of the same cross- section for great distances, and the large amount of excavation, lead to the use of highly specialized excavating machinery. The Panama Canal. This was dug under such special circum- stances and conditions as to make it unwise to include data on its construction in this chapter. Approximately a quarter of a billion cubic yards of earth and rock were excavated. Reports of the Isthmian Canal Commission, containing considerable cost data, are available to any one who wants to study the subject. A further reason for excluding data on the Panama Canal from this chapter is that it crosses such rough country that the use of special canal excavating equipment was impossible. DITCHES AND CANALS 981 The Chicago Drainage Canal. This was dug during 1894 and 1895, largely with steam shovels. Fig. 29 shows the arrangement x of the steam shovels and in- clines as operated by one of the Chicago Canal contractors. The traveling incline is provided with a tipple very similar to those used in coal mining. The shovel first takes out a cut 8 ft. deep the full length of the excavation, as shown in Fig. 29 marked 1st cut. The next cut is carried to a depth of 15 ft. and the third cut to a depth of 20 ft. below the original ground level. After the third cut is made, the excavation is carried no deeper until * A-B-E. ,-*~ ^ -i- .. _.v**** i^ Fig. 29. Arrangement of Steam Shovels and Inclines. by successive slices the full width of the channel has been ex- cavated. The top lift of 20 ft. being removed, work is begun at the edge of the slopes of the bottom lift exactly as before. In the plan, Fig. 29, the incline or conveyor 4 shows ropes for pulling the approach trestle of the incline forward ; a horse whim or block and tackle to the engine being used. The engine and incline proper are carried on a car, the machinery being merely a 10 x 16-in. double cylinder hoisting engine of 75 hp. Actual experience on the Chicago Canal has proved that such an incline can handle 900 cu. yd. per 10-hr, day, day in and day out, the steam shovel being in fact the limiting factor. The trussing of the incline proper and the working of the tipple are shown in Fig. 30, in which M is a sheave around which the cable from the 982 HANDBOOK OF EARTH EXCAVATION engine passes to the sheave E, thence to the car; G and H are counterweights that pull the tipple back after the load is dumped. The engineman at no time sees the car, but slows up when he hears the bell rung by the car whose wheel flange strikes a bell lever near the tipple. The front wheels of the car strike a buffer L; the car stops and as the engine is still pulling on the cable, the tipple revolves, dumping the load out of the front end of the car. As the tipple revolves it pulls a wire that operates an indi- cator in the engine room, so that the engineer knows when to re- Fig. 30. Incline and Tipple. lease the cable and let the tipple revolve back. The brake for controlling the descent of the car is operated by a brakeman standing on the incline where he can always see the car. Since there are two cars and two cables there are two brakemen on each incline, each man having a lever connected by wires with the brakes on the engine drum. One of these inclines complete with engines is said to have cost $4,000, and the cost of operation of a steam shovel and an incline per 10-hr, shift was as follows: 4 tons of coal @ $2 $ 8.00 Repairs 8.00 22 men @ $1.50 to $3 44.00 Total <: $60.00 Operating continuously from September, 1894, to July, 1895, on the Chicago Canal in hard clay the average output per shift on two sections was 670 cu. yd., making the cost about 9 ct. per cu. yd., not including interest and depreciation of plant. The cost of coal, labor and repairs is about equally divided between the steam shovel and the incline. One contracting firm, with 2}-yd. shovels, made cuts 20 ft. wide x 20 ft. deep, and moved each shovel forward about 13 times in 10 hr.. making a 6-ft. move each time. It took 2 min. to move the shovel forward, and the incline with the approach trestle rigidly fastened to it was moved at the same time. Each car held 5 cu. yd. place measure, and DITCHES AND CANALS 083 was filled with three shovel loads. A %-in. wire cable was used in hoisting" and its life was 150,000 cu. yd. of material excavated, the cars being moved 350 ft. horizontally and 60 ft. vertically. Another method of attack using a shovel and incline is shown in Fig. 31. In this case the shovel makes cuts across the axis of the canal instead of parallel with it. It will be noticed that in this case a bridge was used to dump through instead of a tipple, but this same method of shovel attack has also been used with Block Fig. 31. Shovels Used with Incline and Dumping Bridge. the tipple incline just described. Using a 1^ cu. yd. shovel, cuts 15 to 20 ft. wide x 16 ft. deep were made, the shovel work ing for 1 hr. and then moving forward 14 ft. When a cut has been made clear across the canal, the shovel is run around the curved track, as shown at AB, while the working track is shitted close up to the face of the work. At the same time the bridge and incline are shifted by horses a distance of 20 or 25 ft., the whole time so occupied being about 50 min. The cars used with 984 HANDBOOK OP EARTH EXCAVATION this bridge conveyor hold 9 cu. yd. water measure, which in blasted hardpan is taken to be equivalent to 5l/ cu. yd. place measure. The car has an A-shaped bottom and swinging side doors that are readily tripped, and its dead weight is 10,000 Ib. The bridge is a single track combination wood and iron Pratt truss, traveling on tracks as shown. The shovel is the limiting factor, but a maximum output of 210 car loads in 10 hr. has DetaiiofT.ppie Showing Met hod of Framing Plan Fig. 32. Details of Tipple Incline. been attained, although 150 car loads was the average. The force engaged on the Chicago Canal in tough clay was 1 shovel engineman, 1 cranesman, 1 fireman, 5 shovel tenders, 12 laborers breaking down face and trimming slopes, 2 men on bridge truss, 1 engineman and 1 fireman on incline, a total of 24 men besides a foreman. Two centrifugal pumps, one 8-in. and one 10-in. lifting 3,000 gallons per min. 50 ft. high, were used to keep the pit drained, and in this connection it should be observed that pump- DITCHES AND CANALS 985 ing cost 1 to 1.5 ct. per cu. yd. Work was suspended during February, March and April, and in the month of Jan; ary the shovel output was 20 to 30% below the average of other months. Fig. 32 shows an all steel incline and tipple used on one sec- tion instead of the bridge conveyor, but with the same method of shovel attack at right angles to the canal axis, shown in Fig. 31. It will be observed that there was no approach trestle used in connection with this incline, and that the engine house was on a separate flat car. The steel trusses of the incline weighed 5,800 lb., and the total load of boilers, flat cars, etc., was 100 tons. The engines were 11 x 18-in. double Mundy, and with the boiler cost $2,700. The shovel cut was 20 ft. wide x 18 ft. deep and the best month's record was 920 cu. yd. per 10 hr. shift, which was the best record made on the canal for a month. The Bates Belt Conveyor, Chicago Canal. On section G of the Chicago Sanitary District Canal, a belt conveyor designed by Lindon W. Bates, was installed. The original machine was built with two belts, one horizontal belt across the canal and up the slope, and a second belt up and across a movable bridge. The weight of the load held the belt down at the bottom of the slope. These belts were 22 in. wide, the pit belt being 450 ft., and the spoil bank belt 500 ft. long. The belt traveled on rollers across the valley and up over a movable bridge, off which the earth was scraped by 6-ft. scrapers. The slope of the bank belt was 2.5 to 1. The material was clay, excavated by a steam shovel. As the clay was delivered by the shovel in large lumps, it was necessary to break the lumps up in a " granulator " similar to that used by brick manufacturers. Rain and snow caused slipping and clog- ging of the belt, and the pit had to be kept dry as the belt would stall when loaded with mud or wet material. The plant consisted of a 60-hp. Toledo steam shovel, a 120-hp. granulator, and a 50-hp. power car driving the belt. The force employed was as follows: The belt force consisted of 2 foremen, 1 engrneman, 1 fireman, 3 carpenters, 12 pickmen and slopers, 1 dumpman, 1 beltman and 1 oilman. The granulator force consisted of 1 foreman, 1 engineman, 2 laborers, 1 leverman and 1 hopperman. The shovel force consisted of 1 shovel engineman, 1 trainman. 1 fireman and 2 pitmen. The general force consisted of 1 coal passer, and 1 coal cart and driver. Mr. Schnable, in the Journal Association of Engineering So- cieties, June, 1895, gives the output of this machine as follows: From May until September was consumed in installing plant, 986 HANDBOOK OF EARTH EXCAVATION excavating a pit and in loading the belt by manual labor as well as in experimenting. In October, 77 cu. yd. were excavated per day. In November 920 cu. yd., in December 313 cu. yd., and in January 319 cu. yd. The cold and numerous breakdowns re- duced the output for December and January. Mr. Lewis puts the possible maximum output per 10 hr. day of this plant as 1,200 cu. yd. Mr. Schnable's paper gives the general design of this con- veyor. This belt conveyor plant was "not very successful. N. Y. State Barge Canal Work. Engineering and Contracting, Sept. 28, 1910, gives an outline of the work and costs of handling material with five machines on Contract 42 of the New York Barge Canal. The work was done in April, 1909, on lock 20 and 8.96 miles of canal. The material handled consists largely of black gumbo (clay), there being little or no rock on the entire contract. Work was commenced in the summer of 1909 at the western end of the con- tract. At this point three New Era graders, 36 wagons and slip scrapers, and 68 head of mules were employed. The erection of the larger machines was soon put under way and by spring of 1910 all the machines, of which costs are herein given, were work-- ing. These machines consist of one Heyworth-Newman dragline excavator, two electrically driven Lidgerwood dragline machines, a Field tower operating a drag bucket, and a 12-in. hydraulic dredge. All machines were operated with three shifts of 8 hr. each. The Lidgerwood machines, however, were working at a disadvantage as they were moving to new points during this month, and the amount of excavation shown for them is merely that skimmed off the surface while moving. The following data show the costs of excavation per cubic yard for the month of April, 1910. These costs include labor, repairs and distribution of field office expenses: Heyworth-Newman Excavator, 100-ft. Boom; 2% Yd. Bucket: 1 operator $ 4.00 1 .ioreiiian " 2.00 5 laborers 7-50 1 foreman, average $85 per mo 2.83 1 pumpman 1-50 1 oiler 2.00 1 team 1 shift a day 4.50 Total cu. yd. for April 23,192 Total cost for April $1,983.84 Total cost per cu. yd $ 0-085 Hydraulic Dredge " Mohawk," 12-in. suction : 1 captain, per month $ 150.00 3 enginemen, per month 3 levermen, per month 1 mate, per month 120.00 6 deckhands, per day , 2.00 DITCHES AND CANALS 98? 3 firemen, per day $ 2.00 8 laborers or pipemen, per day 1.60 Total cu. yd. excavated '. 15,557 Total cost $1,726.30 Cost per cu. yd $0.111 Two Lidscerwood Excavators, Electrically Operated, with 25- hp. Motor for Swinging and 125-hp. Motor for Hoist; 2V 2 -Yd. Page Bucket: 1 operator, per day $ 4.00 1 oiler, per day 2.00 5 laborers, per day 1.50 1 sloper, per day 2.25 1 foreman, $85 per mo 2.83 1 electrician, $125 per mo 4.17 Total cu. yd. excavated Mach. No. 1 2,271 Total cost $1,667.80 Cost per cu. yd $ 0.735 Total cu. yd. excavated by Machine No. 2 2,583 Total cost $ 992.30 Cost per cu. yd $ 0.384 The two Lidgerwood machines worked only part of the time dur- ing this month, No. 1 working 13 days and No. 2 working 10 days during the month. As mentioned above both were engaged in moving to new positions and were working at a disadvantage. The yardage for these machines should be about the same as for a Heyworth-Newman machine under similar conditions. The dif- ference in daily pay roll is, however, in favor of the electrically driven machine. The electric power on these machines costs about 1 ct. per cu. yd. City current is used and a transformer is placed at con- venient points along the line, as the machine moves ahead. The repairs on the Heyworth machine have averaged, approx- imately, $400 per month. The highest amount charged to repairs for any one month is $667. The Field Tower Scrjzper is a new machine for this class of work and is one of the evolutions of the work on the Barge Canal. It consists of a movable tower, located on one side of the canal with a cable running from it to an anchorage on the opposite side of the canal. The drag bucket is supported by and slides up and down this cable. It is pulled back and forth by. an endless line. The crew and costs are as follows per day: 1 operator $ 4.00 1 fireman, $75 per mo 2.50 1 foreman or superintendent, $200 per mo 6.67 1 pumpman 1-50 6 laborers at Total cu. yd. excavated 15,065 Total cost $1,455.81 Cost per cu. yd * 0.096 This tower is 85 ft. high and operates a l%-cu.-yd. bucket with a 10 x 12-in. hoisting engine and 40-hp. boiler. This ma- 988 HANDBOOK OF EARTH EXCAVATION chine is becoming quite popular along the canal because of its adaptability and its moderate cost. Bridge Conveyor Excavator. This machine, used on contract No. 6 of the New York State Barge Canal, is described in Engi- neering and Contracting, Nov. 23, 1910. This excavator was erected in 1907 by the Pittsburg Steel Construction Co. Com- pletely equipped it cost $105,000. The conveyor, Fig. 33, consists of a two-truss " bridge " supported by two steel towers and having a cantilever arm extending beyond the towers over the spoil banks on each side. The bottom chords of the " bridge " carry the truck on which the bucket trolley moves. The towers are 90 ft. high and each rests on a "car" consisting of a framework of Fig. 33. Bridge Conveyor Excavator on New York State Barge Canal. steel girders riding on 32 car wheels. The wheel base of these cars is 36 ft., and the cars run on structural gage tracks, one on each side of the canal. One tower, that adjacent to the shorter cantilever arm, is rigidly attached to the car frame. The oppo- site tower rests on its car frame on two sets of roller bearings. One set of roller bearings permits the tower to move across the car in the line of the axis of the " bridge " ; the other set permits the tower to swing on an arc lengthwise of the car or at right angle to the axis of the bridge. The first set of roller bearings permits a certain variation in distance between the cars, and the second set permits one end of the bridge to be " swung " ahead of the other when occasion demands. The total amount of this swing is an arc of 17. DITCHES AND CANALS 989 The cantilever arms differ in length, that adjacent to the fixed tower being 96 ft. span and the opposite one being 128 ft. span. The reason for this design was that the original plans called for the earth to be wasted on one bank and the rock on the opposite bank. The ratio between the lengths of the cantilevers is the ra- tio between the widths of spoil banks as figured on the engineers' estimates of the amounts of earth and of rock excavation. The longer arm was to provide for the larger rock spoil bank. It may be noted here that this original plan for the separation of the earth and the rock spoil has not proved to be completely practicable and has been only partially accomplished. The operating mechanism consists first of the mechanism for operating and controlling the excavating bucket, and second of the mechanism for moving the conveyor along the work. All this mechanism is operated by electric power. A service transmission line along the canal brings current at 4,100 volts a. c. from the plant of the Rochester Railway & Light Co., to a transformer car att'ached to one of the towers and traveling with the conveyor. At this point the 4,100-volt alternating current is transformed to 2GO-volt direct current and led to the various operating motors. One set of feeders passes up the tower to a set of contact rails suspended from the lower chords of the bridge. From these rails it is taken by contact shoes on the trolley and conveyed to a switchboard and controllers in the trolley cab. Another set of feeders runs to four 30-hp. motors which move the conveyor along the work. These motors are geared to drums carrying cables the ends of which are led ahead to deadmen on opposite banks of the canal. To control the travel of the conveyor there is an electric brake on each car; these brakes are applied automatically when the current is shut off from the motors. The trolley is propelled back and forth along the " bridge " by two 60-hp. motors, and a round trip from the middle of the bridge to either end and return requires about 1^ minutes including the time for dumping the bucket. An air brake is arranged to stop the trolley at any desired point and there is also an electric emergency brake to prevent over-running in case of failure of the air brake. Air for this brake and also for the brakes on the hoist, which are mentioned later, is supplied by a small electrically driven compressor located on the trolley. The bucket is of the clam-shell type and is operated by two pairs of cables, one for opening and one for closing the jaws. Each pair of cables is wound on a separate drum and each drum is operated by two 80-hp. motors. To lower the bucket the clos- ing cables are run slack and the opening cables sustain the bucket until it touches the ground when the opening cables are 990 HANDBOOK OF EARTH EXCAVATION also slacked off to permit the jaws to bury themselves in the spoil. As soon as the bucket is buried, the closing cables are hauled in to close the jaws and then both pairs of cables, opening and closing, are operated to hoist the bucket and its load. The com- bined power of all four motors, or 320-hp., is thus available for hoisting. The controllers for the bucket operating drums are inter-connected with air brakes so that as soon as power is thrown off the drums are locked fast and the bucket can be lowered only at will. The bucket weighs 9 tons and has a nominal capacity of 8 cu. yd. The actual load grasped, however, averages more nearly 3 cu. yd. A single operator in the trolley cab controls all move- ments except that of pulling the conveyor ahead which is directed from a cab in one of the towers by the oiler. The conveyor requires nominally three men, an operator, an oiler and an electrician. The full crew working is larger, and the total wage charge per 8-hr, day includes the following items: 1 operator $6.00 1 electrician 4.00 1 oiler 3.25 2 to 5 laborers at $1.50 and $1.60 $3.00 to 8.00 1 team 4.00 1 watchman 2.00 Bookkeeper, part time at $125 per mo. Timekeeper, part time at 80 per mo. Superintendent, part time at 250 per mo. The records of operation of the conveyor, which have been secured, cover the work of the calendar years 1908 and 1909. During this period the machine was laid up an aggregate of about two months because of repairs due to a fire and to the breaking of the bucket. . The cost of removing earth and rock were not kept separate. In 24 months 510,406 cu. yd. of rock and 39,721 cu. yd. of earth were removed at the following cost per cu. yd. Repairs $0.0400 Electric power 0.0484 Drilling 0.0212 Blasting 0.0715 Removal of spoil 0.3091 Total per cu. yd $0.4902 This cost does not include interest or depreciation. It will be noted that practically all the excavation was rock. Since 1 cu. yd. of solid rock makes about 1.7 cu. yd. of broken rock, if we divide the 40 ct. cost of " removal of spoil " and " re- pairs " and power by 1.7 we get about 24 ct. as the cost of load- ing and conveying a cubic yard of loose material, which would DITCHES AND CANALS 991 be about the cost of handling earth with this bridge, conveyor, exclusive of interest and depreciation. During the 24 months the conveyor handled 510,000 cu. yd. of solid rock (equivalent to about 860,000 cu. yd. of earth) and about 40,000 cu. yd. of earth. Hence it would have handled 900,- 000 cu. yd. of earth in 24 months, or 37,500 cu. yd. per month. Costs on the N. Y. Barge Canal. In a paper presented before the Philadelphia Engineers' Club and published in the July Pro- ceedings, 1911, Wm. B. Landreth, former Special Deputy State Engineer in direct charge of the Barge Canal construction, pre- sented data showing the contract prices of barge canal construc- tion covering several years. These prices are for the larger items of contract work and show large variations in prices bid for various classes of work. The first contracts were let in 1905, and bids have been received several times every year since that date. This period covers at least one rather severe financial de- pression and two periods of increased cost of work. But one unit price is paid for excavation as there is no classi- fication of the material excavated. The actual cost to the contractors as shown in the cost data records, including depreciation, interest and overhead charges, has been as follows per cu. yd. : EARTH EXCAVATION By hydraulic dredge from $0.05 to $0.16 By dipper dredge from 0.13 to 0.30 By ladder dredge from 0.15 to 0.25 By clamshell dredge from 0.09 to 0.15 By revolving excavator and scraper bucket. from 0.05 to 0.28 By towers and scraper buckets from 0.11 to 0.30 By steam shovel from 0.10 to 0.40 By graders from 0.14 to 0.30 By hand and team from 0.14 to 0.60 ROCK EXCAVATION Dry rock by steam shovel from $0.30 to $0.75 Dry rock by hand and derrick $2.00 (average) Wet rock from $1.00 to $2.25 Channeling has cost from 22 ct. to 38 ct. per sq. ft., depending on the character of the rock, the rock channeled having varied from soft, badly broken shale and slate to hard limestone. Scraper Boat for Sloping Canal Banks. A machine for sloping the banks of the New York State barge canal to anv required grade was devised by A. S. Robinson and described in Engineering Record, May 23, 1914. It consisted of two scows joined together but separated so as to leave a well between them (Fig. 34). In this well was the base of two triangular cantilever trusses. These trusses supported a track on which a 1-yd. drag-line bucket oper- 992 HANDBOOK OF EARTH EXCAVATION DITCHES AND CANALS 993 atcd. This bucket had a lateral movement of 30 ft. for one set- ting of the boat. The cutting edge of the bucket scraped the soil downward into the water where a curvature of the track caused the bucket to tip and dump its load. The bottom of the canal was previously excavated by suction dredges to a depth sufficient to receive this material. Ihe back of the bucket had two flap valves Fig. 35. Details of Bank Sloping Dredge. opening inward for the purpose of permitting water to enter and wash out the bucket on its return trip. Another boat for shaping canal banks is described in Engineer- ing and Contracting, Nov. 9, 1910. It consists of a derrick set on one of two barges which are each 17^ x 75 ft. and fastened parallel to each other with a 10 ft. space between. (See Fig. 35.) The engine for operating the derrick and bucket is set on the second barge opposite to the location of the derrick. The der- ' 994 HANDBOOK OF EARTH EXCAVATION rick is equipped with Terry & Tench fittings. The dimensions are indicated on the drawing, which shows the method of operating the bucket. The bucket (Fig. 36) digs with an upward motion, being pulled by the line attached to the cutting end. Two lines are fastened to the rear of the bucket, one of which -runs over a sheave in the end of the boom and is used to dump the bucket. The other runs directly from the back of the bucket through a sheave at the base of the mast and is used to haul the bucket back. The lines are operated by an 10 x 12-in., double drum, Lidger- wood engine. Two other engines, each 6x10 in., located near the bow, are used respectively to operate the lines connected to dead- men up and down stream, and to op.erate the spuds. One operator, a fireman and five men constitute the usual crew on this machine. j ,' '5!"^vvvv-;-i-.-v-.--f. J '' x' PI r * Aws i T ! / r I ' i ' 3 :-: V' Fig. 36. Bucket for Bank Sloping Dredge. The work done varies according to the amount of material to be trimmed off. The machine has trimmed from 50 to 400 lin. ft. of bank per day of 8 hr. Templets are set at various intervals ( about 25 ft. ) along the banks, indicating the correct slope and the grade to which the operator works. The slope is produced by holding the boom at a certain angle with the horizontal, which once having been found by the " cut and try " method, generally need not be changed while digging the one class of material. This " sloper " was designed by George E. Field. There were 20,000 ft. B.M. in the derrick, trusses and housing, exclusive of the lumber in the scows. Cost of Steam Shovel Work, North Shore Channel, Chicago. Engineering and Contracting, Aug. 4, 1909, gives the following posts of work on Section 1 of the North Shore Channel of the DITCHES AND CANALS 1)05 Sanitary District, Chicago. This section comprises the pumping station and lock, the crib work piers protecting the intake, the lock and 3,350 ft. of channel. The work was done by the Sani- tary District on force account. The top 10 ft. of channel excavation consisted of a clay which could readily be dumped from dump cars, but below this the clay was heavy and tenacious and came in large lumps. It was exca- vated by a 70-ton Vulcan steam shovel with a 3-cu. yd. dipper. The steam shovel loaded into Western 3-cu. yd. dump cars which were handled by Davenport locomotives out of the cut and onto the crib piers behind which the spoil was dumped. These cars were dumped in the usual way until the sticky clay was met, then they would not dump properly. A derrick was then ar- ranged to do the dumping. A sling was devised which would hook into and lift the car body from the trucks and by winding up on the engine would tilt the body and empty it. The cost of .excavation, as kept by the engineers, was as fol- lows for 1908, when 194,280 cu. yd. were excavated: An 8-hr. day was worked and the wages paid were as follows: Men on dump per day ................................... $1.50 Men around shovel per day ............................. 1.75 Steam shovel enginemen per month .................. 125 to 150 Steam shovel cranemen per month ...................... 90 The value of the excavating plant was $16,035, and the as- sumed depreciation chargeable to Section 1 was $16,035 X 50% = $8,017. The cost of excavation (194,280 cu. yd.) in 1908 was as fol- lows per cu. yd. : Materials : Total Per Cu. Yd. Operation ........................... $8,639 $0.044 Repairs and plant ................. 7,156 0.036 Total materials ................. $15,795 $0.081 Labor: Operation ........................... $32,241 $0.166 Repairs and plant ................. 3,295 Total labor ..................... $35,536 $0.182 Grand totals ................... $51,331 $0.264 The items making up these totals were as follows: Materials : Operation Rep. & Pint. Total Shovel ........... $1,208 $1,502 $2,710 .. , Dump ........... 259 259 996 HANDBOOK OF EARTH EXCAVATION Materials: Cars , Coal Operation . $ 216 Insurance General . . 136 Totals $8,638 Labor : Shovel $8,728 Dinkeys 5,876 Track 5,951 Dump 9,146 Cars 34 Coal 585 Office Insurance 606 General 1,315 Rep. & Pint. $1,863 360 $7,156 i 820 359 1,975 8 103 Totals ........ $32,241 $3,295 Total $ 2,079 6,066 360 197 $15,795 $ 9,548 6,265 5,951 9,146 585 1,418 $35,536 The costs of operation in excavation were distributed as fol- lows: Steam Shovel: Total Labor $8,880 Coal 3,326 Supplies 1,208 General 539 Totals $13,953 Per cu. yd 0.072 '''I: Transportation : Labor $6,023 Coal 3,326 Supplies 1,003 General 182 Totals $10,534 Per cu. yd , ... 0.054 Track : Labor $6,102 General and supplies 190 Totals $6,292 Per cu. yd 0.032 Dump: Labor $9,298 Supplies . . General '. '. 539 Totals $10,094 Per cu. yd 0.051 Grand totals $40,873 Per cu. yd 0.209 The costs of repair and plant charges were distributed as fol- lows: DITCHES AND CANALS 997 Steam Shovel: Total Labor .... $ 280 Materials ' 1,502 General 177 Totals $2,499 Per cu. yd 0.006 Transportation : Labor $2,364 Material 3,011 General 177 Totals .......................................... . $5,552 Per cu. yd ....................................... 0.014 Track : Materials ............................................ $2,222 General .............................................. 177 Totals $2,399 Grand totals $10,450 Per cu. yd 0.027 In figuring the net costs of repairs and plant charges the total estimated amount of excavation on the section, or 390,000 cu. yd., has been used as the divisor. The reason for this is that the repair and plant charges itemized were all that were necessary to put the plant in shape to complete the work. Summarizing we have: Operation $0.2095 Repair and plant charges 0.0266 Depreciation on plant ,.... 0.0205 Total per cu. yd $0.2566 Cost with Dragline Excavators on North Shore Channel, Chi- cago. Sections 4 and 5 of the North Shore Channel, Chicago, were dug under contract. The top-soil on both these sections was excavated with teams and drag scrapers. In this way 47,000 cu. yd. were removed from section 4, and 21,000 cu. yd. from section 5. The balance of the cut was made with Heyworth-Newman dragline excavators, one machine working on each section. En- gineering and Contracting, Apr. 27, 1910, gives the following data on their operation. On section 4, from Sept., 1908, to Dec., 1909, inclusive, 490,062 cu. yd. were removed, or an average of 31,191 cu. yd. per month. On section 5 201,712 cu. yd. were moved from May to Dec., 1908, inclusive, an average of 25,214 cu. yd. per month. hutf ; i An estimate of the cost of labor for one machine is as follows: No consideration is taken of interest on contractors' bond, in- surance, or of general office expense. The work is divided into three shifts of 8 hr. each for the operators, and two shifts of 12 098 HANDBOOK OF EARTH EXCAVATION hr. each for the balance of the crew. The work is carried on 6 days a week or 25 days a month. The figures were obtained by the editor while going over the work and are given according to the information furnished him. He believes, however, that the crew given for each machine is too large. It would be more nearly correct to eliminate the items of mechanic, blacksmith's helper and oiler; and to divide the blacksmith's time between three machines. The monthly payroll was: 12 laborers at 20 ct. per hr $ 720.00 3 operators at $150 450.00 2 firemen at $90 180.00 1 man and team 125.00 1 supt. to 2 machines at $200 per month 100.00 1 civil engineer and timekeeper, $125 2 machines. 67.50 1 mechanic, 3 machines at $150 50.00 1 blacksmith 90.00 1 blacksmith's helper 50.00 1 oiler 60.00 Total per month $1,892.50 Using 31,191 cu. yd. excavated for Section 4 and 25,214 cu. yd. excavated for Section 5, the costs per cubic yard are estimated as follows: Section 4 Labor $0.061 3 tons coal per 24-hr, day 0.010 Repairs and miscellaneous supplies 0.048 15% annual interest on $15,000 plant 0.006 50% annual depreciation on $15,000 plant 0.020 Total per cu. yd $0.145 Section 5 Labor $0.076 3 tons coal per day 0.012 Repairs and miscellaneous supplies '.. 0.059 15% annual interest on $15,000 plant 0.007 50% annual depreciation on $15,000 plant 0.030 Total per cu. yd $0.184 The labor item includes all work done, such as repairs, mov- ing machine, and actual excavation. The " repair and miscellaneous supplies " item is large. It contains new cable, oil, renewals and 2 miles of 2-in. pipe to sup- ply water to the boilers. The strains and work demanded of large dragline machines are heavier than steam shovels. The average repair and maintenance bill has been $1,500 per month for two excavators. The annual interest and depreciation charges are estimated high in order to make allowance for periods of idleness when no con- tract is underway. DITCHES AND CANALS 999 Tower Dragline Excavator on North Shore Canal, Chicago. A machine invented by J. T. Fanning, which is said to have worked very close to required lines, cutting less than li/ cu. yd. of excess material per lin. ft. of canal, is described in Engineer- ing and Contracting, Jan. 18, 1911. Fig. 37 shows the principles upon which the machine operates. There are two towers and two buckets. In each tower is located a double drum engine which operates one of the buckets. The booms, which extend on an incline to the rear of the tower and over the spoil bank, are also offset horizontally from the center lines of the towers. This can better be understood by reference Fig. 37. Method of Operation of Double Bucket Tower Excavator. to the plan. The boom on one tower is offset to one side of the center line which runs between the two towers, and the boom on the other tower is offset to the opposite side of this center line. In this way a straight line from the apex of one tower to the end of the boom of the opposite tower, shows a clear working line for the bucket. A similar condition is presented for another bucket to work in the opposite direction. Each bucket is operated by two lines. The drag or digging line is run from the small drum of the double drum engine to the bucket which digs downwardly on the opposite bank of the canal. The bucket is dragged down the slope, with its other line slack, and takes its load. The other line of load line runs from the large drum on the engine up over a pulley near the apex of the tower, then put over another stationary pulley which is sus- pended from a cable placed between the two towers, down through 1000 HANDBOOK OF EARTH EXCAVATION \ a sheave attached to the bale of the bucket, and out to the end of the boom on the opposite tower. By winding in on this line and holding the dragline, the bucket is raised until, by slacking the dragline, it can be run down by gravity to the dump pile at the end of the boom. Ihe location of the bucket in digging was controlled partly by the location of the fixed pulleys suspended above the canal section. The positions of these were changed from time to time to suit the requirements of the work. The bucket is of %-yd. capacity, and is arranged so that a tripping device, near the end of the boom causes the bottom of the bucket to swing loose and drop the load on the spoil bank. In operation the skill with which the bucket is handled de- pends upon the experience of the engineer. The work is always in plain view of the operator, and by proper manipulation of the lines the slopes may be carved down at any angle desired. The constant rubbing of the buckets down the slope carries all loose material down the bank, and produces a compact and plane surface. The bucket travels very easily and rapidly out to the end of the boom, the speed being controlled by the angle of the line on which it runs and by the dragline. Some speed is necessary to enable the bucket to throw out its load. The speed is desir- able because the clay sticks to the bucket. The principal disadvantage comes in the wear of the dragline which bears a considerable strain when used to stop the bucket. The material excavated is clay. The section of the canal mea- sures 26 ft. wide at the base with slopes of 1 on 2. The aver- age depth of the canal on the sections which this machine was used, is about 27} ft. The country through which the canal runs is a practically level plain. The machine was used on two sections of the North Shore Drainage canal, covering a period of two years. It was operated 10 hr. per day with an engineer and fireman in each tower, and a track gang consisting of about 5 men. An average of 12 men, including the superintendent, watchmen and all labor, was employed. The maximum yardage excavated, during one month, was in June, 1910, when 19,000 cu. yd. were excavated. The min- imum yardage for a complete month was excavated in December, 1908, when 4,750 yd. were taken out. The average amount of excavation per working day was between 500 and 600 cu. yd. It was possible for each bucket to make two trips per minute, but the output per day shows that each bucket averaged less than one trip per minute. The new machine, for which plans are being niade, will be built stronger throughout, and a larger bucket will be used. DITCHES AND CANALS 1001 Costs of Excavation on Colbert Shoals Canal, Ala. Charles E. Bright, in Engineering and Contracting, Oct. 18, 1911, gives the following: Colbert Shoals Canal, which was designed to overcome the obstructions to navigation at Colbert and Bee Tree Shoals, is located along the south, or left bank, of the Tennessee River; the lower end of the canal being about one-half mile above Riverton, Ala. It is a lateral canal 8 miles long, with a lock of 26-ft. lift, 80-ft. width, and 350-ft. length, located at the lower end. Beginning at the upper end of this lock and extending upstream for a distance of 5.3 miles, the canal was excavated through the bottom lands, the cutting ranging in depth from 17 ft. at the lower end to 20 ft. at the upper. The cross section of the canal is 112 ft. wide at the bottom or at grade, with side slopes of 1 on 2. Berms 15 ft. w r ide be- tween slop stakes and the toe of spoil banks were left on both sides of the canal, the berm on the river side being brought to a height of not less than 0.5 ft. above low water in the canal. Excavation w y as done on different sections of the canal with wheel-scrapers, elevating graders pulled w 7 ith traction engines, dragline excavators and steam shovels. The elevating graders were not generally successful. Grass and cornstalks clogged the elevator on one part of the work so that it was necessary to strip the surface with wheel scrapers. All of the graders used were what is termed " Standard West- ern Elevating Graders," with 21-ft. elevator, using an extra heavy or giant railroad plow for loosening the material and throwing it on the elevator. This plow was attached to one side of the frame of grader. The only portion of the canal completely ex- cavated to grade by these machines was from Stations 10-20 to 145-103, which proved unprofitable on account of the material usually becoming too hard near the bottom to be loosened by the plow. The height to which the material had to be lifted in get- ting it to spoil banks was too great. These machines, in con- nection with wheel scrapers, were most successfully used in mak- ing a cut from 8 to 12 ft. in depth, and 110 to 120 ft. in width, off the top. This left a strip about 30 ft. wide inside the slope stakes on each side for the drag bucket excavators to work from in taking out the remainder of the section. This arrangement gave the elevating graders the soft material to which they were best adapted, and, at the same time, the least lift in conveying the material to spoil banks. The steam shovel outfit consisted of a 65-ton Marion shovel, one 25-ton and one 20-ton dinkey locomotive, and eight " Oliver " 12-yd., side dump cars, all standard gage; with about 1% miles 1002 HANDBOOK OF EARTH EXCAVATION of track, a tank, and pipe line and pump for supplying water to shovel and locomotives. The dragline excavators were Armstrong machines equipped with an 81 -ft. boom and a 2-cu. yd. Page scraper-bucket. The machine was moved on skids with wooden rollers. Quantities Handled and Cost by Various Methods Per. Cu. Yd. Wheelscrapers, 207,408 cu. yd $0.20 Graders, 917,138 cu. yd 017 Dragline, 889,267 cu. yd 0.11 Steam shovel, 187,559 cu. yd 28 The wheel-scrapers, elevating graders and steam shovel having removed the cream of the excavation in most instances, the drag- bucket excavators were left the hard material which was mostly found near the bottom, besides being required to lift the material to a greater height. An advantage of the drag-bucket excavators over the wheel-scrapers, elevating graders and steam shovel, was their ability to work successfully in pits containing from 2 to 3 ft. of water, and the fact that ordinary rains did not interfere with their output. It was also the only machine on which two and three shifts per day were worked profitably. The daily expenses by each method were as follows: Drag-Bucket Excavators : 3 enginemen at $260 per month $8.66 3 firemen at $2 6.00 3 laborers at $1.50 4.50 1 master mechanic at $125 per month 4.16 1 pump man 1.50 1 blacksmith 3.00 1 foreman at $75 per month 2.50 1 coal wagon driver 2.00 Total per day $32.32 Cost for each of 3 machines - 10.77 Elevating Graders : 2 enginemen at $80 ($160) $ 5.33 2 firemen at $1.75 3.50 16 teams (four-horse) at $2.50 40.00 water wagon, with driver 2.00 pump man 1.50 blacksmith 3.00 helper 1.50 foreman at $75 per month 2.50 Total per day $59.33 Cost for each of two graders 29.66 Wheel Scrapers: 15 wheel scrapers at $2 $30.00 3 snap teams at $2.25 6.75 5 laborers at $1.75 8.75 1 blacksmith 3.00 1 helper 1-50 1 foreman at $75 per month 2.50 Total per day $52.50 Cost for each scraper 3.50 DITCHES AND CANALS 1003 Steam Shovel: 1 foreman at $125 per month $ 4.16 1 shovel engineman at $125 per month 4.16 1 craneman at $90 per month 3.00 1 shovel fireman 2.00 1 blacksmith 3.00 1 helper 1.50 1 pump man 1.50 1 coal wagon 2.00 2 dinkey engineers at $2.00 4.00 2 firemen at $1.50 3.00 2 brakemen at $1.50 * 3.00 16 laborers on dump at $1.50 24.00 3 laborers at shovel 4.50 Total per day $59.82 Bibliography. " Hand Book of Construction Plant," R. T. Dana ; " Excavating Machinery," A. B. McDaniel ; " Practical Farm Drainage," C. G. Elliot ; " Irrigation Engineering," Her- bert M. Wilson ; " Irrigation Engineers' Hand Book," Herbert M. Wilson. Reports of the Isthmian Canal Commission, Panama Canal. " The Soulanges Canal Works, Canada," C. R. Coultee, En- gineering News, April 18, 1901 ; " Chicago Drainage Canal," series of articles in Engineering Record, April 4, 1896, to April 17, 1897; " Excavating Methods and Equipment on Cape Cod Canal," En- gineering News, Feb. 19, 1914; " Bucket Ladder Excavators on the Spanish Canal, Alfons XIII, from Seville to the Atlantic," Engi- neering and Contracting, Sept. 3, 1913. CHAPTER XVIII HYDRAULIC EXCAVATION AND SLUICING To California gold miners and mining engineers the world is indebted for the development of the cheapest means known for moving earth. Engineers in general are apparently strangers to the great economy of the hydraulic method of excavation, or if not ignorant of its economic merits as applied in California, they hesitate to use the method elsewhere. However, there is nothing mysterious or difficult about the hydraulic method of ^arth exca- vation, nor does it always require so great an expenditure for plant as to put it beyond the reach of those contemplating exca- vations of any considerable size. It is generally assumed that there must be a gravity supply of water, but even this condition is no essential to economic excavation and transportation of earth, as we shall presently see. There are three methods employed in sluicing : ( 1 ) the ground- sluice; (2) the "boom," and (3) the hydraulic giant. In the ground-sluice method, which is best adapted to shallow banks, the earth is shoveled or dumped into a stream of water running in a sluice. In this method the water is used to convey the material and not to loosen it. A " boom " consists of a temporary dam behind which the water supply is allowed to accumulate until a sufficient amount is stored. The water is then allowed to escape with a rush, the stream being directed against the foot of the bank to be re- moved. This method has been used in Colorado. Hydaulic Giants. A giant or monitor is a metal tube and nozzle tip so fixed to a pipe by flexible joints as to be easily moved horizontally or vertically. The tapering nozzle varies in diameter from 1 to 10 in., at the tip, and is fitted with a deflector attached at its extremity for the purpose of directing the stream to the desired point of attack. See Fig. 1. Bed Rock Sluices. In opening up a gold-bearing gravel bank for hydraulic sluicing bed rock sluices are frequently constructed. These are channels cut in the underlying bed rock for the pur- pose of conveying the material to the outlet pipe or sluice or to the dump. The grade of the bed rock sluice is determined by the contour of the ground, the quantity of water available, and the character of the material. Sand requires a heavy grade which may be par- tially compensated by making the sluice wide and shallow. Heavy boulders require a deep narrow sluice. The usual grade is 6 in. per "box" of 12 ft. in length, or 4.2%, but will vary from 1 in. to 12 in. per " box." The grade should increase slightly towards the dump. Curves should be avoided if possible. It is 1004 HYDRAULIC EXCAVATION AND SLUICING 1005 sometimes necessary to set the sluices in tunnels but open cut sluices are preferable. The size of the sluice is also regulated by the quantity of water used, according to H. A. Brigham, Journal of the Asso- ciated Engineering Societies, vol. 41, 1908. For washing fine ma- terial the size of sluice required is about as follows: Quantity of water Miner's in. (1.5 cu. ft. per sec.) 200 to 600 400 to 1,200 1,000 to 2,500 2,000 to 4,000 3,000 to 5,000 4,000 to 7,000 Width of sluice ft. 3 4 5 10 Fig. 1. "Bouery's" Hydraulic Giant. The most economic method of constructing bod rock sluices is to blast the material, wash out the debris with the hydraulic giant, and line the sluice if necessary with timber. The Carrying Capacity of Water. To the engineer, the most important data relating to hydraulic excavation are results of actual practice showing the number of cubic yards of material excavated by a cubic foot of water. The most complete informa- tion on this subject is given in a paper on " Hydraulic Mining in California," read by Mr. A. J. Bowie, Jr., in 1877, before the American Institute of Mining Engineers. From this paper, which goes into great detail, I have condensed and tabulated the ac- companying Table II, which is based upon actual measurements and is reliable. The total yardage was 2,275,967 cu. yd. gravel moved per \533,728 miner's inches (2,159 cu. ft. each), or 1.48 cu. yd. moved per miner's inch, which is equivalent to about 1,440 cu. ft. 1006 HANDBOOK OF EARTH EXCAVATION of water per cu. yd. of gravel; 12,027 oz. of gold worth $231,893 were recovered, the average yield per cu. yd. of gravel being 10.2 ct.; 554 Ib. of quick-silver were lost. The average cost per cu. yd. of gravel moved was: Water $0.008 Materials 010 Labor 0.036 Office and general expenses 006 Total per cu. yd $0.060 Two shifts were worked and 1,520 (24-hr.) days were required to move the two and a-quarter million cubic yards, or about 1,500 cu. yd. per 24-hr, day per plant. TABLE I COST OF HYDRAULIC EXCAVATION: NORTH BLOOMFIELD CLAIM NO. 8 Year 1874-5 1875-6 Cu. yd. gravel 1,858,000 2,919,700 Height of bank, ft 180 260 Grade of sluices, in. in 16 ft 6% 6^ Labor per cu. yd $0.0122 $0.0140 Powder per cu. yd 0032 .0053 Materials per cu. yd .0030 .0031 General expenses per cu. yd .0022 .0025 Water per cu. yd .0077 .0074 Total per cu. yd $0.0203 $0.0323 Cu. yd. of gravel per miner's inch 4.80 4.17 Cu. ft. water per cu. yd. gravel 450 520 The foregoing indicates about the maximum cost of hydraulic excavation on a large scale, for the banks were not very high, the head of water was low, and the flumes were laid on a very gentle grade all of which factors increase the consumption of water, as is well shown by comparison with Table II. Contrast Table II with the following data, Table III, on the North Bloomfield Mine which is rearranged from a table given by Mr. Bowie. Here the grade of the sluices is 9% instead of 2%. TABLE III DATA ON NORTH BLOOMFIELD MINE 1874 1875 1876 1877 Height of bank, ft 100 100 200 265 Grade of sluices, in. in 12 ft. 6% e 1 ^ 6% 6% Cu. yd of gravel 3,250,000 1,858,000 2,919,700 2,993,930 Cu. yd. per miner's inch .. 4.6 4.8 4.17 386 Cu. ft. water per cu. yd... 436 459 540 567 Sluices on the North Bloomfield Mine were 6 ft. wide by 32 in. deep, while those used for the La Grange Mines were 4 ft. wide by 30 in. deep. We see from Tables I to III that the cubic feet of water HYDRAULIC EXCAVATION AND SLUICING 1007 . g 3 - l - ^ Qr at O' . * < 4) 1 w .sg ifSJ* . a Scg: .M I | 1008 HANDBOOK OF EARTH EXCAVATION required to move each cubic yard of gravel may be from 450 to* 2,000; and that the cost of labor alone may be 1.25 to 4.25 ct. per cu. yd. It appears that ordinarily about 1,000 cu. ft. of water are required to loosen and move each cubic yard of gravel where banks are, say, 30 ft. high, with about 85-ft. head of water. As illustrating the expense to which certain companies have gone, the 55 miles of main ditch of the North Bloomfield Co. may be mentioned. This ditch was 5 ft. wide at bottom, 3,5 ft. deep, and side slopes were 1.5 to 1. Ihe grade was 12 to 16 ft. per mile, and the delivery 3,200 miner's inches, or about 6,900,000 cu. ft. per 24 hr. Ditches with grades of 20 ft. per mile and de- livering 80 cu. ft. per second have been built, and it is to be noted that gagings show about 25% less discharge than open-channel formulas would indicate. Where ravines are crossed, timber flumes 4 ft. wide by 3 ft. deep laid on grades of 30 to 35 ft. per mile are used. The sluices into which the loose gravel and water are run are made of 1.5-in. plank, tongued and grooved about 3 ft. wide x 3 ft. deep ; cross-sills, 4x6 in., support the sluice every 4 ft., being mounted on 4 x 6-in. posts. The sluices ordinarily have a 4% grade, and one of the size just given will carry 3,200 miner's inches on a 4% grade; 6 to 8% grades are used where pipe-clay is to be moved. The water must run at least to 10 or 12 in. deep in the sluice, so as to cover boulders of that size and facilitate their moving along. A sudden break or drop-off in the sluice line can be used to effect the disintegration of cemented gravels. -Banks of cemented gravel, often weighing 3,600 Ib. per cu. yd., or 133 Ib. per cu. ft. in place, are broken up by using black powder. If the bank is 50 to 125 ft. high a tunnel is run in about two-thirds the height of the bank, and at the end of the tunnel lateral drifts are run parallel to the face, forming a T. One-half to % keg (25-lb.) of powder per 1,000 cu. ft. of gravel, measured in front and above the lateral drift, is the charge placed in the lateral drifts, tamped and fired. As illustrating the accuracy of sampling the yield of gravel determined by test pits and drifts, one example will suffice. Excavations from which 21,600 tons of gravel were taken actually yielded $2.75 per ton in gold, while the estimated yield by sampling was $2.00. For data on bank blasting see Chapter V. Many data on the " duty " of water are given by A. J. Bowie in " A Practical Treatise on Hydraulic Mining." Amounts vary- ing from 1 to 7.5 cu. yd. are given as transported by a miner's inch in 24 hr. This is roughly from 1 to 10% as many cu. ft. of material moved as there are cu. ft. of water used to move it. On Yuba River, Calif., some 19,100,000 cu. yd. of gravel were HYDRAULIC EXCAVATION AND SLUICING 1009 moved with 3.5 miner's inches per cu. yd. On American River, Calif., 8,015,000 cu. yd. required 4.5 miner's inch per cu. yd. Volume of Water* for Hydraulicking. Table V was compiled by engineers of the Union Iron Works Co., San Francisco, Cal., published in their catalog No. 5, on hydraulic excavating ma- chinery, and given in Engineering and Contracting, June 12, 1912. TABLE V WATER REQUIRED FOR EFFECTIVE HYDRAULICK- ING, CU. FT. PER MIN. Htead 2-in. 2%-in. 3-in. 4-in. 5-in. ft. nozzle nozzle nozzle nozzle nozzle 100 120 188 278 488 750 150 150 233 338 600 938 200 158 270 390 690 1,073 250 195 300 435 773 1,200 300 210 330 480 848 1,320 350 225 360 508 915 1,425 400 240 383 548 975 1,500 The catalog gives a table for nozzles up to 10 in. and heads up to 700 ft. The volume of water increases as the square of the diameter of the nozzle. The Miner's Inch. Engineering and Mining Journal, May 26, 1904, gives the following: In the California Journal of Technology, A. P. Stover gives the number of miner's inches assumed in different states to equal a flow 7 of 1 cu. ft. por second. By custom By statute California 50.0 40.0 Colorado 38.4 38.4 Montana 40.0 40.0 Idaho 50.0 Arizona 40.0 Nevada 50.0 Utah 50.0 In Nevada the miner's inch in one part of the state may be measured under 4-in. pressure, while in another part under 6 or 12-in. pressure. Along the Humboldt River water, in some cases, is measured under pressures of 2, 3.5, or even 4 ft. The great difficulty is to obtain a constant head; this may be done with flows of small volume by use of a proper measuring box, but it is impossible with flows of several hundred feet per second. Ditches and Flumes. Where lumber is cheap and where the required life of the water supply line is not much more than 10 yr., the cost of a flume is frequently less than that of a ditch. A larger amount of water per unit of section area is carried by flumes than by ditches. Waste gates should be placed every y to i mile. Giants have been designed to accelerate the movement of ma- 1010 HANDBOOK OF EARTH EXCAVATION terial through Humes, ditched and ground sluices. See Fig. 2, which shows a " booster giant " made by the Joshua Hendy Iron Works, San Francisco. A Giant and Hydraulic Elevator Plant. Engineering News, Jan. 16, 181)6, gives the following: In an exhaustive paper on " The Present Condition of Gold Mining in the Southern Appalachian States," by Messrs. H. B. C. Nitze and H. A. J. Wilkens, presented at the Atlanta meeting of the American Institute of Mining Engineers, the authors de- scribe a novel method which is about to be used in reworking the Fig. 2. A Booster Giant. old placer-deposits on the Mills property, Burke Co., N. C. The work is described as follows. The deposits are situated near the headwaters of Silver Creek. They are about a mile in length and are located mainly upon the west bank upon which the gravel often extends out a distance of 500 to 600 yd. The main difficulty encountered is the want of fall in the bed, a feature common to many Southern placers. It amounts in this case to less than 1 ft. in 100. To overcome this obstacle for hydraulicking with continuous sluice, the use of the hydraulic gravel-elevator was decided upon, and some ex- periments were made with it a few years ago. In the main, they were satisfactory, but were soon abandoned, the plant being unfit for continuous use, and monazite not being at that time a valu- able product. HYDRAULIC EXCAVATION AND SLUICING 1011 1012 HANDBOOK OF EARTH EXCAVATION Fig. 3 gives a rough sketch of the plant and method to be car- ried out by the present company. Twelve miles of ditch and flume line ( 1 ) carry the water from a reservoir, through the Dan Sisk gap in the South mountains, to a penstock (4), sit- uated 200 ft. above the level of the creek bed. The ditch is cut about 8 in. deep by 20 in. wide, at a cost of about 25 ct. per rod, and is given a grade of from li/ to 3 in. wide by 12 in. deep. The water, before reaching the penstock, flows through a sand- pit (2, Fig. 3), to catch sand, etc., washed into the ditch line from the side. It then enters the penstock after passing through 4. H>draulic Gravel Elevator. a screen (3) for removing leaves, sticks, etc. The pipe (5) run- ning from the penstock is 10-in. spiral riveted sheet-steel (No. 16 Birmingham gage), coated with coal tar and connected with flanges. Smaller curves are made by placing cast-iron beveled wings between the gaskets of the flanges, larger ones by suitable elbows. Near the gravel pit the 10-in. pipe branches out through a Y (0) into two 7-in. pipes, supplied each with a gate-valve, one leading to the giant (10) and the other to the hydraulic elevator (7), These are both of California type and manufacture. HYDRAULIC EXCAVATION AND SLUICING 1013 An illustration of the elevator is given in Fig. 4. The prin- ciple of this device is too well-known to require a description. It is intended to keep the elevator stationary as long as possible, as its installation consumes considerable time. A pit must be sunk in the bed-rock, and as the elevator must also drain the workings (a drain on the top pf the bed-rock to the initial point of work- ing was considered too expensive ) , the water would gain too much headway while the elevator is moved. The work in the main pit will be carried diagonally up the banks of the stream, so as to gain as much grade as possible. As soon as there is room, a sluice box (!)) will be placed between the working-bank and the elevator pit. The upper part of this sluice will be filled with 3-in. by 4-in. blocks and the remainder by 1-in. by 3-in. cross-riffles, placed 11 in. apart and held down by a sand-board, which is halved down on them. Both will help to protect the sluice box against wear. All pebbles, etc., more than } in. in diameter will be forked out of the sluice and left in the pit (11). After being raised by the elevator, the material will pass through another sluice (8), the tailings from which will be worked for monazite. It is expected that by far the largest part of the gold will be saved in the first sluice. T;*; ; An Incline and Giant. In Siskiyou County, Cal., according to Engineering and Mining Journal, Nov. 16, 1912, an incline and a giant are use,d instead of a hydraulic elevator. The incline is an inclined trough, usually 8 ft. wide and 80 to 100 ft. long. The sides range from 12 ft. wide at bottom to ft. at top. The bottom is composed of two sets of 1^-in. plank. A bridge, usu- ally 10 ft. long, of well supported boards, extends from the gravel to the incline. This bridge and the first 20 ft. of the incline are lined with % in. steel plates. In operation two or more giants are employed : the first cuts down the deposit and the second, located about 80 ft. from the bridge, washes the material up and over the sloping bridge by the driving power of the water. As much as 1,200 cu. yd. of gravel per day have been handled by two No. 3 giants using 1,200 miner's inches of water under 450-ft. head. Boulders as large as 5 ft. in diameter are driven over the incline. In some of the placers this method is used in pits 20 to 25 ft. deep. The machine is unhandy to move. Four men with a capstan, block and tackle and a mule will change the location of a ma- chine in 8 or days. The cost of operation is stated to be or 7 ct. per cu. yd. Hydraulic Elevator Work in Alaska. Ihe following is given by C. W. Purington in Mining and Scientific Press, Apr. 26, 1913. 1014 HANDBOOK OF EARTH EXCAVATION Unfrozen gravel is handled on claims of the Pioneer Mining Co. on Anvil Creek, Nome, Alaska, with a hydraulic giant, assisted by a bedrock sluice, a hydraulic elevator and a nozzle for wash- ing away the tailings. The gravel is coarse and sub-angular, with many medium sized boulders. Eighteen men and 1 team are employed on each 10-hr, shift. About one-half the men are em- ployed cleaning bed rock, and the team of horses is used for re- moving stones larger than 8-in. in diameter, that will not go through the elevator throat. The duty of the miner's inch considering all operations is 2.63 cu. yd., or 30.4 cu. yd. of water are required to move 1 cu. yd. of gravel. The total amount of water used during an operation of 29 days in September and October, 1911, was 15,733 miner's inches which moved 41,415 cu. yd. Of this water only 20.4% was used for the piping giant, while 4.2% was used for the bedrock sluice, 8.3% for the tailings giant, and 67.1% for the hydraulic elevator. If all the water available was used for piping giants, then the duty of the miner's inch would have been about 12.38 cu. yd. for an average daily yardage of 6,716 cu. yd. The elevator was of the Campbell type, having a 10.5-in. throat and upcast pipe 15 in. in diameter. The bed rock sluice was of steel, and the face was carried as much as 150 to 250 ft. from the throat of the elevator. This machine raised the gravel 26.5 ft. Transporting Sand Through a Pipe with the Aid of an Ejector. Engineering and Contracting, July 7, 1909, gives the following: For transporting sand from a scow to a tank, a distance of 630 ft., an ejector was used. A line of 4-in. cast iron pipe ran from the ejector to the tank. The total lift from the scow to the tank was 30 ft. The sand was shoveled into a hopper attached to the ejector. The diameter of the nozzle of ejector was 1^ in., and the diameter of the water jet was 1 in. The water pressure at the jet was 110 Ib. per sq. in. There were 80 cu. yd. of sand transported per 10-hr, day by this method. Incidentally the sand was well washed, for the overflow water from the tank car- ried off the silt. Removing Muck from a Bridge Caisson by a Hydraulic Ele- vator. Engineering and Contracting, July 12, 1911, gives the following relative to work on the sub-structure of a bridge at Vancouver. The hydraulic elevator is operated on the same principle as a steam syphon or ejector, water being used at about 100 Ib. pres- sure to lift the material out of the pit. The elevator (Fig. 5) consists of a V-tube through which the water is forced. The " down " pipe is 4 in. in diameter and the " up " pipe 5 in. Near the lower end of the up pipe is a Y-branch leading to the HYDRAULIC EXCAVATION AND SLUICING 1015 material to be excavated. The material is agitated by means of a jet pipe which also is shown in the drawing. The former method used for taking out the soft muck first en- countered in the caisson was to blow it out through a pipe by means of the air pressure in the caisson. This could only be done intermittently because of blowing off all the air. By tha hydraulic elevator the operation is continuous and the air pres- sure within the caisson may be maintained. No trouble has been experienced by the air escaping, as one might suppose. When the elevator is not actually excavating, a board is placed under the Wire Wound 'fire Host Hydraulic Jet used as an Agitator 3 Lines of Double , Jacket Fire Hose ^J'ClftexMe Joint 'Hydraulic Jef. IngContq. Jevotion of Elevator Fig. 5. Hydraulic Elevator and Jet Used for Excavating and Discharging Material from Caissons of Vancouver Bridge. suction and the water from the pump is simply allowed to flow through the pipes. The pump used is a duplex pump furnishing water at 100 Ib. pressure at the pump. By a comparison of the two methods in caissons of equal size 16 ft. square it was found that with the use of air pressure 123 cu. yd. were blown out in 42 hr., whereas 115 cu. yd. were taken out in 19} hr. with the hydraulic elevator. This is 2.93 and 5.90 cu. yd. per hr. respectively, or an increase of 100% by the use of the hydraulic elevator. Pressure Boxes. A pressure box is located at the intake of 1010 HANDBOOK OF EARTH EXCAVATION the pipe line leading to the giants. It should be spacious and the water should stand 4 ft. or more deep over the entrance to the pipe to prevent the entrance of air. Provision must be made for the overflow when the gates in the pipe line are closed. Pipe Lines for Hydraulic Mining. Engineering and Con- tracting, Dec. 11, 1907, gives the following: In hydraulic mining in Alaska the water is distributed from the pressure box to the monitors and elevators by means of wrought-iron or more generally, steel-riveted pipe, usually made up in sections 17 to 19 ft. long. Sheet steel is used, from 8 to 16 U. S. standard gage, bent, each plate, 30 or 36 in. long, being riveted in double rows lengthwise and single on the ends. The sizes used vary from 8 to 36 in. Fig. 6. Reinforcing a Slip Joint. The pipe is shipped by the manufacturers, either made up and riveted ready to be laid with slip joints, or the material is supplied in short plate sections, bent, punched and furnished with necessary rivets, ready to be cold riveted on the ground. Sections of pipe are put together by slipping or by flange or lead joints. If it is advisable to reinforce a slip joint, the device shown in Fig. 6 which can be macle quickly in a blacksmith shop, is often used. The sleeve, lugs and keys should be made of soft steel. In laying pipe from the pressure box to the placer claim, the line should be started at the lower end, and the joints slipped in down the slope. In cold climates the best practice is to lay the pipe line in a slight lateral curve, so that subsequent contrac- HYDRAULIC EXCAVATION AND SLIICLNGJ 1017 tions of the units may be remedied by pushing the pipe into a more nearly straight line. The pipe should be laid as nearly straight as conditions will allow, and elbows and bends of small radius should be avoided. Various methods of " setting " the pipe are used. In Oregon the device shown in Fig. 7 is used in setting and unsetting pipe. Fig. 7. Oregon Method of Jointing Pipe. The wrench is made with reversible parts, so that the position of the leverage can be changed for the different operations. An- other device sometimes used in British Columbia is shown in Fig. 8. It consists of a square block of timber 3 ft. x 3 ft. x9 in., Fig. 8. British Columbia Method of Jointing Pipe. faced with ifo-in. steel plate, to which is bolted a disk-like wooden plug the diameter of the pipe inside. Two men batter the timber with mallets. Lead joints are seldom necessary in Alaskan operations, the almost universal practice being to use slip joints. On steep declivities pipe joints are braced and strengthened by means of lugs and wiring as shown in Fig. 9. Ditch Construction in Alaska. Chester W. Purrington, in a U. S, Geological Survey Bulletin, abstracted in Engineering and Contracting, Jan, 1, 1918, says that ditches on the Seward Penin- sula are made wjtti breaking plows, scrapers and road graders, 1018 HANDBOOK OF EARTH EXCAVATION all being drawn by horses. Four or eight horses are used on a grader, two to four on a scraper. Special methods are necessary when the ditch passes through sections underlain by ground ice, or runs over sections of rock that are broken and fractured. It has been found bad practice to cut through the stringy moss which overlies the masses of ground ice, generally referred to as " gla- cier." In fact it is disastrous to the permanency of that section of the ditch, and is the beginning of never-ending repairs, since the ice continues to thaw, causing constant leakage. The best practice is to build sod walls on the lower side, leaving the moss Fig. 9. Bracing Pipe on Slopes. undisturbed. All rock work must be done by hand, and where the ditch passes through fractured material all cracks must be filled with moss. Too much care can not be observed in the latter de- tail, and, especially during the first weeks of use, men must be kept constantly traversing and repairing those sections where leaks are apt to occur. The stirring up of the water by men walking along the bottom of the ditch is a good practice in the early stages, for silt, in addition to the sod, is a most valuable factor in filling the cracks. A scraper will work to great advantage in decayed schist, which needs no lining, as it holds water better than any other ground encountered and cuts out less. Fluming does not pay when there is a possibility of ditch building. In fact, it has been often stated by men familiar with ditch construction, that where pos- sible, it is profitable both as regards first cost and subsequent maintenance to build a ditch in place of fluming, even if the dis- tance necessary to be covered by the former be ten times that of the latter. Many slopes apparently not permitting a ditch cut, owing to the presence of broken rock and talus slides, on close examination are found to be favorable, for if 2 or 3 ft. of this loose material is moved there are excellent opportunities for comparatively cheap HYDRAULIC EXCAVATION AND SLUICING 1019 rock cuts. When, however, it is deemed impracticable to con- struct a ditch, and where a flume must be built crossing a gully, a very efficient foundation can be made by digging shallow holes, filling with gravel, and placing on top a wide plank to distribute the load. If the trestle rests on such foundations, and the under- lying ice is not disturbed, much trouble from settling will be avoided. The following are a few of the costs representative of ditch- ing in various materials: Per cu. yd. Soft muck and tundra $0.75 Gravelly dirt 0.65 Decayed schist $0.40 to 0.60 Rock work, fairly solid 1.75 Schist in place 1.00 Loose rock 1.25 A ditch carrying 1,000 miner's inches will cost, under fair con- ditions, $2,000 per mile. One with the capacity of 4,000 miner's inches will cost between $4,000 and $5,000 per mile. Though much affected by varying local conditions a conservative estimate for general work is $1 per cubic yard throughout. A Simple Timber Flume. Two flumes, over 800 ft. long and 2y 2 x 2 ft., and one 400 ft. long and 5x4 ft., were required to be built for the Santa Rita Mining Co., in Colombia, South America, and only native carpenters with peon helpers were available. All framing had, therefore, to be designed so that measuring and thinking would be unnecessary by the carpenters. The design se- lected to meet the conditions and the method of constructing the flume are described in Engineering and Mining Journal by R. D. 0. Johnson and abstracted in Engineering and Contracting, Apr. 17, 1912. The boards were all !} in. thick and 12^ ft. long, making the flume boxes average 12 ft. in length. Since it cost as much to edge and to handle a 6-in. board as it did a 12-in. board, the use of narrower boards was not frequently allowed. All boards were sawed by hand, the sawyers working in pairs. The sawyers were at first put at day's pay, but it soon became evident that the lumber would cost $40 per M. It always pays to put the peon on contract where possible. As the peon knows nothing of the measurement of lumber by the board-foot unit and as it appeared a hopeless task to explain it to him another method had to be devised. The work of the best pair of sawyers was taken as a guide and a schedule of prices was worked out for each size of board or timber needed. These prices were calcu- lated on a cost of $18 per M, the prices being a small amount higher for the thin and narrow boards and a small amount less 1020 HANDBOOK OF EARTH EXCAVATION for the large boards and timbers. This scale of, prices was ac- companied by simple specifications as to the kind of timber ac- ceptable, full dimensions, bark edges, worm holes, rotten spots, etc. Contracts were given to each pair of sawyers for a limited num- ber of boards and timbers on the basis of the specifications and price schedule. Each sawyer was charged 25 ct. gold per day for his board, the cost to the company being somewhat below this figure. It was found desirable to give small contracts rather than large ones. Boards were inspected each day and a record of the work of each pair of sawyers kept. Failure to keep to the U -7-- Q.Q Fig. 10. Cross Section of Timber Flume Built by Colombian Native Labor. specifications was met with the penalty of severe docking. The prices were found in practice to be about right as, on the con- tracts, the better sawyers could make about 50% more than the ruling day's pay for sawyers, and the poorer ones were either eliminated or had to be content with less than the ruling rate. In searching for bunches of good trees, so that the cost in time and labor in handling the logs would be less, the sawyers would sometimes go to great distances from the sites of the fiumes, making the cost of collecting boards excessive. To obviate this difficulty a price of from 1 to 3 ct. a board, de- pending upon the size, was added to the contract price and the sawyers were required to deliver their boards at the flume site. All boards were brought to dimensions and edged at a price of 5 ct. per board. The boards were 'not tongued and grooved, reliance HYDRAULIC EXCAVATION AND SLUICING 1021 for the tightness of the flumes being placed on careful edging. As the boards were finished they were marked and distributed along the lines of the flumes. As the woods were full of small and fairly straight trees, it was determined to make the frames out of the round timber without even going to the trouble and expense of taking off the bark. The accompanying cross-section of the flume (Fig. 10) shows the frame, the parts of which are of much, more ample diameter than the working stresses would ordi- narily require, but the timber was plentiful and the large di- ameters made up for the mark and the weakening due to the cutting out of crooks and bends. Miter boxes were used to cut the sins, caps, posts and braces to reduce the cutting to mere mechanical operations. The sills, caps and braces were of round timber cut on con- tract, sills G ct., caps 3 ct. and braces 1 ct. each. The cutting of the posts required the combined labor of three carpenters and was not given out on contract. The wedges were made from 1^-in. hardwood boards, 10 in. wide, and sawed into 12-in. lengths. These short sections were inserted in the wedge miter box, wedged tightly, and sawed. Each 12-in. section makes four wedges, two rights and two lefts. For the total number of wedges the labor of one carpenter for six days was required. As the sills were completed they were laid out upon the shelf excavated to receive the flume, lined up carefully, spaced and given the proper inclination on the curves. When all the boards had been sized and edged and all parts of the frames formed up and distributed along the line of the flume, four native car- penters and four helpers (peons) laid the flume at the rate of 120 ft. per day. The process was as follows: The ends of the boards of a box were carefully fitted to the end of the preceding box already laid, the lower side boards were then spiked to the outer bottom boards; the bottom as a whole was then carefully adjusted to the centers of the sills, the posts set up and the wedges started. The center bottom board was then spiked to the sills, the lower side boards spiked to the posts, the caps placed and spiked and the wedges driven up hard. The outer bottom boards were then spiked to the sills and the braces driven into their recesses in the sills and posts and spiked. The posts were not spiked to the sills, so that the wedges could be driven up later if it appeared desirable to do so. The necessary sequence of the operations involved in laying the flume was care- fully explained to the carpenters and, with a little practice, they acquired the " swing " and the work thereafter moved off at a satisfactory rate. Little calking of the flume was found neces- sary. Although i/ x 3-in. battens were provided, few were used. 1022 HANDBOOK OF EARTH EXCAVATION Exclusive of the work of excavating the shelf and on the two trestles on the line, the cost of the smaller of the two flumes was 45 ct. per running foot. Movable Flume on Hydraulic Fill Dam. The following ap- peared in Engineering Jtecord, Jan. 6, 1917: During the construction of a large hydraulic fill dam recently Fig. 11. Discharge Flume Easily Moved on Inclined Skids. completed in the West, considerable time was saved by the use of an inclined runway for the flume from which material was de- posited on the dam. Although the flume was moved by hand, it was only necessary to interrupt the flow for short periods while the delivery flume was skidded up the incline to the desired new position. See Fig. 11. HYDRAULIC EXCAVATION AND SLUICING 1023 Three borrow pits were used, from which, by means of hydraulic giants, material was sluiced into three main flume lines. From these mains the material was conveyed through flumes along the upstream and downstream sides of the fill. By the use of gates the streams were discharged from the flumes at the desired inter- vals toward the axis of the dam. The flume box, 12 x 24 in. in section, was built up of 1^4-in. boards and was paved with 6xl2x6-in. hemlock blocks set on end. Immedrately above the blocks 1 x 6-in. projecting strips were nailed on each side. This box was supported on 2 x 6-in. stringers, which in turn were carried by 4 x 6-in. caps on the low sliding bents spaced 15 ft. apart and inclined on a slope of 5 to 1. The 6 x 6-in. inclined caps were supported on pieces of the same size resting on the material previously deposited and tied together by cross-bracing. The flume proper was moved up the incline by means of a lever and chain device at each bent. The lever consisted of an iron bar near the lower end of which was fastened a chain connecting with the framing of the flume box. At the extreme lower end of the bar a second chain was attached which passed over an iron claw fastened to the upper end of the inclined 6 x 6-in. cap. This lever was operated by one man at each bent. With the lever in an upright position, pulling it down through the quadrant, which it was possible to describe, would move the flume up the incline a few inches. This gain was then caught by taking up slack in the chain at the claw, and the operation repeated. Short lengths of lateral flumes were attached to the openings in the up side of the flume box to facilitate control of the flow. Doors for closing the openings were provided, so that material could be discharged at any desired point along the crest of the fill, a duplicate line of flume being used along up and down stream faces. Of course each time the flume was moved, it was necessary to establish a new connection at the point where it was fed from the supply flume. Sluicing was carried on practically continuously night and day, in order to save time, and the movable feature of the flume was considered to be a factor in the progress of the job. Sluicing Sand anu Gravel in Steel-Lined Flumes. Engineering Record, Dec. 20, 1913, gives the following account of hydraulick- ing at a gravel pit on Puget Sound near Tacoma, Wash., where the conditions of the plant are such, that an ordinary 1-in. board in the flume bottom will wear through in about two days, and the cost of maintaining any of the ordinary forms of flume block paving has proved prohibitive. The unusual severity of the wear is caused by the fact that the flume grades have been kept down 1024 HANDBOOK OF EARTH EXCAVATION to 8 and 10%, and about 1.6 cu. yd. of sharp material are car- ried for every 1,800 gal. of water pumped. The advantage of this is that a daily output of 1,800 cu. yd. is maintained with a pumping equipment which is considered comparatively light for the yardage handled. The deposit lies at the water's edge in a bank rising to an elevation of 240 ft. above mean low water, and all buildings, bunkers and loading dock are supported on piles in deep water. Flumes from the pit discharge into separators which feed a 500- cu. yd. gravel bunker and a 350-cu. yd. sand bunker. The bunkers discharge through twenty under-feed gates into 4-yd. bottom- dump cars which can be hauled to the end of the dock and emptied into scows at the rate of 6 cu. yd. per minute. Water is supplied to the pit from the Sound by two duplex compound steam pumps one with 10x16 and 12 x 18-in. cylinders, the other with 8 x 12 and 10 x 16-in. cylinders. From these pumps a 10-in.- riveted steel pipe line runs to the pit, paralleled by an 8-in. auxiliary line. The average lift of the water is 100 ft., and at this head these pumps normally deliver 1,800 gal. per minute. This delivery for 18 or 20 hr. per day is sufficient to bring to the bunkers the full capacity of 1,800 cu. yd. Three separators are in use, fed by three 130-ft., 12 x 12-in. flumes which branch from a main flume 24 in. wide and 12 in. deep. This main flume, which runs to the face of the pit, has a length of 100 ft. and is fed by numerous branch flumes of equal depth and 15 in. in width. From these branches 12 x 12-in. laterals are laid to attack the bank at any desired point. All these flumes in the pit are on an 8% grade, the three separator lines having a 10% grade. With the low velocity of water and the very heavy percentage of suspended matter the wear on the bottom of these flumes was so great that at first no material could be found which would fulfil the requirements of hardness and cheapness with a low coefficient of friction. Finally the expedient of buying old band- saws from the lumber mills was adopted, and the use of these saws to take the wear met with success, from the start. The flumes are built of 1 x 12-in. rough lumber, chiefly in (i-ft. sections, and this construction lends itself readily to the use of band-saws, which come in 10, 12 and 14-in. widths. In the 12 x 12-in. flumes a single saw blade is laid in the bottom and a three-cornered wooden strip nailed over it at the corners to hold it in place. In the 24-in. flume circular saw blades, sheared to the proper widths, were used in the same way. The band-saws are usually 12-gage, while the circular saws come in 6 or 8-gage thicknesses. As the material is oil-tempered HYDRAULIC EXCAVATION AND SLUICING 1025 tool steel, it is too hard to be recast successfully, and therefore has little scrape value. Discarded saws were bought at prices ranging from 0.25 to 0.50 ct. per pound and are believed to last three or four times as long in the flume as ordinary structural steel. In the flumes on 10% grade it is said that the 12-gage steel normally passes 10,000 to 12,000 cu. yd. of material before being worn out. Cost of Flumes. For detailed costs of flume construction, see the author's " Handbook of Cost Data." Cost of Gravel Mining. Data regarding the cost of hydraulic mining in California during the season commencing Nov., 1899, and ending July, 1900, are given by William H. Radford in Transactions, American Institute of Mining Engineers, vol. 31, 1901. During this season of 9 months 655,657 miner's inches ( 1 inch = 1,728 cu. ft. in 24 hr.) were used for the monitors and for sweeping the bed rock at the end of the season. This water cost delivered 0.69 ct. per miner's inch. Surveys showed the amount of material washed to be 1,251,399 cu. yd., or 1.9 cu. yd. per miner's inch. The banks varied in height from 50 to 130 ft., averaging 63 ft. The material consisted of pay gravel lying on pay rock and varying in thickness up to 8 ft., and barren top material con- sisting of broken rock, clay, soil, and gravel. The grade of the sluices was 7 in. in 12 ft. Long bed-rock cuts extended from the head of the sluices to the banks. These bed-rock cuts, in black slate, were constructed by hand drilling and blasting. Electric lights permitted night work. The ditch was 11 miles long and was cared for by 'two men during the rainy months and by one man for the remainder of the season. The cost of the hydraulicking was: Care of ditch, reservoir, siphon : Per cu. yd. Labor, $2,671; supplies, $116 $0.0022 Washing (piping), $2,401 0019 Drilling in bed-rock cuts: Hand, $1,051; electric, $270 0011 Timbering bed-rock cuts, $157 0001 Electric lighting, $599 0005 Sluice building and repairing: Labor, $1,046; supplies, $35 0009 Blacksmithing, $644 0005 Cleaning-up, $969 0008 Moving pipes and giants, $899 0007 Breaking rocks and clay, $6,125 0049 Clearing ground for piping, $158 0001 General expenses, watching sluices, misc., $3,089 0025 1026 HANDBOOK OF EARTH EXCAVATION Sluice building and repairing (continued) Per cu. yd. Supplies used in mine, $3,015 0024 Taxes, office expenses, legal expenses, surveying, sala- ries, $4,267 0034 Total, $27,512 $0.0220 This does not include interest or depreciation on plant. Methods of Working Placer Gravel. The following is given in Engineering News, Jan. 1, 1903. The mining property in ques- tion is in California and considerable capital has been expended there for the bringing in of water which is conducted to the mine by flume and ditch a total distance of 30 miles, having a capacity of 3,000 miners' inches. The nature of the ground through which the ditch is cut, the steep slope of the hillsides and the severity of the winters cause the expense of maintenance to be rather high, aggregating about 22% of the total exploita- tion expenses. During the earlier years of the company's exist- ence their water right, even in favorable seasons, never yielded over 450,000 miners' in. More recently, however, by advantageous reconstruction, this has been increased until from 650,000 to 750,000 miners' in. are obtained, according to the winter. This big supply of water a daily average of 3,000 miners' in. during eight months cannot be utilized constantly with profit in only one spot. For good work it is necessary to have several points of attack, thus allowing changes of water, moving of machines, clean up and other contingencies to be overcome without complete sus- pension of operations. Both mines consist of gold-bearing gravels, with material of every stee from pebbles to boulders of 2 to 3 cu. yd., requiring water, powder and derrick for their removal. , The bank is broken by four giants; one on the front with a head of 400 ft. and nozzle 7 to 9 in., according to circumstances; two on the left side with 150 to 250-ft. heads, and one on the right side with 500-ft. head, to break the cement. The gravels vary in thickness from 2 ft. to 250 ft., bearing gold throughout. Broken by the side giants, the bank is prevented from sliding too far by the front giant. The bank slides ahead as much as 100 ft. in 24 hr. The bank being for the most part loose, this sliding is, of course, caused by the piping. For this reason the entrance of the sluice is kept at a safe distance usually about 150 ft. away and the front giant always settled at the head of the sluice. The sluice is 6 ft. wide by 4} ft. deep, with the boxes 12 ft. long. At the beginning of the last mining season there were 56 boxes, and at the end of the run 118, of which additional number HYDRAULIC EXCAVATION AKD SLUICING 1027 14 were at the head and 48 at the lower end. The grade is 8 in. to the box (12 ft.). The bottom is laid with blocks in the first ten boxes and boulders in the others. Two undercurrents collect the fine gold very satisfactorily. It is estimated that between 2} and 3 cu. yd. were moved per miner's inch of water used, at a cost of 2.7 to 3.3 ct. per cu. yd. during the season 1901-02. A High Cost of Hydraulic Mining. In a paper published in Transactions, American Institute of Mining Engineers, vol. 33, 1903, W. E. Thome gives the detailed cost of a hydraulic mining operation at Georgetown, Calif. The cost of the material moved was 18.3 ct. per cu. yd. This high cost was due mainly to the short season, the expense of buying water, the cost of building dams to impound debris from " seam-diggings " located upstream, the hardness of the bed rock and resulting high cost of ground sluices, and the generally unfavorable situation. The bank varied from 7 to 23 ft. in depth. The bed sluices com- prised 1,300 ft. of 8-ft. wide sluices and 200 ft. of 4-ft. wide sluices, varying in depth from 4.5 to 25 ft. The grade of sluices was 1 in. in 12 ft. at the upper end to 4 in. at the lower end. Sluices, including the boxes, cost from $4 to $150 per lin. ft.! The water for ground sluices was obtained from a creek and amounted to 3,000 miners' inches continuing for 15 days of the year. The water for the giant was purchased at a cost of 0.5 ct. per hour per miners' inch. Through a 3-in. nozzle 200 miners' inches, under a head of 180 ft., were used. The average of ma- terial moved was 43.5 cu. yd. per hr. This low duty was due to the fact that the work was being carried up-stream. The costs of supplies were as follows: Lumber, $14 to $16 per M; powder, 12 to 13 ct. per Ib. ; fuse,- 50 to 55 ct. per 100; caps, 60 to 65 ct. per 100; iron, 3.5 ct. per Ib.; nails, 3.5 to 4.5 ct. per Ib. Miners received $2.50 per day of 10 hr. There were 7,500 cu. yd. of gravel moved at the following cost: Water $0.030 Labor 015 Debris dams 030 Moving pipe, etc 005 " Crevicing " and cleaning bedrock 006 Taxes, salaries, etc 007 Blacksmithing 003 Lumber 030 Labor on sluices 040 Powder, fuse, etc 017 Total per cu. yd $0.183 Methods and Cost in a B. C. Placer Mine. The following by Chester F. Lee and T. M. Daulton is taken from the Transactions of the American Institute of Mining Engineers, 1916, 1028 HANDBOOK OF EARTH EXCAVATION Ruby Creek is 8 miles long and flows in a southerly direction into Surprise Lake, British Columbia. The gravel being mined is about a mile up stream from the lake and is the stream bed or " creek gravel." The rock underlying the gravels is granitic and has taken its present form through glacial action, the al- luvial material having been deposited subsequently, partly by glacial and partly by stream action, in successive flows and at widely separated times as shown by a dike of basalt about 13 ft. thick which overlies the bedrock gravel on the east side of the creek. The gulch has steep banks and is about 250 ft. wide from rim CROSS SECTION Fig. 12. Cross-Section of Ruby Creek Showing Position of Gravels Being Worked by Hydraulicking. to rim at the surface of the gravel. The depth of the gravel at the center is 42 ft. Water. A log crib storage dam is situated 4 miles up Ruby Creek. It is 150 ft. long, 12 ft. high an 1 ft. wide at top, producing a reservoir % mile long and } mile wide with an average depth of 8 ft. From this the water follows the creek bed 3} miles to the intake, whence it flows into the ditch which is 8 ft. wide at the top, 4 ft. wide at the bottom and 3i ft. deep, the grade being 8 ft. to the mile. There are 400 ft. of ditch, then 300 ft. of flume across the gulch and 800 ft. of ditch to the pres- sure box, which is 8 by 10 by 10 ft. From this box issues the pipe line, 2,265 ft. long, beginning with 26-in. diameter 10-gage pipe, and ending with 16-in. 14-gage pipe. The normal flow is about 1,150 miners' inches (31 cu. ft. per second) which is used through 7-in. nozzles of No. 6 Hendy giants. Also 1,000 in. come down the creek and are used as a bywash to assist in handling the heavy material. The vertical head at the pit is 250 ft. Beside the main pipe line a 16-in. line tapering to 6 in. in a HYDRAULIC EXCAVATION AND SLUICING U029 rfiJ-r '- ! "i., i rir >' , \ -) v< 'T -\'\\-, rs'-rf *r *t l"' T ^i -'iiil- T*' *i_' > ni ' 'il length of 432 ft. is taken out of the pressure box and used on a Cassel impulse wheel of 25-in. diameter to actuate a Sullivan 8 by 8 class WG-3 belt-driven compressor the air from which is used to drill boulders. The sluices from the working pits are 42 in. wide by 42 in. high, set on a grade 4 in. to 12 ft. (2.77%). The sluices are double, as will be explained, and their length is 4,000 ft. Difficulties Overcome. The obstacles to be overcome in develop- ing and operating this property and the way they were surmounted make this operation noteworthy. The conditions which presented difficulties are outlined below: 1. The great width of the deposit, 250 ft., which with the 42-ft. banks made impossible the working as a single pit from rim to rim. 2. In May and June the flood waters produce four times as much water as can be used, and the excess water, if carried on top of the bank, tends to undermine it and cave it into the pit. 3. Only a small grade (about 3%) was available, which of- fered poor facilities for dumping. 4. The boulders were large in number and size. These problems were met as follows: The ground was divided by a median line up the creek into two series of pits, A on the west side and B on the east, each being about 125 ft. wide. See Fig. 12. Pit A was advanced 400 ft. first and then pit B. was begun, the pits being worked alternately. After hydraulicking some hours in pit A until the pit is so full of boulders that the stream is no logger effective, the water is turned off at the valve above the workings and two men are left there to block-hole and blast the boulders. Hydraulicking is then begun in pit B and continued until the boulders obstruct the work, when they are drilled and blasted in turn, and so on. The arrangement of sluices is such that in flood season, the excess water is allowed to flow over the face of pit A into the sluice at the bulkhead and down this to where the double sluices begin opposite pit B (Fig. 13). The gates at the head of the east sluice are closed and the flood waters go through the west sluice to waste. During the time of excess water, work in pit A is suspended, but pit B can be worked without interruption, save for the time needed to drill and shoot the boulders. Without these arrangements work would have to be suspended during high water, which would be a serious drawback as the season is only about 150 days in all. When the water recedes to the point that it can all be handled through the giant and by wash, hydrau- lieking is resumed in the pits alternately as above described. 1030 HANDBOOK OF EARTH EXCAVATION Only the east sluice is used for handling gravel and is fitted with gold-saving devices. The arrangement of gates, as shown in Fig. 13, permits the Fig. 13. Arrangement of Sluices, Details of Two-Way Gates; and Cross-Section of Gold-Saving Sluice. gravel from either pit to be sent down the east sluice; the west sluice is used only for excess water. The upper gate, shown in detail in Fig. 13, rests loosely against the post and is raised HYDRAULIC EXCAVATION AND SLUICING 1031 off the bottom of the sluice by two men throwing their weight on the end of the long lever. This relieves the water pressure and enables the gate to be thrown over. If it were not for this ar- rangment the pressure of the stream would make it impossible to move the gate. The gold-saving sluice boxes, 42 in. \ride, were originally paved with spruce blocks 8 by 8 by 10 in., spaced 2 in. apart longitudinally, but the excessive wear on them entailed frequent stoppages for renewals which was both annoying and expensive as the season is short and it is imperative to get the maximum use of the water during the open period. The steepest grade obtain- able was 3^%, which seriously limited the amount of gravel handled. In 1914, therefore, 2,400 lin. ft. of high-carbon steel plates (0.9% carbon) were bought from the Carbon Steel Co. of Pittsburgh and substituted for wood blocks for this distance. The grade of the flume was changed to 2.77% which gave 20 ft. ad- ditional dump at the lower end of the sluice. The plates cost $45 per ton at the mills, $108.80 per ton laid down on Ruby Creek. Plates of this sort were first used by The McKee Creek Mining Co. in this district in 1909. The plates are 12 ft. long, 38 in. wide, i/ in. thick, and are placed 2 in. apart as to their ends with a drop of } in. from one plate to the next. Fig. 13 shows how they are supported and held in position; 6- to 8-in. logs are sawed flat on two sides to a thickness of 4 in., and made } in, thicker on the downstream end than on the up- stream in each 12 ft. of length. The plates are supported by these and held down by the edges of the 3 by 10-in. lining boards. The space between plates makes an excellent riffle. The use of the plates increases the capacity of the sluice about 40% and enables angular pieces of blasted boulders 30 in. in their longest dimension to be put through as against 20-in. pieces with block riffles. Occasionally extra large boulders get into the sluice, and 5 by 2^-ft. boulders have gone through without trouble. All trouble from jammed sluices and overflows has thus been ob- viated. After a season's wear and carrying 67,940 cu. yd. of gravel, the plates showed an abrasion of ^ i n - At the end of the 1915 season, after transporting a total of 130,380 cu. yd., holes de- veloped at some points. The surface skin of the plates is harder than the interior and where the surface becomes slightly worn deterioration is more rapid. A steel equally hard throughout is desirable for this use and the question of its production has been taken up with the manufacturers. In 1915, 6,380 boulders were drilled and blasted and 21,955 "bulldozed" without drilling; in 1914, 23,832 were blasted, 1032 HANDBOOK OF EAllTH EXCAVAllOiN which, taking the two years together, is a boulder for each 2.5 yd. of gravel worked. The practice is to " bulldoze " the flatter and smaller boulders without drilling, and block-hole the larger ones and pipe all the pieces through the sluice. For drilling, iwo Sul- livan DA-19 40-lb. hammer drills are used with air pressure at 90 Ib. at the compressor % The air line is 2 in. in diameter and 1,000 ft. long ; two lines of 50-ft. hose y 2 in. in diameter connect directly with the drills. In 1915, explosives cost 26 ct. per boulder. In part of the ground an additional obstacle must be overcome. On the east side in pit B a dark basaltic dike about 13 ft. thick lies on top of the 21 ft. of pay gravel and is itself overlaid by 6 ft. of waste gravel. This basaltic flow is lenticular and thins out both in the upstream direction and from the center toward the east rim. It pinches out entirely 250 ft. upstream. Fortu- nately the basalt is friable and fairly soft, so .that by putting gopher holes under it and shaking up with powder it is gradually broken through, and can be washed away by ground sluicing and hydraulicking. In 1915 the following results were obtained: Average number of men employed 20 Hours piping in pay gravel 978 24 hr.-in. of water on pay gravel 46,862 Total cubic yards of gravel handled 62,440 Cubic yards per 24 hr.-inch 1.33 Cost per cubic yard of gravel handled: Labor $0.302 Explosives ' 0.119 Lumber 0.007 Stable 0.009 Hardware 0.006 Licenses and rentals 0.011 Liability insurance ,... 0.005 General expense 0.017 Total $0.476 The property belongs to the Placer Gold Mines Co. of Seattle; G. W. Fischer, President, T. M. Daulton, General Manager; the latter has planned the work and conducted the operations since the company took over the property from the original locators in 1908, and is still in charge. Range of Cost of Hydraulic Mining. There is a wide range in the cost of hydraulic mining. In a recently issued bulletin of the U. S. Bureau of Mines it is stated that the cost may range from 22/2 ct. per cu. yd. in California under exceptionally favorable circumstances to 12 ct. or even 20 ct. at Atlin, B. C., and to 25 ct. or more in Alaska, according to the conditions of operation. Where frozen gravel is encountered and where it is necessary to elevate the gravel, costs frequently exceed 60 ct. per cu. yd. The HYDRAULIC EXCAVATION AND SLUICING 1033 Bulletin gives data on work of this character from which the following has been abstracted by Engineering and Contracting, Oct. 18, 11)10. Hie first figures are for a hydraulic mine in Northern California. The season commenced in November, 1899, and ended the last of July, 1900. During this time, 655,657 miners' inches (an inch equals 1,728 cu. ft. in 24 hr.) of water were used for piping, and for sweeping the bedrock at the end of the season. From actual surveys, this amount of water washed down 1,251,399 cu. yd. of material, consisting of pay gravel lying on the bedrock, and vary- ing in thickness from a few inches to 8 ft., and practically barren top material, consisting of mountain slide, carrying considerable broken rock, clay and soil. The banks varied in height from 50 to 130 ft., the average height being 63 ft. The grade of the sluices was 7 in. in 12 ft., the boxes being paved with block rif- fles 12 in. deep. Long bedrock cuts extended from the heads of the sluices to within a few feet of the banks, and were kept prac- tically to grade as the work advanced. At first, electric drills were used on this work, but as it was found that heavy blasting shattered the rock too much, and caused slips, these drills were abandoned and hand drilling was substituted. The total cost ($27,512 for 1,251,400 cu. yd.) was made up as follows: Per cu. yd. Care of ditch, reservoir and siphon : Labor, $2,670 ; supplies, $115 $0.00223 Washing (piping) 00192 Drilling in bedrock cuts: Hand drilling, $1,050; electric, $-69 00105 Timbering bedrock cuts 00012 Electric lighting 00047 Sluice building and repairing: Labor, $1,045; sup- plies, $35 00086 Blacksmithing 00051 Cleaning up 00077 Moving pipes and giants 00071 Breaking rocks and clay 00490 Clearing ground for piping (cutting brush) 00012 General expenses, watching sluices and odd jobs . . . .00250 Supplies used in mine 00241 Taxes, office expenses, surveying, salaries 00341 Total per cu. yd $0.02198 The best known hydraulic mine in California, and the largest now operating in the world, is La Grange mine in Trinity County. The operating company now has a water system of 29 miles of main ditch, flume, tunnel, and siphon, 7 miles of 30-in. water-pipe line, and 14 miles of auxiliary ditch not now in use. This is sup- plied with all necessary reservoirs and connections for bringing the water to the face of the pit, and with the dam at the lower lake represents an outlay of approximately $700,000. Twenty-eight 1034 HANDBOOK OP EARTH EXCAVATION men, including the boarding-house force, are employed at the mine. The method of operating is as follows: Water is brought from the mine reservoirs in two 30-in. pipe lines and discharged against the gravel bank through giants under a head of 600 ft. Either two 8-in. or one 8-in. and two 6-in. nozzles are used at one time. These combinations require 4,000 to 4,200 miners' inches of water, and they usually empty the mine reservoirs in six hours. The water is then shut off from the pipes and the reservoirs are al- lowed to fill, requiring generally four hours when the full head of water is in the ditch: during this time the pipe men drill and blast the large boulders and hard pieces of cement rock in the pit. Boulders of 1 ton and 2 tons' weight at times pass through the sluice, though such large boulders are generally blasted in order to save water. The cemented gravel is disintegrated usu- ally before it leaves the pit, and little or none is found on the dump. At the usual rate of operation, the pipes wash down and send to the sluice 1,000 cu. yd. of material per hour. The sluice box is 6 ft. wide by 5 ft. deep and is lined with 40-lb. steel rails set transversely 5 in. apart on the bottom and longitudinally on the side and held in place by lugs and bolts. Quicksilver is sprinkled in the upper part of the sluice every few days. The sluice is 2,400 ft. long. The great length of sluice is necessary to carry the tailings to the edge of the dump. At 1,300 ft. it branches into two parts in order to distribute the de"bris over the width of Oregon Gulch. Each year it is necessary to add about 50 ft. to the lower end of each branch. The amount added to the upper end varies with the slope of the bedrock and the movement of the gravel mass. Working costs vary for different seasons from, 2.8 to 3.5 ct. per cu. yd., the percentage of cost being distributed approximately as follows: Per cent. Maintaining ditch 18 Washing, gravel piping 9 Sluice maintenance 25 Breaking bowlders '. 9 Pipe lines and giants 7^ Roads and buildings 3* Clean-ups 1 Administration 8^ Taxes Teaming 5 Boarding house 8 Various 2% The following data, including average operating costs, relate to hydraulic mining at Atlin, B. C., for the seasons 1910 to 1913: HYDRAULIC EXCAVATION AND SLUICING 1035 Pitl Pit 2 Possible running time, days per season .... 184 180 Actual running time, days per season 154 141 Cubic yards worked per season 283,300 178,580 Cubic yards per day per season 1,540 992 Cubic yards per day for time running .... 1,840 1,266 Miners' inches used per day 4,500 4,250 Yards per inch per day of running time . . . 0.41 0.30 Average depth of ground, ft 60^ 16% Average cost per cubic yards, cents.f Pit 1 Pit 2 Labor 7.34 13:29 Powder 1.40 1.96 General operations 2.18 3.03 Ditch maintenance .22 .35 General expense .44 .70 Royalties, rental, etc 49 .64 Total, ct. per cu. yd 12.07 20.01 t Boarding house included in labor. " General operations " includes supplies, teamsters, blacksmiths and 9ther operat- ing expense not directly chargeable to either pit. " General expense " includes traveling, offices, etc. Costs of working gravel banks with water under pressure and elevating the material with hydraulic elevators will vary greatly in different localities. The following data concern hydraulic min- ing at the River Bend mine. The River Bend mine is on the Klamath River, Siskiyou County, Cal. The water is obtained from two sources; one ditch supplies the water for the giant, the other for the elevators. The supply system includes 11 miles of ditches and 1^ miles of flume. There are two Joshua Hendy giants with 3^-in. nozzles, which consume about 525 cu. ft. per minute working at an effective head of 90 to 100 ft. A Campbell hydraulic elevator having a 10^-in. throat and using approximately 560 cu. ft. of water per minute under an effective head of 325 ft. raises the material 40 ft. ver- tically. The elevator is set in a sump 10 ft. deep and at an in- clination of 70, the height of the gravel bank being 30 ft. The following table is made from daily averages throughout the season of 1912-13. The working costs do not include administra- tion charges. ' ;-n- offf !o-i>ml)rf;-r -iiljuri {>''/!{ i'>l I** I m fo&taHTtB Cubic yards of gravel washed per day 417 Cubic feet of water used per minute for giants 525 Cubic feet of water used per minute for elevator 560 Cubic feet of gravel lifted per minute 7.81 Cubic yards of gravel washed per miner's inch (giant) water 1.19 Grade of sluice, inches in 12 feet 7 Operating cost per cubic yard, not including admin- tration, cents 8 At the Logan mine, near Waldo, Ore., with 40 cu. ft. of water a second, 15,000 to 30,000 cu. yd. of gravel are washed per month. 1036 HANDBOOK OF EARTH EXCAVATION Four giants are used, two in the pit and two on the tailings dump. A 20-in. hydraulic elevator with two lifts elevates the material 41) ft. The gravel is easily washed, there are no large boulders, and the operating expenses are said to be only 3% ct. per cu. yd. under exceedingly favorable conditions. Hydraulic Elevators. A hydraulic elevator is an " ejector " used to raise water and gravel. An ample supply of water and proper means for rejecting large stones, lumps of clay and debris are essential. Elevators are generally arranged in a sump cut in the bed- rock, and the gravel from the monitors is washed to this sump through a ground sluice. The elevators pick up the gravel and water and raise it from the sump to the ground sluice. Large boulders can be left in place and the bedrock around them cleaned with a small hand nozzle. Hydraulic elevators consist of a tube into which a jet of water is introduced under pressure. The velocity of the moving jet of water acts on a larger body of water and gravel introduced at the suction end of the tube and causes it to be discharged at the other end. Grading River Banks with a Water Jet. The following de- scription of grading a sandy river bank is given by Taro Tsuji in Engineering Xeu's, Feb. 6, 1892. The bank, 12 to 17 ft. high above low water, was graded to a slope of 2 horizontal to 1 vertical. The plant used was a 40-hp. boiler and a simple duplex plunger pump, with a stroke of 10 in., and a diameter of 5^4 in., mounted on a barge. The water was pumped from the river and delivered through a 2i-in. hose. The jet, varying in amount from 230 to 260 gal. per min., under a pressure of 140 Ib. per sq. in., was played upon the bank. The earth was removed at the rate of 35 to 40 cu. yd. per hr., using 10 Ib. of coal per cu. yd. This method was economical but left the bank in a rough con- dition. The earth was dressed by pick and shovel. H. St. L. Coppee, in Transactions of the American Society of Civil Engineers, Vol. 35, July, 1806, describes another plant con- structed in 1881 for hydraulic grading of the river banks on the Mississippi. A fire pump with 161/^x 18-in. cylinders and 9-in. water plungers, having two 4-in. discharge pipes, and a 42-in. x 24-f t. boiler, were placed on a barge, 16 ft. wide by 98 ft. long by 3.5 ft. deep. The total cost of the plant was $3,679. This plant was not used. In sluicing the bank a trench was first cut with a shovel to the required angle of slope, and in it was placed a continuous line of wooden boxes to form a trough from the top of the bank to the HYDRAULIC EXCAVATION AND SLUICING 1037 water surface. A pump used for sinking piles with a water jet and mounted on a pile-driver barge, was moored near the trough and supplied its upper end with water. Earth was excavated and thrown into the trough by shovels, the water carrying to the river. This method was abandoned for work on a larger scale, the water being used to wash out the bank. The grader used in 1882 consisted of a barge 110 ft. long by 30 ft. wide by 6 ft. deep. The pump was a Blake compound con- densing, with double plungers each 16 x 24 in. The steam cyl- inders were 18 and 30 in. in diameter by 24-in. stroke. The capacity was 2,000 gal. per min. with a pump pressure of 160 Ib. and a steam pressure of 80 Ib. per sq. in. Steam was obtained from three boilers, 42 in. by 26 in. in size. The pumps discharged into a 14-in. boom pipe having twelve 4-in. openings, from which lengths of 2^-in. rubber hose lead. The nozzles were 1% in. in diameter. In operation the boat was moored to the bank and the hose lead to within 8 ft. of a guide face cut in the bank. The nozzles, mounted on swivels, were each worked by three men. The slope was cut a little ahead at the upper end; the reason being that the water after discharging against the bank, ran close to the lower edge of the face, helping to undercut it. A 4-in. hose and a 1^4-in. nozzle gave the best results. Banks were graded to a slope of 2}4 to 1. Sand and light deposits were easily graded, but clay and " buckshot " resisted the jet for some time. With 3 nozzles an average of 1,300 cu. yd. was removed per day at a cost of about 4 ct. per cu. yd. Trimming was done by hand shovels. At Bullerton in 1883, grading cost 3 to 3.8 ct. per cu. yd., 3 men being employed to each nozzle. At Plum Point 1,800 to 4,000 cu. yd. were moved per day at a cost of 3 ct. per cu. yd. In sand at Lake Providence Reach grading cost 2% to 3} ct. per cu. yd. The engineer in charge estimated from daily ob- servations continued over a month that to excavate 1 cu. yd. of earth required a fraction less than 1 cu. yd. of water, under a pressure of 140 Ib., with steam pressure at 80 Ib. and a vacuum of 26.5 in. With steam pressure at 80 Ib. it required 3 Ib. of coal per cu. yd. of water thrown or earth removed. Shovel grad- ing cost 30 ct. per cu. yd. At New Madrid in 1893 grading to a 3 to 1 slope cost 3.8 ct. per cu. yd. Mr. Coppee gives the cost of a typical hydraulic grading plant with all hose and fixtures at $20,000. Of work done in 1889 on the Missouri River for the Chicago & Alton Ry., W. R. De Witt in Engineering News, June 5, 1902, 1038 HANDBOOK OF EARTH EXCAVATION states that a grading force of 1 engineman, 1 fireman, 1 watch- man, 1 nozzleman, and 2 laborers graded 100 lin. ft. of bank or 800 cu. yd. of earth in a 10-hr, day, under average conditions of soil and velocity of current. Labor cost $10.25 per lin. ft. of revetment or 1.28 ct. per cu. yd., and fuel and engineman's supplies cost $2.25 per lin. ft. of revetment or 0.28 ct. per cu. yd., a total of $12.50 per lin. ft. or 1.56 ct. per cu. yd. According to Engineering News, May 9, 1907, at about 40 miles below St. Louis 3,444 cu. yd. were removed by hydraulic jets, and 44 cu. yd. were surfaced by hand. The total cost was 2.5 ct. per cu. yd. ' \ D. J. Whittemore gives the cost per cubic yard of grading a bluff on the Missouri River as 1 ct. for powder plus 1.5 ct. for labor and other supplies. The bluff was 100 to 180 ft. high and it was dangerous to employ the water jet without having at all times complete control of avalanches. This was secured by blast- ing down the bank after it had been partially undercut by the jet. According to Engineering News, July 29, 1915, to clear the river channel of the Kaw River, Kansas, during high water, about 10,- 000 to 15,000 cu. yd. of earth near the east span of the Union Pacific Bridge was removed in a very short time. This work was accomplished by a gang of eight men, drilling and shooting the dirt, using just enough 40% dynamite to allow it to be broken up thoroughly. As soon as a shot had been set off at one end, a fire hose, with a 1^-in. nozzle, and about 80 Ib. nozzle pressure, was utilized to wash the loose earth into the swift current of the river. Water was furnished by a fire engine at the end of about 1,000 ft. of hose. The river current was flowing at the rate of about 8 to 10 ft. per second, and the large pieces of excavation detached by the jet of water were quickly washed down stream by the current. The entire amount was removed in about two days' time at a very low cost. Stripping Gravel Pits by Hydraulic Methods. The following is an abstract of an article by W. H. Wilms in the Railway Age Gazette, June 18, 1915. During the past ten years there has been a rapid increase in the use of the hydraulic method of earth removal. Engineers are just beginning to appreciate the possibilities of this method of excavation, and the next decade will undoubtedly witness a still greater development and growth in hydraulic excavation. The filling of trestles on the Northern Pacific and the Canadian Pacific at a cost of from 4 to 13 ct. per cubic yard; the re- moval of 34,000,000 yd. of material in the regrading of Seattle, Wash.; the hydraulic construction of large embankments on the HYDRAULIC EXCAVATION AND SLUICING 1030 Pacific coast extension of the Chicago, Milwaukee and St. Paul; and the more recent construction of the Fernando dam of the Los Angeles aqueduct, where about 2,000,000 yd. of earth were sluiced at a total cost of 7 ct. per yard are recent examples. The remarkable results obtained in these cases seem to be little realized or appreciated by many engineers unacquainted with this class of work. A comparatively large field for this method of earth ex- cavation is in stripping the overburden of gravel ballast pits and stone quarries. Conditions about a gravel pit are quite often favorable to the hydraulic method of stripping. The soil is generally a loam or soft clay that can be handled very ef- fectively with water. A great many gravel deposits are either very close to a stream or river or underlaid with water, an ample supply of water thus being assured. The sluiced ma- terial can" also be dumped in many cases into the abandoned or worked-out portions of the pit. Where this is possible, ample dumping grounds and sufficient grades for the flumes are gen- erally assured. If the stripping is shallow, not exceeding 3 ft. in depth, and a large daily output or yardage is desired, the hy- draulic method should be adopted with a great deal of caution. Duty of the Water and Size of Installation. The amount of water necessary to move one cubic yard of material depends upon the grade of the flumes, the character of the material and to a more or less extent upon the pressure of water available. The quantity of water is of more importance than the pressure. Com- paratively light grades can be used for the flumes if a sufficient quantity of water is present to effect complete suspension. Clay requires more water, greater pressure and greater flume grades to handle than ordinary loam or dirt. The amount and size of rocks, if any, also affects appreciably the duty or carrying ca- pacity of the water. It may be said, however, that as a mini- mum, with ordinary loam or soft clay and flume grades of 7 to 9%, 10 cu. yd. of water are required to move 1 cu. yd. of ma- terial. As a basis for an estimate, however, it is generally not advisable to depend upon a greater percentage of spoil than 15% for loam or dirt with the usual flume grades of 7 to 9%. For soft clay and heavy, sticky loam, 10 to 12% can be considered a safe estimate where 7 to 9% grades can be obtained. The above duties are based upon a flow of 1,000 gal. per min., which is the minimum discharge advisable for hydraulicking. In stripping gravel deposits a considerable amount of water is lost by flowing down into the gravel, which must often be considered in estimating the necessary water supply. If the top stratum of the gravel deposit is a sand or compact gravel, this 1040 HANDBOOK OF EARTH EXCAVATION loss is generally insignificant, amounting to only 2 or 3*# . If,, however, the top stratum is a coarse, loose gravel, the loss from this source may be as high as 10%. A pressure of from 40 to 60 Ib. per sq. in. at the noz/.le is usually sufficient for the sluicing of loam or dirt. For soft clay and some heavy loams, 60 to 80 Ib. pressure is usually required. A pump having a capacity less than 1,000 gal. per min. should not be installed. A 1,500-gal. discharge would be more efficient, and for the ordinary installation is to be preferred. With such a discharge, using two nozzles, and with favorable grades, it should be possible to sluice from 450 to 700 cu. yd. of material per day of 10 hr. A crew ordinarily required for such an instal lation consists of one pumper or engineman ; two pipemen ; one assistant to the pipemen; three laborers and a foreman tearing down and erecting flumes; and one laborer on the dump. Flumes. The water supply, the character of the overburden and the fall available to the dump determine the grades of the flumes. In the stripping of gravel pits where the excavated space is used as a dumping ground, ample grades for the flumes are generally assured. Full advantage, however, should be taken of all the fall available, a difference of only 1% in the grade of Jhe flume effecting a great difference in the carrying capacity or duty of the water. Where the available fall makes necessary the use of low flume grades much larger quantities of water are required to effect complete suspension of the material. For stripping, grades lower than 6% should not be used. Where 3% and 4% are the maximum that can be used, the quantity of water necessary for the operation of such low grades is so great that hydraulicking fails to show any great economy over other methods. While it is true that grades as low as 3 and 4% are often used in large hydraulic mining operations, it should be re- membered that in such operations the flume grades must be kept comparatively low, so that the velocity of the water will not be so great as to prevent the gold from settling in the riffles in the bottom of the flume. The object here is to use sufficient water to transport the gold bearing gravel and flume grades that will not cause excessive velocities. It is because of this fact that the carrying capacity of water in hydraulic mining is very low, the material excavated amounting to only about 2 to 6% of the water used. Where conditions will permit, the flume grade should be at least 7%; 8 to 10% grades with an abundant supply of water are considered very satisfactory grades, and are usually obtain- able in stripping operations where the material is sluiced into the worked-out portions of the pit. These remarks apply only to HYDRAULIC EXCAVATION AND SLUICING 1041 box flumes. Where ground sluices are used considerably heavier grades must be used, as they are very likely to become clogged up from roots, gravel, sticks and pieces of sod. In such cases use flume boxes in these open sluices as shown in Fig. 15-8. The 12' ron. 3ide View. Angle iron' 1 Section. Pressure tine. $Ecfge ofstr/pp/ng. Hose connections) t-Edge of stripping. Stripped. Top ofs/ope.~i V----3 - i I'lWI'll Flume. *| I'lWI'lW f Bottom of & /ope. Main pressure tine.-? Fig. 14. Flume Construction for Stripping Gravel Pits. Sketches 1-4. time required to place them will be but a fraction of that lost in continually cleaning out the open ditch. Flume grades should be made as uniform as possible. A slight break in the grade will often cause clogging, especially if a sandy loam is being handled. Abrupt changes in the alinement of the 1042 HANDBOOK OF EARTH EXCAVATION rTT^r Levee of earth or grareF/ Grovel IZ , 7^\ backed up with brush. Pipe drain. boards. -4'fo7' -J \; <4'to7' \ Pressure //r/e.-j . *ctyt of stripping. Area stripped. mnmum. I {-Top of slope f Bottom of slope. 3'. ZFcfye I ^Ground JS/uice begins here. Sfr 'PP in 9- W/ng or deflector board. ^ \rWing. 4' yfs/ope Plan. of stripping. rr 3\ Ground sluices /n* ^ > T-Top of slope) which f/ume boxes VJ Flume.- -Flume. <^ MA Gravel. Section. Fig. 15. Flume Construction for Stripping Gravel Pits. Sketches 5 to 8. HYDRAULIC EXCAVATION AND SLUICING 1043 flumes are best made by making a break or drop in the flume grade. Sand requires heavy grades and shallow sluices. Wide, shal- low sluices should be used where the grades are light. If the overburden contains many stones and boulders deep, narrow sluices should be used. In this case, the depth of the water in the flume should be equal to the width of the flume. The width and depth of flumes depends largely upon the character of the materials as well as the water supply. The rectangular section for flumes is generally to be pre- ferred to the semi-circular or elliptical section. A large amount of the material carried by the water travels or rolls on the bot- tom of the flume. Where the circular section has been used the wear on the flume has been confined to a relatively small area in the lowest part of the section. Where stones or gritty ma- terial are present in the overburden this wear becomes excessive, the metal wearing through and becoming full of holes in a very short time. With the square or rectangular section, how- ever, the wear is quite evenly distributed over the bottom, re- sulting in a much longer life of the flume. In order that the flumes may be easily and quickly erected and taken down they should be built in^ sections or boxes from 10 to 12 ft. long. Both wooden and mental flumes are used. Wooden flume boxes have proven very unsatisfactory for strip- ping service, as they quickly become water soaked and heavy, and when dried out, check and split badly. Moreover, in the constant nhandling of the flume boxes, they go to pieces very soon. In stripping, flumes are changed many times and a flume box should be built that will not only stand the excessive wear and abrasion of the material being carried, but the rough and constant handling as well. For this service the metal flume is probably the best suited. Fig. 14-1 is a sketch of a steel box flume that has given very good service. This flume is constructed of No. 14 gage steel, and is made in sections 12 ft. long. It sometimes becomes necessary to carry the sluiceway or flume through an intervening ridge to obtain a dumping ground for the sluiced material. If the tunnel has a heavy grade, vitrified sewer pipe will prove satisfactory. If the grade is light, however, any slight settlement of the pipe joints is liable to cause clogging. Under such conditions riveted steel pipe in lengths of 20 ft. or more has given very satisfactory results. Pipe No. 16 to No. 14 gage steel has been used for this purpose. Stripping Shale in Illinois. The shale ledge worked by the Western Brick Co., of Danville, 111., is covered with from 3 to 6 ft. of loamy sand and gravel, which is stripped and carried away by 1044 HANDBOOK OF EARTH EXCAVATION means of hydraulic giants at a cost of about 2 ct. per cu. yd. From information furnished by F. W. Butterworth, the general manager of the company, the following description of the plant and of the methods of operation is given by Engineering and Contracting, Aug. 15, 1906. Water is brought to the giants from the pumping station through a 10-in. pipe which is now about 4,000 ft. long. This pipe is kept extended to a point somewhere near the bank where it is tapped with two 4-in. pipe connections which extend to within from 20 ft. to 50 ft. of the working face and end in 4-in. hose carrying 2^-in. nozzles. The nozzles are fitted with adjustable needle points, which permit a variation from y 2 in. to li in. in the stream. The pressure at the nozzle is normally 75 Ib. per sq. in., but it may be doubled when desired. The water is fur- nished by a compound duplex Smith-Vaile steam pump, with a 16-in. water end and 16 : in. and 24-in. steam ends. The pump is located on the bank of the Vermillion River, which passes through the shale bed, and it takes steam from a 72-in. x 16-ft. tubular boiler located in a house on the crest of the river bank and some distance away. Because of the separate boiler and en- gine houses a fireman and engineer are required; were the en- gine and boiler in one building the engineer could do his own firing. It is to be noted further that the steam connections are so arranged that live steam can be turned into the low pressure cylinder; this enables the water pressure to be jumped up to 150 Ib. per sq. in. at the nozzle when hard material is encoun- tered. Normally the pump pressure is kept at 115 Ib. Two giants are worked, each operated by one man, and there are in addition a fireman and an engineer, making a labor force of four men in all. These men get $2 per 10-hr, day. On the aver- age about 2,000 cu. yd. are moved every 10 hr. This gives a labor cost of 0.4 ct. per cu. yd. for excavating and transporting. The material is carried away in sluices, and it has been found easily possible to handle it 1,600 ft. in this manner on grades of 3%. Including costs of pumping, sluices, etc., the total cost has not exceeded 2 ct. per cu. yd. moved during the four years that the process has been used. The cost of stripping is made more expensive than ordinary excavation owing to the fact that the shale has to be perfectly cleaned by holding the stream on it after the earth has been practically all removed. Stripping Shale in Iowa. Engineering and Contracting, Apr. 19, 1911, gives the following: The shale pit is about 1,800 ft. from the Raccoon River in Des Moines, la. The nearest building of the plant itself to the shale HYDRAULIC EXCAVATION AND SLUICING 1045 pit is the pan room, 150 ft. away. The pan room floor is 9 ft. above the floor of the pit. There is no place near the pit to which the over-burden might be moved, and it became necessary to de- vise a scheme for carrying the material some 1,100 or 1,200 ft. to a tract of low ground. The hydraulic plant consists of a 14 and 20, 101/4 x 15, Worth- ington compound duplex outside packed plunger pump, steam for which is furnished by a 75-hp. horizontal fire tubular boiler. The pump has 8-in. suction, 7-in. discharge, 2i-in. exhaust steam, and 5-in. exhaust. At the entrance to the pump the suction line carries a vacuum chamber 12 ft. high, 8 in. in diameter, with a vacuum gage. The pump is operated at 40 revolutions per min- ute (80 Ib. steam). That portion of the 8-in. line which runs between the river and river bank is carried on two floats and is connected to the line at the river bank by a rubber sleeve se- curely clamped. The 7-in. discharge line carries a gate valve at the pump and a pressure gage. Two leads of hose are carried from 5-in. line by a Siamese con- nection. Each lead is operated by one man. This is possible by reason of a standard to which the play pipe is rigidly at- tached, and which is susceptible of both a vertical and hori/ontal motion. Each lead of hose terminates in a ~/ 8 in. nozzle. The 6-in. spiral pipe is connected to a 6 to 12-in. spiral in- creaser, flat on the bottom. Above this increaser are three 10-ft. lengths of 12-in. spiral pipe, which afford a reservoir to the 6-in. spiral pipe. The spiral pipe is susceptible of easy bends. There are two 45 ells in the spiral pipe line. The spiral pipe is car- ried through a 12-in. cast iron pipe under the C. G. W. tracks. The cast iron pipe terminates in three lengths of 12-in. sewer pipef The pump-house was located about 655 ft. from the river bank, and so planned that the lift from the river would amount to less than 18 ft. at extreme low water. It was decided to install a pump sufficiently large to handle the requisite amount of water without injury to the pump, at the same time insuring fuel economy. The difficult problem, of course, was the determination of the character of sluiceway which would carry away the ma- terial from the pit and place it. For only a short distance could the sluiceway be carried above ground. An experimental line of 12-in. sewer pipe was tried with much misgiving. True to prophecy, it was impracticable, requiring long periods of flushing, and thus reducing the efficiency of the plant in that only a small amount of stripping could be done in a day. This line was one already in place, it being used as a 1046 HANDBOOK OF EARTH EXCAVATION drainage sewer to carry off storm water, drips, etc., from the pit and from the plant. The sewer line could dispose of clay or earth in solution or gravel, but it was absolutely impracticable in the disposition of sand. The sand would settle to the bottom of the pipe, requiring hours to remove it. Because of the large proportion of sand in the overburden, much more than is apparent from a casual observation, it be- came necessary to devise a sluiceway which would insure greater velocity to the effluent and at the same time agitate the sand dur- ing its flow. A 6-in. spiral pipe line was decided upon and in- stalled. It works splendidly. This line has become clogged only twice. The plant has been in operation since May 1, and since that time to Nov. 1 there has been moved about 50,000 cu. yd. of overburden. The following are the principal data relating to the pipe lines : 8-in. Suction Line: Elevation extreme low water 80.0 Elevation bottom 8-in. pipe at intersection with pump house 93.66 Elevation top of pump foundation 97.1 Elevation entrance to pump 97.6 Extreme total lift <>f suction 17.6 Length of suction line from pump to river bank (ft.) 655 Total length of line (ft.) 690 Grade from piimp house to river bank (per cent.)... 1.67 7-in. Discharge Line (Water Line) : Total present length (ft.) 1,080 Elevation at pump 100.75 Elevation at discharge 161.0 Total lift of discharge 60.25 6-in. Spiral Pipe (Hydraulic Sewer) : Total present length ((ft.) 1.090 Elevation of intake (station 1,065) 140 Elevation of station 729 '. 109.67 Elevation of station 375 (45 bend) 103.6 Elevation of station 025 (45 bend) 101.45 Elevation of station 000 (outlet) 101.25 The work accomplished and its cost were as follows : Total volume of water per minute at 20 complete revolutions of each piston rod equals 428.8 gal. Total volume per day of 9 hr. equals 231,552 gal., equals 1,146.6 yd. Total effluent per day equals 1,432.5 cu. yd. Of this, conservatively, 2Q% is solid material, thus giving 286.5 cu. yd. overburden disposed of per day of 9 hr. Samples of effluent are taken every hour and percentage measured. Boiler fireman $2.25 Man at intake 1.50 One man at nozzle 2.00 One man at nozzle 1.80 Total labor per day $7.55 HYDRAULIC EXCAVATION AND SLUICING 1047 Fuel, 1V 2 tons, at $1.50 $2.25 Oil 0.15 Maintenance and supplies, including hose, new pipe, etc 0.85 Total cost per day $10.80 At 286.5 cu. yd. per day, it follows that the cost of stripping and placing is about 3% ct. per cu. yd. Stripping a Quarry. The following data are given in Engi- neering and Contracting, Mar. 1, 1911, regarding the method used for stripping the limestone rock at the quarry of the Mathews Stone Co., Bloomington, 111. The depth of quarry stone being 25 ft. an area is cleared suf- Fig. 16. Glazier Turret Nozzle Hydraulic Monitor. ficient for a season's work, the overlying soil being each year washed into the quarry pit left by the previous season's work. To keep the new and old pits separate a dividing wall of rock is left unquarried. The floor area of the pits is about 100x120 ft. The equipment employed consists of a 100 lip. boiler deliver- -ing steam at 100 Ib. pressure to a compound duplex pump having 10xl2-in. and 12 x 18-in. steam cylinders and 12 x 18-in. water cylinders, and of 7 -in. pipe reduced to 4 in., with 4-in. flexible joints and a Glazier turret nozzle, Fig. 16. -;*>T In front of the quarry floor is a large hole, 30 ft. deep, and 120 by 150 ft. in extent. The overburden of the quarry is washed 1048 HANDBOOK OF EARTH EXCAVATION into this hole by water from the hydraulic monitor. The water then overflows into another hole, arid at this point the pump is located. r Jhe monitor is operated at a point about 10 ft. from the edge of the earth, one man being required. The water is directed so as to undercut the bank, and wash the earth to the sump. At the same time the seams of the rock are cleaned, and after a floor has been quarried off, the debris, such as spalls and dirt, is washed off also. The earth is hard red clay, of such a nature as to require picking for hand excavation. The over- burden is removed in strips 10 ft. wide. When the monitor is moved, the pump is shut down and the engineman helps to relo- cate the monitor. The cost of operation is the cost of the wages of three men, and the cost of coal and oil. Removing a Land Slide by Hydraulic Jetting. The following is given by W. G. Curt in Trans. Am. 8oc. C. E., vol. 24. A land slip blocked the mouth of a tunnel on the Southern Pa- cific R. R. in California. The slide was almost entirely removed by wheelbarrows in 5,500 man-days of 1 1 hr. each, when another heavy rain and snow storm caused a second slide of as large a quantity as the first. Falling stones and earth and the soft na- ture of the material prevented a further use of wheelbarrows and the material was removed with a hydraulic jet. Twelve ordinary standard " surface " steam pumps in a gang discharged 3,300 gal. per min. (16.5 cu. yd.). They were set in a line 100 ft. from the river and 15 ft. above it. Steam was supplied by 3 locomotives. The discharges led into a 12-in. pipe, one end of which was connected to a circular air chamber 60 in. diameter by 06 in. high. This gave a steady stream. From the air chamber sheet iron pipe (No. 12 Birmingham gage) in 30-ft. sections, carried the water to the monitor. The ends of the pipe were slid into one another and pushed tight, or " stove- piped." The giant was fitted with a 3 or 4-in. nozzle, according to the nature of the material. The material was carried in wooden sluices to the river. In 9 days 9,000 cu. yd. were moved at the rate of 1,000 cu. yd. per day of 24 hr. The water required was about 2,000 gal. per min. (10 cu. yd.) at a pressure of 45 to 50 Ib. Each miner's inch (1,728 cu. ft. or 64 cu. yd. in 24 hr.) moved 5 cu. yd. This is somewhat less water than is required in mining operations. The cost was as follows per 24-hr, day: 25 cords of wood at $3 $ 75 8 firemen and pumpers 20 Machinists and repairers 25 Men operating giant (high wages) 20 30 laborers 50 Total at 20 ct. per cu. yd $200 HYDRAULIC EXCAVATION AND SLUICING 1049 A steam shovel could not have been used economically, both because of the danger from falling rocks and because of the lack of room for switching cars. Methods and Cost of Hydraulicking on the Panama Canal. Engineering and Contracting, Mar. 1, 1911, gives the following: The channel of the Panama Canal for a length of about 1^ miles south of the Miraflores Locks requires the excavation of about 1,500,000 cu. yd. of rock covered with 8,158,000 cu. yd. of earth. To remove these materials by dredging and subaqueous rock excavating methods would necessitate a plant of such size that it could not be assembled for some time and would be very costly. Investigation indicated that once the rock were cleared of its earth overburden it could be excavated more rapidly by steam shovels than in any other way. Steam shovel plant was not available, however, to strip off the earth as rapidly as the progress required demanded, and, moreover, the swampy nature of the earth made it certain that the maintenance of tracks would be difficult and expensive. To meet the conditions most cheaply and^ expeditiously it was decided to remove the overburden by hydraulicking and pumping, and then excavate the rock in the dry by steam shovels. By the method of excavation indicated for removing the over- burden two principal operations were involved: (1) disinte- grating the material and washing it to sumps by means of water jets under high pressure; (2) lifting ^and conveying the loosened material through flumes by means of dredging pumps. The plant required, therefore, consisted of ( 1 ) a central pumping station, (2) pipe lines and hydraulic monitors and (3) dredging pumps. A portion of the area to be excavated was originally occupied by the bed of the Rio Grande. The river w^as diverted and a dike built across the south end to prevent the tide water from flowing up the old bed. Upon the completion of the dike the water remaining in the inclosure was pumped out until just enough remained to float the barges in the lowest places. The giants were operated in the immediate vicinity of the barges so as to lower them to bed rock, thus forming a sump for the suc- tions of each dredging pump. The regular operation of under- cutting and washing the material to the dredging pumps by means of the monitors was begun, the cutting being extended until there was sufficient slope to sluice the material to the dredg- ing units; the water would then be allowed to rise high enough to float the barges to new positions. During the three months up to Jan. 1, 1911, that the plant described was in operation the amount of excavation was 156,125 cu. yd. and its cost was as follows: 1050 HANDBOOK OF EARTH EXCAVATION Ct. Pumping station 12.5 Pipe lines 5.5 Dredging pumps 8.2 Relay pumps 0.5 Dykes 0.3 Maintenance of equipment 8.2 Power 25.2 Plant arbitrary 5.0 Division expense 1.4 Total division cost 66.7 Administration and general expenses 4.6 Total per cu. yd 71.3 Excavating a Canal by Hydraulicking. At Seattle, Wash., part of the waterway for a canal was excavated with a hydraulic monitor. The canal was designed to have a length of about 2 miles, a width at bottom of GO ft. and at low water mark of 140 ft., arid a minimum depth of 35 ft. The following details of the work were given by C. H. Rollins in a paper read before the Pacific Northwest Society of Engineers, abstracted in Engi- neering Record, Nov. 12, 1904. The water was obtained from a reservoir belonging to* the city waterworks system, about a mile distant. The available head varied from 190 to 250 ft. Wood-stave pipes, 30 and 18 in. in diameter, and a 15-in. steel pipe at the end, were used for conveying the water to the monitor. The material removed was of glacial formation, consisting of sand, gravel, boulders, and various clays. Light blasting was sometimes required. The quantity of water required varied between 10,000,000 and 15,000,000 gal. per 24 hr. About 3,000 cu. yd. was removed daily, using a 6-in. nozzle. The excavated material was used for reclaiming a tract of land that was submerged at high tide. Most of the material was carried from the pit to the dump through a flume on a trestle. The minimum slope found desirable was 2.6% The flume was lined with wooden blocks, 10 to 12 in. thick, set with the grain on end. The material was spread on the dump by the use of shear boards and muck rakes. To reach positions of the dump that could not be filled by the use of flumes, penstocks and pipe lines were tried. This latter method has the advantage of possessing greater flexibility of di- rection and lower cost of construction. One vertical penstock, 20 by 30 in. inside and 66 ft. high, was constructed to receive the entire discharge from the flume. It was constructed of 3-in plank, but after three weeks' use the upper 20 ft. was so worn by the discharge from the flume that it had to be lined with wooden blocks. The head used was about two-thirds of the available HYDRAULIC EXCAVATION AND SLUICING 1051 head of 66 ft., and the material could be conveyed through 2,200 ft. of pipe, Another penstock sloping at an angle of 45 gave a head of 20 ft. Heavy material was distributed from this through a pipe line 800 ft. long. Cleaning Sediment from a Reservoir. Engineering and Con- tracting, Apr. 6, 1910, gives the following: Reservoir No. 1 of the Cincinnati, 0., water works had been in constant service for over two years. It was taken out of service on March 20, 1909, and allowed to stand for 4 days in order to allow complete sedimentation before drawing the water. On March 30 the water was drawn off for a depth of 3 ft. during the night and allowed to stand during the day, when the mud was washed off the exposed slopes by hose streams under pressure of flushing pumps in the wier house. The following night the water level was again lowered to stand during the day, when the slopes were washed down. This procedure was repeated every 24 hours until April 9, when the water had become very turbid. The 30-in. drain was then opened, drawing off all the water and such mud as it carried. The deposit of mud remaining on the slopes and bottom was then disintegrated and slid to the drain opening by means of 1^-in. hose streams under heavy pressure. The depth of accumulated mud was found to be from 12 in. to 36 in. and the total amount removed was estinmated .as 30,000 cu. yd. Some 35,494,600 gal. of water were wasted in draining the reser- voir and 16,902,600 gal. were used for removing the mud, or about 505 gal. per cubic yard of mud removed. The cost of cleaning was as follows: Water, at $3.28 per mil. gal $ 55.44 22,032 kw. electric power, at 1.1 ct 242.36 Labor operating pumps 57.94 Labor cleaning reservoir 427.27 Total $783.01 The cost per cubic yard of mud removed was, for cleaning proper, 2.6 ct. Charging in the 35,494,600 gal. of water lost in draining the reservoir 'at $3.28 per million gallons we have an additional item of $116.42, or 0.41 ct. per cu. yd. The cleaning was completed May 1, 1909. Hydraulic Fills on Railway Trestles. Trestle No. 374, Ca- nadian Pacific Ry., in Frazer Canyon, 231 ft. extreme height, was filled in 1896, with 148,000 cu. yd., at a cost of $5,089, or 7.25 ct. per cu. yd., including cost of plant, explosives used on ce- mented gravel, labor, etc. Fifty per cent, was cemented gravel, 30% loose gravel and 20% large boulders, which were removed with a derrick. The plant consisted of 1,450 ft. of sheet steel 15-in. pipe, 1,200 ft. of sluices or flumes, 3 ft. wide x 3 ft. deep; 1052 HANDBOOK OF EARTH EXCAVATION one No. 3 " giant " monitor with 5-in. nozzle, and a large derrick driven by a Pelton water wheel to handle boulders. Piping head was 125 ft. Sluice boxes v/ere laid on a 11% grade for the first 430 ft. and 25% the rest of the distance, 700 ft. The boxes wore partly supported on high trestles. The sluices were paved with wood blocks on the light grades, and old railway rails on the heaviest to protect them from abrasion. The entire force were common laborers, except the pipeman and the foreman, working as follows : One man at " giant," one at head of sluice, two along sluice keeping large stones moving, three at outlet of sluice di- recting stream, and building small retaining barriers of brush or old ties and a foreman who was also a carpenter, total 8. The water used was 20 second-feet or 1,000 miner's inches, the duty performed being 1.77 cu. yd. gravel moved per 24-hr. -inch, which is equivalent to about 980 cu. ft. of water per cu. yd. excavated, but it is claimed that if the head had been about 400 to 500 ft. and the gravel all loose, " the duty of the water would have been increased fourfold." Note, however, that amount of water actually used agrees closely with Mr. Radford's placer mining ex- perience above given. The time of the whole force occupied in making this fill was: Sluicing 95.3 Removing boulders from pit 50.4 Repairing flume and plant 13.5 Total days of 10 hr 159.2 The total number of yards moved divided by the actual work- ing time when sluicing was in progress gave an average of 738 cu. yd. per 10-hr, day. The cement gravel and boulders, it will be seen, greatly delayed work. At Chapman's Creek, in 1894, the railway company made a similar fill of 66,000 cu. yd., at 4.34 ct. per cu. yd. for labor, and estimating 20% of the first cost of the plant as chargeable to this job, the total was 7.15 ct. per cu. yd. The actual labor cost of sluicing was only 1.78 ct. per cu. yd. Mountain Creek trestle was filled in 1897-8 with 400,000 cu. yd. This trestle was 10,086 ft. long, with an extreme height of 154 ft. The fill was carried up on a 1.5 to 1 slope. For the first 60 days, of 10 hr. each, the output of the plant was nearly 1,100 cu. yd. a day, and during that time the cost was: Mattresses $1,370.79 Labor sluicing 1,195.96 Maintenance and repairs 678.90 Superintendence and tools 38505 Total, 65,000 cu. yd. at 5.59 ct $3,630.70 HYDRAULIC EXCAVATION AND SLUICING 1053 About 2.4 ct. per cu. yd. should be added for the proportionate part of the first cost of plant. The water was delivered to the "giant" under a head of 160 ft., the nozzle being 5^ in. The volume was therefore 15.75 sec- ond-feet. The ratio of water to gravel was 19 to 1. The sluice boxes were laid on an 8% grade. The water supply was brought two miles in a flume, 4 ft. wide x 2 ft. high, on a grade of 20 ft. to the mile. The entire plant, including roads, camp, stables, flume, 1,200 ft. of pipe line, 600 ft. of sluice boxes, etc., cost $10,038. Latham Anderson, in a paper published in the 1901 volume of the " Association of Engineering Societies," gives some abstracts from the " United States Geological Survey Report," 1896-97, Part IV, which we can here repeat to advantage in illustrating what has already been done in the way of economic earth ex- cavation. Northern Pacific R. R. Trestles. During 1897, in eight high trestles, 377,000 cu. yd. were moved for about 4.8 ct. per cu. yd. Sluicing and building side levees 3.85 Hay used in levees 0.09 Tools 0.08 Lumber and nails 0.22 Labor building flumes 0.44 Engineering and superintendence 0.11 Total ct. per cu. yd 4.79 In the above work water was carried by gravity. In one case pumping was resorted to, and 42,250 cu. yd. were moved for 13.5 ct. per cu. yd. The plant was inexpensive. One No. 2 " giant " costing $95, with 300 to 1,000 ft. of light sheet-iron pipe costing 27 ct. per foot, and lumber for sluices, which may be re-used in moving from place to place, constituted the outfit. Five to six men were required to erect and operate the plant. This work was done in a dense forest, where the ground to be sluiced had to be cleared. In the one case, above referred to, where pumping was necessary, the cost was: Sluicing and building levees 10.81 Hay used in side levees 0.21 Tools , 0.14 Lumber and nails 0.12 Labor building flume 0.14 Coal used in pumping 1.87 Engineering and superintendence 0.20 Total, ct. per cu. yd 13.50 In all cases the sluice boxes were paved with square 3-in. blocks laid so that the ends would receive the wear due to the gravel. It was found that grades of 7%, preferably 8%, were 1054 HANDBOOK OF EARTH EXCAVATION best where there was large gravel or rock to be moved. The flumes were made in the most temporary manner of 1^4-in. lumber, the boxes being 16 to 18 in. square. Hay was used for building up the side levees of the embankment and easily moved baffleboards to deflect the main current from striking the levees. The waste water was taken off through a waste box. Several gates were provided in the flume so that coarser material might be deposited where the finer is found to be in excess. The following shows the range of costs: Trestle No. Cu. yd. Ct. per cu. yd. 164 18,300 8.21 165 6,200 16.58 167 24,500 * 14.00 170 30,800 8.75 172 4,300 10.55 173 9,700 6.23 , 178 2,100 13.25 179 19,800 9.31 182 53,600 3.80 184 96,650 4.34 185 800 30.24 186 51,600 7.02 189 158,100 5.19 -*! 190 128,800 6.11 191 42,250 13.50 It will be noted how the cost per cu. yd. decreases as the number of cu. yd. to be moved increases. A railway trestle can thus be filled without interfering with traffic, and when filled there is no settlement of the embankment. Photographs of this work, as well as of similar work on the Canadian Pa- cific Railway, are given in Schuyler's excellent book on " Reser- voirs." Further data on filling trestles by sluicing are given in Engi- neering News, Oct. 12, 1899. There is nothing special in the process except the manner of forming the outer dam or levee around the top of the embankment. This is built of alternate layers of tough marsh hay or straw and earth. The hay is shaken down loosely by a man walking along the edge, and the earth is spaded from inside. This hay protects the levee from erosion dur- ing construction, and, as the seeds germinate, a sod is formed. Banks of this character are remarkably solid and show no signs of settlement. One of the great advantages possessed by this^ process is that the tracks are not occupied by work trains. The' only disadvantage connected with the method is the slow speed of construction. A crew of five men and one giant will place be- tween 500 and 1,500 cu. yd. per day. If water is abundant, how- ever, several crews can be worked. E. H. McHenry states that the cost of filling about 30 trestles HYDRAULIC EXCAVATION AND SLUICING 1055 on the Northern Pacific Ry. has averaged for several million yards about G ct per cu. yd., ranging from 1.5 to 25 ct. Cost of Sluicing a Highway Embankment is given in Engi- neering and Contracting, Oct. 9, 11)07, as follows: In connection with the building of a dam in Newaygo county, Mich., a wagon road had to be changed. A cut was to be exca- vated and an embankment made. The cut for the most part was a side hill cut, the grade descending 15% toward the river. The material had to be deposited 40 to 50 ft. below the cut, and from 100 to 500 ft. distant. In all, 20,000 cu. yd. were sluiced; but a record of the cost of only the first 3,000 cu. yd. was kept. For this work there was installed one 3-in. Gould's rotary fire pump. This was set up on the river bank and a 3-in. pipe line run up the bluff. The pump was driven by a 30-hp. motor. One 3-in. hose and a 1^4-in. nozzle were used. The trough for trans- porting the water and earth was of iron, 20 in. wide with 5-in. vertical sides, and was laid on the ground as the wofk progressed upward on the 15% grade. The earth was held to the slopes of the embankment below by means of brush, poles and straw. The nozzle was clamped to a 2 x 10-in. plank, about 12 ft. long, and this plank was pivoted to a standard similar to the jack used by a wagon "wheel painter, only heavier. With this arrangement one man handled each nozzle, and was assigned one helper for moving hose and keeping troughs in shape near the nozzle. The material excavated was sand and gravel. The pump and pipe line were set up in two days by two men. Four men sluiced the 3,000 cu. yd. in four days, or 750 cu. yd. per day. The cost of plant was as follows : 3-in. Gould pump $ 200 500 lin. ft. steel trough 50 ct. per lin. ft 250 3 in. pipe line fittings 250 30-hp. motor 450 Total $1,150 The labor costs were: Setting Up Plant: 2 men 20 hr. at 20 ct. per hr $ 8 Sluicing: 4 men 40 hr. at 20 ct. per hr $32 1 man 40 hr. at 25 ct. per hr 10 Dismantling Plant: 2 men 10 hr. at 20 ct. per hr Total labor $54 The man at 25 ct. an hour ran the motor and attended to the pump. r :.f?.V :\ '' S'.'( Uf> > ?'!' t!'*Vl!l IftMOJSJM -.!i1v TRlN O* (iMU'i n 1056 HANDBOOK OF EARTH EXCAVATION The power to run the motor was furnished by an electric power plant, the charge for the power being 1 ct. per kw. hour, a low price. Summarizing we have the following cost per cu. yd. on this 3,000-yd. job: Installating and dismantling plant 0.4 Labor sluicing 1.4 ' Straw, oil, water, etc 0.1 Electricity at 1 ct. per kw. hr 0.3 Total, ct. per cu. yd. 2.2 Since the first cost of the plant was only $1,150, a charge of $6 a day for plant rental would exceed 100% per annum, even though the plant were idle one-third of the time; but $6 a day is only % ct. per cu. yd. The Sheerboard Method of Retaining Wet Earth. Engineer- ing News, Sept. 5, 1914, gives the following: The sheerboard method of construction is largely used in the building of hydraulic fills and dams. Under most conditions it is a cheaper and more effective way of retaining the water-borne earth than any other method. Under this plan the material is retained by two or more bulkheads or " sheerboards," made of plank laid horizontally on edge and retained by sticks. On light work, two 1 x 12-in. boards nailed to 24-in. stakes about 7 ft. long are sufficient. The stakes should be about 4 ft. apart. After the material is carried up to the top of the first row of sheerboards, a second row is built from 4 to 7 ft. back of the first. The bottom of this top sheerboard is placed from 5 to 10 in. below the top of the lower bulkhead to prevent bulging and flowing out between the bulkheads. The amount of " seal " neces- sary depends upon the nature of the material being handled. In ordinary loams, 6 in. has proven effective, while in fine clay and sandy loam, 10 in. is often necessary. As many sheerboards are built in this manner as are necessary to build up to the desired height. By this method the water is taken off through spillways that lead to pipe drains or natural drainage courses. For full descriptions of this method see the description of the grading of Westover Terraces at the close of this chapter. See also Chapter XV on hydraulic dredging. A Small Sluicing Job. The hydraulic method was adapted in a Southern Michigan village in 1914 for replacing and compact- ing portions of the head-race dike of a gristmill which had been washed out. This head-race winds along a low bluff on one side of a flat valley. Gravelly sand along the top of the bluff was available for the embankment. As it was necessary to install a pump so that this material might be compacted with water, it HYDRAULIC EXCAVATION AND SLUICING 1057 was decided to make the till by the hydraulic method. The fol- lowing data on this work are taken from an article by William G. Fargo in Engineering Xeics-ttecord, Feb. 14, 1918. A 3-in. rotary fire pump was taken from the mill. Five hundred feet of old 21^-in. hose and nozzles were borrowed from the vil- lage fire department. Two sets of troughs were made as shown in Fig. 17, so one could be moved forward without stopping the work. The embankment was first brought approximately to the l<....!.;>| /0'k- 70'- -->k- ed Head Race' ;:.c. 56 >. ....... ..>] CANALS SECTION TIN. ?;< t<- '- ri"' 1 ~7 I j [P*^_[*'**>' s TROUGH DETAILS Fig. 17. Method of Building Small Embankment with Flume. outline A, B, C, D, and water let into the canal so the mill could be started. The spillway in the meantime was inclosed in a coffer-dam. The use of troughs for transporting filling material across the race made it unnecessary to provide a bridge for teams or to defer the turning of water into the canal. The amount of the fill handled by this simple hydraulic equipment was only 670 en. yd., which was placed and sloped in 5i/ days of 10 hr. each. The cost was as follows: Troughs, 156 linear feet or 1,500 ft.b.m. @ $20.00 M, less salvage $ 30.00 1 3-in. pump on hand, no charge. 500 ft. of 2 1 /-in. hose, on hand, no charge. Traction engine, 10 hp., with man, 6 days @ $5 30.00 Labor, 5 men,' 2 days installing and dismantling @ -$2 20.00 Labor, 5 men, sluicing 5% days 55.00 Coal, 2,500 Ib 6.25 Proportion supervision 15.00 Total at 23.3 ct. per cu. yd $156.25 If the work had involved four times as much fill, adding the proportional labor, fuel and engine rental charges, the cost per cu. yd. would have been 16 ct. 1058 HANDBOOK OF EARTH EXCAVATION Sluicing- Earth into a Dam on the Snake River. Three dams of the hydraulic-fill and rock-fill type on the Snake River in Idaho, are described by James U. Schuyler in Transactions, American Society of Civil Engineers, vol. LVIII. The earth fill amounted to 58,000 cu. yd. in one, 62,850 cu. yd. in the second and 48,000 cu. yd. in the third; 114,250 cu. yd. of rock were used in the three dams. A wooden core wall was built of 2-in. plank from the bottom to within 6 ft. of the top, the plank being laid horizontally, breaking joints, and being spiked to 3 x 6-in. uprights placed 2 ft. apart from center to center. The base of this wooden partition was embedded in concrete, which filled the trench to above the line of the bed rock, and formed a tight bond with the rock. The principal part of the hydraulic-filling for the north dam was delivered from the north side of the river through a flume, in the upper end of which a receiving box was placed where the earth was dumped from wagons into a trap. Water pumped from the river washed it down to the dam. The earth was loaded into the wagons by an elevating grader. The water used was about 1 cu. ft. per second, delivered by a No. 4 centrifugal pump. The lower end of the flume discharged along the upper side of the wooden core wall, first filling the voids in the rock-fill and then extending up stream in the water, assuming a very flat slope of 6 or 7 on 1 under the water line. Great difficulty was experienced for some time in stopping a few leaks through the wooden parti- tion, and considerable earth filling was carried through the dam and lost. This may have been due to the settlement of the cribs under the weight of rock, or to imperfect joining with the bed rock. The necessity for doing much of the work in freezing weather was one of the causes of the serious difficulty encoun- tered in making the hydraulic fill. Layers of frozen earth were formed in the embankment and these subsequently thawed out when the water was allowed to rise against the dam, treating alarming settlement in the earth next to the rock-fill. This alarm was due to the extent of the disappearance of the earth- fill below the water line along almost the entire length of the dam, and the volume of leakage through the dam when the water reached its normal height. This leakage was not definitely meas- ured, but it was estimated at one time at more than 6 cu. ft. per second. In an ordinary earth dam such leakage would necessarily be fatal. In this case it was never a source of actual danger, and only resulted in the loss of 2,000 to 3,000 cu. yd. of earth fill- ing (possibly less), before the leaks were finally closed with fine gravel brought in a barge from a few miles above. The contract prices for these dams were: Dry earth in em- HYDRAULIC EXCAVATION AND SLUICING 1050 .bankment, 27.5 ct. per cu. yd.; and sluicing earth, 37.5 ct. per cu. yd. These prices were high for several reasons, namely the high cost of fuel, the scarcity of earth in the neighborhood of the dams and the high price of labor. Dam at Tyler, Texas. This earth dam was built in 1894 by the hydraulic method. The embankment is 32 ft. high, 575 ft. long, and contains 24,0050-ft. head. The water from the smaller pump is delivered with a 7o-lb. head and is used to cut the banks. Water from the second unit is delivered at the pit without head and simply gives a volume sufficient to carry the material to the dam. By dividing the pumping head in this way a considerable saving was effected in the power cost. Handling of Jets. The jets are directed against the toe of the borrowpit bank, which is undermined, causing it to cave in. This results in the spoil being broken up and allows the water to carry it away. The soil -laden water flows to the lowest point in the pit, passing through a grizzly or screening device made of vertical 2-in. pipe set 4 in. apart. Rocks more than 4 in. in diameter are screened out and passed through a crusher set just below the grizzly. From this point the material is pumped by a 12-in. mud pump driven by a 300-hp. motor through a 14-in. slip-joint steel pipe to the toe of the dam. The pipes discharge their contents on the outer edges of the toes. The flow is directed toward the center of the dam by the work of one man, who by the use of boards^ so controls the dis- charge from the pipe line as to build up small dikes along the edge of the toes. The coarser fill remains near the point of discharge, the remaining burden of the water being deposited au- tomatically as the velocity of the stream decreases, until the pond is reached. Here the fine clay is settled in comparatively still water. The point of discharge is changed along the toes by the removal of successive pipe lengths, to maintain uniform rela- tion between the widths of the dry banks and pond. Pipes are removed from the end of the discharge line without interruption to the pumps, so that a delivery run across the toe is always begun from the end furthest from the pit. Operation of Mud Pumps. The mud pumps will operate against a head of 80 ft. When the head exceeds 80 ft. a booster of equal capacity is cut into the line. The head on the mud pumps depends largely on the character of the soil. With an excess of clay the friction is comparatively low, and the power required is a minimum. An example of this fact may be had with the present arrangement at Calaveras. In order to reduce interruptions to a minimum, duplicate units have been installed, so that should work be discontinued for any reason the crew can be immediately moved to another location. Two pits at the same elevation and the same distance from the dam are used alternately. One of these pits is composed of about 65% clay and 35% shale rock. In the other these percentages are re- 1072 HANDBOOK OF EARTH EXCAVATION versed. When using the first pit one pump is sufficient. If the second pit is used, a booster has to be cut in and the power is doubled. Wear of Pipes. One of the problems encountered, in the work was to reduce the wear on pumps and pipes. The velocity of the water and the character of material which it carries are the fac- tors that affect the life of the carriers. Although a high velocity is desirable to secure the maximum carrying power of the water, it was found that the minimum velocity in the pipe lines which would keep the material in suspension caused the least wear on the pipes, and although the output was decreased the resulting unit cost was lower. With the installation described this critical velocity was 12 ft. per second. On an average the water carries 8% of its volume of material. All the wear takes place on the bottom third of the pipe cir- cumference. This feature is so pronounced that the coating on the interior^ of the line is not disturbed on the top two-thirds of the circumference even when the plate at the bottom is worn through. High-carbon steel pipes are now being tried, and the result has justified the slight increase in initial cost. The pipes are turned twice during their life, allowing full use to be made of the metal. / Wear of Pump. The runners or impellers in the pumps are subject to excessive wear. A worn-out runner means an idle crew for half a shift while it is being replaced. Three kinds of ma- terial have been used cast iron, cast steel and manganese steel. Manganese-steel runners cost about six times as much as cast iron; but the cost per cubic yard was cut almost in two by the use of the former. In some cases it was found that the man- ganese-steel runners wore unevenly, becoming unbalanced and creating excessive vibration of the pump. The yardage handled through the life of a runner varies with the character of the material pumped. It has varied from 30,000 with sand and gravel to 200,000 with excessive clay and soft shale rock. Removal of Water from Pond. During the first year of sluic- ing the excess water in the pond was allowed to flow out through a vertical pipe in the center leading to the culvert. To give this pipe stability a double line was used, consisting of a 16-in. pipe set inside of an 18-in. pipe, the space between the two being tilled with cement grout. It was found that as the length of this pipe increased it was susceptible to the movement of the clay core, and this scheme was abandoned and the pipe filled with concrete. Two trenches 4 ft. wide were cut through opposite ends of the upstream toe and bottomless flumes constructed of lin. boards HYDRAULIC EXCAVATION AND SLUICING 1073 1074 HANDBOOK OF EARTH EXCAVATION with 4 x 0-in. posts and 2 x 4-in. spreaders. Excess water from the pond is allowed to flow out through the box which is farthest from the point where the pipes are discharging, and runs down the slope of the dam, which is riprapped up to the outlet to pre- vent erosion of the slope. To raise the level of the pond, rock and gravel are dropped into the cut to the required height for the width of the dry toe. The amount of clay contained in the discharge from the pond varies from 0.1 to 2%. This depends on the relative amounts of material delivered, clay sometimes be- ing wasted in order to maintain the proper relation between the dry toes and the clay core, to insure the stability of the struc- ture. Monthly tests are made of the clay core by taking samples of the fill at 10-ft. intervals. A 1^-in. pipe with a wooden plug in the lower end is forced down to the point a,t which the sample is to be taken. The plug is tapped out by means of a rod put down inside of the pipe, and the plastic clay presses into the end. It is impossible for four men to force the pipe any deeper than 60 ft. At a depth of 60 ft. below the pond surface a practically constant relation of 75% of clay and 25% of water by weight is found. In addition to this quantitative test a traverse of the pond between the upper and the lower toe is also made, in order to ascertain the relative compactness of the fill. This traverse is made by forcing a pipe as far down as possible into the fill at 50-ft. intervals. The comparison between the periodical depths and distances from the edge of the pond is indicative of the consolidation of the mass. Labor and Cost Conditions. Comparatively few men are em- ployed on the sluicing units. Two units are working two shifts each and the total number of men per unit per shift is fifteen, making sixty altogether. When it is considered that an average of 3,600 cu. yd. of material por day is transported a distance of 3,000 ft. with a crew of this size, the advantage of this method of excavating and placing fills is evident. With the single ex- ception of the relative quantity and quality of the fill, nothing is left to the judgment of the engineer. The cost of excavating and placing this by the hydraulic method depends as much on the character of the material as on the cost of labor, material and power. The relative coarseness of the material affects the head upon the pumps. The direct cost of sluicing the first million cubic yards of fill was about 25 ct. per cu. yd. This is the bare cost of the work and includes only the expense of pipes, pumps, motors, belts, power and labor .used directly on the sluicing work. No interest, overhead, super- HYDRAULIC EXCAVATION AND SLUICING 1075 intendence, insurance or the prorated auxiliary costs of clearing the reservoir site, building and maintaining roads, trails, camp, etc., are included in this figure. In this connection it must be borne in mind that the work accomplished so far has been on the base of the dam, and that as the height is increased the unit cost of placing the sluiced fill will also increase. The work is being carried on by G. A. Elliot, engineer of the Spring Valley Water Company. Sliding of the Dam. Before this dam was finished, a large part of it slid out, as described in Chapter XX. Percentage of Solids Carried on Calaveras Dam. According to Engineering Xeics, Oct. 1, 1914, the material for the construc- tion of Calaveras Dam, California, consisted of 20 to 50% of clay, and the remainder of gravel and sand. This was sluiced from a borrow pit, and down an open channel, having grades varying from 5% to 7%, to an 8 x 8-ft. concrete-lined sump. In the open channel near the sump, was a screen by which all boulders larger than 5 in. in diameter were removed. The con- sistency of the mixture arriving at the sump was usually about 20% solids and 80% water. At the sump this was automatically diluted when necessary, an average of about 15% material in suspension being carried to the dam. Hydraulic Grading of Westover Terraces, Portland, Ore. R. M. Overstreet, in Engineering Record, Sept. 12, 1914, gives the following : The work consisted in cutting down a steep hill and grading it into roads and terraces by means of hydraulic giants, sluices and sheer boards. A large part of the earth was carried half a mile in a flume and used for filling low ground. The total yard- age was approximately 3,000,000. Plant. The installation of pumping machinery at that time consisted of four 10-in. five-stage Worthington centrifugal pumps direct connected, in units of two each, to two 650-hp. two-phase, 60-cycle, 2,000-volt Westinghouse motors with a 25% continuous overload capacity. The guaranteed efficiency of the motors was 90% and of the pumps 70%, making a combined plant efficiency of 63%. The pumps were designed to deliver 8,400 gal. per min. under 375-ft. head at 690 r.p.m. As the excavation progressed the pumping head continually increased so that it was necessary to install (Oct., 1910) ad- ditional pumps as follows: One 16-in. Worthington turbine pump, direct-connected to a 900-hp. Westinghouse two-phase in- duction motor. The efficiency guaranteed on the motor under full-load condition was 91%. The pump was designed to deliver 8,400 gal. per min. under a pumping head of 675 ft. with a head 1076 HANDBOOK OF EARTH EXCAVATION on the suction of 375 ft. from the five-stage pumps, leaving a resultant head of 300 ft., and the efficiency guarantee was 71%, making 64.6% the efficiency of the combination. After a shutdown of 14 months from Sept., 1912, to Nov., 1913, the pumping plant was entirely rearranged. One group of two 10-in. pumps with motors had been taken to another piece of work after the shutdown, which left but two 10-in. pumps at elevation 25, while the 16-in. pump was taken to a point on the hill west of the improvement and set at elevation 326 to act as a booster in the line. The discharge from the lower pumps was through two lines of 18-in. wood-stave pipe for 1,500 ft., and && Fig. 21. Section of Flume. from here in a 24-in. pipe to the booster. From the booster there were two 18-in. lines, 400 ft., converging into a 24-in. line, 300 ft. long, leading to a plug. From this point the 14-in. supply lines were taken off to the giants. Two giants were con- nected up, but only one was used at a time. A record of the elevation and location of the giants was kept and the pressure taken on each giant once every 8-hr, shift, and the discharge computed from these pressures. The working pressure at the nozzle varied from 50 to 80 lb., according to the elevation of the giant and size of the tip. In 1914 the plant remained the same, there being a connected load of 1,550 hp. which delivered about 5,850,000 gal. x)f water per 24 hr. against a total head of 745 ft. with an efficiency of HYDRAULIC EXCAVATION AND SLUICING 1077 about 49.3%. This low efficiency was due to the throttling of the booster pump which was operating under conditions far dif- ferent than those for which it was designed. Trestle and Flume. The earth was carried to the dump in the lake in a 0% grade flume supported on top of a timber trestle crossing streets and private property and having a maximum height of 75 ft. and a total length of 2,500 ft. See Fig. 21. A temporary flume on a 9% grade was bracketed to the side of the trestle and used for making a fill of about 300,000 cu. yd. about half way between the cut and the lake tract. The water lines from the pump house to the giants were also hung on this trestle. , The (>%. flume was divided into two channels by a bulkhead. One side of this was lined with 4 x 4 x 8-in. blocks laid with the grain up and the other side with %-in. white iron plates, 21 x 34 in. in dimension and weighing about 140 Ib. each. The cost of construction of the trestle and flume, not includ- ing the lining, was $24.20 per 1,000 ft. b. m., of which $9.08 was' for labor, $2.12 for iron and nails, and $13 per 1,000 ft. b. m. for lumber. This is equivalent to $6.75 per lin. ft. Iron plates cost from 1% to 2}4 ct. per Ib. Life of Iron Plates and Wood Blocks. The life of the iron plates was very Satisfactory as compared to the wood blocks. The average life of the wood blocks on a 6% grade, working in gravel, was found to be 125,000 to 150,000 cu. yd., while with the plates it was possible to carry 1,000,000 to 1,200,000 cu. y.l. \Yith the block lining it was found necessary to replace blocks about every live weeks, which woulJ have occasioned consider able loss of time ha 1 it not been for the extra flume. It was found that the gravel running over the steel plates made so much noke that res'dents in the vicinity complained of being unable to sleep at night, so the steel-lined flume was used during day- light hours and the wood-lined side at night. Life of wood blocks in clay was found to be about 1,000,000 cu. yd. Tunnel. At one point a flume >vas carried through the hill in a tunnel 5i by (> ft. in section. This tunnel was constructed on a 10% grade through hard gravel. It was about 530 ft. long and cost $2.5)5 per lin. ft. This tunnel was extended up through the property from the original portal by constructing a covered box and filling over it. In Sept., 1912, the 6% flume was torn down and all remaining material sluiced through the tunnel. Sluicing. When running in gravel the discharge end of the flumes had to be cleared away every few days, as the gravel would pile up and not spread, so that it was necessary to level off the gravel fill with a steam shovel and cars. When running 1078 HANDBOOK OF EARTH EXCAVATION in clay the material would flow 800 to 1,000 ft., making a fill as level as a table. Blasting Clay. When the giants were working in gravel the bank was undermined by pressure from a jet without the use of powder. In clay the pressure of the stream had little effect on the bank and it was necessary to blast the material. A powder crew, consisting of 8 men, was employed on the day shift to keep the clay broken up in front of the giant. By al- Fig. 22. Arrangement of Sheerboards for Slopes Made by Hydraulic Sluicing. ternating giants from one shift to another it was possible to keep the clay well broken up for a full day's run. A stumping powder of 20% strength was used in charges of from three to seven sticks, and from 400 to 700 Ib. were used daily. Powder cost $176 per ton delivered on the work; fuse, $4.50 per 1,000 ft.; and caps, $9.80 per thousand. Terraces Built with Sheerboards. The hill attacked in this work was graded into a series of terraces and streets, sheer- boards being used to hold the material to the desired slope. See Fig. 22. These were made up of two 1 x 12-in. pieces nailed HYDRAULIC EXCAVATION AND SLUICING 1070 one above the other to 2 x 4 -in. stakes, or 7 ft. long, spaced about 4 ft. center to center, and driven into the ground in the embankment. The first row of sheerboards is placed at the line of intersection of the slope with the ground; the second, third and subsequent rows of' sheerboards are placed as the em- bankment rises, each line being spaced according to the de- signed slope. Slopes on this work were 1% to 1. The bottom of each sheerboard is placed from 2 to 10 in. below the top of the upper board in the preceding bulkhead, depending on the nature of the material of which the embankment is being made. In gravel, for instance, the seal is less than is required for making a fill of fine clay. In the lighter and finer soils it is % necessary to brace between the stakes as shown. After de- positing its load the water is taken off the fill through spillways, which are located at convenient points. These consist merely of flumes running down the slope through the sheerboards. By this method the mass of the embankment is continually drained as the fill is deposited, and when the fill is completed it is as compact and substantial as though it were in the original bank. The amount of lumber required for the sheerboards can be ob- tained from the following data : Depth of seal, in. Feet, board measure 2 1.09 x area of vertical projection of slope 1.20 x area of vertical projection of slope 6 1.33 x area of vertical projection of slope 1.50 x area of vertical projection of slope 10 1.71 x area of vertical projection of slope - 12 2.00 x area of vertical projection of slope Stakes and bracing 1.50 x area of vertical projection of slope Add 10% for loss due to lap, waste, etc., on 1 x 12-in. lumber. When pumping against a head of 420 ft. during July, 1910, with 1,300 hp. connected, the yardage moved was 37,800 cu. yd., requiring 130,000,000 gal., the earth carried being 5.78% of the volume of water in flumes of 6% grade. The cost of pumping per million gallons of water was: Electric current at 0.6 ct. per kw.-hr $24.38 Pump, operators, $270 for the month 2.08 Supplies, repairs, etc 0.48 Total per million gallons $26.94 , i>I bi'.CM .*jj . -Ttiil I ' . ''.'Vr'Mj fri.:Ti' 7 on --/;'// {{ji't >({} t-''rfi There were 245 gal. pumped per kw. hr. The pumps worked 539 hr. during July. In February, 1914, the average pumping head was 707 ft., and 101,790,000 gal. were pumped, moving 94,091 cu. yd. the ratio of earth to water being 18.6%, which was the highest percentage attained ; the grade of the flumes being 10%. The cost of pumping per million gallons was: 1080 HANDBOOK OF EARTH EXCAVATION Power at 0.6 ct. per kw.-hr $29.68 Pump operators, including booster pumps, $515 5.05 Supplies, repairs, etc 0.57 Total per million gallons $35.30 The connected horsepower was 1,550, and 434 Ifr. were run during the month. The material was clay. The work was car- ried on for 34 months at an average rate of 75,000 cu. yd. per mo., and the article above quoted contains a table giving out- put and pumping cost data for each month of the entire period. The price of electric power was very low (0.6 ct. per kw. hr.), and about 9.3 kw. hr. were used per cu. yd. of earth, the earth being mostly clay, and the average pumping head about 600 ft. Each cubic yard of earth required an average of 2,100 gal. Hence the power for pumping (at 0.6 ct. per kw. hr.) cost about 5.6 ct. per cu. yd., or $27 per million gallons. About 226 gal. were pumped per kw. hr. A typical distribution of the pumping heads was as follows, on Apr. 16, 1914: Loss of head in pumps 18.4 Loss in pipe lines to booster pump 12,0 Loss in booster pump 34.5 Loss in pipe line to giant 30.2 Effective head at nozzle 109.2 Lift to nozzle 556.6 Total pumping head, ft 770.9 Disposal of Earth by Means of a Chute. Engineering and Contracting, Oct. 13, 1909, gives the following: In the construction of the new engine house at the Lake View pumping station at Chicago, 111., the, contractors used an eco- nomical and efficient method of disposing of tlie sand and gravel encountered in the excavation for the foundations of the build- ing. The building is located about 300 ft. from the shore of Lake Michigan and the sand and gravel were conveyed by a chute to the water's edge of the lake, where the waves disposed of it after each storm. A pump installed for taking care of seep- age water was used to wash the sand and gravel through the chute. Some trouble was first experienced, owing to the fact that the fall was not great enough. It was found that to handle the sand by this method it was necessary to have a grade of about 5%. One or two men were placed along the chute to prevent accumulations of sand, for if it started to collect, it would accumulate very rapidly and cause a blockade. When it was found that the chute would be a success, a screen of 1,4 in. mesh was placed in a section at the bottom of the HYDRAULIC EXCAVATION AND SLUICING 1081 chute for a distance of about 8 ft. in length. The sand going through the screen was allowed to fall into another portion of the chute at a lower level, the gravel accumulating on the screen being removed by one laborer with a hose. In order to remove the large gravel and cobble stones the gravel was al- lowed to fall over another screen of 1%-in. mesh. Between 50 and 60 cu. yd. of the best quality of gravel for concrete was obtained in this way each day at the cost of four laborers' wages. After the gravel screen had been in successful operation, another screen was placed in the chute lower down; this screen had 10 meshes to the inch. From this screen about 20 cu. yd. Fig. 23. Wood Blocks and Retaining Ribs Before Use. of the best quality of torpedo sand and gravel was obtained each day, at the cost of one laborer's wage. In all there was ob- tained about 2,000 cu. yd. of torpedo sand and gravel suitable for concrete. About 12,000 cu. yd. of sand and gravel were han- dled by means of the chute. The Denny Hill Regrade, Seattle. This project, comprising an area of 43 city blocks, was undertaken at Seattle, Wash., as described at length in Engineering \'eus, Mar. 31, 1910; 5,400,- 000 cu. yd. of material were moved from a section in the heart of the city by the hydraulic method. The maximum length of cut was about 3,000 ft. and the maximum depth 1 10 ft. The contract price was 27 ct. per cu. yd. The material was dis- charged into (Jeep water in the harbor. In order to avoid dis- I y 1082 HANDBOOK OF EARTH EXCAVATION turbing street traffic it was carried part of the way through a tunnel under the street. Besides the hydraulic jets, which were steadily eating into the breasts of the various cuts, a construction railway had been con- stantly in operation, hauling dirt from the steam-shovels and dumping it into an open cut. Two trains, consisting of four side- dump cars each, were operated on this single-track road, with a third locomotive to help out on the steeper grades. In order to break up the dirt from these trains and wash it into the tunnel, two small-size giants were installed at this point. Fig. 24. Effect of Wear on Blocks. These were supplied by a 2-in. and a 4-in. iron pipe, respectively. One feature of the work which was favorable to its early com- pletion was the small percentage of rock occurring in the mass to be removed. And although the greater part of the mass was a very hard, blue-black clay so hard and closely-compacted, in fact, that in the earlier attempts it was seriously doubted that it could be handled hydraulically at all still the hardest part of the work is now past. And at this time, the close of ,1909, the entire project is more than three-fourths completed. Sluiceway Linings. An interesting point in connection with all hydraulic grading is the extreme difficulty encountered of find- ing any substance which will resist the high attrition in tho sluiceways. The remedy finally hit upon was removable wood blocks, placed end up. Where these are used in wood-stave pipe. HYDRAULIC EXCAVATION AND SLUICING 1083 two of the side-sections of same are cut larger to act as retaining ribs ( see Figs. 23 and 24 ) and the blocks are turned in a lathe so as to give a maximum length of block at the bottom of the pipe, or point of greatest wear. So important is this point, that the use of wood-block lining has been patented by a local firm, and one successful damage-suit has already been brought against infringers. Where the wood-block lining is used in flumes, tunnels, etc., oblong blocks, 6 in. long, are cut from 6 x 12-in. rough lumber, and the bottom of the sluiceway is lined with these, laid end up to wear. Evidently, when these wear out, it is a simple matter to remove them and replace with new blocks. In order to hasten the sluicing, both by the loosening of large masses and by the breaking up of the more closely-compacted lumps of the shale-like clay, blasting powder is used through- out the area under regrade. Comparatively small charges are used, however, and very little disturbance has so far resulted from this cause. Sluicing Silt to Reduce Canal Leakage. The following is from an article by Fred J. Barnes in Engineering News-Record, May 17, 1917. Leakage from the main canal of the Grand Valley irrigation project in Colorado became excessive and an attempt was made to stop it by sluicing clay, in the hope that the clay would settle into the porous material in which the canal was built and stop the leakage. At one point there was a small bed of about 8,000 cu. yd. of clay. This material was very dense and compact, in its natural state requiring a pick to loosen it. It contained 16% moisture and very little sand. The sieve test indicated 100% passing a No. 50 screen, 99.85% passing a No. 100 screen, and 98.22% pass- ing a No. 200 screen. The bed was on the upper side of the canal immediately adjacent to and above the water surface of the canal. A two-stage centrifugal pump with 8-in. suction and 6-in. dis- charge was direct connected to a 75-hp., 890 r.p.m. induction mo- tor mounted on the pump base. A suction sump was built in the canal, and the motor and pump were installed in a small shed adjacent. The discharge line consisted of 40 ft. of 8-in. spiral- riveted iron pipe and 75 ft. of heavy 6-in. canvas hose connected by a flange union to the giant. The latter was mounted on a heavy frame to hold it in position and had counter-weights to facilitate handling the nozzle. The giant proper was about ft. long, tapering in inside diameter from 7 in. to 3} in. An ad- ditional nozzle of 3-in. inside diameter was also provided. A cut was made through the upper bank of the canal to drain the effluent from the clay pit into the canal. A 2-ft. metal Ap- 1084 HANDBOOK OF EARTH EXCAVATION poletti weir was installed in the cut. A wooden flume extended from the weir across the canal, clearing the water surface by 6 in. Notches of varying depths were sawed in the vertical sides of the flume at 2-ft. intervals to distribute the muddy water evenly over the channel flow. The pump discharge was found to be 3.1 cu. ft. per sec. With the 3-in. nozzle this gave 63.8 ft. per sec. issuing velocity. By elevating the giant the stream could be thrown about 150 ft. hor- izontally. With the 3i^-in. nozzle the issuing velocity was 46.7 ft. per sec., and the extreme horizontal range was about 110 ft. One man attended to the motor, pump, pipe line and distributing flume, while a second man handled the giant. The idea was to utilize the maximum force of the stream in breaking down the clay to small particles and getting it thor- oughly mixed with the water. It was found most advantageous first to dig a deep hole in one side of the clay bank by holding the giant pointed downward on a small area for 15 min. or so. The sides of the clay bank were then trimmed to a vertical face, and the giant stream was played over this face. It appeared best to keep the stream moving continually over the face of the de- posit, so as to remove the material in thin layers rather than to undercut large masses and have them fall into the sunip. The clay required considerable agitation before becoming thor- oughly mixed. The crest of the weir in the cut from the sump to the dis- tributing flume was about 2 ft. above the bottom of the sump, so that this served as a settling basin for larger lumps. The sump floor was kept at this elevation by occasionally turning the giant stream downward and keeping it pointed on one place for a short period. After the clay became thoroughly satu- rated, it mixed with the water readily and remained in suspension for about 60 min. in still water, although some precipitation began immediately. The effluent passed the weir with a vertical fall of 2 ft. and was carried out in the wooden flume with a velocity of about 5 ft. per sec. over wooden riffles on the bottom, which tended to grind up still more any pieces of clay that had been swept along. Samples of effluent were taken at. 2-hour intervals to determine the percentage of clay carried in suspension. These samples varied widely, showing from 4 to 5% of clay by weight; the average clay content, as indicated by samples, was 5.4%. The total running time was 83i hr., during which period 941,000 cu. ft. of water left the giant. The total amount of clay moved out, determined from cross-sections of the bank before and after HYDRAULIC EXCAVATION AND SLUICING 1085 sluicing, was 2,749 cu. yd. This indicates 7.88%, by volume, of clay in the water. The effluent after entering the canal passed through different types of section where, on account of the rapid succession of abrupt changes in velocities, the rapidity with which the silt dropped could not be accurately found. It was observed that there was little tendency toward separation when the velocity ex- ceeded 1 ft. per sec. ; but when the mean velocity dropped ab- ruptly from 1 ft. per sec., or more, to 0.4 or 0.5, there was im- mediate precipitation. Only slight quantities of silt were car- ried as far as Lewis siphon ; the bulk dropped out in the first 2 miles below the tunnel. The largest observed percentage by weight of silt in the canal water immediately below the silting plant (and due entirely to the plant operation) was 0.48%. At Lewis siphon the largest observed content was 0.002%, indicating practically complete precipitation in 8.8 miles neglecting the 1.4 miles of tunnel where precipitation was impossible. The obvious conclusion is that for best distribution the velocity of the current in the canal should exceed 1 ft. per sec., except where it is desired to deposit the silt. The pressure head was found by gage, but no vacuum gage was available, so that the suction head had to be computed. The total head thus found was 135.2 ft., using a 31^-in. nozzle. The theoretical horsepower required was 48.3 ; the actual power consumed was 60 kw. at the Cameo power station, giving a com- bined efficiency for the transmission line, motor and pump of 60%. Using a 3-in. nozzle, the total head worked against was 160.7 ft. This required 57.3 hp. theoretically, and the actual consumption was 72.3 kw., making the combined efficiency then 59.2%. When working the stream against a vertical face of the bank from a distance of 40 ft. or less, the 3i^-in. stream seemed as ef- fective as the 3-in., with much less power consumption. At greater distances or when digging was required, the 3-in. stream worked faster. The, installation cost of the silting plant was largely in re- pairs to the pump (an old one in poor condition) and labor of erecting the pump, motor house, pipe line, distribution flume, etc. All material was old stuff lying around the camp. The transmission line was already built. No depreciation charge was allowed on machinery, since much overhauling was neces- sary and the pump was in better condition after sluicing ended. The cost of power was comparatively high, 3.47 ct. per kw. hr. in September and 3.84 ct. in October (because of the small power 1086 HANDBOOK OF EARTH EXCAVATION output for these two months at the station and the relatively high influence of fixed charges ) . The following was the cost : Plant erection, labor $0.066 Plant erection, materials .001 Plant operation, labor 039 Plant operation, materials 001 Plant demolition, labor 037 Power 068 Engineering 056 Closing entries (automobile expense, etc.) 023 Total per cu. yd $0.291 Total clay moved, cu. yd 2,749.0 Total power used, kw.-hr 5,290.0 Power used, kw.-hr. per cu. yd. of clay 1.92 Hours of plant operation 83.5 Water pumped, sec. -ft 3.129 Clay in suspension, % 7.88 Total head on pump using S^-in. nozzle, ft 135.2 Total head on pump using 3-in. nozzle, ft 160.7 Approximate combined efficiency of transmission line, motor and pump, % 60.0 One item of $145.66 for giant, pipe and fittings, all of which were in as good condition after work was completed as when received, is not included in the above cost. Bibliography. " A Practical Treatise on Hydraulic Mining in California," Aug. J. Bowie ; " Manual of Hydraulic Mining," T. F. VanWagener ; " Hydraulic and Placer Mining," Third Edi- tion, Eugene B. Wilson ; " Reservoirs for Irrigation, Water Power and Domestic Water Supply," James D. Schuyler. " Hydraulic Excavation," Latham Anderson, Jour. Asso. Eng. Soc., Vol. 26, Jan., 1901. " Notes on Hydraulic Sluicing," Eng. and Min. Jour., April 8, 1911; "Making a Fill by Sluicing Through a Flume," Eng. News, Jan. 22, 1914. *""P" '' Ju; TK*in.*,-|> CHAPTER XIX ROAD AND RAILROAD EMBANKMENTS Although much of the information in preceding chapters is applicable to the building of embankments for roads and rail- roads, it is desirable to have a special chapter for this branch of earthwork. Embankments for roads and railroads differ from other em- bankments, except levees, in that they are usually quite long. They differ from earth dams and levees in that they need not be watertight. Road embankments are usually not so high as railroad " fills," and most of the earth is commonly secured from the ditches. The shallowness of the fills makes road work more expensive than railway work. Also the area of trimming of earth sur- faces is proportionately greater for roads than for railroads, and makes the cost per cubic yard higher. Finally, it is usu- ally specified that highway fills and subgrades must be sprinkled and rolled, whereas railway fills are seldom rolled or even watered to effect consolidation. Contractors experienced in railway earthwork usually under- estimate the cost of highway work, for the reasons just given. But study of the data in Chapter VI will prevent such under- estimates. It should also be remembered that the hard earth crust of an old road is often as difficult to loosen as hardpan, and that when loosened it is not as easily shoveled or scraped as ordi- nary field earth. In designing railway earthwork, the engineer usually aims to " balance the cuts and fills," that is the earth yardage of the excavated parts of the railway line is made approximately equal to the yardage of the embankments. This frequently results in long hauls for the earth. Where the yardage is small and the hauls become very long, it is usually cheaper to secure the earth from " borrow pits " near the fills. The increasing use of dragline excavators will probably result in more frequent " borrowing " of earth for fills and " wasting " of earth from cuts, as described later in this chapter. The shrinkage of earth embankments is, discussed in Chap- ter I. Besides shrinking, embankments are apt to settle into the material on which they are built, making it difficult to dis- tinguish between settlement and shrinkage. A striking illus- tration of the settlement of an embankment is shown in Fig. 1, a diagram of what happened to a fill across the Papio Valley for the Union Pacific Ry. 1087 1088 HANDBOOK OF EARTH EXCAVATION A Method of Determining Subsidence and Shrinkage has been worked out for use on levees in the Orleans Levee District in Louisiana, and is described in Engineering and Contracting, Oct. 18, 1916. Briefly, a 2-in. pipe is driven until sufficient pen- etration is secured through good solid "earth, so that the pipe cannot be disturbed by the superimposed weight. A 3-in. pipe screwed into an 8-in. flange, which in turn is bolted onto boards, is slipped over the 2-in. pipe. The boards give sufficient bear- . - Bumbo Soil ftl *.'. Water Bearing Sandu Gravel '' . ' ; .. ' ' ' .' \ :-':. * . y^ Fig. 1. Section Through 95-Ft. Fill Showing Subsoil Strata Before and After Settlement. ing surface so that the 3-in. pipe sinks with the original ground. Its upper end is closed with a cap. Levels taken on this cap show the subsidence, and taken in connection with levels on top of the embankment they show the shrinkage. Calculating the Ultimate Subsidence of an Embankment. In the Transactions of the Association of Engineering Societies, July, 1892, there is a paper by Henry M. Carter of the Boston Society of Civil Engineers, on the settlement of the embank- ROAD AND RAILROAD EMBANKMENTS 1089 ment between Squantum and Moon Island, Boston Main Drain- age Works. The embankment is 4,200 ft. long built on soft ma- terial. The embankment was to be 20 ft. wide on top and to have side slopes of 2 to 1. The original surface on which the embankment was to be built consisted of a gravel bar at about half tide elevation, varying in thickness from 2 to 8 ft., and extending from Moon Is- land 2,800 ft., toward Squantum. At this point the bar disap- peared and the surface showed mud alone at the elevation of low water. Two sets of borings showed an apparently solid gravel bar, so a contract was let for building an embankment on this bar and for dredging out the mud for the remaining distance and filling in with solid earth. After work was commenced a doubt was raised as to the extent of the gravel bar, and further bor- ings showed it to be entirely underlain by mud. This discovery caused the abandonment of the original plans. It was decided to build the embankment to 2 ft. above the proposed grade and to allow it to settle thoroughly 'before attempting further work. A very careful set of borings was then made to determine the depth of mud along the whole line of embankment. Iron plates 2 ft. square, attached to rods, were set in the fill already built, so that records could be kept as these settled with the em- bankment. Observations have been made on the settlement of this em- bankment for a period of 9 years. One rod settled 14 ft. during the first six months, 2 ft. during the next year, the embankment being built as the sinking took place. The entire settlement to date was 17.4 ft., the gravel filling having sunk through the mud until it rested on the hard clay beneath. The settlement from 1885 on was plotted as a curve, and from these curves the ultimate settlement at each point was figured, as also the date when it would become less than 0.01 ft. per year. These calculations were used in setting the invert grade of the sewer. Rods were placed on top of the sewer with the inten- tion of further study comparing the actual settlement with the calculated settlement. A remarkable feature in the settlement of this embankment is that, while at points the fill has sunk through the mud until it is supported on the clay beneath, at other points it is still supported upon the mud. A fourth set of core borings show the condition existing when the embankment had settled to ap- proximately its permanent position. A profile published with this paper gives a good idea of the degree to which the mud has been compressed. 1090 HANDBOOK OF EARTH EXCAVATION A Tamping Roller. Engineering and Contracting, Dec. 4, 1907, gives the following: The face of each roller is studded with numerous " iron feet " which do the tamping. See Fig. 2. In road or street work, the subgrade to be compacted is first loosened with a plow to a depth of about 6 in. When the rolling tamper is drawn over this loosened earth, its iron feet sink into it nearly to their full length, and thus begin the process of compacting the earth at the bottom. Successive trips of the roller over the earth result finally in a mass so thoroughly compacted that the " iron feet " no longer sink into it, but ride on top. To test out the roller, a clay soil, weighing 90 Ib. per cu. ft. Fig. 2. Traction Engine Drawing Tamping Rollers. in its natural state in place, was plowed up and rolled with rolling tampers until their " feet " walked on top of the com- pacted surface. Then a cubical block of this soil 2 ft. square and 6 in. thick was dug up and weighed; Its weight was found to be 115 Ib. per cu. ft., as compared with 90 Ib. before rolling. By mixing some gravel- with the plowed clay, and rolling, a weight of 125 Ib. per cu. ft. was easily secured. The tamping roller is made by W. A. Gillette, South Pasadena, Calif. Cost of Grading Southern Roads. The cost of grading a num- ber of gravel and sand-clay roads in several of the Southern States during 1910, under the supervision of the U. S. Office of Public Roads, is given in a text book on Highway Engineering, by Messrs. A. H. Blanchard and H. P. Browne. The costs were as follows: Labor Team Cu. yd. Cost per Haul 10-hr. 10-hr, moved cu. yd. in ft. Tools used day day 2,400 15 200 , _ $15Q $2QO ROAD AND RAILROAD EMBANKMENTS 1091 Sandy 3,635 11.2 223 l.SOa 3.60a Subsoil, sand, ["Road graders, loam, clay and < 9 wheel scrapers, mixture 3,352 8.8 200 I 8 drag scrapers.. 1.60b 2.80b fRoad machine, Sand and clay.. 3,654 6.06 ... ^ drag-scraper, [ 5 dump wagons.. O.SOc 1.00 Black waxy prairie subsoil 6,407 38.1 . . . Plows, graders 1.50 ^3.00 a 9-hr. day. b 8-hr. day. c convicts, mule team. Road Work with Power Machinery. Engineering and Con- tracting, May 15, 1918, describes some very low cost work done on a road leading north toward Pontiac, 111. The first 5 miles of this highway was changed from a narrow winding road to a level, well drained all the year road, 60 ft. wide between fences and 40 ft. wide between drainage ditches. Clearing. The work of clearing the right-of-way was started on May 1, 1917, and completed June 16, 1917, during which period 5.18 acres were cleared of a tangled mass of brush and shrubs and over 200 live trees from ,3 in. to 3 ft. in diameter. Trees were pulled by a 75-hp. caterpillar tractor using a 100-ft. cable. Two cable outfits were used, so that the tractor was not delayed waiting for hitches to be made. The cost of clearing the roadway, including labor, interest on investment and an allowance of 20% for depreciation of equipment, was $990.90, or $191.29 per acre. Grading. The grading was started on June 18, 1917. One 75-hp. caterpillar tractor was used to pull two Western graders, one 12-ft. to make the cut, followed by an 8-ft. to carry the dirt to the center of the road. A Western elevating grader pulled by a 75-hp. caterpillar -tractor was used in some places in mak- ing fills. However, on some of the deeper fills it was necessary to use some other method, in order to make time, and a 75-hp. caterpillar tractor was used in connection with a caterpillar land leveler. This land leveler is a tool used extensively in the West and is in reality a large scraper having a capacity of ap- proximately 3y 2 yd. With this machine the dirt could be taken up and carried across the road and then unloaded gradually or at one time, as conditions required. The gravel for the surfacing of the road was taken from a nearby creek with a dragline excavator which delivered it to a loading hopper. With the dragline excavator working steadily it was possible to keep the hopper filled, so that when the tractor trains came up, which consisted of one 75-hp. caterpillar tractor and six reversible trailers, they could be loaded without delay or without shoveling. 6 iT " *-<' - '- 1092 HANDBOOK OF EARTH EXCAVATION With this equipment a total of a little over 125,000 cu. yd. of dirt was moved in 75 working days. The total coat, including labor, interest on investment and an allowance of 20% covering depreciation on equipment, was $5,147, or 4.1 ct. per cubic yard. At no time were more than 8 men, including the superintendent, employed on the job. Horses or mules were not used at any time in the work. Road Embankments Over Marshy Ground. Highway embank- ments must often be built over soft ground where an indefinite amount of filling material sinks out of sight. It is difficult to build such embankments in layers because the ground is too soft to sustain horses or machinery. Many ingenious methods of overcoming the difficulties encountered have been devised, a few of which are described in the following paragraphs given in Engineering and Contracting, June 30, 1909. In general some of the methods employed in securing a good foundation for roads over soft ground are as follows: 1. By draining the subsoil so as to consolidate the ground as much as possible. 2. Where the soft material is not too deep nor its extent too great, a trench may be dug and filled with solid material to form a foundation for the embankment. 3. By consolidating the soft material by driving short piles and throwing stone in the side ditches to prevent the muck from oozing to the sides. By filling in with stone or gravel and sand until an embankment is formed resting on the solid ground, and with its top rising to the required elevation. 4. By distributing the weight over the soft ground by means of brush mattresses, timbers, poles, etc. By Draining. In most cases the firmness of the natural ground can be increased by digging wide and deep side drains parallel to the side of the intended road. In the case of bogs it is possible by draining the moss to condense it into a more or less solid peat. The undrained moss of bogs usually con- sists of about 10% of vegetable matter, the remainder being water. So it is necessary that the drainage be at a gradual rate to avoid carrying off particles of vegetable matter, thus causing the sides of the ditches to cave. The side drains are usually carried down into the solid ground, and it is well to cut them in a series of benches so as to expose as large a sur- face as possible to the sun and wind. The side ditches are placed about 30 ft. or more from the center line of the road, the distance depending upon the width of the berm which is to be left between the edge of the roadway and the side ditch. In no case should the berm be less than 6 ft., and it is better to have ROAD AND RAILROAD EMBANKMENTS 109.3 it more than this if possible. Side ditching destroys the natural sustaining power of the bog, and the drains should therefore be made a considerable distance from the line of the proposed road. Cross drains cut at right angles to the side drains are placed at frequent intervals, in most cases about 30 ft. apart. These cross drains should extend across the site of the intended road and beyond the side drains from 50 to 100 ft. By Consolidating the Soft Material. This was done in one case as follows : A country road supervisor was told to construct a corduroy road across swampy ground. Instead he took the logs and drove them endwise beside the road. These logs kept the muck from oo/.irig to the sides and the road proved very sat- isfactory. The logs were about 16 ft. long and were put down with a hand pile driver made of an elm butt, with three handles so that three men could be used on it. In another case a country road superintendent drew cobblestones in the winter time and threw them into the ditch alongside the road. In the spring the stones sank out of sight. The next winter he threw in more stones. These stones sank some but not out of sight, and as a result he had two walls on each side of his road so that the muck could not ooze to the sides. There has been no sinking of this road since. Filling in with Solid Material This method is often employed in the case of sink holes and for soft places of no great length or depth. In one instance a sink hole about 60 ft. long was filled in the following manner: A crossway above the water level was first constructed of 3-ft. second growth ash poles. On this cobblestones were placed to a depth of 2 ft. and flanked by boulders to hold the dirt. The stone was then covered with gravel to the level of the road on each side of the sink hole. Distributing the Weight Over the Soft Ground. Various methods have been employed for " floating " a roadway or rail- way embankment over soft ground. In one instance a railroad grade that has stood up for over 12 years without any trouble was built over ground so soft that a pole could be run down 30 ft. by hand, by first making a mat of trees and then placing earth on top of the mat. The trees were from 1} in. to 3 in. in diameter. In another case, a temporary road across a marsh of soft mud covered with high grass was built in the following manner: Drift wood was placed along the line of the proposed road, the bottom layer of sticks being placed lengthwise and the top layer crosswise. The high marsh grass was then cut and spread over the timber and covered with earth. Somewhat similar methods were used in the construction of a 1094 HANDBOOK OF EARTH EXCAVATION permanent road through a marsh. The marsh was about one mile, and was covered with water from a few inches to 2 ft. deep. The marsh was covered with wild rice about 8 ft. high, with stalks from }4 in. to % in. in diameter at the bottom. Through the central portion there was an open channel about 10 ft. wide, which widened out into small pools every few hun- dred feet. The channel and pools had from 3 to 4 ft. of water and about the same depth of decayed vegetable matter. The turf was about 1 ft. thick with from 2 to 6 ft. of soft black vegetable mould underneath, beneath which was a hard bottom of blue clay. Beginning at dry ground, an 18-ft. x 1-ft. x 1-in. board was laid lengthwise on the outside, 9 ft. from the center of the proposed road. Another board was laid in the center 6 ft. in advance of the first board and a third board laid on the opposite side 6 ft. in advance of the second board. The three longitudinal pieces were covered with 18-ft. inch boards laid crosswise and nailed as fast as laid to keep them in their places. Three more boards were placed lengthwise on these, one each side and one in the center, and nailed through into the boards underneath. Wild rice for a space of about 75 ft. on each side was cut down and forked onto this " floating " platform, making a compact cover- ing about 2 ft. thick. A turn around for teams was made at the end of the first 500 ft. of road. The first 500 ft. of roadbed was then covered to a width of 16 ft. with about 15 in. of stones, and on this was placed 3 in. of crushed stone. The road was built in 500-ft. sections, the turn around, which was made 36 ft. square of doubled boards, being moved to the end of each section. A pond about 200 ft. wide near the middle of the marsh was crossed by a bent bridge 50 ft. wide and by platforms the same as those used on the marsh, except wider. The road did not break through the turf in any place and only settled an average of 2 ft. This road was in service for over 25 years. In one instance a wagon road was constructed over a bog by placing a layer of brush forming a mattress. On top of this mattress was placed material taken from the side ditches, and on top of this was placed a layer of larger stone, the whole be- ing surfaced with 5 in. of gravel. In this case the surface of the bog was drained, care being taken to place the drainage ditches so that they would not impair the sustaining power of the natural crust of the bog. In another case a road was constructed over a soft, deep, wet and yielding swamp on a raft constructed of long poles. Long poles laid longitudinally with broken joints formed the bot- tom course, and a second course was formed by poles laid trans- versely. The two courses were then covered with brush, and on ROAD AND PxAILROAD EMBANKMENTS 1095 this was laid the earth and surfacing materials. The grade line was kept low and the filling was a clay loam. The black vegetable mould from the swamp should not be used for the earth covering. It is better to use clay loam, a gravelly loam, or clay. Sand when slightly moist makes a good foundation material. In some of these roads there has been remarkably little settlement. In the case of one road there was a settle- ment only of 2 in. after the roadbed had been subjected to heavy traffic for over a year. This embankment was built from peat bog at the elevation of mean high tide, but too soft to sustain a man without sinking in nearly to the knees. The road was 20 ft. wide with a 40-ft. carriageway and the grade line was an incline varying from 4 to 20 ft. above the surface of the marsh. The depth to the hard bottom was 8 ft. below the bog surface. Dry peat was used by George Stephenson to carry the Liver- pool & Manchester Ry. across Chat Moss in Great Britain, On the 4ry peat embankment was placed two layers of bundles to carry the ballast. One of the first railroads constructed in New York state was; carried across a swamp by spreading the pressure over a large surface by means of a wooden platform. In the construction of a short piece of railroad over float- ing land it was not possible to put in a trestle because the ground was not strong enough to hold the piling. Accordingly small willow brush, which abounded along the right of way, was cut and bound into mattresses, which were spread in a uniform binding plan across the right of way. Stringers to support the ties were then laid parallel to the line of the road. Dump cars were next pushed out on this road and sufficient dirt was brought up and spread to allow of flat cars being pushed out on the track with an engine. The fill made in this way had a 2 to 1 slope, and in the main the plan was successful, although in some places the roadbed failed to hold. In Cape May County, New Jersey, a number of roads have been constructed across marsh lands to connect seashore resorts with the main land. These marsh lands consist of large deposits of soft mud, in many cases 25 ft. deep, overlain by a sod or crust of sedge or grass roots. In many cases this crust is not of sufficient strength to support the weight of a horse. The meth- ods employed in constructing these roads were as follows: A foundation is laid of poles and stringers of sufficient area to support the weight of filling soil and pavement, together with the added weight of travel, without breaking down the meadow crust. The sides of the roadway are protected from wash by curbing and bulkheading on both sides of the road throughout. 1096 HANDBOOK OF EARTH EXCAVATION the entire length, and also by a continuous line of mud banks solidly compacted against the outerside of the curbing. In some of the latest roads constructed by the comity a " tie " is placed every 8 ft. under the pole foundations at right angles to the center line of the road. These ties are securely spiked or bolted to the piling supporting the side curbing or bulkheading and thus bind the two lines of curbing together, preventing the spreading of the roadway and at the same time carrying a part of the weight of the roadbed to the piling. After the pole foundations are properly laid, good soil is filled in between the lines of curbing until the required elevation is reached, after which shells and gravel are spread over the roadway until the finished surface is brought to an elevation of about 2 ft. above the mean high water level. The pavement that has given satis- faction on these roads consists of oyster shells spread 5 in. deep and covered with 4 in. of gravel. Somewhat different methods from those given in the preceding paragraph were used in the construction of a road in Atlantic County, New Jersey. This road was constructed across salt meadows, the mud varying in depths from 6 to 28 ft. The sur- face along the line of the road was mostly a floating sod, vary- ing in thickness from 2 to 4 ft.; below this was a semi-liquid mud resting upon hard pan. The latter, in a few places, was only 4 ft. thick, and below this was another stratum of soft mud. The first layer of hard pan was depended upon to support the roadway. The approaches to a bridge along the line of the road were piled, a water jet and hammer being used to put down the piles. In driving the piles the first resistance was met at a depth of 28 ft. ; at 35 ft. this resistan.ee disappeared and the pile with weight of hammer sank indefinitely. Accord- ingly the piles were only driven to a depth of 30 ft. The pit at this point, however, extended for only a short distance, and in most cases a solid bed of gravel, sand or clay was usually struck at a depth of from 10 to 20 ft. below high tide. After the line of road was located, sod banks 5^ ft. high, 12 ft. wide at the base, and 2 ft. wide at the top were built. This sod was taken from between the banks and was placed with the grass side out. The inside edges of the sod banks were 60 ft. apart. The space between the sod banks was then filled in with sand dredged from an adjoining bank and pumped through pipes for a distance of one-half mile or more. As the sand settled it pushed the mud sidewise until it reached an equilibrium or the sand rested on the hard pan. When the bed of sand was 6 ft. above the level of the meadow its weight was sufficient to displace the mud along the line of the road, and a good foundation was secured. There ROAD AND RAILROAD EMBANKMENTS 1097 were a number of silt ponds along the right of way of the road and at these points there was no sod for banks. Pine bulkheads were used at these places. After the sand fill had thoroughly settled the roadway was given the proper crown and surfaced with a coating of gravel. Methods in a way similar to those previously described are sometimes used in Yukon Territory, Alaska, in constructing roads over frozen muck and gravel flats. The ground usually consists of a layer of frozen gravel, next a layer of frozen muck and on this a layer of moss. A bed of 3-in. poles is laid length- wise on the layer of moss, then comes a layer of brush placed crosswise and on top is broken stone or gravel. The layer of brush is usually 1 ft. thick and the surface of gravel or stone is 6 in. thick. The top width of the road is 16 ft. in most cases. Such a road built over frozen ground costs about $3,200 per mile and can be maintained at much less cost than a road built along hill sides. In constructing roads of this type it has been found best to leave the moss intact under the bed of poles, as it protects the ground from thawing. The black frozen muck, having the consistency of solid stone, remains as a firm bed. The side ditches, usually 3 ft. deep, are cut either entirely in muck or partly in muck and partly in underlying gravel. These conditions vary with the thickness of the muck. The inside faces of the ditch are often banked with sod, thus furnishing an additional protection. In the construction of a side hill road it is necessary to cut into the moss blanket, and as a result the frozen muck is thawed out by the sun and seepage water and becomes a soft, slimy mass. The cost of maintaining such roads has been found to be so much greater than for roads on flat ground, that the latter are now constructed even if the distance between the termini is greater. Compression of Marsh Soil. When a bank is filled on marsh land there is first compression of the lighter marsh material between the heavier filling, then a shrinkage of filling material, and, third, a gradual settlement of the embankment, compact- ing and displacing the softer marsh that sometimes continues for many years. Eugene R. Smith, in Transactions American Society of Civil Engineers, vol. 37 (1897), gives .data on the compressibility of salt marsh at Islip, Long Island, N. Y., under the weight of an earth fill. This salt marsh (locally known as meadow) consists of a growth of salt grasses on mud just above the level of ordinary high tide. The mud consists of an accumulation of decayed seaweed and other vegetable mat- ter, and is very soft and compressible. The sod forms a cover- ing over the mud and distributes, in some measure, the pres- 1008 HANDBOOK OF EARTH EXCAVATION sure due to the weight of the filling material placed above. The pressure on the mud from the iill increases the .firmness of the mud by squeezing out the water. The specifications called for a fill 3 ft. high above the ordi- nary level of the meadow surface or about 3.4 ft. above ordi- nary high tide. The work was performed by an 18-in. centrifugal pump dredge, dredging sand from Great South Bay adjacent and from a canal dug through the meadow. This sand was a very sharp quartz and weighed from 2,875 to 2,956 Ib. dry and 3,037 to 3,118 Ib. wet per cu. yd. The percentage of compression of various depths of meadow sod ranging from 1.5 to 6.5 ft. thick during periods from 1 to 12 months are given in detail by Mr. Smith. The general average compression for all thicknesses was as follows: Months 1246 8 9 10 11 Percentage ....10.0 13.1 15.1 15.9 16.9 16.6 16.2 16.7 Meadows averaging 2.7 ft. thick ranging from 1.5 to 3.5 ft. inclusive, varied from the general average by minus percentages ranging from 2.3 for a period of 1 mo. to 5.6 for a period of 11 mos. Meadows averaging 4.7 ft. thick, ranging from 3.6 to 6.5 ft. inclusive, varied from the general average by plus percentages ranging from 0.0 for a period of 1 mo. to 2.8 for a period of 11 mos. Meadows over 6.6 ft. thick and averaging 6.9 ft. varied from the general average percentage of compression by plus percent- ages ranging from 0.0 for a period of 1 mo. to 1.3 for a period of 11 mos. Mr. Smith states that his experience in January, when the rise and fall of the tide was greater, indicated that great changes in tide level permitted an opportunity for the meadow to dry out and reduced its compressibility under filling. Railway Embankments. These are seldom built in layers ex- cept when they are made by scrapers or barrows. For high fills the usual practice is to build out from the end or to dump from trestles. Consolidating during construction usually being im- practicable, allowance for shrinkage must be made. This can be done in several ways : ( 1 ) By raising the height of crown above the established sub- grade by a percentage of embankment height. (2) By adding additional width to the standard crown width. (3) By combining methods one and two. (4) By adding a shrinkage percentage to the height of em- bankment, computing a new slope distance for this corrected height, thus increasing the width between slope stakes. The last method seems unusual and defeats the purpose of ROAD AND RAILROAD EMBANKMENTS 1099 shrinkage, as it adds width to the embankment where gravity and the action of the elements naturally provide it. In cases where sliding or sloughing is to be expected, it is better practice to increase the slope ratio. While raising the height of crown places the material where it is most needed, it has the disadvantage of making temporary humps in the grade line. If the fill is on maximum grade the allowance for shrinkage may cause that grade to be exceeded to a serious extent until the ultimate shrinking has taken place. This leads to the practice of adding additional width to the crown, the extra material being used to raise the tracks after subsidence takes place. In building a long, high levee, gravelly earth was dumped through a temporary trestle, and spread with a dragline scraper. The material was kept soaked with water from a pipe line on the trestle. For about 5 cts. per cu. yd. it was thus spread in layers and compacted. This is a relatively cheap method that might be used on railway embankments where subsidence is suf- ficiently objectionable to warrant the cost of consolidation. Subsidence of Embankments on Soft Ground. This is usually treated by continuing to fill until either the soft material is en- tirely replaced or until it is sufficiently compacted to carry the required load. Hence it often happens that railroad embank- ments contain much more material than appears on the surface. The importance of discovering this hidden embankment in val- uation work is obvious. F. J. Wright, in Engineering Record, Mar. 3, 1917, describes surveying work on the C. C. C. and St. L. Ry. to disclose the " lost yardage." The depth to which the different fills had .subsided ranged all the way up to 25 ft. The filled material also varied greatly, so that it was found expedient to use two methods in determin- ing the slope of subsidence (1) the excavation of test pits at the toe of the slope and (2) the drilling of test holes through the fill. The fills tested by the excavation of pits were either those which had subsided a comparatively small amount or those made of rock and other coarse material, making drilling im- possible. The pits were dug at the toe of the slope, from 100 to 200 ft. apart, between the points of no subsidence at the ends of the fill. The excavation of each pit was carried back several feet into the fill, the depth varying as the downward slope of the surface of the old ground toward the center of the fill. Test pits were impractical in sounding fills which had sub- sided more than 8 or 10 ft. The presence of water near the surface of the marsh or bog made the test-pit method more un- 1100 HANDBOOK OF EARTH EXCAVATION satisfactory. When these conditions were found, test holes were drilled down through the fill with an ordinary soil auger until old ground was reached. To facilitate drilling, pits were usu- ally dug at the toe of the slope, in about the manner shown in Fig. 3. The drilling outfit consisted of the following material : One 2-in. soil auger welded to a 6-ft. length of i x n/^-in. galvanized- iron pipe, the upset end threaded for a l^-in. standard pipe; ten 5-ft. lengths of } x 13,4-in. galvanized pipe, threaded at both ends; three 5-ft. lengths of % 6 x 2i-in. galvanized pipe (casing) ; eighteen l^-in- galvanized pipe sleeve couplings; two IG-in. Stillson pipe wrenches, and one length of 2-in. galvanized pipe ^ *' j Fig. 3. Typical Arrangement and Depths of Drill Holes. fitted with a standard li/4-in. galvanized pipe tec at the center (handle) . When the test holes were less than 6 ft. deep, the pipe handle was attached to the end of the auger. In the case of deeper holes the pipe handle was removed and pipe lengths were added as the depth of the hole demanded, the auger being turned with the pipe wrenches. The pipe casing was used only in fills containing cinders, sand, or coarse gravel, and was driven down until it passed through the material causing the difficulty in drilling. In putting down a test hole, the driller withdrew the auger at about every foot of depth, and the earth brought up was ex- amined and removed. The drilling was continued until material was reached which could be identified with the surrounding land. In cases where the filled earth and old ground were sim- ilar as to color and formation, roots and twigs in the latter aided in distinguishing between them. The estimated yardage due to subsidence of eight fills sounded ROAD AND RAILROAD EMBANKMENTS 1101 was 250,000 cu. yd. This work, which involved 1,090 lin. ft. of drilling and 270 cu. yd. of shovel work, was accomplished at a total cost of $305. Subsidence Investigations, C. B. & Q. R. R. W. W. K. Spar- row, in Engineering yews-Record, June 20, 1918, gives the fol- lowing: ' *!> ?', A hidden quantity of material 30% in excess of the apparent amount was found by the valuation department of the Chicago, Burlington & Quincy R. R. in a peat bog in northern Illinois. At a cost of $313 material amounting to 80,000 cu. yd. was found, mainly by means of test borings. The bog was under a 20-ft. fill which extended both ways from the bog. The entire extent of the latter was only 1,100 ft., and the appearance of the ground surface was no different from that on either side of it. To ascertain the extent and the amount of subsidence, test JOO- 40 J Fig. 4. Typical Cross-Section Near Midpoint of Bog. holes were put down by means of a 2^-in. wood auger attached to a %-in. gaspipe cut into convenient lengths. Trenching was resorted to at a few points, but did not give as satisfactory results as the test holes. Where undisturbed, the bog showed a top stratum composed of a black dirt which gradually turned into a stratum of brown crumbly material known as peat. Under this was a plastic mass, gray, which after a few feet turned to a greenish color. It was possible to push the auger through this stratum without turning it; the whole gave off a strong odor of marsh gas, and when the auger was withdrawn the hole closed at once. Un- der this mass a stratum of stiff blue clay was found, and at succeeding depths this material was found to become harder, with a tendency to contain gravel. Tests on either side of the bog developed a different forma- tion, in which no subsidence was found. The surface material was the same as for the bog. Under it a blue clay was found, containing streaks of yellow which gradually disappeared, leav- 1102 HANDBOOK OF EARTH EXCAVATION ing the material exactly the same as that found under the plastic mass in the bog. Fig. 4 shows the location of test holes, the strata revealed by them and the amount of hidden material compared with the vis- ible embankment. The yardage of embankment above the ap- parent ground line within the limits of the bog was 01,300. The yardage of hidden material was 80,000, showing the hidden quan- tity to be 30% in excess of the apparent quantity. To obtain the data, four men, receiving a total of $19.55 per day, worked 16 days, this cost amounting to $312.80. Fifty-two holes were bored to an average depth of 21 ft., and 25 to an average depth of 6.6 ft. The cost of the survey per linear foot of hole bored was 24 ct. The cost per cubic yard of hidden material revealed was 0.4 ct. Temporary Trestles. These are often used to carry construc- tion track in building embankments. Dumping from them saves the use of a considerable number of men who would be required to raise the tracks with jacks from time to time if no trestle was used. Most of the timber used in trestles remains buried in the fill. Trestles are a frequent source of difficulty. They are always in danger of injury from rocks or boulders in the filling material. Subsidence of the ground due to the weight of the growing embankment frequently destroys their alignment and usefulness. So many factors enter into the question of the econ- omy of using trestles that each case must be decided for itself. It is impossible to state any minimum height of embankment for which dumping from temporary trestles would be cheaper than raising the track. Engineering A'ews, Aug. 9, 1906, describes the method em- ployed to raise an old embankment. Earth was first dumped from the old main track and spread with a Jordan spreader. New track was laid on the newly dumped material and the em- bankment widened to slope stakes by throwing the track. The new track was then thrown to the final center and raised by tamping. Thirty men handled 30,800 cu. yd. of fill in one month. Their pay at $1.75 per day , was $52.50 daily or 3.4~ ct. per cu. yd. A trestle would have released 22 men, making a saving of 2.5 per cu. yd. or 32 ct. per lin. ft. of embankment built, which was not enough to cover the cost of the 10-ft. trestle required. On a higher fill a trestle would have saved its cost. Costs of Temporary Trestles. Engineering and Contracting, July 20, 1910, quotes D. J. Hauer in discussion of a paper on building embankments which was presented before the Am. Soc. of Eng. Contractors as follows: In regard to costs, I might say that in building a large number ROAD AND RAILROAD EMBANKMENTS 1103 of temporary trestles, and keeping very accurate records, where logs could be obtained on the ground at from 3 to 5 ct. per linear foot, and carpenter wages were from $2.50 to $3.00 a day, my ex- perience is that the cost of a trestle ranges anywhere from 1 to 8 ct. per cu. yd. Over low structures, where the amount of ma- terial to be dumped is not large, the cost runs frequently from 4 to 5 ct. per cu. yd., and maybe a, little higher; although in one case, near Savannah, Ga., I erected a long, low temporary trestle, at an average height of 8 ft., for 2} ct. a yd. But I was able to get my stringers by buying and reselling, so the cost was only $2 per thousand. For the short bents, placed on 18-ft. centers, I was able to get the timber off the right-of-way. But on that same work, where we were compelled to buy our longer timbers, the .cost was about 3 ct. a cu. yd. for a trestle about 28 ft. high. On one job in North Carolina, I erected temporary trestles, varying in height from 30 ft. to 50 ft., in some cases triple-deck in their framing, and they cost from 2} ct. to 5 ct. per cu. yd. for the material placed in the embankment. The cost of timber was 3 ct. per lin. ft., and carpenters were paid $2.50 a day. The amount of iron was small, being in the bents mostly. The stringers and ties were not fastened with metal. I have some costs of one structure, about 70 ft. high, where the price of timber was about 5 ct. a foot, and of labor $3 a day for the carpenter, and the average cost of the trestle was between 7 and 8 ct. per cu. yd. There were something like 150,000 cu. yd. Dumping Trestles on the Southern Ry. Engineering News, Nov. 16, 1916, illustrates several trestles in use on the Southern Railway. Railway fills are made chiefly by dumping from one or more lifts of trestle or by building one trestle and then jacking the track to grade. As is the case on most large grading jobs where several contractors are doing the work, both these methods are in use in grading the 50-mile second-track Southern Ry. relo- cation between Central, S. C., and Cornelia, Ga. Half a mile south of Ayersville, Ga., the trestle for a fill on the new line is built on the side of the old 70-ft. fill. This trestle was not anchored very securely, as Fig. 2 indicates. In dumping the 12-yd. cars were backed out on the trestle very carefully and just far enough to dump clear. The timbers, which are obtained near the right-of-way, are hauled to place and hoisted by hand, by ox team or by mules. Fig. 5 shows the design of a trestle at Seneca, S. C., in which some of the bents were wired together. Two especially good examples of the trestle method and the 1104 HANDBOOK OF EARTH EXCAVATION jacking method are found on this work. The heaviest fill is 150 ft. high, and it has been carried up more than UO ft., to date, by jacking the tracks from the first 18-ft. trestle lift. This work C ross -Section \ e v a -H o n Fig. 5. Trestle at Seneca, S. C., Used in Heavy Fill. Fig. 6. Trestle Built on Slope of Old 70-Ft. Fill. Two-Story Trestle. is near Toccoa, on the Lane section. Near Deercourt, Ga., a 105-ft. fill is being made from three parallel trestles of increas- ing height. Both these large fills are almost entirely borrow. Cost of Two Dumping Trestles. John C. Sessen, Proceedings ROAD AND RAILROAD EMBANKMENTS 1105 of the American Railway Engineering and Maintenance of Way Association, 1907, gives the following: These trestles were designed to carry a loaded train of 5-yd. dump cars before the trestle was filled, the engine being carried only after filling. Second-hand material, except bracing, was used. Two 8 x 16-in. stringers were used for 13-ft. spans. The stringers were recovered, the balance of the material was buried in embankment. Each bent consisted of two piles, cap and sway braces. Name of Job Big Shoal Little Shoal Length of trestle, ft 2,961 2,142 Average height, ft 40 35 Total cost of trestle $9,007 $5,853 Labor cost per lin. ft $1.30 $1.22 Material cost per lin. ft 1.74 1.51 Total cost per lin. ft $3.04 $2.73 Except as an approach to a higher trestle it does not usually pay to build trestles under 16 ft. in height. For trestles be- tween 20 and 60 ft. in height, the cost of trestle per cu. yd. of earth is about the same. Movable Trestles for Bank Construction. In Engineering Neivs, June 12, 1902, Joseph Wright describes and illustrates " A Method of Bank Construction by Dumping from Movable Trestles." The bank was to be about 1^ miles long and 6 ft. high for a railroad, over practically level ground. A trestle was built in sections 17 ft. long; the side on which the earth was dumped being closely sheeted with plank. Each section of the trestle rested on two long wooden skids, so that one team could shift each section of the trestle when it became necessary to move. Let it be noted, however, that if the embankment had been much over 6.5 ft. high the pressure of the earth against the plank sheeting would have shifted the trestle without the aid of a team; and means would have had to be provided to keep the trestle in place. This is an ingenious method, and enables a very long embankment to be built without leaving any timber in the bank. A method well adapted to similar conditions, but where the bank is high, is described and illlustrated in Engineering News, Jan. 16, 1902. A fill % mile long and 60 to 65 ft. high was to be made over practically level ground. Instead of trestling, the contractor had a light movable steel bridge made with a span of 150 ft., and 14 ft. between the trusses, the weight being about 40 tons. One end of the bridge was supported by the bank, on rollers; the other end was supported by a wooden tower or trestle 60 ft. 1106 HANDBOOK OF EARTH EXCAVATION high, made with bents, each having three " stories." The tower was 16 ft. wide on top and 25 ft. wide at the bottom, and it rested on wheels running upon rails 25 ft. apart. Guy ropes prevented overturning from wind pressure. By using block and tackle, one team of horses can shift the trestle with the bridge a distance of 30 ft. in three hours' time. A train of 12 dump cars (3 cu. yd. each) running on a 36-in. gage track is hauled by a locomotive. Three cars are dumped at a time, then the train is shifted, and three more cars dumped exactly where the first three stood. This dumping in one place is supposed to pack the earth and prevent future settlements. Thus far settlements have not oc- curred. The material is clay, and the steam shovel, working night and day, is loading about 1,600 cu. yd. every 24 hr. Had a temporary trestle been built the cost for timber would have been double the cost of the movable steel bridge and tower. These two methods of saving timber in trestling for fills (where timber is scarce) illustrate the possibilities of great sav- ing in cost when the contractor has a full knowledge of his business and a goodly share of ingenuity. The author would suggest that the first movable trestle method might be used even for very high fills, simply by building the fill up in layers of say 8 ft. thick the full length of the fill; and by so doing a more com- pact embankment would be secured. Cost of Carpenter Work on Trestles. In building an embank- ment 16 ft. high across Otisco Lake, N. Y., the author used round unsawed timber with two posts in each bent; the caps were sawed and the beams between bents upon which the rails rested were also sawed timber that was saved and used again and again. In this way the cost of trestling was made very slight. With carpenter wages at 25 ct. per hr., and labor at 15 ct. per hr., the cost of framing and erecting the trestle was $6 per 1,000 ft. B. M., or about l/ ct. per lineal ft. of heavy timber. Additional costs are given in my " Handbook of Cost Data." A Wire-Rope " Trestle." V. L. Ingle, Jr., in Engineering and Contracting, June 1, 1910, gives the following: Usually two methods are employed in making embankments where locomotives and dump cars are used. The first method is to lay the track on the ground, and, by dumping alternately to right and left, jack up the track until the required height is reached. This method is most economically employed where the ratio of length of embankment to height is 25, or more, to 1. The second method is to build a trestle and make the fill by dumping from it. Building trestles is expensive, and, if the material to compose the embankment contains a considerable pro- ROAD AND RAILROAD EMBANKMENTS 1107 portion of large rock or boulders, there is always the danger of carrying away a bent or otherwise seriously injuring the struc- ture. On a piece of heavy railroad work in the South where the embankments were high one of the embankments to be made contained about 115,000 cu. yd., reached a maximum height of 57 ft., and was slightly over 800 ft. long, from grade point to grade point. To build a trestle would have cost between $6,000 and $8,000, and, as the material to make the fill was mostly rock, the chances were very great that a part of the structure would be carried away before the completion of the work. To avoid the necessity of constructing a trestle, the following scheme was adopted: The cuts at both ends of the embankment were opened up in Fig. 7. Side View of Wire Rope Trestle for Making Large Fill. the usual manner with carts for about 60 ft., as indicated by the dotted lines in Fig. 7. At points, approximately 50 ft. from each grade point, deadmen were sunk, and two 1^-in. wire cables, spaced 3 ft. 6 in., were stretched from one to the other and hauled as taut as possible. At points about equally dividing the fill, three timber bents were erected, as shown in Fig. 7. These bents were made from timber cut on the right-of-way. Their construction is shown in Fig. 8. Caps were about 8x8 in. x 6 ft. and sills about 10 x 10 in. As this timber was cut on the ground, the dimensions varied slightly. In erecting, the tops of the caps were brought to the estab- lished grade line, and the sills were sunk in a trench 3 or 4 ft. deep, which was backfilled with rock or earth. This steadied the bents and prevented their kicking out at the foot, under the impact of the dumped material. From the caps, 1-in. guy wires 1108 HANDBOOK OF EARTH EXCAVATION were run out at angles of about 45, in order to clear the dump- ing of material as far as possible, and fastened to deadmen. The main cables were then fastened to the caps by wire lashings and the ties placed on them, every third or fourth tie being lashed to the cables. The rail was then laid on the ties, brought to the established grade line, and they were laid far enough ahead to accommodate the length of train used. The method of operation was as follows: A train of loaded cars was backed onto the approach fill, and, at the point where the cables left the fill, were dumped, the first car on one side, the second on the other side, alternate cars on alternate sides, until the entire train was unloaded. The train was then run back on the approach fill and the cars righted. Dumping the cars on Fig. 8. Details of Timber Bent for Wire Rope Trestle. alternate sides balanced the weight on the cables, prevented the overturning of the train and made the fill about equal on both sides of the track. All cars were dumped before their loaded weight came on the cables, only empty cars being supported thereon. Little or no shoveling of material was required, most of it sliding to the bottom of the fill, and what little remained was generally used -in jacking up the track. As the bents were approached, more or less care was exercised to prevent their being injured, but no more so than on any other trestle. The work was carried forward in this manner until the ravine had been spanned, after which it was widened out in the usual way. In building the trestle it was assumed that the deflection of the cables at the center of a bay would be about 5% of the span, but, by jacking up the track as the embankment was made, the deflection was reduced to about 3%. When dumping at the center of a 200-ft. span this gave about a 6% grade for a dinkey engine to start an empty train on, and was not prohibitive. ROAD AND RAILROAD EMBANKMENTS 1109 The plan described left very little material in the dump, saved the main cables, guys, and caps, and was much more quickly and cheaply carried out than would have been the erection of an all timber trestle. The writer left for other work before the com- pletion of this fill and so has no exact data as to cost. Figur- ing maintenance at the same rate as during his connection with the work, and barring accidents, the cost should have amounted to about 3 ct. per cu. yd. of embankment. A Suspension Bridge for Making Fills. Engineering and Contracting, May 19, 1909, gives the following. The bridge con- sists of two towers, a fixed standard cableway tower at the far end of the embankment, and a portable steel structure on the advancing end of the embankment, both supporting a suspended track. The movable tower is 25 ft. wide across track, 20 ft. wide in the direction parallel with the track, this w.idth decreas- ing to 12 ft. at the top, which is some 70 ft. above ground. The tower (Fig. 9) moves on a 20-ft. gage track, laid on the fill. The movement is by skidding, horizontal steel plates being at- tached to the feet of the tower legs. At the top of the tower are special saddles for the cables. The cables are spaced 12 ft. apart and extend from an anchor- age back of the stationary tower to an adjustment back of the portable tower. They are 2^4-in. wire rope cables. They carry suspenders which support the track platform; these suspenders are spaced 12 ft. apart on each cable, and are kept to proper spacing by connecting bars ( two 4^ x %-in. steel straps ) . Each suspender consists of a 6-in. trolley sheave having strap hangers on each side which support a single-sheave block. A %-in. steel cable is run through this block and supports in its bight another single-sheave block, which attaches to a staple bolt. The staple bolts of successive hangers run through and support the platform girders. The block and tackle construction of the suspenders per- mits their length to be adjusted vertically so that the track platform can always be kept level. The platform girders are across-track, one end being supported by the suspender from the right hand cable and the opposite end being supported by the suspender from the left hand cable. These girders carry two lines of stringers on which are laid the ties and rails of the dump car track. In operation the fill is started at the portable tower, the cars being backed out from the solid embankment onto the suspended platform track and dumped, a car at a time, just at the top edge of the fill. By this arrangement practically only empty cars are carried by the suspended platform. At the start of work the platform is suspended quite close to the tower, but as the em- 1110 HANDBOOK OF EARTH EXCAVATION KOAD AND RAILROAD EMBANKMENTS 1111 .O.lt ,. .0,21 T *-*- r *j .> !'. - i- I < 5 I ^ *" ^ ^ w "O o g CO Q -r CC < CU Q. O to c 3 1112 HANDBOOK OF EARTH EXCAVATION bankment is filled out the platform is moved away from the tower. This aerial cable bridge is handling some 1,200 cu. yd. of ma- terial per day, this being not the limit of the bridge, but the maximum which can be excavated daily. This plant, requires no Fig. 11. Details of Cable and Hanger. power other than that of the locomotives used for hauling ma- terial trains. It is readily dismantled and transported. Its salvage value is large. Further details of this cableway and suspended bridge are given in Engineering ~News, Apr. 22, 1909, as shown in Figs. 10 and 11. ROAD AND RAILROAD EMBANKMENTS 1113 Details of a Suspension Dumping Bridge. Engineering News, Nov. 20, 1913, gives the following: Each tower is composed of a pair of A-frames, braced together and carrying a heavy built-up cap. Upon the caps are placed cast-iron saddles for the two cables, which arc of plow steel, 2 in. diameter. On the anchorage sides, 'the cables are led to dead- men embedded in the ground about 150 ft. from the tower. Near the top of the tower they are connected by a 1-in. steel tierod, and beyond this they diverge at an angle of 30 to the anchor- ages. The cables are 10 ft. apart, and at intervals of 10 ft. there are suspenders or hangers secured to hooks clamped on the cables. prow sfeel cable 2 'Sheave ***' Jt'Pfow sfeel \ cable hangers MfntX* J Height to * !... Clear ; Contractors Locomotive I" Tie Rod Plan (SmafferScafe) .NI*S Fig. 12. Suspension Dumping Bridge for Building Embank- ments; Louisville & Nashville R. R. These suspenders are four-line tackles of %-in. steel cable, having the upper block hooked to the clamp on the main cable and a lower block hooked to a belt in a floorbeam 10 x 10 in. The stringers for the track ties rest on the beams. Each stringer is made up of two timbers 3x12 in. The track is laid for a length sufficient for six small dump cars. The first section of the floor is supported upon small bents, the bridge floor be- ginning where the height becomes too great for such bents. A Suspension Bridge and Its Cost. J. D. Mooney in Engi- neering and Contracting, Oct. 2, 1907, gives the cost of a " cable trestle" used in making a 175,000 cu. yd. fill on the Lake Erie and Pittsburgh Ry., at less than 1 ct. per cu. yd. Roebling galvanized bridge cable, 2^4 in., was used. The an- chors were 400 ft. apart, and an A-frame was erected to support 1114 HANDBOOK OF EARTH EXCAVATION the two cables in the middle; this made each span 200 ft. The anchor at the north bank consists of a log, 18 ft. long, 24 in. thick, imbedded in solid rock. Two eyebolts screw into the log and are fastened by heavy nuts over 8-in. cast iron washers. Connecting with these eyebolts are two 10-ft. chains with 10-in. links made from 2i-in. iron. These chains were put in to keep the cables from twisting by covering the chains with heavy weights. Two 3-in. turnbuckles, with a spread of 3 ft., made the connections between the chains and the cables. The cables were leaded into the turnbuckles. These turnbuckles, which were forged especially for this work, were used to take up the slack in the cables. The anchor at the south end consisted of a log, 25 ft. long and 24 in. thick, placed in a new fill of sandstone, 10 ft. deep. Three-inch planks were driven in front of the an- chor, two eyebolts, 22 in. long and 2y 2 in. in diameter, were screwed into the anchor log and fastened with nuts over cast washers, 8 in. in diameter and 2 in. thick. The eyebolts con- nected with clevises by means of 3-in. pins. The cables were leaded into these clevises. A rise of 1 ft. in 3 ft. brings the cables up to grade and to the end timber supports. The A-frame which supports the cables in the center is made of two bents of four timbers each, total height 92 ft. The lower 50 ft. of the frame is made of 10-in. round timbers, and the upper 42 ft. of 8 x 8-in. square timbers. The cables on the top of the A-frame are 8 ft. above grade. The bents rest on 10-in. mud sills. They have a batter of 1^ in. to a foot. The frame is 32 x 26 ft. at the bottom. A train consists of from six to twelve 4-yd. cars. These are emptied at the south end of the ravine and are pushed out onto the cableway as fast as they are emptied. The car rails are spiked to ties which rest on stringers. These stringers rest on 8-ft. logs fastened to the cables with U bolts. The cables are 7 ft. apart. Most of the fill is being made from a sandstone cut about a half mile distant. This sandstone has a slope a little steeper than 1^ to 1. The following is the actual cost of the cableway: 1,000 ft. 2}i-in. Roebling galvanized bridge cable.... $ 600.00 Eyebolts, 2^-in., with clevises, for both ends 2 turnbuckles at north end, 3-in 2 chains at north end, 10 ft. long, 2V 2 -in. iron 4 cast washers, 8 in. dia., 2 in. thick Timber for A frame. (All other timber was ob- tained on ground.) Upper was 42 ft., 14-ft. timber, 8x8 in. All bracing and cross ties. 3,200 ft. at $34 per M. (delivered) .- Lower 50 ft., round timber, 56 ft. long, bought in ^ r ee Team work for hauling round timber and pulling timber to place for erecting 6&.OU ROAD AND RAILROAD EMBANKMENTS 1115 Carpenter labor on A frame and end bents on bank 231.40 Time of superintendent 60.00 Common labor: Digging trenches for anchors and putting up cable- way 112.00 Nails and iron in A frame and bents 29.40 Total cost of cableway $1,531.76 A conservative estimate on the probable cost of a timber tres- tle for this opening, figuring on square 8 x 8-in. timber cut from native timber, gives the following cost: ft. B. M. (including posts, caps, bracing, stringers, etc.) at $26 $2,548.00 Labor putting up trestle, $6 per M. ft 588.00 Spikes 98.00 Drift bolts 40.00 Total estimated cost of trestle $3,274.00 The wages were probably about $3 for carpenters and $1.50 for laborers per 10-hr, day. Dragline Excavators for Railway Grading. Engineering and Contracting, June 4, 1913, gives the following: In double track construction, on the Chicago, Milwaukee and St. Paul Railway, between Andover and Groton, S. D., a fill 5 miles in length and averaging 20 ft. in height was made from natural surface to subgrade by means of dragline buckets which took the material for making the fill from side borrow pits. By this method slightly over 900,000 cu. yd. of material were placed in the fill in three months' time. At times as many as five machines were in operation. The booms of these machines ranged from 50 to 100 ft. in length. When in service the buckets of the machines were dumped, on the average, once a minute. The buckets used ranged from 2 to 3i cu. yd. capacity. The largest machine made 3^ cu. yd. of fill per minute when in service. This method seems to have a wide range of usefulness on rail- way work. Haulage Equipment Eliminated by Dragline Excavators. Engineering News-Record, June 28, 1917, describes work on the Lorain, Ashland & Southern R. R., south of Wellington, Ohio. Nothing heavier than an 8-ft. cut was met on the first three miles. The dragline machine borrowed for the fills and wasted the cuts, swinging about GO ft. of each end of each cut onto the adjacent fill. On the fourth mile, however, a cut 3,000 ft. long, 1,100 ft. of which averaged 19 ft. in depth, threatened to dis- place the dragline for other equipment. The material from this cut could not be placed in embankment economically and so was wasted. 1116 HANDBOOK OF EARTH EXCAVATION The dragline in making the cut rode the center line, swinging the material into spoil banks on both sides. Only one move through the cut was required. The dragline worked to a 0.57% grade, and on a 40-ft. curve the entire distance and handled approximately 40,000 yd. of heavy, yellow clay and blue gumbo during the six weeks re- quired to complete the work. The slopes were cut from a 20-ft. base one to one and required no hand dressing. Some sliding due to frost action has occurred, but the work compares favorably with similar work done by steam shovel. The south approach is a fill 2,300 ft. long, with a maximum height of 28 ft. built on a temporary grade of 0.7%. About 48,000 cu. yd. of material was borrowed from pits on either side, having widths of from 30 to 80 ft. and a maximum depth of 14 ft. Two moves through each pit were made, except for a short distance at the small end of the 'fill. On the first move, near the outside of the pit, the machine took out the material and placed it about halfway to the center line. On the second move this material was recast into the fill and the remainder of the pit made. At the high end of the fill during the second trip the machine climbed the side of the fill in order to cast to the top. From 10 to 20% was allowed for settlement, as a great part of the material handled was from low-lying ground saturated from spring rains. An early and thorough settlement of the fill occurred, and only ordinary maintenance attention has been required since. The land purchased for the borrow pits cost $250. The expense of temporary trestles was saved; and al- though some of the dirt was handled twice, the dragline did away with the usual transportation equipment and force. Building Railway Embankment with Hydraulic Dredges. Engineering and Contracting, in the issue of Feb. 9, 1916, gives the following: The method described is employed by the Chicago, Burlington & Quincy R. R. for building embankment across sloughs on line rectification along the bank of the Mississippi River. Referring to Fig. 13, where the fill first appears above water, shields 10 ft. long and 2 ft. high are placed on each side as indicated for one side only at a. The sand is allowed to deposit until it is filled in as at b. Sand from inside the shield line is then shoveled over against the backs of the shields on the desired 2 to 1 slope, and the shields are jacked up as in c. When the fill again nearly covers the shields, the operation is repeated, and again a third time when the fill is about 3 ft. deep as in d. The whole shield line is then moved in about 6 ft., and similar operations follow ROAD AND RAILROAD EMBANKMENTS 1117 until the completed embankment has reached grade with a top width of 34 ft. for double track. One foot is the usual allow- ance for shrinkage, although in some cases more has been deemed necessary. E. R. Stevens states that this dredge embankment is 35 to 50% cheaper than steam shovel work. An earlier account of this work published in Engineering and Contracting says: On shore, about 12 to 20 men are required to handle the dis- charge pipe and the shields or guides. The shields are pieces of sheet iron 18 in. wide and 16 ft. long which are placed on edge in the sand at different locations so that the discharge will be held in little ponds until the material has settled. The handling of these requires considerable experience in order to Cross Section of Embankment Fig. 13. Building Embankments with Hydraulic Dredge. get the best results. The rate of output depends considerably upon the control of the discharge, so that the material will set- tle properly. The handling of the pipes must be done quickly so that the pumping can be as nearly continuous as possible. The output of the dredge varies from 3,500 to 4,500 cu. yd. per day of 24 hr. The conditions for dredging are ideal, the heavy sand pumps easily and settles readily and no unusual dif- ficulties have held up the work so that its cost has been very low. The embankment had to be leveled by teams before laying tracks. Building Approach Embankments, Columbia River Bridge. The following abstract of an article by E. E. Howard in Engi- neering News, Jan. 27, 1916, is given as it offers an excellent illustration of the sheerboard method of retaining hydraulic fills. About 2 miles fill were built, averaging 20 ft. in height. See Fig. 14. The contract was let to the Tacoma Dredging Co., of Tacoma, Wash., at its bid of 13.24 ct. per cu. yd. of the net volume in 1118 HANDBOOK OF EARTH EXCAVATION place. This company moved its dredge to the site, installed pipes and pumped in the first sand on June 9. By Nov. 20 all of the embankment south of Oregon Slough had been placed a total net volume of 821,000 cu. yd. The placing of this ma- terial occupied 160 days, or an average of about 5,000 cu. yd. a day. The material remaining in the embankment is a medium- fine sand, sharp and clean. Method of Making Excavation. The material was excavated from the Oregon Slough by means of a suction dredge of usual type, with a cutting head, and was transported to place by being pumped through a line of pipe 24 in. in diameter. The opera- tion was by electric power from the high-voltage lines of the Portland Railway Light and Power Co. The main pump on the dredge was operated by two 500-hp. motors connected to the Fig. 14. Bulkheads for Retaining Hydraulic Fill for Embank- ment Approach to Columbia River Bridge. pump by rope drives. The pump was of capacity to give a dis- charge through the 24-in. pipe at a velocity of 12 to 15 ft. per sec. Operation continued 24 hr. per day during the time speci- fied, and the dredge was actually running about 14 hr. per day. For periods of a few hours at a time the dredge pumped as much as 1,000 cu. yd. per hr. There was of course a very considerable runoff of sand from the embankment, as well as a certain amount of fine material which flowed away with the waste water, and it is estimated that about 250,000 cu. yd. more than the above net amount was transported. The discharge-pipe line was extended to a length of about 4,000 ft., working from the dredge alone. For the greater distances a booster pump was installed in the line to give additional impetus. This pump was operated by a single 1,000-hp. motor operating with considerable overload. The dredge and booster pump together transported through a maximum length of 9,000 ft. of pipe. Such long-distance dredg- ing into an embankment so comparatively narrow and high is believed to mark a record for work of this character. The pipe was of the ordinary riveted variety with slip joints made of ROAD AND RAILROAD EMBANKMENTS 1119 7-gage material on the pontoons and of 10-gage material else- where. It was moved about by teams and wagons. Timber Bulkheads for Earth Backing. The embankment was built up in steps by the use of timber bulkheads (Fig. 14). These were built of 6 x 8-in. posts, about 10-ft. centers, supporting 2 x 12-in. sheathing, surfaced both edges. The sides of the em- bankment were built up by these means in steps 8 ft. wide and 4 ft. high. The first bulkheads were placed upon the natural ground surface by driving in the 6 x 8-in. posts with a hand maul and setting the lower plank into a small trench so that the bulkhead sheathing extended perhaps 8 to 12 in. below the or- dinary ground surface. When the sand had been filled in about the top of such first bulkheads, posts for succeeding bulkheads were set in place and the lower plank placed so that it extended about 12 in. below the top of the first bulkhead below. These posts were tied back into the embankment by 2 x 6-in. ties spiked on near the top of each post and extending back to a short post, in front of which were placed a few pieces of lagging to offer additional resistance. The pipe was laid to discharge into the middle of the embankment so marked and was carried for- ward from the river, bringing the embankment up to the final grade and working away from the dredge. A framework of baf- fle-boards was placed under the discharging end of the pipe, causing the water to spread out and spill over the ground be- low and run forward, distributing the different sizes of material as the velocity decreased. At some convenient low point there was provided an outflow down the side of the embankment, for which the steps of the embankment were paved with plank to pre- vent wash. After sections of the finished embankments became thoroughly drained as the work proceeded, the posts of the bulkheads were cut away and the planks removed and carried forward for re- peated use. Parts of the posts and of the 2 x 6-in. ties there- fore remain in the embankment. The finishing of the slopes was done by hand with shovels, and the successive steps were so lo- cated that the upper corner of each step filled into the lower corner of the step below, to provide the proper slope. The ac- tual pumping and transportation of the sand in the hands of these contractors were the simplest parts of the work, and they found it economical .to permit a very considerable wastage of ;material where a reasonable amount of such wastage saved in the construction of bulkheads. Filling Trestles by Sluicing. Data on this will be found in iChapter XVIII. This is so cheap and satisfactory a method of building embankments that its possibilities should be thoroughly 1120 HANDBOOK OF EARTH EXCAVATION investigated before any other means of moving earth are con- sidered. Additional information on filling land with material pumped by dredges will be found in Chapters XV, XX, and XXI. Supporting Construction Track on Ice. According to Engi- neering News, Feb. 26, 1903, embankments over a slough, 500 ft. wide, on the Illinois and Mississippi Canal, were built during the year 1903 by carrying the construction track on ice. The slough consisted of very soft mud, overlain by 2.5 ft. of water. The embankment was 100 ft. wide on top and 14 ft. above the water. As ice covered the slough no trestle was constructed, but the railway track was laid directly on the ice. Short trains of cars were brought down and dumped three at a time, one on each side, until a bank was formed. The train was composed of 18 cars as a rule, but only 6 loaded cars were put on the ice at any one time. The ice settled under the weight of the fill, but the embankment was raised as fast as the ice settled. At Stillwater, New York, the construction plant on part of Contract No. 68 of the New York State Barge Canal was con- veyed across the Hudson River, a distance of 1,000 ft., by build- ing a track on top of the ice. A full description of this cross- ing is contained in Engineering and Contracting, June 9, 1909. The nearest railway station to the site of this plant was 6 miles away, and to avoid the necessity of hauling the plant over- land for that distance, the contractor conceived the idea of de- livering it by trolley on the west bank, and carrying it across the ice. The heaviest single piece x was a 70-ton steam shovel, which could be stripped to about 45 tons by the removal of the boom and dipper. There were also thi'ee locomotives each weigh- ing 18 tons, stripped to 15 tons. In audition there were hoist- ing engines, dump cars, drills, etc., some pi eces weighing as much as 12 tons. On Jan. 12 when the machine/y was delivered at the river bank, the ice was only 9 in. thick. 1$ was increased to a thickness of 10 to 14 in. by cutting holes in tbC ice and P um P' ing water upon it. For spreading the weight over a wide area, 8 x 1^ in ' y ellow pine timbers, 24 ft. long, were placed beneath the nam^'^ 6 railway spaced 15 ft. apart. In each space were placed two *-in.x8-ft. ties, thus making the supports 5 ft. apart At tU e west bank, where there was an abrupt descent, the ties and lorn* timbers were spaced much closer. The supply of 24-ft. timber was not sufficient to cover the whole distance- and near the west bank there was a stretch of 150 ft. over which the track was supported by ties alone, spaced 2.5 ft. apart. A hoisting engine was first hauled across and placed on the ROAD AND RAILROAD EMBANKMENTS 1121 opposite bank. A cable, 1,000 ft. long, stretching from this en- gine to the opposite bank was used to pull over the loads. By taking several turns with this cable around a spool on the drum shaft, the various machines could be transported while the men were on shore, and it was not necessary to risk the life of some one upon the ice when the heavy loads were being carried. Moreover, when once started, the loads could be quickly hauled across. It took about 4 min. to haul over a single locomotive. Under the weight of a locomotive the ice sank down from 6 to 7 in. and formed in wave-like undulations, and there was also a shattering and cracking. It was determined that a load of 15 tons appeared to be the maximum for ice 10 in. thick. The steam shovel was therefore taken over the highway for a distance of 6 miles, involving a week's labor. Fortunately, there was almost no snow on the ground and a thin layer of ice covered the surface. It was thus possible easily to haul the rails and to lay the track without ties, a few flat iron rods holding the rails in position. The shovel was moved for about $100 per mile. A Scow Bridge Instead of a Trestle. A scow bridge was used in the construction* of the Falcon River Dike, Winnipeg Dis- trict. This device was illustrated in Engineering News, Feb. 4, 1915. It is claimed that the successful bidders saved over $25,000 by using the scow method as compared to the cost of using trestles. The contractors used two scows in tandem. The track on the boats consisted of 90-lb. rails on a frame-work whose sills rested on, but were not fastened to, the deck. To mote forward, the scows were outhauled under the rail-support- ing frames by a cable parsing forward over a snatchblock at the outer end of the rail and back to the dinkey. Then the in-shore ends of the 90-lb. rails were moved to the outer end of the scows in the new position, and the gap filled in with regular 60-lb. rail as used in the rest of the supply track on the finished fill. The dike, 8,000 ft. long, containing about 230,000 cu. yd. of gravel, progressed rapidly, being practically completed in four months. The greatest depth of water was about 25 ft. Ma- terial was obtained from a gravel pit adjacent 'to the north end of the dike. Engineering News, Apr. 1, 1915, gives the following relative to a dumping platform for disposing of material on the break- water and part of the harbor work at Halifax, N. S. This plat- form, Fig. 15, consisted of a scow held by water ballast to constant level in spite of the tide. A plate-girder bridge, 40-ft. long was mounted at its forward end on a barge 40 x 8 ft. in size, and at its rear end on four or five cross-ties laid on the 1122 HANDBOOK OF EARTH EXCAVATION outer corner of the embankment. The spoil was brought in 16-yd. dump cars and dumped directly from this bridge. Three or four cars at the head of a train were run on the bridge, dumped and returned. The track was continued across the scow as a tail track. When the embankment had been built up high enough (4 ft. above mean water) in the space spanned by the bridge, the scow and bridge were simply hauled forward until the bridge Fig. 15. A Scow Bridge." came to a new bearing on a new outer point on the embankment, and the process was continued. The tidal rise was about G ft. To keep the bridge level, water ballast tanks were provided in the scow. These were pumped full as the tide rose, and pumped out on the fall of the tide, keeping the dumping bridge level with the embankment. Placing a Railroad Fill from a Pontoon Bridge. Engineering Record, Jan. 31, 1914, gives the following: In the double-tracking and grade-revision program being car- ried out by the Chicago, Milwaukee & St. Paul Railway in South Dak. a fill was built across a lake about 1,200 ft. wide, averag- ing from 30 to 40 ft. deep. The bed of the lake is a soft and seemingly bottomless muck, test piles driven to a depth of 120 ft. indicating no firmer material. The contractor, the Cook Construction Company, of St. Paul, intending to make the fill from side-dump cars, built a trestle across the lake, using 90-ft. piles. When filling was begun the weight of material forced the trestle out of line, and in fact tore it to pieces in two or three places. New piles were driven with the same result, and this happened five or six times. Two scows were then built, and 60-ft. timbers were provided for stringers to carry the construction track. The scows were so placed that one set of timbers spanned from the bank to the ROAD AND RAILROAD EMBANKMENTS 1123 first scow and another set reached from scow to scow. The fill- ing was dumped at the head of the bank, the empty cars being pushed ahead on the outer span. When the new embankment reached the scow the inner span and that scow were moved ahead. The scheme has worked very successfully. Constructing a Fill with a Floating Trestle. A novel method of constructing a fill across Patterson Lake on the Northern Pacific Ry. between Tacoma and Tenino, Wash., is described in Engineering News, Mar. 25, 1915. The width of the lake meas- ured along the center line was 1,350 ft. Originally it was in- tended by the contractors to make the fill across by dumping from a trestle, using three-pile bents with piles approximately 80 ft. long. Near the center of the lake they drove four test piles, 115 ft. long, and at this point it was necessary to cap the piles above the water and place frame bents on them in order to get the necessary elevation for dumping. For this construc- tion four -pile bents and four-post bents were used. The soft mud of the lake bottom heaved as the fill was de- posited, throwing the fill out of line and lifting the piles bodily so that the trestle collapsed, and the mud rose above the surface of the water for a considerable area. The trestle was then held in place on log floats and these were later replaced by pontoons carrying a trestle of framed bents, as shown in Fig. 16. Slop- ing aprons extending from the trestle to the sides of the pontoon to deliver the material to the sides. This floating trestle was kept ahead of the end of the fill, being connected to it by a 60-ft. span of trussed timber stringers. One steam shovel, loading into 12-yd. standard-gage air dump cars, started filling at one end on Feb. 25, 1913. On June 11 another shovel with 4-yd. narrow-gage dump cars replaced this machine, and the former shovel was moved to the other end. The material was mainly gravel and sand. For a single-track fill 761,000 cu. yd. were required. Afterwards, 72,000 cu. yd. were added to widen this road to double-track. This additional work was completed June 25, 1914. Cost of Widening Embankments. Engineering News, Oct. 27, 1904, gives an abstract of a committee report presented at the an- nual meeting of the Roadmasters and Maintenance of Way As- sociation, 1904, from which the diagrams here given are taken. The assumption is that material for embankment is to be ob- tained by ditching and widening cuts. The diagram, Fig. 17, can be used to study the relative costs of different methods of doing this work. The second, Fig. 18, can be used to advantage only in determining whether it is cheaper to make a long haul from the point where ditching is being done, than to waste the 1124 HANDBOOK OP EARTH EXCAVATION ROAD AND RAILROAD EMBANKMENTS 1125 material obtained from ditching and obtain the material for widening banks from a more convenient location. By examining the diagram in Fig. 17 it will be seen that the cheapest method of ditching where the material is to be used in widening embankments, and where such work is not done by simply casting across one track, is by a machine ditcher, pro- vided the machine, is so designed that it can load and dump 5 cu. yd. in not to exceed 2^ min., exclusive of running time, and can be operated by three men besides the train crew, and if the Fig. 17. Diagram of Costs of Railway Ditching by Various Methods, Haul up to 7,500 Ft. conditions are such that such a machine can be used up to a haul of some 1,200 or 1,300 ft. in very fair digging, or up to some 1,900 ft. in bad, wet digging. From this point on, a properly designed machine ditcher, so arranged that it can load a full train of material, used in conjunction with a plow and cable or other method for quick unloading, can be worked most economically. In both these cases of machine ditchers, it is as- sumed that the machines will be used enough each year to bring the cost for interest ,and depreciation down to the estimate given in the appendix, the number of yards handled having to be greater than estimated in case a more expensive machine is used than estimated on. 1126 HANDBOOK OF EARTH EXCAVATION In case a machine ditcher is not available, a study of the diagram will show the relative cost per yard by various methods, provided the traffic is such that the actual working time of work train is only about 6 hr. out of 10 hr. the men are assumed to work each day. Team Work. On light work banks can be widened very eco- nomically with teams and scrapers. This method can also be used to widen the base of heavy embankments, the filling being afterwards completed by work train or other means. The filling being compacted by the movements of the teams over it is less liable to settlement and unites closer to the old bank than by other methods. Work of this kind is usually let by contract, the price being from 14 to 25 ct. per cu. yd. 4 5 6~7 Miles of 9 II IB 13 14 ' 6 Haul Fig. 18. Diagram of Cost of Railway Ditching by Various Methods. Hauls up to 15 Miles. Casting. The cost of ditching by casting may in fair digging be taken at 10 ct. per cu. yd., where one cast will place the ma- terial in a suitable final location. If necessary to use one plat- form by which the material can be raised 6 ft. with the first and 4 ft. with the last handling, in order to place it far enough from the edge of the cut, the cost for such material will be increased about 6 ct. per yd., or to a total of 16 ct. per cu. yd. A descrip- tion of a simple portable platform is given under the heading " Work Train and Hand Loading." In both of these cases the material cannot ordinarily be used to advantage in widening embankments. Wheelbarrows. By this method the material excavated may be used to widen embankments, if conditions are favorable, and the cost is practically a constant to which a uniform addition is made varying directly with the length of haul. For fair dig- ROAD AND RAILROAD EMBANKMENTS 1127 ging it will be noted that casting is cheaper than any wheel- barrow work, and that casting with one platform is about the same cost as wheeling 125 ft. with wheelbarrows. If the ma- terial is merely to be carried across three or more tracks, where the traffic is so heavy that it is not desirable to lay gangways across the tracks, on account of safety, very fair results can be obtained by constructing boxes with two handles, similar to the handles on push or hand cars, on each end, and have two men carry each box across. This method, however, is more expensive than wheeling. Push Cars. As it is necessary to protect push car work by flagmen, the greatest economy by this method will be obtained by working as many men with two flagmen as can be worked to advantage. This is indicated by the three dotted lines showing 4, 10 and 16 men actually ditching under the protection of two flagmen. It is here assumed that 20% of the time is lost on account of the traffic, but that this 20% covers the time spent in trimming up the cut. On the diagram, the three dotted lines in- dicate cost per yard if the men shovel the material off the car; while the three full lines indicate the cost if the car is so ar- ranged that the material can be dumped, by placing an entirely separate box, open at one side, on the bed of the car, or some other suitable method. By such an arrangement, the cost per yard can be reduced some 3 to 4^ ct. over shoveling the material off the cars. Work Trains and Hand Loading. The diagram is plainly marked showing the method covered by each line, and it is only necessary to call attention to the fact that where only 60 cu. yd. are handled per trip, the lines are dotted lines, and full lines are used where 120 cu. yd. are handled per trip. In all cases with work train (except one) it is assumed that all the men em- ployed go with the train to unload, and for this reason the cost, with 50 men, handling 120 yd. per train, becomes less than with 100 men under the same conditions, after a haul of about 2,600 ft., or } mile has been reached. If, however, the work is prop- erly handled the whole number of men employed (where such large numbers are used) are not sent with the train, but are kept at work at the ends of the cut ditching with wheelbarrows, or possibly casting the material, where such can be done by the use of a platform, while part of the men unload. The cost will thus be reduced considerably, it being possible, by proper arrange- ments, to reduce the cost to almost what machine ditchers will accomplish. A portable platform for carrying on the work trains for use in cases where material can be thrown out of the cuts by two 1128 HANDBOOK OF EARTH EXCAVATION castings, consists of two posts 2x6 in., 12 ft. long, with two horizontal pieces 2x6 in., 10 ft. long, running into the bank to support the platform of five boards 1 x 12 in., 5 ft. long. The posts and horizontal supports are bored at intervals to permit adjustment of the height of platform. In a deep cut, a second scaffold may be placed above the first. This device was first furnished section foremen on the Southern Railway by Mr. W. A. Ford, Supervisor, but was found to be of such value as a time saver when trains were late, that ditching trains were equipped with them. One man on the scaffold can handle about as much dirt as two men can handle in the ditch. On this diagram the question of using two or more work trains with a gang of say 100 men loading, the unloading being done at a distant point by plow and cable, has not been considered, as work of such character would vary to such an extent with the local conditions, that it would necessarily have to be considered specially for each individual case. It may be mentioned, how- ever, that 100 men could load 1,000 cu. yd. of material already loosened and placed conveniently for loading, in four hours' actual working time and at that rate the total cost for one train amounting to say $22 per day, would be but 2.2 ct. per cu. yd. In order, therefore, to keep such a gang busy, a sufficient num- ber of trains should be used, if conditions, such as traffic, side track facilities, etc., .will permit. The whole question with work trains, therefore, resolves itself into equalizing the number and disposition of men employed, with the train service in such a way that one will not overbalance the other, and both will be in accordance with the requirements in regard to length of haul, traffic conditions, etc. Machine Ditchers. These may be divided info two general classes : ( 1 ) Ditchers which load a scoop on one or both sides and then run to the end of the cut to dump the material, and (2) those which load a full train of material and unload by plow or by hand. The first kind can be used to advantage only where the haul is comparatively short, while the second class is economical for a long haul. The requirements of a suitable machine ditcher of either class are that it shall be able to cut the full depth necessary, and close up to the ends of the ties in order to obtain a standard section ; that it shall be quickly handled with the least number of men practicable; that it shall have the .fewest possible parts likely to get out of order, and that it shall be capable of sloping the banks in fair shape either by a slope board or dipper under con- trol of the engineman, the slope board probably being desirable even with the dipper. With either class of machine, the dipper ROAD AND RAILROAD EMBANKMENTS 1129 or scoop should be as large as can be handled to advantage in order to reduce the cost per yard, machines of first class having very long scoops, while those of the second class have dippers somewhat similar to a steam shovel dipper of about % to 1 cu. yd. capacity. As in the case of steam shovel work, the engine- man or the man in charge of handling the scoop or dipper, should be thoroughly competent, as the cost per yard of ma- terial will be greatly increased if the shovel work is handled slowly. E 3-45678 Miles Haul. Fig. 19. Diagram of Estimated Time for Work Train to Make Round Trip to and from Place of Unloading; Exclusive of Time Consumed in Unloading. Filling and Tamping a Viaduct Embankment. Engineering News, Nov. 5, 1914, gives the following: The New York Connecting R. R. is carried over a part of Astoria, L. !., N. Y., by a viaduct constructed of earth filled and tamped between concrete retaining walls. These walls are held together by steel tie rods. These rods are encased in con- crete as rapidly as the earth fill reaches them, which delays the work of filling and tamping somewhat. The filling material is composed of sand, gravel and loam, ex- cavated at Sunnyside yards by a 2J-cu. yd. steam shovel, and hauled 3.5 miles in 11 -car trains by 18-ton dinkeys to the via- duct. Cars hold 3.8 yd. each, and 250 to 300 cars or about 1130 HANDBOOK OF EARTH EXCAVATION 1,045 cu. yd. are handled per day. The dumping track is car- ried by timber trusses resting on the concrete retaining walls. The steam shovel crew is composed of a steam shovel runner, a craneman, fireman, and 6 pitmen. Each of the 5 trains is manned by an engineman and brakeman. The dumping is done by a fore- man and 5 laborers. The earth after being dumped is spread in 12-in. layers and tamped with pneumatic tampers. These tampers are manufac- tured by the Ingersoll-Rand Co. and are of the " crown " model. Air for their operation is supplied by a compressor rated at 946 cu. ft. of free air per min., 100 Ib. per sq. in. pressure, driven by a 150-hp. motor. Air is distributed through 3-in. and 2-in. pipe to distances of 1,400 and 2,100 ft. each way from the com- pressor. The average number of men employed in spreading and tamping is 45 laborers, 2 foremen, and 6 tampers. Two machin- ists are employed for ensuring the smooth operation of the tampers, 20 of which are on hand. With this crew of 51 men about 20 cu. yd. per man-day are spread and tamped. The author would suggest that it would have been cheaper to spread the earth with a dragline scraper and puddle it with water. Cost of Transporting Men, Tools and Supplies on Railroads for Grading. Engineering and Contracting, July 8, 1908, gives the following : In carrying on construction work it is the custom of railroads to charge the construction certain rates of fares on the men em- ployed, and freight on tools and supplies. This charge against the new work is credited to the operating department. The following figures have been used by H. P. Gillette in esti- mating the cost of railroad construction. The figures of work done, and men, horses and tools and supplies needed are based on large jobs of construction, and are safe averages. The fares for men and the freight rates are those ordinarily charged by railroads to themselves and to one another. One horse plus 1^ men readily excavate and move 15 cu. yd. of earth per day. Hence allow SCO cu. yd. per month per horse and 250 cu. yd. per month per man. One man requires transportation at 1 ct. per mile, and freight on 200 Ib. of bedding, cooking utensils, tents, small tools, -etc. Hence for 100 miles transportation each way, or 200 miles round trip, we have 200 pasenger miles at 1 ct $2.00 1/10 ton bedding, etc., 200 miles at % ct. per ton mile.. .10 Total $2.10 ROAD AND RAILROAD EMBANKMENTS 1131 Since one man will excavate 250 cu. yd. per month, it costs $2.10 divided by 250, or 0.8 ct. per cu. yd., if the job lasts only one month ; but if the job lasts four months it costs 0.8 ct. di- vided by four, or 0.2 ct. per cu. yd., because in that time a man will move four times 250 cu. yd., or 1,000 cu. yd., and will only require transportation once at a cost of $2.10. Other months are in proportion. For any other haul than 100 miles multiply accordingly. Each horse requires the following equipment: Lb. % wheel scraper, at 500 Ib 250 % wagon, at 2,000 Ib 1,000 Tents, harness, etc 250 Total ' 1,500 Allowing 1C horses per car of 24,000 Ibs., each horse stands for freight equivalent to 1,500 Ib., hence: Lb. Equipment for each horse 1,500 Weight of horse 1,500 Total, 1% tons or 3,000 For each 100 miles of haul we have, therefore, 200 miles round trip; hence 200 miles X 1} tone X 0.4 ct.= $1.20. Since each horse moves 360 cu. yd. per month, we have $1.20 -^- 360, or 0.3 ct. per cu. yd., if the job lasts only one month. But if the job lasts four months we have 14 f 0.3 ct., or 0.075 ct. per cu. yd. Other lengths of time and other hauls are in pro- portion. Each horse consumes l/ ton of food per month; hence if food is hauled 100 miles we have % ton X 100 miles X 0.4 ct.= 20 ct. Since the horse moves 360 cu. yd. per month, we have 20 ct.-=- 360, or 0.05 ct. per cu. yd. for each 100 miles of haul. Summing up, we have the following costs : Cost per cu. yd. for transportation 100 miles and return. Duration Men Horses Food Total of Work Ct. Ct. Ct. Ct. 1 mo 0.80 0.30 0.05 1.15 4 mo 0.20 0.08 0.05 0.33 6 mo 0.13 0.05 0.05 0.23 8 mo 0.10 0.04 0.05 0.19 12 mo 0.07 0.03 0.05 0.15 Note If the haul is 300 miles, multiply by 3. If the haul is 500 miles, multiply by 5. If the haul is 1,000 miles, mul- tiply by 10. The above is for work done by wheel scrapers and wagons and carts, but for steam shovel work the following would be the ap- proximate cost for transportation: 1132 HANDBOOK OF EARTH EXCAVATION Tons 1 shovel 70 60 dump cars 120 Rail ;. 65 Cross ties (6. in. x 6 in. x 6 ft.) 75 ' Three small locomotives 35 Pumps, drills, etc .. . 35 Total 400 400 tons X 100 miles X 0.4 ct. = $160. Such a shovel as this will average at least 20,000 cu. yd. per month, hence we have $160 -=- 20,000, or 0.8 ct. per cu. yd. for transporting the shovel 100 miles. This is equivalent to 1.6 ct. for transporting the shovel the round trip of 200 miles, when the job lasts only one month. For four months the cost would be % of 1.6 -ct., or 0.4 ct. per cu. yd. Other months would be cor- respondingly in proportion. Such a shovel does not consume more than 60 tons of fuel and supplies per month; hence we have 60 tons X 100 miles X 0.4 ct. = $24. Since with this 60 tons of fuel there are 20,000 cu. yd. excavated, we have $24 -f- 20,000, or 0.12 ct. per cu. yd. With such a shovel there will never be more than 40 men engaged in operating the shovel, operating the dump cars and trains, as well as in making temporary roadways and repairing equipment ; hence each of these 40 men averages 500 cu. yd. per month, which is double the output where men are working with wheel scrapers, carts, etc., as above given; therefore the cost of transporting men per cu. yd. on shovel work is approximately one-half the amount given in the previous table. Summarizing we have the following: Cost per cu. yd. for transportation 100 miles and return. Duration Shovel Men Fuel Total of Work Ct. Ct. Ct. , Ct. 1 mo 1.60 0.40 0.12 2.12 4 mo 0.40 0.10 0.1*2 0.62 6 mo 0.26 0.07 0.12 0.45 12 mo 0.13 0.03 0.12 0.28 The above is for a haul of 100 miles, and for any other hauls multiply according to the length of haul. If the workmen are of a restless disposition, and remain only a short time on the job before quitting, the cost of their transpor- tation varies not with the length of the job but with the average time they remain on it. When they quit, of course their return fare is not paid. Cost of Railway Grading by Steam Shovel. D. A. Wallace, in Engineering and Contracting, July 27, 1910, gives a description of the methods and costs of steam shovel work, loading slag, earth and sand into cars for railway ballasting and grading. ROAD AND RAILROAD EMBANKMENTS 1133 Slag for Ballasting. This slag was loaded by a 45-ton shovel working against a 20-ft. face, into cars placed on a spur track on a 3% grade. The grade permitted the spotting of cars by hand while the engine was unloading the loaded cars. The great- est haul was 4 miles. There was no delay to the slag train due to meeting revenue trains. The slag was in alternate vitrified and spongy layers. The use of the light shovel necessitated some use of powder but not more than the ground gang could drill the necessary holes for and handle. Holes were drilled on an average 9 ft. horizontally into the face 3 ft. from the ground line and about 10 ft. centers. Rodgers ballast cars were used. The size of the slag permitted easy unloading. The train crew with the help of one of the gang did the unloading and sweeping off. The wages were as follows: Engineman, per month $125.00 Craneman, per month 90.00 Fireman, per month 60.00 Foreman, per month 65.00 Ground hands, per day 1.25 The daily expense was as follows: "f Engineman $4.80 Craneman 3.46 Fireman 2.31 Foreman 2.50 6 ground men 7.50 2 tons coal at $2 4.00 Waste and oil 0.50 Dynamite 0.93 Work train 25.00 Total per day $51.00 The slag cost $2 per car load of 40 cu. yd. or 5 ct. per cu. yd. Including this, the cost of loading, hauling and unloading was as follows per cubic yard: 6 cars, 240 cu. yd $0.262 7 cars, 280 cu. yd 0.232 8 cars, 320 cu. yd 0.209 9 cars, 360 cu. yd 0.191 12 cars, 480 cu. yd 0.156 Earth for Grade Raising. Loose earth was loaded into Hart convertible cars spotted on the main line. The shovel was cut in on both sides of the main line and cuts were widened. A 12-ft. face was worked. The dirt was unloaded by the railway com- pany in widening fills or grade raising, as was most convenient, depending on the progress of the gangs and the time of revenue trains. The contractor was paid 7 ct. per cu. yd. pit measure for dirt loaded on cars. The following costs were for loading alone. The shovel used was a 70-ton Giant with a 2-cu. yd. dipper. The wages paid were as follows: 1134 HANDBOOK OF EARTH EXCAVATION Engineman, per month $150.00 Craneman, per month 90.00 Foreman, per day 2.00 Groundmen, per day (6 worked) 1.50 Watchman, per day 1.85 About 1^ gal. of cylinder oil at 40 ct. per gallon were used per day and 2 gal. of black oil at 10 ct. per gallon. The daily ex- penses were as follows: Engineman $ 6.00 Craneman 3.60 Fireman 2.00 Watchman 1.85 Ground hands 9.00 Total labor $22.45 Cylinder oil $0.60 Black oil 20 Waste 0.10 1 ton coal 1.50 Total per day ...:.... $24.85 The shovel loaded 45 cars of 24 cu. yd. per car or 600 cu. yd. per day. Sand for Ballast. Two sand pits were opened up, one on each side of the main line, and the lead track to each pit was used as a loading track. A 60-ton Marion shovel was cut into one pit and a 45-ton Vulcan shovel into the other pit. Three work trains were used for spotting cars, hauling and unloading. Each crew handled different parts of the work depending .on the arrival of the unloading trains and the speed of loading. One crew usually spotted cars for both shovels. This was done very easily because of the frequent moves of the shovels due to the shallow face of the cut. The sand was a white sand containing about 20% loam. It made a very satisfactory ballast for light traffic. Hart con- vertible cars were used and were unloaded by a Lidgerwood plow on new track. A large amount of time was lost due to the slow running necessitated by the very rough track. The 60-ton Marion shovel, working 21 days in July, loaded 1,075 cars with 29,008 cu. yd. The number of days worked was 22 or 223 hours, during which time there were 91 hr. 45 min. delays distributed as follows: Cause. Hr. Moving shovel 23.9 Waiting for cars 53.2 Closing car doors 4.6 Coal and water 5.8 Derailments 3.3 Shovel repairs 0.9 Total . . 91.7 ROAD AND RAILROAD EMBANKMENTS 1135 The 45-ton Vulcan shovel working 7 days in July loaded 235 cars with 7,570 cu. yd. The number of days worked was 7, or 70 hr., during which time the delays amounted to 49 hr. 43 min. distributed as follows: Cause. Hr. Moving shovel 7.1 Waiting for cars 28.3 Tank repairs 7.0 Shovel repairs 7.0 Derailments 0.3 Total 49.7 The total yardage loaded by both shovels was 36,578 cu. yd. The cost of loading, transporting and placing this yardage in the track was as follows per cu. yd. Loading $0.040 Transporting 0.074 Surfacing 0.231 Fuel and supplies 0.064 Rental equipment -. . 0.069 Supervision 0.025 Total $0.503 The face worked averaged 8 ft. and the haul was 10 miles. In August the two shovels worked more nearly the same amount of time. The total working time of the 60-ton shovel was 26 days or 310 hours, during which time there were the following delays: 60-Ton Marion Hr. Moving shovel 43.0 Waiting for cars 82.5 Waiting for laborers 29.0 Waiting on track work 6.4 Miscellaneous 10.0 Total .. 170.9 45-Ton Vulcan Moving shovel ; 35.0 Waiting for cars 45.5 Waiting for laborers 20.0 Waiting on track work 15.0 Waiting for power 20.0 Repairing shovel 27.0 Miscellaneous 12.0 Total 174.5 Summarizing the work of the two shovels we have: 60-Ton 45-Ton No. cars loaded 1,268 1,046 No. cu. yd. loaded 33,486 30,710 Av. cu. yd. per day 1,272 1,121 Av. cars per day 48 4/5 40 Av. cu. yd. per car 26^ 28% 1136 HANDBOOK OF EARTH EXCAVATION The total yardage for the month for both shovels was 63,196 cu. yd. The cost of loading, transporting and placing this yard- age in the track was as follows: Loading '. $0.019 Transporting 0.046 Surfacing 0.150 Fuel and supplies 0.075 Rental equipment 0.054 Supervision 0.019 Total $0.363 Cost of Raising a Railway Embankment. Work on the St. Louis and San Francisco R. R. through the Alabopolya Swamp in La. is described in Engineering and Contracting, July 13, 1910. The material in the embankment was the black gumbo com- monly encountered in Southern Louisiana swamps. The work described consisted of raising the embankment and filling in the temporary trestling. The conditions were difficult. The track was laid following closely behind the trestle gang, and frequent use of the track by the bridge material train put the track in very poor condition. A great portion of the embankment built. by " station work" was partially washed out by high water, leaving holes 4 ft. deep for 15 or 20 ft. of track. The temporary trestles stood 12 or 18 in. higher than the approaches. This con- dition was due to the excessive settlement of the swamp soil and also to Ijeavy rains. The worst holes were cribbed up with ties and tree branches, but even then a great amount of delay was caused the unloading trains by derailment and trains breaking in two in attempting to get over the bad places. It was necessary to unload dirt at these places before the track could be surfaced, as the gumbo would not hold a surface under one trainload of dirt. In many instances cars were unloaded standing on track 18 in. out of level and 3 ft. out of surface in a distance of 10 ft. along the rail. Hart convertible cars were used and were unloaded by a Lidger- wood plow. Before dirt was unloaded on the fills it was necessary to jack the track up out of the gumbo. It was impossible to move the track with No. 6 Barrett jacks after the dirt was unloaded. In many instances it was found necessary to strip out the track before" it could be lifted from the gumbo with 12 No. 6 Barret jacks, resting on boards, per rail length. The grade on embank- ment was raised not less than 12 in. at any point. The unloading was planned so that when the first gangs were unable to get the track in shape ahead of the unloading or when they were not able to care for the dirt as fast as it came, the un- loading was done on the trestles, and as they were being filled ROAD AND RAILROAD EMBANKMENTS 1137 a gang was kept busy tamping the dirt in under the caps and stringers. Following a rain, the dirt packed hard and the cars and stringers were removed by the Lidgerwood and cable. The shovel pits from which the dirt for filling -was got, aver- aged a 15-ft. face and 1,600 ft. in length. The dirt was a sandy clay compacting very quickly in embankment. The pit was opened up along one side of the main line and track laid behind the shovel in the first cut and used as a loading track for the next cut of the shovel. More difficulty than usual was experienced in keeping the pit properly drained. Good drainage was very necessary to take care of the frequent and heavy rains common to the country. Three trains were used, 1 loading train, which handled the water cars for the shovel, 1 swing train which made the run of 12 miles to the front in 40 minutes and 1 unloading train. The unloading was started 12 miles from the pit. A sid- ing and water tank were located there affording water to the swing and unloading trains. About 25 minutes were generally consumed there in switching empties and locals. The work recorded was done from Sept. 12 to Oct. 16, 1907. The daily expenses were as follows: Loading, Transporting and Unloading: 1 teamster at $150 per mo $ 5.00 3 conductors at $100 per mo 10.00 3 brakemen at $75 per mo 7.50 3 brakemen at $60 per mo 6.00 3 enginemen at $100 per mo 10.00 3 firemen at $75 per mo. 7.50 3 engine watchmen at $60 per mo 6.00 1 hostler at $75 per mo 2.50 1 hostler helper at $1.80 per day 1.80 1 steamshovel engineman at $150 per mo 5.00 1 steamshovel craneman at $90 per mo 3.00 1 steamshovel fireman at $75 per mo 2.50 steamshovel watchman at $60 per mo 2.00 machinist at $0.35 per hour 3.50 machinist helper at $1.80 per day 1.80 blacksmith at $0.35 per hour 3.50 blacksmith helper at $0.20 per hour 2.00 car repairer at $0.25 per hour 2.50 1 car repairer at $0.275 per hour 2.25 1 carpenter at $0.275 per hour 2.75 1 pumper at $60 per mo 2.00 1 Lidgerwood engineer at $90 per mo 3.00 6 pit men at $2 per day 12.00 6 cablemen at $2 per day 12.00 Total wages $116.10 20 tons coal at $4 $ 80.00 Supplies 2.56 j ce 1.00 Water at 50 ct. per tank from city 2.00 10 gal. gasoline at 10 ct Total supplies $ 86.56 1138 HANDBOOK OF EARTH EXCAVATION 1 steam shovel rent $ 10.00 3 engines rent at $1.53 per day 16.59 62 cars rent at 50 ct. per day 31.00 1 water car rent at 50 ct. per day 0.50 1 spreader rent at $2 per day 2.00 1 Lidgerwood rent at $5 per day . 5.00 Total plant rental $65.09 Add 10% super, and 5% misc $40.15 Grand total $307.90 Note. The 5% misc. includes overtime, etc. '.' -i '-u 'il i'H{ .'' J-.jjY, f.,ijsl; flt.llJ V.mi:jV\,*j(C 12 (1%-cu. yd.) Troy wagons at $112.50 $1,350.00 24 drag scrapers at $5.56 133.44 36 No. 21/2 wheel scrapers at $36.75 1,323.00 1 elevating grader 920.00 4 (2,500-lb.) wagons at $55.00 220.00 8 (16-ft. x 24-ft.) tents at $38.63 309.04 2 (32y 2 -ft. x 65-ft.) mule tents at $149.30 298.60 2 Ingersoll rock drills at $312.50 625.00 1 (le-hp.) boiler on wheels, 2nd hand 300.00 10 (1-yd.) dump carts with harness at $46.00 460.00 4 (2-yd.) dump cars with harness at $30.00 120.00 100 steel wheelbarrows, 3 and 4 cu. ft. at $3.00 300.00 12 doz. round point D handle shovels at $5.25 ...... 63.00 4 blacksmith outfits, including a forge, anvil, and other tools at $40.00 160.00 12 doz. picks with handles at $4.00 48.00 Total cost of equipment $6,630.08 The dump wagons and grader were used only about two months, and did fair work in the territory where they were employed. 1142 HANDBOOK OF EARTH EXCAVATION They were not used for a longer period on account of the inability to get sufficient mules and teams to operate them. When the company started work they were advised that all the teams that would be required could be secured in -the community, but although $3 per day, or 50 ct. more than the ruling price, was paid, only 15 to 18 teams, and they not of the best, could be se- cured. It was then decided to purchase mules, and 45 teams were bought. The average weight of these animals was over 1,255 Ib. These teams were in almost continual daily service from August 1, 1912, to June, 1913. Only two mules were lost and it is estimated that there was not over 5% lost time from the mules in service. The cost of feeding the mules averaged 95 ct. per team per day. Hay averaged $25 per ton and oats 57.5 ct. per bushel delivered at the camp. The teams were well fed and were taken care of by a competent stable boss which accounts for the small percentage of loss in mules and in time. Organization of Forces. The organizations of the various forces were fixed and were called " standard " and were only varied when it was shown that the needs of the work demanded it. The " standard " wheel scraper force was as follows for hauls not exceeding 300 ft. Six wheel-scrapers with teams and drivers, two teams, two plows, one snatch team, one man dumping, one loader, one wheeler, one water boy when required and one fore- man. When the haul increased, the number of wheel scrapers was increased in order to keep the snatch team and other laborers busy. This was very closely watched by the foremen of the various gangs in order to keep up their record, as every dumper was supplied with a counter and the day's work reported. In this way a very close estimate could be made of the yardage moved. Drag Scraper Work. The " standard " drag scraper force con- sisted of six scrapers with teams and drivers, two teams to plow, one dumper, one loader, one foreman, and one water boy. The drag scraper work and the wheel scraper work were watched with great care to determine the economical haul. The drag scraper is efficient for very short hauls. Observation of the various hauls up to 200 ft. fully demonstrated the fact that for a distance of over 100 ft. the drag scraper was an expensive im- plement. Under 100 ft. it would do efficient work. Wheel scrapers ordinarily could be used where the drags could be used, and had the advantage of making about the same speed with about five times the load. As a general rule only a few drags should be used on work of this kind. Their advantage is in their cheap- ness, and for a small amount of work for short hauls the drag scraper is desirable. A gang of wheel-barrow men properly han- ROAD AND RAILROAD EMBANKMENTS 1143 died will do work about as cheaply as a drag, and in some in- stances at less expense. Assuming the haul for drag scraper to be 100 ft., a lively mule team to a scraper will not make over 1.3 miles per hr. on account of the frequent turns in loading, or about 6,900 ft. per hour. This is at the rate of 3.45 cu. yd. per hour or 34.5 cu. yd. per 10-hr, day per team. With a " standard " drag scraper force, and teams at $3 per day, 8 drags will handle 27.6 cu. yd. each per 10-hr, day at a total labor cost of $37.50 or nearly 14 ct. per cu. yd. For a haul of from 50 to 75 ft. the cost will not exceed 12 ct. per cu. yd. About 75 ft. should be the maximum haul with drag scrapers. Six drag scrapers with a shorter haul were there- fore established as the maximum to be used with the minimum haul. Actual observation of a 110-ft. haul with country teams indicated that under the 'best conditions only 25.5 trips were made per hr., or a speed of 83 ft. per min. The company teams, which were all well fed Missouri mules, made as high as 120 ft. per min. with drag scrapers on a haul of 150 ft. These results were ob- tained under the best possible conditions where the dumper man counted and reported every load and in addition the teams were under personal observation of the general manager. A few drag scrapers on every job of similar character are a good investment but the number in use should be limited. An injudicious foreman will often use them at the company's expense. Wheel Svraper Work. The "standard" wheel scraper forces, above given, were modified as the hauls increased, the number of wheelers increased to 8 and, possibly, with very long hauls, to 10 or even 12. In only one instance did the haul with wheelers much exceed 600 ft., and in this instance the haul averaged 1,350 ft.; ten wheelers only were available but they were able to handle 225 cu. yd. at a cost of 23.5 ct. per cu. yd., figuring teams at $3.50 per 10-hr, day, although all the teams which were actually used cost only $3 per day. With a haul of 415 ft. a careful timing of the teams indicated that they were making 4 trips in 20 min. An average of twelve trips per hour was made for the entire day. The wheelers were loaded to their capacity and therefore an average of nearly 60 cu. yd. per wheeler was secured. The wheeler force using only 6 wheelers cost $30 per day. The labor cost in this case did not much exceed 10 ct. per cu. yd. Wheel-Barrow Excavation. The wheel-barrow, when properly used, was a most useful, necessary, convenient, and economical tool. Three types of barrows were purchased: The ordinary railroad wooden barrow, the wooden frame contractor's barrow with steel tray, and the whole steel wheel-barrow with one-piece 1144 HANDBOOK OF EARTH EXCAVATION tubular bent handles. Barrows of 3 and 4 cu. ft. capacity were bought; the barrow holding 4 cu. ft. in general seemed to suit the work and could be handled about as easily as the barrow holding only 3 cu. ft. The ordinary wooden barrow gave very poor serv- ice. A few of the barrows with wooden frames went out of serv- ice, but the whole steel wheel-barrows were practically as good as new after 8 months' fairly good service. The barrows were painted when out of service any length of time. For side hill work and for open grade work the barrow gave very efficient service. Observations on side hill work showed that gangs of 25 men handled dirt at the rate of 8 wheel-barrows per min. for an hour with a haul of 21 ft. This would mean that they moved over 500 cu. yd. in wheel-barrows holding 4 cu. ft. Good runways were always provided so that the loads could be moved with the least possible waste of energy. The gangs were placed in the hands of efficient foremen who taught the men how to handle the dirt with the least possible loss of time. At all times it was the endeavor to have a " stand- ard gang" of not less than 25 men under each foreman. The work varied as the conditions necessitated. In some cases much drilling was required and in others, none at all. Dump Car and Cart Excavation. Four small dump cars with revolving bodies were found to be convenient and useful in short cuts and at the approaches to the one tunnel that was built. These cars run on a track of 30-in. gage and had a capacity of 2 cu. yd. The cars were particularly useful in small cuts and where the haul was long. The revolving body would permit the car to be dumped in building the fill ahead of it or it could be dumped on the side to widen the fill or waste the material. Light rails not being available, these cars were run on a track made of 4 x 4 oak timbers. The wooden rails required only a few renewals during their six months' service. Dump carts could be used economically only upon hauls about 100 ft. long, but two of the cars moved by mules could keep a gang of 10 to 12 shovellers continually busy where the haul was from 600 to 700 ft. In one cut alone it is estimated that two of these cars handled 15,000 cu. yd. of earth and rock with a maximum haul of 650 ft. at a cost not to exceed 20 ct. per cu. yd. The average gang, in- cluding drillers, was about 14 men and a foreman. This number of men loaded about 150 cu. yd. per day at a labor cost of about $25 per day. It took nearly three months to remove the cut. While dump carts could be used for the short hauls of 100 to 125 ft. efficiently, yet they were used to advantage where the maximum haul was 250 ft., provided the roadway was kept in ROAD AND RAILROAD EMBANKMENTS 1145 good order and several carts were used to keep a good sized gang moving. In one instance 6 carts were used in completing a fill and did the work very rapidly where the haul was approximately 150 ft. Six carts and 30 laborers moved 325 cu. yd. per day at an expense of approximately $47 or about 15 ct. per cu. yd. As a general rule the cost of handling earth and rock with dump carts and men was about 26 ct. per cu. yd., exclusive of the cost of explosives. Methods of Using Explosives in Soft Ground. In using ex- plosives it was difficult at first to get the desired results, as all the old time powder men believed in the single shot or two or three shot method rather than in the large blast. Moreover the experienced men that were employed had only used explosives to shatter and break up rock or very hard soil, so that it could be handled by either hand or steam shovels, and the old powder men at first tried to continue the use of that method, whereas, it was desired to throw as much of the earth and rock from the cuts as possible without resorting to further methods of removal. In general, in earth or soft rock where the cut at the center line was over 4 ft., the first line of holes was placed not more than 2 ft. above the center line. All holes were driven to a point 2 ft. below grade and usually about the same distance apart as the depth of hole to grade, except when the depth was greater than 1-5 ft. The maximum distance apart was 15 ft. If the hillside was steep and the lower side of the road bed at grade, one set of holes was sufficient. If the cut under ordinary circumstances was a through cut with a depth of cut of 2 ft. or more on the lower side, then a lower set of holes was drilled parallel to the first at the lower ditch line at points midway between the upper holes, so that there would be no question of moving the material out of the way. This did not materially increase the amount of powder used as 1 cu. yd. of soft rock and earth was moved with about 2 Ib. of powder. The soft rock usually was a decomposed granite or Carolina gneiss which was not hard to drill. The gen- eral tendency was to use too much powder. In putting down holes in earth and soft rock hand and ch'urn drills were success- fully used. Bibliography. " Railroad Construction," Walter Loring Webb; "The Catskill Water Supply of New York City," Lazarus White; " Railway Estimates," F. Lavis. "Relative Cost of Filling and Building Trestles," Trans. Eng. Asso. of the South, Vol. 12, 1901. " Settlement of the Embankment Between Squantum and Moon Island, Boston Main Drainage Works," Henry N. Carter, Jour. ASSQ, Eny. Soc., Vol. 1 1, 1892. 1146 HANDBOOK OF EARTH EXCAVATION " Second Track Construction and Improvement of Line and Grade from Madison to Bariboo, Wisconsin, Chicago and North Western Ry.," H. W. Batten, Engineering News, June 3, 1897; " Method of Crossing Marshy Ground on the Detroit and Milwau- kee Ry. in 1877," Eng. News, Nov. 21, 1901; "An Interesting Ex- ample of False Work Construction," J. F. Jackson, Eng. News, March 9, 1893; " Haslett Park Sink-Hole on the Grand Trunk Railroad," Ry. and Eng. Review,' Dec. 31, 1904; Long Fill Built from Borrow. ,;<{)> hv>uj-)h i ji.Ul. K^H CHAPTER XX DESIGN AND CONSTRUCTION OF EARTH DAMS . .fcxfttinMto'ii i>,ir,i i-ijwfi '*{) i!-:ro;i ; ? Design of Earth Dams. H. A. Hageman in the Stone and Web- ster Journal, Feb., 1916, gives the following: Earthen dams usually consist of ( 1 ) A bank of earth containing homogeneous material through- out, or (2) An embankment having a central core of masonry, con- crete, or a puddle of selected impervious materials, or (3) An embankment having a puddle or selected material on the water slope, or (4) An embankment resting against an embankment of loose rock, or (5) An embankment of earth, sand and gravel, sluiced into place by flowing water. The plan of construction adopted is dependent upon conditions at the dam site, the materials available and the design of the structure. Foundation. The dam site should be carefully selected and its location chosen only after the character of the foundation has been thoroughly examined by test borings. It is important that the dam be constructed on a stratum that is impervious or nearly so, and that suitable cut : offs be provided to prevent harmful leakage through the structure. The entire surface area within the confine of the dam should have all the undesirable material removed from the foundation. The depth of the excavation is dependent on the character of the material encountered and the judgment of the engineers. Any springs encountered should be diverted or drained. Materials. The best results are obtained from a mixture con- taining 70 to 80% gravel, having sufficient variety of sizes and the balance of clay to completely fill the voids. The use of clay alone or in large quantities is not recom- mended, as it swells when wet and shrinks in drying. The per- centage of clay to be used in the dam varies from 15 to 30%, the amount being entirely dependent upon the nature of the material mixed with it. That portion of the fill outside the puddled section should consist of sand, loam or fine gravel, carefully selected. No material which is liable to disintegrate or which is soluble in water should be used. It is desirable that a mechanical analysis should be made of the materials in the foundation of the dam and those of which 1147 1148 HANDBOOK OF EARTH EXCAVATION it is to be constructed ; also that the rates of percolation of water through the materials should be determined. Reference is given to the experiments of 1892 Report of Massachusetts State Board of Health. North Dike of the Wachusett Reservoir, Clinton, Mass., by F. P. Stearns. Trans. A. S. C. E., Vol. XLVIII, pp. 259-277. Eng. News, May 8, 1902. Cold Springs Dam Eng. News, March 7, 1907. The Bohio Dam, Panama, by G. S. Morison Trans. A. S. C. E., Vol. XLVIII, with discussion, by F. P. Stearns and others. -; ';!;;; Design. The design of earthen dams should not be based upon mathematical calculations of equilibrium and safe pressure, as in the case of masonry dams, but rather upon results Obtained from experience. The important factors to be studied to determine the profile of a proposed earthen dam are: ( 1 ) Selection of the dam site. (2) Character of the foundation. (3) Material available. (4) Percolation factor of the material to be used in con- structing the dam and that in the foundation. (5) Location and kind of core wall, if necessary. (6) Slope of upstream and downstream faces, including loca- tion and width of berms. (7) Height of top above high water. (8) Paving of slope above high water. (9) Location and class of construction of spillway, outlet and waste pipes, etc. (10) Placing of material. Hydraulic or dry fin. Profile Dimensions. The dimensions usually adopted for the profile are as follows: Top width, see formula below. Superelevation above high water, 5 to 25 ft. Upstream slope, not less than 3 to 1. Downstream slope, not less than 2 to 1. The following formula has been suggested for determining the top width. Till DESIGN AND CONSTRUCTION OF EARTH DAMS 1149 W = 1/5 h -f 5. W =r top width in feet. h = height of dam in feet. The top of the dam should be beyond the reach of all waves and the following formula by Stephenson is commonly used for deter- mining the height: 4 X = 1.5 F-f (2.5 V~ X = Height in "feet above high water elevation. F = Sweep of wind in miles in the longest straight line which can be drawn on the water surface of the reservoir. The upstream slope is made natter than the downstream slope for the reason that the natural slope of earth is less when wet than when dry. The upstream slope should be paved with stone or concrete to protect the dam from wave action and burrowing animals. The downstream slope should be paved or seeded. Core Wall. The subject of the kind of core wall that should be provided for an earthen dam is a much disputed question. When ^sufficient impervious material is obtainable to construct the entire structure, it is obvious that a core wall is unnecessary. When a core wall is necessary the type to be used should be carefully considered. English engineers are disposed to favor a puddle core wall, while American engineering practice inclines toward a masonry core wall, although many dams containing a puddle core wall have been built in this country. The core wall should, if of concrete, always be well reinforced and constructed upon an impervious foundation and extend up to the high water elevation. It should be well supported on each side by the embankment, and carefully placed in such a man- ner as not to distort or break the wall during construction. Puddle Core. The puddle core is usually less expensive than the masonry core. When properly constructed it is practically watertight and settlement of the embankment does not tend to rupture it. It also makes a better union with the rest of the em- bankment than the masonry core. Undoubtedly the best material for a puddle core is a gravel containing just enough clay to bind the parts together and make them water-tight. When the material jcannot be obtained in bulk, the component parts should be uniformly mixed dry, then wetted and worked to make a tough, elastic mass. The material should be deposited in thin layers and well rolled when suffi- ciently dry. 1150 HANDBOOK OF EARTH EXCAVATION The dimensions for a puddle core wall: Top and bottom thickness should in each included case be a matter of judgment with the engineer, whose decision with re- spect to the dimensions will be governed by the quality of the material available for the embankment. Modern engineering practice suggests that dimensions less than the following should not be used. Masonry Core. The chief objections to a masonry or concrete core wall are the danger of its having to withstand the total water pressure due to percolation from the reservoir through the up- stream slope and to the probability of being cracked from temper- ature changes or from the settlement of the embankment. Masonry core walls are usually from 2.5 to 6 ft. wide at the high water elevation and both surfaces are battered uniformly from the top to the natural ground surface and then are vertical to the foundation. The thickness at the bottom of the batter should be from one- sixth to one-eighth of the head of water on the dam. Placing the Embankment. When the material is not placed by the hydraulic process, it should be deposited in thin, level layers, wetted and rolled with a heavy power-driven roller. Before placing an additional layer of material, the last one should be wetted and harrowed to insure bonding with the next course. The upstream side of the embankment should be kept higher than the downstream slope for drainage purposes. The conditions best suited for an economical hydraulic fill are: ( 1 ) An abundance of water at an elevation or pumped to form a sluicing head. (2) An ample deposit of the materials for forming the dam, convenient to both ends and at an elevation to permit of the grades necessary to carry the material. It is customary to deposit the coarser materials near the slopes and the finer materials toward the center. The hydraulic sluicing method affords a safe and satisfactory method of constructing an earthen dam, since it segregates the puddle cores from all classes of soils and assembles them into a mass of marked uniformity. By this method the structure does not require a core wall and a large proportion of the dam when made from proper materials becomes puddle clay. The process has been used successfully in constructing many important embankments, and it has been suggested that it offers AND CONSTRUCTION OF EARTH DAMS 1151 a reasonable compromise between core walls of masonry and pud- dled clay. When the materials which are to be used in constructing the dam have been fully analyzed mechanically and the percolation factor is known, the most impervious material is placed next to the water line, the least impervious material being placed on the downstream slope where it will give stability and drainage. Slope Protection. The upstream slope above the low water line should be protected by a facing of rock paving. The stones should be laid on edge in a course of gravel. The least dimension of any stone should not be less than 8 in. Below the water line the slope should be covered with loose rock. All voids between the stones should be filled with gravel. The top of the embankment should be paved or sodded, as may be decided upon. The downstream slope should be covered with loam, and planted with a quick growing grass seed. All berms should have paved drains. Appurtenances for Dams. The waste water spillway is an es- sential part of the dam, and its location and construction should be carefully considered. Its location is somewhat dependable upon local conditions. The spillway, together with its abutments and wing walls, should, where possible, be founded on rock and constructed en- tirely of masonry well anchored to the earth fill, with cut-off walls of such dimensions as will preclude all possibility of water passing under or around it. The design should provide for a weir and wing walls of such dimensions that unusual floods can be easily discharged through the overflow waterway without coming in contact with or causing any damage to the earth embankment. It is important that all conduits, whether of metal or masonry, that are built into the dam, shall be supported on an unyielding foundation. Masonry cut-off walls should be built around the conduits at intervals, to prevent water leakage between the conduit and the earth fill. Permeability of Concrete and Puddle Walls in Earth Dams is discussed by W. D'Rohan in Engineering and Contracting, Jan- uary 18, 1911. He draws a comparison between conditions found by a board of engineers who were consulted as to the safety of the new Croton Dam and conditions found in the north and south dikes of the Wachusett dam. The proposed extension of the new Croton Dam was to be of earth with a masonry core wall of over 180 ft. in height. Under their direction, borings were made in 1152 HANDBOOK OF EARTH EXCAVATION several earthen dams with concrete and masonry core walls at right angles to the axis, and at such intervals as to show that in almost every case there was a continuous water plane extending from the water surface of the reservoir to the core wall, and on the downstream side to the lower toe having a maximum in- clination of 20%, thus showing that the cores were not water tight and not effective in preventing water from passing through the dam, as the dams were saturated below this plane. While this seepage may be low and have no power to remove any particles of the dam, nevertheless, it is a source of danger and the recommen- dation of the Board to substitute a masonry dam was imme- diately adopted. The puddle core built in the north and south dikes of the Wa- chusett dam consisted of 6-in. layers of fine loam soil, well sprin- kled and rolled. Recent experiments to determine the perme- ability of this type of earth or loam core in an earth dam have been made by means of a series of pipes driven into the embank- ments of the Wachusett dikes. The results as reported indicate that while the plane of saturation on the reservoir side of the loam core was level with the water in the reservoir, it dropped immediately below this core to a level slightly above the base of the dam. Weekly measurements proved that the amount of water draining out of the dike was not in excess of what might be expected, as the natural drainage from precipitation on the area of the dike itself. No masonry or concrete core-wall ever built in an earth dam can show better results than these, and few can compare with them in the absence of percolation from the reservoir. Concrete Core Walls are used in India as protection against burrowing animals only. Puddling clay is scarce and dams are made a homogeneous whole to prevent percolation. For protec- tion from burrowing animals, a G-in. layer of broken stones on the lower slope has been found sufficient in English and Indian dams. The San Leandro Dam. Burr Bassell in Engineering Xews, Sept. 11, 1902, gives the following: The San Leandro dam, of the Oakland Waterworks, Calif., was commenced in 1874, and construction was continued without in- terruption until the latter part of 1875, when a height of 115 ft. above the bed of the creek had been attained. A general plan and a cross-section of the dam are shown in Fig. 1. The crest of the dam is now 500 ft. long and 28 ft. wide. The original width of the ravine at the base was 06 ft. The length of the axis of the base from toe to toe of slopes is now 1,700 ft. The toe of the lower slope is 121 ft. below the high DESIGN AND CONSTRUCTION OF EARTH DAMS 1153 water surface of the reservoir. A puddle-filled trench was car- ried down 30 ft. beneath the original surface, reaching rock, except at the east end, where 20 to 30 ft. of solid clay was pene- trated. It was the original intention of the company to raise the dam 10 ft. every 4 or 5 years until it was 50 ft. higher than it is today, or to a height of 175 ft. above the bed of the creek, and in order to do this safely, the base of the dam was extended to the dimensions shown by the sketches. All that portion of the dam within a slope of 1 on 2 l / 2 at the rear and 1 on 3 at the face, Fig. 1. Plan. Plan and Cross Section of the San Leandro Earth Dam. is built of choice material, carefully selected and put in with great care. The portion outside of the 1 on 2 l / 2 slope-line at the downstream side of the dam, was sluiced in from the adjacent hills regardless of its character, and is of ordinary soil with more or less rock. This process of sluicing was to be carried on during the winter months, by gravity flow, when there was an abundance of water, until eventually it would fill the canyon below the dam. This would give an average slope of 1 on 6.7 at the rear. It was thought that the location was particularly favorable for this kind of construction, the original intention being to raise the dam from time to time, as already stated, not only to increase the storage as the demand for water increased, but to meet the an- 1154 HANDBOOK OF EARTH EXCAVATION nual loss in capacity caused by the silting up of the reservoir basin. I understand that this deposit has averaged about 1 ft. in depth per annum. Some material was also sluiced in on the front, or wet slope, for the reason stated by Mr. Boardman, as follows: The rocky ridge through which the upper and lower tunnels are driven is of a broken formation, some of it very hard and other portions soft, more or less broken and full of seams, and we dis- covered water percolating through the seams into the tunnels. It was impossible to get at the face of the slope, or find the seams, as the reservoir was full, and had it been empty we could not have found them. The only practical way was to sluice in fine clay on the face of the slope, which, under the action of the water, closed up the seams and stopped the seepage. Under the main body of the dam the surface was stripped of all sediment, sand, gravel and vegetable matter. Choice mate- rial, carefully selected, was then brought in by carts and wagons and evenly distributed over the surface in layers about 1 ft. or less in thickness. This was sprinkled with just enough water to make it pack well, not enough to make it like mud. During construction a band of horses was led by a boy on horseback over the entire work, to compact the materials and as- sist in making the dam one homogeneous mass. No rollers were used on this dam. The central trench was cut 30 ft. below the original creek bed. In the bottom of this trench three secondary trenches, 3 ft. wide by 3 ft. deep, were made and filled with concrete. These concrete walls were carried up 2 ft. above the general floor of the trench to break the continuity of its surface. The Ashokan Reservoir. Engineering and Contracting Oct. 19, 1910, gives the following: The Ashokan Reservoir is formed by a masonry dam with earth wings across Esopus Creek, and a long earth dike across the val- ley of the Beaver Kill, in the Catskill Mts., N. Y. The extent of these dams is shown in Fig. 2. Some of the construction quantities involved were: Earth excavation, cu. yds 2,055,000 Rock excavation, cu. yds 425,000 Earth and rock embankment, cu. yds 7,265,000 Portland cement, bbls 1,100,000 Concrete masonry, cu. yds 882,000 Paving and riprap, cu. yds 105,000 Metal work, tons 914 Clearing, acres 200 Vitrified drain tile. lin. ft 21,500 Crushed stone (not in masonry), cu. yds 11,000 Timber and lumber, bd. ft .j.^,,,,^^,. ., . 950,000 Stream control of the Esopus and Beaver Kill. DESIGN AND CONSTRUCTION OF EARTH DAMS 1165 Each end of Olive Bridge dam terminates in a dike known here as the north and south wings. The other dikes are the east and middle west dikes, as shown in Fig. 2. The entire area of the surface which the dike will cover is first stripped of all surface soil and vegetable matter. A vertical trench is then excavated Fig. 2. Map of Main Dams, Ashokan Reservoir. to rock. A concrete core wall is then built in the trench, the average width of which is about 10 ft. at the bottom and 4 ft. on top. After the forms are removed the space between the con- crete and the original earth is filled with clay and tamped to the E/.6IO. &.609 'top soil grossed /2'topsoi/ >i/ grossed 24"ctoy*y torf* core wall, Cut-omt required Fig. 3. Cross-Section of South Wing, Olive Bridge Dam. original surface of the ground. At this point the embankment proper is started by spreading layers of earth 4 ins. thick on the water side and 6 ins. thick on the dry side of the dike. These layers are then rolled with 12-ton Monarch and Kelley steam rollers. The rollers are of special design, having an unusually 1156 HANDBOOK OF EARTH EXCAVATION high horsepower for their weight. The embankments have slopes of 1 on 2 above water level and 1 on 2 l / 2 below water. These slopes are, however, covered with " Class C " rubble riprap. Above water line the slope is surfaced with top soil and grassed. Material was hauled to the embankments in cars and was Fig. 4. Earth Section, Dividing Weir Dam. spread in layers 1% times as thick as the required layer and was then rolled down. Spreading was done largely by hand and all stones too large for rolling into the layers was picked out and used for " Class C " riprap. The Lahontan Dam. This dam for the Truckee-Carson Irriga- tion Project is founded on an unsatisfactory base. Water-bearing passages of small or moderate capacity are of frequent occurrence Gravel and silt mechanically mixed in equal parts, wetted-* and rolled Jn 4* layers \ r 24* Stone rip~rup'on~-}-"f~** iZ pit-run gravel Seamy and fauHed\$~ red 'sandstone arJma 1 } ft stone"grading to I * day in right hank )> of river and having\ numerous water \ bearing fissures ) '5' 2O gaffe, ga/v. pipe, slip joints ^Core drill hole^verage diam.3$" Bored and Grouted Fig. 5. Section Through Lahontan Dam. in the bed rock. The treatment of this foundation with grouting from drill holes is described in Engineering News, Apr. 3, 1913. Much study was given to the character of structure which could safely be built on this foundation to withstand a reservoir head of 120 ft. The original proposal of a gravity masonry dam DESIGN AND CONSTRUCTION OF EARTH DAMS 1157 was abandoned, and finally the embankment type with deep cut- off wall was adopted, as illustrated in cross-section in Fig. 5. Dams for the Porto Rico Irrigation Service. These are de- scribed in Engineering and Contracting, Jan. 19, 1910, and June 22, 1910. From these articles Figs. 6 to 8 are taken. Fig. 6. Sections Near Center and End of Patillas Dam. f/C*/7XJ ^m^iii fine and Impervious : ^^#bxfas3 Fig. 7. Earth Dam at Guyama. Off. '#45.0 Fig. 8. Earth Dam at Villaba. The Patillas Dam comprises some 950,000 cu. yds. excavation and fill for dam, spillway, tunnel, etc. The Caute, located near Guyama, requires 196,200 cu. yds. Dams for Miami Valley Flood Protection, Engineering News, Jan. 25, 1917, describes in detail the design of earth dams and 1158 HANDBOOK OF EARTH EXCAVATION their appurtenances which are to be used in protecting the Miami Valley in Ohio against floods. The engineers aimed at ample safety of the structures, and definite knowledge with respect to all conditions of service and operation. This is shown by the adopted dam section, Fig. 9. Construction of an embankment either by roller compacting (in layers) or by hydraulic deposition was decided to meet all requirements, without lining or core wall. A cutoff trench to go down 30 ft. or so, well below the surface layers, will be used. The section adopted is distinctly more ample than that of the latest and strongest existing dams on tight or semi-permeable foundations though, of course, not comparable with the Wa- chusett or Gatun type. It is proportioned for specially wide base. The features are frequent berms, concaved sides and sym- metrical outline; that is, upstream and downstream faces alike Fig. 9. Typical Cross Section of Miami Conservancy Dams (because these are dry dams). Compared with the standard embankments of the Board of Water Supply of New York City, the upper berm is nearer the top and the slopes flatten out more toward the bottom, to a maximum of 4 to 1. Toe protection of broken stone sloped 10 to 1 may be added if found convenient or desirable. The slopes are to be grassed, top soil being placed on the em- bankment for this purpose. Slope drainage (for surface water) is accomplished by paved berm gutters and connecting gutters down the slopes. The chance of deterioration from settlement or any other cause is held to be vanishingly small with gutters, as compared with buried pipes. The cutoff trench is indicated in Fig. 9, although local condi- tions will determine its depth. It is intended mainly to give most intimate connection between the impervious dam core and the subsoil, and thereby prevent seepage along the base. In all cases the dams will be built on ground stripped of top soil. The subsoil contains very little bedded porous material, so far as the borings and test pits revealed; in the process of making wash borings, the pipe lost its water only rarely. Geological indica- tions are that any porous deposits are local; that is, have little horizontal extent. It is also important to recall that underwash- DESIGN AND CONSTRUCTION OF EARTH DAMS 1159 ing of a dam is a slow process, while here the water will never stand behind the dam more than a short time. A Dam Built Partly of Cinders. Harrison Souder, in Proc. Am. Soc. C. E., Vol. XL, describes the Hinckston Run dam, built in 1901 at Johnstown, Pa. Foundation difficulties, which Were treated by injection of grout, are the subject of Mr. Souder's paper. The original Hinckston Run project called for an earth dam, 60 ft. high, to retain some 400,000,000 gals, of water, with a depth of 45 ft. at the breast. The intention was to build a dam with a clay core, but, as an unlimited quantity of cinder from the steel plant was available, it was decided, after the work was started, to use this as backing for the dam, in place of earth, and even- tually to fill the whole valley below with this material, thus ren- dering the structure practically unbreakable. In view of this and the additional expense incurred in making the cut-off tight, before cinder backing was decided I Creek bottom V Puddled clay floor || ggSfa ^\EL 1289 Fig. 10. Maximum Cross-Section, Hinckston Run Dam. the proposed height of the dam was increased to 80 ft., and later to 85 ft., above the original creek level. This gave a total maxi- mum height above the bottom of the core-wall ditch of 112.8 ft., a depth of water at the breast of 73 y 2 ft., and a capacity of 1,100,000,000 gals. The lake thus formed is 1% miles long. The water-shed above the dam is 10.75 sq. miles. The cross-section of the dam as built is shown by Fig. 10. The lower inner slope is 1 on 2^4, with 4 ft. of puddle and 24 ins. of cinder riprap. The slope above the berm is 1 on 1% with puddle lining diminishing to 2 ft. thick at the top. The facing is hand- laid stone paving. The puddle wall is 16 ft. thick at the top of the concrete core-wall, and diminishes to 4 ft. at the top of the dam. Hydraulic-Fill Dam Built of Lava. J. W. fewaren, in Engi- neering Neios, Mar. 29, 1917, gives the following: A coreless earth dam has been built by the Lewiston-Sweet- water Irrigating Co., in western Idaho, where the only available 1160 HANDBOOK OF EARTH EXCAVATION soil was lava ash and weathered lava. In spite of the nature of the material, the maximum seepage is small. The dam at present is 442 ft. wide on the base, 54 ft. high, and 1,550 ft. long. It is designed for an ultimate height of $5 ft. and a crest length of 3,600 ft. Its present storage capacity is 2,466 acre-feet; when completed, its capacity will be 6,682 acre-feet. The upstream face has a slope of 1 on 3, while a slope of 1 on 2 is given the downstream face. At the point selected for the dam the profile of the ground surface is rather uneven; upstream a fill of 9 ft. was necessary to bring the prism to the grade of the axis. A puddle trench, 8 ft. deep and 10 ft. wide, is placed along the axis. Construction began in 1906. The surface of the ground was stripped and scarified. During the spring months a dike along HlahWcrter Mark Van. 20, 1903 ISO 160 140 120 KX> 80 60 40 20 a 20 40 60 80 100 120 140 160 180 200 220 240 260 Feer Fig. 11. Section Through Lewiston-Sweetwater Lava Dam. the upstream toe (A, Fig. 11) was raised about 34 ft. The earth was placed in 6-in. layers by wheeled scrapers, sprinkled, rolled and harrowed. During the summer months a similar dike (B) was built along the downstream toe. The material for this dike was dumped dry from a trestle. So far as possible, all ma- terial composing the dam prism has been taken from borrow pits inside the flooded area, in order to increase storage capacity. Puddle clay for sealing the toe was obtained from a small, deposit near the north end. While the dike along the downstream toe was being built, water for the irrigation season of 1906 was stored behind the upstream dike. During the fall and winter of 1906 and the spring of 1907 the prism (0) between these dikes was filled by a unique com- bination of water settling and dump-cars. Water from the main canal was conducted into the area between the upstream and the downstream dikes. Earth was dumped into this water from cars DESIGN AND CONSTRUCTION OF EARTH DAMS 1161 running on rails laid along the top of the upstream dike, the water in the pond between the dikes settling the earth firmly and at minimum cost. Water was stored and used for the irrigation season of 1907; and no additional work was done on the dam until September, when a second dike (D) was made on the downstream toe, with its base on top of the fill already in place. The material was dumped from cars on a trestle and settled by water from a iy 3 -in. hose. Additional land coming under irrigation, a larger storage was required. Financial conditions were unsettled at this time, and completion of the dam was out of the question. As the cheapest method of securing the desired capacity, a dike (E) was built on the upstream toe, with its base on the fill already in place. This was built by dumping from cars on a track laid along the center of the fill; the earth was moved both ways by scrapers. This work was stopped at El. 1814, providing for a total storage of 2,466 acre-feet, with water level at El. 1810. The inner face of the dam displays the effect of wave action, each day's draw-down showing clearly in a little bench washed out of the fill. As the line of saturation is rather flat and shifts rapidly, the maximum storage is not made until the last snow run-off. The first irrigation period, closely following, draws down the water level well below the saturation line. During high water in the reservoir, careful watch is kept on a line of test pits along the downstream toe of the dike. Drainage at the downstream toe is carefully developed, and no waterlogging of the prism occurs. At high-water period this drainage is 0.033 sec. -ft. After the close of the irrigating season, with the water at the level of the outlet pipe, drainage is only 1 cu. ft. in 29 min., indicating that in spite of unfavorable mate- rials an excellent bond has been made between the dam and the original ground. A Reservoir Embankment with Concrete Slope. This work is described by J. C. Ulrich, Proc. Am. Soc. C. E., Vol. XXXIX, and abstracted in Engineering and Contracting, June 11, 1912. The embankment, which is about 3y 2 miles long, forms about one-third the perimeter of the Prewitt Reservoir in the South Platt River Valley in Colorado. It has a maximum height of 36 ft. for about 100 ft., with a height not exceeding 25 ft. for the greater portion of its length and an average height of 20 ft. See Fig. 12. The material on which the embankment is founded, and of which it is constructed, consists of very fine sand mixed with a small percentage of soil. Before depositing any earth for the embankment proper, the 1162 HANDBOOK OF EARTH EXCAVATION intercepting trench was partly filled with water, in which selected material was deposited in 2-ft. layers. This operation was re- peated three times in the filling of the trench. The water for this purpose was pumped from a series of 16 wells, put .down just outside of the lower toe of the embankment, at intervals of about 1,000 ft. Sufficient water was thus furnished and used to effect, not merely the moistening, but the actual puddling, of the mate- rial deposited in the trench. The purpose of this puddled trench was to break the continuity of any seam which there might be between the soil of the site and the material of the superimposed embankment. It was also de- signed to cut off and intercept the channels of any dog or gopher holes which might be in the material underlying the embank- ment. After the trench had been filled, and the site had been cleared of all vegetable matter and plowed to a depth of 10 ins., the con- struction of the embankment proper was begun. Highest Wate r ?,.... i L r Surface in'Reservoir '>- ^C ^~-- - Fig. 12. Typical Section of Prewitt Reservoir Embankment. The earth was deposited in layers not exceeding 1 ft. in thick- ness. Each layer was then thoroughly wetted, before the deposi- tion of the next, with water pumped from the wells. ' Then it was rolled with a corrugated roller weighing 125 Ibs. per in. of length. This operation w r as repeated successively until the full height of the embankment was reached. The wetting of this material prior to each rolling resulted in the actual wetting of the whole layer, not the mere moistening of the surface. The contractors kept records of their pumping operations, and these disclose the fact that the volume of water pumped into the material exceeded that of the embankment itself; in other words, the volume of water put into the embankment exceeded that of the earth. The water side of the embankment is protected against wave action by a covering of concrete, 4 ins. thick, extending from its foot to within 2 ft. of its top, where it joints an L-shaped vertical parapet wall of reinforced concrete. At the foot of the surface protection, and connected therewith by reinforcing rods of steel, there is a reinforced vertical " toe- DESIGN AND CONSTRUCTION OF EARTH DAMS 1163 wall," extending 5 ft. into the ground below the edge of the latter. The concrete slope is laid in slabs 10 ft. wide. Beneath the slabs and along the joints are reinforced concrete stringers, 6x12 ins. Small Earth Dams for Stock Watering Eeservoirs. Many of these dams have been built by the Chicago and Northwestern Ry. between its terminals and the ranges in Dakota and Wyoming. According to Engineering and Contracting, Sept. 20, 1911, these dams were built of natural prairie soil with teams and scrapers at an average contract price of 15 cts. per cu. yd. Generally they are not over 15 or 16 ft. high, the maximum being 24 ft. The cost per acre-ft. of water impounded ranged from $6.82 for a reservoir holding 186.1 acre-ft. to $72.40 for one holding 9.3 acre-ft. A feature of these dams is a wave fence, built the full length Fig. 13. Cross Section of Earth Dam Showing Wave Fence. of the slope that is reached by water when the reservoir is full, it is intended to prevent wave erosion. See Fig. 13. A typical dam contains 100 acre-ft., has a top length of 260 ft., a maxi- mum height of 14 ft., and costs $2,300. Determining the Percolation Factor. A. M. McPherson re- commends the following method of procedure in a paper in Engineering and Contracting, July 5, 1911: A uniform sample of the material to be used in the construction of the dam should be taken. It should be thoroughly mixed so as to resemble as nearly as possible the material as it would be placed in the dam. This material should then be placed in a tank which has been constructed for the purpose. A tank 4 ft. wide, 4 ft. deep, and 22 ft. long is large enough to give satisfactory results. A miniature dam is then constructed upon the profile which has been tentatively decided upon, say 3-1 on the inside or water face, and 2-1 on the dry face. The earth should be tamped in, moistened slightly, and made as compact as possible. Piec'es of gas pipe with holes bored along their sides and covered with pieces of wire netting, should be sunk at intervals of about 1164 HANDBOOK OF EARTH EXCAVATION a foot, beginning at the axis of the dam and extending on through the dry face. Water is then admitted on the 3-1 side to a level proportionate to the heighth of the dam, and is kept at this mark until water remains at a constant level in the pipes sunk in the lower side of the dam. This will probably cover a period of several weeks. The depth of the water in the pipes is generally determined by means of a measuring rod. Taking the difference in depth of the water in the various pipes and knowing their distance apart, the angle of saturation is easily calculated. The angle of repose is obtained by trying successive slopes to determine how steep a slope the material will stand when subject to water. This test should be supplemented by another. Have the tank full and suddenly let the water out and note the be- havior of the material. Often this will show what was sup- posedly a safe slope is too steep, as slips will occur as the water is being let out of the tank. It is well after these tests have been made to let the material dry out and notice whether it cracks or shrinks badly. If the material in the miniature dam does not answer satisfactorily to all the tests imposed, it should be discarded and some other material tester, or a mixture of the material in question and some other should be tried. Shrinkage of Earth in a Dam. R. M. Hosea in Engineering and Contracting, Apr. 1, 1908, gives the following data on the con- struction of a dam for the Sugar Loaf Reservoir in Colorado: The entire area of the dam site was overgrown with willows and some trees, and in the lowest portion was covered with 1 to 2 ft. of black muck. All of this was moved, giving a firm clay founda- tion for the earth work. The surface was benched and fur- rowed. Borrow pits were laid out on the inside of the reservoir site over a large area and stripped of all vegetable matter, ex- posing the clay sand mixture, containing some boulders, beneath which was a clay sheet four or more ft. thick. The cross sec- tion of the reservoir dike was about 200 ft. on the base, 25 ft. on the top, with a height of about 40 ft. The inner slope was 3 to 1, while the down stream was 2 to 1. The base was made of moist clay and well puddled. Around all pipes and masonry this clay was placed by hand and tamped. The up stream face was made for a thickness of 20 ft. of the best clay obtainable, the center of the dike prism being of se- lected material, while the poorest material was all placed in the down stream face. The dam was carried up in thin layers. The whole was smoothed, sprinkled and rolled with a heavy steam roller. The formation of layers was carefully avoided by de- positing loads irregularly. DESIGN AND CONSTRUCTION OF EARTH DAMS 1165 Elevating graders were tried for a time, but the presence of boulders made their use inadvisable, consequently a small steam shovel was used to load into wagons, the material being de- posited in that manner. There were 95,388 cu. yds. of earth excavated for the dam prism, while the actual cross section of the dam showed 90,200 cu. yds. The dam remained partly completed through one win- ter, which gave the embankment a chance to become compacted. Throughout the entire work it was sprinkled and rolled. These figures show a shrinkage during construction of 5.44%. Mr. Hosea does not state that any tests have been made to show settlement of the dike since the reservoir has been in use. See Chapter I for data on earth shrinkage. The Tabeaud Dam and Its Cost. The Tabeaud Dam is de- scribed by Burr Bassell in Engineering News, July 10, 1902. Mr. Bassell is also author of a book on this dam. The Tabeaud Dam was built in 1900 and 1901 by the Standard Electric Co. of California as part of a hydro-electric development. Fig. 14. Section of Tabeaud Dam. It is located about 3 miles from Jackson in Amador County Cali- fornia. The crest of this dam is 123 ft. above the natural sur- face of the ground at the foot of the lower slope, and 120 ft. above rock vertically beneath the crest. See Fig. 14. The dam has a crest length of 636 ft. and varies from 50 to 100 ft. in length at the base. It is 20 ft. wide at the top and 620 ft. wide at the bottom. The total volume of the structure is 370,350 cu. yds., and its weight is about 665,000 tons. The dam was designed to have a puddle heart-wall for its whole length, 8 ft thick at the top and increasing in thickness towards the bot- tom. A portion of this was built, but it was discontinued after it had reached a height of 24 ft. Foundation Drainage. Most of the dam rests on firm hardpan and the balance on rock. The excavation extended to rock be- neath both the axis of the dam and near the foot of the inner slope where the puddle face wall abutted against the hillsides. Nearly all the bedrock is of slate, with a dip of some 40 up- stream and a strike of 15 with the center line of the dam. About 150 ft. above the center line a quartz vein crosses the valley, on 1166 HANDBOOK OF EARTH EXCAVATION the line F B T. Between this line and the longitudinal axis the rock was satisfactory, but above the quartz vein: fissures and springs were found. To remove this spring water and to intercept seepage beneath the whole length of the dam, a system of bed rock drainage was constructed. Water from the springs is led to a central point in trenches in the bed rock. The bottoms of these trenches were leved with concrete over which was placed an inverted V-flume, Fig. 15. From the central collecting point water is lead through a 2-in. pipe which is covered with an inverted V-flume (angle . Roc* Waler Bearing Open Space *. ? Interior Puddle Trench. Fig. 15. Details of Foundation Drainage. '"Pipe . . iron). This pipe carries it down stream to the beginning of the bed-rock drain. The inverted flumes of angle iron were covered with concrete which in turn was covered with clay puddle. The hill side drains were located approximately parallel with and 8 ft. below the longitudinal axis of the dam, and were carried to Elev. 1,250. The trench ranged in width from 5 to 10 ft. and extended varying distances into the rock, according to the charac- ter of the latter. The stringers and capstones of these drains were carefully selected and laid. All crevices were then filled with spalls and a covering of 1 to 3-in. broken stone from the tunnel dump was put on to a depth of 18 ins. Above the stone the trenches were refilled with choice thoroughly puddled clay. Observations at a small weir at the outlet of the drain indi- cate a quite constant seepage of about 13 gals, per min. The maximum discharge has been 180 gals, per min. during a heavy rainstorm, DESIGN AND CONSTRUCTION OF EARTH DAMS 11 ; 67 Building the Embankment. The material for the dam was all obtained close at hand. The earth was taken from borrow pits within the reservoir basin at the sides of the reservoir and at the ends of the dam. Most of the rock-fill facing came from the tun- nel dump and the balance from quarries in a ravine to the south of the dam. It was hauled in carts and stick-wagons. The company built only 40,000 of the 370,350 cu. yds. of the bulk of the dam. It had a small steam shovel and some cars on the ground, but the extent to which it used these is not stated. The contractor used a larger steam shovel, of 1% cu. yds. capacity, for about a month, but it mixed so much stone with the dirt that the engineer was not satisfied with it. The con- tractor used fresno scrapers to bring the earth from the borrow pits to a loading platform, or trap, consisting of a timber plat- form with a hole about 20 by 40 ins., through which the wagons were filled. With good material, 8 of these scrapers could fill 25 bottom dump wagons per hr., each wagon having a capacity of 3 cu. yds. The average haul for the entire earth work was one-fourth mile. The maximum equipment of the contractor was as follows: One !} yd. steam shovel ; 37 dump wagons ; 1 1 rock wagons and carts; 39 fresno scrapers; 21 wheel scrapers; 8 road and hill side plows; 3 road graders; 3 sprinkling wagons; 2 harrows; 2 rollers (5 and 8 ton); 233 men; 416 horses and mules. The wheel scrapers were not used. The stripped surfaces were wet by means of hose and nozzles before the embankment was started. The earth was dumped in rows, generally parallel with the longitudinal axis of the dam and ranged from the axis toward the slopes. At the ends of the dam a few rows were frequently made parallel to the inter- section of the embankment and the hill side. The best material was placed at the ends and on the up stream half of the dam. The top surface was kept basin-shaped, giving a slope of about 1 on 25 from the sides to the center. The puddle heart-wall was dis- continued at elev. 1,160 and more attention given thereafter to puddle on the inner face. This change from the original plan was made by Mr. Bassell soon after the contractor started work, because of the character of material available, and the excellent results obtained in securing an homogeneous earthen mass, prac- tically impervious. Besides, the central puddle wall would have greatly interfered with the progress of the work and delayed the completion of the dam. The central section of the embankment, however, received more water than other portions which were not strictly puddle, on ac- count of the basin shape and manner of wetting. Any excess of 1168 HANDBOOK OF EARTH EXCAVATION water in this portion would be readily taken care of by the cross- drains. The contract specifications provided that the puddling material should contain about 70% of clay and about 30% of gravel less than 2 ins. in diameter. Rock-pickers and carts followed the dumping wagons, remov- ing all roots and stones which would not pass through a 4-in. ring. The specifications provided that no stone weighing over 5 Ibs. should be allowed in the dam, and that " layers of rocky material must alternate with layers comparatively free from rock." All the waste was dumped outside the slope line, after which the roots were burned. Six-horse road-graders leveled down the rows of dirt and were followed, in turn, by harrows and rollers, with sprinklers in- terspersed, as was found necessary. By properly spacing the dirt loads and rows, layers of any desired thickness could be secured, while the graders made as smooth and uniformly thick a layer as could be asked. If the material was dry, it was sprinkled as soon as the graders had given it a general leveling; otherwise there was no sprinkling until between the harrowing and rolling, and some of the time none was necessary then. The previous layer, however, was always sprinkled before a new one was added, and hose with nozzles were almost constantly employed for wetting down the outer slopes, the stripped hillsides and all points which the wagons could not reach. One of the two rollers weighed 5 tons and had a 60-in. face, giving 166 Ibs. per lin. in.; the other one weighed 8 tons and had a 40-in. face, thus giving 200 Ibs. per in. The rollers were not grooved, but the loaded wagons passing over the layers cut the surface to a greater or less extent. The loaded wagons weighed over 6 tons apiece, or 750 Ibs. per lin. in. of wheel tread. They were made to travel where they would do the most good, particularly near the edge of the inner slope and along the ends of the embankment where it joined the hillside. Generally the rollers were drawn lengthwise of the dam, but they frequently went crosswise at the ends and also round and round a portion of the surface. The contract specifications stipulated that each 100 cu. yds. of material should be rolled 1 hr., or compressed to an equivalent amount and that the compression should be sufficient to prevent quaking when a loaded wagon passed over the area. The specifications provided that for the first 60 ft. the layers should not exceed 6 ins., and above that level 8 ins. in thickness. The average thickness of the finished layers under the contract work was as follows: April, 4 in.; May, 3%; June, 4; July, 4y 2 ; DESIGN AND CONSTRUCTION OF EARTH DAMS 1169 August, 5; September, 6; October, 7; November and December, 8 ins. Tests of the material used in building the dam, made in June and Sept., 1901, showed the following average weights of 1 cu. ft. of material under different conditions: Dust dry soil, 84 Ibs,; fully saturated, 101.7; natural bank, 116.5; delivered from wag- ons, moist and loose, 76.6; loose dirt from dam, shaken down and measure struck, 80; test pits in dam, 133 Ibs. The earth from the test pits in the dam contained 38% of gravel and grit. The natural soil had 19% of moisture; 33% of water had to be added to it for saturation. Tlie voids were 52% of the total. The angle of repose of the moist earth from the bank was 44; of dust dry dirt, 36%; of saturated dirt, 23%. The cuts at the borrow had vertical sides. Cost of a Dam in Utah. An earth dam for the mammoth Reservois in San Pete County, Utah, is described by J. C. Weelon in Engineering Xews, Oct. 15, 1914: The dam is designed to be 125 ft. in height, eventually, and is built of earth on both sides of a concrete core wall. The core has buttresses on both sides opposite each other, starting 20 ft. wide at bed rock and tapering on a batter to zero at the top of the dam, and spaced 20 ft. apart along the wall. The dam is being built only so fast as the irrigation demands of the farming district require; it has been six years under construction; and, is" now at the 67 -ft. level. The present area of the dam covers one- sixth of an acre. The first work on the earth fill was carried to the 15-ft. level by dump wagons, the earth being rolled with a corrugated roller of 8 tons weight, drawn by four horses. The next 25 ft. was carried on by water. A ditch carried water along the brow of the hillside 150 ft. higher than the work. Teams and plows would make furrows straight down the hill slope from the ditch to the work level on the dam. A small quantity of water re- leased from the ditch into the furrow washed the entire furrow v.pon the dam, while the teams v,*ere coming back up the hill to engage another furrow. The fice water was carried off the work in an improvised culvert through a dike at the extreme up- and down-stream faces of the dam, which was carried a few feet higher than the puddled and thus impounded it. This method^ was found objectionable because the heavy and coarser material, weighing 2,100 Ibs. per cu. yd., dry, would repose next to the hill- side, while the very fine clay, weighing 1,500 Ibs. per cu. yd., dry, would carry in suspension to the center of the work. It was found so difficult to extract the water from this fine clay that the sluicing process was abandoned and rock and gravel were thrown 1170 HANDBOOK OF EARTH EXCAVATION into this puddled and bottomless mass from the edges until men and teams could travel over it. The work is being finished by the use of scrapers and wagons. The canon slopes are covered with a soil of clay and fine gravel which is of fine quality for use in the construction of an earth dam. The dam is being built without any modern machinery, except the smallest stream concrete mixer made. A 12-mile dug-way through a precipitous cauon renders the hauling of heavy freight very difficult. The roller was cast in seven sections so that, with the frame, eight loads could be made of it. The earth fill is costing 38 cts. per cu. yd., and the concrete $9.37 per cu. yd. The overhead charges are nominal. Use of Goats for Compacting Puddle. Work on an earth dam at Santa Fe, N. M., on which goats were used for compacting the puddle, is described in Engineering News, Apr. 13, 1893. This dam, 85 ft. high and over 1,000 ft. long, was built across the Rito de Santa Fe. The upper half of the dam site was exca- vated to rock, and the rock washed with water by means of hose. Fig. 16. Cross Section of Dam at Sante Fe, N. M. The general character of the structure is shown by Fig. 16. The triple sheeting inserted in and carried above the concrete trench and heart walls consists of three thicknesses of 1-in. boards, nailed together horizontally. The upper half of the dam is puddled in layers, a herd of 115 goats having been bought expressly for puddling. These goats are in charge of a herder, who keeps them in motion when on the dam, which is stated to be from 12 m. to 1 p. m., and from 5 to 6 p. m. each day. In commenting on this use of goats in a subsequent issue of Engineering News, J. M. Howells, who was on the work, says: " It was subsequently found that as the travel of the goats did not interfere with the teams, it would be more convenient and economical to use a less number of goats and keep them at work all day. As a result of our experience, we find that 115 goats DESIGN AND CONSTRUCTION OF EARTH DAMS 1171 by constant use would do well the puddling for 30 wheel scrapers, averaging about 14 cu. ft. per load on about 500 ft. haul. " The material was first spread while dumping, next leveled in a 3-in. layer by dragging a beam, next sprinkled with a sprinkling wagon, and then puddled by the goats. The puddling was thoroughly done in this way, and the surface left just rough enough for good joint with the next layer. " As goats in this arid region are a dry hillside animal, I feared such a radical change in their habits as keeping their feet muddy all day would bring on foot disease. No lameness had ap- peared among them up to six weeks ago, and I have had no word of any since; it seems likely their hardiness will carry them through. , " When the goats were first put to work they tired easily, and were able to stand it but a part of the day; we learned this was upon account of the scanty range upon which they had fed, having to rely mostly upon browsing the juniper brush. A few days, however, of feed on peas and refuse hay brought back their accustomed good spirits. And, after their day's work was over, they would butt each other around the corral with the enjoy- ment characteristic of this singularly precocious animal." A Mechanical Flock of Goats. In the preceding paragraph the efficiency of the goat as an earth compacting device is praised. Several years ago a contractor engaged in road building in Cali- fornia learned that a sheep's feet can compact loose earth so hard that a pick-pointed plow will loosen it with great difficulty. He had just plowed up a road when several thousand sheep walked over the loosened soil. The compacting action of their hoofs was so effective that he said : " If those sheep had only post- poned their visit a few hours until I had graded the earth, I would have gladly paid their owner - for their work." Then it suddenly occurred to him that although he could not hire sheep, he might invent a flock of them, which he did. He made a roller with projecting lugs, like sheep's feet, and used it for consolidating subgrades of roads and streets. It is probably the most efficient device available for compacting earth in em- bankments. This rolling tamper, or tamping roller, is made by W. A. Gil- lette, South Pasadena, Calif. t It is illustrated in Chapter VI, and its use for reservoir embankments is described later in this chap- ter. Earth Dam Compacted by Irrigation Flooding. Engineering and Contracting, July 18, 1917, describes the construction of an earth dam for Reeves County Irrigation District No. 1 in Texas. The dam contains 180,000 cu. yds. of material which was exca- 1172 HANDBOOK OF EARTH EXCAVATION vated from the bottom of the reservoir by western elevating graders and hauled to place in western dump wagons. In the construction of the dam the somewhat unusual method of compacting the earthwork by irrigating was employed. The distance of the work from the nearest source of water supply made it impracticable to follow the common method of sprinkling by wagons, and large quantities of water being necessary in the work of puddling, as well as for stock and other purposes, it was thought best to provide a constant supply. This was provided by means of a small ditch nearly 3 miles long, diverted high enough to carry water over the top of the completed dam. Fig. 17. Method of Retaining Water in Puddling. In order to cut off a gravel stratum at the dam site a trench averaging 40 ft. wide at the top and from 5 ft. to 15 ft. wide at the bottom, and 10 to 20 ft. deep was excavated to rock or clay foundation. This was filled with water and good earth ma- terial " bulldozed " in from the end. Over this puddled trench the dam, which is 47 ft. high and 2,500 ft. long was built in 3-ft. lifts. Each lift or layer as completed was bordered and cross- bordered where necessary, and flooded with water as shown in Fig. 17. This water was allowed to stand for several days, the in- tention being to permit the moisture to connect with that of the lift next below. On testing out these lifts with a post hole digger after irrigation, it was found that the earth was well compacted, and a very complete impervious settlement obtained quickly. This pocess of settling and compacting the material was continued to the very top of the dam. DESIGN AND CONSTRUCTION OF EARTH DAMS 1173 Elevating Graders on the Stanley Lake Dam. M. E. Witham, in Engineering Record, Dec. 11, 1909, gives cost data on the use of elevating graders and dump wagons on part of the Stanley Lake Dam. This dam is an earth embankment designed to have an ultimate heighth of 141 ft. and a maximum length of 9,140 ft. at the crest. When the construction was first started a dike was placed along the toe of both slopes of the ultimate section. These dikes were 30 ft. high at the lowest point in the valley across which the dam is being built, and were made to a top width of 30 ft. during the working season of 1908. The material for the dikes was excavated by elevating grader machines from borrow pits directly above and below the site of the dam, and was delivered from these machines to place by 1%-yd. dump wagons. The material handled was largely surface soil and clay, under- lain by a thin stratum of sand and gravel that was used to some extent in the dikes. None of the materials had to be blasted, but it was necessary to loosen them with a plow in some cases. The ground between the borrow pits and dikes was level enough to eliminate difficulty in hauling over it. The dikes also were kept in such shape that no snatch teams were necessary to assist in moving the wagons on them. The grading was under way in July, August, September, October and November, 1908, during which time the amount of rainfall was so small that it did not inter- fere materially with the operations. (A slide occurring on this dam in 1916 is described at the end of this chapter.) In computing the cost of labor the wages paid were increased 50 cts. per day per man for board, including Sundays. Feed for the horses and mules used on the machines and wagons was calculated at 82 cts. per head per day, also including Sundays. A mixture of corn, oats and bran, costing $1.80 per 100 Ib. was used, 10 (100-lb.) sacks being required each day to feed 128 horses, or 48 cts. per head. Alfalfa at $11 per ton was used for rough feed, one ton being the average amount necessary to feed 128 head one day, or 27 cts. per head. The standing force which had to be distributed over the entire contract was as follows: 1 Walking Boss at $125 per month, plus board $5.31 1 Foreman at $100, plus board 4.34 1 Foreman at $75, plus board 3.38 1 Timekeeper at $75, plus board. 3.38 1 Blacksmith at $60, plus board 2.81 1 Blacksmith's Helper at $1.75 per day 1.75 2 Coral Men at $45 per man 4.46 1 Water Boy at $1.75 per day 1.75 Total per day $27.18 1174 HANDBOOK OF EARTH EXCAVATION The cost of the 2-horse dump wagons per day was figured as follows: Driver at $1.75; feed for two horses, $1.64 and 25 cents for depreciation, making a total of $3.64. When three horses were used to a wagon this was increased by the cost of feed for one horse to $4.46 per day. The working day was 10 hrs. Three of the elevating grader machines were used while most of the work was in progress, one of them being pulled by a traction engine and the other two by horses. On one of the horse-drawn machines 12 head of stock were used and 14 head on the other. The figures given are for the 12 -horse machine, while the added cost of the 14-horse machine was taken as the expense feeding two more horses, or $1.64 per day. COST OF OPERATING ELEVATING GRADER MACHINES Machine Hauled by Twelve Horses Elevator man at $45 per month, plus board $2.43 Pilot man at $35 per month, plus board 1.85 Plowman at $45 per month and board 2.23 Push man at $30 per month and board 1.65 Dumper at $2 per day 2.00 Feed for 12 head of stock 9.84 Depreciation 1.50 Cost per day of Twelve-Horse Machine $21.34 Machine Hauled by Traction Engine Engineer at $100 per month and board $4.27 Fireman at $60 per month and board 2.74 Pilot at $35 per month and board 1.78 Plowman at $45 per month and board 2.16 Dumper at $2 per day 2.00 Fuel 1% tons at $3 4.50 Hauling water, with two horses 3.44 Hauling coal, half day 1.72 Lubricating oil and depreciation ( 3.50 Cost per day of Traction Engine Machine $26.11 During the month of August the cost with the traction machine was 13.3 cts. per cu. yd.; the cost with the 14-horse machine was 13.5 cts.; and with the 12-horse machine 12.6 cts. Similar data recorded during the month of September gave the cost for the traction-engine machine as 14.1 cts; for the 14-horse machine, 12.4 cts., and for the 12-horse machine, 12.5 cts. During that month practically no time was lost, and the conditions obtained were generally the same as in August. In October the weather was such from the the seventeeth to the twenty-fourth, inclusive, that the machines were not in use. During this month the 14- horse machine was operated at a cost of 12.33 cts. per cu. yd. On the other horse-drawn machine 12 head of stock were used for the first week, then that machine was drawn by the traction for three days, after which the engine was laid up and 14 head of stock used for the time during the balance of the month when condi- DESIGN AND CONSTRUCTION OF EARTH DAMS 1175 tions permitted work to be done. The cost with this machine for October under these conditions was 13.03 cts. per cu. yd. During all of November only two grader machines were oper- ated, each of them being hauled by 14 head of stock. Both ma- chines were used 14 days, work being interrupted for six days at the middle of the month and operations ceasing on Nov. 27. The average haul was somewhat less during this month, but other conditions were about the same as those above given. The cost with one machine was 12.7 cts. per cu. yd., and with the other machine 13.07 cts. per cu. yd. Early in November 850 cu. yds. of material were placed in a small dike by means of Fresno and slip scrapers. The haul in this case averaged about 100 ft. and the materials were much the same as those moved by means of the grading machines and wagons. This work cost only 6 cts. per cu. yd. In comparing the cost of the operation of the different grading machines it should be noted that the traction engine did not work to advantage. The disadvantage of the engine was due princi- pally to two reasons: First, the alkali nature of the surface waters used in the boiler occasioned delays, and trouble on ac- count of foaming and scale. In the second place, moist and slippery ground handicaps the operation of a traction-drawn grader more than those of one drawn by stock. Over the period of this cost analysis several wet days consequently rendered condi- tions rather hard on the engine drawn machine. The actual average working time per hour for the elevating grader machines was about 45 mins. For a haul of 500 ft. seven wagons to a machine were found to give the greatest efficiency. For each 100 ft. of haul it was considered that one wagon should be added. As a general rule one wagon was considered to haul 1*4 cu. yds. as measured in the embankment. It is evident that, interest, administration, camp equipment and similar overhead expenses are not included in the costs. Embankment for an Oil-Storage Reservoir. E. D. Cole, in Engineering and Contracting, Nov. 24, 1915, gives the following: The general dimensions of the reservoir are as follows: In- side diameter, bottom 462 ft., top 528 ft. ; depth 22 ft. ; width of top of embankment, 11 ft.; inside slope 1% to 1; outside slope iy 2 to 1; thickness of concrete lining, bottom 3 ins., top 2% ins. Earthwork. The formation at the site was a light sandy clay, and this was easily handled by the Fresno and wheel scrapers used throughout the work. After the site was cleared of all brush and grass, the foundation under the embankment was thor- oughly plowed and wet down before the fill was started. Water for moistening the material was supplied through a 2-in. pipe 1176 HANDBOOK OF EARTH EXCAVATION line laid around the site, just outside the outer line of slope stakes, with hose connections approximately 100 ft. apart. A 2-in. line was also run to the center of the reservoir to supply water to the portion of the site which could not be reached from the outside line. To avoid being in the way of the scraper teams, this pipe line was laid through one of the three 12-in. outlet pipes that were placed in position under the fill at the beginning of the work. A narrow trench was dug from the inner end of this outlet pipe to the center of the reservoir, and the 2-in. line was laid, in it. This line was lowered from time to time as the work progressed, and was kept far enough below the surface of the excavation to be clear of the plow and scraper teams. Wetting down the excavation material was a help in several ways, as it not only made a more compact bank, but kept the dust down and made the earth ride better in the scrapers. This may seem in- consistent, inasmuch as the work was done during the rainy sea- son, but can be readily understood on taking into consideration the fact that only 6 working days were lost during the winter on account of wet weather. The embankment was built up in thin layers, about 3 ins. thick, laid parallel to the floor of the reservoir, and well compacted. In addition to the tramping of the scraper teams, the fill was compacted by two petrolitic roll- ing tampers (see Chapter VI for illustration) which were driven continually around the top of the embankment. To insure a compact and uniform backing for the concrete lining, on the inner slope below the natural ground surface, the excavation was started 2 ft. (measured normal to the slope) inside the inner line of slope stakes. This necessarily increased the quantity of excavation, and left the embankment short on the inner slope by this quantity. After the completion of the main portion of the embankment, a lining of selected material, 3 ft. thick (measured normal to the slope), was built up against the inner slope, from subgrade (1 ft. below floor grade) to the top of the finished fill. This extra foot of material was put on to insure a compact surface at the grade line of the inner slope, but was afterward removed, as will be described later.- The refill is an important part of the construction because it would cut off any layers of sand or loose material that might be en- countered in that portion of the inner slope which lies below the ground surface. On some previous work it was found necessary to excavate and refill portions of the natural embankment, below the ground surface, after the fill had been completed and trimmed to grade; this work caused considerable delay and added expense. One concrete-lined reservoir in this field partly failed, due to neglect of this part of the work, necessitating heavy expense in DESIGN AND CONSTRUCTION OF EARTH DAMS 117.7 emptying the reservoir, besides the loss of a considerable quantity of oil and the cost of patching the lining. On the first reservoir, in which a refill was put in, the lining of selected material was started with Fresno scrapers, but these were soon abandoned in favor of wheel scrapers, on account of the difficulty in keeping them from sliding over the edge, and also because the wheel scrapers would build up a bench of the required width, and it was impossible to keep within the limits with the Fresnos. Apparently, the wheel scrapers build up a more compact lining. Trimming Slopes. On the completion of the main embankment and the refill, the excess material on the inner slope, which ranged in thickness from 1 ft. at the top to 2 ft. at the bottom, was trimmed off leaving the slope smooth and true to grade. For this work of trimming the slope, a novel and ( the writer be- lieves) original method was used. Grade stakes were set on radial lines, both at the top and inner toe of the slope, approx- imately every 10 ft. around the circumference of the reservoir. Men with mattocks and slope-level boards then dug narrow trenches, 1 ft. wide and true to grade, from the top grade stake to the stake at the toe of the slope. Then 2 by 4-in. timbers, 38 ft. long, each faced with a narrow strip of strap iron, were placed in the bottom of each trench to act as guides for a trimming ma- chine which was used to finish that portion of the slope between the hand-dug trenches. Before using the planer, however, all excess material above the top of the 2 by 4-in. timbers was scraped off the slope with a specially made Mormon or Buck scraper which was dragged up and down the slope, power being furnished by a double-drum hoisting engine at the center of the reservoir. The back-up line from the engine passed through a 12-in. snatch- block supported at the top of the slope on a portable wooden truss designed for that purpose. This wooden truss was anchored against over-turning by two heavy chains fastened to iron stakes driven into the top of the embankment. As each succeeding sec- tion of the slope was finished, the wooden truss was moved along the top of the bank with a team of horses. After the bulk of the material above the top of the 2x4-in. timbers had been removed, a slope-trimming machine, designed and built by Mr. C. O. Zeller and the writer, was substituted for the Mormon scraper and used to plane off the remaining thin layer of earth and bring the slope to grade or flush with the bottom of the guides. Fig. 18 shows the trimming machine, which consists of a rectangular frame 11 ft. long and 6 ft. wide, built up of 6-in. steel channels bolted together and carrying two cutting blades. The cutting blades are of %x!2-in. flat rolled 1178 HANDBOOK OF EARTH 'EXCAVATION steel, and are set at an angle with the frame of 1 to 2i/ 2 . The blades are also set at a slight angle longitudinally with each other, and the cutting edge projects down 2 ins. below the bottom of the frame. The planer is dragged back and forth on the slope until the ends of the frame ride on the top of the guides, and that particular section is shaved off flush with the bottom of the guides, or down to grade. In this way nearly nine-tenths of the slope were finished by machine and at one-half the cost of doing the work by hand. nV- Fig. 18. Slope-Trimming Machine. Concrete-lined reservoirs of this type cost, complete, from 9y 2 to 10 cts. per bbl. of capacity, depending on the location and other governing conditions. This cost may be distributed ap- proximately as follows: Cost of earthwork $0.03 per bbl. of capacity Cost of roof 0.03 per bbl. of capacity Cost of concrete lining 0.04 per bbl. of capacity Rolling Puddle on Reservoir Embankment Slope. Engineering and Contracting, Apr. 10, 1907, gives the following: Fig. 19 shows the method adopted for compacting an 18-in. layer of puddle on the slope of a reservoir embankment. The embank- ment was for a settling basin forming a portion of the water purification works at Columbus, O. These works occupy a rec- tangular tract 500x700 ft. in area and the spoil and the materials for construction were largely handled by two Lidgerwood travel- ing cableways of 760 ft. span. One of these cableways was turned DESIGN AND CONSTRUCTION OF EARTH DAMS 1170 to the novel duty of operating the roller on the embankment slope. The settling basin was lined with 18 ins. of 2 parts gravel and 1 part clay puddle mixed in a Drake continuous mixer. The puddle was deposited in 6-in. layers, each of which was allowed to dry and was thoroughly rolled before the next layer was placed. For rolling the puddle on the bottom of the reservoir a 5-ton grooved roller made by the Kelly-Spring^ eld Co., was used. The embankment slopes were, however, too steep to permit a steam roller being operated and, therefore, use was made for this task of a home-made roller operated by one of the cableways. The roller Fig. 19. Method of Rolling Reservoir Embankment. was made from two 40-in. diameter fly wheels set close end to end on a common shaft and filled inside with concrete. This roller weighed 1,350 Ibs. and was readily operated laterally up and down the slope or longitudinally up the slope. The whole arrangement proved very successful. A roller, weighing 5 tons and drawn by a portable hoisting engine, was used for rolling slopes of reservoirs at Denver, Colo. (Transactions, American Society Civil Engineers, Vol. 27.) This machine is illustrated in Fig. 20. Self-Loading Wagon for Building Reservoir Embankment. Engineering and Contracting, May 31, 1916, gives the following: In building embankment for the Hiland Avenue Reservoir at Pittsburgh, Pa., a novel device described by Emile Low was employed. This " home-made " machine consisted of a large box, supported by two pairs of wheels, and drawn by three horses. This box held about 1 cu. yd. At the front end there was a slat 1180 HANDBOOK OF EARTH EXCAVATION Fig. 20. Roller for Rolling Slopes. DESIGN AND CONSTRUCTION OF EARTH DAMS 1181 *' elevator, operated by cogs and pinions. At the bottom of the elevator there was a scoop-shaped plow. The material was loos- ened by this plow and then forced upon the elevator and carried into the box. When the latter was full, the scoop or plow was raised and the whole machine was hauled to the embankment. The bottom of this box consisted of a number of hinged slats, which, when turned, allowed the material to drop out gradually, forming a layer of about 4 ins. Ths machine proved an ideal one for building the embankment, first on account of the thin and even layers deposited, and, second, on account of the consolidation of the layers by the passage of the heavy loads over it. Not- withstanding this, rolling with the prescribed heavy grooved roller was never omitted, although it seemed at times to be a senseless requirement. Cost of Embankments and Puddle for a Settling Basin. En- gineering and Contracting, June 25, 1913, gives the following relative to a settling basin for the Minneapolis filter plant: For building the embankment a selected clayey material was obtained from two borrow pits in the immediate vicinity and was hauled by means of common dump wagons of 1*4 cu. yds. capacity, or No. 2 wheel scrapers, as the length of haul demanded. This was spread in 6-in. layers, was well sprinkled and rolled by means of a 14-ton steam roller. On the side of the raised embankment of the settling basin next to the water a puddle wall of selected clayey material 4 ft. thick was built. This puddle was placed in horizontal layers from 1 in. to 2 ins. thick. It was well sprinkled with water and tamped with wooden tampers until the whole was of the proper consistency and was then allowed to dry. Embankments and puddle wall were kept as near the same elevation as possible at all times. After placing the puddle wall and the embankments were at or near their proper heights, a layer of crushed limestone 14 ins. thick measured normal to the slope was placed thereon. On top of this, for a part of the slope distance, a 6-in. layer of 1:2:4 concrete was laid in 10-ft. strips with an asphalt joint between them. The remaining portion of the embankments were covered with sandstone paving stones taken from the north basin which were of no further use there. All inside slopes have a slope of 1 : 2, and all outside slopes I to 1%. Labor Cost Data on Settling Basin for 1911. Earth Fill. The earth fill was well sprinkled with water and was rolled in 6-in. layers with a 14-ton steam roller. The average unit cost on 16,212 cu. yds. of fill was 48.5 cts. per cu. yd. The average haul was 1,200 ft. Amount hand-tamped, 1,100 cu. yds. Puddle Wall. Earth hand tamped in iy 2 to 2-in. layers. Water 1182 HANDBOOK OF EARTH EXCAVATION pumped with hand pump. The average unit cost on 836 cu. yds. was 89.2 cts. Laborers were paid $2.25 per day; and teams $4.72 per day. Labor Cost Data on Settling Basin in 1912, Earthwork. Ex- cavation: 321 cu. yds. of earth were excavated from trenches by hand at an average cost of 78.4 cts. per cu. yd. This cost includes the sheeting and staging. Of the 321 cu. yds. excavated, 236 cu. yds. was dry work, shoveled three times, 40 cu. yds. was wet clay handled four times, and 45 cu. yds. was wet clay handled twice, at average costs of 80 cts., $1, and 40 cts. per cu. yd., re- spectively. Backfill: 747 cu. yds. were backfilled by hand and scraper at an average cost of 34.7 cts. per cu. yd. The ground was wet and partly frozen. This figure includes the hauling of 93 cu. yds. 900 ft. Fill: The fill of 10,773 cu. yds. was well sprinkled and rolled in layers of 6 ins. with a 14-ton roller. Average cost, 49.8 cts. per cu. yd. Puddle Wall. The 1,529 cu. yds. of puddle were tamped by hand in 1% to 2-in. layers at an average cost of 75.7 cts. per cu. yd. The water needed was pumped by hand. Laborers were paid $2.40 per day, and teams $5.00 per day. Labor Cost Data on Filters and Filter House in 1912. Earth- work. Excavation: 2,409 cu. yds. of clay was excavated with pick and shovel at average cost of 65.2 cts. per cu. yd. Some of this clay was handled three times. The cost includes a small amount of sheeting. Fill: 6,494 cu. yds. of fill was made at an average cost of 44% cts. per cu. yd. Sandy soil was used and was tamped by hand under pipes. The average haul of material was 800 ft. Earth Dam at Springfield, Mass. Charles R. Gow in Engineer- ing and Contracting, Jan. 18, 1911, gives the following: A dam for the Springfield (Mass.) Waterworks was 740 ft. long at the crest and its maximum height above the natural ground was 35 ft. Its maximum width at ground level was 165 ft. The slopes were carried 1 on 2 and a roadway 16 ft. wide surmounted its top. A cut-off trench was carried to rock for the entire length, in which was built a concrete cut-off wall 3 ft. thick, extending up: ward from the ledge to a little above the natural surface. Sur- rounding this cut-off wall and extending upward through the middle portion of the cross-section is a clay core built with the material secured from the borrow pit. As practically all of the excavated material was to be utilized in fills* either in the earth dam or in grading over and around the completed filters, no satisfactory system of car transportation for the excavated material was deemed available. Two-horse teams hauling bottom-dump wagons were used throughout the work, and the excavated material was deposited without further DESIGN AND-CONSTRUCTION OF EARTH DAMS 1183. rehandling in its final position. The elevation of filter subgrade was 455, while that of the finished dam was 495, necessitating a final maximum uphill haul of 40 ft. Snatching the Wagons Uphill. A short, steep road was se- lected up the side hill at the westerly end of the dam and an 18- in. gage railway track laid in a straight line from the bottom to the top of this road. A hoisting engine was installed at the top of this track and a weighted car, consisting of a small steel tank filled with concrete and mounted on four wheels, was operated up and down the track by this engine with a cable. The top of this car was just high enough to catch the rear axle of the wagons. In operation the teams drove on to and over the track near its Fig. 21. Settling Basin Dam, Springfield, Mass. lower end and headed uphill with the wheels astride the track, the car at this time being at the lower extremity of the railway. The car was then started up the track, catching against the rear axle of the wagon, and practically boosted the load uphill, the horses being only required to keep the pole headed in the proper direction. At the top of th*e track the team swung oft" downhill toward the fill, and the car ran back by gravity to await the next load. The grade of this road was about 18% and its length about 150 ft. The teams could be handled on it at the rate of one per minute. General Excavation. The item of General Excavation included all excavation for the filters, for the aerator and various building foundations, for stripping at the site of the dike, and in general all cases of earth excavation required under the contract in which the depth of the excavation was less than its breadth. The total amount of yardage included under this item was 56,147 cu. yds., of which 45,081 cu. yds. were handled by steam shovel and 11,066 by hand loading. The excavation for the filters was handled for the most part by ;a steam shovel, while all other General Excavation, including a small amount in the filters, was excavated and loaded by hand 1184 HANDBOOK OF EARTH EXCAVATION labor. The cost records were so kept as to only designate be- tween these two methods. Thew Shovel Work. A No. 1 Thew steam shovel with a I 1 /! -yd. dipper was selected for excavating the filter beds because a large part of the work consisted in very light cuts. It worked well on the first two filters, maintaining an output of from 300 to 500 cu. yds. per day. When excavation for the third filter was reached, many large boulders were encountered, and from that point onward their occurrence became general. The work of excavation now became most tedious and expensive. The shovel, although not dsigned for such work, was able to dislodge many of the small boulders of 1 cu. yd. or less, but a large percentage were of such size as to require blasting before the shovel could proceed. The delays inci- dent to meeting - these obstructions frequently reduced the daily average to less than 100 cu. yds. In some places boulders were so thickly grouped in the ground that it was necessary to resort to hand excavation to clear around and remove them. The gravel surrounding the boulders was cemented to such an extent as almost to resemble concrete. Attempts were made to blast the bank ahead of the shovel, but it was impossible to drill into the mate- rial with any degree of success. The ground contained so large a percentage of stone, both large and small, that neither a churn drill nor a steam drill could be put down without its course being deflected. There remained nothing to do but to scratch away the gravel from around the boulders and pry them out with the dipper or otherwise to blast them. Added to the frequent delays from boulders, breakdowns of the shovel due to the excessive strain upon it occurred almost daily. The cost of steam - shovel filter excavation, including that of teaming it to its disposal point was as follows for 45,080 cu. yds. : Delivering and installing shovel $0.011 Foreman supervising excavation 0.037 Shovel operation, labor 0.047 Coal, oil, etc 0.033 Total $0.08 Repairs, labor 0.007 Repairs, materials 0.014 Total $0.021 Depreciation on shovel 0.039 Teaming excavated material 0^215 General expense, 12.9% 0.052 Grand total per cu. yd $0.455 The cost of installing the shovel includes the expense of four sections of oak platform, each section being 12 ft. long by 5 ft. DESIGN AND CONSTRUCTION OF EARTH DAMS 1185 wide and 4 ins. thick. Each section was fitted with lifting rings so that it could be easily handled by the dipper of the shovel and transferred from the rear to front as the shovel moved for- ward. No dumping expense is charged in the teaming item, as all labor of that nature is included in the cost of the embankment. Hand Excavation. Eleven thousand and sixty-six cu. yds. of General Excavation was loaded by hand methods. A small amount of loam stripping over the filter site was done with wheel scrapers. Much of the area to be stripped, however, was of a marshy na- ture, due to the presence of springs at the upper end of the lot. This rendered the soil so soft as to prohibit the working of horses over it. Other parts of the lot were so stony under the surface as continually to stall the scrapers, and the scraper method of excavation was finally abandoned and wagons and shovels substituted therefor. The permanent diversion of the brook required about 1,200 cu. yds. of excavation, which was executed entirely by hand methods. Part of this channel was quite deep and required some staging and rehandling for the bottom part. Excavation for the office and laboratory building, for the reg- ular house and for the aerator were carried to depths of 7, 9 and 7 ft. respectively. The material in this excavation was ce- mented sand and gravel, requiring loosening with picks but with- out the presence of boulders. The removal of all soil covering the area of the dam site and the first 4 ft. in depth of the cut-off wall trench were also han- dled by hand. Excavation for central drains in each filter was also done by hand labor and was exceedingly difficult, being com- posed mostly of small boulders. The following figures give the average cost of the 11,066 cu. yds. of hand work. Foreman $0.037 Picking and shoveling 0.521 Miscellaneous supplies 0.005- Teaming 0.215 Total $0.784 General expense, 12.9% 0.101 Total per cu. yd Trench Excavation. Various pipes and drains in connection with the several parts of the work required 4,759 cu. yds. of trench excavation. Of this account, 653 cu. yds. were in the cut-off trench for the earth dam. In general, all excavations whose depth exceeded their width were classed as trench excavation. The excavation in the cut-off trench of the dam involved special. 1186 HANDBOOK OF EARTH EXCAVATION treatment and was subsequently handled and paid for as a sep- arate proposition. ' The average cut of the many pipe trenches was about 7 ft. and their average width at the bottom was approximately 4% ft. The specifications provided that the measurement for payment should include slopes of 2 vertical to 1 horizontal, regardless of whether more or less was actually removed. The general nature of the material, however, was such as to allow vertical banks in all cases, mostly without boulders. The cost of this compact cemented sand and gravel trench work was as follows for 4,106 cu. yds. : Picking and shoveling, inc. backfilling $0.243 General expense, 12.9% 0.032 Total per cu. yd $0.275 Blasting Borrowed Excavation. This item of the work em- braced the securing and delivery of such material as was required for the fills in excess of that supplied from General Excavation. It was originally expected that Borrowed Excavation would only be necessary in supplying about 16,500 cu. yds. of clayey mate- rial for the core or middle portion of the earth dam. It subse- quently became necessary to increase the amount of borrow to 30,000 cu. yds. on account of the deficiency of material caused by the elimination of boulders and large stones from the material brought from General Excavation. Material conforming to the requirements of the specifications for use in the core of the dam was obtained on land belonging to the city, at a distance of approximately 2,500 ft. from the dam in an uphill direction. The haul from this point to the dam was, therefore, downhill to the filter site, from which it was necessary to haul up grade as the dam fill increased. The material was a compact, clayey sand, containing at times a moderate amount of gravel. Its location in a side hill af- forded an excellent opportunity for loading, and eventually a face of 50 ft. in height was obtained. An attempt was made to loosen the material by blasting, using black powder in holes drilled some distance back from the face. It was found, however, that water seeping through the material wet the holes, and even when not troubled from water the shots were unsatisfactory, due mainly to the elastic nature of the material. An attempt was then made to loosen a large section of the bank by means of a tunnel driven into the hill and exploding a mine therein. Again the result was unsatisfactory, the effect of the shot manifesting itself in the shape of a small crater while only a comparatively small amount of material was loosened in pro- DESIGN AND CONSTRUCTION OF EARTH DAMS 1187 portion to the amount of labor and explosives required. A suc- cessful method of loosening was finally obtained by the use of undercutting shots. A row of short holes was churned in diag- onally downward along the base of the vertical face of the pit. These holes were fired simultaneously, using dynamite for the purpose. The resulting shot kicked out a triangular strip of the material from under the face, while the shock of the explosion caused the overhanging mass above to crack and topple over, thereby breaking it into a loose pile which was easily shoveled. At times, after the face had reached a considerable height, four or five holes loaded with 10 or 15 sticks of dynamite would loosen and break up from 100 to 150 cu. yds. For loading the material into wagons a large guyed derrick was installed and equipped with a 1-yd. orange-peel bucket which delivered into a hopper under which the teams drove and received their loads. This arrangement was very satisfactory while work- ing, but the frequent delays caused by minor breakdowns and repairs rendered it uneconomical. Wagon Hauling. The average length of haul from the pit was about 2,500 ft., or a round trip of 5,000 ft. The greatest number of trips per team, made or required, was 20 in 10 hours. The average for the entire work was about 18. The wagons holding 1% cu. yd. level measure were ordinarily well rounded up when leaving the pit, but the average load, bank measure, was only about 1 cu. yd. The nature of the material rendered it difficult to team over during or immediately after wet weather, and the same was true of the highway over which the teams were obliged to pass. On the other hand, in dry weather, the highway was deep with dust, adding another unpleasant feature. The cost of 19,952 cu. yds. of clay borrowed for the core wall was: Blasting: Labor drilling holes $0.017 Explosives 0.018 ./.'.:..^...... Loading: Foreman, laborers, etc $0.2022 Coal, oil, plant, etc 0.0226 Special tools used 0.0014 Total cost of loading per cu. yd $0.226 Teaming to dam , 0.36 General expense, 12.9% 0.08 Grand total per cu. yd $0.701 Since double teams cost $6 per day, the teaming charge of ).36 gives an average of 17 cu. yds. per team. It may be added 1188 HANDBOOK OF EARTH EXCAVATION that but few teams could stand this work continuously, and fre- quent changes of teams were required to rest the horses. Second Borrow Pit. When the filter excavation was completed it was found that additional material to the extent of several thousand yards would be required to complete the fills. A borrow pit was accordingly designated by the engineer lo- cated near the tunnel portal at the westerly end of the work, an average distance of 1,400 ft. from the dam and 1,00 ft. from the general fill over and around the filters. The general level of the floor of this pit was somewhat higher than that of the fin- ished dam, and at a slight expense a sidehill road was constructed, which permitted a practically level haul to this point. The steam shovel from the filter excavation was installed in this pit and worked under much more favorable conditions than it had met in the filter excavation. The material first encountered was of a compact, rough gravel, but this soon changed to a sandy clay which was used throughout the upper portion of the dam, both for core and outer fill. The cost of gravel and clay excava- tion in this pit and teaming to the fills was as follows for 16,296 cu. yds.: Foreman $0.022 Loading teams 0.084 Coal and oil 0.016 Total cost of loading per cu. yd $0.10 Moving shovel from filters $0.004 Repairs on shovel 0.082 Total $0.086 Teaming to fills 0.21 Constructing roads and bridges 0.012 General expense, 12.9% t . . . 0.055 Grand total per cu. yd $0.485 The cost of loading is somewhat misleading, since it includes the loading by hand of all soil stripping, a total of 2,330 loads out of 13,843 loads taken from the pit. Spreading and polling the Embankment. After the area to be covered by the dam had been grubbed and stripped of soil, and after the cut-off wall was constructed, material from the borrow pit was dumped, spread by hand and tamped on both sides of the wall until its level reached that of the surrounding ground. From the ground level the fill was carried upward as indicated in Fig. 21, material from the filter excavation being dumped and spread on the two outside thirds and that of the clay borrow pit on the middle third. The several layers were so deposited that the clay and gravel lapped each other alternately at their joints, giving a dovetailed bond between the core and the main fill. The DESIGN AND CONSTRUCTION OF EARTH DAMS specifications required that the layers should be carried 4 ins. thickness. This provision, however, was not rigidly insisted upon, the usual thickness being at least 6 ins., and at times even heavier layers were permitted if in the judgment of the engineer the material was of a nature to admit of proper consolidation by rolling.' This feature is a most important factor in reducing cost, and must, therefore, be considered in connection with the cost figures herein given. For a while the spreading was accomplished by means of a No. 2 Climax road machine drawn by two horses. The teams dumped the material in rows and the machine following level the rows to the required thickness. When the rough material was encountered in the filter excavation, it became impracticable to use the grader, as the large stones were so numerous that the machine was unable to spread the piles even when drawn by four horses. This necessi- tated recourse to hand-leveling and the use of a stone drag and teams to remove stones larger than 6 ins. in diameter which the specifications directed should be excluded from the fill. Small stones from 6 to 12 ins. in size were thrown down the slopes, those on the upstream side remaining there and constituting part of the 3-ft. rock fill called for on that slope, while stones thrown out on the downstream slope were collected and- teamed to the crusher to be broken for use in concrete. All large stones were loaded on a drag and rolled into the rock fill. The specifications provided for the rolling of the embankment with a grooved roller weighing not less than 1% tons per linear foot of roll. This provision, of course, necessitated the use of a power roller. For a short time a traction engine weighing about 10 tons was used for the purpose and gave excellent results so far as the quality of rolling was concerned. It was out of com- mission so often, however, due to breakdowns and defects, that a new Buffalo-Pitts tandem type of steam roller was purchased and its two rolls equipped with heavy steel bands to give them the grooved effect. This roller was rated by the makers at 8 tons, but with its boiler and tank filled and the added weight of the steel bands it actually weighed 12 tons. This total weight of the roller produced the necessary load specified by the specifi- cations on each of its two rolls, consequently every layer received two rollings every time the roller passed, each conforming to the specified requirements. While awaiting the arrival of this roller, a horse roller weigh- ing 2y 2 tons, or y s ton to the linear foot of roll, was used and was drawn by four horses. This roller did not, of course, meet the contract requirements, but a temporary concession was made in the matter by the engineer during this interval. This same horse roller was later used near the top of the dam during a short 1190 HANDBOOK OF EARTH EXCAVATION interval while the steam roller was undergoing repairs. It is estimated that from 8,000 to 10,000 cu. yds., or about 17%, of this embankment was rolled with this horse roller. Considerable difficulty was encountered in rolling the clay core after a rainstorm, with the heavy roller. This material when once wet retained the moisture for a long period, and when sat- urated assumed a jelly-like consistency. On such occasions, lay- ers of gravelly material were spread over it and rolled until the clay squeezed up through it. Sometimes several layers of gravel were required to stiffen the clayey material sufficiently. As a general thing, the teams passed over the dam longitudi- nally with their loads, and it is highly probable that the grooving action of the wheels, together with the tamping action of the horses' hoofs, was of great assistance in consolidating the fill. Very little watering was required, as the material from the filter excavation was usually moist if not wet, and it was found diffi- cult to wet the clay without softening it too much. Material was measured in excavation and embankment and 11,000 cu. yds. of shrinkage discovered. Owing to different classes of fill for which excavation was used, it was not possible to say how much of the total shrinkage was due to the compacting of the embankment; however, this was estimated to have been 11%. The cost of building this embankment, after delivering the earth, was as follows for 52,233 cu. yds. in place: Labor and teams used in spreading material and pick- ing stones $0.0435 Labor making roads and bridges 0.001 Miscellaneous supplies 0.0005 Total for spreading in layers $0.0450 Operating steam roller 0.0098 Coal, oil, etc 0.0055 Depreciation and repairs on roller 0.017 Teams on horse roller 0.0076 Total cost of rolling per cu. yd $0.0399 Teams watering 0.0008 Foreman 0.0151 General expense, 12.9% 0.013 Grand total per cu. yd $0.1138 General Fill. The work embraced under this item included the fills around and over the filters, the grading and loaming of the same and all other fills around the grounds which might be made under the direction of the engineer. The loam originally stripped from the filter site was the only earth rehandled under this item, representing perhaps 1,000 cu. yds. The balance of loam necessary to cover the various fills was paid for both as borrow and as general fill. With the exception DESIGN AND CONSTRUCTION OF EARTH DAMS 1191 of the 1,000 cu. yds. of loam mentioned, the expense charged to this item was limited to that of dumping, spreading and grad- ing material hauled from the excavations. The cost of 22,520 cu. yds. of general fill was as follows: Labor dumping, spreading and grading $0.0618 Teams and labor rehandling 1,000 cu. yds. of loam.... 0.0147 General expense, 12.9% 0.01 Total per cu. yd $0.087 Comment on above figures : The total expense of rehandling 1,000 cu. yds. of loam is here divided into the entire yardage of the item. It actually cost about $0.33 per cu. yd. of loam re- handled, the average haul being about 500 ft. each way. Clearing. Complete data on the cost of clearing and grubbing for this project will be found in Gillette's " Clearing and Grub- bing." Steam Shovels and Elevating Graders on the Belle Fonrche Dam. Engineering and Contracting, Oct. 7, 1908, gives the follow- ing unit costs for part of the work on the Belle Fourche Dam that was built under contract. This dam is built across Owl Creek about 10 miles northeast of Belle Fourche, So. Dak. It is 115 ft. high and 6,200 ft. along the top. The contract was let in Nov., 1905. After placing about one- third of the fill, the contractor made an assignment and the work was taken over by the government. Borings and test pits at the dam site show that the material is homogeneous and compact. An analysis of the earth to be used in the dam was made, and from this the location of the borrow pits determined. The material is an adobe clay, very sticky and boggy when saturated, but bakes very hard when dry, and it is hard to plow. There are occasional layers of sand and shale and scattering cobble stones. The clay is readily compacted and is nearly impervious to water. The dam is built in 6-in. layers and all stones larger than 6 ins. in diameter are excluded. Neither a core or puddle wall is used in the embankment or dike. There are 1,580,000 cu. yds. in the finished embankment. Sprinkling. The fact that Owl Creek runs dry in summer made it necessary for the contractor to store water for use in compact- ing the earth. A reservoir was built, at his own expense, at each end of the dam. Into these reservoirs water was pumped from the creek during the rainy period. The rate of evaporation be- ing high, much more water than actually needed for compacting has had to be stored. The sprinkling was done with hose con- nected on the elaborate system of pipes, laid on top of the dam. When there was water in the creek the water was pumped di- 1192 HANDBOOK OF EARTH EXCAVATION rectly into the system of pipes, but when the creek was dry the reserved supply in the reservoirs was used. Any leaks in the pipes caused troublesome bogs, as the adobe clay absorbs water quickly. On the other hand, when dry, it pulverized easily,- thus causing great clouds of dust on windy days. Although the work was not interfered with on account of rain, it had to be suspended during these wind storms, as neither man nor beast could stand the dust. This dust so affects horses and mules employed on the reclama- tion service that many of them get a lung trouble from which they quickly die. The aridity increases the cost of sprinkling. Another condition that affected the cost of the work was that the surface water was so bad for boilers that the contractor was compelled to put down two artesian wells, each 1,430 ft., to supply water for his steam shovels, locomotives, traction engines, rollers, etc. For about four months in the year the work on the earthen dikes had to be shut down, owing to the cold weather, as the material would freeze in the embankment. All trench excavation, excavation for structures, for stripping borrow and gravel pits, and for trimming embankments, were paid for extra. Amount of Work. The costs below include the cost of the ivork done by the contractor during the years 1906 and 1907, a total of 504,000 cu. yds. Two methods were used in this work; one being steam shovels and trains, moving 305,000 cu. yds.; while the other was by elevating graders and wagons, excavating 199,000 cu. yds. In 1906 one steam shovel was used, while in 1907 two shovels were worked. Cost of Outfit. The outfit and the value of it used on the work was as follows: 2 (75-ton) Vulcan steam shovels $22,000 6 (18-ton) Davenport dinkeys, at $3,100 18,600 40 Western 4-yd. dump cars, at $230 9,200 2 Standard Western graders, at $1,200 2,400 4 (32-hp. 21-ton traction engines, at $3,500 14,000 1 (12-ton) Kelly Springfield roller 2,500 4 Miles of track complete 16,000 2 (6-horse) road machines, $225 450 24 (IMryd.) Aurora wagons, $120 2,880 15 Buck scrapers, $17.50 263 Pumps, pipe, camp, miscellaneous tools, etc. (est.).. 11,707 Total plant $100,000 This is the plant that was on the work at the end of 1907, but not much more than half of it was on the work during 1906; hence, if we figure interest, depreciation and repairs at '2 r / f per month, we have $12,000 for 1906 and $24,000 for 1907, or a total of $36,000 for the two years. Steam Shovel Work. The method of carrying on the steam shovel work was as follows: Two 75-ton Vulcan steam shovels equipped with 2y 2 -yd. dippers loaded dirt into 4-yd. Western DESIGN AND CONSTRUCTION OF EARTH DAMS 1103 dump cars. A train of 10 ears were pulled on 3-ft. gage tracks by 18-ton Davenport dinkeys. Two dinkeys pulled the trains for each shovel and an extra dinkey spotted cars. The cars hauled 3.1 cu. yds. place measurement, as determined by 100,000 loads. During 1906, the material was hauled an average distance of 1 mile against a 2% grade, while in 1907 the 1-mile haul was all down grade, the maximum grade being 4%. Spreading. The tracks on the embankments were so arranged that earth was spread 50 ft. each way from the track. The layers were made 6 ins. deep. As the dumping of the whole train of 10 cars at one time would result in the earth blocking the move- ment of the cars, only alternate cars were dumped, and then the train was pulled ahead a train length and the other five cars dumped. As the cars when coupled measured 13 ft., center to center, this meant a pile of earth containing 3.1 cu. yds. every 26 ft. Each pile spread made about 138 sq. ft. of embankment 6 ins. thick. The idea of dumping alternate cars is excellent on embankments of this character, or even in widening railroad em- bankments, as it makes the spreading of the material easier. At first the attempt was made to spread these piles of earth with a Western Embankment Spreader, but the dinkeys were not powerful enough to handle the spreader against the piles of earth. This spreader will spread the earth about 7 ft. from the rail, so, if it had worked successfully, the area it could cover would have been enough to spread out the pile of earth to a thickness of 6 ins. Six-horse road machines were then tried, but they, too, proved a failure when used alone. The reason for this was that the ma- terial when excavated by the steam shovel came out at times in large clods or lumps, and these lumps tossed the machine around as the waves of the sea would toss a small boat. Recourse was then had to buck scrapers to do the preliminary spreading. These pulled by horses spread the earth out roughly for a distance of 50 ft. on each side of the track, the road machine finishing off the layers. Three layers were thus spread before the track was shifted into a new position, 10 ft. from its old place. The sprinkling was done from the system of pipes run over the reservoir dike. The rolling was done by a 32-hp., 21-ton traction engine and a 12-ton Kelly Springfield road roller. The great weight of the engine no doubt was an assistance in compacting, but unless the tread of the driving wheels of the engine were wider than the standard, the area compacted by one trip of the engine could not compare to that of the roller. This would increase the cost of the rolling over using a roller of the same weight. Wages. A 10-hr, day was worked by the contractor, and, owing 1194 HANDBOOK OF EARTH EXCAVATION to the great amount of construction work going on in all parts of the country at that time, the labor was very indifferent. The shovel men and train crews were paid standard wages, while the laborers were paid at the rate of $2.25 to $2.50 per day. Horses were paid for at the rate of $1.15 per day. This cost covers the care and feed of the horse, likewise the interest and depreciation on the animal, and explains why horses are not listed under the head of outfit. Coal cost delivered on the work $10.50 per ton, 40% dynamite by the car load, 12% cts., and black blasting pow- der $1.20 per keg. Cost of Work. The cost of the work, consisting of the total pay rolls, the cost of supplies and estimated interest, depreciation and repairs, was as follows: Labor . . fc $71,163.44 Supplies 22,827.08 Interest, depreciation and repairs (estimated) 30,000.00 Total $123,990.52 This cost includes superintendence, camp expense, general ex- pense, and, in fact, all direct and indirect cost of doing the work. The overhead charges were about 10% of the total cost. This cost is distributed over the unit costs given below. The steam shovels excavated per day an average of 951 cu. yds., which is an excellent record to maintain for so long a period. The cost of supplying the water for engines and sprinkling has been included in the items given and in the unit costs given below, has been properly distributed. The cost per cu. yd. was as follows : Excavation : Labor $0.047 Supplies 0.027 Total excavation 0.074 Hauling: Labor on train $0.037 Labor on track 0.012 Supplies 0.035 Total hauling $0.084 Spreading: Labor $0.118 Rolling: Labor $0.006 Supplies 0.007 Total spreading 0.013 Sprinkling : Labor $0.014 Supplies 0.004 Total sprinkling $0.018 DESIGN AND CONSTRUCTION OF EARTH DAMS 1195 Plant: Interest, depreciation and repairs (estimated) $0.098 Grand total $0.405 Spreading Earth. This is a high cost for earth excavation of this class, even under the adverse conditions under which the work has been done. This cost is among the highest for earthen em- bankments for reservoirs so far built by the Reclamation service. The high price of coal has added to the cost of loading, hauling, and compacting, but a glance at the unit cost shows that the spreading of the earth on the embankment was too costly. One of the high officials of the Reclamation Service stated that the contractors on this work lost money, having been hampered by a shortage of funds and inefficient superintendents. The contract price for the embankment was 28 cts. per cu. yd. so about 12 cts. per cu. yd. was lost on this part of the work. The. spreading cost about 12 cts. It should have been evident to any one that such a cost was ruinous, as this work on reservoir construction seldom costs more than 2 cts. per cu. yd. On the upper Deer Flat embankment, on the Payette-Boise project, an embankment of about 1,000,000 cu. yds. was built with cars and steam shovels and the cost was less than 2 cts. per yd. for spreading. Here the track was moved away from the earth, after the 'cars were dumped, with teams of heavy horses, when road machines did the spreading, two machines spreading about 300 cu. yds. per hour. The track lies flat on the ground, and is well spiked to 6x8 ties. It stands the rough usage very well. The total cost for this spreading work up to 1908 was 1.9 cts. per cu. yd., although in some months the cost had been as low as 1.4 cts. It is true that at the Upper Deer Flat embankment the earth was free from large clods, but even if the clods that hampered the work at Belle Fourche had been broken up by men with sledges or mauls, so as to make it possible for the road machines to do the spreading, the extra cost for breaking the clods would not have amounted to more than a cent or two per cu. yd., and it would have been less than that had they used a spiked disc harrow. Elevating Grader Work and Hauling. Two Western Standard elevating graders were used on the work, propelled either by 16 horses or 21 -ton traction engines. As a rule the engine is the cheaper method. These graders loaded Aurora dump wagons, having a capacity of iy a cu. yds. The load, place measurement, actually carried was 11 cu. yds., as derived from a record of 100,000 loads. Three horses were used on these wagons, 24 wagons being used to serve the two graders, the average haul 1196 HANDBOOK OF EARTH EXCAVATION being about 1,300 ft. The use of three horses to a wagon is to be commended. The extra cost is entirely in the horse, which in this case amounted to $1.15 per day, and the larger load carried with the other expenses of the work fixed, means that the extra cost of the horse is soon paid. With only 2 horses, either the load would not have been as large, the number of trips would have been reduced, or smaller and less loads would have been hauled. As it was, each wagon averaged about 42 trips per day, traveling a distance over the lead of about 10 miles. Considering the distance covered in following the grader and in turning, no doubt the total distance traveled per day would equal 15 miles. The elevating grader, to a great extent, pulverizes the earth as it excavates it, hence in spreading no trouble was experienced with clods or lumps. This allowed the road machine to do the spreading without assistance, which confirms our statement that some form of -clod breaker would have easily solved the problem of disposing of the clods that came from the steam shovel work. The sprinkling and rolling was done as described under steam shovel work. The wages paid for men and horses are given above, also the cost of coal and other supplies. The Cost of Grader Work. The total cost of the elevating grader work was: Labor $41,530.92 Supplies 4,468,24 Interest, depreciation and repairs (estimated) 6,000.00 Total $51,999.12 This includes all costs, direct and indirect. ,The superintend- ence and overhead charges were about 12% of the total. Each grader loaded 556 cu. yds. per day. The road machine spread about 150 cu. yds. per hour. The cost per cu. yd. of the grader work was as follows: Excavating: Labor $0.047 Supplies . 0.012 Total excavating $0.059 Hauling : Labor $0.126 Spreading : Labor $0.016 Rolling : Labor $0.008 Supplies . 0.008 Total rolling , , , . , $0.016 DESIGN AND CONSTRUCTION OF EARTH DAMS 1197 Sprinkling: Labor $0.011 Supplies 0.003 Total sprinkling $0.014 Plant: Interest, depreciation and repairs (estimated) $0.030 Grand total .;....... $0.261 It will be noticed that the spreading in this case cost 1.6 cts. The wagons deposited the loads 9 ft. apart in windrows 7 ft. apart, and the road machine spread it from these piles. This is real spreading, while in the case of the steam shovels the " spread- ing " consisted first of rehandling and then spreading. It is possible to spread earth very evenly with buck or Fresno scrapers, so that no other work on it is necessary. The Cold Springs Earth Dam, Oregon. D. C. Henry in En- gineering and Contracting, May 24, 1911, gives the following: The Cold Spring Dam is part of the works of the Umatilla project of the United States Reclamation Service. The principal dimensions of the dam are: Greatest height above bottom of creek channel, ft 99 Height above valley bottom, ft 88 Width of valley on center line of dam, ft 400 Length of crest of dam, ft 3,800 Top width, ft ' 20 Length of spillway, ft 330 Up-stream slope 3:1 Down-stream slope j. 2:1 Total volume of dam, cu. yds 673,200 Available Material for Dam Construction. There were available within reasonable distance, the following classes of material: ( 1 ) Basaltic rock, hard and sound, readily blasted, and quite suit- able for rip-rap; (2) gravel in deep hillside deposits on the north side of the canyon, % mile below the dam; (3) fine sandy loam, most readily available in any direction, for use in the embank- ment; (4) pure volcanic ash, in occasional strata and in small quantities; (5) indurated clay deposits, principally at the north end of the dam, and limited in area; (6) sand and gravel in deeper strata underlying the surface soil, and to some extent in- durated. The first three were the only materials that could be obtained in large quantities without extensive stripping. After study and experimentation with these materials, gravel was selected. Sta- bility was secured by the use of gravel throughout the entire section of the dam; water tightness by an admixture of fine sub- soil in the upstream portion; and perfect drainage by the use of d gravel in the downstream portion. 1198 HANDBOOK OF EARTH EXCAVATION The cut-off trench across the bottom of the canyon is 2 ft. deep and 30 ft. wide at its connection with bed rock. It reduces in depth and width up the hillsides until it is 6 ft. deep and has a bottom width of 10 ft. at the ends of the dam. To retard the flow along the plane of contact with bed rock a thin cut-oil wall, 7 ft. high, was constructed on the center line of the trench, across the canyon, reducing in height up the side hill. Five addi- tional walls were built on the north hillside where the rock was exposed. Provision was made for drainage by a gravel-filled trench along the entire downstream toe of the dam with tile drain, and a network of additional trenches under the high portion of the dam, consisting of a parallel trench 120 ft. up stream from the water toe, with cross trenches every 100 ft. Method of Construction. The design called for the handling of approximately 490,000 cu. yds. of gravel from the gravel pit in the north canyon side, about y 2 mile below the dam, for the ex- cavation of 191,000 cu. yds. of loam or subsoil, to be obtained mostly from the slopes within the reservoir, and for about 36,000 cu. yds. of rock pitching, to be placed on both slopes. The gravel was excavated with a 70-ton, Model No. 60, Marion steam shovel, with 2% cu. yd. bucket. The rolling stock con- sisted of fifty 4-yd. side-dump cars and five 16-ton American loco- motives running on a 3-ft. gage track of 35-lb. rails. The aver- age distance of gravel haul was 2^4 miles and the maximum grade was 1%%. The gravel in the pit rose to from 30 to 60 ft. above the shovel and was in places overlain with considerable soil, ren- dering it necessary to watch the proportions of soil and gravel as they came on the cars to the dump. The shovel was served by four gravel trains 6f from 9 to 12 cars each, which handled on an average, including moving and delays, about 1,600 cu. yds. per shift of 8 hours, the output per shift occasionally exceeding 2,200 cu. yds. The total rise from the steam shovel to the top of the dumping trestle was 65 ft., and the coal consumption per locomotive, for 1,149 shifts of 8 hours, averaged 2,400 Ibs., coal being obtained from the Kem- merer mines in Wyoming. The gravel was delivered on the dam by dumping from a trestle, 65 ft. high, built across the canyon, with its center line about 60 ft. down stream from and nearly parallel to the center line of the dam. The entire trestle came within the 100% of the gravel section, and the posts were left buried in the gravel, but all brac- ing was removed as the work progressed. The fine subsoil or loam was obtained from various sources as follows : DESIGN AND CONSTRUCTION OF EARTH DAMS 1199 From surface layers overlying the gravel in the gravel pit 100,000 From borrow-pits on the side-hill, up stream from the dam 108,600 From the feed canal and trenches 40,700 From the spillway channel 17,700 Tota cu. yds 267,000 The loam from the gravel pit was handled in the same manner as the gravel. The loam from the borrow pits was handled by wheel scrapers up to distances of 500 ft. (22,300 cu. yds.), and by dump wagons loaded by an orange-peel excavator for greater dis- tances up to 2,000 ft. (86,300 cu. yds.). The loam from other sources was moved by scrapers, only that portion excavated from trenches, etc., being used which was found suitable, the remain- der being wasted. Spreading and Rolling. The loam was delivered first, in its proper proportions, and spread by a road scraper, after which gravel was spread over it, being scraped by Fresno scrapers from the foot of the gravel dump near the trestle. The materials were mixed at first with disk harrows and subsequently with culti- vators, the points of which scraped over and into the top of the previously mixed and rolled layer, after which the material was watered and rolled, producing a final layer of from 4 to 5 ins. compacted into a hard mass which required picking to excavate. Constant watch was kept of the thoroughness of the mixing process by excavating test pits. It was found impossible to secure complete mixing at all times. Unmixed gravel was no- where found, but in some places fine streaks of loam had been left unmixed with gravel, in spite of every effort to avoid it. The gravel in the 100% gravel section was not rolled to a large extent and was not watered. When the gravel dump had reached the height of the trestle, the track was raised by grading up until the full height of the dam was attained. Riprap. The rock for slope pitching was obtained from the rocky basalt bluff on the north side of the canyon, a short dis- tance below the dam. It broke up in fragments from 1 cu. ft. in volume down. A part of it was loaded by an orange-peel exca- vator, but most was handled from wheelbarrows into dump cars. It was hauled by rail, dumped on the slopes from the dump cars and sloped by hand. The total required was 36,000 cu yds. The construction of the auxiliary structures contained no elements of special interest. The work on the installation of the plant was commenced in December, 1906. The first gravel was dumped in May, 1907, and the dam was completed on January 1, 1908. Shrinkage. The design of the dam calls roughly for one-third 1200 HANDBOOK OF EARTH EXCAVATION of the mass 100% gravel, one-third 50% gravel, and the remaining third 67, 75 and 80% gravel. Laboratory tests indicated a shrinkage of about 10% for the various mixtures, and from this it was figured that there would be required 400,000 cu. yds. of gravel and 191,000 cu. yds. of loam, or a total of 681,000 cu. yds., to make the 637,000 cu. yds. of compacted dam. The actual quantity of gravel excavated corresponds closely to the estimate, but the quantity of soil handled was 76,000 cu. yds. in excess of that figured. This large excess must be principally attributed to the difficulty of keeping the soil and gravel apart in the gravel pit, and may be partly due to the occurrence of vol- canic ash or dust in the delivered soil, which may not have as- sisted in swelling the quantities. The proportion of loam in the gravel, where it came unavoidably mixed with gravel from the gravel pit, may have been underestimated, and it is quite probable that much of the gravel, which from all appearances contained no soil, may have held proportions of from ,:> to 10%. While the excess soil has added to the cost, it can hardly be deemed injuri- ous as regards the drainage qualities of the gravel or its stability, and it has also added to its mass weight. Cost. The total cost of the dam, arranged by its principal features, is shown in the following tabulation: Main dam , $364,140 Auxiliary structures: Inlet works 16,140 Outlet Avorks 19,710 Spillway 35,010 $ 70,860 Preliminary engineering: 5,000 Total, 49,000 acre-ft., at $8.98 per acre-ft $440,000 General administration, engineering and supervision, other than preliminary engineering, are included in the above figures. The principal details of the cost of the main dam are as fol- lows: Embankment (yardage on basis of excavation measurement): Material from gravel pit: Gravel, 490,000 cu. yds.; earth, 100,000 cu. yds.; total, 590,000 cu. yds., at $0.385 $227,020 Material from borrow-pits, spillway and trenches: Earth, 86,300 cu. yds., orange-peel excavator, 36.1 cts 31.120 80,700 cu. yds. wheel scraper at 19.4 cts 15,630 Rip-rap From quarry, 32,500 cu. yds. at $1.46 47,480 From trenches, 3,400 cu. yds. (charged to exca\ation). DESIGN AND CONSTRUCTION OF EARTH DAMS 1201 Excavation A terest Earth from trenches, spillway, etc., temporarily or permanently wasted, 34,400 cu. yds. at $0.293 10,060 Hardpan or loose rock, 6,600 cu. yds at $137 9020 Solid rock, 4,000 cu. yds. at $2.84 11,340 Concrete cut-off walls, 327 cu. yds. at $13.79 4,510 Drainage, including all work to July 1, 1910 7,960 Total $364,140 further analysis of the two principal items may be of in- h Embankment: Material from gravel pit, 590,000 cu. yds. Steam-shovel excavation: Rail haul, average distance 2^4 miles, average rise 65 ft. Cts. per cubic yard, measured in excavation: Steam shovel 3.6 Transportation: Railroad operation 5.5 Track maintenance 1.7 Total 7.2 Work on dam: Scraping, spreading and mixing 8.2 Sprinkling . 0.2 Rolling 0.5 Water supply 0.7 Total 9.6 Plant depreciation 10.4 Plant maintenance 0.4 Total 10.8 General supplies 1.8 Camp shops, warehouses 1.2 Cleaning up, transfer of plant 0.6 Engineering, administration and general expenses 3.7 Grand total, cts. per cu. yd 38.5 Embankment: Material from borrow-pits, 86,300 cu. yds. orange-peel exca- vator, wagon haul, 500 to 2,000 ft. Cts. per cubic yard, measured in excavation: Excavation 13.1 Wagon haul 6.9 Sprinkling 0.4 Rolling 0.7 Water supply ' 0.8 Plant depreciation 8.5 Plant maintenance 0.4 Total 8.9 General supplies 1.1 Camp, shoj>s and warehouses 1.2 Cleaning up, transfer of plant 0.5 Engineering, administration and general expenses 2.5 Grand total, cts. per cu. yd 36.1 1202 HANDBOOK OF EARTH EXCAVATION The cost of gravel and earth for the main embankment, based on bank measurement, is higher than the foregoing figures indi- cate, by reason of heavy shrinkage, and is shown as follows: Material from gravel pit, 590,000 cu. yds. at 38.5 cts.. . $227,020 Material from borrow-pits, etc., 167,000 cu. yds. at 28.0 cts. 46,750 Total, 757,000 cu. yds. at 36.2 cts $273,770 Embankment measurement, 637,000 cu. yds. at 43.0 cts. The prices paid for, labor per 8-hr, day and fuel were as fol- lows Common labor $1.60 to $2.40 Teamsters 2.40 to 2.60 Teamsters, with team 4.50 Steam-shovel engine men 6.20 Cranesmen 4.00 Locomotive engine men 3.60 Carpenters $3.60 to 4.00 Coal, per ton, on work ...... 8.63 Construction of the Kachess Lake Dam. Engineering News, May 15, 1913, describes the construction of an earth dam 65 ft. high and 1,400* ft. long, built across the Kachess River in Wash- ington by the United States Reclamation Service. The dam has a top width of 20 ft. The upstream slope is 3 to 1, the down- stream slope 2 to 1. To prevent percolation a wide cut-off trench about 20 ft. deep was excavated parallel with the axis of the dam and from 20 to 60 ft. upstream from the center line. In the bottom of this trench a narrower trench was excavated to a depth of from 35 to 75 ft. below the original ground surface and in it a concrete core-wall, 2 ft. thick, was built, extending up to the original surface of the ground. See Fig. 22. , Cutoff Trench. The wide cutoff trench was excavated with teams and the drag-line excavator. The portion west of dam conduit was done wholly with teams and was pushed to permit the starting of the core-wall trench. The higher portion of the trench, east of the dam conduit, was done by teams. When water was encountered it was left for the excavator. The drag-line excavator deposited the material at the upstream toe of the dam, making an excellent footing for the riprap, also disposing of the material with one handling. Deep Core-Wall Trench. The excavation of the core-wall trench was commenced early in July, 1911, west of the dam conduit. The upper few feet were shoveled into wheelbarrows and wasted. Shafts were excavated ahead of adjacent portions of the trench, then the excavation was carried in horizontal benches about 7 ft. high. One or two men worked on each bench, loading the material into wheelbarrows, wheeling it along the bench to the side of the DESIGN AND CONSTRUCTION OF EARTH DAMS 1203 shaft and dumping it into a vertical chute that carried the mate- rial to a wood bucket of % cu. yd. capacity, heavily ironed and operated from the head frame. When filled, the bucket was hoisted to the head block, where a simple device dumped the muck into a 1%-cu. yd. car, in which it was hauled by one horse to waste dump. A double drum hoist was used which enabled two shafts to be worked by one hoisting engineer. This method allowed a number of men, working at different levels, on plat- forms laid on trench bracing, to work from each shaft. It was intended to carry this trench to bed rock but the entire excavation was in such uniformly good material that it was con- sidered unnecessary to go so deep. The maximum depth reached was near the westerly end which was carried to 75 ft. below the original ground surface. The material stood so well that gen- erally the excavation could be carried about 10 ft. without sheet- ing. As the core-wall was to be only 2 ft. thick, and it was difficult to carry the excavation narrower than 4 ft., the downstream side was carried true to line, so that the sheeting on that side could remain, and also to give room to remove the forms from the upstream side. Material for the embankment was taken from a borrowpit 1,000 ft. from the east end of the dam. A second borrowpit for loose material was opened 2,500 ft. from the east end of the dam. Trestle. It was decided to depend on rolling to consolidate the dam, carrying material from the borrowpit in cars. A trestle 800 ft. long, of which 300 ft. averaged 60 ft. high, was built of sound timber saved from the clearing. Sawed timber was used for caps and stringers to save time of erection. The bents were 20 ft. apart, three posts to a bent. The trestle was located practically on the center line of the dam, with the base of rail at the "pro- posed crest. It was double tracked with 30-lb. steel rails, 24-in. gage. A double track was laid to the borrow pit for tight mate- rial and a single track, with sufficient turnouts, to the borrowpit for loose material. From the west end of trestle a single track was extended about 300 ft. on a road-bed made with teams and beyond this point the material was hauled by teams. Steam Shovel Work. While the trestle was being constructed, the borrowpits prepared and track laid, the cutoff and conduit trenches were backfilled. The hai i work of filling in cramped quarters had been done the previous season. The steam shovel was moved to a 25-ft. bank of fine material just east of the outlet of the small conduit. Temporary tracks were laid and the filling was done by loading iy 2 -cu. yd. cars with steam shovels and hauling them by teams, The trenches contained some water. 1204 HANDBOOK OF EARTH EXCAVATION The material was dumped, then worked into the water and pud- dled. When the fill got sufficiently dry to permit of using teams, the spreading was done with slips and fresnos. About May 1 the trestle was ready for use, the shovel was moved to the borrowpit east of the dam and the construction of the embankment proper commenced. The pit had previously been cleared and some blasting done. The material from this pit was loaded into trains of 15 1%-cu. yd. side-dump cars, hauled by 9-ton steam locomotives. It was dumped from the upstream side of the trestle, falling to the ground below. At first the material fell inside the outer posts, but the addition of a deflecting apron 7 ft. long, covered with sheet iron, caused it to fall just outside the posts. Spreading and Rolling. Spreading was done with fresnos of four-horse size, but usually drawn by three large horses or mules. It was found after the work became systematized that one fresno would distribute about 115 cu. yd. of the tight material in eight hours. The gravel or loose material was loaded by the drag-line excavator into a specially constructed hopper, of 40-cu. yd. ca- pacity, mounted on skids for moving and fitted with two chutes and controlling gates, which enabled two cars to be loaded at a time. It was hauled in trains of twelve cars, dumped from the downstream side of the trestle and spread with four-horse fresnos. One fresno world spread from 150 to 175 cu. yd. of gravel in eight hours, the haul being much shorter than for the tight material and the gravel more easily loaded. On account of the small working space of the embankment, difficulty was at first experienced in spreading the material as fast as it came in, but while the capacity of the machines was never taxed, a system was soon devised whereby it was kept pretty well cleaned up. About ten trains would be dumped in one pile, then another pile of ten train loads would be made, near the first pile, leaving only room for a roadway between, then a third pile adjacent to the second. While the second pile was being made, the first pile would be spread and stones picked from the second pile; then while cars were dumping on the third pile, the stones would be picked from it and the second pile spread. In this way there was no waiting and no confusion, the roller working on the area previously spread. The tight material occupied the upstream two-thirds of the dam ( Fig. 22 ) and the gravel in the downstream third ; it was handled in the same way except that it spread much easier, and the piles did not req ire plowing, which was necessary with t,he tight material, the impact from falling, particularly in the lower levels of the embankment, compacting this material very tightly. The tight material was spread in 8-in. layers and all, stones DESIGN AND CONSTRUCTION OF EARTH DAMS 1205 exceeding 4 in. picked out, loaded into one-horse dump carts, and placed on the upstream slope. A road grader was on the work but the fresnos spread the material so evenly it was not used. The layer was then sprinkled by a 2-in. hose with %-in. nozzle, the amount of water varying greatly and depending on the weather and the material. The tendency at first was to use too much water, which produced a kneading motion in front of the roller. Carefully watching conditions and reducing the amount of water, sprinkling often with a rather fine spray, corrected this condi- tion. The rolling was done with an ordinary IG^-ton traction engine. Extension rims on the driving wheels gave a rear wheel base of 56 in. Assuming that they carried two-thirds of the weight, the pressure per lin. in. was about 400 Ibs. This engine r^/H El.2268.5 Stripping Line ^tvXrrTTr 12" Drain Tile laid rt o/*7c with' o&fi joints t*G N%^ / >. t"--.-. Maximum depth of 3~v' ~~' core wall was El. 2153 Fig. 22. Typical Section of Kachess Lake Dam. seemed about the right weight for the materials and an excellent embankment was obtained. It was found that the compacted layer was slightly less than 6 in. in thickness. Test pits were p;:t down frequently and at predetermined points, in order to have a complete record of the behavior of the material, to determine whether or not the proper amount of water was being used, and, in general, to indicate whether there was anything to be guarded against or improved. No stratification was apparent; the only adverse criticism to be made was that certain layers that had been exposed to rain showed a little too much water. The gravel was spread in a similar manner except that small stones were not so carefully picked out. The rolling was done by a grooved roller drawn by four horses and more water was used than on the upper side. The stones picked out were placed on the downstream slope. The junction of loose and tight material was approximately at the downstream posts of trestle bents. Progress. To place the large amount of material in the short season available, the small area of the dump preventing tbe crowd- 1206 HANDBOOK OF EARTH EXCAVATION ing of the machines, the shovel and embankment work was car- ried in two 8-hr, shifts, but as only half as much material was required from the excavator it only operated one shift. The best run of the shovel was 1,105 cu. yd. and of the excavator 1,000 cu. yd. in eight hours. The embankment was practically all placed in four months. All trestle bracing was taken out as the fill advanced, nothing being left in but the posts. When within 8 ft. of the top, the gravel portion was brought up about 6 ft., one track thrown on it, the balance of the trestle removed and the remainder of embankment completed. The earthwork yardage was: Excavation, 550,000; embank- ment, 182,000; backfill, 32,000. Drainage. A very complete drainage system was provided to lead off harmlessly any water that may find its way into the dam. At the downstream toe is a generous trench from 6 to 10 ft. wide at the bottom, extending the entire length of the dam, backfilled with stone, which filling is also carried some distance up the slope. From 30 to 60 ft. upstream from the toe is a 12-in. tile drain laid with open joints in a trench and surrounded with 2 ft. of small stone; this drain has frequent outlets to the main drain at the toe. Should water succeed in passing through the tight material, it will drop in the gravel portion, which contains practically no clay, and escape through the drains. Constructing an Embankment for Hill View Reservoir, N. Y. The construction of the earth embankment for the Hill View Reservoir, New York City, is described by A. W. Tidd, in Engi- neering News, Sept. 9, 1915. The soil formation was a very dense, glacial drift, containing many stones and boulders but no ledge rock. The material was well graded from a coarse sand down to a very fine rock flour, excellent for a reservoir embank- ment. The sides of steam shovel cuts stood perpendicular for two years without change other than the scaling off caused by the action of frost. The embankment was constructed of carefully selected and thoroughly compacted material, and backed up by the remainder of the excavated material, which equals and in many places ex- ceeds in volume that of the especially treated portion. The em- bankment on the water side was rolled in layers not thicker than 4 in. when compacted, while in outer portion 2-ft. layers were allowed. This outer portion was formed of material unsuitable for the special impervious (4-in.) embankment. The bonding of the base of the embankment with its foundation was done with extreme care. All unsuitable material was exca- vated and removed, and from the finally stripped surface, small boulders and all stumps and large roots were removed. Large firmly embedded boulders were allowed to remain if there was DESIGN AND CONSTRUCTION OF EARTH DAMS 1207 room between them sufficient to operate the 10-ton steam rollers. Trenches were either backfilled by hand-ramming or sloped enough to allow the roller to ride into and across them. Earth was placed around the boulders and rammed until sufficiently mounded to permit the roller to ride up onto them. The stripped surface under the base of the 4-in. embankment was thoroughly scarified, usually with a road plow, to a depth of 3 or 4 ins., and a thin layer of embankment material was deposited and rolled. An excellent bond was thus effected between the original and the fresh material, and this method was used throughout the entire construction of the embankment whenever work was started on an area that had lain untouched for a time. The 4-in. layers were then started, beginning in the lowest part, keeping the top of the embankment practically level. The dumping areas were restricted, irregular in shape, discon- nected, and often obstructed by boulders. As soon as possible, 3-ft.-gage track with 65- to 70-lb. rails were laid on the embank- ment and the material delivered in 4-yd., side-dumping cars, in 10-car trains, hauled by 10 to 15-ton locomotives. The tracks were laid in straight stretches as long as possible; and two par- allel lines were used until the embankment became too narrow to accommodate them. Spreading and Rolling. The trains were dumped in succession along the full length of the track and the material spread and leveled with a spreader-car into a layer about 6 ins. thick. As soon as the spreader-car had finished (usually in four trips) the track was pulled away a certain definite distance, lined up ex- actly parallel to the previous position, and was ready for trains again. The track was pulled into position by a track gang. The amount of the track throw was determined from careful obser- vations taken on the compacted layers, for each layer, when spread, must just connect with the edge of the previously spread layer, and when rolled must be 4 ins. thick. The steamshovel runners became expert in loading the cars to the limit and at the same time with a very uniform volume. It was on that uni- formity of volume that the success of the whole method depended. The system worked admirably. The track throw was in general 14 ft. The spreader-car was not able to spread the full width even when counterweighted, 10 ft. being about its limit, so the remainder was spread with a 4-horse road scraper. A stone gang worked continuously picking out and removing the boulders and stones larger than 3 in., in order to allow the roller to get onto the layer at the earliest possible moment. Here again the steam shovel runners cooperated by avoiding the larger boulders when loading for the 4-in. embankment. Ten-ton rollers with grooved front wheel and cleated side wheels 1208 HANDBOOK OF EARTH EXCAVATION were used. They were run back and forth parallel to the track, moving over the width of the side wheel about 18 ins. each trip, thus making four rollings on each layer. During hot weather the material required sprinkling to insure proper bonding and thor- ough compacting. The watering was done by an ordinary street sprinkling cart drawn by horses, and the water was applied to the roller layer before the new layer was dumped. A sprinkling car was tried, but given up, as it interfered with the regularity of the train movements. Some difficulty was experienced in secur- ing thorough compacting wherever the direction of track shifting was reversed. In such cases it was necessary to place two layers one on top of the other before the track was shifted, and in the rush to take care of the material as fast as it was sent out from the steam shovels, great vigilance was required to insure that the proper amount of rolling was given the under layer. About 30% of the material was brought on in wagons. All spreading and leveling of the wagon dump was done with 4-horse road scrapers, after which it was rolled in the usual manner. No settlement of the 4-in. embankment was ever detected, and from the evidence deduced from concrete structures built upon it and grade stakes given, the settlement must have been extremely slight, if any at all. Dams of Boulder-Filled Wire Baskets. Engineering News- Record, Apr. 12, 1917, gives the following: Hydraulic mining operations are now permitted in Western states only when there is some means of preventing the earth and rocks washed down by the jet from continuing on into the lower reaches of the stream. One way of accomplishing this is to build a dam across the stream just below the point where operations are under way. By this means there is formed a pool that serves the double purpose of providing a settling basin and capacity for storing the debris. The margin of profit in such mining work is low; and where debris is to be retained by artificial pondage, only a dam that can be built at very low cost is feasible. Two dams have been built in California to meet this requirement. They consist of units, or baskets, of poultry netting filled with coarse gravel and rock. These units are 1 x 2 x 8 ft. in size and are placed lengthwise with the stream. They are built in place and are laid in the same way that shingles are placed on a roof, except that they are level instead of sloping. Each unit is made to lap over half of the preceding course. As each course or layer is completed, sufficient backfilling is put in behind on the upstream side to give the structure a top width of 10 ft., in addition to the courses of netted units. The up- DESIGN AND CONSTRUCTION OF EARTH DAMS 1209 stream side of the fill is kept at a slope of 1% to 1, and the down- stream slope ranges from 2 to 1 down to 4 to 1. In making the units, common netting of 14-gage wire in 6-ft. widths is used. A 10-ft. length of this wire is cut from the roll and put in its place on the dam in a form composed of the last completed basket and a 2-in. plank set on edge and held in place by pins. Into the netting are then poured very coarse gravel and rock up to the size of a man's head. When a sufficient quan- tity has been deposited, the top is leveled off with a straight- edge, and the selvage edges of the netting are drawn together by means of a piece of strap iron with a hooked end. The selvage edges are then fastened together with wire, and the ends are folded in and similarly fastened. Construction Costs. On one of the dams of this type constructed for the Omega mine on Scotchman's Creek, California, the crew consisted of six men. Two men handled the netting, and four men shoveled and wheeled the material. This crew laid 20 bas- kets per day, a total of 320 cu. ft. They also placed the back- filling for this number of maskets, which brought up to 56.3 cu. yds. per day the total amount of material handled. At the rate of $3 per day per man the cost of labor and material in the entire dam was 48 cts. per cu. yd. It is to be noticed that this work requires practically no equip- ment, calls for no initial investment in plant, requires no skilled labor, and, aside from inspection by state officials, only such su- pervision as a foreman can give. The only construction material that has to be shipped in is the netting. The material placed in the baskets is the coarsest obtainable. The backfill is made of finer material ; and as the dam increases in height and the upstream face is continually extended, effort is made to use finer and finer material so that the seal will even- tually be complete and the upstream face of the dam as nearly water-tight as possible. The fact that the downstream slope is made of very coarse material permits seepage to escape promptly, and thus internal pressure cannot occur. Another feature peculiar to this type of construction is that the height of the dam need not be prede- termined and the structure can be continued indefinitely so far as the design and material are concerned. Although the downstream face constitutes a cataract form of spillway over which the stream can quite safely be allowed to flow, the plan has been to provide a separate spillway for the dam when no further increase in height is desired. The first dam of this type on the Pacific Coast was begun for the Omega mine in 1913, and has since been raised by slow stages 1210 HANDBOOK OF EARTH EXCAVATION as the needs of the mine required. It had 43 layers and was about 43 ft. high in 1917. This dam is founded upon an old con- crete dam about 50 ft. in height, the cost of enlarging which by adding more concrete was prohibitive. The second dam of the basket type was being built on Nelson Creek in Plumas County and had attained a height of about 26 ft. Temporary Hydraulic Fill Dam Across Colorado Eiver. En- gineering Record, Dec. 25, 1915, gives the following: For not quite a month, from Sept. 20 to Oct. 3, 1915, the en- tire flow of the Colorado River was diverted into the canal sys- tem of the Imperial Valley by a hydraulic fill dam, about 6 miles below Yuma. The unusual features of the work were the deposition of the dam-building material in the running water of the stream, and the fact that the material was obtained locally in a country notorious for the friable and unstable character of its soil a soil commonly likened to sugar in its action when in contact with running water. However, the dam-building mate- rial was not this light alluvium, brought down by the ruddy Col- orado, but heavier deposits pumped from below the present level of the stream bed. Water for the irrigation of the valley, located in Southern Cali- fornia and the northern part of Lower California (Mexican terri- tory) is taken from the Colorado River just above the interna- tional boundary line. This year the flow of the stream fell below the 7,000 average minimum, endangering the supply to the valley. The California Development Company, which owns the main ca- nals in the valley and sells water to the mutual distributing com- panies, in order to save the crops determined to throw a dam across the stream just below its heading, thus diyerting the entire flow into its canal, and wasting such water into the Salton Sea as might be in excess of its needs. For various reasons it was not possible, or at least not advisable, to put a permanent struc- ture across the stream. The river is considered navigable by the War Department, and the cost of a permanent structure was out of the question because of the financial condition of the Cali- fornia Development Company. Furthermore, immediate relief was needed. It, therefore, was a problem of putting in a tem- porary structure, using such materials as were locally available. While there is at the heading a good quarry, furnishing ample rock, previous ruling of the War Department, requiring a rock- filled trestle across the stream to be removed, barred such con- struction from consideration. Furthermore, a dam of that sort would have been costly, for experience in closing breaks in the Colorado has disclosed endless difficulties in building a pile trestle, the current washing the soft alluvium away from the piles with great rapidity. DESIGN AND CONSTRUCTION OF EARTH DAMS 1211 Attention, therefore, was directed to some type of earth fill structure. Dry-earth handling methods were barred, because with them only the light alluvium could be economically secured. This is an unsuitable dam-building material because even the slowest current carries it away. Hydraulic-carriage methods were therefore resorted to, and were feasible only because beneath the present stream bed a considerable amount of heavier materials is to be found. These consist of stones up to 6 in. in maximum size and, principally, of a mixture of clay, alluvium and gravel, which when wet has considerable strength, and comes through a 10-in. dredge discharge pipe in lumps as large as 6 or 8 in. The theory was that these heavier materials discharged along the cen- ter line of the dam would build up a fairly good current-resistive core, the lighter materials being carried off by the separating action of the water to the upstream and downstream toes. Much of this material would be lost, but the larger particles and lumps would not be carried away by low current velocities. For the closure, which it was recognized would be the difficult part of the work, it was planned to make use of brush and sacks of earth. Procedure. With the plan formulated, a 10-in. suction dredge, with a ladder and suction pipe long enough to reach to a depth of 15 ft. below the present stream bed, was put to work Aug. 12, 1915. The river at this point is about 900 ft. wide, and the dam makes an angle of about 10 with a line normal to the stream flow, the trend of the dam being downstream toward the right bank. The dredge in fourteen days carried the dam to an eleva- tion of 12 ins. above water level, extending from the Arizona shore to within 250 ft. of the California shore. As the fill ros"e, light poles were jetted into it and quantities of willow and cot- tonwood brush piled against them to form a fence. There were two such lines, about 30 ft. apart, within which space materials were pumped to raise the crown of the dam rapidly. Three sub- sequent runs across the stream raised the dam to an elevation of 5 ft. above water level. With the type of construction described there resulted a base width of about 150 ft. and a crown of 30 ft., the depth of water being 6 to 7 ft. When the work was started the velocity of the current was from 2 to 3 ft. per second. As the channel cross-section was decreased the velocity naturally increased and at closure was about 6 ft. Since the stream is subject to rapid rises and it was undesir- able to take more than about 5,000 sec. ft. through the Imperial Valley canals, arrangements were made during the construction of the dam to cut it at two places. The ends of the dam, on each side of the point of final closures, were built as abutments, with brush and stick fences strengthened with sacks of earth, the lines being winged back along the toes. The same type of con- 1212 HANDBOOK OF EARTH EXCAVATION struction was used at another point in the dam, thus making it possible by using light blasts to create quickly two 150-ft. chan- nels. Making the Closure. Before beginning the final closure the bottom was carefully lined with about 10,000 sacks filled with heavy material pumped by the dredge. The closure, which was made in a velocity of about 6 ft. per second, and at the very last instant in a depth of water of about 22 ft., was effected with the aid of cotton wood and willow -brush obtained on the river banks. The brush consisted of young trees, 6 to 10 in. in diameter at the butt, and 20 to 30 ft. long. These were piled on a barge moored upstream at the point of closure. Another barge was loaded with earth- filled sacks, while the dredge was in operation with its discharge line at the closure point. Two 1^4-in. steel cables were stretched from the California shore to the end of the dam beyond the closure point. The procedure was to throw the brush into the stream, butts pointing downstream, and so to guide them that the butts would come to rest against the cables. Bundles of brush weighted with sacks were thrown from the barge and, with the current, immediately brought pressure to bear on the brush, quickly bending the poles until at the steel cables they were pointed vertically upward. The strain on them was relieved by turning the discharge of the hydraulic dredge onto them. In this way progress was slowly made across the channel. Closure wa* effected on Sept. 20, when there was a head of about 6 ft. of water against the dam. The structure remained intact from its completion until Oct. 3, when a rise of the stream, telegraphed ahead from Needles, 300 miles up the river, made it advisable to blow up the closure section. This was done by a charge of dynamite, During the time of complete closure the discharge went as low as 2,700 sec. ft., and on most of the days was about 3,500 sec. ft., all of which was needed in the valley. This w,s an exceptionally low stage of the river, particularly for a protracted period, though a minimum of 3,000 sec. ft. had previously been recorded. Yardage and Costs. Yardage measurements of the prism indi- cate that there were 30,000 cu. yds. of material in the dam, though the pumping records, combined with observation of the percentage of material carried, indicated that 40,000 cu. yds. were pumped. The two figures are not inconsistent, because it is known that much of the fine material was washed to the toes and these lost. The costs for the pumping alone were as follows : Labor $578.38 Fuel oil (13,000 gal.) 416.00 Other oil, and supplies 100.00 Total .. $1,094.38 DESIGN AND CONSTRUCTION OF EARTH DAMS 1213 On the basis of 40,000 cu. yds. pumped this would give a cost of 2.7 cts. per yd. The dredge was immediately upstrea'm from the dam side, so that the length of pumping line was in no case greater than 300 ft. For the final closure 450 cords of brush, at 73 cts. a cord; 21,300 sacks, at a total cost of $1,140, and 1,000 ft. of second- hand %-in. and U/4-in. cable, at a cost of $100, were used. No timber or piling was bought, poles and brush being secured on the banks. The total cost of the work was as follows: Earthwork (dredge) $1,100 Brush and poles 333 Sacks , 1,140 Wire 32 Cable and clamps 100 All labor 2,000 Total $4,705 Add 10% for supervision 470 Grand total $5,175 As against this cost should be set the increased revenue of from $700 to $1,200 per day from the sale of the water. Since low flows are to be expected and are likely annually to embarrass the irrigation district, the California Development Company plans to lengthen the ladder on its dredge in order to get deeper than at present. By so doing still heavier material will be secured and will enable a structure stable under even higher velocities than were experienced this summer to be built. It is expected that the present structure will in part be carried out by high water, but that a considerable base will be left a a foundation for a similar structure next year, should that prove necessary. The dredge, of course, has excavated a deep and ex- tensive hole which, it is expected, will be filled with heavy mate- rial brought down in the freshets of the next high-water season. Cost of an Earth Embankment and Gravel Facing. The fol- lowing data, taken from Engineering and Contracting, Aug. 12, 1908, relate to the construction of the WhaleiT earth dike by the U. S. Reclamation Service. This dike is located at the right extremity of the Whalen concrete diversion weir and extends to the bluff of the valley. This dike, together with the concrete diversion weir abutting onto it, furnishes a means of diverting the now of the North Platte river into the Interstate Canal, and will serve that purpose for the Fort Laramie Canal when it is constructed. The dike is about 1,600 ft. in length, 11 ft. wide on top, with an average height of 10 ft. and side slopes of 2y 2 to 1. The embankment contains about 35,000 cu. yds. of earth. The earth for its construction was taken from a borrowpit, the nearer 1214 HANDBOOK OF EARTH EXCAVATION edge of the borrowpit being not less than 100 ft. and the outside edge at 'about 500 ft. The whole embankment is faced with a covering of gravel, the thickness on the top and downstream slope being 1 ft. and that on the upstream slope 2 ft. Practically the entire embankment was covered with gravel, involving the placing of about 6,040 cu. yds. of gravel. The distance from the gravel pit to the south end of the dike was 1,700 ft. on a down grade of approximately 1% from the pit and the total average haul was about 2,620 ft. The free haul under the specification requirements was 500 ft. The earth body of the embankment was placed in layers varying from 6 to 12 ins. in thickness, and these layers spread by hand and thoroughly compacted by the passage of the scrapers and teams over them. The material as excavated shrank about 20% through the compacting to which it was subjected in being placed in the embankment. The gravel facing was loaded with wheel scrapers through a trap into four-horse wagons with slat bottoms, each holding about 21/2 cu. yds. The gravel was dumped from the wagons onto the embankment, and spread on the slopes by means of a Fresno scraper and a hand shovel. Foremen were paid from 35 cts. to 40 cts. an hour; laborers from 22% cts. to 25 cts. an hour. The labor of horses in the earth work has been rated at 10 cts. an hour, and in the gravel work two-horse teams with drivers at from 40 cts. to 45 cts. an hour; three-horse teams with drivers, at from 50 cts. to 55 cts. an hour, and four-horse teams with drivers at from 60 cts. to 65 cts. an hour. The cost of the 35,000 cu. yds. earth body was as follows, per cu. yd. : Labor $0.219 Plant depreciation Oil Superintendence 004 Total $0.234 The cost of the 6,040 cu. yds. of gravel facing was as follows, per cu. yd.: Labor $0.874 Plant depreciation 022 Superintendence 020 Total $0.916 The grand total cost for these two items was as follows: Labor $12,976 Plant depreciation 535 Superintendence 270 Total $13,781 DESIGN AND CONSTRUCTION OF EARTH DAMS 1215 The cost data above given include 30,000 cu. yds. of overhaul amounting to $450, which is not separately considered. Placing Puddle in a Cofferdam by Pumping. William Martin gives the following in Engineering and Contracting, Jan. 6, 1909: In building Davis Island Dam, several years ago, a cofferdam 1,085 ft. long, containing 5,784 cu. yds. of puddle material, was built by pumping the puddle from an island. The cofferdam consisted of two rows of piles, the rows being 15% ft. c. to c. and the piles in each row being 21 ft. c. to c. The piles were 20 ft. long, and were driven 8 ft. Three rows of wale pieces or stringers were bolted to the piles, 12 ft. apart. A aingle line of vertical sheeting plank, driven 2 ft. into the gravel bottom, rested against the wales. The joints of the sheeting were covered with 1 x 6-in. strips to prevent leakage of the puddle. On each side of the sheeting, at the top, was spiked a 2 x 10-in. string piece, to form a bearing upon which a plank deck was laid. The plant, as finally developed, was as follows : Tubular boiler, 36 ins. diam., x 16 ft. long; engine, 10x10 in.; piston pump steam cyl. 12x18 in.; water cyl. 6 l / 3 x 18 in.; centrifugal pump, 3-in. discharge; pipes, etc. The centrifugal pump for pumping the puddle was located on an island 900 ft. from the cofferdam. Beneath the pump was a tank for mixing the puddle, 8 ft. diameter and 4 ft. deep, sunk to a sufficient depth to secure a fall of water from a flume that tapped the river. The piston pump was connected to the delivery pipe by a wye connection, and was used for priming the centrifugal pump, and keeping the sand from packing, and for furnishing water for the steam boiler and for the agitator hose, as hereafter described. The puddle, consisting of loam and sand, was obtained within a radius of 100 ft. from the pump by loosening with a plow and delivering' close to the tank with drag scrapers. It was then shoveled by hand into the tank, a cost that could have been avoided had the scrapers dumped through a trap into the tank. The material was mixed with water in the tank and kept agi- tated by water from a hose in the hands of workmen* to prevent the earth from settling to the bottom. This puddle was taken by the feed pipe of the centrifugal pump and forced through the de- livery pipe to the cofferdam, a distance constantly increasing as the work progressed. The delivery pipe was laid on the bottom of the river, and then rose by an easy ascent to about 1 ft. above the top of the cofferdam. The puddle occasionally became so thick as to clog the delivery pipe. In order to meet this difficulty, the following ingenious plan was devised. On the delivery pipe at the centrifugal pump was placed a pressure gage. Any clogging of the delivery pipe im- 1216 HANDBOOK OF EARTH EXCAVATION mediately caused the pressure to rise, whereupon the engineman slackened the speed of the centrifugal and opened the valve in the wye connection to the piston pump. This admitted a stream of clear water at high pressure from the piston pump and imme- diately cleared the congestion of puddle in the delivery pipe. The check valve in the delivery pipe between the wye connection and the centrifugal pump prevented a back flow into the centrifugal pump. One of the principal difficulties in working the centrifugal pump was the rapid wear of all its parts that came in contact with the sand. The casing, which was originally % in. thick, wore through in 10 days, during which time not 2,500 cu. yds. of puddle were handled. This was replaced with a 1-in. casing which was still in service after the 13 days' use which completed the job. The stuffing box wore rapidly until the following ingenious de- vice was applied: A screw was cut in the chamber in the opposite direction to the motion of the shaft. A pipe was put in back of the packing and connected with the piston pump. Water was forced through this around the shaft, and, being under a greater pressure than the centrifugal pump, prevented the puddle material from getting into the stuffing box. Water thus applied performed a double duty, for it acted as a lubrication and prevented the shaft from heating. At the discharge end of the delivery pipe the puddle material was deposited in the cofferdam and flowed off for a distance of a few hundred feet, depositing in a hard and solid mass. The loam being lighter, remained longer in suspension and settled out on top of the sand. In 23 days there were delivered 5,784 cu. yds. of puddle mate- rial, or 251 cu. yds. per 10-hr, day. Laborers received $1.75 to $2 a day, and mechanics $2.50 to $2.75. The cost was as follows per cu. yd. : Pump ($145) 3.0 Repairs, fittings, etc. ($382) 6.0 Pipe ($364 6.0 Total plant 15.0 Labor 49 Fuel 4 1.0 Total, cts. per cu. yd 65.0 For comparative purposes it is well to add the following costs of filling another section of another cofferdam near by by another method. The other section was 1,165 ft. long, and it cost $5.69 per lin. ft. for puddle in place, or practically $1.10 per cu. yd. of puddle. The method employed consisted in loading the mate- rial by hand into cars, hauling it over a narrow gage track to DESIGN AND CONSTRUCTION OF EARTH DAMS 1217 the river, loading into boats and transporting to the cofferdam, shoveling by hand into place, and compacting with water. Wages were only $1.25 a day for laborers, and $2.25 for mechanics. Embankment for the Yale Bowl. Engineering and Contracting, July 19, 1916, gives the following: The construction of the great amphitheater for athletic games at Yale University involved 300,000 cu. yds. of excavation and 175,000 cu. yds. of embankment. The bowl, therefore, differs from most modern amphitheaters in being essentially an earthwork structure. It is built in a level plain by excavating the center of the field and using . the excavated material to make an em- bankment around the outside, this embankment forming a com- plete oval about the playing field. The seat slabs are placed di- rectly upon the earth, making it a structure which cannot fall down. The surface of the playing field is about 27 ft. below the original surface of the ground, while the top of the embankment is about 27 ft. above the original surface of the ground, the prom- enade around the top being 54 ft. above the playing field. A wall 4 ft. high surrounds the field. Access to the bowl for spectators is provided by 30 tunnels, each 7 ft. wide by 8 ft. high. These extend from the ground level outside to about midway of the seat bank, and aisles lead up and down the slope from the inner ends of the tunnels. Access to the playing field from the outside is given by two tunnels, one 15 ft. wide by 10 ft. high and suited for entrance of vehicles, steam roller, etc., and the other 10 ft. wide by 8 ft. high, and suited only for pedestrians, as it con- tains stairs, being the only tunnel so constructed. Access may also be had to the playing field by a flight of steps at the foot of each aisle. The outside dimensions of the main structure are 933 ft. by 744 and the structure with its approaches covers an area of 25 acres. The loam which covered the site was first taken off and placed in separate piles of black loam and yellow loam. The depth of the black loam averaged about 10 in. and of the yellow loam about 12 in. Both were of a sandy quality, particularly the yellow loam, some of the latter being but little better than the sandy gravel beneath it. Dragline Excavator. The gravel was placed in the embank- ment at first partly by drag and wheel scrapers, but the main dependence for the excavation was placed upon two large dragline excavators operated from 85-ft. towers which moved on elliptical tracks built closely around the outside of the bowl. These tow- ers operated buckets weighing about 4,500 Ibs. and having a ca- pacity of about 2 cu. yds. The buckets were hauled in toward the tower by a single cable attached to a drum of the engine and run out by gravity on the main cable, which was pulled up 1218 HANDBOOK OF EARTH EXCAVATION by block and fall attached to the head of the tower, and held taut until the bucket had run out as far as desired and then slackened. The other end of the main cable was attached to a post which was moved from time to time so that the bucket might dig from the exact spot desired. Theoretically, a post could have been located at the center of any section of the track which was approximately a circular arc, and all of the material within the sector could have been removed by the bucket, but several practi- cal considerations prevented this from being carried out in the main part of the excavation, although toward the end, when the banks were trimmed by dragging special buckets up the interior slope, this came very near to being the actual layout. The maximum output of one of the excavators was about 1,500 cu. yds. running 22 hours, while the largest month's work for the two was about 45,000 cu. yds. Considerable experimenting was necessary before the exact design of bucket was found which would load itself in the bottom of the hole, and would travel up the slope without digging into the bank which had already been built. The proper shape was finally found, and the buckets worked very well with only an occasional accidental digging be- low grade, which usually took place during the night, when the light and supervision were not particularly good. Quite a little difficulty was experienced in digging through the 10 ft. of sandy gravel, which was fairly compact, although the buckets were heavy and equipped with strong teeth. After this was past, however, the digging was very good and the machines worked easily. Most of the excavation outside of the bowl as well as a portion of that inside was made by two Thew rotary steam shovels with %-cu. yd. buckets loading dump wagons. Embankment. The specifications called for the embankment above the tops of the tunnels to be rolled in 6-in. layers, and the method of operation was for the drag buckets to make three piles of material between each pair of tunnels, the piles being tent- shaped and usually about 3 ft. high, 8 ft. wide and as long as the bank width. These piles were figured to contain just enough material to make the 6-in. layer, being the most practical way in which to regulate this depth. As the towers moved along, they were followed up by teams with leveling boards, which leveled off the piles to a fairly uni- form surface, and this was thoroughly wet down by water from lines of hose and holled eight times, each point being gone over four times by a grooved roller and four times by a smooth roller alternately. The rollers weighed about 800 Ib. per lineal foot and as a rule required four horses, although occasionally a very heavy team would be found which could operate one for a few days without assistance. One larger roller, which required six DESIGN AND CONSTRUCTION OF EARTH DAMS horses, was used for a time. Large quantities of water were used. The contract called for 150 gal. per minute, to be run on to the bank night and day. Below the tops of the tunnels, where rolling was not practica- ble, the material was watered very heavily, and after the fill had got above the tops of the tunnels, special efforts were made to make sure that the water hed penetrated to every portion of the embankment by damming off a section at a time and running all of the water into this section, and punching holes in the bank about 8 ft. on centers by means of drills of water jets. In this way the whole embankment received a uniform treatment, which could not have been assured otherwise, for the sand was so porous that the water from a 2-in. hose would disappear into the bank within 5 or 6 ft. from the end of the hose, and with operation by the ordinary water boy, it was impossible to tell whether every portion of the embankment had been thoroughly soaked or not. When the embankment had been carried nearly to its full height, the excess material on the interior slope was dragged up to the top of the bank by heavy timber frames operated by the drag scraper towers in the same manner as a bucket, these frames being about 10 ft. square and heaving heavy iron plates projecting below the front edge, acting much like a leveling board. They could be made to trim just where it was desired by tighten- ing up the main cable so that they could not go below grade at any point, and they did very good work in shaping up the bank. The final trimming was by hand. The outer slope of the embankment was trimmed partly by level- ing boards operated by power and partly by hand, and was then covered with about 10 ins. of loam, into which strips of turf about 8 ft. on centers were embedded, running parallel to the top of the bank, with the idea that they would help to distribute rain water and prevent it from getting together in sufficient volume to do much damage before it struck another line of turf and was spread out again. The outer slope of the embankment is sloped approximately 1 on 2, except around the portals, where it is about 1 on 1%. These steep places were turfed entirely, but the remainder of the slope was seeded with a mixture of 11% lb. of red top, 5 Ib. of Kentucky blue grass and 20 lb. of white clover. This grew rapidly and seemed to be very good mixture for the purpose, the clover springing up quickly and protecting the grass while it was startling. In this region clover generally dies out after two or three years, while the red top is the native grass and will get a good start by that time. During the placing of the loam and turf a torential rainstorm occurred, in which the theory of the strips of turf was thor- 1220 HANDBOOK OF EARTH EXCAVATION oughly tested and found to be correct. Small guilles formed be- tween the strips of turf, being at most an inch deep at the upper end and 3 ins. deep at the lower end and close together, almost as if a very coarse rake had been dragged down the slope from one strip to another. In no instance did the water dip under- neath the turf, and the gullies at the foot of the bank were very little larger than those up near the top. The total amount of dirt washed away was small, and the only repair necessary was going over with a rake to smooth the slope up once more. Design of Hydraulic-Fill Dams. The conditions of solidity and imperviousness required of an earth dam can be obtained with the hydraulic process as readily as with the ordinary method of placing earth by teams or cars in layers and rolling and tamp- ing. With a breast of great height the hydraulic filled dam can be built easier and frequently cheaper if the proper methods are used. Method and cost of hydraulicking are fully covered in Chapter XVIII. The theory upon which dydraulic-fill dams are generally planned is about as follows: That the inner third of the dam should be composed of impervious material, or material which, by drainage and natural settlement, should consolidate into a mass which will become impervious to water, and remain in a moist, semi-plastic condition ; that the outer half of each of the other thirds should be coarse, porous, open material, through which water drainage from the interior, will pass freely; while the inner halves of the outer zones should be a mixture of the coarse and fine, or a semi- porous material, in condition to act as a filter so as to prevent the escape of any of the fine particles from the inner third, but at the same time allow the slow percolation of water through it. Such a variation in sizes of materials is not always obtain- able. Then the engineer must modify his design to meet the con- ditions. Predicaments of this sort have led to the invention of the hydraulic-fill, rock-fill dam. In this kind of dam the down-stream side of the breast is built of rock, and the rest of it is hydraulic- fill. The core wall is generally the dividing line, but not neces- sarily so. Sheets piles are driven along the up-stream end of tiu rock-fill, to prevent the fine particles of earth from escaping from the center of the dam and flowing away through the rock-fill. In depositing the sluiced material in the dam, care is taken that the earth is deposited on the slopes of the breast, thus keep- ing them higher than the center, which allows the water to collect in a pond at that point. This serves several purposes. The weight of water compacts the material as well as permitting the suspended particles to settle to the bottom, thus preventing the wasting of any of the earth excavated. Then, too, the coarse DESIGN AND CONSTRUCTION OF EARTH DAMS 1221 material is deposited on the slopes, while the finer granules are carried into the center, thus making up the plastic core that is so essential. In rock-filled dams it is evident that it is neces- sary to place a flume or pipe on the up-stream slope only, as the lov/er slope is taken care of by the rock. The excess of water is carried from the pond in the center by flumes, or by syphons, or by connecting the waste culvert in the bottom of the breast by a small shaft, which is built up in suc- cessive layers, through the dam, keeping it at such a height as to retain four or five feet of water in the pond. As this water is run off, it can be stored, if necessary, for use a second time. In designing these outlets for the water, when they run through the dam, it must be remembered that the wet material has con- siderable crushing pressure, and ample strength must be given to the culverts. In a number of cases of dam construction these outlets have failed. Cost of Hydraulicking the Lake Francis Dam. This involved rebuilding and enlarging an old dam made with teams, part of the breast of the dam having been washed away. This work is described by James D. Schuyler in Transactions, American So- ciety of Civil Engineers, Vol. LVIII. Throughout the reconstruction work the minimum cost for labor on any one week's work averaged 3.8 cts. per cu. yd., sluiced and deposited in the dam. The average labor cost was about 15 cts. per cu. yd., and the total cost was less than 20 cts. per cu. yd., including all power, materials and plant. In all 18,300 cu. yds. were deposited in the dam. The record of power used in pumping showed that it cost 1 ct. per cu. yd. for power. Electricity was used. From the channel below the spillway 9,150 cu. yds. were excavated with the monitor at a cost of 3% cts. per cu. yd. Hydraulicking the Concully Dam, Washington. An abstract of a paper by D. C. Henry, Trans. Am. Soc. C. E., vol. LXXIV, is given in Engineering and Contracting, May 10, 1911, as fol- lows: The Concully Dam is part of the Okanogan project of the U. S. Reclamation Service. The principal dimensions of the dam are: Greatest height above bottom creek channel, ft 66 Width of valley on center line of dam, ft 815 Length of crest of dam, ft 1,010 Top width, ft 20 Length of spillway, ft 180 Up-stream slope: upper portion 2%:1, lower portion 3:1 Down-stream slope 2:1 Volume of dam, cu. yds 351,500 Matei~ials Available. The following materials were available for dam construction : ( 1 ) Fine sandy loam near the surface, in 1222 HANDBOOK OF EARTH EXCAVATION the valley bottom, principally to be found up stream from the dam; -(2) gravel and sand from the gravel bar to the east of the reservoir, at a distance of from 2,000 to 5,000 ft.; (3) talus material on the west mountain side, just below the dam, consist- ing of sand and silt from the disintegration of the granite rock, mixed with angular rock fragments of sizes from a man's fist to a cubic yard. The latter material was selected as that most suitable for the dam, in connection with the method of construction to be fol- lowed. It was considered desirable to place the core section as near forward in the dam as practicable so as to have it backed by the maximum quantity of more open material. As a result, the cen- tral plane through the core has a downstream inclination. It was expected that no difficulty would result from this position of the core, as it wcfuld be possible to keep the down-stream dumps at a higher elevation than those up stream and thus maintain the central pond at a point well forward toward the reservoir side. The core section connects with the side-hill by cleaning to bedrock and excavating a rock trench in line with the inclined central core plain. A drainage trench was provided at the down- stream toe of the dam, filled with coarse material, hydraulicked in, connecting with the old creek channel below the dam. Construction. Construction was commenced in the summer of 1907, during which year the following work was done : ( 1 ) Building 3 miles of feed-water flume, mostly on steep mountain sides; (2) building a dirt flume, partly on mountain side, partly on trestle; (3) driving and jetting 855 ft. of 6 by 12-in. triple lap, tongued and grooved, sheet-piling, 36 ft. long, ,for a distance of 33 ft. into valley bottom; (4) excavating 395 ft. of 8 by 9-ft. outlet tunnel, partly lined, through the east mountain side, and excavating a vertical shaft; (5) partial excavation of the spill- way gap in the ridge at the west end of the dam. During the season of 1908, 97,000 cu. yds. of material were sluiced from the borrowpits, and the spillway excavation was completed and lined with concrete. At the end of the season, second-stage flume trestles were erected. During the season of 1909, 188,000 cu. yds. of material were sluiced from the borrow- pits, and the permanent gates were installed in the outlet tunnel. During the season of 1910, the remaining 64,000 cu. yds. of ma- terial were sluiced, mostly from the second-stage, and partly from the third-stage flumes. The dam was completed during Au- gust, 1910. The original supply flume had a capacity of 17 sec-ft. At the end of the 1908 season it was decided to increase this capacity DESIGN AND CONSTRUCTION OF EARTH DAMS 1223 to 26 sec-ft. Small storage reservoirs were built above the flume intakes to permit of concentration of the flow during the dry season for two shifts or one shift each day. The large boulders found in the pit had to be broken by blasting, or wasted, to pre- vent them from accumulating in the bottom. For this reason two pits were kept in operation alternately. The feed- water was led down the mountain side through 14-in. No. 16 steel, slip- joint pipes, one line of pipe for each borrow- pit, and was used partly by the giant, which consumed from 1% to 5y 2 sec. -ft., through nozzles changed from 2 to 3% ins. in diameter, as required. The water was supplied under a head of 129 to 169 ft. for the first stage, and from 114 to 140 ft. for the second and third stages. A flow of from 2 to 3 sec.-ft. was de- livered under pressure through a 4-in. pipe at the head of the bor- rowpit dirt flume near its bottom, serving as push-water. The remainder of the available water was used as push-water at the point where the pit flume dropped its load into the main dirt flume. A small quantity of water, however, was allowed to enter the pit at its upper end on a level with the supply flume, in order to cause the fine upper material to slide in from above. A 7xl3-in. screen was used at the head of the pit flume during the 1908 season, to exclude large rock, but its use was discon- tinued after the water supply was increased. The main dirt flume ran along the lower edge of the pits oppo- site the point on the dam equidistant from its ends, and then pro- ceeded on a high trestle from the mountain side to the dam. On reaching the dam, the main flume connected on each side with two lateral flumes near the down-stream toe of the dam, and con- tinued to similar flumes close to the up-stream toe. When the dam was built up to the elevation of the first lateral flumes the main trestle was raised 29 ft., and was connected with a new flume laid along the mountain side, while the new lateral flume trestles were built closer to the center line of the dam. In the final finishing of the dam, a single flume was built on trestle near the center line. The main dirt flume was built with wooden sides slightly in- clined outward, and with a curved bottom of No. 10 mild steel with a 12-in. radius. The width at the top was 2 ft. 9 ins.' and the total depth 2 ft. 3 ins. The velocity of the water ranged from 14 to 18 ft. per sec. It soon became apparent that the angular rocks sliding on the bottom caused serious wear, and when 11,000 cu. yds. had been delivered, many holes had been worn within a strip in the center ins. wide, the steel higher up showing little wear. The flume was then given a flat wooden bottom 16 ins. wide, and lined with No. 1Q mild steel, which stood the wear far better. 1224 HANDBOOK OF EARTH EXCAVATION At the end of the first season, when it was decided to increase the water supply from 15 to 26 sec. -ft., the dirt flume was rebuilt to rectangular shape, with a bottom 30 ins. wide and lined with 14-in. high-carbon steel, and 27-in. sides lined for the lower 6 ins. with No. 10 mild steel. The heavier and harder steel answered the purpose satisfactorily, and lasted through the delivery of 252,000 cu. yds. of material, showing serious wear only at the butt joints. The flumes had 4% grades, except the short borrowpit flumes, which had 8% grades, and the third-stage flumes for the finishing of the dam, which for part of the distance back had a 3% grade. The material was discharged from delivery points at the dam in two rows of cones, forming ridges, the principal ridge being along the down-stream slope. By deflecting screens, gratings, spouts, and other means, the coarsest material was discharged, as far as possible outward, and the finer material inward, to- ward the pond maintained between the two ridges. The surplus water from the pond was drawn off on the reservoir side through flumes near the ends of the dam, which were alternately raised 6 ins. at a time, the pond being maintained at a depth of from 12 to 18 ins. The material settling in the pond consisted of very fine sand and silt, the coarser sand and gravel coming to rest on the slop- ing sides of the pond, and the large rock dropping vertically and sliding down the cone slopes. The pond at first was quite wide, but, as elevation was gained, it narrowed up to such an extent that in spite of skillful handling, the sloping coarse sand layers would at times extend well into the puddle section and some- times clear across it. Such layers were broken up by systematic stirring with paddles, but when this tendency to stratification be- came more marked and could not be satisfactorily prevented or counteracted, it was decided to introduce an artificial core with puddling material from other sources. The surface material in the valley below the dam, consisting of black, loamy sand, was well suited to form a core. This material was hauled in by scrapers on an up-hill road, dumped on a platform and washed into, the dam through an 8-in. pipe. In order to insure against stratification across this core, two wooden diaphragms were built of 2 by 4-in. studding and 1-in. boards, which were first given a vertical position and made to step back in sections, so as to have their center plane correspond, as nearly as possible, with the cen- ter plane of the general core, but which were later built in a slop- ing position. Thus, while the material from the upper borrow- pits was hydraulicked in on the slopes, the core material was washed in through the 8-in. pipe between diaphragms. The ar- tificial core was started at an elevation 14 ft. above the general DESIGN AND CONSTRUCTION OF EARTH DAMS 1225 base of the clam in the late spring of 1909, and was continued about 39 ft. up to the high-water line. It contains in the aggre- gate 11,600 cu. yds. and, owing to the long haul of about 1,000 ft. 011 a 7% up-grade, and also to the necessity of using a large quantity of lumber for diaphragms, its cost was quite high. The coarse rock, as dumped on the outer slopes, was of suffi- cient size to serve as rip-rap, but it did not prove possible to de- posit it to final slopes by the use of water alone, and after hydraulicking was completed, it required a large amount of hand- work to obtain reasonably good slopes. As the quantity of rock found in the borrowpits was larger than had been estimated, the relative quantity of rock on the water slope became sufficient to justify the steepening of this slope from 3 to 1, as had been originally designed, to 2% to 1 i Fig. 23. Cross Section Concully Dam. for the upper 26 ft. of the dam, as shown by the dotted lines in the central section on Fig. 23. The dam was built with a super-elevation of 1 ft. across the valley, equivalent to nearly 2% of its height. In view of the hard pounding and washing which the material received in being dumped, and the prevalence of sand and gravel, this provision may seem excessive. During the progress of construction, however, it was found that as the load came on the base, considerable settle- ment occurred in the trestles, due apparently to a compacting of the line loamy sand in the foundation. The maximum settle- ment, extending over the last 560 days of construction being 3.9 ft. along the old creek bed. In total volume, this settlement amounted to 15,500 cu. yds. and while it may have ceased on the completion of the dam, it was deemed wise to finish to the super- elevation above mentioned. Careful watch was kept for possible evidence of a swelling up of the ground surface beyond the toes of the dam, but none was observed. The swell in volume during the first season was estimated at 12%, but, for the completed work, a lower percentage is computed, as follows: 1226 HANDBOOK OF EARTH EXCAVATION Sluiced from side-hill borrow-pits, cu. yds... 349,455 Loss in waste water, cu. yds 20,000 Remaining in dam, pit measurement, cu. yds 329,455 Volume of dam, cu. yds 339,900 Swell, 3.2% 10,445 The cost of the reservoir was as follows: Clearing reservoir site $7,652 Main Dam: Creek diversion 965 Clearing dam site 936 Trenches 1,862 Sheet-piling 13,982 Hydraulicking, 339,900 cu. yds. at 45.8 cts 155,637 Peddle core, 11,600 cu. yds. at $1.97 22,885 Sloping 8,465 Miscellaneous - 1,382 Total for main dam $208,219 Outlet works 23,114 Spillway 34, 613 Telephone 2,827 Real estate 30,977 General investigation of dam sites' 19,028 Total cost of 13,000 acre-ft. at $24.95 $324,325 The items in the table include all charges for administration, engineering and general expenses. The cost of puddle core in- cludes lumber for diaphragms. The total material in the dam is 351,500 cu. yds., and the combined cost of hydraulicking and puddle core is $178,522, making the average cost, on the basis of bank measurement, 50.8 cts. per cu. yd., including lumber for core and all overhead charges, but exclusive of the cost of sloping. The details of the cost of hyraulicking are shown in the follow- ing table, the prices paid for labor, per 8-hr, day, being: Common labor $2.25 @ 2.50 Pitmen 2.75@3.00 Giant men 3.00 Powder men 3.00 Carpenters 4.00 @ 4.50 Foremen 5.00 Plant: . cts. per cu. yd. Feed supply dams and flumes 5.04 Dirt flumes and trestles, exclusive of flume lining 5.94 Steel lining 4.40 Pipes, giants and hose 1.09 Electric light plant 0.37 Proportionate share of camp buildings 0.33 Superintendence 1.49 Administration, engineering and general expenses 2.29 Total ($71,204) 20.95 Less value of plant on hand 0.62 Total plant 20.33 DESIGN AND CONSTRUCTION OF EARTH DAMS 1227 Supplies : Tools 080 Rubber boots and clothing " Powder and explosives v.v. O'AK Proportionate share of camp buildings J.Wb Superintendence n 'n R Administration, engineering and general expenses 0.36 O AO Total supplies .... Labor: Foremen i' 17 Building road to pit "-M Clearing borrow-pit "" Feed-supply flume tenders j-i* Giant men oeo Pit men 4fi Clearing pit of rock ....... g Building lateral flume m pit & Hauling and laying pipe in pit .._.. ' Dirt flume tenders *** Labor, steel lining *"? Spreading material and puddling in dam W.w Carpenters on dam and flumes , * Blacksmith .27 Operating light plant "* Transporting laborers - "<> Dismantling plant ".;. noa Proportionate charge for camp buildings u.^ Superintendence J-^ Administration, engineering and general expenses ^.Uo Total labor 21.99 Total cost hydraulicking 339,900 cu. yds., cts. per cu. yd 45 - 80 Hydraulicking the Bear Creek Dam. This dam is part of the Jordan River development on Vancouver Island. It was com- pleted in May, 1912, and forms a storage reservoir for an hydro electric plant. C. E. Blee describes the construction of the dam in Engineering and Contracting, May 21, 1913. Some of the dimensions are: Total volume of dam (embankment measurement), cu. yds 148,390 Length of crest of dam, ft :..-. 1,017 Greatest height above original ground surface, ft 57 Greatest height above bottom of sheet piling curtain, ft 127 Top width of dam, ft 15 Upstream slope of dam 3 to 1 Downstream slope of dam ZVz to 1 Capacity of spillway, cu. ft. per sec 5,000 Distance of spillway entrance below crest of dam, ft. 15 Distance of high water level below crest of dam, ft. 5 Cut-Off Trench. As soon as stripping had advanced far enough to permit it, work was started on a cut-o.ff trench, extending throughout the length of the dam and parallel with the axis, the center line of the trench being directly under the downstream edge of the crest of the dam. This trench (Fig. 25) was 6 ft. wide at the bottom, and averaged about 20 ft. deep, with side slopes of 1228 HANDBOOK OF EARTH EXCAVATION % to 1. At both ends of the dam it was carried down to bed- rock as far as the practicable depth of the trench would permit, the bedrock dipping rather rapidly toward the center of the valley. The material excavated consisted of a semi-cemented gravel, and heavy boulders with thin layers of sand at deeper levels. The first lift of 5 or 6 ft. was shoveled directly into wheelbarrows. The greater part of the remainder was removed by a steam derrick with skips, a hand derrick also being used in some extent. The smaller material in the section under the old stream bed, where considerable water was encountered, was removed with a hydraulic elevator. All material excavated from the trench was placed in the em- bankment, excepting near the ends where, due to the narrowness of the base of the dam, but little of this material could be used, and it was more economical to waste it than to haul it to the wider portions. In placing material of any description by means other than sluicing, care was observed to keep it well without the limits of the middle third of the section, in order to re- serve the central portion for the puddle material deposited under water. The material from the trench excavation placed in the embankment was largely used to start the toe of the slopes of the dam, thus forming dikes some 5 ft. or more in height, which would serve to retain the sluicing pond and to be other- wise useful at the time of starting the fill by sluicing methods. The total volume of material removed from the trench was 8,675 cu. yds. The direct labor cost of excavation when a steam derrick was used was approximately $1.00 per cu. yd. Borrowpits. The main borrowpit was located on the north side of the valley, directly opposite the dam and about 400 ft. from the north end of the dam axis. Test pits showed this to be the only available deposit sufficiently large to furnish the material for the embankment. The material was a hard-pan made up of sand, gravel, and boulders, mixed with clay, and overlying the bedrock in depths of from 8 to 18 ft. It was not an economical material to handle, as it was necessary to break it witli powder; it required a heavy grade on the flumes, and a large amount of boulders had to be handled and wasted in the pit; but it was so proportioned that when segregated and deposited by the hydraulic process it formed an embankment which, for sta- bility and imperviousness, could not be surpassed. Small borrow-pits were opened on the south side of the valley to be used in finishing the south end of the dam. The main pit was at an elevation of from 150 to 250 ft. above the valley floor, which is equivalent to 95 and 195 ft. above the crest of the dam. Equipment for Sluicing. A gravity supply of water was ob- DESIGN AND CONSTRUCTION OF EARTH DAMS 1229 tained from a small tributary creek rising on the north slope of the valley, and entering Bear Creek just below the dam. A crib dam, 13 ft. in height, was built near the head waters of this creek, forming a storage reservoir with a capacity of approxi- mately 1,500,000 cu. ft., which was sufficient to operate the sluic- ing five to seven days, aided by the natural flow of the creek. This storage proved very useful, as the stream fluctuated rapidly with weather conditions, running very low in dry periods or in freezing weather. The water was diverted at a point about half a mile from the dam site, and carried- by means of a 10-in., spiral- wound wood-stave pipe to a head-box above the borrow pit. This pipe had a capacity of approximately 7 cu. ft. per second. From the head-box to the borrow-pit, a distance of about 400 ft., an 8-in. slip-joint riveted steel hydraulic pipe No. 12 gage was laid. A gate was provided at the head-box and two 2-in. standpipes installed as air valves. Care was taken to anchor this pipe, espe- cially at all angle joints. A Y-piece was installed just above the borrow-pit, with one pipe leading down the west side, and the other down the east side of the pit. Both were provided with gate valves near the Y. The monitors were connected directly to these pipes, which were shifted about as the progress of the work required. The static head at the nozzles ranged from 125 to 225 ft., giving discharge of from 3 to 6 cu. ft. per sec. Nozzle tips of 3 and 4-in. diameter were used. Pumping Plant. A pumping plant was installed just below the dam near the creek, to be used whenever the gravity supply ran low, and so avoid, as far as possible, delays in sluicing operations. This was considered necessary as it was impera- tive that the dam be completed in time to store water for use during the summer of 1912. The plant contained two three-stage centrifugal pumps, 6-in. discharge, 1,000 gals, per minute ca- pacity, the pumps being driven by steam engines, equipped with four 50-hp. boilers. Wood cut near the site was used for fuel. When running at full capacity, about 25 cords were burnt per 24 hrs. This was delivered at the plant at an average total cost of $3.50 per cord. The small borrowpits south of the dam were operated entirely by water from the pumps. For lighting the works, 16 c. p., incandescent lamps, were strung on each deck of the main flume and laterals, the power being generated by a D. C. 100-amp. 125-volt dynamo, operated in connection with the pumping plant. Sluicing Flume. A main flume (Fig. 24) of three decks was erected to carry the sluiced materials from the borrow-pits into the dam. This flume extended the full length of the dam, parallel to the axis, and with its center-line 8 ft. upstream from the up- 1230 HANDBOOK OF EARTH EXCAVATION stream edge of the crest. It was so located in order to be clear of the cut-off trench, but ordinarily it is better practice to keep the flume within the lines of the crest so that as the fill ap- proaches the crest, any overflow from the flume will not tend to wash out the newly formed slopes. A flume box was carried on each of the three decks. The pav- ing blocks used in the bottom of the boxes were cut on the site, and it was found economical to select the best fir timber for these. It was necessary to replace these blocks after the passage of about EnQ&Contq. Fig. 24. Main Sluicing Flume Bear Creek Dam. 25,000 cu. yds. of borrowpit material, and even before this they would become so badly hollowed out and worn as to interfere considerably with the flow of the sluiced material. There was but slight wear on the sides of the flumes, the original boards lasting throughout the work. A grade of 6% was used on the main flume, and this proved to be as light a grade as could be used with the dense heavy material which was found in the bor- rowpits here. Lateral flumes, branching off from the main flume, and then curving and extending along near the face of the slope and parallel DESIGN AND CONSTRUCTION OF EARTH DAMS 1231 to the axis, were erected to distribute the material along the edges of the rising embankment. Two types of laterals were used, ac- cording to the construction of the flume-box. The longer and more permanent laterals had a box with flush or butt joints and of practically the same construction as the main flume box, also the same grade 6% was used on these. The material was dumped by means of gates or openings in the sides of the box, and where necessary for the placing of the material, spouts were attached to these openings. The box on the other type of lateral had telescopic or lap joints, and was of lighter construction throughout. Grades of 7 and 8% were necessary with these, be- cause of the loss of grade due to the lapping. The material was dumped from the telescopic boxes by simply displacing them at the joints where desired. As the slopes approached the crest, the material was distributed directly from the main flume by means of spouts. Sluicing. Sluicing was started Sept. 1, 1911, and carried on as nearly continuously as possible in day and night shifts of 12 hours each. Delays were encountered due to weather and flood conditions, so that sluicing operations were maintained 67% of the total elapsed time after starting. However, the fill was completed April 15, which was earlier than had been anticipated. Weather as cold as 5 F. above zero was experienced, and the snow on the ground reached a depth of about 3 ft. The extreme cold interfered with the flow of the sluiced material by the freezing along the edges of the sluiceways and the formation of ice on the sides of the flumes. Also the ice on the sluicing pond attained considerable thickness, but this was overcome by laying steam pipes around the edge of the pond, and introducing live steam from the boiler plant. With the outside temperature ranging from 10 to 25 F., it was necessary to operate the thawing system about 12 hours out of 48 to keep the pond comparatively free of ice. During the months of November and December some severe de- lays were occasioned by maintaining the temporary spillway through the dam. Further delays were due to a failure of the gravity supply of water, when suitable borrowpit material was not available at an elevation to be economically reached with pumped water. In the borrowpit, a nozzle was maintained on each side of the pit, the two being operated alternately in periods of about six hours. While the nozzle was in operation on one side, the crew would remove the boulders from the sluiceways, and put in the blast holes for breaking the ground on the other side. It was necessary to break all the ground with powder. " Gopher " holes were put into the base of the banks to a depth of from 10 1232 HANDBOOK OF EARTH EXCAVATION to 16 ft.; also in places where the 'ground was shallow down- holes were put in by driving 1-in. drill steel. r lhe larger masses resulting from the heavy shots were " bifll- dozed" and the whole further broken down with picks. Through- out the work the amount of powder used in the complete breaking of the ground ran remarkably close to ^4 lb. of powder per cu. yd. In the " Gopher holes " 25% dynamite was used, and 40% was used for " bulldozing." A fairly large proportion of the boulders were too large to be transported in th flumes with the amount of water available, and these had to be handled and wasted in the pit. They were re- moved from the sluiceway when the nozzle was not in operatic-n, and were generally thrown out on the side toward the center of the pit, so as to form a wall or dike which would confine the water in the sluiceway and tend to throw it in toward the bank. This had the effect of cutting out the sloping toe of the bank and keeping the face vertical, which was of considerable help in put- ting in the " Gopher holes." It is estimated that 10% of the total material removed was handled and wasted in the pit. Also when the sluicing was in operation, men were kept in the sluice- way with long, pronged rakes removing the larger boulders and keeping the material moving. It was found necessary to keep the sluiceways cleaned right down to bedrock, or the material would start to deposit and block up, even where the grade was as steep as 15 to 20%. The stream from the nozzle was fre- quently turned into the sluiceways to push the material. Later on in the work, flume boxes were carried up closer to the work- ing face, and this did away with much of the work of maintain- ing the open sluiceways on the bedrock. A donkey engine was used for pulling and removing stumps as they were undercut by the excavation. It was also used in re- moving large boulders, and a stone-boat was used to some extent in removing rock. Flume tenders were stationed on the flume to keep the ma- terial moving when blockades started to form. These blockades were fairly frequent, and when they occurred it was necessary to stop sluicing and run in clear water from the nozzle. Two men were kept on the lateral flumes to attend to the depositing of the material along the edge of the embankment. As the material was deposited from the flumes, the boulders and coarse gravel would form conical piles, while the lighter ma- terial was carried off by the water toward the sluicing pond, the material being graded and deposited as the velocity of the water decreased until when it reached the edge of the pond and the velocity was entirely checked, all sand, etc., was immediately dropped, and nothing but the fine clay silt was carried in to DESIGN AND CONSTRUCTION OF EARTH DAMS 1233 the puddle core. From the edge of the embankment when de- posited, the material formed a slope of about 5% until the edge of the pond was reached, when it dropped off abruptly at a slope of 1 to 1. The surface of the puddle forming the bottom of the pond was practically level. An average crew of eight men was employed in shoveling to slope the piles deposited from the flumes. Xo difficulty was experienced in maintaining the slopes, as the outer portion of the embankment was built up entirely of boulders and coarse material which gave stable, well-drained slopes. Boul- ders as large as 8 ins. in diameter were delivered through the flumes. By sluicing from different sections of the borrowpit, it was possible to select material with differing proportions of clay and coarse ingredients. This proved quite helpful, especially as the dam neared completion, for if the sides were building up too fast in proportion to the puddle, material could be selected that carried greater proportion of clay. The puddle core was examined on several occasions when the pond was drawn off, and showed no tendency toward stratifica- tion. The first few inches on the surface of the puddle was very light and fluffy, but at a depth of 2 ft. or so it became stiff and fairly solid, showing that it drained and solidified rapidly. An outlet for the sluicing pond was, in the earlier stages of the work, provided by a timber culvert extending in from the down- stream toe of the dam to a vertical shaft, also of timber. This shaft was carried up as the work progressed, the level of the pond being regulated by openings or gates in the shaft. The depth of the pond was usually kept at from 3 to 6 ft., according to the width desired for the puddle core. As soon as the embank- ment had reached an elevation such that the pond backed up into the north end of the cut-off trench, a deep narrow ditch was cut from this into the spillway, so that the pond would now dis- charge through this ditch, by way of the cut-off trench. This was desired in order that any current set up in the sluicing pond would tend to carry puddle material up into the north end of the trench, for it was feared that there might be a shortage of puddle for this portion, due to the narrowness of the dam section here. The level of the pond was now regulated by placing sandbags in the entrance to the ditch, and the waste water was discharged into the reservoir by means of a small flume. This was done simply as an extra, precaution in order that the fine material car- ried by the waste water might tend to silt up the reservoir floor. As the fill neared completion, the puddle core was carried up to high water elevation, and then, in topping off the* embankment, mixed material was dumped in directly from the flumes with- 1234 HANDBOOK OF EARTH EXCAVATION out maintaining any pond. The work of topping off was started at the south end, the water draining off at the north end. RECORD OF SLUICING OPERATIONS Gravity sluicing Pumping Number of 24-hr, days worked (214) 145 69 Actual sluicing time, hrs 2,347 1,084 Time efficiency, % 66 64 Average water used, sec. -ft , 5.6 3.0 Material placed in dam, cu. yds 92,490 32,015 Ratio of material to water, % 5.3 7.3 Cu. yds. per 24 hrs. straight time 640 460 Cu. yds. per 24 hrs. sluicing time 946 709 Cu. yds. per sec.-ft. of water '. 169 236 Cost. Following is a list of the average force employed in the borrowpit, and on the dam: BORROW-PIT CREW Day Shift 1 Foreman $5.75 6 Drillers (breaking ground), Iiy 2 hours at 30 cts 20.70 5 Laborers (rocking out sluiceways), 11% hours at 30c. 17.25 1 Nozzleman 4.00 Donkey engine crew 16.75 Night Shift 1 Nozzleman $4.50 4 Men (breaking ground and rocking out), 11% hours at 30 cts 13.80 CREW ON DAM Day Shift 3 Flume tenders on main flume, 11% hours at 30 cts... $10.35 2 Tenders on lateral flumes, 11% hours at 30 cts 6.90 8 Laborers building up slope, 10 hours at 27% cts 22.00 Night Shift 3 Flume tenders, 11% hours at 30 cts 10.35 2 Tenders on laterals, 11% hours at 30 cts 6.90 1 Foreman 5.75 Total labor cost _. .... $145.00 Powder for breaking, 1,000 cu. yds. rr 250 Ibs 30.00 $175.00 From this force account it is seen that when sluicing with gravity water, and placing 1,000 cu. yds. per 24 hrs., the normal capacity when no delays were encountered the powder and direct labor cost of taking the material from the borrowpit and plac- ing it to slope in the dam was practically 17% cts. per cu. yd. The cost for 7 months operation, including, in addition to pow- der and labor costs given above, all labor and fuel and supplies for pumping plant operation and maintenance, superintendence, and all labor and material for maintenance and extension to pipe lines and flumes, was $54,277, which for 127,035 cu. yd. is 42.5 cts. per cu. yd. DESIGN AND CONSTRUCTION OF EARTH DAMS 1235 1236 HANDBOOK OF EARTH EXCAVATION A summary of the material placed in the dam is as follows: Rock from spillway cut 8,285 Material from cut-off trench 5,700 Sluiced from borrow-pit (measured in excavation) 129,364 Total cu. yds 143,349 Completed structure (measured in embankment) 148,390 Excess of embankment over excavation measurement, 3.6% 5,041 The figure given above for excess or swell would be modi- fied by two conditions. (1) The amount of fine material lost with the waste water from the sluicing pond would, if accounted for, increase this figure. (2) In measuring the excavation in the borrow-pit, the piles of waste rock left in the pit were considered as solids. If the voids in these were corrected for, it would tend to decrease the above figures. It is evident, however, that with no losses there should be a considerable excess of embankment over excavation in taking a material such as was found in the borrowpit here which as far as voids are concerned was practically a natural concrete and grading it into coarse and fine material. Dam Construction by Cars and Hydraulicking. In Engineer- ing and Contracting, July 19, 1911, H. L. Bickerson describes a method of constructing an earth dam across the Willow River, Oregon, in which the material was hauled to the embankment in cars and washed into its final place in the dam by nozzles. Fig. 26. Section of Willow River Dam. To secure good drainage from the lower side of the structure, rock fill, approximately 100 ft. wide on the base and 25 ft. high, was placed across the canyon on the lower toe of the dam. Rock was secured from the lava cap on the north side of the canyon, which was shot down the hill and placed by two 9 x 14-guy der- ricks with 1-yd. steel skips and small push cars. The rock stripped from the surface of the site and excavated from the cut- on trenches was also wasted at this point. A dry earth dyke was extended across the canyon on top DESIGN AND CONSTRUCTION OF EARTH DAMS 1237 of the rock fill. The material was delivered in trains of five 5 l /2 -yd. cars with a dinkey engine. The end car of the train was made to dump endwise, thus extending the dike in that direction, while the other four cars were dumped toward the center of the dam, the material from the side dump cars being washed to- ward the center of the dam, the material from the side dump cars being washed toward the upper toe, where a low dry dike was maintained, with water forced through a l*4-in. nozzle under pressure produced by a 750-gal. Knowles Underwriters pump. The lower dike was kept enough higher than the upper one so that the puddle containing the finer and impervious material was always nearer the upstream face of the dam, and the coarser material in the lower half of the structure, any excess water being drained out through and over this low upper dike. The sluiced material was usually solid, and it was possible to walk on any part of the puddle shortly after water was turned off. Tests made during construction showed that the weight of the ma- terial in the pits averaged 104 Ibs. per cu. ft., and in the dam, thoroughly saturated, 123 Ibs. The quantities as measured in the dam checked the quantities computed from cross-section of the material pits within 2%%. Trains placing the earth fill consisted of five and six cars, the end car being a rebuilt car to dump endwise, thus extend- ing the dike across the canyon while placing material into the dam. The dump crews consisted of five men, three on the dump shoveling and clearing track, and two working the nozzle in the sluicing operation. Train crews consisted of engineer and brake- man; shovel crew consisted of engineer, craneman, fireman, and four pitmen. The operations were carried on with one Model 40 Marion shovel with l l / 2 -yA. dipper, two 14-ton Vulcan locomotives, and sixteen 5y 2 -yd. Peteler two-way dump cars, all standard gage. The material was sluiced into place by a 750-gal. Knowles Under- writers pump, served by a 60-hp. Kewanee boiler, and the rock fill was placed with two 9 x 14 American Hoist & Derrick Co.'s guy derricks. Placing earth from the borrow pits was commenced on Aug. 12, 1910, and on Jan. 22, 1911, the dam was completed to the 100-ft. elevation, 286,000 cu. yds. having been placed. The work was carried on in two 10-hr, shifts, laying off one shift per week for general overhauling and repairs to plant. The best monthly run was in September, 1010, when 63,570 cu. yds. were placed in 55 shifts, or an average of 1,156 cu. yds. per shift. The average haul from pits to dam was 2,500 ft. The pits when opened up were 1,200 ft. in length, with an 18-ft. face. For the completion of the structure to 125-ft. elevation, new pits are to be 1238 HANDBOOK OF EARTH EXCAVATION opened up directly north of the dam and the excavation thus made is to serve as the permanent spillway. In the preparation of foundations, 19,000 cu. yds. of material were excavated, all by hand, and wasted both outside and inside the slopes of the dam. This material consisted of large boulders, brush and vegetable matter, soil and silt, part of the excavation being wet, and all being transported either by wheelbarrows or small push cars. The cost per cubic yard for this work was $1.28. The cost of 9,000 cu. yds. of rock fill, including cost of drilling and shooting, was $1.41 per cu. yd. This cost also includes transporting to place, 1,117 cu. yds. of concrete in the outlet tunnel and controlling works was $14.82 per cu. yd. The cost of the earth fill was as follows, per cu. yd.: Excavating and Loading: Labor drilling 2.3 Labor shoveling 4.7 Powder 2.7 Fuel 3.3 Total 13.0 Hauling and Placing: Labor, track _..... 1-4 Labor, dumping and sluicing 10.6 Fuel, engines and pumps '. 6.4 Total 18.4 Grand total, cts. per cu. yd 31.4 This gives a cost per cubic yard for labor of 19 cts., and for material of 12.4 cts. The wages paid were as follows per 10-hr, day: Common labor $2.25 to 2.75 Steam shovel enginemen , 6.17 Steam shovel cranemen 4 67 Locomotive enginemen 4.00 Carpenters 4.00 to 4.50 The average cost of lumber at the site was $25.00 per M ft. B.M.; eost of cement $4.46 per bbl., and cost of coal $13.50 per ton. Hydraulicking the Los Angeles Dam. Engineering Record, Feb. 3, 1912, gives the following: The South Hawaii dam of the Los Angeles Aqueduct was composed of earth delivered in dump cars and jettied to place by streams of water delivered from nozzles. The dam is designed to contain 559,750 cu. yds. of earth, exclusive of the contents of the cut-off trench. It is 1,523 ft. long and has a height at the center of 91 ft. The width at the top is 20 ft. and the slopes are 2y 2 to 1 on each side. The bed rock is overlain with a decomposed tufa shale. Test pits 75 or 80 ft. deep were dug and the soil stood up without tim- bering. A trench was then excavated by steam shovel to a depth DESIGN AND CONSTRUCTION OF EARTH DAMS 1239 of 14 ft. along the axis of the dam. This was filled with water and within a week the ground settled 12 ins. for distances as great as 75 ft. each side of the trench. This proved that it was necessary to take the cut-off trench to bed rock, which was reached at a depth of 120 ft. Ground water was encountered at a depth of 75 ft. The material was mainly shale soils with a 3-ft. stratum of sand and gravel at the bottom. This trench was excavated with light, stiff-leg derricks, and dump buckets. The spoil in the dumps was hauled to the lower toe of the dam with scrapers. The trench was timbered through- out. The impervious core was composed of clay, which was excavated by an electric shovel and hauled an average of 1,000 ft. in dump wagons to the side of the trench, into which it was pushed by a road grader. The trench was kept filled with water, and the force of the fall thoroughly compacted the clay. The cost of the cut-off trench (27,032 cu. yds.) was as follows: Labor $22,422 Live stock 2,280 Materials and supplies 1,843 Electric power 957 Freight 630 Total excavating cost $28,132 Cost per cu. yd $1.04 Timbering : Labor $15,144 Live stock 457 Other charges " 25,790 Total for timbering $41,391 Cost of timbering per cu. yd $1.53 Cost of puddle fill per cu. yd 0.315 Grand total cost per cu. yd $2.885 The material for the body of the dam was excavated from a pit 1,000 ft. from the dam with a 60-ton Marion steam shovel. The soil was loaded into 4-yd. double-side dump cars, and hauled in three trains of 7 cars each by three 18-ton Vulcan locomotives, running on a 3-ft. gage track. While one train was being loaded, another was in transit and the third was being dumped. The grades were 3% up-grade for loaded trains and 6% down-grade for empties. The shovel had a 2.5 yd. dipper; two dippers filled each car. When conditions were favorable it required 4 mins. to load a train. From 400 to 500 cars were loaded in two shifts. The day shift accomplished about 50% more than the night shift. The best day's run up to Oct. 31, 1911, when 184,000 cu. yds. had been placed, was 700 cars or 2,100 cu. yds. The hauling track divided when it reaches the dam, a branch running up along each toe. Thus two walls were built up. 1240 HANDBOOK OF EARTH EXCAVATION The waters of two streams were discharged in the space be- tween these walls, and in the pool thereby formed two steel pon- toons were floated. These pontoons were 20 x 10 x 2.5 ft. in size. Each carried a 6-in. centrifugal pump direct connected to a 30-hp. electric motor. Power was supplied through an insulated cable thus allowing changes in the location of the pontoons. The water was discharged through a 2-in. nozzle against the banks of earth dumped from the trains. The earth was washed down towards the center of the pool, the coarser material remaining at the edges of the pool and the finer stuff going to the center. This center material was very fine and clayey. The use of two tracks permitted one to be shifted and raised while the other was in use. The cost of the first 184,000 cu. yds., including 50,000 cu. yds. placed by wagon work, was 22 cts. per cu. yd. The cost of the work complete was estimated to be about 15 cts. per cu. yd. Hydraulicking the Abott Brook Dike. Engineering and Con- tracting, Feb. 26, 1913, contains an article descriptive of the plans and methods used in constructing the Abott Brook Dike, an earth dam located on the westerly side of Sawyer Lake, near the headwaters of the Androscoggin River. This dike is 900 ft. long, 165 ft. wide at the base, and about 16 ft. wide at the top, and has a 6-in. plank core composed of two layers of 3-in. plank. The total volume of the dike is 46,000 cu. yds., of which amount 1,600 cu. yds. were placed by manual labor to form the toe of the dike, and for the puddle fill at each side of the core in the cut-off trench. About 31,165 cu. yds. were pdaced by hydraulic sluicing methods. The plant used comprised two 150-hp. turbine driven pumps, direct connected to 3-stage, 8-in. centrifugal pumps, designed to run at speeds ranging from 1,800 to 2,000 r.p.m. The main pressure line of pumps to borrowpit was 600 ft. long and 10 ins. in diameter. Branches connecting this main with a 2-in. giant were 350 ft. long and 7 ins. in diameter. Steam to run the turbines was furnished by a battery of 8 boilers, consisting of two 50-hp., three 40-hp., and three 30-hp., and a feed water heater. Steam pressures at the boiler ran from 80 to 150 Ibs., and the pump pressure was from 45 Ibs. per sq. in. down to 20 Ibs. per sq. in., depending upon the elevation, with an average of about 45 Ibs. per sq. in., with a 2-in. monitor discharge stream. Two water jets, with a pressure of from 20 to 80 Ibs. per sq. in., were directed against the bank in a borrow pit at the northerly end of the dike. The force of the water was so great that although the nozzles were securely mounted on swivel bases, a long lever had to be attached to each nozzle to enable one man to control it; under certain conditions, two men were required. DESIGN AND CONSTRUCTION OF EARTH DAMS 1241 The flumes were rectangular wooden structures, supported on wooden trestles, built with even slopes from the borrow pit to the dike. The main flume was about 1,000 ft. long, and the main trestle about 40 ft. high at the tallest point. The laterals discharged at the edges of the fill, and in this way the loose stones and coarse material remained at the .edge, and the finer and silt were carried toward the center. The dam was situated far from the railroad, and it was diffi- cult to get a sufficient supply of coal. The little that could be obtained cost $20 per ton, and it became necessary to use wood for fuel. A total of 1,860 cords of wood were burned. Counting the 55 long tons of soft coal used as equivalent to 2 cords each of wood, the equivalent of 1,970 cords of wood were burned. The material was a glacial drift of sand, gravel, clay, and small stones so firmly compacted that it was found advisable to resort at times to dynamite. Holes about 8 ft. deep and 8 ft. apart were drilled, and about 6 Ibs. of 16% dynamite used per hole, and set off in batteries of from three to seven holes. Sluicing was carried on for 32 ( 10-hr.) days and for 68 (24-hr.) days; equivalent to 82 full days. The men worked on two shifts of 12 hours each, working week days and Sundays con- tinuously, the only stop being for unavoidable delays in clean- ing and repairing. The average yardage placed per day was 380 cu. yds.; the best weekly record was 3,891 cu. yds., an aver- age of 556 cu. yds. per day. These measurements were deter- mined by weekly cross sections of the embankment. The volume of solids moved in the water averaged a little better than 6%. Hydraulicking the Somerset Dam, Vt. Engineering News, Dec. 25, 1913, gives the following: This dam is located at what was Peck's Mill in the town of Somerset, Vt. It is 2,100 ft. long on the crest and has a finished height of 106 ft. It contains about one million cu. yds. A cut was opened with steam shovels to a borrowpit on the west side of the dam. This cut was run for about a half mile on an upgrade of 5% maximum, passing through a number of rock ledges. The location of the pit was a gently rising slope which by test pits had been found to contain a glacial drift with some 30% of clayey material and running from very fine ma- terial to sand, gravel and boulders, well graded. The pit. was opened up on two levels and, as the height of the dam increased, the shovels worked farther up the hillside, the result being that the downgrade from the pit to the dam was gradually decreased, though not much. At first there were seven dinkey locomotives (19-ton) and 70 4-yd. narrow gage cars. For the last season's work, however, three more locomotives were put on and 30 more 1242 HANDBOOK OF EARTH EXCAVATION cars, making in all 10 locomotives and 100 cars. During the last season too, a borrowpit was opened up on the east side of the dam and a third 2%-yd. steam shovel put in, reducing the length of haul for a considerable part of the fill. First, in starting the fill, a couple of 20 to 30-ft. trestles were run out some 50 ft. inside the upstream and downstream toe lines of the dam, and material from the pit was dumped off these, work- ing out from both ends of the dam. These four toe fills were thus pushed out until the water was reached when the gap in the upper dike was filled in. When this was done, the water rose until the entire flow was through the conduit. The pool be- tween the two dikes could then be drained through the gap in the lower dike and the remaining work of stripping the site completed. When the work was in this stage, a pumping plant was built just above the dam, taking water from the reservoir for 6-in. supply pipes laid along both trestles. There were in this plant three 60-hp. locomotive boilers, two compound duplex pumps rated at 750 gals, per min. at 200 Ib. pressure, and one smaller pump as a spare unit. Only 150 Ibs. pressure was held on the pipe lines, however. The lines were fitted every 50 ft. with T fittings and valves for connecting on lengths of 3-in. rubber sluicing hose fitted with 1%-in. taper nozzles mounted on port- able wood stands as monitors. The material dumped from the trestles was undercut with streams from these nozzles and washed down into position. A pool was created between the two dikes and the finer material settled in the center. At times alum was used in the sluicing water to increase the precipitation of clayey material, but this was finally abandoned as unnecessary. An 18-in. concrete pipe was carried up from a hole in the outlet conduit. Through this the excess water was drained and the depth of the pool regulated, being allowed to vary between 10 and 20 ft. The outside faces of the two dikes were filled with coarser material and boulders from the pits, and this, on being washed down into place, gave satisfactory rock face without riprapping. When the washed fill reached the level of the trestles, the tracks were shifted inward. Five heights of trestle were run in during the work on the dam. The old timbers were not pulled. Samples were taken at each 5 ft. along the length of the dam to see if sufficient fine material was being deposited to build up an impervious core. In sounding the center pool the bottom at each stage was always found quite hard, and the examination of the accumulated samples shows that the fine material has considerable binding property. The two years oc- cupied in construction, 1911 to 1913, gave opportunity for set- DESIGN AND CONSTRUCTION OF EARTH DAMS 1243 tlement which was small, but the dam was carried to an ex- cess height of 4 ft. to provide for future shrinkage. Accident to, and Reconstruction of the Charmes Dam. En- gineering and Contracting, May 29, 1918, gives the following: The Charmes Dam in France was completed in 1906. It is about 1,190 ft. long, 55 ft. high, and 22 ft. wide on top. The up-stream face is built in 5.5-ft. steps, giving a general slope of iy 2 to 1. The down-stream slope is flatter and has a slightly concave force. The dam was constructed in a series of layers of good clay mixed with 5% of fine crushed rock, each layer being puddled and rolled with a corrugated roller. The layers were 5 ins. thick before rolling, which reduced them to 3 or 4 ins., mak- ing the earth remarkably hard and compact. Allowance was made so as to make it follow the required slopes, and the layers were put in rapidly to be always on freshly puddled material. The face was paved or covered with concreted slabs 8 ins. thick, with clay joints. After the dam had been in use three years a longitudinal fissure developed a little above the top bench on the inside slope. The water was being drawn off at the time, and as its height was lowered a slide developed. The amount of the slide was about 26,200 cu. yds. It was decided that the re- pairs would be made of the same clay compacted by the same process to a proper hardness, and for security it was decided to reinforce the lower part 8 ft. above the cut-off wall, the foundation of it being considered perfectly good. Two other conditions were adopted, first, the physical improvement of the Charmes clay by the addition of a considerable amount of small pebbles; second, the construction of buttresses in the re- inforcements. The necessity of adding pebbles to the, clay to be used for the puddled wall 48 ft high on a slope of 1.5 to 1 was deter- mined upon, which plan had been used at the Liez dam, and, probably on account of which it has stood for 25 years; and was used in the Wassy dam repairs. Such a mixture is very much superior to any other for puddled material for dams. There being no pebbles or gravel in the vicinity, it was neces- sary to resort to crushed stone which was a valuable material and could not be used wastefully. Experiments were made to determine the proper amount to be used and 20% was finally adopted as best. The earth work for the repairs was done largely by hand, using small horse drawn cars to transport the materials. The addition of buttresses was considered necessary, and it was decided they need not go all the way up the face of the 1244 HANDBOOK OF EARTH EXCAVATION dam, as insisted upon by some constructors, but only to be carried up to the height of the danger zone or 29 ft. above the top of the cut-off wall. They were 4 ft. 7 in. thick and aver- aged 49 ft. in length. They were built of concrete similar to that employed in like work. Where they join the cut-off wall they are enlarged in the form of a girder, thus approaching the form of a solid of equal resistance. Particular precautions were taken to prevent " water ways " where water would follow the junction of the puddled material and the concrete masonry, so the buttresses were put in at a time and in a manner that they would not interfere with the rolling of the puddled material. The plan for the restoration comprised a complete drainage system from the top to the bot- tom. The paving slabs were made by crushing the broken ones from the former work, using an excellent sand to make the concrete. The new top step was an improvement over the old. The repairs were made from 1909 to 1911 and were quite difficult, as the year 1910 was unfortunately very rainy. The cutting away of the slide and old face was done in the first 6 months and all the work was carried out under considerable difficulty. The total cost of the work was 500,000 francs. A Slide on the Stanley Lake Dam. John E. Hayes, in Engineer- ing News-Record, May 31, 1917, gives the following: This dam was hastily built. At first material was dumped from trestles on the up and down stream toes into a pond of water that was kept between the trestle embankments. At the 30-ft. level it was found that the puddle material was not drying out. Thereafter up to 64 ft. elevation, material was scattered in thin layers with teams and scrapers over the puddle core area, sprinkled by means of hose, and compacted by the team travel. Above the 64-ft. level to the top of dam at 70 ft. elevation the trains were depended upon for consolidation. The dam was completed in 1912. In the summer of* 1916 while water was being drawn from the reservoir a large part of the up-stream face of the dam slid into the reservoir. Approximately 88,000 cu. yds. of material was displaced. Owing to the different methods of construction adapted this dam was not a homogene- ous structure. Slide on the Calaveras Dam. Engineering and Contracting, July 10, 1918, and Jan. 8, 1919, gives the following: The Calaveras Dam was being built about 36 miles south- east of San Francisco by hydraulicking. Its top length was to be 1,300 ft. and its top width 25 ft. The upstream slope was 3 to 1; the downstream slope, 3% to 1; and the maximum DESIGN AND CONSTRUCTION OF EARTH DAMS 1245 distance between upstream and downstream toes, 1,312 ft. Its finished height at the center was to be 210 ft. above ground level, plus 30 ft. above the bottom of a wide excavation to solid bed rock. About half the material in the dam was a dry rock fill used in both toes; the rest was an earth fill deposited by hydraulic sluicing. The earth fill was half clay and half sand and gravel hydraulicked from nearby hills. The coarse material was crushed before entering the conveyance pipes. The hydrau- licked material was dumped on the edge of the pool, thus per- mitting the clay to separate and flow to the center of the pool. The failure did not occur without warning, but the great mass of earth slid out within five minutes after it started to go. There had been a slight horizontal movement of the upstream slope of the dam as early as June 18, 1917, whereupon sluicing was discontinued until Feb. 12, 1918, except for a period of 12 days in the summer of 1917. On March 4, three weeks after sluicing had been resumed, another slight horizontal movement of the upstream face occurred. Sluicing was again stopped, but- 10 days later, March 14, the failure occurred. The depth of the hydraulic fill in the center was 155 ft. at the time of failure. In five minutes 800,000 cu. yd. slid out, leaving about 2,000,000 cu. yd. still in place. The 2,000,000 includes the whole of the downstream part of the dam. At the time of the failure the reservoir was partly full, the water being about 55 ft. deep. The cost of replacing the upstream material will be more than $500,000. The original estimate of the cost of the complete dam was $2,500,000, and it was to have contained 3,085,000 cu. yds. Beginning March 16, 1916, it was the practice to have a man periodically force a l l / 2 -in. pipe into the hydraulic fill, and this practice was continued till Jan. 24, 1917, when the "ball test" was adopted. The material in the core was so plastic that the pipe could be forced down to a depth of 90 ft. On Feb. 12, 1917, the ball test was begun, and it was found that a 6-in. cast iron ball sank by its own weight 45 ft. into the soft clay fill, or half the depth that the pipe was forced. By July 27, 1917, the depth of penetration of the ball was 35 ft.; a month later it was 12 ft.; and on Jan. 21, 1918, it was only 5 ft. From this test it was apparently reasoned that the fill had dried out sufficiently to be safe. See Chapter XVIII for a description of the construction of this dam. Bibliography. "The Design and Construction of Dams," Ed- ward Wegmann " Reservoirs for Irrigation, Water-Power and 1246 HANDBOOK OF EARTH EXCAVATION Domestic Water Supply," James Dix Schuyler "Earth Dams," Barr Bassell. "The Bohio Dam," George S. Morison, Tran. Am. Soc. C. E., Vol. 48, 1902 " Hydraulic Fill Dam of the Necaxa Light and Power Plant," Trans. Am. Soc. C. E., Vol. 58, 1907. CHAPTER XXI DIKES AND LEVEES This chapter relates solely to the design and construction of earth embankments along rivers, lakes and oceans, to exclude water from low lying lands. The reader is referred to Chapters VI and XX for data on making embankments water tight. For methods and costs of protecting embankments with brush mat- resses and sheet piling, and for surfacing slopes with concrete and stone masonry, see the author's " Handbook of Cost Data." The Location of Levees. This is discussed by Arthur A. Stiles, State Levee and Drainage Commissioner of Texas, in a report is- sued in 1913. The problem involved consists in providing a channel for the flood flow of the stream. This can be done either by confining it to the usual channel between high levees or by increasing the channel section by building the levees away from the river. It is a well-known characteristic of over-flowed river valleys that the ground surface, rising gradually from the base of the Hign Water Level Fig. 1. Typical Cross-Section of River Channel, Showing Prob- able Distribution of Current Velocities in Ft. Per Sec. and Their Influence Upon Levee Positions. foothills at each side of the flood-plain, reaches its greatest ele- vation at the banks of the channel overlooking the principle stream. Hence, a levee to be of minimum height and maximum protection should be built along this crest, but a stable position cannot be obtained so near the channel, and the distance which should separate the proposed levee from the adjacent stream bank may be regarded as the result of a compromise between practical interests, and other more technical requirements. Fig. 1 shows the advantage of setting the levee back to where it will be subjected only to the wash of slow moving water. Land lying between the levee and the normal channel is, in a way, wasted, as it should be kept clear to permit the passage of water. Where levees are built on a tidal stream fences of brush should be built across this waste land from levee to channel at frequent intervals. These will in time build up the waste ground that it will fprffi a considerable reinforcement to the levee. 1247 1248 HANDBOOK OF EARTH EXCAVATION Design of Dikes for Salt Marsh Reclamation. This is dis- cussed in Engineering and Contracting, Sept. 6, 1911, as follows: Dikes for tide marsh reclamation are made of earth, but they differ from the levees used on rivers in that they must be so lo- cated and designed as to withstand the action of the waves. The best protection against waves is to have the dike a safe dis- Form of Pike Made of Clay or Clayey Loom Form of Dike Mode of Sand or Sandy Loam iff form ofDiteMode of Muck Soil Fig. 2. Typical Dike Sections for Different Materials. , L4 L /--"' ^.x" * j { W/ .J Eng.V Contg. u 5~ ^fvZ&r Muck Ditch Muck Ditch Fig. 3. Method of Preparing Base for a Dike. t I <:? '' i- ! '.-.;:' fv! -,.}' j tance from the shore, never less than the width of the base of the dike, and a greater distance if wave heights require it. The cross- sectional dimensions depend upon the material available for con- struction and the length of time the water will remain against the dike. Three forms of dike sections are shown in Figs. 2 and 3. The ground is cleared and broken up under the base, and where very Avet is frequently ditched along each edge of the dike about DIKES AND LEVEES 1249 6 ft. inside the toes, as shown by Fig. 3. The dirt from these ditches is used for the toes of the dike and the ditches them- selves are filled with the new material from which the embank- ment is made. It is preferable practice to borrow the material for embankment from the water side. The borrow pits should be located well away from the toe of the dike. Design of a Dike for Tidal Marsh Reclamation. Engineering and Contracting, Nov. 15, 1911, describes the reclamation of marsh land on a tidal stream at Cape Cod, Mass. A dike 900 ft. long, 22 ft. wide on top, was built. See Fig. 4. A roadway runs along the top of the dike the crown of which is at grade 17.7 ft. above mean low water, or about 7 ft. above ordinary high tide. The maximum bottom width is about 68 ft. The filling ^Roadway OUTSIDE Fig. 4. Typical Section of Dike, Herring River Reclamation, Cape Cod. was obtained from pits in the hills at each end of the dike, and was hauled in automatic side dumping cars of about 3 cu. yd. ca- pacity. The 20-in. gage track was laid so that the cars ran out from the pit by gravity; the empty cars were pushed back on the level track along the dike by two men, and drawn up the grade to the pit by a rope and hoisting engine. The sand was placed at a labor cost of about 8 ct. per cubic yard, the haul being about 450 ft. Along the center line of the dike from end to end 4-in. splined spruce sheeting was driven about 6 ft. into the river bed, the top of the sheeting extending nearly to the top of the dike. The up- stream slope of the dike is backed by a 6-in. layer of granite chips. Some of the blocks in this facing weigh more than 3 tons, and the whole construction appears to be very safe and durable. Above the heavy facing the protection is the same as on the upstream slope. The top of the dike is surfaced with a mixture of fine sand and clay silt, and is sufficiently compact to make a fair roadway for light teaming. Levee Sections on the Mississippi and Sacramento Rivers. HANDBOOK OF EARTH EXCAVATION Fred H. Tibbitts, in Engineering and Contracting, Apr. 9, 1913, gives the sections shown in Fig. 5. The California levees are not subject to flood for such long periods as those on the Mississippi. Min Berm Lonasiae IW fF>rr ;.TTTTV : : < ;-! '. !, MuckDitchy Banquette-' Trrrr I 1 ' n"f'"n"r ( - STANDARD CROSS SECTION OF MISSISSIPPI RIVER COMM. Borrow Pit \or\L --H/0V- STANDARD LEVEE CROSS SECTION OF UPPER YAZOO LEVEE DISTRICT 3' for River Levees ^ Iff i 5 Io6' For bock Levees" BE23S?C^w OABNEY COM. AND CALIFORNIA DEBRIS COMM FOR SACRAMENTO RIVER NATOM AS CONSOLIDATED OF CALIF. RECLAM DiST.NlOOO RECLAMATION DIST. IM ADOPTED PLAN FOR BACK LEVEES WEST SACRAMENTO Co. RIVER LEVEE RECLAM. DIST. N a 900 ftemf Concrete Facing^} -L ion?. t~.iff-* __j^fe^fwi. WEST SACRAMENTO Co. BACK LEVEE RECLAM DIST. N900 ^^ mz. ~^&&^^-m*m ?^^*v?v3 -Borrow ^FSpfJT NETHERLANDS FARMS Co. PROPOSED BACK LEVEE IN YOLO BASIN Fig. 5. Standard Levee Sections on the Sacramento and Mis- sissippi Rivers. They are subject to greater wave action, and, being built of sand, they have not been so generally successful as the levees on the Mississippi. DIKES AND LEVEES 1251 Enlarging and Slope-Walling a Levee on the Wabash River. This is described by George C. Graeter in Engineering News, Jan. 4, 1917. This levee was built in 1895 at a cost of $74,500. A total length of 8.6 miles of levee reclaimed 7,500 acres of bot- tom and marsh land which now has a value of $100 per acre. In 1904, $4,000 was spent for repairs; in 1912, $18,300 for re- pairing breaks; and in 1913, $14,500 for repairing breaks and for placing concrete at the riverside toe of slope on 12,500 ft. of the upper end. Maintenance has cost $14,000 (or about $650 per year), most of this being spent in digging out ground-hog and mole burrows and mowing the levee. Thus the cost of repair and maintenance up to 1916 was over 66% of the first cost of con- struction, and the levee was still in' poor condition. Grade S'abore 1913 Flood 'brief 3 ' Fig. 6. Wabash River Levee Showing Earth Enlargement and Concrete Facing. . In 1916 the Levee Committee adopted a plan of raising the levee and facing it with concrete, see Fig. 6. The concrete extends for about 12,500 ft. from Riverton to a sand ridge. It consists of 199,100 sq. ft. of facing and 154.3 cu. yd. of footing. The earth enlargement on this upper section averages 231 cu. yd. per 100-ft. station; on the next 20,000 ft. beyond this ridge it averages 163 cu. yd. per station, and then for about 6,700 ft. the average is 240 cu. yd. per station. The total enlargement, including a short stretch of relocated levee, amounts to 88,000 cu. yd. On the section that is being concreted the earth enlargement (28,890 cu. yd.) is being put up by a reconstructed Monighan dragline excavator. The remainder of the enlargement is being constructed with teams, using drag and wheel scrapers. The shrinkage allowance was 20% for dragline work and 10% for team work. The top and land slope of the levee were plowed, and all stumps and brush were removed before placing the fill for the enlargement. The Levee Committee provided borrow pits with- out expense to the contractor. The specifications permitted ma- 1252 HANDBOOK OF EARTH EXCAVATION terial to be taken on either side of the levee, but required it to be taken on the river side where possible. No material was to be taken within 22 ft. of the toe of the old slope, and new pits were not allowed to be more than 3} ft. deep. The contract prices for this work were 20 ct. per cu. yd. for earth enlargement and $6.60 per cu. yd. for concrete facing. Levee Construction by Dragline Excavators on the Little River Drainage District, Mo. B. F. Burns, in Engineering and Contracting, July 18, 1917, gives the following: For the main diversion channel and levee a strip is cleared approximately 400 ft. wide. From this all brush logs and debris are removed. The stumps on the berms are cut to 24 in. above the ground, but elsewhere they are cut to such heights as will enable them to be removed with stump pullers, stump pullers and skidders being a necessary part of the contractor's equip- ment. As the work goes forward the floodway strip, 900 ft. in width, is cleared and, before the final completion of the sys- tem, all logs, brush and debris are removed so as to permit of the free movement of the flood water over it. Following the clearing of the channel and levee base area the stumps are broken with dynamite and removed and the roots grubbed out so that the material will be practically free from fibrous matter when excavated from the channel and placed in the levee. The work was divided into two contracts. Contract "A" including that part from Allenville west, and contract " B " that part east of Allenville. The operation of stripping and digging muck ditch on Con- tract " B," is done by caterpillar tractor having a boom length of 70 ft. and a bucket capacity of li yd. The machine works over the channel area for a stretch of approximately 2,000 ft., removing the surface material for a depth of 6 in. or more, and depositing the same on the levee area at the limit of its boom reach. It then tracks back and begins stripping the levee base area, removing the surface material to about the same depth as on the channel, and placing the stripping outside of the levee base area and also removing that taken from the channel, which it places with the levee stripping. As the machine moves over the levee base area it excavates the muck ditch, 6 ft. wide and 8 ft. deep, and places that material along the outer toe line of the levee. As the levee is finished, the stripping, which is quite free from roots and other material objectionable for levee con- struction, will be shaped into a banquette of such height and with such crown as the material will make. An experiment in the use of dynamite for the excavation of DIKES AKD LEVEES 1253 muck ditches was made soon after the construction started. The imick ditch at that point was but 3 by 4 ft. The experi- ment was not successful as the ditch was unsatisfactory. The character of the soil under the levees was determined by borings made to a depth of 11 ft., along the center line, at in- tervals of 300 ft. These borings indicated that at one point the soil was such that an ordinary muck ditch would not effectually cut off seepage. Further investigation showed the extent of that condition to but little more than 100 ft. along the center line of the levee, and, in lieu of a muck ditch, a wall of Wakefield sheet piling was driven. These were driven to a penetration be- Fig. 7. Movement of Dragline Machines in Constructing Levees. low the sandy strata and allowed to protrude 4 ft. above the surface, penetrating the levee to that extent. Two machines are required to excavate the main diversion channel. On Contract " B," the first machine is a Bucyrus drag line, having a 125-ft. boom and a 3^-yd. bucket. This machine tracks along the channel near the center line and excavates approxi- mately 65% of the material. This it places over the levee area in layers about 8 ft. in depth, making two lifts. In depositing the material for the first lift, the movement is clockwise and in placing the second lift it moves in the opposite direction. See Fig. 7. The earth is compacted by dropping at least 8 ft. The second machine, a Bucyrus drag line, 100 ft. boom, 4-yd. bucket, tracks along the berm and removes the remainder of the material in the channel. It likewise deposits the material in two lifts and operates in the same manner as machine 1. Usu- 1254 HANDBOOK OF EARTH EXCAVATION ally machines 1 and 2 are at leas; 2,000 ft. apart. Machine 2 carries the levee to its shrinkage grade and section. brnu The operations on Contract " A " are similar to those on Con- tract " B," with the exception that the stripping is removed and muck ditch excavation is made by the pilot machine, which also excavates about 30 per cent of the channel. Two Bucyrus drag lines, 100-ft. booms, 3^-yd. buckets, are in use on this contract. The material handles more easily if there is some water in the channel, but, if there is too much, it makes the material unstable for levee building and slides result. Except during periods of heavy rain, the stage in the channel is controlled by pumping, dams being left in the channel at intervals and the water pumped from the sections where operations are in progress. The crew of a drag line excavator, electrically operated, consists of the runners, who work in 8-hr, shifts, a foreman, three labor- ers, a helper and a spotter, who work 12 hr. The machines op- erate during the entire 24-hr, period. The following statement, covering the operations of the con- tractor for one year, is of interest: Total yardage, four electric machines 2,682,330 cu. yd, Total yardage, three steam machines, including stripping and muck ditch.. 980,750 cu. yd. Current consumed during year 1,952,240 K. W. H. Coal consumed during year 4,350 tons Grubbing during year 155 acres Dynamite used during year 133,000 Ib. Average number of men employed, contract " A," 102 men. Average number of men employed, contract " B," 187 men. The above indicates that under similar operating conditions it requires 0.756 K.W.H. per cu. yd. to excavate earth, and that 0.9 Ib. of coal is required for the same purpose. Levee Construction in Texas with Draglines. In Engineering and Contracting, July 17, 1918, O. W. Finley gives the following: The first levee work of any magnitude on the Trinity River in northern Texas was begun in June, 1914, when a levee 10 ft. high and 44,000 ft. long was built for the protection of 9,040 acres of very fine black flood land in Kaufman County. This levee has since been raised to 18 ft. height. The levee was con- structed by an old steam skid and roller dragline machine which has long since been junked and has now been replaced by 18 new machines, 15 of which are Monighan gas walking machines, one a Bucyrus mutipedal, one a gas skid and roller and one a steam skid and roller. The 18 machines are of the following types and sizes: All the small machines have vertical triple cylinder gas en- gines while all the larger or No. 2 and 3 machines, except the Bucyrus, have horizontal single cylinder gas engines. The Bu- DIKES AND LEVEES 1255 cyrus has a triple vertical type engine and is an excellent dirt mover. TJp to May 18, 1918, a fraction more than 100 miles of levee had been built in which had been placed 6,540,000 cu. yd. of earth. Seldom more than 15 of the machines are working at the same time, the others are moving from one job to another, but nearly 500,000 cu. yd. are being moved per month, or an average of about 30,000 yd. for each machine. The larger machines some- times excavate more than 60,000 yd. a month. The contract price for these levees is about 10 ct. per cu. yd. The cost per acre for reclamation varies from $14 to $70. It is stated that these lands are so valuable for agriculture that ex- penditures up to $100 per acre are justifiable. Machines for Building Levees. J. R. Slattery in Engineering News, May 25, 1916, gives the following: The floods of 1912 and 1913 resulted in a number of crevasses in the Mississippi River levees which it was imperative to repair before the next flood period. Recognizing the inability of existing team outfits on the river to handle this work economically, the Mississippi River Commission directed that careful consideration be given to the problem of selecting suitable mechanical devices for levee con- struction. TABLE I. AMOUNT AND YARDAGE COSTS OF MISSISSIPPI RIVER LEVEES Price per Fiscal year Cu. yd. cu. yd. 1882-90 1,672,619 28.83 1891-92 4 979,154 22.37 1892-93 793,365 21.12 1893-94 785,642 17.50 1894-95 1,326,255 11.19 1895-96 1,149,411 9.26 1896-97 256,153 11.70 1897-98 4,141,326 12.67 1898-99 2,845,342 11.67 1899-1900 1,840,340 17.30 1900-1901 614,940 13.52 1901-2 21,932 18.56 1902-3 841,589 17.21 1903-4 1,905,842 17.24 1904-5 1,040,708 17.40 1905-6 429,632 19.75 hjn! 1906-7 305,507 21.89 1907-8 918,504 20.55 1908-9 986,674 25.31 1909-10 303,878 22.08 1910-11 906,761 20.34 1911-12 420,260 11.64 1912-13 1,072,305 25.80 Specifications for levees above the Red River require that bor- row pits shall be 40 ft. from the base of the levee on the river side and 100 ft. from the base of the levee on the land side. Side 1256 HANDBOOK OF EARTH EXCAVATION slopes of borrow pits must be very flat. Below the Red River borrow pits may be within 20 ft. of the base of the levee on the river side and within 80 ft. on the land side. The generally smaller levees below Red River and the more liberal pit specifications for them made the selection of a suitable type of machine for their construction much less difficult than the selection of a machine for levees above Red River. The ma- chine selected was the dragline excavator, of the self-contained, revolving locomotive crane type, arranged to operate an orange- peel, clamshell or drag-line bucket at a radius of 90 or 125 ft. The machines are mounted on four-wheel trucks and are pro- vided with the necessary mechanism for performing the opera- tions of traveling and hoisting, rotating and operating a bucket. Track is provided for the machines to work on during low-water stages and barges from which to operate them during high-water stages. The barges are likewise used to transport the machines from one job to another. The crews of the machines are housed on quarter-boats. The first machine with its barge, quarter-boat, track and equipment cost approximately $40,000. The second and third machines purchased are stronger and of greater capacity than the first one, and the last machine purchased has been so successful as to warrant its adoption with minor modifications as a type for work in the Fourth District, particularly below Red River. This type machine will handle a 3-yd. orangepeel bucket or a 5-yd. dragline or clamshell bucket at a radius of 126 ft. from the center of the machine. The cost of machines of this type fully equipped and provided with a quarter-boat for the housing and care of crew and coal barge for supplying it with coal will be approximately $60,000. This figure does not include the cost of a barge from which to operate it during high stages and with which to move the machine from point to point. The cost of a steel barge suitable for this purpose is about $18,000. It will not be necessary to provide a barge for every machine. It is thought that with these machines it will be possible to place earth in the levee system, wherever rehandling is unnecessary, at field costs of from 5 to 10 ct. per cu. yd., exclusive of the cost of clearing and grubbing when this is necessary. When material can be placed in the levee without rehandling this type of ma- chine is believed to be the most economic for levee work. Above the mouth of the Red River the levees become much . higher than below the Red, and this fact, together with the more difficult pit specifications, necessitates greater reach on the part of the machines. The considerably greater reach led to the se- lection of cableway machines for trial in preference to drag-line machines. :^;i' >; '- ^ DIKES AND LEVEES 1257 1258 HANDBOOK OF EARTH EXCAVATION Above Greenville the average height of the levee system is 20.7 ft. ; the average width of the existing riverside pits is 258 ft. ; the average amount of material to be added to the existing levees to bring them up to the grade and section calculated to be neces- sary to contain safely 'such a flood as that of 1912 is 2,150 cu. yd. per 100 ft. station. In order to obtain this amount of ma- terial it is necessary to go out 63 ft. beyond the existing river- side pit. The outer edge of the resulting pit would then be 428 ft. from the center line of the crown of the existing levees. Even if this earth were all to be placed on the river side, dragline excavators to do this work without rehandling would have to han- dle their buckets on booms approximately 200 ft. long. See Fig. 8. A machine was sought that would take all the material from the river side of the levee beyond the limit of the old pits, and place it either on the river side or the land side. A cableway of the Lidgerwood type (Fig. 9) was purchased and started to work on the upper end of the Third District. The first cost of a cableway of this type erected and equipped is about $45,000. It has a clear span of 662 ft. The towers are of steel, 85 ft. and 45 ft. high respectively, and support between them a 2}4-in. cable. On this cable travels a carriage which car- ries a 3-yd. dragline bucket. Derricks are provided on each tower for handling the track. The crew of this machine consists of 1 foreman rigger; 1 op- erator; 1 rigger's helper; 1 engineman; 1 fireman; 1 signalman; 8 laborers; (trackmen) 3 on tail tower and 5 on head tower, 3 laborers (dressing levee), 3 teamsters (plowing, dressing levee, and hauling supplies). From April to December, inclusive, in 1915, 153,900 cu. yd. of material were placed at a cost of 15 ct. per cu. yd. Delays were caused in September and December by high water. Levee Building with an Oglesby Tower Dragline. Engineer- ing and Contracting, May 12, 1915, gives the following: The main tower (Fig. 10) consists of a timber frame, 78 ft. high of 10 x 14-in. timbers on a 24 x 27-ft. base. The tower is sup- ported on a platform of seven 12 x 16-in. timbers 40 ft. long laid on wheel trucks spaced 32 ft. The wheel trucks are each com- posed of four 20i4-in. double flange, iron wheels running between two 12 x 16-in. timbers 24 ft. long. Upon the platform are mounted three 60-in. drums and a pony drum operated by double 121/4-in. by 15-in. Flory engines and a 150-hp. locomotive boiler. The operator's platform is 26 ft. above the tower base. Control is secured through seven levers and six pedals connected with the drums by pipes to the platform. The dragline sheave may be DIKES AND LEVEES 1259 1260 HANDBOOK OF EARTH EXCAVATION raised and lowered to suit varying heights and slopes of levee. The slack cable and tail rope operate over sheaves at the .top of the tower. The cableway is attached within the tower to a throw wheel double block, the rope from which leads over the central drum. The tail tower consists of a platform 20x20 ft. laid on five 12 x 12-in. by 20-ft. timbers supported on two three-wheel trucks spaced 16 ft. The gallows frame is 24 ft. high and the counter- weight boom 24 ft. long. Timber . seats are used for both the gallows frame and the boom. The boom seat is slightly rounded to the segment of a circle having a cord of about 6 ft. and a mid- dle ordinate of about 8 in. This joint is unique and bears an im- portant part in facilitating the movement of the tail towers, as described later. A vertical boiler and second-hand hoisting engine are mounted on the platform of the tail tower. The counter- weight consists of a timber box filled with earth. This tail tower is a loose jointed structure and has an impor- tant function in absorbing shocks occasioned by sudden stoppage of the bucket. It acts as a safety valve in the operation of the machine. The dragline and slack line cables are \% in. in diameter and the tail rope is % in. diameter. These cables have handled 154,000 cu. yd. of earth up to the present time and very little wear is ap- parent. No trouble of any kind has been experienced with the cables. In this connection the sheave arrangement is worthy of note. Bucket. The bucket was designed by C. G. Oglesby and made in Memphis, Tenn. The average time required for a round trip of the bucket from the back of the borrow pit is 3 minutes. As a rule the bucket pushes about 1 cu. yd. of earth in front, some of which falls off and builds up the berm. The amount of earth moved in a trip varies from 5 to 9 cu. yd. The average bucket load of a day's run is probably 6 cu. yd. For dumping, the elevation of the dragline sheave has been so adjusted that the teeth of the dumped bucket follow naturally the face of the 1 to 3 levee slope. This facilitates the use of the bucket in dressing the levee face. The bucket is dragged over the earth already placed in the levee to the dumping point. The compaction resulting from the repeated passage of the loaded bucket, the average weight of which exceeds 15,000 lb., is an im- portant factor in securing a stable levee. When the earth is wet the three stage method of placing is employed as shown in Fig. 11. Ordinarily the earth is placed the full height for each runway. DIKES AND LEVEES 1261 Two men with shovels are employed, finishing and smoothing the earth placed in the levee. If the earth is quite wet when placed and drys out in clods, a Mormon scraper is used to advan- tage in smoothing. The costs given here are not representative of the cost of hand- ling earth with the Oglesby machine since they include the cost of developing the machine to its present state. The costs given, more- over, do not include accurate repair or construction costs on the machine or the contractors' overhead cost. These costs are, how- ever, estimated at $25 a day. The operating costs it is believed by Mr. Oglesby could be materially reduced by increasing the boiler capacity and thereby reducing the coal loss resulting from the use of forced draft on the present boiler and by using a 10-cu. yd. bucket. The amount of earth to be moved on the job does 31 *----^_^ 4' ^-^-^^ zi Fig. 11. Stage Method of Building Levee When Earth Is Wet. not, however, justify these changes. Table I gives the daily op- erating cost of the excavator. The machine has operated up to Apr. 20, 1915, a total of 1,914 hr. and has built 154,031 cu. yd. of compact levee, an average hourly output for the whole job of 80 cu. yd. The best day's work was on April 18, and amounted to 1,610 cu. yd. of compacted levee, a length of 70 ft. On that day the cost of building finished levee was approximately 8 ct. a cu. yd. It must be borne in mind when comparing the costs of this work with team work that the average haul for wheelers would be not less than 400 ft. The machine is essentially long haul, shallow pit type of excavator. The machine was erected early in 1914, and, after numerous de- lays incidental to the development of a pioneer machine, was well started Sept. 1, 1914. Work was interrupted by high water on the Mississippi for a month in 1915. On April 20, 1915, a total of 154,000 cu. yd. had been moved and it is estimated the job will be completed by Aug. 1, 1915. The daily (12-hr.) cost of operating the excavator was: 1 foreman at $150 a month, 20 days $ 7.50 1 runner at $150 a month, 20 days 7.50 3 trackmen at $2 6.00 1 fireman 3.00 1 tail tower engineman 3.00 1 tail tower helper 2.00 1262 HANDBOOK OF EARTH EXCAVATION 2 levee trimmers at $2.50 5.00 1 extra man 2.00 1 pump engineman 2.50 1 team and teamster 5.00 1 night watchman 2.50 Total daily labor cost $ 46.00 Fuel. 7 tons coal (on 3 boilers) at $7.75 54.25 Oil and waste 1.50 Total daily labor and fuel cost $101.75 Repairs, depreciation and overhead expenses esti- mated for normal conditions 24.00 Total daily operating cost $125.75 Output April 11-20, 100 hr. operated, compacted levee, cu. yd 8,754 Earth actually placed in levee, allowing 25% shrink- age per 12-hr, day, cu. yd 1,340 Approximate cost per cu. yd. compacted levee, ct 11.7 Approximate cost per cu. yd. earth moved (no shrink- age), ct Building Levees with a Hydraulic Dredge. In Engineering News, Oct. 29, 1914, appears the following by Jean M. Allen: Sand or gravel dredged by the hydraulic process is not carried entirely in suspension by the water in the discharge pipe, but the heavier material settles and flows along the bottom at a velocity much lower than the impelling water. This is specially true if the pipe line is long or the velocity of the discharge water is low. This action can be utilized to build embankments of as steep a slope as 1 on 1, directly from the discharge pipe. This is accomplished by what are called " shutter pipes," which are lengths of ordinary slip-joint discharge pipe, generally made of No. 10 to 14 sheet steel and in lengths of from 16 to 18 ft., with openings in the bottom. (See Fig. 12.) These openings are controlled by steel plates or shutters and may be opened or closed at will. A stretch of these pipes is laid on a trestle and the discharge pipe from the dredge is connected to them. When the shutters are opened the sand flows at about the con- sistency of thick mortar, building up into a steep embankment. The discharge pipe is continued beyond the shutter pipe in order to carry away the surplus water and avoid washing down the levee which has been built. The shutters should be spaced 3 to 4 ft. apart, and should be attached to the pipe with chain or wire, otherwise many will be dropped into the fill and lost. Many sizes and types of dredges have been used, with discharge pipes 12 to 20 in. in diameter, and the cost of the complete plant is from $15,000 to $100,000. Both steam and electrically driven dredges are being used. Some have revolving cutters or water jets to disintegrate the material, but many have neither appara- DIKES AND LEVEES 1263 tus. This depends on the compactness of the material to be ex- cavated. In general, any attempt to economize in first cost at the expense of construction or equipment of the dredge will be paid for dearly in subsequent breakdowns and loss of time. Mississippi and Missouri River Dredges. On these rivers, 12 and 15-in. dredges are used, due no doubt to the reluctance of the contractor to build an expensive plant for the small yardage of contracts offered. The total cost of a 12-in. plant, complete with pipe line, is be- tween $15,000 and $25,000, depending upon the class of machinery and the refinement of construction. Between 25,000 and 50,000 cu. yd. per month would be the probable output, depending upon ffcr shutter plate LpngitudincJ 1 Section Shutter Plate. Bottom Plan *<> tw Fig. 12. Bottom Discharge Gates for Shore Pipes of Hydraulic Dredge. the length of the pipe line, the layout of the work, river condi- tions and the skill of the operators. The dredge with 15-in. pump is built along the same lines as the 12-in., though frequently the pump is directly connected rather than belt driven. In either case, the engine should be compound, to save fuel. Between 250 and 300 hp. is required for a plant of this size, depending upon the conditions mentioned. An efficient engine for medium power is a cross-compound of either the hori- zontal or marine type. The boilers should have about 2,500 sq. ft. of heating surface. If surface condensers are installed, water- tube boilers may be used, otherwise the Mississippi River type is to be preferred. A donkey boiler should be provided for washing the main battery. A hoisting engine handles the suction pipe, but it is desirable to have a deck capstan with independent en- gines for handling the boat. The suction pipe is articulated at the end of the dredge either by a swivel elbow or merely by a length of suction hose, and is raised and lowered by tackle suspended from an A-frame over the bow. Its lower end is provided with a suction nozzle, consisting 1264 HANDBOOK OF EARTH EXCAVATION of a cone-shaped head with cross bars to prevent the entrance of large stones and pieces of wood that would clog the pump. The hull will be about 110x30x5 ft. The 15-in. dredge, complete with all equipment, will cost between $25,000 and $45,000 and its output will be from 60,000 to 125,000 cu. yd. per month. To at- tain the latter figure, the conditions must be very favorable and the dredge must be operated cpntinuously (24 hr. a day) and with very few delays. The maximum monthly output of which a dredge is capable is rarely attained in levee work, on account of the large percentage of time lost in shifting pipe, and it is of great importance that experienced men be employed, to reduce this loss to a minimum. As the shutter pipes have to be shifted ahead as each section of the levee is completed, it is advisable so to plan the work that operations can be conducted on two sections simultaneously. The main discharge pipe is provided with a Y-branch and gate valves so that the filling can progress on each section alternately, thus reducing the idle time of the dredge. If this is not possible, sometimes the levee is brought up to the full height but not to full width at the first operation, and then widened with the branch line while extending the main line. Some contractors use a discharge pipe of larger size than the pump and suction; for instance, an 18-in. discharge pipe for a 15-in. pump, with 15-in. suction pipe. The purpose is to save power by reducing the velocity of water in the line and thus the friction head pumped against. But it is the velocity rather than the quantity of the water that is instrumental in keeping in sus- pension and transporting such heavy material as coarse sand and gravel. Enlarging the discharge pipe reduces the velocity and causes the sand to settle until the cross-section is reduced and the velocity thus increased to a point where it will again carry the material. It is better practice to use a discharge pipe of the same size as the pump as far as it connects with the shutter pipe. There it may be enlarged, as it is desired that the sand should settle so that it may be discharged through the shutters. In a high- powered 20-in. dredge on the New York Barge Canal, difficulty was experienced in pumping gravel and small boulders through a long 20-in. discharge line, but upon replacing this with a 16-in. line the material was discharged with ease and the output greatly increased. Shields or slope-boards, consisting of plates of No. 16 steel about 10 ft. long and 18 in. wide, are frequently used to facilitate the formation of the desired slope. A number of these are in- serted, end to end, in the partly formed slope. They prevent DIKES AND LEVEES 1265 the sand from flowing downward until it fills to the top of the plates, when they are pulled out and moved further up the slope. The hydraulic construction of levees requires considerable skill. The suction-pipe operator must keep a steady and uniform flow of sand in the discharge pipe, and the pipe men must use judg- ment in opening and closing the shutters to build the embank- ment to the proper slope; closing some of them if the percentage of sand in the pipe decreases and opening enough of them to discharge water if the slopes need to be flattened out. The hand- ling of the slope boards also requires practice. With a good re- liable plant, properly designed to meet local conditions, some re- markable results have been obtained, not only in the low cost per yard but in the character and appearance of the fill. The monthly operating costs given in the accompanying table are typical for a 15-in. dredge on the Mississippi River: 1 foreman , $ 150 1 engineman 125 1 engineman 100 2 suction operators, at $100 200 2 oilers, at $60 120 2 firemen, at $70 140 2 coal passers, at $60 120 3 deck hands, at $60 180 1 levee foreman (day) 90 1 levee foreman (night) 70 10 levee laborers, at $60 600 26 Total labor cost per month $1,895 Coal (18 tons per day) 1,200 Supplies (rope, oil, packing) 150 Repairs and renewals 200 Office and overhead expenses 200 Insurance (fire and liability) 100 Interest and depreciation (2% on $35,000) 700 Total operating cost per month $4,445 This is for two 12-hr, shifts daily. The wages do not include subsistence. Assuming an output of 75,000 yd. per month the cost is about 6 ct. per yd. Construction of Levees by Hydraulic Dredges. D. L. Yarnell, in Engineering News, June 11, 1914, describes work on levees on the Mississippi River near Trempealeau, Wis., and in Henderson County, 111., as follows: Each of the dredges consisted of a hull 24x80x4^ ft., upon which were mounted a centrifugal pump having one 12-in. suc- tion pipe and a 14-in. discharge pipe, a 200-hp. engine, and a boiler nominally rated at 150 hp. The discharge pipe was car- ried from the dredge to the top of the levee by small towers mounted on 14 x 40-ft. barges. The power actually developed by 1266 HANDBOOK OP EARTH EXCAVATION the engine varied with the length of the discharge pipe, the height of delivery and the 1 character of the material pumped. The desired slopes were formed by means of steel boards about 18 in. wide and 10 ft. long, of No. 14-gage steel with angle-iron top, not too large or heavy to be easily moved by one man. The slope boards are placed at the intersection of the side slope with the natural slope of the end of the fill under construction. Sev- eral men equipped with shovels are necessary to distribute the material evenly and to move the slope boards ahead as the levee is built up. In the Trempealeau District, there were two separate levees constructed. The levees were built with material from the chan- nel excavated to divert Trempealeau River from near the foothills to Trempealeau Bay. The average width of the levee crown is between 8 and 10 ft., and the average height of embankment is probably 14 ft. The levees have slopes of 1 on 3 on the water side and 1 on 2 on the other, with banquette against the land side upon which is a roadway. The site for the levee was not cleared of vegetation and stumps were not grubbed out for the reason that during the greater part of the construction period, the bed of the levee was flooded. It was assumed that the method of construction so completely sealed the voids around the stumps that moisture enough will be retained and the air excluded to prevent decay. The total earthwork in the two levees and divert- ing channel is approximately 500,000 cu. yd., which was let at a contract price of 8.5 ct. The construction work was begun in May, 1912, and completed in October of the same year by the La- Crosse Dredging Co., two dredges being used. Part of the levees in Henderson County, 111., drainage districts Nos. 1 and 2 are being built by hydraulic dredges. The levee of District No. 2 is a reinforcement placed against the west side of the C., B. & Q. R. R. (Carthage Branch) embankment, carried about 3 ft. higher than the track. The easterly slope of the new fill is 1 on U/ 2 , and the slope on the water side is 1 on 2%. About 126,382 cu. yd. have been let at a contract price of 15.9 ct., 23,400 yd. at 20 ct., and there is an additional 5,900 yd. for which contract has not yet been let. On the District No. 1, two sections of the levee are to be constructed with a suction dredge. The total length of these two sections is 20,500 ft. ; the embank- ment is to have an 8-ft. crown and 1 on 3 slopes on both sides; the contract price is 11.25 ct. per cu. yd. The rest of the levee, incuding probably two to three times the amount of earth-work, with 6-ft. crown, 1 on 3 slope on the water side and 1 on 2 slope on the land side, is to be constructed with a dragline excavator at 12.1 ct. per cu. yd. The advertised earthwork, based on a 6-ft. DIKES AND LEVEES 1267 crown throughout the entire length and combined slopes of 1 on 5, was 821,400 cu. yd. At the time of the inspection, the levee being built was about 14 ft. high, and the top width was 2 to 3 ft. wider than the 8 ft. specified. The designed section of the levee at that point contains practically 26 cu. yd. to the linear foot, and the con- structed section about 27 cu. yd. On the day of the inspection, Aug. 23, the two 11-hr, shifts built 100 lin. ft. of completed levee, or 2,700 cu. yd. were actually placed. There were no delays for repairs, moving dredge, or any other reason. On this work a strip about 30 ft. wide in the base has been grubbed and ploughed, the entire base being cleared. The number of men usually em- ployed was about 14, and the fuel used about 5 tons of good Il- linois coal, in each shift. The average day's work will be con- siderably less than this, and to the cost of labor and fuel must be added that of dela3 7 s, repairs, depreciation of plant, prepara- tion of site, superintendence, and overhead charges. A 20-ft. head with about 600 to 800 ft. of discharge pipe is the maximum condition under which a plant developing only 200 hp. can operate; greater heights and distances may be overcome by a corresponding increase of power equipment. The dredge must always be in about 8 ft. of water to prevent air from being drawn into the suction pipe. A dredge of this type costs approximately $15,000, not including the discharge pipe, the barges, and other necessary appurtenances, which will add about $5,000, making the total first cost about $20,000 for a plant to build levees by this method. It would hardly pay to put such an outfit on a contract of less than 250,000 cu. yd. Building Levees in 111. by Hydraulic Dredging. Jean M. Allen, in Engineering and Contracting, Feb. 16, 1910, gives a description of the method of filling low areas at Cairo, 111. This work was particularly interesting because the material pumped into the fill by the hydraulic dredges was sand which is- not used for filling low places as often as is clay or alluvial mud. Furthermore, the Cairo plant was unique in that the flow of material through the very long pipe line from the dredge was accelerated by the use of a booster pump. The method used for building up the levee enclosing the dredged material was also unique. The tendency of the sand to settle in the bottom of the pipe permitted the building of levees having any desired slope, ranging from that assumed by moist sand to the slope of a semi-fluid. It was observed at Cairo that the gravel dumped from the openings nearest the pump was coarsest and that the material became finer as the distance it was carried increased. The method used in hydraulic fills of placing boards 1268 HANDBOOK OF EARTH EXCAVATION as retainers on the slope was here used until it was realized that as sand was less inclined than clay to hold moisture, boards were not required. The regulation of the gate openings con- trolled the solidity of the fill. Even where mud is used for fill- ing, sand might be efficiently employed to form retaining em- bankments if obtainable by dredging in sufficient quantities. Sand also settles much more quickly than does clay alone after being pumped. The addition of a certain amount of sand" to clay embankments formed by dredging or hydraulicking would cause a quicker settlement of the material and would likewise improve the character of the fill. Regarded as a hydraulic filling proposition some rather un- usual and difficult problems presented themselves. The extreme distance to which the material was pumped was something over 6,500 ft. and the greatest elevation to be overcome at extreme low water was about 38 ft. Extreme low water was about 5 ft. referred to zero on the government gage at this point and the city grade was 43 ft. referred to the same gage. As it was in- tended to use 12-in. pipe and as a velocity of water of at least 10 ft. per second had to be maintained to keep the heavy sand and gravel in suspension, a total friction and static head of about 300 ft. had to be overcome. There were very few data available on a plant of this kind. Some of the builders of standard dredging pumps declared that the proposed heads were excessive and declined to submit bids on the equipment. A somewhat similar plant found working in Kansas City, was carefully studied and much valuable informa- tion gained therefrom. The following was the plant eventually decided upon and in- stalled: A floating dredge was installed in the Mississippi River adjacent to the sand bar. It was connected to the bank by a pile trestle extending into the river a distance of 100 ft. and by a rigid pontoon line 160 ft. long connecting the boat with the trestle. Articulations at the connection of the trestle with the pontoons and of the pontoons with the bow of the boat enable the suction pipe, located at the stern of the boat, to pump sand from any point in the interior of a semicircle whose radius is 380 ft. On the boat was installed a 12-in. centrifugal dredging pump of a standard make with a 32-in. runner. This pump was belted to a 20 x 24-in. slide valve engine. Three " Mississippi River " boil- ers, each 44 in. in diameter and 22 ft. long, supply steam at a pressure of 140 Ib. To save time necessary to construct a hull for the dredge a river tow boat 141 ft. long, 26 ft. beam and 4^ ft. deep was secured and the dredging machinery placed upon it. The boat's original boilers, feed pumps and capstans were utilized DIKES AND LEVEES 1269 in the dredging equipment. The suction pipe passed over the stern of the boat and was raised and lowered by a small hoisting engine. In high water periods this suction pipe was about 50 ft. long. A shore pumping plant, or " booster " plant, was located just inside the levee at a distance of about 1,800 ft. from the boat. The pump and engine were duplicates of those on the boat. Steam was furnished by two standard tubular boilers 76 in. in diameter and 16 ft. long. The discharge pipe from the boat plant connects directly to the suction of the shore plant pump. Both boat and shore plant used the Mississippi River water for boiler feed and both plants ran non-condensing. The length of the pipe line from the shore plant to the dis- charge was about 1,300 ft. when the filling commenced and was increased to 4,400 ft. with the progress of the work. All pipe used except the suction and pontoon pipe was 12-in. spiral riveted pipe, asphalted. Nearly all the pipe was No. 12 gage, but on the end of the discharge line where the pipe required frequent handling and lightness was a prime consideration, some No. 14 and 16 gage is used. A private telephone line connected the boat, shore plant and end of discharge pipe, and by it the suction operator was kept con- stantly informed as to the percentage of solids carried in the water and is thus enabled to regulate the supply. The surplus water found its way to the river by means of the city sewers. The original estimates of the cost were somewhat exceeded and $42,000 was expended on the plant before it was. ready for opera- tion. Pump Wear. The plant was started late in the season of 1907. A number of difficulties developed after the plant had been in op- eration a short time. The most serious was the rapid wearing of the shells of the dredging pumps. These were of cast iron and not very thick and it was found that every 15,000 cu. yd. pumped required a new set of shells at both the boat and the shore plant. This extreme wear was due in part to the quality of the material handled. The Mississippi River sand is very coarse and sharp. The high speed at which the pump had to be driven caused the shells to cut out faster than most sand pumps. It was found that, at low water periods and when pumping to the most distant areas a peripheral speed of the runner of about 5,500 ft. per minute had to be maintained to produce the required velocity in the pipe. Considerable trouble was experienced with the pump shafts as they wore very fast m the siuffing boxes and finally broke. As the pumps were of the side suction type great trouble was ex- perienced in caring for the end thrust of the runner. 1270 HANDBOOK OF EARTH EXCAVATION A great deal of. time and money was spent in the endeavor to produce a pump more suitable for the work. Pumps with larger diameter runners, and with renewable liners in the shells were tried and at length a pump was evolved that gives very good sat- isfaction. The pumps finally used which were designed and built specially for this work, were of the double suction type to obvi- ate the end thrust. The runners were built up of steel casting and %-in. boiler plate and were 52 in. in diameter. The shaft was 6 in. in diameter. The shells were concentric with the shaft and are heavy steel castings. The inside dimensions were 6 ft. in diameter and 10 in. wide. The metal in the shells was 1^ in. thick on the sides and 2 in. thick on the circumference. These pumps gave excellent service. A pair of them pumped 80,000 cu. yd. of sand, and it was estimated that a pair of the steel shells would deliver 200,000 cu. yd. before wearing through. The 22-in. belts connecting the engines and pumps gave a great deal of trouble. Rubber and leather belts were tried, but none would stand the severe service. At last a wire rope drive was installed in both plants. This drive consisted of the ordi- nary grooved pulleys and ten parts of %-in. wire rope. Each strand of the wire was served with marlin which produced a very flexible rope. This transmission gave excellent service and caused no trouble since its installation. Average Output and Cost. The periods of unusually high and low water experienced the last two years proved a great handicap to the work. At the extreme low water, which lasted for two or three months in the fall of the year, the sand bar was entirely dry and the boat was aground and could not be moved to secure a supply of sand. Again at high water, which was sometimes 45 ft. above low water, the land outside the levee and the trestle work to which the pontoons connected was from 6 to 10 ft. under the water. The running ice which filled the river during January and February was dangerous. These conditions rendered it neces- sary to suspend operations for at least six months out of the twelve. The plant averaged about 30,000 cu. yd. per month when running, and, up to the beginning of 1910 about 340,000 cu. yd. were moved. A set of observations of the working conditions were taken December 4, 1909. BOAT Engine 132 R. P. M. Pump 352 R. P. M. Indicated horse power 321 Pump suction % . 15 in. vacuum Pump discharge 60 Ib. pressure Steam pressure, boiler 138 Ib. Coal consumption About 1 ton lump per hour DIKES AND LEVEES 1271 SHORE PLANT Engine 140 R. P. M. Pump 384 R. P. M. Indicated horse power 365 Pump suction 4 Ib. pressure Pump discharge 82 Ib. pressure Steam pressure, boiler 130 Ib. Coal consumption About 0.7 Ib. screenings per hour The velocity of the water was not determined accurately, but was about 10 ft. per second. The percentage of solids carried was also difficult to determine for the reason that a few hundred feet away from the pumps the sand settled to the bottom of the pipe, and while from 10% to 20% of the cross sectional area of the pipe may be filled with sand, this sand travels at a much slower velocity than the water. The average amount of solids delivered per hour was about 65 or 70 cu. yd. About 16 men were required on the day shift and about 14 on the night shift. The weekly pay roll amounted to about $500. An extract from the report of October, 1909, is an average per- formance and is as follows: Total yardage pumped 33,577.9 Total hours run 515 Yards per hour 65 Expenses Per cu. yd. Fuel $0.0482 Labor 0.0599 Repairs 0.0082 Oil 0.0022 Office and sundry 0.008 Total per cu. yd $0.1265 This statement makes no allowance for interest, depreciation nor insurance. The contract price on the above work was from 24 ct. to 30 ct. for the railroad work and from 28 ct. to 44 ct. for the city work the latter payable in bonds. Shutter Pipes. A feature of the work of interest was the method used in building the levees to confine the material within the desired areas. At first the levees were thrown up of earth by means of slip scrapers, but later they were built of sand directly from the pipes by what are termed " shutter " or " slide pipes." A number of lengths of the regular discharge pipe were provided with openings on the lower side about 3x4 in., the 4-in. dimen- sion being crosswise of the pipe. These openings were spaced about 3 ft. apart in the pipe and closed by suitable sliding plates of No. 8 sheet steel which work in grooved castings which bolt over the openings in the pipe. When one or more of these slides were opened the sand issuing from them was of the consistency of 1272 HANDBOOK OF EARTH EXCAVATION mortar and built up very steeply. It was possible with a little care in operation to build up the sand to a 1 to 1 slope on the outside of the fill. If the slope was too steep the slides were opened wider and some water allowed to escape which flattened down the slope to any extent desired. The end of the discharge pipe was continued some distance away so that the water there- from would not interfere with the levee building. In making the levees in this manner advantage was taken of the fact that the heavy sand in long pipe lines is not carried in suspension by the water, but moves along the bottom of the pipe, three or four inches deep, and at a much slower velocity than the water. The action is very much like waves, there being alter- nately high and low places, the higher material being continually removed and carried forward to a depression. This peculiar wave- like action of sand transported in water is dealt with in many U. S. Government Engineer reports and in Johnson's " Surveying." Sand Core Levees in California. In Engineering and Contract- ing, Apr. 29, 1914, R. G. Clifford describes the construction of a sand core levee in the Sacramento Valley, California, as follows: Economical construction of these extensive levees necessitates the use of the materials immediately at hand and these consist of a deep sand in the river bottom and stratified sedimentary de- posits of clayey silt along the banks. The average height of this 17.7 miles of river levee is 15 ft. and approximately 4,500,000 cu. yd. of material were necessary to construct a bank of sufficient stability to be absolutely safe under conditions of maximum flood. Most of the recent levee work has been done with large clam- shell dredges having 5 or 6 cu. yd. buckets, which pile the river sand up along the banks after clearing the timber and brush from the site. These sand banks are very slow in accumulating any growth and are thus left unprotected from scour and wave wash unless brush or tule mats are provided at considerable expense. A heavy growth of cotton wood, willow and black oak lines the river throughout its length and it was to take advantage of this natural protection to current and wave action that first sug- gested the use of a levee built with a suction dredge. The levee was located with its center line 150 ft. back from the natural river bank except where the distance was less than 800 ft. to the existing levees across the river when this minimum flood plane width was used. Retaining dikes, Fig. 13, are thrown up first by drag line ex- cavators mounted on trucks having 16 wheels running on two standard gage parallel tracks. The booms are 100 ft. in length, and 3y 2 and 4i yd. Bucyrus and Page buckets are employed in the varying material encountered. These drag lines backed down DIKES AND LEVEES 1273 the cleared right of way, digging a deep cut-off trench of suffi- cient size to furnish material for the two retaining dikes on each toe of the finished levee. The crown of these dikes was kept about 6 ft. below the finished top of the levee and was made 5 ft. wide with a natural slope of about 1% to 1. The total yardage in- Riverside Varies wifh Levee Ht Fig. 13. Cross-Section of Sand Core Levee Showing Sequence of Construction Operations. eluded in this drag line work for the river levee is 1,224,400 cu. yd. The operation of Drag Line No. 2, which did 60% of the work, is given in Table I. The cost of excavating this 743,056 cu. yd. of core trench ma- terial and placing it in the two dikes is divided as follows: Labor of operation $24,013 Fuel, 8,645 bbl. oil 8,645 Superintendence and engineering 2,800 Moving and erection at beginning 2,400 Repairs 11,900 Total $49,798 20% annual depreciation on $28,717 worth of equipment 5,743 Grand total (12 mo.) ^ $55,541 Cost per cu. yd $0.075 The efficiency of operation increased very materially after the crews became trained to handle this particular character of con- struction. TABLE I. OPERATION OF DRAGLINE EXCAVATOR (12 MOS.) Operating, hr 6,884 Digging, hr 5,507 Per cent, of time digging 80 Yardage moved 743,056 Cu. yd. per hr. digging 135 Cu. yd. per bbl. fuel oil 87 Cu. yd. per lin. ft ". 13 The best month's work was in Jan., 1913, when 120,128 cu. yd, were excavated in 744 operating hr. or 627 digging hr. 1274 HANDBOOK OF EARTH EXCAVATION The dredge had a hull 150 x 35 x 9 ft. in size, and a 20-in. pump driven by a 650-hp. triple expansion steam engine. Crude oil costing 85 ct. per bbl. was used for fuel. The limits of dig- ging were 7 ft. minimum and 36 ft. maximum, although the average was 18 to 32 ft. The lift was from 20 to 30 ft. with 1,400 ft. average length of pipe used. The crew consisted of 3 levermen, 3 enginemen, 2 firemen, 2 deck hands, all on the dredge, beside a shore gang of 34 men total for the two 12-hr, shifts. The levermen worked 6 hr. on and 12 hr. off, making an average of 8 hr. per day. The dredge worked downstream so as not to require outside mo- tive power for moving. The pipe was extended across the space between the river and levee center, and the distributing " pocket pipe" was supported on bents for an average distance of 700 ft. on a slight down grade along the center of the levee. Tem- porary wooden baffles kept the stream at the discharge end to- ward the center of the levee to prevent washing of the side dikes. The pockets are merely openings in the bottom of the pipe, opened or closed as desired by means of simple sliding gates operated by the attendant. The sand drains itself readily and builds up on slopes of from 1 on 10 to 1 on 4, depending on the fineness of the sand and the amount of silt present. The operation of the suc- tion dredge for the 2,053,509 cu. yd. handled to date is given in Table II. The cost of placing .this 2,053,509 cu. yd. of sand core is di- vided as follows: Labor of operation $ 53,054 Fuel, 20,436 Ib. 20,436 Superintendence and engineering 7,117 Repairs 27,727 Total $108,334 20% yearly depreciation on $105,300, cost of outfit.... 28,100 Grand total (16 mo.) $136,434 Cost per cu. yd $0.067 Since there were 13 cu. yd. per lineal ft. of drag line work against 35 cu. yd. of suction dredge work, the average cost of each cubic yard of levee untrimmed would be $0.07, including the as- sumed 20% depreciation charge on equipment. This cost in- cluded the plowing of furrows parallel to the core trench under- neath the side dikes to further prevent percolation between the original ground surface and the levee. To compare with a levee built by a clam shell dredge, the side slopes being the same but with no core trench excavated, the cost of the 13 cu. yd. of dragline work would have to be added to the DIKES AND LEVEES 1275 cost of the suction dredge yardage and the unit price would be $0.094 instead of $0.07. The justification for this additional expenditure is found in the efficacy of the earth blanket on the levee for furnishing a ready foothold for shrub and grass growth and the advantage of the core trench in breaking up the line of percolation and doing away with danger of the levee sliding on its base. It is also evident that to take advantage of the protection afforded by the natural growth along the river it was necessary to use the hydraulic fill type of levee, which in turn necessitated the use of the dikes. The presence of the sand in the core is the only certain way of preventing dangerous burrowing by gophers and other small ani- mals. In addition to the above levee cost there is a charge for pulling up the sediment in the dikes so as to cover the levee faces, as shown in Fig. 13. This covering sods readily and is soon com- paratively water tight, while the growth starting on it without delay aids greatly against wave wash. Little of this trimming has yet been done, but so far has cost about $3,000 per mile, or about $0.012 per cu. yd. of material in the levee, the work being done by teams. Since a road 24 ft. wide was to be built on the top of this levee, most of this trimming cost would apply to any form of levee constructed. TABLE II. OPERATION OF HYDRAULIC DREDGE (10 MO.) Operating, hr 10,730 Pumping time, hr 6,362 Per cent, of time pumping 59 Yardage moved 2,053,509 Cu. yd. per hr. pumping 323 Cu. yd. per lin. ft. 35 Cu. yd. per bbl. fuel oil 100 Bibliography. " Relief from Floods," John W. Alvord and Charles B. Burdick ; " The Improvement of Rivers," B, F. Thomas and D. A. Watt. " Standard Levee Sections," H. St. L. Coppee", Trans. Am. 800. C. E., Vol. 39, 1898. CHAPTER XXII SLIPS AND SLIDES General Discussion. An English author, John Newman, has written a book on the subject of " Earthwork Slips and Subsi- dences Upon Public Works." He cites some fifty " causes " for slides in cuts and embankments, but nearly all of them are merely varieties of one cause, namely the saturation of earth with water. The term " slip " is perhaps preferably applied to relatively small movements of earth ; and the term " slide," to relatively large movements, such as " land slides." Increasing the unit pressure on earth often increases the coef- ficient of friction. Whether this is universally true, is yet to be shown. But if it is universal, increasing the load on earth will increase the angle of repose. More tests on the coefficient of friction of different earths under varying unit pressures are badly needed. Lubricating earth with water decreases the coef- ficient of friction and reduces the angle of repose. The jarring of passing trains reduces the coefficient of sliding friction of earth upon earth and is the cause of some slips. High embankments built upon side hills in a clayey country often cause extensive slides of the underlying earth, and settle- ments of the embankment. Where experience has shown that such slides are to be expected, tile drains may be used to advan- tage in the site of the proposed embankment. Often there is no way of predicting a slide, and when it begins it is too late to do any draining of the subsoil. The fill has then to be carried up until the slipping stops of its own accord. An engineer may find upon examination that the real source of trouble lies in the damming back of water by the new embank- ment, which water by soaking into the subsoil so reduces the co- efficient of sliding friction as to cause the slip. In that case the remedy is obviously drainage ditches along the upper toe of the embankment, leading to a culvert. It would be a waste of words to attempt to outline all pos- sible methods of getting rid of water. In many cases it is im- possible, with reasonable expense, or even with unreasonable ex- pense, to get rid of the water that saturates and lubricates the subsoil. If embankments are to be built upon soft swampy muck, a compression of that muck is inevitable. The engineer should endeavor to secure a uniform distribution of the earth load so as to secure uniform settlement. This uniform loading he should have during construction as well as afterward. That is he should build the embankment up in horizontal layers not by end dump- ing if he can; for a concentrated load will simply push the 1276 SLIPS AND SLIDES 1277 muck out from under the load and not compress it. If it is im- practicable to build up in uniform layers, then it may pay to build a log or brush mattress upon which to dump the earth. The author has read very many accounts of the building of such mattresses written by those who seemed to think that in some way the mattress served to buoy up or float the finished embank- ment. As a matter of fact these mattresses ordinarily serve but one useful purpose. They secure an even distribution of the earth load during the construction of the embankment, and so prevent the soft muck from being pushed out from beneath the embank- ment. In very bad- cases a close line of sheet piling along each toe of a proposed embankment may be used instead of the mat- tress, for it must be remembered that the lateral escape of the subsoil muck is what is to be prevented if possible. It is obvious from the preceding discussion that in building an embankment the engineer should avoid dumping a mass of marl or soft clay in such a way that subsequent water saturation of it will cause a slip. Many marls are wholly unfit to form an em- bankment, and if a pocket of such marl is encountered in exca- vation it should be wasted. Clay, as is well known, shrinks some 5% when thoroughly sun dried, thus opening cracks or crevices through which water may gain access to the material below. A sod covering or a foot or so of sand covering over clay that becomes treacherous in this way will keep it from drying out. The Cause and Cure of Slides. George L. Dillman in a dis- cussion of a paper by D. D. Clarke, Trans. Am. Soc. C. E., Dec., 1918, gives tne following: Water lubricates and lessens friction. Water accumulates a head, and forces itself into and through otherwise impermeable material, thus extending the lubrication; but the greatest effect of water is from its pressure. It acts like millions of jack- screws, under and back of the slide, to produce motion. The film of water back of and under the slide has only to be thick enough to be continuous in order to transmit the pressure of its whole head in this manner. We have articles on the pressure of water under dams. A slide is a dam, in all essential features, until motion begins. Then, fortunately, the continuity of the water film is broken. At the instant the continuity is sufficiently broken, motion ceases. Then, if conditions are right, the inflow of water increases the continuity of the film, ..flows into the cracks, and motion again begins. A slide is frequently a number of dams, according to different planes of motion, any one of which may move. It matters not 1278 HANDBOOK OP EARTH EXCAVATION how saturated is the mass above the bottom of the slide, the analysis of bottom pressures and effects is not changed thereby. Although slides of some extent offer at first varying evidence, crumpling at the toe, upheaval in places, subsidence at the head, and lateral motion in varying degrees, they can all be traced to one phenomenon by proper analysis. There is frequently a swampy place at the head, sometimes attaining the dignity of a lake. There are usually springs at the toe, frequently also along its trace on the surface. These may develop by erosion into gulches which hide the cracks, the crumpling, and other ev- idences of motion. There is no need to enlarge on the cause of slides. Every fact in evidence can be traced directly to water, principally to its pressure. Sometimes, the surface can be drained sufficiently to effect a cure. Surface drainage will always help; but surface drainage is often difficult, especially after motion has developed a cracked wart-like surface, as this tends to hold rainfall and guide it to the surface of motion, or several surfaces of motion. Sub-drainage, which will kill the water pressure, is infallible. There never has been a slide that could not be cured in this way. There are cases where the expense is not warranted. There are cases where the whole slide can be sluiced away. There are also cases where the motion is so slow, or its effect so small, that the removal of the material as it comes, or not removing it at all, is the best answer. Incidentally, removal is drainage. Subsidence at the head of the slide tends to the formation of swamps and lakes, which, in turn, supply the water to fill the cracks, to form the pressure, to produce motion, to make more subsidence, and so on in a never-ending cycle. The interruption of this cycle is most certainly accomplished by killing the head of water acting on the surface of motion. Draining the swamps and lakes will help. At Panama one enthusiast proposed con- creting the whole surface of the slide to prevent the ingress of water. This might do, if there were not probably some subter- ranean supply of water, possibly with a great head, that would not keep out. Such construction might be an actual hindrance, instead of a help, and might serve to hold the water and increase, instead of decrease, the head. In some cases increasing the resistance to motion has been tried, by masonry and wooden bulkheads. These have been ef- fective where it only needed another " straw," but have gen- erally been disastrous. Drainage by perforating the bulkhead is taught as a rudiment in retaining walls. Far apart as they may seem, there is much similarity in SLIPS AND SLIDES 1279 glides, retaining walls, and dams. The analysis is nearly identi- cal, gravity, friction, and hydrostatic pressure. Sub-drainage will cure the slide, is necessary to the stability of the wall, and increases the safety of the dam. [In the author's opinion, Mr. Dillman is wrong in attributing slides mainly to water pressure. Water in clayey earth de- creases the coefficient of friction, so that sliding may occur without any change in pressure.] A Landslide at Mount Vernon. N. H. Darton, in Engineering News, Feb. 25, 1915, gives the following: Mount Vernon is situated on a bluff about 100 ft. high, fronting on the Potomac River. In Washington's time extensive land slides occurred on the front of the bluff, and a few years ago evidence was dis- covered that another slide was beginning. The movement was extending so far as to threaten the broad lawn in front of the ' - Fig. 1. Section Through Mount Vernon Bluff mansion itself. A small drainage tunnel was started in the bottom of the sandstone stratum and was driven back from the river front a distance of some 200 ft. From this drainage tunnel a considerable flow of water at once started and con- tinued for several months. At the end of that time the flow gradually diminished and now remains of moderate amount but practically constant. The draining of the overlying strata has apparently been so thorough that they are now able to sustain the load upon them without further movement. A masonry wall along the river at the water's edge prevents further under- cutting by the waves. An Extensive Earth Slip near Hudson, N. Y. Engineering News, Aug. 12, 1915, gives the following: The slip affected an area of 15 acres belonging to the Knickerbocker Portland Cement Co., on Claverack Creek. The first visible incident in the disturbance was the movement of a section of earth 50 ft. wide by at least 30 ft. deep and 200 ft. long, about 200 ft. 1280 HANDBOOK OF EARTH EXCAVATION southeast of the power house, and this section toppled over into the creek flowing 120 ft. east of the power house. This slide was followed immediately by others in ever-lengthening arcs, until a huge storage pile of crushed traprock was under- mined. The pile then sank 20 to 25 ft. over its area (160 ft. in diameter). This sinking caused the settlement and destruc- tion of the coal trestle and power house, in the order men- tioned. The disturbance extends over 15 acres of ground. The creek was pushed from 40 to 200 ft. out of its original course and its channel was dammed so that a new channel had to be blasted almost immediately to prevent the flooding of the plant. The water in the Claverack is from 6 to 8 ft. in depth. The entire earth movement was over in 2} min. The total damage will probably reach $250,000. The buildings of the company were on flat footings with no piling. The soil is the blue clay common to the Hudson Valley. The general slope is toward Claverack Creek (30 ft. wide) which bounds the company's property on the east, the water level being about 15 ft. below that of the property. The slope is about 1 on 2. The nature of the slippage indicates that water seeping through cracks at the foot of the bank caused a section of the bank to cave in, and this started a succession of similar movements, each farther away from the creek than its predecessor. Whether a lateral flowing of the clay subsoil under the heavy superin- cumbent load had anything to do with the caving cannot be de- termined. Land Slides at Bulls Bridge Hydro-electric Plant. Charles R. Harte, in Engineering Record, May 27, 1916, gives the fol- lowing: Water passing through the power house is carried through a long canal from the reservoir to the forebay. This canal follows a hillside, the easterly side in cut and the west- erly side in fill. Slides developed in the hill side that threat- ened to fill and destroy the canal. In 1907 an area about 100 ft. wide, extending 200 ft. up the hill, pulled forward several feet in as many hours, opening, at the top, a crack 3 or 4 in. wide, while the surface dropped nearly a foot. The entire affected area showed cracks parallel to the canal, far apart at the top but closer together toward the lower end, where the ground looked like a plowed field, and was 2 or 3 ft. above its original level. At the face the top overhung the base, and continually dropped down masses of a cubic yard or so. Under the direction of E. H. McHenry, then engineering vice- president of the properties, the slide was attacked from the SLIPS AND SLIDES 1281 front. The material, a hardpan with streaks of greasy clay of various colors, was so saturated that when touched it " melted " and flowed, but in a very short time the face was sufficiently drained to act as an abutment. The ditches were then pushed to the end of the movement, which had apparently extended 10 or 12 ft. below the surface, and no further trouble was ex-- perienced. Four years later an area of 7 acres immediately south of the first slide dropped about 4 ft. vertically, and moved forward, open- ing up a main crack about a foot wide and 30 ft. deep at the upper edge, 300 ft. from the canal. A series of smaller cracks appeared between, while the base, some 20 to 40 ft. high at the point, became saturated, bulged outward and dropped consid- erable material on the berm, which was between it and the water. Following the same general plan as in the case of the first slide, the face was " bled " by a series of ditches driven into it, a cut-off ditch was dug outside the limits of the movement to trap off all surface water, and, at the point of maximum dis- turbance, an exploration shaft was sunk some 25 ft., where a sliding plane of 3 ft. of clay was found. On this a drift was pushed 25 ft. up the hill to rock and 100 ft. down the hill to the base of the canal bank. A second drift was started at the bank face, 100 ft. north of the first, and a little above the canal level. This was driven in a northwesterly direction 80 ft. to the rock, and had a rising grade from the bank of about 2%. Thirty feet from the mouth a lateral was run nearly to the exploration shaft, and from near the end of the main drift another lateral was run north- westerly 240 ft., with two short branches eastward to rock. Comparatively little water was intercepted, but the behavior of the slide indicated that the small quantity found was the cause of the trouble. Apparently it had accumulated along the rock until the head was sufficient to start the mass, but this movement largely increased the size of the cavity, and some little time elapsed before the head was again sufficient to cause a succession of moves. The drifts were timbered with local chestnut, at least 8 in. in diameter for the sets, and 3-in. plank for the sides and roof. A bulkhead was maintained at the face throughout, and fre- quently the work was stopped for a day or so to drain off an unusually wet section. The advances were made by driving the roof and the top side plank, removing the top board of the bulk- head, excavating to the ends of the roof and side boards just driven, and setting the top of the next bulkhead. 1282 HANDBOOK OF EARTH EXCAVATION It was expected that the drifts would have to explore the en- tire line of the break, and future developments may necessitate such a course, but so far it would appear that the work already done has been entirely successful in anchoring the area, although less than ha'lf has been explored. There is evidently a series of planes of sliding, but, between the surface drains and the drifts, enough water has been intercepted to protect the planes below. Preventing Slides on the Chicago Canal. In a report of the engineers of the Chicago Drainage District, quoted in Engineer- ing and Contracting, May 27, 1914, slides developing on the side of the Calumet-Sag Channel are discussed. Three types of sliding ground have been encountered as fol- Fig. 2. Slope Paving, North Shore Channel, Chicago Drainage Canal. lows: (1) Structural breaks resulting from inability of a layer of drift to hold the weight of the overhead bank. , (2) Normal or gravity slides. ( 3 ) Surface erosion. Structural breaks occur at points where a layer of shale upon exposure to the atmosphere disintegrates and crumbles. A crack or fissure then develops in the bank, sometimes at a distance of 200 to 300 ft. from the channel center line and this crack gradu- ally widens and deepens as the bank moves slowly into the chan- nel. Instead of a layer of shale, the prime cause may be a peat stratum, or it may be a soft, silty or unstable clay. The normal or gravity slide results from the movement of the overhead bank upon a slippery layer of clay or other material, the line of stratification of which is clearly defined. It is due almost entirely to an excavated slope steeper than the angle of repose of the particular formation then being excavated, and in many cases has been further aggravated by the superimposing on the berm SLIPS AND SLIDES 1283 heavy spoil banks at a comparatively small distance from the slope. Surface erosion is a gradual sloughing of the surface of the slopes due to the weathering action of the elements. In addition to rain and wave action, the action of frost is a contributing cause of slides of this character. The freezing and thawing of the bank tends furt-her to aggravate the sloughing of the sur- face of the slopes, so that the sowing of shallow rooted grasses and like vegetation is not in all cases a sufficient preventive means. Water Surface J^T" f^'- Fig. 3. Slope Paving Calumet Sag Branch Chicago Drainage Canal. Rip-rap on a 12-in. layer of crushed stone or gravel is used with success to prevent surface erosion and even slides but at times has to be held in place with piles. Where rip-rap paving can be placed before water is turned into the channel it is better to carry the slope paving to a solid foundation. The Great Slides at Panama Canal. According to General Goethals these slides were of two kinds. One is the ship-launch- ing type, where a natural slip-plane exists on which the super- incumbent mass begins to slide under critical conditions of lu- brication. This is slow moving and may be very large and exert enormous pressure down hill. The Cucaracha slide was of this type. The other class of slip is the plastic flow kind, where a clay-like soil becomes suddenly plastic or semi-liquid under cer- tain conditions of moisture and pressure. The Culebra slides were of the plastic flow type. The magnitude of the slides at Panama precluded the possi- bility of stopping them with piles. Drainage would have been very costly, and, due to the excessive rain fall, possibly not effec- tive. Nothing could be done but remove the sliding material as it reached the canal prism. This has been done, and now that all the sliding ground has been removed the remaining banks appear to be stable. The volume of these slides was enormous having reached about 50,000,000 cu. yd. by Dec. 30, 1915. These 1284 HANDBOOK OF EARTH EXCAVATION unexpected slides added greatly to the estimated cost of the canal. A Remarkable Landslide at Portland, Oregon. D. D. Clarke, in two papers before the Am. Soc. C. E., Trans. Am. Soc. C. E., Vols. LIII and LXXXII, discusses the treatment of this slide. During 1894 two small reservoirs were constructed for the city of Portland. During their construction a slight movement of adjacent land was noticed. This movement increased in size so as to affect the reservoirs as soon as they were first filled. The reservoirs were immediately emptied and were out of use for ten years. Small shafts (22) and wash borings (33) were used to study the movement of the slide for a period of years. The dimen- sions of the moving ground were at length determined to be ap- proximately 1,700 ft. from east to west, and 1,100 ft. from north to south along the reservoir front an area of approximately 2914 acres the depth ranging from 46 to 112 ft., the average being 77.8 ft. The approximate volume was 3,400,000 cu. 'yd., and the approximate weight 4,600,000 tons. The borings and open shafts revealed the presence of a thin seam of blue clay along the surface of the bed-rock, with nu- merous water pockets in immediate connection therewith, several of the underground water pockets having considerable volume. Two of the largest of these water pockets were drained with pumps (the total pumpage aggregating several million gallons) with a marked deterrent effect on the movement of the slide, as indicated by the periodical instrumental surveys. Comparisons of Weather Bureau records of precipitation with the monthly movement of the slide indicated a close relationship between the two if it did not offer absolute proof that the rate of movement of the slide depended on the volume of the rain- fall during any series of months. After a study of all the observed conditions it became evident that the required remedy was drainage. Accordingly a total of 2,507 lin. ft. of drainage tunnels, with timber supports, was con- structed between June, 1900, and December, 1901, at a total cost of $14,161, or an average cost of $5.65 per lin. ft. for materials and labor. The results secured by the construction of these drains were considered very satisfactory, and for a time it appeared as if the slide problem had been fully solved. The volume of drainage from the tunnels was carefully observed for the 2 years following their completion, and was found to range from 10,000 to 15,000 gal. per day in summer, and from 25,000 to 75,000 gal. per day in winter; and at the end of 2 years it was SLIPS AND SLIDES 1285 decided that the drains were doing effective work and that it would be safe to proceed at once with the work of reservoir re- pairs. During March, 1904, immediately following the adoption of a plan for tunnel and reservoir repairs, it was noted that there had been an accelerated movement of the slide. There had been un- usual rainfall during the preceding 4 months, amounting to 27% more than the average for the same period during the past 21 years. To remedy this, the construction of supplemental drain tunnels was started early in 1904 and finished in 1906. In constructing tunnels the excavated material was hauled from the heading to the nearest shaft in narrow gage cars, which were then hoisted to the surface and dumped. Only a small force was employed on this work, one or two crews at different points, sometimes with two shifts per day, each crew consisting of: One tunnel man, at $3.00 per 10-hr, day; two helpers and one or two top men at $2.25 per 10-hr, day, each; and one hoisting en- gineman. The timber supports were framed by a man especially detailed for that work. A total of 4,021 lin. ft. of new tunnel was built between April, 1904, and August, 1906, at a total cost of $26,896, exclusive of engineering and superintendence, or an average of $6.69 per lin. ft., as compared with $5.65 per lin: ft. for work of a similar character completed in 1900-01. This increase in cost was due largely to the advance in the prices of material and labor during the intervening period. In 1901 outside laborers were paid $2.00 per day of 10 hr., and tunnel men $2.25 and $3.00 per day; and timber cost $8.50 per 1,000 ft. b. m., delivered. In 1904 and 1905 the same rate per diem was paid for labor, but the working hours were reduced from 10 to 8. This is equivalent to an ad- vance of 25% in the cost of labor; at the same time an equal or greater advance had taken place in the price of timber and other construction materials. The 4,021 ft. of new tunnels added to the length originally constructed gives 6,528 lin. ft. in the complete drainage system. The material encountered in the tunnel extension work was chiefly yellow .clay, intermixed with fragments of basalt. No large pockets of water were discovered, and in that respect the work did not accomplish all that was anticipated, but the ag- gregate volume of drainage from all the branches has been large, ranging from 18,000 to 108,000 gal. per day during some years, the quantity depending on the season of the year and the at- tendant rainfall. During recent years the volume of this drain- age has been somewhat less than noted above. 1286 HANDBOOK OF EARTH EXCAVATION Concrete Tunnel Culvert. It was realized that the timber sup- ports would soon decay. A study was made to determine the best method of lining the drains so as to insure permanency. OFTAfLS OF DRAINAGE TUNNC.L CAR AND HOIST. , Eining 2"x 8" Dning -3'2- x8 Rail 2 x 3" Footplank l"xl2" _EL j B Beam 2x6" J To contain 4.37 cu. ft. or 480 Ibs. 1 2'x 3 7 Knn ll = Joistifxl" !! J L ELEVATION OF CAGE AND CAR 6"x 8x 5'l" -3* ^jGuide timbers^ / " Waterway END VIEW PLAN OF SHAFT AND CAGE Fig. 4. Timbering Details, Portland Drainage Tunnels. The scheme adopted was well suited to this class of work. A circular concrete conduit was built in the tunnels, the base and sides of which were constructed as a monolith of the dimensions shown in Fig. 5. SLIPS AND SLIDES 1287 The advantages of this method of construction were two fold: First the distance between the side walls permitted a man to move freely and push a car with a narrow body. All construction SECTION OF TUNNEL SHOWING POSITION OF CONDUIT CONDUIT AT SHAFT PLAN ADOPTED FOR CONCRETE CONDUIT IN DRAINAGE TUNNELS UNDER SLIDING LAND TRACT WEST OF CITY PARK RESERVOIRS (1904) Fig. 5. Plan Adopted for Concrete Conduit in Drainage Tunnels Under Portland Landslide materials were transported from the foot of the nearest shaft in cars running on a narrow gage track laid on the tunnel sills, pr on the sewer invert after it had been built. The material for 1288 HANDBOOK OF EARTH EXCAVATION back filling behind the side-walls and over the top of the sewer was hauled in the same manner. Second, this style of construction made it possible to cast the arch blocks a sufficient time in advance to permit them to become thoroughly seasoned before being put in place, and consequently the work of back filling was not delayed while waiting for the setting of the arch and the removal of its supports. The diameter of the conduit was fixed at 28 in., that being the minimum size which would admit of comfortable inspection from end to end by a man of small or medium stature. Of 22 shafts originally excavated, 7 at suitable points, were permanently lined with concrete; the others were filled with earth on the completion of the tunnel work. In placing the arch blocks in position, the ends were cemented to the side-walls, but no attempt was made to close the crevices between the blocks at the crown of the arch. This space of, say, % in. in width for every foot in length of the conduit, was left open so as to admit any seepage water which might percolate into the tunnel and thence to the top of the conduit. At intervals of about 50 ft. a cut-off wall of concrete, 6 in. thick and 18 in. high, was built across the tunnel from side to side. These walls were deep enough and of sufficient length to cut off any flow of water along the outside of the sewer walls. The water is conducted into the conduit through a 3-in. opening left near the bottom of the invert at the up-hill side o each cut- off wall. At each side of the conduit a line of 3-in. drain tile was laid, connecting with the opening in the conduit at intervals of 50 ft., this opening being a few inches above the invert. The concrete materials used in the work were furnished by the contractor. Mixing and laying of the concrete were done by day labor under the Department foreman. The tunnel foremen were paid $3.00 per day, and other inside labor $2.25 per day. De- tailed cost kept during the period from June 1, 1904, to June 1, 1905, showed that 2,746 lin. ft. were completed at an average cost of $3.20 per lin. ft. for the materials and labor of constructing the conduit and back filling the tunnel. Treatment of Railway Slides. An abstract of a report by the Roadway Committee of the American Railway Engineering and Maintenance-of-Way Association was published in Engineering Xeivs, Dec. 10, 1908, from which the following is taken: Slides on railroad right-of-way may be classified as follows: ( 1 ) Slips of material on the sides of the embankment away from the road bed; (2) slips of portions of the cut toward the road bed; (3) general slides of the land. SLIPS AND SLIDES 1289 Slides of embankments are endless in variety and magnitude. They always occur in wet weather. The earth becomes surcharged with water, which increases its weight and at the same time les- sens its cohesion. The slide starts on a plane of rupture that is usually curved. The cure of slides in most cases is surface and subterranean drainage, which is often difficult and costly. The driving of piles in both embankment and excavation to hold masses of earth is often resorted to. This is never more than a temporary expedient, and is advisable only in special cases. Retaining walls at the foot of a slope may sometimes be neces- sary where right of way is restricted. But in the open country in nearly all cases where the ground can be obtained, the flatten- ing of the slope -is the most economical, the most efficient and per- manent method of treatment. The lobe at lower end of a slide often gives a good point of support or foothold for the filling used in restoring the roadbed. In embankment slides, the roadbed can be restored after it is dried out in a measure, by filling in with suitable material. Usually the steam shovel will be the best method to use. The way to get rid of slides in cuts, is to take them out by the cheapest and speediest way possible. Only in rare instances are other methods effective. Piling a Sliding Railway Cut. Engineering News, Apr. 30, 1918, gives the following: The railroad has at the point in ques- tion a double track on a curve of 2} (with 7 in. elevation) at the foot of a cut about 40 ft. deep in sloping or sidehill ground. The material is a wet yellow clay, and lies on a stratum of shale or hardpan. Water soaking through the clay mass gives a smooth and slippery or lubricated surface to the shale, and upon this the clay slides. Near the top of the cut is a public highway known as the Homestead Road. In January, 1906, considerable trouble was experienced, and a number of teams were employed to keep the road passable by filling in from the top the earth that was settling away towards the cut. In the spring, two rows of piles were driven along the lower side of the original line of the road and two rows of piles were also driven at the toe of the slope. The rows were 4 ft. apart, and the piles also 4 ft. apart, the rows being staggered. The piles were driven with a 2,800-lb. hammer, and were driven as far as possible into the substratum of shale, the penetration being generally about 6 ft. A layer of brush was filled between the two upper rows of piles, and this was covered with earth to a level about 2 ft. below that of the road. The road was then back- filled to the original line and covered with broken stone. No 1200 HANDBOOK OF EARTH EXCAVATION brush filling or other work was done at the lower row of piles. There are over 900 piles in these rows. Two French drains about 3 ft. wide were then built up the slope, being excavated into the shale and filled with about 4 ft. of loose rock. These were very expensive. There has been no apparent movement of either of the double rows of piling, or of the slide, since this work was done, and the work seems to have accomplished its purpose. Preventing Slips on Railways. Engineering News, Mar. 16, 1916, comments upon the success attained by the Missouri, Kan- sas and Texas Ry. in maintaining uninterrupted service in the Mississippi Valley during periods of record floods. A summary of the chief engineer's instructions for slip prevention is given. A common cause of slips in embankment is illustrated in 1, Fig. 6, where the fill has been widened without properly stepping the old slopes. This new fill of impervious material is often placed in such a way that the shoulders of the fill are higher than the old subgrade, forming pockets or troughs that retain water and cause soft spots in the track. Care should be taken to prevent this by removing the ballast from eroded or settled parts of roadbed and bringing the roadbed to grade with new material. The slopes of the old fill should be plowed before adding new material. The same precautions apply to roadbeds widened for additional tracks and to widening roadbeds in fills. Two examples of the effects of faulty drainage in widened clay embankments are shown in 2 and 3, Fig. 6. Transverse stone-filled trenches would have prevented these slips. In cuts, when a soft spot does not extend to a great depth and the cut is shallow, it is economical to widen the cut, lower the side ditch to a depth below the lowest pocket and drain the roadbed into the ditch by means of a stone-filled trench or a tile drain (see 4). When soft spots have extended too deep to be economically drained by deepening the surface ditches, they should be drained by tiling laid parallel to the track and below the lowest part of the soft spot (see 5 and 6). In a cut where there is seepage from both sides, intercepting drains should be constructed on both sides of the track (7) ; but if the seepage is from one side only, a single drain should be on that side. Where there is probability of water from a wet cut entering an adjoining embankment, a tile drain or a stone-filled trench should be constructed across the roadbed near the end of the cut, to intercept the flow (8). 9 and 10 represent typical conditions of pocket formation in SLIPS AND SLIDES 1291 cuts and show the way drains should be laid to take care of such formations. 11 gives in detail the method of laying and back filling tile Improper Method Proper Method Stone-filled Trench or Tile^ Wet C Ditch lowered to a Depth ....... , below Bottom of soft Spot Ti/ec/osed~ ' ,n Motion La f en ,i Drain-'' Engine Cmrtrs' 1 6 Excavation Embankment Backfill to green Shale, or impervious Material, well packed- > Drain /f t1ard burned or No ? Bell-end Drain Tile, not /tss -than 6" 11 m Diameter Fig. 6. Subdraining Roadbed to Prevent Slips. drains in cuts. Notice that these drains are for subsurface water and are not intended to take the place of the side ditches. Some general points to be borne in mind follow: Determine 1292 HANDBOOK OF EARTH EXCAVATION the depth of water in the pockets by digging a hole. Subdrains must always be laid below wet clay or below the lowest point in the pockets. If they are not so laid, they will not drain the pocket and will soon be displaced by slips. Trenches should be made as narrow as possible and should be braced during construc- tion, if necessary. Drains parallel to the track should be laid as close to the track as the stability of the soil will permit and according to their depth, but they should never be nearer to the ends of the ties than 2 ft. The drains should have a fall of not less than 4 in. per 100 ft. In deep trenches and in soft or slipping material only bell-end tile should be used, because it re- tains its alignment better. The tile should be hard-burned and should never be less than 6-in. in size. After the trenches have been excavated to grade, about 3 in. of cinders should be placed in the bottom to keep out the wet clay. The tile should be laid on the side of the trench farthest from the track, but not less than 4 in. from the side of the trench. The sections of tile should be laid from the low end of the grade or outlet upgrade, the bell ends upgrade. Joints should be left open enough to permit water to enter, but not s<3 open that dirt can enter. The upper end should be closed with a block of wood or slab of stone, and the outlet should be covered with wire net- ting to prevent animals from getting in. The backfill should be made of cinders all around and to 12 in. above the pipe. The joints may be lightly covered with hay or straw while the backfill is being made, to keep the joints open. The fill directly over the cinders should be selected material and should be carefully tamped to insure stability of the roadbed. The tile drain is not intended to take care of surface drainage, the ditches providing for this. If all pockets are not tapped and drained by drains parallel to the tracks, lateral drains should be laid at such intervals as may be necessary. Vegetation with deep roots must never be allowed to grow up over the subdrains. Drainage Tunnel to Stop Sliding Clay. H. G. Wray, in En- gineering Record, July 29, 1916, describes difficulties encoun- tered in shifting the Pennsylvania Railroad tracks at Cincin- nati, Ohio. In eliminating a grade crossing it became necessary to shift the tracks into a hillside. Several test pits dug into the hillside disclosed a peculiar formation. The entire hill consisted of a soft clayey material resting on a layer of stratified clay mixed with limestone, which dipped at a very abrupt angle to- ward the river. See Fig. 7. At the first cut of the steam shovel, in preparing the new SLIPS AND SLIDES 1293 subgrade for the railway tracks, serious cracks developed in the hillside, endangering a block of houses. A concrete retaining wall was planned to replace an existing stone wall. Meanwhile the foundations of 10 or 15 houses be- gan to give evidence of the sliding action of the hillside, as large cracks began to appear in them, damaging the property to a con- siderable extent. In view of these houses being damaged when the construction had barely begun, it was decided to buy the property and omit the construction of the retaining wall. During the rainy season of the next year following the pur- Fig. 7. Drainage Drifts Used to Stop Sliding Clay Hillside. chase of this property the sliding action of the hillside increased and cracks developed in the surface of Columbia Avenue, making it necessary to take steps to protect the street. It was decided, therefore, to drain the hillside to see whether this would stop the sliding. Drainage drifts were driven through the hillside at frequent intervals to provide outlets for the ground water and to elim- inate, as far as possible, its spreading out over the surface of the substrata. These drifts were miniature tunnels 4 ft. high by 3 ft. wide. As the digging progressed each drift was sheeted at the top and sides with 2-in. oak plank. Two men working in each drift were able to drive between 2 and 4 lin. ft. of tunnel per day. 1294 HANDBOOK OF EARTH EXCAVATION One man removed the material, while the other hauled it to the mouth of the tunnel by wheelbarrow. After the completion of the drift it was backfilled with coarse rock in order to allow the ground water to flow through it. These drifts were of varying length, owing to the character of the material encountered. They were, however, driven in each case until the underlying stratified clay was reached. Some of them are below the tracks and extend up into the hillside north of the tracks. Each drift was given an outlet to a sewer by a 4-in. drain-pipe connection. They were driven at an average cost of $5 per lin. ft. This scheme of underdrainage has materially relieved the situation, and it is believed that it will be a suc- cessful undertaking. Two years after the work was started, and while the drainage drifts were under construction, a surface talus of 5-ft. depth started to erode and slide. It was decided more practical in this case, since the slide was of comparatively shallow depth, to build a retaining wall to hold the hillside in place. The Treatment of a Wet Cut. Railway Age Gazette, May 17, 1912, gives an account of difficulties encountered at Neff's Cut, Pa. on the Penn. Ry. This cut is 2,900 ft. long, and is located on a summit. It passes through impervious potter's clay, which was depressed under the tracks by the heavy weight of passing trains and raised in the ditches, requiring the constant employ- ment of a large force of men to keep the tracks in surface and line and the ditches open. The extra maintenance cost was about $900 per month. Following surveys made in 1909 the grade was revised and the tracks raised 3 ft., 2 ft. of cinder ballast being used to prevent the muck from reaching the surface. On this was 1 ft. of trap rock ballast. A 24-in. cast iron pipe under the tracks was lowered to a depth of about 6 ft. below the top of the rail, with a good fall and ex- tended by the use of additional terra cotta pipe to an open ditch draining to the river. Manholes were provided in the pipe line for cleaning out sediment. The northern intake of the drain was connected by a covered flume of pipe down the slope of the cut, which drains all the water carried by a berm ditch during periods of heavy rains. As the rainfall is very great it materially assists in keeping main drain well flushed. Where the main drain crosses the side ditches, concrete inlets were installed, also connected by 24-in. pipe on each side with the French drains, which were laid by hand in the side ditches. Standard ditches and slopes were constructed on each side of SLIPS AND SLIDES 1295 1296 HANDBOOK OF EARTH EXCAVATION the cut, the banks were sodded, and a curb of small stone set along the foot of the slope to prevent scouring which would allow the sod to slip. On both sides of the track it was necessary to shore up and excavate through the slough, at the ends of the ties, to the depth of from 4 to 6 ft. and 6 ft. wide; the grade at the bottom run- ning toward the main cross drain. These ditches were filled with large stone in such a way as to provide ample openings to allow the water to find its way to the main cross drain. The weight of the stone combined with its thrusts against the slopes prevents the raising of mud in the ditches. It is interesting to note that where the excavation was being made the men had to leave the ditches when trains were passing, as their weight forced the muck and water from the roadbed into the ditch in small streams, as if shot from a force pump. On the north side of the railway a solid formation exists about half way through the cut, and where the strata of slate and shale end, a heavy retaining wall 2,100 ft. long was constructed to hold back the slopes, which had constantly slipped and filled the ditches. This wall in connection with a large French drain doubly insures against mud raising. Since the completion of this work in August, 1911, it has been possible to maintain line and surface, a standard slope and ditch and to dispense with all extra men, thereby reducing the cost of maintenance of this section by $900 per month. In addition the annoyance of trains reporting daily " track bad in Neff's cut " has been eliminated. The life of rail and fastenings has been increased, % as prior to this treatment the soft roadbed caused many broken splices, line and surface bent rails and the con- stant gaging lessened the life of ties. On account of the density of traffic, carts were used to re- move all excavation. The cost of treatment lasting over two years was $16,577. Large Slides in N. P. Ry. Cuts. Engineering News, Mar. 25, 1915, gives the following: The Day Island cut on the N. P. Ry., 101/4 miles from Tacoma, Wash., gave unexpected trouble, as there were no surface indi- cations to cause suspicion, and in smaller cuts very hard ce- mented material had been found. The cut was in ground slop- ing gradually back from Puget Sound, and was about 700 ft. long with a maximum depth of 50 ft. at the center line. About 200,- 000 cu. yd. of slide were removed by steam shovel in excavating a cut of 100,000 cu. yd. The cut broke back to a maximum dis- tance of 360 ft. from the track at which point a depth of about 130 ft. was reached. It would have been necessary to remove a SLIPS AND SLIDES 1297 larger yardage had not a pile bulkhead been built for a distance of 630 ft. The material in the cut was loam with some blue cla} r , and it carried a considerable amount of water. The Tenino cut was estimated at 131,000 cu. yd., but there were removed before its completion 866,000 cu. yd., or 735,000 cu. yd. of slide. On the north side of the cut there was a slide for a length of 850 ft. extending back for a distance of 680 ft. from the track. Early in 1914 a smaller slide appeared on the south *&#&} k- ,r - H Part Side Elevation End Elevation 'This Timber to bt g-, in Werce when dumping&oop Bart Plan Fig. 9. Front End of Scoop Car Showing Attac Excavating and Dumping. when side. This measured 600 ft. along the track and extended back 270 ft. The greatest difficulty was with the first slide in this cut, where the material was a partially formed sandstone. This material broke up as the slide moved toward the track until it had lost all indications that it had ever been rock. This cut car- ried a very small amount of water. As nearly as could be de- termined the slide was moving on the harder rock beneath it. A small portion of this rock was encountered at grade. A Scoop Car for Handling Railway Slides. Engineering News, July 16, 1914, gives the following: 1298 HANDBOOK OF EARTH EXCAVATION The car ( Fig. 9 ) is 40 ft. long over the end sills, or 54 ft. 8 in. over all ; it is equipped with a 20-ton crane mounted over the center of the front truck, and having a fixed reach of 12 ft. A double-drum hoisting engine with cylinders 8}4 x 10 in. oper- ates the 1-in. hoisting cable and the %-in. swinging cable, the latter passing around a bull-ring at the foot of the mast. There is a vertical boiler 8 x 3i/ ft., with the necessary coal space and water tanks. To the hoisting block is attached a swing beam having a chain at each end. The scoop is about 12 ft. long, 7 ft. 8 in. wide and 3 ft. 4 in. deep inside, with a capacity of 10 cu. yd., and it is fitted with heavy teeth on the edge. The car and its machinery weigh about 90,500 lb., which the scoop in- creases by 16,900 lb. When excavating, the front of the scoop is attached to the chain hooks and its rear end is held by a pin and backed against a heavy bumper in front of the car, the bumper being supported by inclined braces from the sills. When the scoop is loaded, its front end is raised clear, and the car is run out. At the dumping point, the scoop is lowered upon the rails, with a timber or metal block under one side ( as in Fig. 9 ) . The chains are then de- tached from the end and hitched to lugs on the bottom of one side, so that the scoop can be tilted and emptied. The car was used in moving a slide on the west bound main track of the Norfolk and Western R. R., which was approxi- mately 110 ft. in length and 5 ft. deep, containing about 800 cu. yd. It required 10 hr. with the scoop car to move this and con- vey it from 100 to 150 ft. from the point of the slide. The labor cost for handling the above quantity of material, which consisted of dirt and rock, amounted to $182 (including work-train cost, etc.), which is 22.7 ct. per cu. yd. On occasions when it has been necessary to use the scoop car for handling slides it has proved very satisfactory. Two Methods of Stopping Slides. H. Rohwer, in " Bulletin No. 90 " of the American Railway Engineering and Maintenance-of- W T ay Association, gives the following: At the west entrance to the Oregon Short Line tunnel in Idaho, where the sides broke off vertically and heaved the track at times to such an extent as seriously to interrupt and delay the handling of material from the tunnel, good results were obtained with ordinary horizontal bracing, in the manner shown in Fig. 10. " A most remarkable slide was encountered on the White River Ry., at the entrance of a tunnel 2,650 ft. long (Tunnel No. 3, at Omaha Drive, Ark.), its magnitude precluding all thought of removing it. The disturbance first manifested itself at a side- SLIPS AND SLIDES 1299 hill cut. In removing the footing, the mass of clay seemed to lose its hold on the rock whereon it rested. It began breaking off, first showing cracks insignificant in size and their location being confined to the right-of-way, but later reaching far out into the adjoining hills, bringing down trees and forming breaks in the surface 15 to 25 ft. in height and perpendicular. The tunnel penetrates a sag in the Ozark mountains, consisting of a boulder formation, lime and rock being found intermixed with clay, a hydrated silica of alumina of brownish color, due to the presence of iron oxide. This clay is very plastic, especially in the ap- Fig. 10. Method of Bracing a Cut hi Sliding Material. preaches, where action of water is not constant as in a tunnel. Here the layer of clay was from 5 to 100 ft. thick, underlain with strata of solid rock of smooth surface and slanting at an angle of from 5 to 10 toward the creek along which the line had been located, then in course of construction. The grade of the roadbed entered the rock 20 ft. below the surface; in other words, the approach to the tunnel had a 20-ft. rock cut with clay in the slope overlying it. As soon as cracks appeared on the surface, extra precautions were taken against surface water. The surface ditches were given steeper grades, and, where possible, the bottoms were ce- mented so that the water could drain off more quickly, thus re- ducing chances of penetration to a minimum. In spite of this the ground continued to break, and started to move toward the open cut, at first dropping into it little at a time. It gradually increased, until after a rather heavy rain the entire cut was filled with this stuff, involving an expenditure of $1 per cu. yd. for its removal. Though the moving masses had adopted a slope of nearly 1 on 2, the breaks continued, stretching for more than 150 ft. into the hill above the grade of the roadbed, and over 500 ft. distant from it. To prevent similar occurrences after the road was in^operation, the rock cut was arched over for a distance of 600 ft. from the portal of the tunnel (see Fig. 11). An arch, framed of timber, 1300 HANDBOOK OF EARTH EXCAVATION without protection against " side pressure," cannot be relied upon as a permanent safeguard against slides. To make it serve, how- ever, should the mass continue to move, the clay bank was re- moved for a distance of 12 ft. from the edge of the rock cut, and holes were drilled into the rock 8 to 10 ft. in depth, and from 10 to 15 ft. apart, in a row along the foot of the clay slope, shots being placed therein and fired simultaneously by means of an elec- tric battery. The rock was broken but not scattered, a trench- like crack appearing at the surface. Logs were cut and placed alongside each other with the butt end in the rock crevices, the other end overhanging the timber arch, and resting upon its top. The material under the logs and between the logs and the arch was Fig. 11. Cut in Rock Roofed as Protection Against Sliding Clay. tamped, thus forming a solid flooring over which the material could slide, distributing it over the entire arch and serving as a weight instead of a thrust. The further object of cracking the rock was to permit the water coming through the clay to escape, thus leaving the footing dry and in better position to act as a support. /The plan worked very satisfactorily. The first rain produced another slide, the logs carrying the material over the arch. With the drain in the rock at a distance of 12 ft. from the edge of the cut and over 30 ft. from the foot of the new slope, a good foothold had been created which served the purpose, for no further movement of the over- hanging masses (estimated at 130,000 cu. yd.) has taken place since that time (1904). The few sticks of timber in the arch which had moved, were displaced not more than an inch. Holding Slides by Piles. The following is from a paper by R. P. SLIPS AND SLIDES 1301 Black, Proc. Am. Soc. G. E., Vol. XXXVI, abstracted in Engineer- ing and Contracting, June 8, 1910. The southern portion of the Kanawha and Michigan Railway, for 93 miles (from Point Pleasant to Gauley Bridge, W. Va.), is located on the east side of the Great Kanawha River. For about one-third of this distance the road is close to the banks of the river, on a hillside location, where there is practically no valley, the mountains rising directly from the stream. Owing to the character of the soil, there is considerable trouble, due to land- slides and slips, the term slips being used where the fill, or em- bankment under the tracks, settles or slips toward the river. At Leon, where considerable expense was incurred in maintain- ing the track around a slide, the hillside was removed, and the track, for 2,000 ft., was relocated on the rock bottom, obtained by cutting back to a side hill location. By this method the en- tire landslide was removed and the track put on rock bed, thereby doing away with the trouble, at a cost of $20,000. At Cannelton, where the largest slow-moving landslide occurred, the main track had been pushed out of line. Reverse curves were made, in order to get back to the alinement, but on account of the continual sliding, the curves became too sharp for opera- tion, and the side track "between the hillside and the, main track became completely covered. As this slide was of such extent and depth, it was out of the question to remove it in order to get ba'ck far enough for a rock sub-grade, as at Leon. The change of line not being feasible, it was proposed to remove part of the land- slide, permitting the relocation of the tracks on their original alinement and, after completing this, to protect them from further slides. A steam shovel was cut in at one end, and removed enough of the landslide to allow the two tracks to be changed to their or- iginal location. After the shovel had worked about three daya a slide occurred one night, half burying the shovel. Steps were then taken to hold back the hillside before further slides could develop. This was done successfully by driving two parallel rows of piling, 5 ft. apart, about 3 ft. from center to center, as shown in Fig. 12. The upper rows, against the hill, were backed with 3-in. plank, the front rows being driven against this brace in order to aid in supporting the upper row. A lOxlO-in. stringer was placed against the upper row, and from this 8 x 8-in. braces were carried diagonally, at an angle of 45, to the lower row of piles, and these were sawed off -at the ground level. Steel bands, with 1-in. rods to hold the two sets of piling together, were put on about 8 in. below the top of the brace pile. The depth of pene- tration of the piling varied from 15 to 30 ft. The piling was 1302 HANDBOOK OF EARTH EXCAVATION selected large white oak, and oak timber was used for the stringers and braces. Moving the shovel ahead about 30 ft., then cutting it back, and driving the piling as shown, constituted a day's op- eration. The work was completed successfully without further serious landslides. In four weeks about 12,000 cu. yd. of earth were removed, the track was thrown back to its original aline- ment, and the landslide was stopped. This work cost $16,000. The upper limit of the slide is about 135 ft. above the track. The slide consists of about 200,000 cu. yd. of moving earth. This work was done in the spring of 1907, and has been successful. At several places, due to excessive pressure, the braces have been Fig. 12. Pile Brace Against Landslide. embedded in the stringers. The earth from the top of the piling was given a slope of 1^ to 1. At several other points smaller slides have been stopped with one row of piling. The piles were driven 3 ft. c. to c. and cut off 3 ft. above the top of the rail, the ground above being given a slope of 1"^ to 1. At one or two places, where one row was not sufficient, the trouble was stopped with brace piling. At points where the single row of piling showed signs of leaning, due to the pressure against that part of the piling above ground, this overturning, apparently due to too much length above ground, was stopped by cutting off the piling 3 ft. above the ground and giving the earth above it a slope of 11^ to 1. In contending with landslides of this character in West Vir- ginia, all that seems to be necessary is to obtain a good toe hold, which stops the movement of the earth above. The so-called slow-moving landslides on the Kanawha & Michigan Ry. have been stopped successfully by one of these methods. SLIPS AND SLIDES 1303 The term " slips " is applied to places where the soil slides into the river. These slips occur when the roadbed is con- structed on a fill, ranging in depth from 5 to 10 ft., across narrow flats, between the hill and the river. Due to the constant move- ment of the earth, no trees grow on the land between the river and the railroad. The ground slips gradually into the river where, from time to time, its toe is cut away by the current. The peculiarity of these slips is the fact that they may con- tinue for one or more seasons without giving any trouble. Slips are due to high water and not to surface water. A quick rise and fall of the river will not cause the soil to move, but con- tinued high water, or several successive floods, will start the slip- ping action. In the spring of 1908, the length of track affected by the slips was 7,600 ft., necessitating, at several different points, the main- tenance of speeds ranging from 6 to 20 miles per hour for five months, until the dry season, when this slipping action stopped. In Fig. 13 is shown a cross-section of the Brighton slip, which gave the greatest trouble. The section is taken at right angles to the track, the information for which was obtained by levels and test rods driven to rock. A stratum of rock, below the earth, slopes toward the river, ranging from 1:0.2 to 1:1. This rock is covered by successive layers of red clay, varying from 3 to 6 ft. in thickness. Immediately above the rock, and in thin seams, from 4 to 8 in. thick, between the layers of clay, is found a quick- sand mixed with fine clay. When the quicksand and fine clay be- come thoroughly saturated with water, the mixture affords a smooth surface over which the top soil or successive layers of clay slide toward the river. After high water these seams of quick- sand can be traced readily by the water seepage. The quicksand is very slimy, and contains no grit. The water must remain over the ground long enough to force its way back into this quicksand and saturate well before the slipping action can take place. In 1908, in order to keep the track safe, the gangs on four sec- tions were increased from three the normal force to ten men each, and these increased forces were maintained for four months. The tracks had to be resurfaced and lined continually. At three different times, it was necessary to put on filling material and bal- last in order to keep the track up to grade. This entailed a cost of $4,400 more than the normal expenses for the year. The track over the slips was not only costly to maintain, but dangerous, due to wrecks resulting from derailments on account of rapid settlement of the roadbed. At Poca, where a trestle was maintained over a slip for about 800 ft., due to the heavy cost of changing the alinement, the 1304 HANDBOOK OF EARTH EXCAVATION SLIPS AND SLIDES 1305 trestlework was filled with heavy quarried rip-rap, and the fill was widened so that the stone reached the river's edge. The weight of this stone fill caused settlement, but, after adding stone from time to time for five years, the roadbed became solid. It is thought that the stone fill settled to the rock stratum below the slip, thereby stopping the movement. In the spring of 1909, test piling was driven for a distance of 50 ft. in the center of the Brighton slip. Transit observations taken from a base line, showed that the piling did not move any appreciable distance. The track held up well within the limits of the piling where, as on either side, it had been necessary to re- surface continually. The test being successful, two rows of piling were driven, one on each side of the track at the Brighton slip, and between its limits, for a distance of 740 ft. The piles were equipped with steel shoes and were driven 3 ft. apart, center to center, on the down-hill side. Continuous 8 x 16-in. timber bracing was bolted to the piling. The work was done with a self-propelling track- driver. A temporary spur track was constructed at one end of the slip, thus dispensing with the services of a work train. The cost of this work was as follows: Hardwood piling, 8,075 ft. at 13 ct $1,049.75 Steel shoes, 12,690 Ib. at 3 ct 380.70 Labor 856.35 Fuel, etc 120.00 Total .'.;:..'.;. ./.'.I. j i ! . .. $2,406.80 Up to the present time (Sept., 1910) this remedy has been suc- cessful. At another point, where the rock strata are not at great depth it is proposed to go down the hillside about 20 ft. from the track, put down holes about every 20 ft., and blast the smooth surface of the rock. Thus, by roughening the surface and destroying the stratification, the sliding of the clay may be stopped. Stopping a Slide by the Use of Explosives. Engineering Neics, July 1, 1915, gives the following: The Pennsylvania Co. on its C. & P. division recently built a spur track about a mile long from its main track to the plant of the Pittsburgh Crucible Steel Co. at Midland, Penn. In exca- vating for the new roadbed, which for a portion of the way lies along and below the Ohio River Passenger Ry., a bad slide de- veloped about 1,700 ft. long, extending back from the cut a maxi- mum width of about 350 ft. to the face of a rock cliff. About 40,000 cu. yd. of material in excess of. the preliminary estimate slid into the roadbed prism and was removed by a steam shovel. 1300 HANDBOOK OF EARTH EXCAVATION Fig. 14 shows an approximate typical section through the slide. For a time it was necessary to abandon the track on the side to- ward the new cut, using the other track past the slide. The track being used was lined back up the hill from time to time and brought to surface with blast-furnace slag. In a thorough study of soil conditions it was found that a slid- ing plane existed at the top of a bed of fire clay about 10 ft. below the surface of the sliding mass. o \oo' ax>' -wo' -wr Fig. 14. Cross-Section Through Slide. Holes large enough for a man to work in were dug on 15 -ft. centers to the surface of the fireclay. Then a 2-in. hole was drilled 10 ft. into the clay and the lower end chambered with two sticks of 40% dynamite. Three kegs of black powder were then placed in the enlarged hole and the charge fired. The clay was lifted into mounds which connected into each other at about the surface of the clay. This method of stopping the slide proved a complete success. European Railway Practice for the Prevention of Slides. There is much in print on this subject by both French and Eng- lish engineers. Many of their methods can have but little appli- cation in the United States. However, it is desirable to know a great variety of methods of overcoming slides. Even the most laborious of European remedies may find occasional application in America. The following is from " Notes on the Consolidation of Earthworks," by Jules Gaudard (translated from the French by James Dredge, C. E.) and published as paper No. 1274 in the Proceedings of the Institute of Civil Engineers, Vol. 39 (1874-5) : The theory of the thrust of earth against retaining walls is well known. In Fig. 15, the retaining wall is designed to hold against the thrust of the prism ACX sliding along the line CX. SLIPS AND SLIDES 1307 Fig. 15. Fig. 16. Fig. 17. '] tl * 1 -iW. Fig. 18. 1308 HANDBOOK OF EARTH EXCAVATION If however there is a water bearing seam at CD the hypothesis of the theory of earth thrust is not tenable, and it may be im- possible to construct a stable retaining wall. Earth laid in layers behind a retaining wall possesses a sliding tendency which destroys the hypothesis of the homogeneous the- ory. It is preferable to place the earth in well rammed layers in such a manner as to form stratifications the sliding angle of which is in the opposite direction to the thrust against the wall. Where sliding ground makes retaining walls unfeasible the earth must be retained by strutted walls provided with sufficient outlets for drainage. The walls of the Billsworth cutting (London and Birming- ham Ry.) are strengthened by counterforts strutted underneath the road bed (Fig. 16). Over head strutting is applied in the case of high walls which threaten to turn over rather than slide out at the base, as for example on the inclined plane at Euston, Fig. 17. Fig. 18 shows an arrangement of masonry struts, with counter- forts spaced 21 ft. apart; the wall itself being counter arched between counterforts, to check it from yielding under pressure from the back. Masonry struts, placed 15 ft. apart, and of the form shown in Fig. 19, serve to strengthen the retaining walls of the Chorley cutting (Boltyn and Preston Ry.). These are formed with upper inverted arches to give them additional stiff- ness. When the cuttings are in side-lying ground the struts should be inclined, as in Fig. 20. Where there is only one side of a cut to be retained or where the two sides are very unequal thick dry stone walls may be employed, strengthened by long internal counterforts, as in Fig. 21. This class of masonry acts as an efficient means of draining the slope behind and it gradually becomes hardened into a com- pact mass, forming, together with the counterforts that strengthen it, a body of firm earth and stone able to retain the mobile ma- terial above. Fig. 22 shows an inclined wall with counterforts used on the Versailles railway. The slope of the cutting of Brigant (Bles- mes-Gray) is supported by inclined arches laid on the slope, the space between being filled with dry stone. The bases of the piers rest upon a continuous footing along the side of the roadway, connected with a similar one on the other side by means of in- verts. The slope is drained by pipes leading to a central cul- vert at C below the invert, Fig. 23. Causes of Landslides. In considering the physical properties of earth and their relation to slides attention is called to the marked tendency of clays to shrink and crack as they dry out. SLIPS AND SLIDES 1309 Fig. 22. j.6 t * J 10 Fig. 23. 1310 HANDBOOK OF EARTH EXCAVATION Rain penetrates these cracks or fissures and soaks into the clay which expands. Renewed dryness opens the cracks wider than be- fore. If, in connection with these fissures on the surface, under- lying water-bearing seams exist in the clay, slides are very likely to occur. In Fig. 24, when the fissure A B descends near enough to the water-bearing seam C E the fall of the mass ABCE is im- minent although no disorganization other than the fissure A B has occurred. The chief means of dealing with these slippery formations con- sist: (1) in insuring the free discharge of the water by means of channels, drains or filters in such a manner that the ground shall be gradually dried and consolidated; (2) in taking off the rain or surface water as rapidly as possible, by means of im- permeable coverings, benches, or ditches; (3) in preserving the loamy soils from the action of the sun, rain, and frost, and some- times in protecting the foot of slopes with walls or simple coun- terforts of well-rammed earth. Concerning the proper slopes to be employed in cuttings in bad ground it is well to increase them to 2 or 3 of base to 1 of height instead of employing 11^ to 1 or 1 to 1 which are applicable in good material. Cuttings. The side slopes of a cutting may be drained by the construction of channels (Sazilly system) if the water-bearing seams are clearly defined; by pipe drainage if the distribution of water is more vague and general; and lastly, by filtration in the case of water bearing sand. Water Bearing Strata. In water bearing strata, in some in- stances, a deep narrow trench has been excavated in the bank at a sufficient distance from the face of the slope. The trench is timbered and filled with dry stone, as in Fig. 25. The planes of moisture in the prism ABC dry up, and the earth gradually and surely becomes consolidated. This method is good but costly; it may be employed to arrest movement already commenced. Sazilly devised a more economical system of small longitudinal drains established near the face of the slope, and formed in the vicinity of the seam. At the bottom of a cutting in the face of the slope, is placed a channel formed transversely of three flat tiles set in hydraulic mortar. Or the channel can be formed with a single row of half round tiles. Round or broken flints 2 in. in diameter, or sometimes furnace slag, are thrown over the channel. The largest pieces are placed below and the smallest nearer the water bearing seam. This stone filling, heaped against the vertical side of the cutting in the face of the slope, is always high enough to cover any irregularity in the line of the water discharged. The surface may be covered with turf or with a layer SLIPS AND SLIDES 1311 of clay or matting, with tiles or with flat stones to keep out the mud which would gradually choke the drain. Two lines of water discharge at least 18 in. apart can be served by the same channel. This system of drainage is laid in the face of the slope with gra- dients of at least 1 in 100. See Fig. 26. of 'Water Fig. 24. Fig. 25. Fig. 26. A slope of loamy soil should be completely covered against the action of weathering. The revetment may be executed of rammed earth in successive layers from 6 to 8 in. thick, laid with a slope opposed to the face of the bank. The face of the bank should be furrowed as in Fig. 27 if the slope is steep. Ordinary turfing would be insufficient, whereas sods laid as in Fig. 28 would be .fpstly, and still permit water to enter between the interstices. 1312 HANDBOOK OF EARTH EXCAVATION In deep cuttings commanded by higher natural slope it is of great importance to check the action of the surface water. With this object a ditch is formed at the foot of the natural slope, Fig. 27. Fig. 28. as in Fig. 29. This ditch must be of clay, puddled to make it impermeable. An open channel in stone or brick, as in Fig. 30, is better as it is less likely to let water percolate. A still better Fig. 29. method consists in dividing the face erf the slope into a number of stages in such a manner that the action of the surface water is greatly reduced. The top of each stage or bench is given a 30. reverse slope of 15%, forming a channel which conducts water to drains laid at intervals on the surface of the slope, as in Fig. 31. The channels up the side of the cutting, which take off the water SLIPS AND SLIDES 13 from the trench drains can be formed of small stones covered the revetment, and resting on the natural ground, as in Fig. J Pipe Drains. When water-bearing seams are numerous, regular, or indistinct, pipe drains may be employed wherever a: Fig. 31. discharge of water shows itself. On the Croydon and Birmingha railways in England the efficiency of pipe drains has been i creased by making numerous small openings in them, enlarged t ward the inside, as in Fig. 33. Owing to the form of the holes ai mud which may enter from the outside of the drain frees itse immediately and passes off with the water. A line of drain pipes is placed along the crest of the slope, ai Fig. 32. from this line others decend transversely into the side dite At regular intervals a vertical pipe, C in Fig. 34, rises from tl main line for the purpose of ventilation. The circulation of a thus obtained causes the deposit left in the pipe in dry weather 1 crack, and thus it is easily removed the first time water passi J14 HANDBOOK OF EARTH EXCAVATION rough the pipe; on the other hand this arrangement causes a oking vegetable growth within the drain. The pipes are laid or 6 ft. below the surface, toward the foot Qf the slope and 3 ft. neath at the top. They are spaced about 15 ft. apart. Fig. 33. Fig. 34. Fig. 35 shows an arrangement used on the railroad from esmes to Gray, France; drain pipes 1.8 in. in diam. are laid in. below the slope and from 10 to 20 ft. apart. These dis- arge into longitudinal collectors placed near the side ditches, third central collector drains the roadway and is placed in con- ction with the two lateral drains by pipes laid from 32 to ft. apart. They are formed by pipes 3.34 in. in diam. and are vered with broken stones. Fig. 36 shows a drainage system used on the Eastern railway France. Drains at least 2. 30 in. in diameter, surrounded by a tering material, and with a minimum inclination of 1 in 200, e laid in a deep narrow trench M N to the rear of the top of the >pe. On that side of the trench farthest from the face of the >pe are placed small vertical pipes about 6} ft. apart. These pes are stopped short of the surface of the ground and com- unicate below with the longitudinal drain. The trench is then led with earth and well rammed. Other collectors beneath SLIPS AND SLIDES H, 13 the side ditches drain the formation to a depth of 4 ft. The ma M N E C D being thoroughly drained by this means, acts as counterfort to resist the thrust of the moist ground behind M The Ashley cutting on the Great Western railway, Englar was drained by a system of inclined transverse galleries a: sumps, connected by a longitudinal gallery in such a mann as to tap all the water-bearing seams. On the Great Easte railway the slopes were drained by sumps filled with brok stones, and by discharge pipes. M A cutting in the North of Spain was attended by land slips, $ though the stratifications were normal to the face of the upp slope. In such a case water is retained in pockets and can 1 removed only by a syphon. Collecting wells were sunk and su rounding trenches were made as well as a system of galleries. On the Western railway of Switzerland drain pipes were laid the slope, as shown in Fig. 37, in such a way as to drain a co: siderable thickness of earth. A number of pipes are joined t Fig. 37. Fig. 38. gether with sleeves, as shown in Fig. 38. These sleeve joints ai kept in place by means of an iron wire from one to another. Tl built up length of pipes is shoved into a hole in the face of tl slope formed by a boring tool. Filter Drains. In water-bearing sands which discharge fro: their whole mass, drainage can be only partially successful, an it is necessary to have recourse to filtering appliances, coverin 1316 HANDBOOK OF EARTH EXCAVATION the whole of the slope which is to be consolidated. On the North- ern railway of France there is reset a stone facing from 5 to 6 in. thick, covered with stone packing or turf 12 in. thick. A 9 or 10-in. revetment is sufficient to keep out the frost which would stop the water discharge. Gravel fascines, shown in Fig. 39 and 40, should be used where there is an abundant flow of water. They are formed of envel- opes of brushwood fastened with iron wire and filled with gravel Fig. 39. Dr broken stone. These fascines are laid in horizontal furrows Formed in the face of the slope. A layer of gravel 4 in. thick is put on to equalize the surface, and the whole covered with turf Dr dirt. Sometimes in very fluent sands the side ditches of the road bed fill as fast as they are made. The most efficient remedy igainst this is to place, first, two fascines as shown in Fig. 41, ind to excavate the intermediate material. At the end of a few Fig. 41. Fig. 42. lays the upper bed will be drained and two other fascines may je laid at a lower level and so on, finally the ditch is lined with jtone, as in Fig. 42. Restoring Cuttings After Landslips. When a landslip is not fery considerable it is sufficient to raise it completely and jromptly, so as not to allow time for fresh slips. The new ground is then drained and strengthened with a counterfort. On ;he line from London to Birmingham and on the Croydon rail- SLIPS AND SLIDES 131 way some local slips were restored with counterforts of dry stoi and gravel. In some cases it may happen that the glacis of a slip, MN Fi 43, may be below the level of the side ditch. It is then advisab to build it up again with carefully rammed earth. With land slips of a larger scale, in many cases the principj part of the fallen earth may be left in place. Fig. 44 shows tl treatment of a land slip in the Hundsoff Cutting of the Wisser bourg railway. An excavation A B C D was made of sufficiei extent to lay bare the undisturbed ground, and at the foot a open drain, C, was formed. If the material is very soft this e: cavation must be timbered, but it is sometimes firm enough 1 -cffia 'fiii 'to noiJib . i . allow the earth excavated to be thrown temporarily on top of tl slip, as at G. The drain is covered with turf, then a ramme earth counterfort, B D, is formed and finally the excavation : refilled with earth from Gr. If the fall of the water-bearing seal is insignificant it is necessary only to clear away the portions that have fallen on the way. A new face slope is formed, whic is covered with 12 in. of rammed earth. The top surface of tl slip ought to be evenly dressed and all cracks stopped up to pn vent entrance of rain water. In land slips of considerable lengt parallel to the way, it is advisable to form transverse cutting at intervals, connecting the low points of the drain with the sid ditch. 1318 HANDBOOK OF EARTH EXCAVATION It is especially advisable in cases where the angle of slip is considerable, to prevent the recurrence of such an accident by retaining the ground with a rammed earth bank, separated from the slip by a filtering wall of broken stones, as in Fig. 45. Fig. 45. Sometimes the slip hollows out the subsoil, remains more or less charged with water and tends to fall further upon the road- bed. It is then preferable to excavate the upper portion, M N P in Fig. 46, and at the same time the face, N P, is exposed for drain- age. Fig. 46. The Consolidation of Embankments. The simplest treatment for yielding foundations is to add material to the embankment until subsidence has ceased. This is often too costly and other means of consolidation are required. The condition of the sub- soil can sometimes be improved by driving a large number of short piles or by excavations in the form of truncated pyramids, filled afterwards with compact clay. Generally the true solution consists in draining the subsoil. Fig. 47 shows the method of draining the foundations of an embankment at Val Fleury on the Versailles railway. Two large parallel drains were formed on the lower side. These drains, from 39 to 50 ft. deep, were connected together and led all the water away in such a manner that the foundation was dried, arid was surrounded and maintained as by a protecting belt. Between Otzaurte and Oazurza in the North of Spain, moist valleys are met with, where the soil of clay and marl slips on schistose strata. Several embankments on the northern line yielded at the base, and it became necessary to surround the area SLIPS AND SLIDES 1319 on which they stood by a double network of drains; encircling ditches with discharge culverts for the surface water; then for the internal drainage, galleries 5 ft. high and 39 in. wide were driven along the schist, and cutting into it from 15 to 20 in., in order to stop subsequent movement and to drain the sliding surface. These galleries followed the irregularities of the rock in such a manner as to involve slopes of from 1 in 33 to 1 in 17. They were then filled with a mass of broken stone leaving a space at the top clear of the fissures which admit the water. Sand, Fig. 47. _ Sliding Embankments. Embankments are often built without consolidation for the sake of economy. If they are of poor ma- terials and become saturated they are apt to slip. Where a central core is made by end dump and the embankment widened by side dump, slipping is very likely to occur. Such an embank- Fig. 48. ment may be thoroughly consolidated by the addition of counter- forts of carefully rammed earth, separated from the earthwork by a filter of broken stone, about 1 ft. thick, or by a wall of gravel fascines. See Fig. 48. It is preferable to execute these counter- forts in advance with earth taken from the site as at a b c d e a. By doing this they can have time to consolidate. They should be 1320 HANDBOOK OF EARTH EXCAVATION rammed in inclined layers in a direction the reverse of the slope of the embankment. On side lying ground an embankment may slip even if formed of good material. It is necessary in such cases to trench out the natural surface, as in Fig. 49 in order to give sufficient hold. Repairs of Fallen Embankments. When the slope of an em- bankment has fallen, it is advisable to remove the foot by s'hort lengths, and to replace the excavation at once with well rammed earth in horizontal layers, or in beds inclined the reverse way of the slope. Fig. 50 shows an arrangement adopted on the Vendeuvre em- bankment for a length of 230 ft. A portion of the fallen ma- terial was left, being covered with a counterfort of rammed earth and new ground above, while the drainage was effected by means of a gravel filter standing in a brick channel. - ..... 2$'.. .. Fig. . 50. Fig. 51. On the Moncerf embankment ( Paris-Coulonmers railway) the filter is of broken stone surrounded by matting. At some parts it was necessary to form two of these filters within the fallen portion of the work, Fig. 51. They are connected together and to the outside slope by transverse drains. Two superimposed coun- terforts retain the filters. On the Main-Weser railway some clay embankments slipped and were restored with sand. Pockets filled by sand became sat- urated with water and were drained by pipes covered with 5 ft. of broken stone, A B in Fig. 52. On the \Yissembourg railway the sides of the fallen embank- ments were drained by means of transverse trenches in which SLIPS AND SLIDES 1321 were placed gravel fascines, as in Fig. 53. These were afterward covered with a facing. of good earth combined with the fallen ma- terial, and well rammed. Fig. 52.Ua i> ' jjstytneo c4ni j/njjtf Ji/i// i;i'ff> lo.'jur ^rt I' .i^i Stopping Slips on the Nottingham and Melton Ry. This work is described by Edward Parry, in paper 1756, Proc. Inst. C. E. In the cuttings through the boulder clay where the material was homogeneous no slipping to any appreciable extent took place, but where pockets of sand occurred in the shale and clay, the slopes gave considerable trouble, continually breaking off verti- cally at the back from the top, after being trimmed to a slope of l% or 2 to I. Water was generally found in the sand, at the base of the slips, and was apparently the cause of them. These when small were frequently cleared away entirely down to the solid, and the line of slope restored by filling in with burnt bal- last, broken boulders, or other convenient hard dry material, which allowed the water at the back to drain off without doing further injury. Where, however, the slip was very large, extending, as in one case at the north end of Stanton tunnel, 6 or 7 chains along the slope, and from 20 to 40 ft. in depth, another method was pursued : a deep drain parallel to the line of railway and 4 or 5 ft. wide was taken down at the back of the slip to the solid ground, and filled with burnt ballast; cross drains were cut from it to the face of the slope to bring out the water, and the toe of the slip was secured by being burnt for a width of about 20 ft., the whole being finally trimmed off to a flatter slope. Two large slips occurred in cutting No. 9 in the lias shales, on opposite sides of the line, somewhat similar in character to 1322 HANDBOOK OF EARTH EXCAVATION those before described, breaking off vertically at the back from near the top of the slope. In this case the bottom of the slips extended underneath the formation of the railway, and the toe of the one being pressed on to the toe of the other, by the weight at the back, caused both slips to turn and rise upwards, lifting the ground several feet. In fact, a gang of men had to be continuously employed lowering the temporary roads in order to keep the work going. These were dealt with in the following manner : In addition to drains at the back and a toe of burnt ballast on each side, the slips were cut down to the solid ground in the center line of the railway, varying from 3 to 9 ft. under the formation level, and cleared out for the full width, the space thus excavated being then filled in with rough furnace slag, which entirely prevented any further lifting, and upon which, after being ballasted, the permanent way was laid. The burnt ballast and drains afterwards kept up the slopes of the cutting, which were trimmed to an irregular batter. Paper 1760, Proc. Inst. G. E., by John William Drinkwater Harrison, contains the following: In treating slips on the Nottingham and Melton railway two methods were mainly adopted. 1st. The toe of the slip was burnt into a compact mass of bal- last, the width at the base varying from 8 ft. to 20 ft. or more. This retaining wall, for such it virtually was, having been formed, the foot of the slip was weighted as far as possible, and the slope was left concave where practicable, having a versed sine one-thirtieth of its length. The foundation of the ballast heap was 2 ft. below the original surface. In no case did this wall of ballast give way, though in several instances the slip rolled completely over it, and a fresh heap had to be formed at a greater distance from the line. As the circumstances were ex- ceptional, any details as to cost would be misleading; but it may be stated that 1 ton of coal was sufficient to burn about 10 cu. yd. of ballast. 2nd. Trenches were cut through the slips at right angles to the direction in which the ground was moving; the width of these trenches varied from 2 to 9 ft., and having been carried 18 in. or 2 ft. into the solid ground below the line of the slip, they were filled with stones, the whole of the timbering necessary for their excavation being, generally speaking, left in. This is ob- viously a costly process, and was only adopted in extreme cases, where the slips were delaying the opening of the line. In excavating the trenches it was noticed that but little water was tapped at a lower level than 3 or 4 ft. below the surface. That they must be regarded as counterforts to strengthen the slips SLIPS AND SLIDES 1323 more than as means of drainage was shown by the fact that several weeks after their construction the surface of the bank 3 ft. away from the trench was in a soft, boggy condition. Re- garding them, then, simply as counterforts intended to strengthen a moving mass of weak material, it was thought that to carry them completely through that mass would defeat the purpose for which they were formed, and allow the slip, or succession of slips, to continue their course between the walls. It was found that carrying them about two-thirds of the way through the slip ef- fectually checked its progress, and it seems probable that a less distance than this would have sufficed. In all cases, where the trenches extended to the back of the slip, there was no great quantity of water. The cause of the majority of the failures appeared to be the inability of the ma- terial to support its own weight, consequent on the quantity of water with which it was charged; that this water is held in sus- pension for a great length of time appears probable, and the fact that the heaps of ballast over which the slip had rolled were found, when opened out, to be in a dry and dusty state, shows that the plastic nature of the clay prevents gravitation, and the process of evaporation in a deep bank must be slow. More than once where the base of the slip was on the same level as, and extended to the bottom of, the ordinary open side ditch, a pipe- drain filled with rubble was substituted with advantage. Improving Sliding Material by Burning. William George Laws describes, in paper 1810 in the Proc. Inst. C. E., a method of combatting slides on the North Eastern Ry., England. The line runs through the alluvial clay on the north bank of the river .x. Lxazmtcdi svurlvt* Section of Brick-fields. Fig. 54. Section of Bank in Brick Fields. Tyne. This is a tenacious flaky brown clay; the flakes, which vary from y$ in. to 1 in. in thickness, being separated by films of fine sand, and holding water obstinately. The upper and lighter-colored bed varies from 6 to 12 ft. in thickness, and be- 1324 HANDBOOK OF EARTH EXCAVATION low this lies a bluer-colored, more unctuous clay, similar in its flakes and partings to the browner clay above. The lower bed is extensively worked for brick making. In the brick fields, where no attempts to hold up the banks is made, the nature of the slipping is clearly shown. The banks break as in Fig. 54, slopes of 10 or 12 to 1 being reached without the ma- terial coming to rest. Fig. 55 shows how the clay slid into the railway cuts, and the method adopted for burning it. On a decided slip occurring the first thing done was to clear away a space of 15 to 20 ft. in the line of the cutting, until the solid clay was reached both downwards and sideways. A good Fig. 55. Line of Slip in Cut and Method of Burning Clay. fire was then lighted on the solid ground, using plenty of broken wood and coal, and allowed to burn up well; on to this the clay was cast from both sides, in layers varying from 12 to 30 in., small *coal being spread between, until the heap was from 8 to 12 ft. high. This was allowed to burn out on the one side and con- tinually extended on the other, as in firing a clamp of bricks. The burnt material from the cool side was then cast back as soon as possible into the void in the slope, and trimmed to shape. The plan adopted was generally successful, though in some of the earlier cases, from sufficient care not having been taken to get well down to the solid clay, slips occurred for a second time, when the process had to be repeated to a greater depth. It was found that a- bed of heavy slag and hard stones, roughly laid on the solid ground as a bed for the fire, very much helped the process by giving a free draught. The general form and position of the heaps is shown in Fig. 55. The material when burnt oc- cupied by estimation from 20 to 25% more room than before, leav- ing a considerable surplus of burnt stuff to go to bank. SLIPS AND SLIDES 1325 The Drainage of a German Railway Embankment. Engineer- ing Neivs, May 10, 1890, gives the following: The Westerwald railway has to pass over several large clay beds. At one point a large embankment started to settle unevenly, sinking in one place and rising in another. Attempts were made to widen the embankment and counter weight the section that had a tendency to rise. These operations being unsuccessful an elaborate scheme of drainage was resorted to. A large culvert was put under the embankment in a tunnel, and was located very low (see e f in Figs. 56 and 57). The width within at the bottom was 4.1 ft., at the top 2.3 ft., the height was 5.58 ft. It was planned so as to tap the greatest possible number of subterranean streams and also to carry off the water in the neighborhood of the broken drain. The culverts, which were filled with broken stone, served also to drain the subsoil Fig. 56. Section of Sliding Embankment. on which the structure rested. In this, they are aided by a ditch g h, with a broad and deep section, the bottom being below the upper surface of the clay bed. All water falling above the embankments will be collected in the ditch and lead to the mouth / of the main drain. From there it passes through a 1.5 ft. iron pipe laid in the culvert. The nature of the case made it necessary that the side drains should penetrate the mass of the embankment as well as the sur- faces of motion. The main conduit, however, it was necessary to protect from all chances of failure; hence its deep position. The side-channels were inclined as shown in Fig. 57. The drains could have been dug without wooden linings, but the clay of the bed in which the side drains terminated became so soft on exposure to the air that it was necessary to put in a heavy wooden casing throughout the entire system. After the main conduit was built and the side culverts were being dug, the pressure of the moist clay was great enough to several times break the woodwork. It sometimes became necessary to widen the drains also on account of the diminution of the section due to the same cause, even if the lining was still intact, though bent. 1326 HANDBOOK OF EARTH EXCAVATION The side drains were driven as far as the ground remained damp. Then they were filled with broken stone. The final step was to lay the iron pipe before mentioned in the principal cul- vert, and to complete the filling of the entire culvert with stones. The method of joining the pipes is of interest. Each section -If?-.. Fig. 57. Plan and Sections of Culvert Used on Wester wald Ry. was about 13.5 ft. long. These had to be connected in such a manner that any motion of the drain would not destroy the conductivity of the line. This was accomplished as shown in Fig. 58. Two pipes are connected to each other by ties running their entire length; then these pairs are joined in the same way. The way in which the ties and the pipes are con- nected is shown in Fig. 58. The rods are bent at one end, laid SLIPS AND SLIDES 1327 against the pipe, and a ring slipped over the ends. The other extremities pass through a flange of angle iron fixed on the sec- ond pipe, where they are held in position by nuts. Two ties are used for each pair of pipes and they are placed at right angles on the successive pairs. Since the completion of the work, all motion of the embankment has stopped. Fig. 58. Method of Connecting Culvert Pipes. Bibliography. " Earthwork Slips and Subsidences Upon Pub- lic Works," John Newman ; " Landslide on the Fraser River, British Columbia," Robert Brewster Stanton, in The Engineer (London), Dec. 14, 1897; "Report on Slides at Panama," by General George W. Goethals, Canal Record (Panama), Jan. 5, 1916; same in Engineering News, Nov. 25, 1915; "Landslides in Quebec." Engineering News, May 27, 1909; "An Earth Slide at Bellevue, Penn.," Engineering News, Jan. 1, 1914; "Earthwork Slips in *>he Cuttings and Embankments of Various Railways, with Their Causes and Modes of Treatment," John Barret Squire, Min. Proc. Inst. C. E., Vol. 62, 1879-1880; " Causes of Earth Slips in the Slopes of Cuttings and Embankments of Railways and How to Prevent or Remedy Them," Robert Elliot Cooper, Min. Proc. Inst. C. E., Vol. 138, 1889; "Landslides," David Molitor, Journal Association of Engineering Societies, Vol. 13, Jan., 1894; " Stopping a Troublesome Slide at a Summit Tunnel," John D. Isaacs, Journal Association of Engineering Societies, Vol. 15, Sept., 1895; "Geology in Relation to Engineering," Stanley C. Bailey, The Engineer, Vol. 101, March 30, 1906; "The Great Land Slides on the Canadian Pacific Ry.," Robert Brewster Stanton, Min. Proc. Inst. C. E., Vol. 132, 1897-98. INDEX Adobe, definition of Aligning a dredge in a canal . . Alluvial Soil, definition of American railway ditcher, co.it with Analysis of hauling cost of scraper work of steam shovel costs Anchorages, cableway Angle of repose Artificial lake excavated with four-wheeled scrapers . . . Auger borings, cost in Okla. . . cost on Winnipeg Aqueduct 70 hook connections for rods . . . Augers, prospecting Gl Austin backfilling machine .... template excavator trench excavator at Alton, 111 at Mpundsville. W. Va. . . . working in clay working in shale Backfill, handling frozen ma- terial puddling rolling Backfilling, Austin machine used for Carson trench machine used for clam shell bucket and hand work derrick and scraper used in Chicago drifting scraper drawn by two teams Keystone traction shovel .... methods and costs of method of payment for Mpnahan machine for miscellaneous costs on smelter construction Parsons, scraper ratio of time digging to time backfilling retaining wall, cost of casting clay scraper used for specifications for tamping and costs trenches under paved streets Backfilling wagon for 802 1 Waterloo machine for 893 600 Balanced cable crane 585 2 Banks, breaking with dynamite 128 cost of trimming and seeding 156 966 Barges, cost, life, repairs 753 224 method of measuring material 300 on by displacement 763 repairing, cost 755 583 treated and untreated timber 7 compared 755 Bates belt conveyor 985 629 Bed rock sluices 1004 75 Belt conveyors 603 72 capacity 604 68 life of* 604 65 used with scrapers on founda- 893 tion excavation 604 915 Berm ditches 904 833 Bibliography, Properties of 838 Earth 18 834 . Measurement Classification and Cost Estimating .... 40 837 Boring and Sounding 84 Clearing and Grubbing 93 Loosening and Shoveling ... 151 Spreading, Trimming and Rolling 164 887 Hauling in Barrows, Carts, 896 Wagons, and Trucks .... 229 901 Elevating Graders and Wagon Loaders 249 893 Scrapers and Graders 334 Cars 386 830 Costs with Steam and Electric Shovels 557 879 Dump Buckets and Grab Buckets 574 797 Cableways and Conveyors ... 614 Dragline Scrapers 668 892 Dredging 764 891 Trenching 902 Ditches and Canals 1003 886 Hydraulic Excavation and 892 Sluicing 1086 Road and Railroad Embank- 223 ments 1146 892 Dams 1245 Dikes and Levees 1275 102 Slips and Slides 1327 Bishop's derrick excavator .... 554 115 Black-waxy, definition 2 885 Blasting, see also explosives 886 ditches in wet material . . .131, 132 897 dredge pit 129 884 dredgeway in channel 130 885 hardpan, cost 127 1329 1330 INDEX Blasting holes for, made by hydraulic giant 1061 frozen ground with horizontal holes 148 method of connecting wires for in ditching 135 mosquito breeding pools 129 pole holes 136 Bleeding quicksand 872, 880 method of unwatering trench 865 wet sand 785 Bonus system, foundation exca- vation with wheel scrapers 308 Boom method of hydraulicking 1004 Booster Giant 1010 Boring and Sounding, Chap. Ill 41 Boring, augers used for 64 cost with augers in Okla. ... 75 cost with Empire drill 76 cost on Winnipeg Aqueduct . 70 hollow pipe used for 75 post hole digger used for .... 81 simple device for 64 Bottom dump buckets 565 Bottomless power scrapers .... 615 scraper 619 Bottomley trench brace 860 Bowman ditcher 971 Bracing and sheeting trenches . 846 Breaking high banks 128 Brick clay excavated by revolv- ing shovel 523 Bridge conveyor excavator on New York Barge Canal . . 988 Brush bulkheads 733 Buck scraper 250 on levee work 253 Buck shot clay, definition of . . 2 Bucket conveyor backfilling re- taining wall 613 elevator plant 613 Fogerty excavating 570 Buckets, see chap. 12 558 bottom dump 565 clam shell 570 classification of 558 for dragline excavator 643 orange peel 567 used with locomotive cranes in trenching 565 Buckeye excavator for open ditches 909 cost with in Everglades . . . 913 traction ditcher 839 Bulkheads, brush 733 of piles and plank 733 of turf to hold hydraulic fill 735 Bull-liver, definition of 2 Burning material to prevent eliding 1323 Cable drills 81 cost with on bridge founda- tion 82 Cable haulage of cars ......... 368, 371 life on engine incline ...... 372 storage drum for dredge cable 681 unloader plow, method of han- dling ................. 375 Cableway, see chap. 13 ....... 575 aerial dump .............. 581 anchorages ............... 583 balanced cable crane ....... 585 canal excavation, cost of .... 600 canal excavation with in soft material .............. 596 carrers button rope 578 579 chain connected 579 Lambert-Delaney 579 coasting 583 costs . . 576 dragline bucket used with on levee work 603 cableway excavators 588 derrick combined with 586 trolley 599 dredging with dragline bucket 602 duplex 576 efficiency on Gatun Locks . . . 598 grab bucket used with 599 hitches for, at bucket and mast 592 hoisting and conveying ropes 577 horizontal 576 incline 580 levee work with 1257 life of main cable 586 lubrication 581 main cable 582 scraper excavator 589 cost with 595 for side hill work 622 skip dumping device 587 systems 570 towers 581 cost of, for scraper, excavator 594 trench 807 trenching for sewer 808 Calaveras Dam, hydraulic con- struction of 1070 slide on 1244 Canal, bank protection against sliding 1282 enlargement by blasting 130 Canal excavation, see also ditch- ing aligning a dredge 690 bridge conveyor excavation on N. Y. Barge canal ... 988 cableway, cost with 596, 600 cars and carts, cost with clam shell bucket, cost with classification of drainage canal contracts to reduce costs ................. comparative costs, wheel scrapers, elevating graders. dragline excavators and steam shovels on Colbert Shoals Canal . ____ 941 949 905 1001 INDEX 1331 953 700 945 954 317 Canal Excavation cutting 1 to 1 slopes with dipper dredge 956 dipper dredges . .696, 697, 699, 959 dipper dredges, 10-yd. capa- city Cape Cod Canal .... 699 15-vd. capacity, Panama Canal 702 dragline machines used for 632, 648, 650, 987, 997 draglines, electrically . oper- ated 659 on side hill irrigation canals 651 dredge and dragline ma- chines, cost with dredging 69' elevating graders and fres nos, cost with floating dredges, use of ... four wheel scrapers fresno scrapers 269, 938 fresno and wheel scrapers . 940 hand work 908 hydraulic dredge 735, 738 hydraulicking 1050 inclines and steam shovels . 981 ladder dredge 711, 714, 955 natural erosion for 963 power scraper 627 scraper boat for sloping canal banks sluicing steam and electric draglines steam shovel, method of using work with 493, 499, 513, 994 suction dredge 666 tower dragline excavator . . 999 wagons loaded through a trap 202 wheel scrapers 282, 944 various methods on N. Y. Barge Canal 991 Canal, irrigation, loss of water in 906 maintenance 974 elimination of weeds hydraulicking silt . . slope trimmer for . . . Canals, navigable Capacity, belt conveyors wheelbarrows Capstan plows horse operated operated from barges .... 981 963 662 396 9T8 978 907 980 604 169' 909 927 931 power operated 929 Car side wagon loaders 192 track throwing 339 unloaders 372 Carriers on cableways 578 Carrying capacity of water . . . . '.1005, 1006, 1007, 1008 Cars, see chap. 10 335 cable haulage of, on curved track 371 capacity of 375 Cars central control, electric haul- age for cost of handling earth in flat and dump cars cost of hauling with gasoline mine motors dam construction by cars and hydraulicking 1236, dumping sticky material from dumping with derricks filling low ground with dredged material flat and dump car costs com- pared on embankment . . . horse drawn 345, 346, hauled by cables by electric locomotives by motor truck haulage system for, in shale pit light railway on highway work 358, 359, loaded through trap by dump wagons moved by hand mule and electric haulage . . . non dumping preventing freezing on -. recommendations for use on steam shovel work repair costs, Panama Canal . rocker double side dump .... rotary dumping side dump static dumping tractive resistance of types of use of unloading by sluicing in small space on Panama Canal wheel scrapers compared with Carson trenching machine . .810 Carts capacity compared to wheelbarrows . . cost with 177 grading railway 177, 178, high cost with rule for cost with table of cost with Caterpillar land leveler tractor traction for dragline excavator wheels Catlinite, definition of Cellar excavation, see founda- tion excavation Center dump wagon Central-control electric haulage Cess Pool, cost of digging .... Channel Clearing, changing channel of a creek in hard 366 381 363 1238 382 382 355 1138 356 368 364 348 369 360 240 344 364 335 434 376 413 338 335 337 335 342 335 341 384 382 374 347 , 830 175 228 170 , 228 1144 178 176 229 329 218 633 220 2 182 366 109 pan dredging silt with ladder dredge 171 705 1332 INDEX Chicago Drainage Canal 981 Chisel excavator for frozen ground 146 Chutes used on ladder dredge . . 710 Clam shell buckets 570 trenching with 571, 783 dredge with 195-ft boom . . . 678 dredging 681, 683, 721 Clamp for pulling sheet piling 852 rail for steam shovel 424 Classification . 25 Am. Ry. Eng. and Maint. Way specifications for 37 according to difficulty of pick- ing 27 common excavation 26, 27 excavation under water .... 27 loose rock 27 overhaul 27 specifications for 26, 29 solid rock 26 Clay 2 breaking uy for a dredge . . . 752 burning to prevent slipping . 1323 casting behind retaining wall 115 cost of cesspool in 109 difficulty of dredging with ladder dredge 709 dredging with clam shell .... 683 excavated by revolving shovel in brick yard 516 foundation excavation in .118, 258 handled in carts on railway work 177 with elevating grader on railway work 241 with wheel scrapers in rail- way cut 305 hand excavated for retaining wall 116 loosening and shoveling 107 shrinkage of 13, 14 sluicing, grades required for 1008 steam shovel work in 366, 451, 455, 457 test pits in 83 thawing with steam jets .... 143 wash borings in, on Stanley Lake dam 52 weight of 4 Cleaning filter plant with wheel- barrows and carts .... 170, 171 Clearing and Grubbing, see chap. 4 85 cost estimating 86 effect of method of excava- tion on cost 88 on cost of earthwork .... 39 factors affecting cost of ... 85 methods 91 roadwork; cost of clearing on 1091 Climate, effect on cost of earth- work 38 Coasting cableways 583 Cofferdam, filled by pumping. . 1215 Combination cableway and der- rick 586 Common excavation 26, 27 Am. Ry. Eng. and Maint. Way Asso. classification . . 37 Compacting embankments, effect on cost of earthwork .... 40 Comparison of steam and elec- tric shovel costs 543 Compression of marsh soil .... 1097 Conduit Trenches 773 Conveyor, see chap. 13 575 Bates belt conveyor on Chicago canal 985 belt 603 capacity 604 life of . . . ; 604, 708 for backfilling trenches 800 dam built with 608 long belt used at a quarry . . 607 iised on Lahontan Dam 611 Core Avail, requirements for earth dam 1149 Cost of earthwork, factors af- fecting 37 Cost keeping, method of, show- ing unit cost for each scraper gang 310 Counterforts of rammed earth. . 1309 Creek change, handling hard pan with wheel barrows . 171 Cross firing with elevating grader for highway 234 Culverts, cost of excavating on a canal project 947 Curb and pavement, excavation for 115 Curved trenches, use of steam shovel on 805 Cuts, see grading Cutting down railway grades . . 391 Dam, see chap. 20 1147 belt conveyor on Lahontan dam 611 boulder filled wire baskets used for 1208 Calaveras, slide on 1244 cinder built dam in Pa 1159 Cold Springs dam, Ore 1197 ' compacted by irrigation flood- ing 1172 constructed by cars and hy- druulicking 1236, 1238 conveyors handling material on 608 earth embankment with gravel facing 1213 electric shovel on 545 elevating gra-der work on ... 236 goats used for compacting . . . 1170 HiU View Reservoir 1206 hydraulic construction of ... 1058, 1059. 10*50. 1066, 1070, 1221, 1227, 1249, 1241 INDEX 1333 Dam Kachess lake dam 1202 Lahontan 1156 i-orto Rico irrigation service 1157 rolling cost at Belle Fourche 487 San Leandro 1152 scrapers and hydraulic exca- vation used on 1059 slides on 1243 shrinkage of 14, 1164 small dams for stock watering reservoirs 1163 spreading and rolling cost on 158 st Hovland tile ditcher JJ Hydraulic dredge JJJ building embankments with 1116 cost with in Mobile Harbor 721 handling very soft material 723 maximum depth reached by 721 pipe line for '41 elevators .1010, 1013, 1014, 1035. 1036 excavation, see chap. 18 1004 canal dug by ljjO carrying capacity of water . 1005 core-wall tronch dug by ... 845 dams built by hydraulickmg 1058, 1059. -1060, 1061, 1064, 1066, 1070 dam constructed of mine tailings 1066 Denny Hill regrade, Seattle 1081 ditches and flumes for 1009. 1017 duty of miners inch . . . 1013, 1027 filling trestles 1051 flumes for 1022, 1023, 1044, 1064, 1077 gravel mining cost . 1025 highway embankment built by 1055 hydraulic elevator plant . . . 1010 incline and giant 1013 land slide removed by 1048 movable flume for 1022 placer mining 1027 pressure boxes 1015 pumping sand throtigh spiral pipe line 1046 retaining hydraulic fill with sheer boards 1056 river banks graded with water jet 1036 sheerboards, lumber re- quired for 1079 simple timber flume for ... 1044 stripping by means of .... 1038, 1044, 1047 sluicing applied to a small job 1056 sluicing silt to reduce canal leakage 1083 water requirement of giant, sluice and elevator 1013 working placer gravel 1026 Hydraulic fill dams, design of . . 1220 retaining with hay and dirt embankments 1054 Hydraulic giants 1004 grading of Westover Terraces 1075 hopper dredge for Pacific coast 731 jet for levelling spoil banks . . 695 mining. p'P P lines for 1016 range in cost of 1032 Hydraulic giants stripping of gravel pit Hydraulicking, 1038 Abbot Brook dike 1240 Bear Creek dam 1227 Concully dam 1221 Panama Canal work done by . 1049 Somerset dam, Vt 1241 volume of water required for 1009 Importance of prospecting .... 41 Incline cableway 580 tipples used with steam shovels 513, 981 used with giant 1013 Insley wagon loader 195 Irrigation d'tches 903 preparing land for 164 Iron ore handled by steam shovel 459, 462 Jack blocks, steam shovel . . 427, 459 Jacobs guided line excavator . . 636 Jerk-line for handling teams . . 208 Jointed sounding rod 42 Jordan spreader, work with . . . 385 Junkin ditcher 917 K Kalamazoo extensable trench brace 862 Kaolin, definition of 3 Keystone traction excavator . . . 555 Kind of earth, effect on cost of excavation 39 King ditcher 921 L , Ladder dredge 704 belt conveyor used with .709, 711 filling trestle 708 formula for power required 705 long chutes used on . '. . . . . 710 record at Panama Canal. . . 714 wear of parts in sand 698 Land dredge 909, 919 Monighan walking exca- vator 924 Large revolving shovels 510 Laterite 3 Laundering device for gopher holes 149 Lead and haul 165 Lee wagon loader 194 Legality of methods of calculat- ing earthwork 23, 24 Length of haul, effect on cost of excavation 39 Levee, see also dike, chap. 21.. 1246 buck scraper work on 253 INDEX 1339 Levee cableway and dragline bucket used on 603, 1257 drag and wheel scraper costs compared on 295 dragline construction of 1252, 12.14 enlargement of 1251 hydraulic construction of, 1262, . 1265, 1267 location of 1247 machines for building 1255 sand core levees in California 1272 sections on Mississippi and Sacramento Rivers 1249 swell of newly excavated ma- terial in 10 Leveler, rectangular 160 Leveling farm land with tractors 159 ground after gold dredging. . 623 Life of barges, tow boats and dredges 753 of belt conveyor 604 of belt conveyor on dredge. . . 708 of cable on engine incline. ... 372 of iron plates and wood blocks in flume 1077 of main cable 586 of steel plates in flumes, 1025, 1031 Light railways on road work, 358, 359, 360 Lime for thawing frozen ground 141 Lloyd unloading machine 378 Loader, power scraper wagon loader 619 Loaders, wagon, see chap. 8 ... 230 for use with cars 192 Loading device for gopher holes 149 hopper for use with wagons. . 560 machine for surface or under- ground work 247 through traps 283 trailer, for dump wagons. . . . 245 Loam, weight of 3, 4 Location, effect on cost of earth- work 38 Locomotive, see also dinkey capacities of, on various grades 505 cranes used for trenching. . . 778 used as dragline excavator. 638 light, types of 352 Locomotives, repair cost of, at Panama 413 water and fuel consumption of 354 Loess, definition of 3 Long handled shovel 106 Loosening and shoveling. . . .94, 151 sticky clay 107 explosives used, for 126, 127 methods of 91 Loose rock, Am Ry. Eng. and Maint. W. Asso. classifica- tion 37 in classification of earth work 27 specification of 34 Macadam excavated by revolv- ing shovel 525 Maintenance of ditches and canals 974 Management of steam shovel work 43 1 Maney four-wheeled scraper. . . 312 Manganese steel steam shovel dippers 421 Marl, definition of 3 device for sampling 46 gouge 10.-, Marsh soil, compression of. ... 1097 trenching in, with Parsons excavator 84"> Marshy ground, method of building embankments over Martin ditcher and grader Mattock compared with pick. . . Mattresses for supporting high- way embankment over marsh . 1093 Measurement, legality of meth ods of 22, 23, 24 Mechanical flock of goats 1171 Methods and cost of hauling.. 226 of loosening 91 Military trenches . . 901 Mine haulage by electric loco- motives 364 Miners inch 1009 Mine tailings used in hydraulic fill dam .' 1066 Mining, cars used to handle special earth 344 coal, systems of haulage. .363. 364 clay, steam shovels in brick- yards 366, 455, 457, 516, 523 iron ore with steam shovel . . 459 marl, use of cars hauled by cables 371 shale, tramming system used in pit 369 sand and gravel, with steam shovel 422. 443, 446, 448 thawing gravel for placer mining 141, 143, 145 Monahan back-filling machine. . 892 walking excavator 924 Moore trenching machine 819 Mosquito elimination by blast- ing 129 Motor boat, cost of operating. . 759 Motor trucks, foundation exca- .vation with 539 Motor truck hauling industrial railway cars 348 wagon trains 210 Movable hopper for excavated material 191 Moving steam shovels 470, 472 Muck 3 dredging cost with orange peel 685 1340 INDEX Mud, weight of Muskeg Navigable canals 980 New York State Barge Canal. . 986 Oakland revolving bucket scraper 273 Ocean bars, cost of dredging ... 724 Oil-storage reservoir, embank ment for 1175 Orange Peel buckets 567 foundation excavation with. Rfi7 handling muck trenching with, 568, 569, 783, Ore, cost of shoveling steam shovel work in iron ore O'Rotrke method of excavating deep cuts to neat lines . . . Overhaul in classification .... Overhead conveyors 567 f.sr. 107 4,-?.) 740 892 821 845 115 4 70 Page scraper bucket 642 Park in Chicago filled by dredg- ing Parson's back-filling scraper. . . trench excavator work with Pavement and Curb, cost of hand excavation for, .... Peat 3, Peat bog, cost of borings in ... Percolation factor, determina- tion of for dams 1163 Permeability of concrete and puddle walls in earth dams 1151 Petrolithic gang rooter plow. . . 122 P. & H. tamping machine 900 trench excavators 820, 825 Pick and mattock compared. . . 94 Picking and shoveling 96 diagram showing possible yardage foundation excavation .... frozen ground hard pan railway culvert, excavation for 117 station work on railway grading 173 table of average excavation at various depths 113 table for rating 110 trenching costs 769, 771 Pile driver, cost of operation of 759 used for sounding 43 used for trench sheeting. . . 850 Pipe lines, hydraulic dredge. . . 720 hydraulic mining 1016 Placer mining 1020, 1027 112 220 155 109 Planking for dragline work over soft ground Platform for retaining earth from trenches wheel of caterpillar tractor. . Plow test 25, Plowing, cost of with tractor outfit 124, Plows,. cable operated ditching dynamometer test on light grading rooter weight of Pneumatic tamping Pole holes, device for digging in frozen ground 139, method of blasting Pontoons Portable derrick excavator . . . Position, effect on cost of earth- work Post hole diggers Post spade Potter trenching machine, cost with 813, Power consumption, electric draglines 660, 666, electric shovels required for ladder dredge.. ditches Power scrapers Bagley scraper on highway bottomless canal excavation with excavating gravel under wa- ter foundation excavation with. handling mud leveling ground after gold dredges stripping with 616, tower dragline excavator on canal ,. wagon loader Preparing land for irrigation. . Properties of earth, see chap. 1 Prospecting, see chap. 3 augers used for 61, cable drills used for importance of Prospecting, test pits for test trenches for Puddle placed in cofferdam by 645 771 219 34 119 125 120 927 123 121 121 120 901 140 132 743 620 38 80 105 815 952 54 5 705 904 615 617 619 627 627 631 618 62.1 999 619 164 1 41 65 82 41 83 pumping llir Puddling backfill Pulsometer pump Pumping costs on a sewer job 862, 863, Push scraper grading across slough 1215 896 863 864 260 Quantity, effect of, on cost of earthwork INDEX 1341 Quicksand ditching with explosives .... 937 drained by "bleeding" 880 excavated by freezing 869 grouting 869 trenching in, 820, 865, 868, 869, 877 R Rail clamp for steam shovel and cars 424 joints, flexible 426 Railroad ditches 965 Railway, see grading railway, also embankment ditches and locomotive crane shovels 515, 965 embankments 1098 grading with draglines 1115 piling a sliding cut 1289 slides, treatment of 1288 specifications for classification 29 Raising a railway embankment, cost 1136 Raking, cost of hand work ... 153 Ramming and rolling 157 Recommended practice in shovel operation 430 Record for ladder dredges .... 714 Rectangular, leveler 160 Reservoir cleaning by hydraul- icking 737. 1051 Reservoir embankment, built with concrete slope 1161 cost for settling basin 1181 cost of rolling at Forb's Hill 157 rolling slopes of 1178 shrinkage 16 special wagon for use on . . 1179 trimming at Forb's Hill 155 wheel scraper work on 280 Reservoir for oil storage 1175 Resistance to rolling friction . . . 352 Retaining walls 1307 Revetment of slopes. 1312 Revolving bucket scraper 273 Rifle pits 905 Road and railroad embank- ments, chap. 19 1087 Roadbed ditches 903 Road graders 320 used with tractor _ 327 Rocker double side dump car. . 3-38 Rock foundation excavations, specification 35 Rolled embankment, shrinking of 14, 17 Rolling 157 backfill 901 cost on Belle Fourche dam. . . 487 embankment at Yale Bowl. . . 121.8 friction, resistance to 352 puddle on reservoir embank- ment slopes 1178 shrinkage produced by, in top soil 15 tamping roller ..." 1090 Rooter plow 121 Roots, types of 86 Round point shovel 105 Rule for cost with carts 176 drag scrapers 258 elevating grader 231 fresno scrapers . . 262 horse-drawn cars 346 wagons 186 wheelbarrows 169 wheel scrapers 276 8 Sampler for marl 46 Samples, means of obtaining 43, 45 Sand 4 Sand core levees 12 7 2 excavated with wheelbarrows 116 excavated in trench with or- ange peel bucket 569 steam shovel work in sand and gravel. . .440, 442, 443, 446, 448 transported through pipe with an ejector 1014 trenching in 783 weight of 5 Saps 904 Screen for use with wagons. . . 192 Scientific management of trench- ing 100 Scoop conveyor for loading and piling 249 car for handling railway slides 1297 diamond point, shovel 106 Scow bridge used for building embankment 1121 Scows, cost, life, repairs, 753 method of measuring load by displacement 763 Scraper, see buck scraper, drag scraper, fresno scraper, etc., chap. 9 250 buck 250 Scraper, bucket cableway 59") cableway excavator 589 ditching with 251, 937 drag . 254 drag and wheel, grading rail- way 1140 for lowering crest of sand bars 752 for pushing dirt ahead of team 259 side 252 tongue 251 used with belt conveyor on foundation work 604 work, cost keeping for 310 Sea-going dredges 721, 731 Season of year, effect of, on cost of earthwork 38 Sectional track for dragline excavator 646 Seeding slopes 156 Seepage losses in irrigation canals 906 1342 INDEX Sewer, trenching for 711, Shale -. handled by trenching ma- chines weight of .- Sheerboards, lumber required for used for hydraulic fills 1056, Sheeting and bracing trenches. and bracing under steam shovels cost of cutting with augers driving S5> horizontal machine for pulling removing Shoreing in deep sewer Shoveling clay 115, 116, ore rate of table of cost Shovels, design of size of types of 104, 105, Shrinkage . . 8, 11, 12, 14. 16, 17, and subsidence, method of dis- tinguishing . . allowance for with frozen backfill clay 13, Cold Springs dam conclusions on 17, data on weight of earth un- der various conditions in the Tabeaud dam due to removal of stumps. . . effect of water in clay embankment material handled in wheel- barrows method of allowing for. .497, Side dump cars Side scraper Silt, dredging with ladder dredge removed from canal by hy- draulicking Single track revolving shovels. . Size of hand shovels of particles of earth Skip dumping device for cable- way . . . ._ Skips foundation excavation with handled by trolley cableway.. Slide, Calaveras dam "... controlled by piling clay held by drainage tun- nels effect of rainfall on movement of electric shovel working on.. Hudson, N. Y Mount Yernon Portland, Ore. 780 Slide 4 reconstruction of at Charmes dam 1243 837 removed by hydraulicking. . . 1048 5 Slides at Bull's Bridge Hydro Electric Plant . .' 1280 1079 cause and cure of . 1277 1117 European railway practice for 846 prevention of 1306 held by piles 1298, 1300 791 in N. P. Ry. cuts 1296 848 Panama canal 1283 853 prevention of on Chicago 851 Canal 1282 848 railway practice for treatment 853 of 1288 852 scoop car for handling 1297 790 stopped by use of explosives. 1305 96 Sling for handling wagon bodies 118 with derricks 184 107 Slips, and Slides, see chap. 22. 1276 106 control of on English railway 1321 97 prevention on railway 1290 103 treatment of a wet cut for . . . 1294 98 Slipping prevented on Germaii 106 ry. embankment by drain- H64 age 1325 Slope drainage 1312 1088 protection, earth dams 1151 trimmer for irrigation canals 907 trimming machine 1178 14 Slopes of 1 to 1 cut with dipper 1199 dredge 956 18 Sloping canal banks, boat for 991 Sluicing, see chap. 18 1004 material from cars 384 1169 sand and gravel in steel lined flumes 1023 silt to reduce canal leakage.. 1083 9 Small revolving shovels 516 Smoothing devices, for prepar- ing land for irrigation... 160 and leveling farm land 159 337 machines '. .' 322 252 Snatch teams 188 Soft material, see also wet ma- 705 terial 119 canal excavation in, by ca- bleway . .596. 600 515 dumping sticky material from cars .' . 382 handled with power scraper 618 hydraulic dredge in very 587 soft mud 723 spade and hay knife in wet 558 soil ' 908 trenching in muck 858 trenching in salt marsh. ... 880 widening wheels of elevating grader on account of. ... 234 1292 Soil, kinds of 1 sampler for 45 1284 Solid Rock, specifications for in o"9 classification 26, 34. 37 1279 Sounding 42 1279 rods, for, 42, 43 1284 Spades, types of 105 INDEX 1343 Specific gravity Specifications for classifica- tion ... 26, 29, 30, 31, 34, 35, for steam shovel construction for trenching and backfilling. Spoil banks leveled with hy- draulic jet Spreaders Spreading and rolling, see chap. Belle Fourche dam Cold Springs dam earth dam at Springfield, Mass Hill View Reservoir Kachess Lake dam Tabeaud dam 158, embankment with Jordan spreader Sprinkling, see also watering. . Spuds, vertical and bank com- pared Square point shovel sounding rod Stanley tamping machine .... Station work on railway grad- ing Steam jets, thawing for steam shovel Steam shovel, accident and cost of repairs on railway job analysis of cost of work. . . ballast handling with Belle Fourche dam, work on 485, Bishop's derrick excavator., canal excavation, method of using on canal excavation with, 493, 994 discussion on cost of work. . cost formula cut of two lifts in one .... device for lifting jack blocks dippers 420, double ditcher train dismantling electrically operated . . . .541, filling trestle, flexible rail joint foundation excavation, with 524 grade reduction with, 480 grading highway, 533, grading railway, 452, 457, 464, 474, 475, 487, 502, 507, 537 grading street handling high output with hints on horizontal crowding motion of small shovel 518, incline tipple used with on canal iron ore handled by 5 Steam Shovel Keystone traction excavator 555 37 large revolving 510 428 loading motor trucks ..... 539 &5o loading wagons 509 macadam excavated by .... 525 695 management of 434 384 method of supporting in trenching 793 mining clay with 516 mining sand and gravel 1199 with 442, 443, 446, 448 mounted on hull for dredg- 1188 ing 693, 694 1207 moving 470, 472, 474 120.1 output on Hill View Reser- 1168 voir 501 output of large stripping 385 shovel 511 157 records on Panama Canal. . 495 prices of 418, 507 672 pyramidal jack blocks for . . 459 105 rail clamp for shovel and 43 cars 424 899 recommended practice in op- eration 430 173 repair costs, Panama Canal. 413 revolving shovels, work with 143 515, 516, 520, 523, 526 specifications for construc- 489 tion of 428 403 specimen cost of 400 1132 standard classification of ex- pense 437 1191 stripping with 503 554 Thew revolving shovel . .522, 531 throwing track for 471 396 trenching with, 786, 795, 797, 804 499 trenching with on curved trenches 805 400 types of 387 405 widening cuts 389 399 work in clay 451 427 Steam shovel work in iron ore. 459 421 work in sand and gravel. . . 440 515 Steam thawing 140, 141, 147 468 Steam tractor plowing 124 543 Stock pile work with steam 477 shovel 462, 467 426 Stockton ditcher 914 519 Stone grappl>rs 678 Storage drum for dredge cable 681 319, 479 tripping, breaking frozen banks 149 coal with elevating graders. . 239 538 dragline costs on coal beds. . 666 455 gravel pit with elevating grad- 498 ers 237 hydraulic, 103S, 1044, 1046, 1047 535 output of large shovel 511 387 possibilities with 300-ton shovel 511 495 power scraper used for . .616, 628 466 steam shovel work in anthra- cite region 503 523 Stumps, amount of dynamite for blasting '91 513 loss of material due to grub- 462 bing 89 534, 453, 496, 1344 INDEX Subsidence, calculating amount of 1088 investigations of for railway valuation 1099, 1101 method of distinguishing from shrinkage of levees 1088 Sub-soil 4 Suction dredges 718 Supporting construction track on ice 1120 Surface ditches 904 Surfacing and dressing earth- work 153 Suspension bridge for making fills 1100, 1113 Swamp, see tilling low ground excavating in freezing weather 119 Swelling of dredged material. . . 17 of newly excavated material . . 10 Switch for narrow gauge tracks 339 Tabeaud dam 1165 Tamping clay 897 P. & H. machine for 900 pneumatic 901, 1130 roller for 1090 Stanley machine for 899 Teams, handling with jerk line 208 work of 187 Telegraph shovel 106 Telpher system 586 Template ditch excavators, 909, 915 Test pitting 83 Test trenches 83 Thawing, frozen gravel 141 ground for trenching 147 lime used for 141 steam pipes used for 140 Thew revolving shovel . . . .522, 531 Three-horse eveners 307 Through cut with steam shovel 394 Throwing track 471 Tile drainage, Buckeye traction ditcher, cost with 840 cost in California 777 Tile drains, trenching for .... 775 scoop 775 Timbering, in trenches . . . .831, 846 Tongue scraper 251 Top soil 4 shrinkage of 15 stripping with power scraper 628 Tow boats, cost, life, repairs. . 753 Tower, cableway 581 dragline excavator 999 scraper excavator 594 Track, contractors switch for.. 339 throwing car 339 Tractor engine hauling elevating grader 231 with 4 driving wheels .... 215 plowing outfits 125 Tractive force, dinkeys 350 resistance, mine cars 342 Tractive resistance plows 123 Tractor, caterpillar 218 grading 827 leveling farm land 169 plowing 123 pulling elevating grader .... 243 road work with 333 semi trailer type for hauling 216 types of 215 Trailers, for loading wagons.. 245 for motor truck haulage .... 215 Transportation cost of men. tools and supplies on rail- way grading 1130 formula for 226 applied to scraper work. . . 301 Trap for loading cars with dump wagons 240 for loading wagons, 199, 202, 283 Tree planting in blasted holes 128 Trench and ditch definitions. . 766 Trench brace, Bottomley, .... 860 Kalamazoo 862 cableways 807 excavator, Buckeye traction ditcher 839 Hovland ditcher 841 Parsons 821 P. & H 825 sheeting, handling under a shovel 466 Trenches, backfilling 884 under paved streets 885 Trenching, see chap. 15 766 as means of prospecting .... 83 Austin excavators ..833, 834, 835 837, 838 backfilling wagon for 802 Buckeye traction ditcher, 839, 840 841 cableways on sewe,r work. . . . 808 Carson machine for 810, 830 chisel excavator for frozen ground 146 clam shell bucket used for 571 783 cost with orange peel bucket 568, 569, 783 derrick used for, 778, 779, 780 782, 783 dragline bucket used for, 647, 778 786, 869, 877 driving sheet piles 850 electric conduit work 774 hand excavation, 117, 221, 767, 769 771, 772, 773, 776 in quicksand 877 in successive steps 760 hydraulic excavation . . . .845, 880 method of supporting small shovels 793 Moore machine 819 muck soil 858 orange peel bucket in quick- sand . 870 INDEX 1345 Trenching overhead conveyors 807, 820 Parsons excavator 824, 845 P & H. machine 820, 828 Potter machine, 813, 815, 816, 817 pumping 8C2, 86i quicksand 865, 868 rapid work with small steam shovel 804 revolving shovel 793 scientific management of .... 100 sheeting, see also under sheet- ing 846 cost of Wakefield piling. . . 853 under steam shovel 791 specifications for 886 steam shovel, hints on 790 work on curved trenches. . 805 work with, 786, 795, 796, 797, 800 804, 886 tile drains 775, 863 unwatering by "bleeding" 865, 872 with special machines 807 with three types of buckets and locomotive crane 565 Trestle filling, hydraulicking material on railway 1051 ladder dredge used for. ... 708 method of filling a 75-foot trestle 1139 steam shovel work on 477 Trestles, carpenter work on ... 1105 dumping 1102, 1103, 1104 floating, for constructing em- bankment 1123 movable 1105 temporary 1102 wire rope 1106 Trimming 154 and dressing frozen ground.. 155 and seeding slopes 156 cost on railway grading .... 266 cuts and embankments 40 hand work on athletic field . . 152 machine for slopes 1178 river banks with water jet. . . 1036 slopes of oil storage reservoir 1175 slopes of irrigation canals. . . 907 subgrade 156 Troughs, canvas, for carrying sewer in trench 831 Trucks handling excavation . . . 209 Trunnion buckets on foundation excavation 560 Tugs, used with dredges . . .747, 759 Tunnel, cost of in gravel 1077 driven to stop slide 1285, 1292 handling stickey clay in 107 relieving pressure on with power scraper 622 Turntable, for dumping motor trucks 212 Types of contractors' cars .... 335 light locomotives 352 roots 86 steam shovels 387 tractors . . 215 Types of wagons 179 wheelbarrows 165 U Undercutting frozen ground. . . 139 Unloader, plow, cables, method of handling 375 Unloaders, car 372 Unloading, cars by sluicing. ... 384 in small space 382 machine, Lloyd 378 Panama Canal 374 Unwatering trench in wet sand 785 Vacuum pump, delivering dredged materials 682 Vertical and bank spuds, com- pared 672 Vertical bank, greatest height of 8 Voids in dry earth 6 W Wachusett dam, shrinkage of embankment 16 Wacke , 4 Wagon, bottom dump 180 center dump 182 end dump 180 gravel screen for use with. . . 192 high cost of work with 205 loader, see chap. 8 230 for use on cars 192 used with wheel scrapers.. 283 power scraper type of 619 loading trailer ,. 245 sling for handling "wagon bodies 184 special backfilling 802 special dump 181 train haulage with motor trucks 210 work 184, 187, 197, 198 Wagons, building dike 199 dump boxes handled by der- ricks " 182 dumped with derricks 195 grading railway in freezing weather 207 roadway for 189 rule for finding cost with ... 186 snatch teams used with 188 table of cost of hauling .... 228 trap for loading by drag scrapers . . " 197 types of 179 Wakefield sheet piling 853 Walking dredge 922 traction for dragline exca- vator 633 Wash borings, 46, 48, 50, 51, 52, 55 56, 58, 59. 1346 INDEX Wash Borings conclusions from experience at Ashokan reservoir .... 63 instructions for inspectors on Catskill aqueduct .... 61 Water and fuel consumption of locomotives 354 carrying capacity of 1005 main and conduit trenches.. 773 Watering, see also sprinkling cost at Belle Fourche dam . . . 487 Wave fence for dam protection 1163 Waterloo backfiller 893 Weeds, elimination of in irriga- tion canals 978 Weeks two line bucket 641 Weight of earth, effect of depth on 5 under various conditions in Tabeaud dam 1169 of soils 4 Westover Terraces, hydraulic grading of 1075 Wet foundation excavation, specification of 35 Wet material, see also soft ma- terial ditching with dynamite. .131, 132 loosening and shoveling stickey clay 107 Widening embankments by va- r.ious methods 1123 railway cuts 389 wheels of elevating grader . . . 234 Wiring, method of connecting blast holes in ditching 135 Wheelbarrows, capacity of ... 169 compared to carts 170 cost with 168 end dumping 167 Wheelbarrows grading railway 1143 loading into cars Ifi9 rule for finding cost with . . 169 station work on railway grading 173 types of 165 work with 116, 170 W'heel excavators 909, 910 scrapers, canal excavation with 282 cost analyzed 300 costs, compared to costs with cars . . . . 347 compared to costs with drag scrapers 295 curves showing costs with . . 302 foundation excavation with. . . 308 grading highway 291 grading, railway, 281, 284, 286, 288, 291, 297, 305 hints on handling 277 loading wagons through a trap 283 reservoir embankment built with 280 work with in freezing weather 289 Wheeled planer for smoothing land 163 Wood and steel sheeting for trenches 848 Work of teams 187 World's dredging record, Pan- ama Canal . 704 Y Yale Bowl, embankment for ... 1217 THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW AN INITIAL FINE OF 25 CENTS WILL BE ASSESSED FOR FAILURE TO RETURN THIS BOOK ON THE DATE DUE. 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