IRLF 
 
 3Dfi 
 
GIFT OF 
 
The Engineer 
 in Field and Office 
 
 New Ideas for Securing Uncom- 
 monly Quick, Accurate and 
 Economical Results. Reprinted 
 from the Engineering News-Record. 
 
 ENGINEERING NEWS-RECORD 
 
 Tenth Avenue at Thirty -Sixth Street 
 
 New York 
 
 1918 
 
Copyright 1918 
 McGraw-Hill Publishing Co., Inc. 
 
PREFACE 
 
 Civil Engineering is an art of which it can never be said that 
 it "stands still." It keeps pace with human needs and human 
 necessities are ever expanding. 
 
 Every year every month almost every week witnesses fresh 
 demands for more conveniences, quicker transportation, more effec- 
 tive safeguards for public health and comfort. 
 
 In meeting these demands, civil engineers are, happily, most 
 efficient. The profession is continually making new discoveries 
 putting forth new inventions suggesting new applications of 
 former theories devising more effective designs improving upon 
 the old methods. 
 
 Recognizing its obligations to the field it serves, the Enginering 
 News-Record not only opens its columns freely to the authors and 
 originators of these new ideas so that their experiences may be 
 passed along for the benefit of others, but is continually seeking out 
 the new and helpful. 
 
 These advances thus become incorporated into the common prac- 
 tice long before they get into the books or become part of the 
 teachings of the schools. 
 
 The best of the new ideas which have recently appeared in the 
 News-Record have been collected for this volume. 
 
 The editors feel that many of them are too valuable to remain 
 hidden in the files of a periodical, even of a journal whose back 
 numbers are so frequently consulted as are those of the Engineering 
 News-Record. 
 
 They are confident that in this accessible and permanent form 
 this new material will be helpful to every engineer who wishes his 
 work to be abreast of the times. It is Civil Engineering brought 
 up to date. 
 
 For the most part, in the case of the contributed articles we 
 have let the engineers tell their own story. But little editorial 
 responsibility has been assumed, beyond the elimination of occa- 
 sional personal and local references in the articles as they originally 
 appeared in the columns of the Engineering News-Record. The mere 
 fact that they were admitted to these columns is sufficient guarantee 
 of their good faith and of the editors' judgment of their worth as 
 contributions to current practice. 
 
 380101 
 
CONTENTS 
 
 I Of Value to the Highway Engineer 
 
 II Interesting Lights on Building Construction-Theory, Design 
 and Methods 
 
 III Some Capital Things in Foundation Work 
 IV New Ideas in Designing and Building Bridges and Dams 
 V Helps for Municipal and County Engineers 
 
 VI Present-Day Water-Works Construction, Maintenance, Op- 
 eration and Repairs 
 
 VII Interesting Solutions of Problems in Sewer Construction 
 
 VIII What Engineers are Doing in the Fields of Flood Control, 
 Irrigation and Hydraulics 
 
 IX Practical Pointers for Railway Civil Engineers 
 X Helpful Suggestions from Recent Concrete Construction 
 XI Results of Recent Tests in the Laboratory 
 XII Practical Hints for the Surveyor 
 XIII Draftsmen's Kinks 
 XIV Simple and Effective Methods for Filing Engineering Data 
 
The Engineer in Field and Office 
 Of Value to the Highway Engineer 
 
 Traction Is a Straight-Line Function of Tire Width 
 
 It has been recognized for many years that the narrow steel tire 
 is enormously destructive to earth and gravel roads. The formation 
 of a rut begins practically with the passage of the first vehicle 
 improperly equipped. The U. S. Department of Agriculture has 
 shown that the effort necessary to draw a certain load is an inverse 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 ** 
 
 
 
 
 
 
 
 
 
 
 
 *** 
 
 ^ 
 
 ** 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 ^ 
 
 ^ 
 
 
 
 
 
 
 
 
 
 
 
 x 
 
 <^ 
 
 ' 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 200 300 400 SOO 600 700 800 SOL 
 
 RDunds \\feight (Gross Load) 
 Per lineal inch width oFftre. 
 
 Graph Shows Uniformity of Test Conditions 
 
 function of the tire width, and in this manner forwards another 
 argument against excessive load concentrations on the road surface. 
 The accompanying curve is plotted from data obtained under 
 similar conditions of moisture and atmosphere. The earth road was 
 plowed, graded and rolled between each series of tests, and its 
 condition throughout the investigation was probably as uniform as 
 the nature of the test warranted. A gross wagon load of 5000 
 Ib. was maintained, the tire width being varied from U in. to 
 6 in. 
 
The Engineer in Field and Office 
 
 The unit draft decreases directly as the weight per inch width 
 of tire decreases, until a weight of 250 Ib. per inch of tire is 
 reached, as is indicated by the curve. The draft for a 6-in. tire is 
 larger than that for a 5-in. tire. This was uniformly true, and 
 indicates that there is not only nothing gained by increasing the 
 width beyond a certain point, but there may be a positive disad- 
 vantage in so doing. 
 
 Handling Hot Oil on Maintenance 
 BY H. M. LUKENS 
 
 The Los Angeles County Highway Department has a unique 
 system of heating and distributing oil in the maintenance of its 
 paved ways. The oil is too cold for use when it reaches the job in 
 trucks from the main depot. It is poured into buckets that have 
 previously been arranged in two rows with another row on top. 
 A portable distillate and water burner has proved very efficient. 
 As many as 80 buckets of oil can be heated to 500 F. in about 15 
 min. About 15 or 20 gal. of oil at this temperature is placed in 
 the hand oiler for direct application to the patch or street. 
 
 The hand oiler is made of sheet iron, with a boiler about 2$ 
 ft. in diameter and about 3i ft. high. Inside this boiler hangs a 
 cast-iron pot of about 20 gal. capacity, the intervening space between 
 the pot and the boiler being used as a firebox. This apparatus 
 is so suspended on two iron wheels that the center of gravity 
 is low enough to keep the boiler upright. On one side is riveted 
 an iron handle with which to move it, and opposite and on top 
 of the boiler is the hand crank for the oil pump, which is fastened 
 to the bottom of the oil pot. The pump, of the rotary type, 
 is driven by sprocket and chain from the hand crank and is capable 
 of developing 6 to 10 Ib. pressure per square inch. To the pump 
 is attached 20 ft. of f-in. metallic hose with a piece of f-in. 
 pipe 3i ft. long at the discharge end. This end is plugged so 
 that under pressure a spray is formed which may be regulated by a 
 throttle. The maximum capacity of the machine is about 125 gal. 
 per hour. 
 
 It has been found from experience that best results are had 
 from heating the oil to the desired temperature in the buckets and 
 using it in the hand oiler without any additional fire in the firebox. 
 Fire in the oiler causes the bottom of the oil pot to cake up, which 
 in time breaks loose and clogs the pump. 
 
Highway Engineering 
 
 Concealed Wood Strips for Transverse Joints 
 
 Many of the troubles attending the use of transverse joints 
 in concrete pavements can be avoided by installing at the bottom 
 of the slab a I -in. wooden strip of about half the depth of the 
 concrete. In this manner planes of weakness where transverse 
 cracking may concentrate, are definitely located. 
 
 Four joints of this type were installed in 1915, and withstood 
 the following winter without cracking, although fine hair cracks 
 appeared in June, 1916. These cracks were very narrow and 
 followed a zigzag line around the individual stones of the concrete 
 directly over the wooden strip. The zigzag cracks nowhere departed 
 more than 2 in. from a straight line. These cracks were exposed 
 to traffic all summer, and no spalling of any kind has been noticed. 
 
 The result was so satisfactory that in 1916 10 consecutive joints 
 of the same type were installed on each of two roads. These 
 have gone through one winter and are now in excellent shape. 
 Fine hair cracks have appeared over most of the joints, but the 
 fact that the pavement has not yet cracked over a few indicates 
 that the slabs might have been made somewhat longer than 30 
 ft. in this particular locality. In no case has the pavement cracked, 
 except over the wooden strips. 
 
 The advantages obtained by this method over other types of 
 joints are: (1) No spalling along the joints; (2) no interference 
 with scr ceding or floating, and a much smoother pavement; (3) 
 the joints are cheaper and easier to install, the wood may be of 
 cheap material and need not be creosoted; (4) better appearance of 
 the road. 
 
 The advantages of this method over nol joints at all are 
 that by choosing the proper length of slab to correspond to the 
 width of pavement and to climatic conditions the cracks will 
 be minimized and will run square across the pavement at regular 
 intervals instead of occurring haphazard and running in every 
 direction. 
 
 It is absolutely necessary that the top of the joint be kept 
 below the surface of the slab a sufficient distance to give body 
 enough to the concrete over it to prevent spalling. This minimum 
 depth has not yet been definitely determined, but from observations 
 already made, a distance of 2i in. near the edges and 3 in. near 
 the center of the pavement seems to work out very well. Should 
 this distance be much greater, it probably would necessitate decreas- 
 ing the length of the slab in order to insure the cracking at the 
 joints only. 
 
The Engineer in Field and Office 
 
 A simple way to prevent the wooden joints floating up through 
 the concrete is to drive short pegs at intervals of about 7 ft. across 
 the road and nail through the strip into the pegs. Bent wires 
 hooked over the joint would answer the same purpose. The strips 
 should be installed by means of a taper installing board in the 
 usual manner. 
 
 Exact Wear of Concrete Pavements Measured 
 
 BY A. N. JOHNSON 
 
 Consulting Highway Engineer, Portland Cement Association, 
 
 Chicago 
 
 The usual methods that have been devised for measuring the 
 wear of macadam roads are open to considerable error, aside from 
 usually being rather clumsy, but the method here proposed over- 
 comes many difficulties and is also extremely simple and convenient. 
 A drill hole i in. in diameter is made in the pavement. In the case 
 of a concrete pavement it may be 2 or 2 in. in depth. In the 
 
 <- .......... -r ..... 
 
 & 
 
 MachmeFvced Steel 
 
 -Flat Sea te 
 
 6"- ........... * 
 
 sFine Thread 
 
 Surface 
 fofPare/Tjent 
 
 efe- 
 
 5 "%"Diarr>. Copper P/ug 
 ^CementGrout 
 
 With This Device Wear of Concrete Can Be Easily and 
 Accurately Measured 
 
 bottom of the drill hole is set a copper plug about I in. long, with 
 its top made semi-spherical. The plug is embedded in the hole 
 with cement paste. A short steel scale divided into inches and 
 hundreds, small enough to be placed in the drill hole, is provided. 
 At its end is a small button with conical undersurface, which is 
 to rest on the spherical end of the copper plug. The hole is filled 
 with a wood plug, left flush with the surface, which is to be 
 removed when readings are to be made. 
 
Highway Engineering 
 
 A convenient method of measuring is to have a U-shaped handle, 
 which will span about 6 in., having flat ends on the legs. Drawn 
 between the supports is a tightly stretched thin thread or wire 
 1 in. from the surface of the pavement. This is to be held so 
 that the thread will be over the center of the drill hole. The 
 flat ends of the legs rest on the pavement surface and the measure- 
 ments are made to the thread. The thread may first be placed 
 longitudinally with respect to the pavement, then transversely, and 
 in as many other positions as desired. 
 
 Grasses To Protect Road Embankments 
 
 BY W. C. BUETOW 
 Division Engineer, Wisconsin Highway Commission, La Force, Wis. 
 
 Much damage to embankments and slopes that cannot be 
 prevented even by the provision of proper drainage and keeping 
 cattle from trampling the slopes can be taken care of by the planting 
 of well-chosen grass, which should be properly cared for until a 
 mat or blanket has formed. 
 
 Grasses do not form a mat or blanket very quickly, due to the 
 variance of the climatic conditions. The action of frost is the most 
 disturbing factor, and on account of the depth of its penetration 
 the upper stratum of the bank is kept in a loosened state that is 
 very susceptible to the spring rains. 
 
 When selecting grasses to be planted on the slopes, it should be 
 kept in mind, therefore, that a grass with a good system of roots 
 is to be used, as well as one able to withstand the hot rays of the 
 sun. Grasses that will grow on a sunny bank probably will not 
 take root and form a mat on the shaded slopes, in which case a 
 different kind of grass is necessary. 
 
 The protection to the bank lies almost wholly in the ability of 
 the roots to interweave so minutely as to form a system to reinforce 
 the surface stratum. Hungarian brome grass, Canadian blue grass, 
 fescue grasses and Western wheat grass are good to plant. In 
 many cases sod is handy to get and, when properly cut and placed, 
 offers very good protection. The sods must be held in place by 
 wooden pegs until the grass has taken root. 
 
 Seeding and planting are equally successful when conducted 
 properly. The surface in each case must be prepared in order to 
 make it at all conducive to a good growth. The seed cannot be 
 merely distributed on the slope and left with the hope that it will 
 catch. If necessary, the ground should be manured before any 
 seeding is done and if a sandy slope is treated, the surface must be 
 
The Engineer in Field and Office 
 
 protected from the wind with straw or brush until the grasses 
 are able to withstand the elements. 
 
 Different kinds of soil require a certain kind of grass or a 
 combination of several kinds. For shaded places a combination of 
 Kentucky blue grass, wood meadow grass, crested dog's tail and 
 various leaved fescues are well adapted. 
 
 Clay soils can be treated with a mixture of Kentucky blue grass, 
 English rye and fancy red top. The rye grass gives an early quick 
 result, the red top makes a bottom grass, and the blue grass is 
 the permanent feature. 
 
 Sandy soils require a quickly growing binding grass that will 
 withstand the drought. Creeping bent, Rhode Island bent and 
 fine-leaved fescue are grasses that answer this purpose. Western 
 wheat grass has unusual ability to grow on the sunny side of an 
 embankment. Creeping bent, Canada and Kentucky blue grass and 
 crested dog's tail are quick growing, deep-rooting grasses that will 
 bind the soil until such time as the more permanent grasses are in 
 possession. Sweet clover and creeping honeysuckle are recommended 
 for planting in cuts. 
 
 Dump Road Drags Before Pulling Across 
 Railroad Crossings 
 
 Men operating road drags should dump their drags or unhook 
 one end of the drag chain and pull the drag endwise whenever a 
 railroad crossing must be crossed, according to the "Bulletin" of 
 the Iowa State Highway Commission. Railroad men are complaining 
 that this precaution is not being taken. They have appealed to the 
 commission to do all in its power to get dragmen to watch this point. 
 Pulling the drag across the tracks in the usual manner leaves the 
 space between the rails and the planking on each side filled with 
 dirt and small stones. Each passing train packs this material down, 
 and the next dragging fills the space again. This continues with 
 every dragging ; and if a good-sized hard hand-stone becomes packed 
 in this space, there is the best possible situation developed for a 
 derailment. Derailments of hand cars and motor cars are of almost 
 daily occurrence because they are not heavy enough to crush the 
 dirt and stone sufficiently to allow the wheels to retain a safe hold 
 on the rails. There have been many derailments of trains traceable 
 to this cause, but so far, no serious wrecks. 
 
Highway Engineering 
 
 A New Subgrader Design 
 
 Instead of the usual scraper blade at right angles to the center 
 line of the road, a new subgrader used in California has four pairs 
 of plow-shaped blades arranged to balance the thrust. These are 
 set at an angle with the center line, and as a result the tendency 
 to pile up earth ahead of the grader is avoided. This feature makes 
 possible more work of a satisfactory character with fewer laborers 
 than is obtainable from the ordinary type of subgrader. 
 
 A feature of the new device is the quadrant and lever regulation 
 of the blade, whereby the height of the blade can be adjusted 
 without the use of special tools. This arrangement also permits 
 raising the blades until the scraper rests on a central circular 
 plate, or turntable, in which position it can be easily swung parallel 
 to the center line of the road to allow space for passing vehicles, 
 or so that it may be trundled off the graded roadbed. Angle irons 
 are provided as guides to keep the wheels on the header. 
 
 Since the blades shear through the material rather than pile it 
 up ahead, depressions in the subgrade are avoided to a great extent. 
 The grade may be controlled to a nicety on account of the clean 
 action of the plow blade, and thus a considerable saving in concrete 
 is effected. It is notable that the setting of the blade at acute 
 angles has reduced the tractive effort below that required by the 
 ordinary grader. The most effective work has been done when the 
 grader is hauled by cables running from its extreme ends to the 
 tractor, which is kept about 30 ft. in advance. 
 
 Earth-Road Maintenance by s Contract 
 
 BY C. S. BENNETT 
 State Engineer and Inspector, Greenup, Ky. 
 
 After considering various methods of maintenance for the new 
 roads of Greenup County, Ky., it was decided to adopt the contract 
 method. The specifications as finally drawn up embody provisions 
 for dragging, cleaning ditches and culverts, cutting weeds on the 
 county's right-of-way, maintaining a crown, etc. Bids were then 
 asked for and work on each section was let to the lowest responsible 
 bidder. Mileage was considered the basis for payment, while slides 
 and washouts were paid for by the cubic yard. The work was 
 usually let in five-mile sections. 
 
 A road drag, two drag scrapers, one wheel scraper, shovels, and 
 mattocks, were furnished to each contractor, being charged against 
 him with the provision that at the expiration of his contract he 
 account for all tools supplied to him. In addition, two large blade 
 
8 The Engineer in Field and Office 
 
 road graders were purchased by the county, being lent to the various 
 contractors as they were needed in shaping up the roads in the 
 spring season. A contractor was required to own at least one team. 
 
 The work was under the supervision of the county road engineer, 
 who notified the contractors when they were to drag the roads and 
 when to cut the weeds on the county's right-of-way. He also issued 
 to them instructions as to other details of the work. 
 
 Payments were made quarterly, the payments being so distributed 
 as to make a maximum payment fall at a time when the greatest 
 amount of maintenance was necessary. Thus, for instance, a 
 contract dated Jan. 1, 1916, stated that payments would be made to 
 the contractors as follows: 20% Apr. 1; 40% July 1; 15% Sept. 1 
 and 25% Dec. 31. The maximum payment, 40%, was made at the 
 end of the spring season, during which time the greatest amount 
 of work is necessary to keep the roads in condition. In addition, 
 each contractor was required to give bond for the faithful perform- 
 ance of the work called for in his contract. Strict adherence to the 
 terms of the contract, especially in regard to dragging the roads, 
 was insisted upon. 
 
 The cost of maintenance on seven sections of road for the year 
 1916 is as follows: 
 
 Length, 
 Contract No. Miles 
 
 45 Dl 4 
 
 45 C 1 5 
 
 45 Gl 5 
 
 45 G 2 5 
 
 45 E 1 3 
 
 45 A 1 5 
 
 45 G 3 3 
 
 From a comparison made with similar work done in other 
 counties under various other methods, the writer is led to believe 
 that the contract method, properly looked after, is the cheapest 
 method of continuous maintenance for earth roads. 
 
 Peaked Subgrade Provides Better Underdrainage 
 
 A concrete or brick slab laid with a flat bottom upon a flat 
 subgrade affords no possibility for underdrainage. As a result, 
 seepage through the pavement at various points such as expansion 
 joints, along car rails, and through semiporous spots keeps the 
 subgrade moist and affords a good chance for frost upheavals with 
 the resultant cracking of the rigid surface. While there is but 
 slight importance attached to such seepage if the construction is 
 on a sandy or porous soil, a clay or heavy soil brings about conditions 
 which cannot be disregarded. 
 
 Bid per 
 
 Bid per 
 
 Bid per 
 
 Total Cost 
 
 Milerper 
 Maintenance 
 
 Cubic Yard 
 for Earth 
 
 Cubic Yard 
 for Rock 
 
 Mife 
 
 $45.00 
 
 0.35 
 
 0.40 
 
 $48.50 
 
 56.00 
 
 0.37 
 
 0.37 
 
 61.05 
 
 40.00 
 
 0,24 
 
 0.35 
 
 40.35 
 
 60.00 
 
 0.30 
 
 0.30 
 
 76.22 
 
 53.00 
 
 0.35 
 
 0.40 
 
 53.00 
 
 100.00 
 
 0.20 
 
 0.50 
 
 138.00 
 
 75.00 
 
 0.35 
 
 0.60 
 
 75.00 
 
Highway Engineering 
 
 9 
 
 The ordinary precaution of laying a slab with a crowned bottom 
 upon a crowned subgrade does not entirely alleviate these conditions, 
 as the slab is laid directly upon the heavy soil, filling every crevice 
 and blocking a free movement of the water from under the crust. 
 
 ^ * 
 
 on each Side offibacf 
 c*ndfill.edwt+h crushed 
 Stone or Grave/ 
 
 Shpe of -Side Drains %'per-fl; 
 
 Peaked Subgrade Brought Level with Sand or Gravel 
 Affords Best Possible Drainage 
 
 The newer specifications, which require 2 or 3 in. of sand to be laid 
 upon the flat subgrade, and upon this sand bed to lay a flat-bottomed 
 slab, are undoubtedly an improvement, but it is questionable whether 
 this method will prove to be entirely sufficient. 
 
 The subgrade should not be crowned, but peaked, as indicated 
 in the illustration. On this a sand covering about 2 or 3 in. in 
 thickness at the center can be well rolled to a flat surface. This will 
 allow a free movement of the water between the bottom of the slab 
 and the top of the impervious subgrade and should afford adequate 
 protection against the troubles outlined in the foregoing. 
 
 Oiled Shoulders Resist Erosion 
 
 A mountain road in San Bernardino County, Calif., with a 
 maximum grade of 5% presented a serious problem in the protection 
 
 (TANQGNTS) 
 
 (ctmvtof 
 
 Oiled Road Shoulders, San Bernardino County, California 
 
 of high embankments from the wash of storm water running off 
 the paved surface. The problem would have been simple if funds 
 
10 The Engineer in Field and Office 
 
 had been available for concrete curbs and gutters. Instead, the 
 following plan, illustrated in the accompanying cross-sections, was 
 adopted: The shoulders for 2 ft. in width were raised from 6 to 8 
 in. by filling with the adjacent gravelly soil, and were rounded off 
 to easy curves. The shoulders were then given two coats of 75% 
 asphaltic oil, each coat being properly sanded. Cutouts for the water 
 were provided at safely placed points and at culverts. This method 
 of construction formed an earth curb, and the pavement acted as 
 the gutter. The oiled shoulders have a sufficiently hard surface 
 to resist erosion and also serve to protect the edge of the macadam 
 from breaking down under wheel traffic. There was a considerable 
 saving over standard practice, the cost being only about 2c. per 
 lin.ft. of shoulder. J. S. Bright, Jr., Engineer, San Bernardino 
 County Highway Commission, San Bernardino, Calif. 
 
 Curb with Integral Expansion Joints 
 
 BY E. E. KIRKPATRICK 
 City Engineer, Bartlesville, Okla. 
 
 Better quality of work, better and more positive expansion 
 joints, less risk in construction, better protection against drying, 
 elimination of the danger of mortar scaling, elimination of the dam- 
 age caused by removing templets and forms while the work is 
 green, and a better top facing owing to the fact that it is placed 
 
 immediately after the body concrete has been deposited, are the 
 advantages derived from the new specification for concrete curbs 
 recently adopted by Bartlesville, Oklahoma. The curb, of the di- 
 mensions shown in the illustration, is blocked off into sections not 
 exceeding 7 ft. in length by transverse expansion strips not less 
 than -fa in. nor more than T % in. in thickness. These strips, placed 
 before the concrete is deposited, are composed of asphalt-roofing 
 sheets, asphaltic felt or other elastic asphaltic material cut to the 
 form of the cross section of the curb. 
 
Highway Engineering 
 
 11 
 
 The concrete is spaded thoroughly, the expansion strips being 
 held in place by thin boards or metal strips that are raised as the 
 concreting progresses. The mortar top dressing is placed as soon 
 as the form is filled. Dressed lumber is used for forms, and the 
 concrete is mixed to such consistency that with proper spading a 
 perfect face is obtained. 
 
 Save Trouble by Using Well-Built Forms 
 
 As the engineer watches the ordinary contractor set his side 
 forms for concrete roadwork, he easily realizes that not enough 
 consideration is given to their construction and grade layout facts 
 
 _ 
 
 *"->.gxf' I &= 
 
 <~6>\ wood Form 
 notched crs 
 
 FI0.4 
 
 Stands Much Rough Handling 
 
 which later on are sure to cause much extra trouble and loss of 
 time. The forms should not of course be built to a degree of over- 
 nicety, but should be so constructed as to prevent their becoming 
 
12 The Engineer in Field and Office 
 
 easily bent, warped or worn out of shape. Another feature often- 
 times overlooked is the desirability of staggering the joints, thus 
 preventing an undulation forming across the road in case the 
 joints are out of grade. To obtain a method of easily supporting 
 side forms for grade, 2 x 2-in. wooden stakes are driven to the 
 proper elevation of the bottom of the form; and they, in conjunc- 
 tion with alignment stakes which are not shown, and together with 
 the method of staggering the joints, make a satisfactory arrange- 
 ment. Figs. 2 and 3 show details of wooden side-form construction, 
 Fig. 2 showing the angle iron extending 6 in. beyond the end to 
 insure that adjacent forms will be maintained at the same elevation. 
 Fig. 3 shows a modified design that prevents the angle iron from 
 becoming easily bent when the forms are roughly handled, while 
 Fig. 4 shows a side form made entirely of wood. 
 
 Drainage Where Highway Parallels Railroad 
 
 BY C. S. BENNETT 
 Highway Engineer, Greenup County, Kentucky 
 
 In constructing a section of a state-aid road in Greenup County, 
 Kentucky, the highway paralleled the railroad for a distance of 
 one-half mile. The railroad fill is 8 ft. higher than the road surface 
 
 gpS^Wpsp 
 
 WTwvmgi 
 
 '^TWvv.-t <-.* 
 
 
 VillllllllllllllHIIIIIIIIIIIIIIHIMIIMMllUMIIIIllllllllilinHllliliiiiiiiinnilMllliilHHIII'HIIIinilllfJIIIiilljilllllllllll/llllMII 
 
 \ Culver i Pipe \ 
 
 ^llillllilllilliiilllilllllliiniiiiNhiiNMnl'nilllliiiiniiiiliHIiluviiiii.iiiiiiiiiMiiiiiiiiiiiiiiijiiiiiiiiuaiiiiiniiiiiiiiiiiiMMiiiiniii) 
 
 Drop Inlet Takes Care of Drainage Where Railroad 
 Parallels Highway 
 
 for about half of this distance. As all culverts extended through 
 both fills, it was decided to adopt the inlet method used on paved 
 roads and streets. Excavations were made in the ditch line over 
 the existing pipe culverts, all of which were 48 in. in diameter 
 and of corrugated iron, and a section was sawed out of the top of 
 
Highway Engineering 
 
 13 
 
 the pipe. Short sections of 12-in. corrugated culvert pipe were 
 then placed on end, and fastened to the large pipe by means of an 
 easily made metal collar through which several bolts were run. The 
 top of the riser pipe was provided with a concrete apron 6 in. thick, 
 the width of the bottom of the ditch, and extending about 3 ft. 
 along the ditch. A few small reinforcing bars were inserted in 
 the green concrete, and formed an effective grating which excluded 
 foreign materials. 
 
 Unusual Road Drainage 
 
 Lincoln Highway, east from Wooster, Ohio, at this point dips 
 from a comparatively level stretch to a grade of some 6 to 8%. 
 Across the ridge where the road begins to dip is an intersecting road 
 at right angles. At this point there was a culvert pipe on both 
 
 Unusual Drainage, Lincoln Highway, Ohio 
 
 sides, while open ditches were provided for drainage of the side 
 hill and to carry considerable accumulated water from the more 
 level place above. 
 
14 
 
 The Engineer in Field and Office 
 
 To avoid scouring on the deep side ditches on the improved 
 road, about 300 ft. of 30-in. corrugated-iron culvert pipe extending 
 from the crest of the hill to a creek at the foot of the hill has been 
 installed. Apparently it is not intended to be covered. Drainage 
 water from the level stretch on the opposite side of the road passes 
 through a culvert pipe at the crest and then is conducted diagonally 
 across the roadbed into the large culvert pipe by a segmental cast- 
 iron culvert pipe. 
 
 Stone Header Prevents Failures in Paving 
 
 Baltimore, Md., has adopted a detail of pavement construction 
 to prevent failures at such points where a hard paving material 
 like granite block, brick or wood block adjoins a softer material 
 like asphalt. This detail is as follows : A well-jointed stone header, 
 12 in. or more in depth and 4 or 5 in. in width, is constructed across 
 
 ^.-Wearing Surface 
 
 ... vitrified Block 
 
 Sunken Stone Header Prevents Failures in Paving 
 
 the street parallel to and 14 in. below the finished surface. The 
 concrete base is placed on one side of the header for the block 
 pavement, and on the other side for the asphalt pavement. The 
 blocks are laid tight against the header, which in case of a 3i-in. 
 vitrified block gives a 2-in. bearing. When the asphalt is laid, the 
 binder course is brought flush with the header; and the topping or 
 wearing surface is laid over the header to the finished contour of 
 the street, thus leaving the header 14 in. below and entirely hidden 
 from view. 
 
 Road Surface Affects Tractive Effort 
 
 A series of tests has just been completed in California which 
 was planned to determine the tractive effort required to move 
 vehicles over various types of roads. Tests of a similar character 
 
Highway Engineering 
 
 15 
 
 which were previously made, notably by the U. S. Office of Public 
 Roads and Rural Engineering, afforded no data suited to California 
 conditions or which could be used as the starting point for the 
 further series of tests in tire wear and gasoline consumption which 
 is contemplated. 
 
 100- 
 
 o- 
 
 TEST NO. 50, CONCRETE 
 
 83lb. 
 
 TESTN0.46. OIL MACADAM REVERSE (DOWN GRADE) 
 
 Dynamometer Curves Vary Much 
 
 In planning the tests, it was decided to concentrate effort on 
 securing constant conditions for a short length of time during which 
 measurements could be made, rather than to make long runs and 
 average the results. This policy was considered the best where 
 experiments were to be made on the open highways and on several 
 types of roads. One vehicle was therefore equipped and moved at 
 the same speed over the various road surfaces to be compared. For 
 this service a standard farm wagon was selected, equipped with 
 steel axles of equal length and 38- and 46-in. wheels in front and 
 rear, respectively, all wheels having 4-in. tires. The gross load 
 was 3 tons, consisting of rice in sacks. The speed was kept very 
 close to 2.4 miles per hour, and tests were run on level grades or, 
 
16 The Engineer in Field and Office 
 
 where slight grades were unavoidable, test runs were made in 
 both directions and results averaged. At the time of the tests the 
 usual sunny summer weather obtained, with maximum temperature 
 of 105. 
 
 The tractive effort was measured by a small dynamometer 
 attached to the tongue of the wagon, which recorded the momentary 
 pull at all times during the test runs and the total pull for the 
 test period. The measurement of distance is accomplished by 
 unwinding a cord of definite length from a drum within the device. 
 In a 50-ft. run an error of 6 in. in cord length, due to stretching 
 or any other cause, would introduce an error of only 1% in the 
 result. 
 
 The record of tractive effort is made by the pencil actuated by 
 a lever attached to the strong spring compressed by the pull. The 
 integrating device operates on the planimeter principle, but as the 
 measuring wheel makes one revolution for each 4 in. and can be 
 read to one-thousandth of a revolution, the instrument is 10 to 20 
 times as sensitive as the ordinary planimeter. 
 
 RESULTS FAVOR UNSURFACED CONCRETE 
 
 As shown by the accompanying table and curves, the resistance 
 encountered on oiled surfaces was considerably more than on 
 
 TYPICAL, RESULTS FOB VARIOUS SURFACES 
 
 Tract. Resist. 
 
 Test No. Kind of Road Condition of Road Location Total Per Ton 
 
 29-30-31 Concrete 
 
 (unsurfaced) . . Smooth, excellent Near Davis 83.0 27.6 
 
 * 11-1 2 Concrete 
 
 (unsurfaced) . . Smooth, excellent Near Davis 90.0 30.0 
 
 26-27-28 Concrete (%-in. 
 surface as 
 phaltic oil and 
 
 screenings) ... Smooth, excellent Near Davis 147.6 49.2 
 
 13-14 Concrete ( % -in. 
 
 surface as- 
 phaltic oil and 
 
 screenings) ... Smooth, excellent Near Davis 155.0 51.6 
 
 9-10 Macadam 
 
 (water-bound). Smooth, excellent Near Davis 193.0 64.3 
 
 22-23 Topeka on con- 
 crete) Smooth, excellent Near Davis 205.5 68.5 
 
 Gravel Compact, good condition.. Near Davis 225.0 75.0 
 
 t45-48 Oil macadam ... Good, new Near Sacramento 234.5 78.2 
 
 J46 47 Oil macadam .. . Good, new Near Sacramento 244,0 81.3 
 
 33 Gravel Packed, in good condition. . Near Davis 247.0 82.3 
 
 18-19-20 Topeka on plank Good condition, soft, wagon 
 
 left marks On Causeway 
 
 near Davis . . 265.0 88.3 
 
 34 Earth road .... Firm, 1%-in. fine loose dust Near Davis 276.0 92.0 
 
 24-25 Topeka on plank Good condition, but soft. . . Near Davis 278.0 92.6 
 
 1-2-5 Earth road Dust % to 2 in Near Davis 298.0 99.3 
 
 3-4 Earth Mud, stiff, firm underneath. Near Davis 654.0 218.0 
 
 6-7 Gravel Loose, not packed Near Davis 789.0 263.0 
 
 * Graphic record indicates that the load was being accelerated when test was started, 
 t Drawn with motor truck at 2% miles per hour. J Drawn with motor truck at 5 
 miles per hour. 
 
 concrete. It was pointed out that this difference would be less at 
 
Highway Engineering 
 
 17 
 
 lower temperature, but the tests were made under normal conditions 
 in the central California valleys. 
 
 Curves for Tests Nos. 2, 3 and 7 
 
 The supervision of the tests has been in the hands of Prof. J. B. 
 Davidson, of the University of California, who is the inventor of 
 the dynamometer. 
 
 Side-Hill Fill Held by Trees 
 
 In the construction of one of the roads in the northern part 
 of New York State the side-hill fill has to be made over a wooded 
 area. The usual procedure in such cases is to cut off the timber, 
 leaving the ground clear before beginning to make the fill. In 
 this case it has been decided to leave the trees standing on the 
 supposition that by so doing the fill will be less apt to slip. The 
 only clearing of trees which will be allowed will be in the space 
 included between shoulder lines. 
 
18 
 
 The Engineer in Field and Office 
 
 Pavement Along Rails Should Be Lowered 
 BY E. W. WENDELL 
 
 Assistant Engineer, New York State Highway 
 Department, Albany 
 
 All pavements, within the line of possible 
 contact, should be laid below the plane of the 
 tread of a car wheel. Consider the case of a T- 
 rail such as is shown in the illustration though 
 it should be borne in mind that the above rule 
 holds for any other type of rail. The rail head is 
 2i in. wide, while the wheel tread is 3 in., meas- 
 ured from the gage line. Hence, even without 
 any wear in the tread, if the pavement is flush 
 with the rail top the tread will ride in contact 
 with the paving surface for the width of the 
 overhang. But the rail head wears, and not in- 
 frequently the tread grooves, so that the over- 
 hang is below the head on tangent track. While 
 perhaps the railway company should be pro- 
 hibited from using such equipment, it must be 
 recognized that such cars are owned and oper- 
 ated; and as long as an adverse condition exists, 
 engineers should meet it with proper design. 
 
 The speed of cars being generally regulated 
 by law to a certain safe maximum, there is no 
 necessity for elevating the outer rail on curves 
 to an amount that will distort the cross-section 
 of the street and spoil the section. The illus- 
 tration shows a 2-in. elevation, but this is more 
 than will be found in practice except in very 
 unusual cases. This section shows clearly the 
 details and dimensions used to overcome the 
 destructive effect of the overhanging tread, but 
 even on tangents at least a Hn. difference in 
 grade should be maintained between the rail head 
 and the pavement surface directly adjacent to it. 
 On curves the amount of superelevation must 
 first be decided upon, as from this is determined 
 the difference in elevation between the rail head 
 and the pavement surface on the inside of the 
 curve. 
 
Building Construction 19 
 
 The following are good rules to follow in determining these 
 points: (1) Place the outside rail (D in the section) at the eleva- 
 tion it would have were the track on a tangent; (2) in the case 
 of double tracks, give B the same elevation as D, if there is not 
 much longitudinal grade at the curve. This plan leaves the half of 
 the street on the outside of the curve with its normal crown, 
 and gives the other half a proper slope toward the gutter. If 
 there is much grade, an inlet may be located before the curve 
 is reached, to catch the gutter drainage, so that D can be placed 
 even with, if not below, the gutter grade; and B will be at the 
 elevation of C, with A below B the amount of the outer eleva- 
 tion. This method results in track drainage for the side of the 
 street at the outside of the curve and thereby eliminates the gutter 
 as a factor in the drainage. 
 
 Interesting Lights on Building Construction- 
 Theory, Design and Methods 
 
 A Standard Notation for Beam Flexure 
 
 The engineer should be as familiar with the application of the 
 formula for beam flexure as with the use of the multiplication table. 
 Because this formula is one of the most important in the whole 
 subject of stresses, a standard system of notation is desirable. 
 
 Sixty years ago Rankine gave in his "Applied Mechanics" the 
 fundamental equation, M = pl/y. Later writers have departed 
 from the notation of Rankine. A few present-day notations will be 
 quoted. 
 
 TEXTBOOKS STEEL-MILL, HANDBOOKS 
 
 Church M=^ Bethlehem... . m = - = fS 
 
 n 
 
 Heller M = - Cambria M = gj- = pS 
 
 X-i 
 
 Kent M = - Carnegie . . M = - = fg 
 
 n 
 
 Ketchum M= ^ Jones & Laughlin Mr = - = fS 
 
 Lanza M = ^ Lackawanna. . . . M = J 1 = PS 
 
 Ci 
 
 Merriman M = - f 
 
 c 
 
 Trautwine M = 
 
 It is true that variance in notation causes little trouble to engi- 
 neers making constant use of the equations, but to those who use 
 
20 The Engineer in Field and Office 
 
 them only occasionally it is a cause of annoyance. The writer 
 suggests the following as a standard notation: 
 
 A STANDARD NOTATION FOR BEAM FLEXURE 
 
 b = Width of beam, in inches 
 
 d = Depth of beam, in inches 
 
 Section = Section cut by plane perpendicular to longitudinal axis of beam 
 
 A = Area of section, in square inches 
 
 c = Distance from the neutral axis to the extreme fiber of section, in 
 
 inches 
 I = Moment of inertia of section about neutral axis, in inches to the 
 
 fourth power 
 Iv = Moment of inertia of section about axis parallel to neutral axis, in 
 
 inches to the fourth power 
 
 v Distance between these axes, in inches 
 
 r = Radius of gyration about neutral axis, in inches 
 
 L = Length of span, in feet 
 
 = Length of span, in inches 
 
 W = Total load uniform'y distributed, in pounds 
 
 w = Uniform load per foot of length, in pounds 
 
 = Load concentrated at any point, in pounds 
 M = Total bending moment at any section, in inch-pounds 
 
 = Stress, in extreme fiber of section in pounds per square inch 
 
 = Section modulus, in inches to the third power 
 
 E = Modulus of elasticity, in pounds per square inch (steel = 29,000,000) 
 
 D = Maximum deflection, in inches 
 
 ^I X | = Axes of coordinates 
 
 x, y = Distances of any point from axes of coordinates, in inches 
 
 General formulas : Iv = I + Av 2 ; I = Ar 2 ; S = - ; M fS = - 
 
 The letter n is universally used for the elasticity ratio between 
 steel and concrete, or E 8 -r- E c For this reason the letter c is used 
 in the above notation for the distance from the neutral axis to the 
 extreme fiber of section. 
 
 Stitch-Riveting of Struts 
 
 In a built-up member, fastenings between the parts are required 
 only at points at which these parts tend to move relatively to each 
 other. The usual practice in designing compression members, how- 
 ever, is to fasten the elements together in such manner as to guard 
 against any increase in the slenderness ratio in any element of the 
 column. Is this safe enough? 
 
 Suppose we have a strut made of two 6 x 3i x i-in. angles spaced 
 i in. apart, of length 96 in. Assuming the two angles to act to- 
 gether, r = 1.45 in., and l/r = 66.2. The minimum r for this angle 
 (Fig. 1) is 0.67 in.; hence, if we put the pin rivets at the center 
 of length, we have a slenderness ratio of 48 -=- 0.76, or 63.1, which 
 is slightly less than that of the main column. 
 
 In Fig. 2 is given an elevation of the column looking at the 
 face of the outstanding legs. Here is shown by means of dotted 
 lines the deflection that the column would probably take if given 
 a load aproaching its maximum capacity. There would be no 
 tendency at the middle section for one angle to move axially rela- 
 
Building Construction 
 
 21 
 
 lively to the other. The column would act, as far as the deflection 
 illustrated in Fig. 2 is concerned, as a column of length equal to 
 twice the distance between pin rivets. In this case r = 0.97 (see 
 Fig. 1). Multiplying 0.97 by 66.2, we have 64.2 as twice the allow- 
 able spacing of pin rivets. This calls for connections at each 
 third-point of the length. 
 
 \! 
 
 At 
 
 4 M 
 
 / 
 
 
 ,5 
 
 FIG. 1 
 
 " 
 
 PIG. 2 
 
 With a middle rivet only, the slenderness ratio for parallel axes 
 is 96 -^ 0.97, or 99. By the A.R.E.A. formula the allowable stress 
 for this ratio is 9070 Ib. per sq.in., while the allowable stress for 
 the entire column section, slenderness ratio 66.2, is 11,370 Ib. per 
 sq.in. Under the latter load the angles considered as independent 
 elements would be loaded 25.3% over their allowable stress. 
 
 Method of Erecting a Large Steel Dome 
 
 The 92-ft. dome of the Wealthy St. Baptist Church, Grand 
 Rapids, Mich., has a steel frame formed by eight main arch mem- 
 bers 35 ft. in span, with 19-ft. rise, framing into an octagonal 
 
22 
 
 The Engineer in Field and Office 
 
 crown diaphragm, 22 ft. wide across the points. The arches are 
 tied together at the heel by four trusses and four sets of angle ties. 
 
 The arches are 2 ft. deep at the top and 5 ft. at the outer ex- 
 tremity. Three lines of beams parallel to the base ties carry the 
 wooden ceiling and roof joists. The lateral bracing consists of a 
 system of rods together with a line of struts in the center of each 
 bay at right angles to the roof beams. A steel monitor frame 8 ft. 
 high surmounts the structure. 
 
 The erection procedure was as follows : A derrick of the required 
 height was raised, and the eight sides of the diaphragm were 
 riveted up around its base. With two sets of blocks, the ring was 
 raised to the final elevation, 45 ft. above the floor, and light timber 
 falsework placed underneath. The arches were raised with a gin 
 pole, bolted in place, and the base ties erected. The roof beams, 
 struts and rods were then placed. 
 
 Graphic Solution for Fink Roof Truss 
 
 A simple general solution for the graphical analysis of the 
 Fink type of roof truss can be made without resorting to the usual 
 expedient of substituting auxiliary members or using partly ana- 
 
 stress Diagram 
 Modified Fink Truss Analyzed Graphically 
 
 lytical methods. For example, consider the modified Fink truss 
 shown in the diagram. The only load affecting the truss members 
 LM and LK is CD, and hence these stresses can be readily found 
 graphically. 
 
Building Construction 
 
 23 
 
 Select any convenient point M' on the line drawn through d in 
 the force diagram parallel to the rafter of the truss. Draw M'U 
 parallel to ML, giving L' on the line through c. Draw UK' parallel 
 to LK, and WK' parallel to MN, as shown. The triangle L'WK' 
 thus formed gives the true stresses in ML and LK, and also the true 
 relative position of the point K' with respect to the parallel lines 
 through c and d. 
 
 The true position of K', however, must be on a line through h 
 parallel to HK, and therefore lies at k in the stress diagram found 
 by K'k drawn parallel to the rafter. With k located, the remaining 
 stresses are found as usual. The method can be applied to any 
 loading and to unsymmetrical Fink trusses. 
 
 Design of Concrete Retaining Walls 
 
 Diagrams for the designing of retaining walls are simpler and 
 more convenient than formulas. For the purpose of illustration 
 
 "TYPICAL SECTION HOR.PRESDIAGRAM 
 
 I 
 
 08/0 
 Values of Various -Functions. 
 
 Fig. 1. Dimensions and Quantities Walls Without Surcharge 
 
 two cases will be considered (1) that of a gravity wall without 
 surcharge, and (2) that of a gravity wall with railroad surcharge 
 
24 
 
 The Engineer in Field and Office 
 
 of Cooper's E-55 loading, with center line of track 8 ft. 6 in. from 
 the face of the coping. 
 
 A gravity retaining wall of the type shown in Fig. 1, which is 
 safe against overturning, will also be safe against sliding and 
 crushing the masonry, and with a suitable toe may be built upon 
 any ordinary foundation. We may then assume a minimum factor 
 of safety against overturning and find the widths of the base for 
 various heights. Assuming that the slope of repose of the filling 
 
 TYPICAL SECTION HOR.PRESJ)IASRAMS 
 
 Values of 'Various Functions 
 
 Fig. 2. Dimensions and Quantities Walls with Surcharge 
 
 is li to 1, the horizontal pressure on a vertical plane is, according 
 to Rankine, 0.286 of the vertical pressure. Earth has been taken 
 at 100 Ib. per cu.ft., and concrete at 150 Ib. per cubic foot. 
 
 The diagram, Fig. 1, gives the width of the base of the neatwork 
 for a factor of safety against overturning of exactly 2. Using a 
 minimum footing projection of 6 in. at the toe and 1 ft. at the heel, 
 the entire wall always has a factor greater than 2. The maximum 
 compressive stress in the concrete is 90 Ib. per sq.in., and the wall 
 will be on the verge of sliding when the coefficient of friction is 
 about 0.3. 
 
 The dead-load for the case of a surcharge wall is considered the 
 same as in case 1. The live-load has been taken as 11,000 Ib. per 
 lin.ft. of track, distributed from the base of rail and end of tie 
 
Building Construction 
 
 25 
 
 as shown in Fig. 2, the limits of the distribution being the face 
 of the wall and a line 6 ft. 6 in. from the center line of the track 
 midway between tracks, assuming a second track 13 ft. from the 
 first. The ratio of horizontal to vertical live-load pressure has 
 been taken the same as for the dead-load. The portion of the 
 live-load pressure uniformly distributed over the width 6 has been 
 assumed as adding to the weight and stability of the neatwork, 
 while for the entire wall the width & + 1 nas been used. No dis- 
 tribution has been considered beyond the plane of the face of the 
 wall, no matter what the length of the toe might be. 
 
 The horizontal-pressure diagrams are shown in Fig. 2, and the 
 widths of the base of the neatwork for dead-load and live-load are 
 plotted on the diagram, as are also the values for dead-load only, 
 The factor of safety against overturning for the neatwork is ex- 
 actly 2. The maximum compression in the concrete is 103 Ib. per 
 sq.in., and the wall will be on the verge of sliding when the co- 
 efficient of friction is about 0.3, as before. The limiting values for 
 the height of wall have been selected so as to make the diagram 
 general for all heights likely to be encountered. It is not intended, 
 however, to indicate that gravity walls of the extreme heights 
 shown could be economically built. For estimating purposes, the 
 quantities for the higher walls would be on the safe side. 
 
 Forms Designed To Leave Storage Space 
 
 As the street had to be kept open for traffic, storage for 1250 
 yd. was provided in a building recently erected in Toronto, Ont., 
 
 E^lS* Floor 
 
 STORAGE 
 
 Wide Space Between Bents for Storage 
 
 by employing specially designed form supports. The use of bents 
 with a wide space between them was made possible by unusual story- 
 
26 The Engineer in Field and Office 
 
 height of the first floor 18 ft. 9 in. and the fact that there was 
 no basement. The bents were 11 ft. apart at the top and 17 ft. 
 apart at the bottom, this construction being carried over an area 
 six bays wide and three bays deep. The fourth bay, in front of 
 the aisles thus formed, served as a connecting passage, and bents 
 were built lengthwise of it for the full width of the six bays. Teams 
 would drive into any of the first five bays, dump and return to 
 the street by way of the connecting passage and the sixth bay, 
 which was used for return only. 
 
 Each storage space thus provided had a length of about 75 ft. 
 and a width of 17 ft., giving a storage capacity of 250 yd. Two 
 bays were reserved for sand, two for stone, and one for cement. 
 
 Gypsum Roof Slabs of 10-Ft. Span 
 
 A roof covering composed of gypsum T-beam slabs 10 ft. long, 
 having a clear span of 9 ft. 8 in., is a feature of a steel-frame 
 building 190 x 200 ft. recently erected at Racine, Wis. These long 
 slabs, designed as the outcome of numerous tests made at the 
 University of Illinois, are of T-section, 15 in. wide and 8 in. deep, 
 with a thickness of H in. for the top, or flange, and 2i in. for the 
 rib. The ends are closed by diaphragms 15 in. wide and 2 in. thick. 
 Each beam has two -in. rods in the bottom of the rib, one of these 
 being bent up at the ends as a shear rod and looped so as to increase 
 the value of the bond stress. In the top flange is embedded a steel- 
 wire mat of No. 14 gage and 4-in. mesh. The weight is 16 to 17 
 Ib. per sq.ft. The joints are plastered on the outer surface. 
 
 These beams were made at the site, in wood forms, at the rate of 
 about 300 sq.ft. per hr. They only required 15 min. to set, from 
 the time the mold was poured until the forms were knocked down, 
 and were erected in place and walked upon within three hours after 
 being poured. They were designed to carry a uniformly distributed 
 live-load of 50 Ib. per sq.ft. with a safety factor of 4. Tests of five 
 sample beams 24 hr. old were made with loads of 2200 and 2400 Ib., 
 or 200 to 218 Ib. per sq.ft., with respective deflections of 0.034 and 
 0.070 in. The total loads were then increased to 3500 Ib., causing 
 slight horizontal shear cracks to appear, but without other signs 
 of failure. 
 
 In the roof construction these slabs, or beams, are carried by 
 light steel trusses for the saw-tooth portions and by steel purlins, 
 etc., for the flat portions, all of the supporting steel being spaced 
 10 ft. c. to c. In general the flat roof portion has a pitch of 1J in 
 12, while the saw-tooth construction pitches about 7 in 12. When 
 
Building Construction 
 
 21 
 
 a flat ceiling effect is desired, instead of the ribbed, or beam, ceiling 
 formed by these T-beams, the slabs may be of H-section, with the 
 top and bottom flanges of equal width. These weigh from 22 to 24 
 Ib. per sq.ft. for the live-load noted above. In such a roof now being 
 erected the beams weigh 22 Ib. per sq.ft. 
 
 Crane Runway Columns Carry Roof 
 
 A yard crane with supports designed to carry a roof over the 
 yard is an interesting feature of the new foundry plant for the 
 James A. Brady Co., at Chicago. The material yard is between 
 two buildings and is served by a 5-ton electric traveling crane. 
 
 tf 
 
 ~lLaw.i 
 
 rtsnj 
 
 .........^ 
 
 **4RnkiM''ie ?'-(,* ^"Cross Bracing 
 
 i.-*6v.-y*-v.- vi T*t5CW^V4^c & r^i ^% 
 
 fiSf^r^ 
 T/iis Runway for a Yard Crane Is Designed To Carry a Roof 
 
 Elevation of 
 Cross Bracing 
 
 The crane runway consists of 20-in. I-beams carried by brackets 
 upon columns about 42 ft. high. The runway is 180 ft. long, with 
 columns and trusses spaced 20 ft. c. to c. The columns are of H- 
 section, with a 10-in. web plate and four angles 5 x 3 in. Longi- 
 tudinal bracing is provided by a double line of 6-in. channels, form- 
 
28 
 
 The Engineer in Field and Office 
 
 ing an inverted T-section, between the columns, at a height of 15 ft. 
 above the ground. Horizontal and vertical diagonal bracing is 
 provided in three of the bays. 
 
 Temporary Stringers Carry Elevated Tracks 
 
 An opening 4 ft. wide in the structure of the Metropolitan 
 Elevated Ry., Chicago, was necessitated by changes in the bents 
 and spans where the line crosses the new Union Station. One new 
 bent was 4 ft. from the old one, and the adjacent girder span had 
 
 /Pt:to"x\ 
 
 i 
 
 NEYfBEKT 
 
 ^6- >|<~/0^ 
 
 NEWPAHELSPUCED TO 
 GIRDER* 
 
 Stringers Carrying Track Rails Across Gap in Elevated 
 Railway During Alterations 
 
 to be lengthened by splicing on an additional panel. Traffic could 
 not be interrupted; and while the work was being done, each rail 
 was carried across the gap in a stringer of trough section, the ends 
 of the stringer resting on the track ties at each side of the opening, 
 as shown in the accompanying drawing. 
 
 Tar Paper Deadens Noise of Trucks 
 
 To deaden the noise from passing trucks rumbling over a con- 
 crete floor, a factory in Norwich, Conn., has successfully used a 
 heavy tar paper pasted to the floor by paint. The method of appli- 
 cation is as follows: The floor is first given one coating of a gray 
 cement paint. On the following day, when the paint is thoroughly 
 dry, a second coat is applied. At the same time one side of a five- 
 
Building Construction 29 
 
 ply tar paper is painted; and when both paper and floor are still 
 wet, the paper is carefully laid wet side down on the floor and 
 rolled with either a roller or wide-tired truck until all signs of 
 air pockets beneath the paper disappear. The surface seems to 
 improve with age and very effectively reduces noise at a low cost. 
 
 Excess Volume of Flared Column Heads 
 
 In computing the volume of the capital or flare in a column for 
 girderless concrete floor construction, a simple method is to deter- 
 mine the volume of the flare outside of the column shaft, which is 
 itself figured as running from the top of one floor slab to the 
 bottom of the next slab above. Formulas for this additional volume 
 have been deduced by Edgar H. Mosher, of Washington. 
 
 Where V = volume of concrete to be added to the volume of a 
 straight column figured to the bottom of the slab; D, diameter of 
 flare or top of capital, and d, diameter of column, the formulas are 
 as follows: 
 For square columns, 
 
 T/ V^ **/ v^ 
 6 
 
 For round columns, 
 
 _ (D- dY(D 
 7.63 
 
 For octagonal columns, 
 
 7.23 
 
 These formulas are deduced from the truncated cone formula, 
 assuming 45 to be the slope of the flare. 
 
 Special Forms For Light Floor System 
 
 The designers claim a considerable saving in weight and hence 
 in cost over any other fireproof floor of equal strength for a floor 
 consisting of rows of small concrete beams or joists of T-shape 
 poured monolithically with their supporting beams or girders 
 between forms made up of spacing members or boxes of wood and 
 cores of bent sheet metal. The accompanying perspective shows the 
 general layout of the system, which may be used either on steel- 
 frame or on reinforced-concrete buildings. 
 
 In building the floor, a line of struts is placed in each lower 
 T-beam and capped with plank that serve as beam bottoms. On 
 
30 
 
 The Engineer in Field and Office 
 
 these plank as joists is then laid expanded or ribbed metal that 
 forms a ceiling base. Then metal forms bent to the shape of one 
 side of the T-beam are placed over each plank and held in position 
 by properly cut brace boards between beams and by stiffener planks 
 along the top. In the T-form thus made, the proper reinforcing is 
 placed and the concrete poured to make the T-beam. 
 
 Perspective of Layout of System 
 
 When these beams have set, the bracing boards are knocked out 
 and the beam metal forms released to be taken upward and used on 
 the next floor above. The beams are then overlaid with another 
 sheet of expanded metal, and the usual cinder concrete floor is 
 placed. For the upper (floor) layer a fireproof board could be used 
 in place of expanded metal. 
 
Building Construction 
 
 31 
 
 Concrete Cantilever Beams 
 
 Cantilever beams of reinforced concrete, designed to support an 
 outside entranceway leading from a bridge over the Fox River, and 
 flat-slab floors without column capitals, to facilitate the placing of 
 partitions, are two principal features in a 
 recently completed eight-story hotel at Aurora, 
 111. Above the cantilever entranceway for 
 three panels of its length the mezzanine floor 
 was also extended over the river on columns 
 supported by the cantilever beams, the heaviest 
 of which is here illustrated in detail. 
 
 The building is 70 x 100 ft. in plan, with its 
 main entrance on the south side and with a 
 second entrance at the northwest corner, where 
 ! the hotel adjoins the new bridge. This out- 
 
 > side entrance, which is indicated by the photo- 
 . graphs, cantilevers 10 ft. over the river, and 
 
 > results in saving space within the building 
 1 lines to such an extent that one more store 
 
 > is now available which would have been elim- 
 ? inated if this scheme had not been adopted. 
 
 In order to facilitate the locating and rear- 
 
 > ranging of partitions, flat-slab floors supported 
 ^ on square columns designed to eliminate the 
 I column capitals usually used were adopted. 
 1 The first-floor slab is 7 in. thick; the slabs 
 5 used on the upper floors are 6 in. thick. No 
 
 beams were required except the cantilevers 
 already described and beams for window lin- 
 tels and to frame around elevator and stair 
 openings. The design of the slabs proved to 
 be economical, four-way reinforcement of i-in. 
 rods being used. 
 
 The forms for the cantilever beams were 
 also constructed as a cantilever timber frame- 
 work, owing to the fact that the river bottom 
 beneath the outer ends of these cantilevers consists of boulders, dirt 
 and rubbish, making it impossible to drive piling on the shore. 
 
 
32 The Engineer in Field and Office 
 
 Window-Frame Clamp Saves Time and Room 
 
 When setting window frames in stone or terra cotta faced build- 
 ings, considerable time can be saved, as well as avoiding the 
 obstruction of floor space with long braces, by using the clamp 
 shown in the photograph. The long piece is a 2 x 4 to each end of 
 which is nailed at right angles a piece of board about 6 in. long. 
 Five nails are used in each end. The distance between the inside 
 edges of these boards is 1 in. greater than the distance between the 
 outer face of the jamb and the face of the brick backing. 
 
 The window frame is set up when the first jamb stones have 
 been placed, after which one of the braces is placed at each side. 
 
 Clamp Can Be Quickly Adjusted 
 
 The braces may be tightened with wedges, or by driving down one 
 side until the brace sets tight. They will hold the window frame 
 securely in place until the brick work is finished. 
 
 Anchor High Form to Face of Stone Retaining Wall 
 
 Anchor bolts were used as shown in the sketch to secure the 
 form for facing with concrete an old retaining wall of dry masonry 
 which supports a section of a railroad line that runs along the face 
 of a cliff about 100 ft. high. The wall extends down to a ledge about 
 
building Construction 
 
 33 
 
 50 ft. below the track. This ledge was about 10 ft. wide outside 
 the old stone wall, and the working space was still further reduced 
 by the thickness of the new wall, which was 4 ft. at the bottom and 
 18 in. at the top. The anchor bolts were of i-in. round rods, one 
 
 High Form on Cliff Face Anchored to Old Wall 
 
 end of each of which was split for about 2 in. to receive a wedge. 
 Holes 5 in. deep were drilled into the stone of the old wall, into 
 which the split ends of the rods, with small wedges inserted, were 
 driven. 
 
 As it was impossible to remove the bolts after the forms were 
 stripped, they were nicked with a hacksaw about 1 in. inside the 
 face of the form. When the forms were taken off, a few sharp blows 
 with a hammer knocked off the ends of the bolts inside the surface, 
 and the holes were plastered up. 
 
 Some Capital Things in Foundation Work 
 
 Use Pier Form as Inside Cofferdam 
 
 The pier-shaft form was set under water and did double 
 duty as inside cofferdam and concrete form in constructing the 
 shaft of the pier for the Division St. bridge in Spokane. The 
 cofferdam had been sealed under water, and two layers of bracing, 
 which had been required during the driving of the sheeting and 
 the placing of the seal, were then removed. This work was done 
 by a diver, taking out the crossbraces but leaving the tie-rods in 
 place. The form for the pier shaft, which was built of 2 x 8-in. 
 
34 The Engineer in Field and Office 
 
 tongue and groove sheeting, placed vertically, was stood up in 
 the cofferdam, brought to line and well braced inside with the 
 help of the diver. The cost of this form exceeded by a surprisingly 
 small amount that of similar work done in the open. 
 
 The extra width of the cofferdam and the batter of the pier 
 left a space 28 in. wide at the top and 16 in. wide at the bottom 
 between the outside of the form and the piles. Around this 
 space, about a foot of concrete was deposited under water, sealing 
 any leaks between the concrete and the bottom of the form. 
 This space was then carefully puddled with a mixture of gravel, 
 clay and manure, gravel being used to save the clay, which was 
 expensive. This formed a puddle-wall cofferdam for practically the 
 cost of a single line of sheeting, plus the cost of placing the 
 puddle material. Having tongue and groove walls on both sides, 
 the dam proved very tight. The method also saved considerable 
 time, the initial time for constructing the cofferdam being much 
 less than if it had been made with two rows of sheeting, and the 
 form and puddle work being carried out while the concrete seal 
 was setting, which time would have been lost. 
 
 A pump was put inside the form, the space unwatered and the 
 seal concrete carefully cleaned. The bracing inside the form was 
 taken out as the pier concrete came up. 
 
 Cofferdam on Uneven Rock Bottom 
 
 A cofferdam of Wakefield sheet piles, which was framed and 
 put in place as a skeleton before setting most of the piles, was 
 used successfully on the practically bare and very irregular rock 
 bottom at the site of one of the piers for the new Division Street 
 bridge in Spokane. 
 
 This bridge was a structure 70 ft. wide and about 600 ft. long, 
 consisting of three concrete arch spans with concrete viaduct 
 approaches. The pier between the second and third arch spans 
 was located in water which was 23 ft. deep at the lowest point, 
 at low-river stage. Being only a short distance above the falls, 
 there was a strong current at the bridge site. Soundings showed 
 that the site of the pier was crossed diagonally by a vertical 
 ledge, the bare rock at the downstream end of the pier being about 
 15 ft. below the water, while the rock at the upstream end, where 
 the depth was greatest, was covered with 3 or 4 ft. of sand and 
 fine gravel. It was planned to construct the pier on a concrete 
 seal placed on the rock under water, and it was necessary to use 
 a cofferdam because the irregular bottom made a crib out of the 
 question. 
 
Foundations 
 
 35 
 
 The cofferdam, the skeleton of which was built in the water, 
 towed to place and set before the insertion and driving of most 
 of the piles, was made 2 ft. wider and 3 ft. longer than the base 
 of the pier. Three layers of outside and inside waling, between 
 which the sheeting fitted, were framed and spaced at the proper 
 
 Frame for Sheet-Pile Cofferdam Supported by Driving 
 Down Slotted Piles 
 
 distance apart by bolting them to sheet piles placed at each cross- 
 brace, 16 ft. apart. In these piles, through which passed the long 
 bolts shown in the drawing, which held each layer of bracing 
 together, were cut H-in. by 4-ft. slots to permit driving them after 
 the dam was placed. So that they would not bind after the frame 
 had been drawn tight with the long bolts, 1-in. pipe sleeves, \ 
 
36 The Engineer in Field and Office 
 
 in. longer than the thickness of the pile, were placed around each 
 end of each long bolt in these slots. These sleeves, bearing against 
 plate washers inside the rangers, prevented their being clamped 
 tightly to the pile. The rectangular part of the frame was 12 x 73 
 ft. inside the sheeting, but the total inside length of the cofferdam 
 was 89 ft. on account of the two pointed nose sections. 
 
 In addition to the posts shown in the drawing between the 
 three tiers of bracing, the frame was X-braced for its entire 
 length in a vertical plane, and each layer was also X-braced with 
 2 x 6-in. planks. 
 
 Pile bents, braced above and below water, had been driven 
 out to the site of the pier for construction purposes and to serve 
 later as a support for the arch centering. Extending the entire 
 length of the pier and about 3 ft. from it, this falsework afforded 
 a good anchorage along one side of the dam. On this falsework 
 was a large stiff -leg derrick. ,The frame was moored and held 
 plumb by the derrick while being weighted with bags of sand 
 until it grounded on the downstream end. The upstream end 
 was weighted to float level with the lower end, after ' which the 
 slotted piles were driven, where the 4-ft. slots were long enough 
 to permit it, to a bearing. These piles were then bolted securely 
 to the frame, serving as legs to hold it in place while the remaining 
 Wakefield piles were set around it. Special piles were made where 
 necessary to secure tight closures. 
 
 When all the bays were filled, the piles were driven to rock with 
 a drop hammer, handled in swinging leads by the derrick, and 
 bolted to the frame, more weight being added to overcome the 
 increasing buoyancy. The piles were built up of 3 x 12-in. plank, 
 surfaced one side and one edge, and were dry when placed, so as 
 to swell tight. The only openings were now the slots, the irregulari- 
 ties on the bottom, and in some cases a hole as much as 3 or 4 
 ft. high where the slots did not permit driving a pile to bottom. 
 The large holes and slots were boarded up by a diver. 
 
 Concrete Bases for Old Bridge Piles 
 
 Replacing piling under wood bridges still in fairly good repair 
 as to caps, joists and flooring has been one of the big items of 
 expense in Sedgwick Co., Kan., for years past. The county is now 
 doing a great deal of permanent bridge and culvert construction, 
 but there are still many pile bridges over the larger streams which 
 will have to be maintained for a number of years to come. To 
 reduce this expense concrete bases have been placed under the piles 
 
Foundations 
 
 37 
 
 that have rotted dangerously at the ground line. Replacing a pile 
 always necessitates tearing up the deck of the bridge, removing 
 at least two or three joists and frequently the cap, and sometimes 
 requires falsework for the piledriver. Where it has been possible 
 to work on the ground and there was soil that would stand, a 
 repair gang has put in a concrete base, retaining the upper part of 
 the old pile. The chief difficulty has been to get down past the 
 root of the pile. This has been surmounted in most cases either 
 by pulling or digging out the lower part of the pile, or by moving 
 the top of the pile slightly. 
 
 -.own/e 
 
 ^Lagscrews 
 
 Base for Old Pile 
 
 A 7-in. post augur drills the holes to a depth of 5 to 8 ft. 
 Sometimes the holes are reamed out by a "jabbing digger" or a 
 pile spade, which operation allows a mushroom base to be formed. 
 Where shale or a very hard clay subsoil is encountered even 
 though only a few feet under the surface no attempt has been 
 made to penetrate it; nor have these holes been put down or bases 
 built where there is surface water. In a number of instances 
 where sand was struck below the surface, this sand was thoroughly 
 mixed with a sackful or less of cement, thus forming a base that 
 holds satisfactorily. This construction, however, is never attempted 
 except where the surface soil is firm and hard. 
 
 After filling the hole with concrete, a round sheet-metal form, 
 a little larger in diameter than the hole, is placed at the surface. 
 In the form three or four iron straps are placed, so that they will 
 
38 
 
 The Engineer in Field and Office 
 
 project 8 to 12 in. above the concrete. Each strap is drilled for 
 two lagscrews, and the straps are placed so that the pile slips 
 between them. 
 
 The top of the base is pressed down or cupped, using either a 
 wood form or a trowel. This device helps to keep the pile firmly 
 in place. The concrete sets for 48 hours before the pile, which is 
 secured with the lagscrews, is placed. Under favorable conditions 
 this method of repair is much cheaper than replacing old piles 
 with new, and it seems to be more lasting. 
 
 Cushion Blocks Reinforced by Vertical Rods 
 
 With a specially designed cast-steel hood fitted with a reinforced 
 wood plug rapid driving of steel sheet piles has been accomplished at 
 Dam No. 39, Ohio River. As many as fifty-four 25-ft. Lackawanna 
 piles have been driven with one driver in one 8-hour shift. The 
 
 Woodjkjshion 
 
 Secrion A- ''-> 
 Round Pins Transmit Blows and Save Cushion Block 
 
 hood is so constructed that either straight web, gusset, corner or T 
 piles can be fitted into the grooves in its under side. It is held to 
 the hammer by wire lines or by rods passing through If in. holes. 
 A circular hole in the head permits an oak block to be inserted as 
 a cushion to receive the direct blow of the hammer. This block, 11 
 in. in diameter, is bound with a 1 x 2-in. iron collar. This prevents 
 it from mashing up at the top. Holes are drilled in the block to 
 receive l-in. round iron pins which transmit the blow from hammer 
 to pile follower. 
 
Foundations 
 
 Spreading Piles Pulled Back By Turnbuckles 
 
 The column footings for the three-track elevated railway along 
 Stillwell Ave., Brooklyn, N. Y., were constructed across a swamp in 
 which the mud varied in depth from 15 to 30 ft. The piers were 
 supported on spruce piles 30 in. on centers, which were driven to 
 refusal with a 2000-lb. drop hammer into the sand and gravel under- 
 lying the mud. 
 
 Fill made p "^ * 6 '' 
 
 torefain fl ft 2'/&Wire 
 
 Footings M$\ ; Cables _ _CinderFHI_ 
 
 Spreading Footings Restored by Turnbuckles 
 
 Over the greater part of this swamp there was an ash fill 6 or 
 8 ft. in depth, which had been in place some 6 years. This fill 
 served to give lateral stability to the footings. At one point, 
 however, near a creek, there was no fill on the original salt marsh. 
 Here it was brought home forcibly to the engineers that piles 
 driven in soft material, although able to support the load brought 
 upon them, have little lateral resistance, and that a structure sup- 
 ported on piles under such conditions is liable to injury if a 
 horizontal force is brought to act on them. 
 
 The piers at this point are 7 ft. 2 in. by 9 ft. 8 in. in plan, sup- 
 ported by 12 piles each ; they carry a load of 145 tons. The contractor 
 laid a standard-gage track on a cinder fill about 2 ft. deep between 
 the two lines of piers, and used a 50-ton locomotive and flat-cars 
 
40 The Engineer in Field and Office 
 
 to haul structural steel. The load of 35 tons per car axle which was 
 thus brought to bear on the underlying mud forced it out laterally 
 against the piers. It sprung the piles and spread the opposite piers 
 apart 2 in. in the bent in question. 
 
 In order to repair the damage, two I-in. wire cables with turn- 
 buckles were passed around the piers. By drawing these up, it 
 was possible to pull the piers back to correct position. An earth fill 
 was made around the footings to retain them in their proper position, 
 the cables being left in place as an additional precaution. 
 
 Freezing Ground Acts Like Hydraulic Jack 
 
 Some 16-ton concrete piers in a Middle-West city were heaved 
 this past winter by as much as 3 in. and subsequently settled back to 
 their original elevation. This most unusual and extreme condition 
 cannot be explained by ordinary frost action, but can be accounted 
 for by the piers becoming the pistons of hydraulic jacks in which 
 frost produced the moving pressure. 
 
 This occurred where a bridge was being built in the course of 
 track-elevation work. Some heaving also occurred at an adjacent 
 street. The abutments and piers at both streets were poured during 
 the summer and autumn of 1916. The bridge steel could not be 
 placed until the following season, hence the piers and abutments 
 carried no load other than their own dead weight. 
 
 Where the most heaving occurred, only the center and south rows 
 of piers were appreciably affected. The north row was fairly well 
 drained and much drier than those to the south where all conditions 
 were favorable to waterlogging. The bottom of the north side piers 
 was about 4i ft. below the ground surface, of the center piers 4 ft., 
 and of the south piers 3i ft. 
 
 The discovery was made in March, 1917, that the south row of 
 piers had heaved by amounts varying from 0.07 to 0.22 ft. The 
 center row showed heaving ranging from 0.01 to 0.09 ft. The north 
 row showed nothing in excess of i to i in., most of which could 
 have been in the original setting. 
 
 After this was discovered, levels were taken at intervals of 
 3 to 5 days. As the ground thawed the piers settled back into 
 position until the highest corner of any grillage was but 0.06 ft., 
 or |-in. above what it should be. A settlement of as much as 0.18 
 ft. or 2i in. is shown. 
 
 The usual explanation would be that the frost penetrated to a 
 level below the bottom of the piers and heaved them by direct action, 
 but this does not seem adequate for the following reasons: 
 
Foundations 
 
 41 
 
 (1) It is very doubtful if the frost penetrated as low as the 
 bottom of the piers. 
 
 (2) If the frost did penetrate to below the bottom of the piers 
 there could not have been more than from 6 in. to 1 ft. of frost 
 at the most. This thickness of frost could not possibly heave a pier 
 nearly 3 in. Water expands about ^ of its volume upon freezing. 
 The expansion of water-soaked soil would not be greatly in excess 
 of this if as much. That would mean but 0.1 ft. upheaval for a 
 whole foot of frost under the pier. 
 
 If the pier is considered analogous to the piston of a hydraulic 
 jack and the water or semi-fluid mud is forced under the pier by 
 the pressure from the freezing expanding strata nearer the surface, 
 the action can be understood. 
 
 Piers Were Plungers in a Big Natural Jack 
 
 Let AB represent the surface of the ground. Suppose the 
 ground to freeze to a depth d, such that the frozen layer becomes 
 rigid and unyielding. Let the frost then penetrate to an additional 
 depth e. The layer e expands in freezing. It exerts a pressure both 
 upward and downward. The frozen mass d is unyielding and if 
 the weight of the pier is less than the force required to break the 
 rigid layer, the water and semi-fluid clay will be forced upward 
 like a piston. Such an action would account for any amount of 
 heaving. 
 
 At the other location, where there is practically no depression, 
 only 3 or 4 piers out of a total of 42 were found to have been 
 raised. The heaving varied from i in. to li in., only one pier having 
 been heaved the latter amount. But at this street no pier bottom 
 was less than 5i ft. below the ground surface. It is certain that 
 frost did not penetrate to that depth. It is unfortunate that test 
 borings for depth of frost penetration were not made at both 
 streets in order that more exact information might be had on this 
 point. 
 
42 The Engineer in Field and Office 
 
 Locomotive Tows Caissons to Place 
 
 The caissons launched for the bridge at Moncton, N. B., were 
 quickly and easily towed to place by a locomotive at slack tide and 
 moored before the treacherous currents of the Petticodiac River 
 had an opportunity to carry them away. 
 
 When the first caisson was completed, it was lowered by jacks to 
 sliding ways of 12 x 12-in. timber 24 ft. long. Each of these ways 
 rested on one of the four main ways, which were spaced on 14-ft. 
 centers under the caisson, giving an overhang of 13 ft. at each end. 
 The main ways, which were braced and blocked continuously, had 
 a slope of about 1 to 9 and were run into the ground at the lower 
 end to prevent their sliding. The struts between the main ways 
 were weighted with rails to keep the ways from floating at high 
 water. The forward ends of the sliding ways were also weighted 
 with rails to sink them as the caisson floated, when they were pulled 
 clear by lead ropes attached to their rear ends. 
 
 The caisson was launched one hour before high tide, while the 
 current was still running in slowly. As expected, it reached the 
 end of the ways before floating, giving time to get a li-in. steel 
 towing line aboard before the tide rose sufficiently to carry it clear 
 of the ways. 
 
 This line ran through snatch blocks on scows moored at pier 3 
 and at the site of the caisson, and was led from there to a third 
 sheave in line with a siding on the opposite shore, where the line 
 was attached to a switch engine. As the caisson floated, the loco- 
 motive started slowly, pulling it over to the first scow at pier 3. 
 The shackle pins on the mooring lines of this scow were knocked out 
 and scow and caisson together hauled over to the second scow. The 
 latter, moored near the location of the pier, had on board the anchor 
 lines up and down stream. These were quickly transferred to the 
 caisson, which was then dropped downstream to approximate posi- 
 tion. The entire operation was completed before the outgoing tide 
 interfered. 
 
 Bearing Test on Confined Wet Sand 
 
 A concrete slab-and-girder mat, with the wet treacherous sand 
 underneath confined by a ring of interlocking steel sheet piling, 
 supports the new boiler house and coal-storage plant of the New 
 York Steam Co., at Burling Slip and Water St., in downtown New 
 York City. The load of the boiler room averages 2.6 tons per sq.ft. 
 of the entire foundation ; for the coal-plant mat the load is 5.4 tons. 
 Before the Building Department would permit such a foundation to 
 
Foundations 
 
 43 
 
 be laid, it had to be convinced by tests of the safety of the method. 
 The sketch shows how the loading test was made and gives the settle- 
 ment by curves. 
 
 The test arrangement is really a model of the foundation pro- 
 posed. A steel sheet-pile box was driven to a depth of 26 ft. below 
 curb and the material inside excavated to a depth of 15 ft. A 
 concrete slab 2 ft. thick was placed on the sand bottom below 
 
 Lead in Tons per Sq.ft. 
 
 Loading Test for Unusual Foundation 
 
 groundwater. The slab was loaded with pig iron to give a maximum 
 load of 6 tons per sq.ft., and readings were taken on the four 
 corners. The greatest settlement after 237 hours was 0.061 ft., 
 the average settlement for this period being 0.047 ft. The time 
 curve shows that there was no settlement between load applications. 
 
44 
 
 The Engineer in Field and Office 
 
 New Ideas in Designing and Building 
 Bridges and Dams 
 
 Clear Form of Notes for Bridge Stake-Out 
 
 The following form of note keeping for stake-outs of bridge 
 bents has been found simple, quickly made and of ready reference 
 
 "HIGH BRIDGE" 5take-ou+ 
 
 Mark. on rock near left stake = elev 
 
 B.M.*2 1095.49 1 127.82 *bot. cap 
 6.5. __416./!0954bFtqs. 
 H. I. * 1099.65 3/3241 '32'-05*Heioh< 
 r d - 4.44 \ 3 60 lt 
 
 rELFootinqs l095.4|-qdd7.'QO 10.60-10-07^ 
 
 4- 
 Offset stakes I4'-07^" 
 
 Bent @Sta280t9fl5 
 
 Mark, top of left stake=elev^ 
 
 J.PT.U/ 
 Instrument "Transit AJ Y ) Z7 "'7 
 
 B.M*4 1113.55 1127.64- bah cap. 
 B.S = 0.33 r 1 109.03 = F 
 
 ^rllU9.UJ = rtqs. 
 
 j 9JI6.6I 'iS'-OTl^igM 
 
 r add 7.00 =9.07= 9'-Ol" 
 
 "I ' 1113.86 
 
 levFtqs->H09.03 y add 7.00 -9.07- 9'-QJ 
 
 add 
 Offset stakes 
 
 Record Bridge Stake-Out Operations in This Manner 
 
 on the job. If the bridge is on a grade, it is necessary to have 
 available, preferably in the same notebook with the stake-out records, 
 the information indicated in the accompanying table. 
 
 DATA ON "HIGH BRIDGE" 
 
 Station 
 
 280 + 80.5 
 
 280 + 98.5 
 
 281 + 16.5 
 
 Bent No. 
 
 12 
 13 
 14 
 
 Grade (1%) 
 Floor Surface Bottom of Cap 
 
 1129.82 
 1129.64 
 1129.46 
 
 1127.82 
 1127.64 
 1127.46 
 
 With the above data and benchmark levels readily accessible, 
 the staking out of the bridge bents is undertaken, and the operations 
 so performed are recorded in the manner suggested by the illustra- 
 tion of a typical field notebook opening. 
 
Bridges and Dams 45 
 
 Temporary Hinges for Concrete Arches 
 
 The common assumption that, with an arch curve laid out to 
 conform to the dead-load equilibrium curve the dead-load produces 
 no bending moments in the arch, is materially in error. This error 
 arises from the arch shortening produced by the dead-load compres- 
 sive stresses and is similar to a fall in temperature; it results in a 
 reduction of the horizontal thrust, with a consequent divergence of 
 the true pressure line from the assumed arch axis. The pressure 
 line then passes above the axis at the crown and below the axis 
 at the springing, thereby increasing the compression in the outer 
 fibers at the crown and in the inner fibers at the springing. 
 
 The magnitude of the foregoing error depends upon the propor- 
 tions of the arch. It may be neglected in arches having a rise 
 greater than one-fourth of the span ; but in flatter arches it becomes 
 increasingly serious. From some designs that have been worked out, 
 in which the depth of rib was uniformly 3% of the span length, 
 it appears that the addition to the dead-load stresses on account of 
 rib-shortening may attain considerable magnitude, especially in the 
 flatter arches. 
 
 A method of avoiding these additional stresses is to provide 
 hinges at the crown and springing during the erection of the arch. 
 Temporary hinges were employed by the late George S. Morison in 
 the construction of masonry arches; they have also been used in a 
 number of European bridges. These hinges should be closed by 
 pouring concrete into the joints only after the full dead-load is on 
 the structure and the shortening and shrinkage changes have taken 
 place. By selecting the temperature for closing the hinges, the range 
 and effect of the subsequent variation may be minimized. 
 
 The above advantages of the three-hinged construction apply 
 mainly to the conditions during erection. For the finished structure, 
 a hingeless type is to be preferred on account of the greater rigidity 
 and the greater security against crown settlement. Temporary 
 hinges eliminate the shrinkage stresses without involving the 
 difficulty in the construction of bulkheads caused by interference 
 with the steel in the case of reinforced construction. 
 
 Circular Curve for Arch Design 
 
 In laying out an arch curve for the first trial design, a simple 
 circular curve is ordinarily satisfactory. With this curve drawn, 
 the weights of the arch segments and superimposed filling are figured 
 and the resulting equilibrium curve constructed. With this pressure 
 line as a new arch curve, the deadloads may be revised and a second 
 
46 The Engineer in Field and Office 
 
 equilibrium curve drawn ; as a rule, however, the first curve may be 
 retained without the revision of a second trial. 
 
 For ordinary concrete arches with earth-filling up to a level line, 
 the ideal arch curve will be found slightly higher at the haunches 
 than a simple circular curve. The following table gives the amount 
 of this deviation, as found from actual designs, for different rise- 
 ratios : 
 
 Deviation from Circular Curve 
 
 Ratio of Rise at Haunches, in Per Cent. 
 
 to Span of Rise 
 
 0.25 4.3 
 
 0.20 4.2 
 
 0.15 3.7 
 
 0.10 35 
 
 0.07 3.1 
 
 In the flatter arches, the deviation from a circular curve is barely 
 noticeable. 
 
 Theoretically, the ideal arch curve is the equilibrium curve for 
 the dead-load plus one-half of the live-load covering the full span. 
 This curve would be the exact mean of the two extreme curves 
 obtainable by placing the live-load alternately on the two halves 
 of the span. In practice, however, on account of the usual small 
 ratio of live- to dead-load, there is no material difference in using 
 the equilibrium curve for dead-load alone. 
 
 Approximate Methods for Arch Design 
 
 The elastic theory when applied to arches with fixed ends is not 
 only time-consuming, but is essentially a method of analysis and not 
 directly of design. Hence there is a real need for satisfactory 
 formulas or methods for determining approximately the crown 
 thickness and the proper form of the arch ring. It is necessary 
 in order to determine the stresses to assume the dimensions of the 
 arch rib. Experience must be the main guide in this primary 
 assumption, and the designer has two classes of aids: 
 
 1. Emperical formulas, which are crystallized expressions of past 
 experience ; 
 
 2. Approximate methods, by which crown thrusts and lines of 
 pressure may be determined. 
 
 Formulas of the first class are the modern representatives of 
 the experimental proportions which probably guided the ancient 
 arch builders. Methods of the second class are an outgrowth of 
 the line of pressure theories developed for voussoir arches, and 
 are an improvement over class 1, principally in that a greater range 
 of conditions can be considered, and that more particulars of the 
 form of the arch can be determined by their use. 
 
Bridges and Dams 47 
 
 Joseph P. Schwada has developed formulas for the thrust T and 
 the depth d at the crown in terms of a coefficient K representing 
 the ratio between the average crown stress and the maximum stress 
 in the arch. The following equation has been derived for the thrust, 
 based upon the assumptions used by Mr. Schwada, but using the 
 general formulas derived by C. Tourtay in 1902. In Mr. Schwada's 
 notation : 
 
 This equation gives slightly lower values than Mr. Schwada's 
 equation, all terms being identical except those in the parenthesis 
 containing R and d. The depth at crown is 
 
 T 
 
 d = 
 
 144/Jf 
 
 Mr. Schwada presents a valuable series of diagrams and tables 
 for the value of the coefficient K, and for the solution of his 
 equations. 
 
 The process of the design of an arch ring is then as follows : 
 
 1. Tabulate the general conditions which can be at once deter- 
 mined or assumed, and the known factors such as span, rise, 
 loads, etc. 
 
 2. Make a rough assumption of the crown and springing line 
 thickness (possibly using a formula of class 1). 
 
 3. Compute the value of thrust T, and if necessary correct the 
 assumed crown thickness. 
 
 4. Construct a line of pressure with horizontal thrust (pole 
 distance in the force polygon) equal to T. 
 
 5. Choose a value for K which will suit the type, the rise, and 
 the span of the arch, and compute the value of the crown thickness d. 
 
 6. Choose a curve for the arch axis which will fit the line of 
 pressure constructed as in 4. 
 
 7. Vary the thickness of the arch and place the reinforcement 
 in accordance with the thrusts shown in the force diagram, but 
 making proper allowance for the effects of moving loads and 
 temperature. 
 
 8. Analyze the arch thus determined by the elastic method. 
 
 It will be found that a very close approximation to the best 
 design is determined by the first seven steps, and only minor changes 
 may be expected from the full elastic analysis, while the labor is 
 far less than a preliminary analysis by the elastic method. 
 
48 
 
 The Engineer in Field and Office 
 
 Culvert Pipe Used as Basis for Floor System to Bridges 
 
 A reversion to an old system of highway bridge floor, with some 
 modern variations, is seen in the use of corrugated iron culvert 
 
 Underside of Colorado Bridge Floor Where Culvert Half 
 Rounds Are Used as Forms 
 
 pipe forming the basis for concrete arch floor spans. In the old 
 designs light gage corrugated steel in the new type half sections 
 
 Concrete Floor of Ohio Bridge To Be Placed on Culvert 
 Sections as Forms 
 
 of heavy-gage culvert iron is used, with additional reinforcement 
 of the concrete floor against expansion. 
 
Bridges and Dams 
 
 49 
 
 One view shows such a floor as installed on a through-truss 
 bridge in Hamilton County, Ohio. For this bridge the culvert forms 
 span between the bottom flanges of I-beam stringers which are 
 framed into floor-beams. The other view shows the under side of 
 the floor of a deck-girder bridge at Boulder, Colo. Here the main 
 girders, 41-ft. span, are of reinforced concrete and the floor, a 
 concrete slab reinforced against expansion with l-in. rounds on 
 10-in. centers in both directions, is poured on half-culvert sections 
 spanning steel 24-in. I-beams which are spaced 4 ft. apart and 
 placed parallel to the main girders and span between the abutments. 
 In this bridge the I-beam stringers are stiffened by cross-braces 
 of steel bars, as shown. 
 
 Bridge Erected With A-Frame 
 
 An example of the solution of a difficult erection problem through 
 taking advantage of the exceptional natural conditions is seen in 
 the methods adopted in the case of the Pool Point Bridge on the 
 Elkhorn extension for the Carolina, Clinchfield & Ohio Railway. This 
 bridge crosses a deep basin in which there is always from 50 to 
 
 Center Support Was Provided for Cantilever Erection 
 
 90 ft. of water. The stream is of torrential character, and above 
 the site of the bridge is a splash dam which at times discharges 
 large numbers of logs which would carry out any ordinary falsework. 
 These special conditions made it impracticable to use falsework 
 of the usual type. The character of the rocky side walls suggested 
 the use of an A-frame or arch type of center support and cantilever 
 erection from the north shore for the 270-ft. main truss span. This 
 design was therefore made of the riveted type, with provision for 
 compression in the lower chords and proper sections throughout 
 for cantilever erection beyond the center-panel point. The A-frame 
 legs were made of derrick booms. 
 
50 The Engineer in Field and Office 
 
 The main truss span of nine 30-ft. panels, 270 ft. long, flanked 
 on the north by a 50-ft. girder span and on the south by a 70-ft. 
 girder span is composed of two trusses spaced 19 ft. apart on centers. 
 The main span weighs 613 tons, and the order of procedure in 
 erection was as follows: 
 
 The end post and 50-ft. plate girder span having been erected 
 by the derrick car, the car could be advanced and the first panel 
 placed with a temporary wooden bent at panel point Lj. The car was 
 then advanced and the A-frame legs were placed on the north side 
 and held in position by guys. Following this, lines having been 
 passed to the other bank, the south legs of the A-frame were swung. 
 
 The shore ends of the A-frame had cast-steel bolsters supported 
 on concrete skewbacks and the tops were provided with cast-steel 
 shoes for supporting the truss. The A-frame being in place, the 
 remaining panels up to the center were erected, the splices being 
 located as shown on the diagram, and the center panel point blocked 
 up on top of the A-frame. From this point cantilever erection 
 proceeded regularly panel by panel until the shoe at the south end 
 had been placed. 
 
 The deflection of the cantilever end was about 8 in., and care 
 had been taken to block the center high enough to bring the south 
 end about a foot high, allowing for this deflection. Jacks were then 
 applied and this south end lifted until the span was free at the 
 center. The A-frame was removed and the span lowered to the 
 masonry. 
 
 Radial Bracing for Large Cofferdam 
 
 In constructing a steel sheet-pile cofferdam 46 ft. in diameter 
 for the Pennsylvania R.R. it seemed desirable to use a quantity of 
 8 x 16-in. 18-ft. timber, which was on hand, for bracing. As the 
 distance across the cofferdam was more than twice the length of 
 the timber, a wood pile was driven in the center of the cofferdam 
 before excavating; and a "hub" supported by this pile was 
 constructed. Excavation has been carried 18 ft. below water level, 
 and two sets of waling and struts have been placed in this manner. 
 The method has been very successful. 
 
 Forms Have Sliding Cantilevered Studding 
 
 Cantilevered vertical studding which does not have to be taken 
 down to set the next lift of forms is used to support the forms for 
 La Loutre dam, being built on the upper St. Maurice River. By the 
 use of such supports the interior spaces where concrete is being 
 
Bridges and Dams 51 
 
 deposited are kept clear of all tie rods. Two pieces of timber on 
 edge are held parallel and 1 in. apart, being double bolted through 
 a space block at the upper end. This arrangement gives a slot the 
 whole length of the support, so that it can be slid vertically upward 
 for another lift of concrete. In this respect the scheme differs from 
 previous forms of same type. 
 
 The holding bolts are tightened when the form and support are 
 in place for proper alignment. If there is any overhanging, the 
 heel or lower end of the support is blocked outward. Form framing 
 here is horizontal and lagging is vertical. 
 
 Holding bolts 1 in. in diameter are spaced at 2-ft. intervals. The 
 bolts are wrapped in a sleeve made of paper which has been dipped 
 in tar and dried. At the inner end is a 3 x 3 x T 5 F -in. plate. Very 
 little difficulty has been found in screwing the bolts out. Large 
 square washers at the end span both timbers of the support. 
 
 Automatic Flood Gates for 17-ft. Dam 
 
 The 17-ft. concrete dam for a hydro-electric plant on the Cedar 
 River at Nashua, Iowa, is equipped with a number of automatic flood 
 gates each 46 ft. long and holding back a maximum of 7 ft. of water. 
 The installation of the flood gate is worthy of comment, because 
 this particular type is new to this country. It was imported from 
 Switzerland and service has already proved its value. It is simply 
 a walking-beam with a gate hung at one end and a concrete 
 counterweight hung at the other. The gate is hinged at the bottom. 
 When the water rises above the required elevation, the gate turns 
 down, which in turn raises the counterweight. The higher the 
 water the farther it opens the gate. When the gate opens, the 
 leverage between the counterweight and fulcrum increases and that 
 between the gate hinges and fulcrum decreases, thereby overcoming 
 the increased weight of water at every stage of gate opening. 
 Gravity and constantly shifting leverage are its features. The gate 
 is of steel and was entirely fabricated and set before grouting in. 
 
 Creosoted plank was used for decking, well bolted on. Leaking 
 around the ends was prevented by a leather bearing on the concrete. 
 A leather bearing on a curved plate prevented leakage over the 
 hinge where the gate fastened to the rollway. The counterweight 
 was formed and poured in place, being shored up from the crest of 
 the dam. 
 
 Concrete Closing Slabs Slide to Place 
 
 On the construction of the dam at the new hydro-electric plant 
 at Hiram, Me., on the Saco River, water was allowed to flow through 
 
The Engineer in Field and Office 
 
 the dam during the main building period, three openings being left 
 in the lower part of the deck. Closure was then accomplished by 
 three reinforced concrete gates which were cast upon the deck of 
 the dam as shown and each held in position by a wire rope attached 
 
 /7& close Ga+e 
 saw Loo here 
 
 ^issyS?:\ 
 
 #'& 6ATE''* : \ $>> ; 6ATE ' 
 
 p^^iM^I^;- 
 
 &.4^fiM^*^*4*i'*A 
 
 S e c -t- i o n 
 
 Sec-Hon through Ga-f-es 
 
 Ups-t-ream Eleva-fion 
 
 Slabs Slid Down Deck of Dam on Greased Tarpaper 
 To Make Closure 
 
 to log anchored under the opposite wall of the dam by a second rope 
 and hook. Each closure gate was reinforced both ways with l-in. 
 square rods spaced 4 in. on centers and was provided with a U-bolt 
 by which the wire attachment was made. To prevent adhesion 
 between the closure slabs and the deck of the dam, two layers of 
 single-ply roofing paper, greased between layers, formed the base 
 upon which the concrete was poured. The closure gates were about 
 16 ft. high, 18 in. thick and 15 ft. wide, sliding downward between 
 guides composed of 4-in. tees flanked by 4-in. by i-in. plate on each 
 side. By sawing off the log above each gate on the top of the 
 dam the slab was released and slid into place seating against a 
 concrete recess at the bottom of the deck, as shown in the cross- 
 section. 
 
Bridges and Dams 
 
 Slipping Bridge Abutment Saved 
 
 A casual inspection of the 100-ft. steel highway bridge which 
 was built some time ago without engineering supervision showed 
 that the anchor bolts were bent and the shoes were pressed tightly 
 against them. There was no information available as to the exact 
 location of the abutment or as to the batter of the faces, but it was 
 very easily seen that one of the abutments had moved. An 
 investigation indicated that while one abutment rested on hardpan 
 or rock, the other which is about 18 ft. high above water level 
 and of unknown depth below probably rests on a fine sandy loam. 
 The stream channel shifting had eroded this deeply. 
 
 To prevent further erosion, two lines of piles were driven near 
 the toe of the slope and the whole slope covered with a heavy riprap 
 of stone. Holes were drilled through the abutment near the 
 juncture of the wings and face, and 14-in. rods, 34 ft. long, were 
 
 Abutment Retained by Concrete-Incased Rods Passing 
 Through Concrete Deadmen 
 
 placed in trenches running back along the roadway. These rods 
 were incased in concrete for their entire length and anchored to 
 concrete deadmen at the end. 
 
 To further strengthen the abutment, a narrow trench was dug 
 along its back and filled with concrete the extra width providing 
 
54 
 
 The Engineer in Field and Office 
 
 sufficient breadth to receive the bearing when it was replaced in its 
 proper position. 
 
 When the concrete at this point was hardened sufficiently, the 
 nuts were tightened on the tie-rods, a new anchor bolt hole drilled 
 and the bolt grouted in. To lift the bridge while widening the 
 seat beams, struts made of pine logs flattened on two sides were 
 attached at the first panel points, as is indicated in the line drawings. 
 A beam rested on top of these struts and passed under the top chord. 
 The bottom chords, stiffened by means of 4x6 timbers inserted 
 between the floor-beams, completed the provisions against reversed 
 stresses. 
 
 Arches Destroyed by War Replaced Quickly 
 
 The exigencies of battle in the north of France have required 
 the rapid and stable reconstruction of a number of masonry arch 
 bridges that had been more or less completely destroyed by the 
 German or by the Allied forces. These bridges are generally in 
 an area where timber and cut stone are scarce, and their 
 reconstruction must be done rapidly without the aid of the needed 
 quota of skilled artisans. To meet these conditions, concrete arches 
 placed without the use of falsework have been successfully 
 employed in a number of cases. 
 
 Method of toying Up Arch 
 
 Fig. 1. Restoring Arches in Destroyed Stone Bridges in Battle 
 Area of France 
 
 Cement can more readily be brought forward than any other 
 structural material, and sand and gravel are local products, so that 
 concrete, which can be made by unskilled labor, is doubly effective 
 for such work. A novel feature of the reconstruction is the use 
 of old iron and a minimum of timber for arch centers, which can 
 be readily erected, thus saving time and labor. 
 
Bridges and Dams 
 
 55 
 
 The first operation in the reconstruction of one bridge was to 
 build the light timber framework carrying the footway and erect 
 thereon the towers for a construction cableway. From this cableway 
 a series of centering ribs made up of old steel rails was placed. 
 These rails, which were found in the neighborhood, weighed 60 Ib. 
 to the yard. They were cold bent to the proper curve, in two 
 sections and spaced 20 in. c. to c. clear across the arch. At the 
 abutment they were bolted to a bedplate that was held by a hook 
 bolt driven into the masonry. These curved rails were used as the 
 basis of a thin concrete arch that in itself served as the center for 
 the main arch. This procedure was adopted rather than placing 
 the main arch immediately upon falsework hung from the steel 
 ribs themselves, because the rails were not sufficiently strong to 
 act as centers. 
 
 Cross-Section of Falsework Center 
 60- Ib. Rail 
 
 Bearing 
 Of Kail 
 
 . a+ 
 Abutment 
 
 Elevation of 
 
 Falsework Center 
 
 Fig. 2. Details of the Steel-Rail Arch Centering Used on 
 Meurthe River Bridge 
 
 The centering consisted merely of timber joists and a floor. 
 This concreting was done in two parts, a 1:2:4 concrete was 
 placed for its uniform thickness of 10 in. from abutment to 
 abutment, and for the full width. On this a concrete arch rib and 
 two abutment sections were first placed and the intermediate 
 sections last. The concreting of this shallow section could be 
 done in one morning. Ten days was allowed for this concrete to 
 set. Meanwhile the top of the rib was laid off in 19 voussoirs, and 
 a vertical dividing wall was erected across the arch at each voussoir 
 division line. This dividing wall was made of a wire mesh, large 
 
56 The Engineer in Field and Office 
 
 enough to hold the aggregate, fastened to f-in. and f-in. vertical 
 rods tied in at the bottom to hook bolts that had been left emerging 
 from the centering concrete. These frameworks having been 
 placed during the 10 days allowed for the setting of the centers, 
 concreting was carried on across the arch rib in the voussoirs so 
 laid out, placing them across the bridge so as to impose the least 
 eccentric loading on the centering arch. The progress of voussoir 
 deposition is shown. All this concreting for one 6-ft. arch could 
 be done in two 10-hour days. 
 
 After the main arch rib has achieved a sufficient set, the 
 centering arch can be removed, although this is not necessary. 
 Meanwhile, the superstructure of the arch can be erected in a 
 continuous process following the construction of the main arch 
 rib, and the roadway put into service in a minimum of time. 
 
 Top Forms in Arch Concreting 
 
 Top forms were considered necessary on the new Chesapeake & 
 Ohio Northwestern Ry. work at Sciotoville, Ohio. It has long been 
 usual in concrete bridgework to omit top forms near the crown of 
 the arch where the slope is very small, but of late it has become 
 rather common practice to omit these forms far down the arch rib 
 slope and to attempt to screed the top surface to line. Concrete 
 so placed is apt to pile up, causing an excess of arch-ring depth at 
 the bottom of the section poured and a thinning of the ring near 
 the crown. Therefore a top form for the haunch section of the 
 arch ring, which extends from the springing line to a crown section 
 placed in advance about 3 ft. on either side of the crown, was used 
 on this bridge. 
 
 A Small Bobtail Draw 
 
 In building a swingbridge across a neck of Lake Lucerne at 
 Stansstad, Switzerland, for 22 m. clear opening, the engineers for 
 the Canton Nidwalden adopted the bobtail swing type but detailed 
 it in such manner as to make substantially a single-leaf swing. The 
 short arm ends just beyond the turntable, so far as the bridge floor 
 is concerned. It extends out under the approach floor, however, 
 as counterweight for the long arm. The approach deck over this 
 counterweight has supports at one side only, the other side being 
 left clear to allow the counterweight to swing out. The result of 
 this arrangement is that rocking action due to live-load on the 
 short arm is nearly eliminated, making it possible to dispense with 
 wedging Or tight latching at the outer end of the long arm, as well 
 
Municipal Engineering 
 
 57 
 
 as with bearings under the short arm. The operating machinery 
 is thereby simplified, and the required power reduced, which (the 
 bridge being hand-operated) means that the time required for 
 opening and closing is reduced. The end of the long arm has one 
 lower and two upper track-wheel supports, and these enter between 
 tracks inclined slightly upward, as the bridge closes. There are 
 also two flat bearings, one under each girder, but they are adjusted 
 to be barely in contact when no live-load or wind is acting. The 
 turntable is center-bearing and has two side wheels and two at the 
 quarter-points nearest the channel. 
 
 Field Determination of Bridge Skew 
 
 In reconnoissance work for ordinary highway bridges no great 
 accuracy is required in determining the skew; even a variation of 
 5 being seldom important. A method of determining this skew in 
 the field is to take an ordinary 6-ft. rule, hinged about its 3-ft. 
 joint, place one arm in the line of the road and the other arm in 
 the line of the stream; the distance between the two ends is the 
 chord of the angle of skew of the bridge. The following is a table 
 by which the angle can be determined : 
 
 Radius equals 36 in. 
 
 Chord 
 
 18 in. 
 
 20 in. 
 
 22 in. 
 
 24 in. 
 
 26 in. 
 
 28 in. 
 
 30 in. 
 
 32 in. 
 
 34 in. 
 
 Angle 
 29 00 
 32 20 
 35 
 39 
 
 42' 
 45< 
 49 C 
 52 C 
 56' 
 
 40' 
 00' 
 20' 
 40' 
 20' 
 40' 
 20' 
 
 Chord 
 
 36 in. 
 
 38 in. 
 
 40 in. 
 
 42 in. 
 
 44 in. 
 
 46 in. 
 
 48 in. 
 
 50 in. 
 
 Angle 
 60 00' 
 63 40' 
 20' 
 20' 
 20' 
 20' 
 40' 
 
 67 
 71 
 75 
 
 79 
 83 
 
 88 00' 
 
 Intermediate angles can easily be interpolated. 
 
 Helps for Municipal and County Engineers 
 
 Tile Drains Under Curbs in Syracuse 
 
 The accompanying sketches show how the City of Syracuse 
 drains all pavement foundations. The curbing is set in a block 
 of concrete 18 in. wide and 12 in. deep. Under this block of concrete 
 is 18 in. of cobblestone filling, along the edge of which is laid a 3-in. 
 tile drain which empties into the sewer catch-basins. Wherever 
 there are street railway tracks a 5 x 16-in. Medina curb or header 
 is placed against the ends of the ties and a similar construction, 
 as shown in the right-hand sketch, is used. It is said that in the 
 
58 
 
 The Engineer in Field and Office 
 
 spring, when the frost is coming out of the ground, these drains 
 empty a continuous flow into the sewer catch-basins, and there is 
 
 MZDINA CURB 
 
 Fbrvemen-f- 
 
 3"Tile- 
 
 Standard Drainage Details for Concrete Curb (Left) and 
 Special Curb at Railroad Crossing (Right) 
 
 no question but that they save many pavement troubles. They are 
 used in all kinds of subsoil and beyond the price of the tile they 
 add practically nothing to the cost of the pavement. 
 
 Types of Drinking Fountains Tested 
 
 Tests of 77 drinking fountains of 15 different types showed 
 that due to improper design all were possible sources of infection 
 of the users. No less than 80% of the fountains and the water 
 from 11% of them contained streptococci, although none were 
 
 These Fifteen Types Showed 80% o/ the Fountains and 11% 
 oj the Water Samples Infected 
 
 found in the water supplied to the 18 buildings in which the 
 fountains were located. 
 
 The infection was due to contact between the lips of users and 
 the structure of the fountains, or to water falling back from lips 
 
Municipal Engineering 
 
 59 
 
 to fountains, owing to vertical discharge of the jet. To keep lips 
 away from the fountain structure and water from falling back on 
 it, and to prevent water from being retained in fountains with 
 
 Three Tests of This Protected Drinking Fountain Showed 
 No Streptococci Infection 
 
 cup- or ring-shaped depressions, the fountain shown herewith was 
 designed. Three bacterial tests showed no streptococci on either 
 the fountain or the water discharged from it. 
 
 When To Haul, When To Waste and Borrow 
 
 A simple formula by which to calculate the economical length 
 of haul beyond which it is preferable to waste and borrow may be 
 developed as follows: 
 
 Take two adjacent sections, one in cut, the other in fill, and 
 each containing the same volume of material V, measured in 
 excavation in both cases. Under this condition the material taken 
 from the cut will just make the fill, and therefore, provided the haul 
 from cut to fill is of a certain length, the total cost of grading the 
 two sections, with all the material from cut used in fill, will be the 
 same as by the system of borrow and waste. These two conditions 
 may be expressed by the equation 
 
 V(a + cte/100) = V(a + 6) + Vc 
 
 in which a equals cost of excavating and loading, in cut, per cubic 
 yard; 6, cost of hauling and dumping wasted material, per cubic 
 yard; c, cost of borrow and fill, not rolled, per cubic yard; d, cost 
 of hauling and dumping material taken from cut to fill, per cubic 
 yard hauled, and x length of haul, center of gravity of cut to center 
 of gravity of fill, in feet. 
 
60 
 
 The Engineer in Field and Office 
 
 Eliminating V and a from the equation and reducing, 
 
 = c 
 whence 
 
 x = 100(& + c)/d 
 
 Very likely d will be found practically constant for the entire 
 job, but b and c will need to be estimated separately for each cut 
 and fill, and will no doubt show considerable variation. 
 
 Irregular Street Intersection Area Calculations 
 
 It is almost always necessary to compute the areas of some 
 very irregular street intersections at the time of their improvement. 
 Unless some planning is done beforehand, the proper measurements, 
 which will result in a determination of the area with any degree 
 of precision, are not made in the field. The accompanying diagram 
 of a hypothetical intersection serves to illustrate the use of a special 
 
 Computations of Areas of This Nature Simplified 
 
 curve by which the calculations are simplified, and its employment 
 will make the fieldwork as simple as possible. Only a very brief 
 explanation will make clear the proper procedure to follow in the 
 field. 
 
 Let us assume that the areas of H, I and / are desired. While, 
 of course, it is not exactly true that the curves at the intersection 
 are always arcs of circles, they may be considered so for practical 
 
Municipal Engineering 
 
 61 
 
 purposes, and very close results will be reached if proper averages 
 are taken. 
 
 To compute these areas, the average radius and the internal 
 angle must be determined. Since the ratio of T to E is the same 
 
 
 
 \ 
 
 20 
 
 60 90 
 
 30 40 50 60 70 
 Values of ^ in Degrees 
 
 Enter This Curve with Average of Linear Measurement 
 To Get Average Angle 
 
 as that of C to 2M, as may be seen from the small diagram given 
 with the curve, the one curve is all that is necessary. To determine, 
 for instance, the area marked J, the procedure would be as follows : 
 
 l = ff r2 - 91 
 
 C 23.8 
 
 With this ratio, using the curve, -^ = 43 
 
 . * . A = 86 
 
 5.07 
 Average 2.53 equals "Ratio." 
 
 A 
 
 Then 
 
 or 
 
 16.0 = 16.0 
 tan 43 0.933 
 
 11.9 11.9 
 sin 43 0.680 
 
 or 17.2 
 
 or 17.5 
 34/7 
 
 Average 17.35 
 
62 
 
 The Engineer in Field and Office 
 
 Area inclosed by the tangents and the radii, 17.35 X 16.0 
 
 equals 277.5 
 
 Area of segment of circle, 86/360 X X 17.35 2 equals . 226.0 
 
 J 51.5 sq.ft. 
 5.7 sq.yd. 
 
 If the curve is considered as a parabola, the area might have 
 been calculated in the following manner, but it does not seem at all 
 certain that the result is as near the actual value as is obtained 
 by the method outlined above. 
 
 Area- 2 X 
 
 Area = 
 
 ^= 43.7 sq.ft. 
 J = 4.85 sq.yd. 
 
 It may be seen that the first method is more likely to give a 
 better result than the one based upon the curve being a parabola, 
 because more measurements are utilized. However, either 
 assumption will simplify the computation over the usual method. 
 
 Sidewalks Flushed Over Tops of Parked Automobiles 
 
 The downtown sidewalks as well as the streets in Chicago are 
 flushed every night. To expedite the sidewalk work, there has 
 
 Extension Pipe When Not in Use Folds Over Top of Tank 
 
 recently been added to one of two tank trucks a pipe extension to 
 clear parked automobiles. It is connected to the discharge line 
 
Municipal Engineering 63 
 
 from the pump with a stuffing-box joint and has a knee brace of 
 the same 2i-in. pipe as the remainder of the line. A single outfit 
 can flush the whole 72,000 sq.yd. of area in the territory covered 
 in an 8-hour night at a cost of 20c. per 1000 sq.yd. It is usual, 
 however, to let the two trucks work at the job, although from the 
 
 Parked Automobiles Are Not Disturbed by Sidewalk Flusher 
 
 second one the hose must be dragged behind vehicles near the 
 curb. The remainder of the night's work is to flush the 120,000 
 sq.yd. of pavement. The fan nozzle is 6 in. wide and delivers a 
 stream i in. thick. It is played toward the gutter and carries the 
 dirt and surplus water ahead of it. No complaint of damage to 
 walks or calking has been made. When the second tank is equipped, 
 the connection will be made near the front of the tank, so that 
 there will be no danger of bending the pipe, should the truck run 
 it into something when half-way extended. 
 
 A Modern Intersection for Paved Roads 
 
 It is appreciated by automobile drivers that the loss of momentum 
 and time due to slowing down to turn a 90 corner within the limits 
 of a 50-ft. highway is about equivalent to that required to travel 
 some 1500 ft. on a tangent of similar grade. Another difficulty with 
 the usually designed intersection is the lack of sufficient clear-sight 
 to enable the driver to realize the approach of a motor on an 
 intersecting road. To overcome these difficulties, the design shown 
 in the accompanying illustration has been put forward; and as may 
 
64 
 
 The Engineer in Field and Office 
 
 be seen, within the limits of the proposed highway the clear-sight 
 is 132 ft., though in reality it would be much more than this if the 
 regulations concerning vegetation were enforced. 
 
 While the total area of pavements in the proposed design is 
 1703.6 sq.yd., only 739.6 of this is necessary for the curve connection 
 shown, the remaining 954 sq.yd. constituting 482 lin.ft. of main-line 
 pavement, 18 ft. wide. Pavements 18 ft. wide being ample for two 
 
 A Construction*! 
 
 Proposed Intersection Gives 136-Ft. Clear-Sight 
 
 lines of motor traffic at high speed, they need not be made still 
 wider on curves where speed is necessarily reduced. Likewise, 
 there would seem to be no good reason for widening 10-ft. pave- 
 ments on curves; 15- or 16-ft. pavements, however, should be 
 widened to 18 ft. 
 
 Brick and concrete pavements are generally crowned 2 in. The 
 preservation of this crown at the intersection would prove ob- 
 jectionable, so it should be reduced at the intersection to about i 
 in. and tapered out to the full crown in a distance of about 10 ft. 
 in each direction. 
 
 Sections like G, H, J, K, L, P, Q, R should be built monolithic 
 with the usual convexity of surface at /, K, although J is depressed. 
 
Municipal Engineering 
 
 65 
 
 Areas like H, J, K will come out warped surfaces easily built by an 
 experienced contractor. The 10 construction joints shown should 
 be nothing more than planes of cleavage. Sections like K, E, F, 
 J, which are built last, have their corner elevations fixed by the 
 main pavement. The usual convexity of surface is preserved, 
 therefore, and the inner edge F, J is depressed to meet the required 
 elevation. 
 
 In areas like K, L, E the surface of the ground should be kept 
 about 1 in. below that of the surface of the pavement adjacent. The 
 catchbasins and drains will keep the ground dry. 
 
 Setting Street-Corner Radius Stake 
 
 In setting radius stakes for street corners where the angle of 
 the intersecting streets is not a right angle, the solutions shown in 
 the following sketch save considerable time in finding the correct 
 location for the radius stake. 
 
 Two methods may be used: (1) with transit at E, the inter- 
 section of the curb line and the center line of the intersecting 
 
 Radius 
 State 
 
 u t. ,i 
 
 Diagram for Setting Street-Corner Radius Stake 
 
 street; (2) with transit at F, the intersection of the center line 
 of the two intersecting streets. Considerable time and instrument 
 work are saved by using the method with F as instrument point. 
 For method 1, transit at E, the formulas are: 
 
 x = 
 
 tan A = 
 
 sin B 
 R 
 
 y = R cot i B 
 
 z = R 
 
 sin A 
 
66 
 
 The Engineer in Field and Office 
 
 For method 2, transit at F, the formulas are: 
 
 = 
 x 
 
 a 
 tan o = 
 
 sinB 
 
 -^- 
 tanB 
 
 R + M 
 
 y = R cot\ B 
 
 L = x+ y + 
 R + M 
 
 sine 
 
 Street Assessments in a Hillside Town 
 It is believed that the results obtained by this method for making 
 street improvement assessments in a hilly town with crooked streets 
 and irregular lots are more nearly equitable than those obtained 
 by the ordinary front-foot method. 
 
 Fitting Assessments to a Steep, Crooked Street 
 
 Arrows indicate upgrades. Heavy line shows assessment district boundary. 
 Frontages given in feet and tenths 
 
 The following factors are taken into consideration: (1) Front- 
 age; (2) area; (3) assessed valuation; (4) the benefit or damage 
 to each lot by virtue of its new position with relation to the graded 
 street; (5) correction for over-assessment, where the rates would 
 be excessive. 
 
 The method of making the assessment is as follows : The entire 
 cost to be assessed is distributed in amounts directly proportional 
 to (1) the frontage, (2) the area and (3) the value as shown in 
 Columns 5, 6 and 7 of the table. The mean of these values is then 
 
Municipal Engineering 
 
 67 
 
 computed (Column 8). To this mean a benefit or damage factor 
 is applied varying with the relative position of the lot with reference 
 to the street surface before and after grading. The figure obtained 
 in Column 8 in the case of lots in Class 1 (considerably damaged 
 by grading) are multiplied by ; lots of Class 2 (slightly damaged), 
 by ; lots of Class 3 (neither benefited nor damaged), by 1; lots 
 of Class 4 (slightly benefited), by $; and lots of Class 5 (consider- 
 ably benefited) , by i. The results after this operation are shown 
 in Column 10. A wider and more refined variation could be applied 
 in cases where the conditions warrant it. The sum of the quantities 
 in Colmun 10 is seldom equal to the total cost to be assessed, so 
 that the difference between the sum of Column 10 and the desired 
 total is distributed in proportion to the values found in Column 10 
 (added in the case of the example). The corrected quantities are 
 given in Column 11. An inspection of Column 11 shows that Lots 
 66, 68 and 69 are assessed an amount in excess of 50% of the tax 
 assessor's valuation a percentage which has often been held to 
 be a confiscatory rate. These amounts are then reduced to a sum 
 slightly below 50% of the value, and the excess is then distributed 
 at a uniform rate over the remaining lots, giving the final values 
 shown in Column 12. 
 
 The example given is for the improvement of Central Ave. shown 
 on the diagram (Fig. 1). 
 
 METHOD OF COMPUTING STREET IMPROVEMENTS ACCORDING TO 
 
 FRONTAGE, AREA AND VALUE, WITH BENEFIT 
 
 FACTOR ADJUSTMENT 
 
 Lot 
 
 Frontage, Area, 
 Ft. Sq.Ft. 
 
 Value 
 
 , Cost Distributed According to > 
 Frontage Area Value 
 
 (1) 
 
 (2) 
 
 (3) 
 
 (4) 
 
 (5) 
 
 (6) 
 
 (7) 
 
 16 
 
 20 
 
 59.5 
 
 84.0 
 
 6,900 
 12,000 
 
 $1000 
 800 
 
 $152.26 
 214.96 
 
 $177.94 
 309.45 
 
 $211.05 
 168.84 
 
 21 
 
 0.0 
 
 23,500 
 
 1000 
 
 0.00 
 
 606.01 
 
 211.05 
 
 66 
 
 197.6 
 
 7,100 
 
 400 
 
 505.66 
 
 183.08 
 
 84.42 
 
 68 
 
 80.0 
 
 4,000 
 
 300 
 
 204.72 
 
 103.15 
 
 63.32 
 
 69 
 
 179.8 
 
 3,300 
 
 300 
 
 460.10 
 
 85.10 
 
 63.32 
 
 
 
 Mean of 
 
 Class of 
 
 Col. 8 with 
 
 Col. 10 
 
 Final Cost 
 
 Lot 
 
 
 Cols. 5, 6, 7 
 
 Benefit Benefit Factor 
 
 Adjusted 
 
 Distribution 
 
 (1) 
 
 
 (8) 
 
 (9) 
 
 (10) 
 
 (11) 
 
 (12) 
 
 16 
 
 
 $180.42 
 
 1 
 
 $120.28 
 
 $126.37 
 
 $136.08 
 
 20 
 
 
 231.08 
 
 3 
 
 231.08 
 
 242.33 
 
 260.95 
 
 21 
 
 
 272.35 
 
 4 
 
 317.73 
 
 332.97 
 
 358.20 
 
 66 
 
 
 257.72 
 
 3 
 
 257.72 
 
 270.17 
 
 199.00 
 
 68 
 
 
 123.73 
 
 5 
 
 164.96 
 
 172.94 
 
 149.00 
 
 69 
 
 
 202.84 
 
 2 
 
 169.05 
 
 177.44 
 
 149.00 
 
 Home-Made Portable-Pump for Manholes 
 
 A portable centrifugal-pump outfit to unwater manholes has 
 recently been put together in the shops of the Lincoln Park Com- 
 mission, Chicago, for use in draining the electrical underground 
 
68 The Engineer in Field and Office 
 
 distribution system. The equipment is mounted on low wheels and 
 can be hauled by an automobile or a truck. The 12-hp. 1500-r.p.m. 
 marine-type gasoline engine is direct-connected to a centrifugal 
 pump rated at 500 gal. per min. at 2000 r.p.m. Accessories to the 
 pump and engine are a 23-gal. gasoline tank, 5-gal. automobile 
 radiator, a 20-gal. circulating-system tank and a 66-gal. primary 
 tank. With the available speed, 4-in. intake and 3-in. discharge 
 hose, 300 gal. per min. can be pumped against a 15-ft. head, 
 including suction and discharge, but water may be lifted 30 feet. 
 
 Control of the entire outfit, including the spark and gasoline 
 levers, the outlet and air-vent valves and the valves on the circulating 
 system, are all grouped at the front end of the machine within easy 
 reach of one man. 
 
 Means have been provided for obtaining easy access to any part 
 by making the inclosing walls either hinged or entirely removable. 
 The pump has proved its value in pumping dry a line of ten 3-in. 
 ducts that lie along the shore of Lake Michigan and are arranged 
 to drain from one manhole to another. 
 
 A detailed statement of the cost of constructing this outfit in 
 the shops of the commission is given in the accompanying table. 
 
 COST OF BUILDING EMERGENCY WATER PUMP 
 MATERIAL 
 
 1 marine engine and muffler $90.00 
 
 1 radiator 25.00 
 
 To build truck for engine pump and wheels 225.80 
 
 To install engine on pump truck 69.07 
 
 Painting pump truck 21.54 
 
 To supplying suction hose, valve and fittings 125.89 
 
 Three IJ-ft valves 2.82 
 
 1 cap .10 
 
 12 bolts, various sizes .12 
 
 5 pipe plugs, various sizes .36 
 
 5 bushings, various sizes .45 
 
 12-ft. water pipe, various sizes 2.34 
 
 28 nipples, various sizes 2.24 
 
 4 tees, various sizes .30 
 
 6 unions, various sizes .99 
 
 56 screws and nuts, various sizes 1.00 
 
 19 ells, various sizes 1.61 
 
 6 padlocks, various sizes 660 
 
 Miscellaneous material 24.13 
 
 Total $599.86 
 
 LABOR 
 
 Mechanic, 31 hours at 50c <R-I c en 
 
 Helper, 104 hours at 32c '.'.'.'.'.'.'.'.'.'.'.'. 33.28 
 
 Total 48 7 8 
 
 Garage expense (overhead) 120^85 
 
 Grand total $769.49 
 
 All-Concrete Road Sign 
 
 Competition for the official state-aid road sign for Illinois, which 
 the State Highway .Department announced last June, brought 
 designs from about 75 competitors throughout the United States, 
 
Municipal Engineering 
 
 69 
 
 from California to Massachusetts. It was stipulated that the draw- 
 ings should illustrate the proposed type of sign to be erected along 
 all state-aid roads. 
 
 This Is the Design Which Won the Prize Competition for 
 Illinois Road Signs 
 
 The accompanying illustration shows the successful design. It 
 was selected because of its simplicity and durability, and its evident 
 ability to serve the purpose to which it will be put. The sign is of 
 concrete construction. 
 
 Garbage Collection by Motor Truck 
 
 The City of Los Angeles collects its garbage without cost to the 
 residents, the department being maintained by general taxation. 
 Garbage is delivered under contract to a corporation organized to 
 operate a disposal plant for handling garbage and other refuse 
 produced by the city. The contract stipulates that the company pay 
 the city 51c. per ton delivered for all garbage. 
 
 The city is divided into two zones, in one of which garbage is 
 collected by teams and in the other by motor trucks. For the latter 
 the full-load haul ranges from six to nine miles, averaging 
 approximately eight miles. In this zone a total of about 300 tons 
 of garbage is collected each month by two 2i-ton motor trucks at a 
 
70 The Engineer in Field and Office 
 
 cost of $2.76 per ton. Noncombustibles in both districts are 
 collected by seven 24-ton trucks that bring in a total of about 3300 
 cu.yd. of rubbish per month at a cost of 94c. per cubic yard. 
 
 The cost of operating the trucks ranges from $210 to $250 per 
 month. This includes fuel, driver, lubricants, repairs and deprecia- 
 tion, but is exclusive of the two garbage collectors who accompany 
 each truck. The trucks average two or more loads per day and haul 
 an average of 2| tons per load. Before trucks were adopted, these 
 collections were made by three-horse teams, each of which made a 
 single round trip each day. The use of motor trucks for the outlying 
 districts has proved so satisfactory that the city would not consider 
 a return to the use of teams for this zone. 
 
 The short-haul zone is served by teams using both day and night 
 shifts. The night shift has a monthly average of 2800 tons at a 
 cost of about $1.18 per ton. The day shift averages about 2200 tons 
 per month at a cost of $2.15 per ton. 
 
 Home District for Industrial Workers 
 
 A ninety-acre tract of land on the southern boundary line of 
 the City of San Francisco has been purchased and is being laid out 
 and improved as a district in which the average industrial worker 
 will be able to purchase his own home. Building lots in the 
 residential district are far beyond the reach of the average mechanic ; 
 and as a result the steadiest and best class of workmen have been 
 locating in cities across the bay. This action has tended to attract 
 industries to those cities and away from San Francisco. 
 
 The project contemplates the construction of a large number of 
 small houses which will be sold on such terms that the monthly 
 installments will amount to about the same as the rental such 
 families usually pay, the total cost to be about $2500 or $3000. The 
 improvement of the entire tract at once and the favorable location 
 of lines of transportation, schools, retail-market centers, etc., make 
 it possible to offer the industrial worker a proposition that is 
 expected to have a notable effect on the San Francisco labor problem. 
 
 The single houses are to be, in general, of the bungalow type, 
 containing four rooms and bath and all modern conveniences. The 
 prices fixed on 50 x 100-ft. lots average less than $500. Other 
 quarters for unmarried men are contemplated, and it is expected 
 that the plan will be based on somewhat the same idea as the "com- 
 munity houses" in England's industrial districts. 
 
 The plans contemplate the ultimate accommodation of 15,000 
 people in this district, which is not far from the new Southern 
 Pacific shops, where about 5000 men are employed. The site is 
 
Municipal Engineering 71 
 
 also near the large dry dock under construction at Hunters Point 
 and is within easy reach of what is known as the industrial section 
 of the city. 
 
 Every Culvert is Numbered 
 
 Hamilton County, Ohio, of which Cincinnati is the county seat, 
 places a cast-iron sign with the name of the highway and the number 
 of the culvert on the parapet and wing-walls of every culvert. 
 
 Number of Culvert and Name of Road Help Officials and Tourists 
 
 The accompanying illustration shows a culvert at the intersection 
 of two roads, the Cincinnati-Dayton intercounty highway and the 
 road at right angles, Kemper Road. These signs are a great 
 convenience to tourists and also assist the office record system. 
 
 Street Signs Show House Numbers 
 
 It is sometimes hard, even to one who is acquainted with a city's 
 streets, to tell from the corner signs just how near he is to the 
 particular house number he is seeking. If the seeker is in a street 
 car, the situation is aggravated. Particularly is this so in cities 
 where the house numbers bear no relation to the distance of the 
 cross-streets from a meridian street. The new style of street sign 
 adopted by Cincinnati, Ohio, avoids this difficulty. All streets having 
 car lines are now supplied with the new signs, which show on a 
 separate panel the numbers of the corner houses. This is an 
 admirable advance over the design used for the more important 
 street signs of New York City, which show the crossing street in 
 smaller-size lettering above the indicated street. 
 
72 The Engineer in Field and Office 
 
 Drinking Fountain Attached to Hydrant 
 
 A street drinking fountain supplied from the hose connection of 
 a fire hydrant at Galion, Ohio, is shown by the accompanying view, 
 in which the small vertical pipe at the left supports the fountain 
 and serves as a waste connection to the sewer. The supply line is 
 tapped into a nipple screwed into one of the two hose outlets. This 
 arrangement necessitates the main valve of the hydrant being kept 
 partially open enough at least, to bleed sufficient water for the 
 
 Drinking Fountain on Fire Hydrant 
 
 fountain. A self -draining hydrant, unless accurately adjusted, 
 might waste considerable water if adopted to this scheme, and in any 
 case a valve, too far opened, would have to be closed before steamer 
 connections could be made to the hydrant. 
 
 Spokane Installs Low-Cost Street Signs 
 
 Simple, legible, low-cost street signs are being installed in 
 Spokane, Wash., as shown by the accompanying illustration. Each 
 sign consists of two enameled porcelain plates secured to a creosoted 
 wood base and held by a bracket, clamped to a lamp post. The 
 wood base is so shaped as to make each nameplate rest at a slight 
 
Municipal Engineering 
 
 73 
 
 angle with the vertical, so the street light from above casts no 
 shadow on the nameplate. Each of the four plates attached to one 
 
 Spokane Using Street Signs Like This 
 
 lamp post costs $0.35, and the two brackets together cost $1.15, 
 making a total cost of $2.55 for plates and brackets at a given corner. 
 The cost of the wood and of erection is small. 
 
 White Bridges Can Be Seen at Night 
 
 The practice of painting highway bridges white so as to increase 
 their visibility and thereby decrease possible accidents, is growing 
 
 White Bridge Is Readily Seen 
 
 People who cross this bridge at night who are accustomed to black 
 or red bridges are struck with the ease with which the outlines of 
 
74 The Engineer in Field and Office 
 
 the bridge are noted. In Putnam County, Ohio, several truss bridges 
 have been painted as shown in the view. The end posts of truss 
 and railing are white for their full length but the inner railings and 
 posts up to a height of 4 ft. are painted black as a protection 
 against discoloration. 
 
 Present-Day Water- Works Construction, 
 Maintenance, Operation and Repairs 
 
 Dynamiting a Deep Well 
 
 A water well near Kennett Square, Penn., was "shot" a short 
 short time ago to increase the flow. It was 600 ft. deep, started at 
 the top of a hill of elevation 460 ft. After drilling through 84 ft. 
 of stiff clay and hardpan, solid rock was encountered with successive 
 strata as follows: 
 
 Ft. Ft. 
 
 Sand rock 121.0 Gray granite with green ser- 
 
 Flint rock 90.0 pentine seams 2.0 
 
 Blue granite 17.5 Gray granite 40.0 
 
 White quartz 1.2 Blue granite 3.0 
 
 Gray granite 47.8 Gray granite 72.0 
 
 Blue granite 17.5 Bastard granite 84.0 
 
 Gray granite with quartz seams 10.0 
 
 Blue granite broken 10.0 Total 516.0 
 
 An 8-in. steel casing was sunk to rock and grouted to exclude 
 surface drainage; the hole through the rock was 6 in. At 600 ft. 
 the flow was measured and found to be only 3i gal. per min. To 
 go deeper would mean expensive pumping equipment. It was 
 thought that a discharge of nitroglycerin would shatter some of 
 the water-bearing strata. 
 
 Indications were that the stream supplying the well was about 
 320 ft. below ground level. Just below this point the well was 
 bridged by means of a ball of stiff wire forced to the desired depth. 
 Concrete was placed upon this. A special type of solidified nitro- 
 glycerin which is commonly used for shooting oil wells formed 
 the charge, which consisted of 190 qt. The explosive was packed in 
 10 tubes, 5f in. in diameter and 7 ft. long. These were placed 
 in the well one above another, and the whole was discharged by 
 dropping a jack squib down the well. 
 
 A column of water 500 ft. high was blown from the well, 
 following which the latter was tested. The test pump working 
 continuously for 7 hr. pumped 10,000 gal., which was at the rate 
 of 22 gal. per min. 
 
Water Works 
 
 75 
 
 An Aid to Reservoir-Storage Studies 
 
 In studies of natural or artificial reservoirs for storage purposes, 
 it frequently is necessary to determine the rise or fall in the surface 
 level, due to certain rates of outflow and inflow. If the outflow is 
 not constant for the varying levels, the required rise or fall due 
 to a given inflow is ordinarily arrived at by a laborious trial method 
 until a balance is reached between the various factors. For 
 illustration of the method herein described, let a reservoir of 100 
 sq.mi. be assumed, with a discharge curve as shown by the heavy 
 line in the figure. The theoretical rate of inflow including rainfall 
 
 2 4 6 8 10 12 
 
 Inflow into Reservoir, Thousand Cubic Fee* per Second 
 (Negative Inflow denotes Evaporation or Seepage Loss) 
 
 Chart for Determining Change in Surface Level of Reservoir 
 
 on, and evaporation and seepage from the reservoir is equal to 
 the average rate of outflow from the reservoir plus or minus the 
 rate produced by the rise or fall in the surface level over the given 
 period. By assuming several initial levels within the limit of 
 probable requirements, and several rates of rise and fall during a 
 period of 15 days, the corresponding inflow is determined, upon 
 which the remaining curves in the figure are based. In using 
 such a chart the above process is merely reversed. Given any inflow, 
 and a certain reservoir level at the beginning of the period, the rise 
 or fall during the period may be directly taken off. For a level 
 of 102 and an inflow of 10,000 sec.-ft., the reservoir will rise 1.25 
 ft. during the half month. The chart may be constructed for any 
 shape of outflow curve, and for any period of time, and where there 
 are a considerable number of computations to be made it will prove 
 a time-saver. 
 
76 
 
 The Engineer in Field and Office 
 
 Temperature and Water Consumption 
 
 The accompanying curves show a notable similarity between the 
 number of hours of pumping per month and the average temperature 
 per month for a suburban water plant in Maryland. The plant has 
 
 Temperature and Water Consumption 
 
 five deep-well pumps, 7i mi. of 4- and 6-in. main, and supplies a 
 high-grade suburban development. All services are metered, and 
 there is very little leakage from the mains. 
 
 Liquid Chlorine Superior to Hypochlorite 
 
 Liquid chlorine cost much less and effected more bacterial 
 reduction than hypochlorite and was in other respects more 
 satisfactory on an Illinois installation. With hypochlorite at 7c. 
 and liquid chlorine at 20c. the average cost of hypochlorite treatment 
 for January was $1.07, compared with only $0.28 per 1,000,000 gal 
 for liquid chlorine. 
 
 The average reduction in bacteria count of daily plates made on 
 nutrient agar incubated at 37 C. for 24 hours, was as follows: 
 In January when hypochlorite was used the average raw-water count 
 was 6300 and the filtered- water count was 15. In June, when liquid 
 chlorine was used, the average raw-water count was 7980 and the 
 filtered-water count was 11. In B. Coli tests, the raw water shows 
 100% for each month, while the filtered water shows 1.6% in 
 January and 0.0% in June. These results were obtained by means 
 of 1 c.c. samples in all cases. Also note that while hypochlorite 
 was used 0.46 p.p.m. of available chlorine was applied and while 
 using liquid chlorine 0.22 p.p.m. of chlorine was applied. 
 
 
Water Works 77 
 
 Deep Wells Cost 0.82 Cent per 1000 
 Gallons To Operate 
 
 Costs of maintaining and operating for 16 months five deep wells 
 supplying the University of Illinois were equivalent to an average of 
 $151 per year, or 0.82c. per 1000 gal. The following data were 
 given at the recent meeting of the Illinois section of the American 
 Water- Works Association : 
 
 Capacity Percentage 
 
 , First Cost , of Pump fDa y 
 
 Well Casing Motor and Operating Cost Gal. Pump Was 
 
 Well and Screen and Pump Labor Material per Min. in Operation 
 
 A $559 $375 $172.07 $100.26 60 44 
 
 B 546 813 56.51 2.26 69 
 
 C 699 788 202.73 82.86 81 70 
 
 D 1348 758 113.05 42.93 71 86 
 
 E 891 . 810 147.26 88.08 75 89 
 
 The wells have been drilled about 140 ft. deep into glacial drift, 
 and the water stands about 110 ft. below the surface when pumping 
 is in progress. The pumps had been in use for periods ranging from 
 one to eleven years ; hence the results are believed to represent fairly 
 well the average performance of the pumps during their useful life. 
 
 The chief cause of trouble is the fine sand getting into the well 
 and into the pump. Rods, couplings, working barrel and packing 
 are worn quite rapidly. The conditions under which the pumps 
 work are thought decidedly poor. 
 
 Paper Replaces Hemp for Pipe Joints 
 
 Pipe- joint materials became so scarce on account of the war 
 demands that a paper packing for joints of cast-iron and steel pipes 
 has been tried in Zurich, Switzerland. 
 
 The packing is made of rolls of newspaper, conical in form, 
 6 in. long, i in. to i in. in diameter, nested together and pasted. 
 They are waterproofed by impregnating with tar oil. They are 
 flexible and compressible and can be driven very tight with a calking 
 iron. A f-in. lead joint is poured over the paper, but even without 
 this such joints held a pressure of 750 Ib. per sq.in. after 14 days 
 in water. 
 
 Filter Wash Water Pumped by Compressed Air 
 
 Having on hand two sheet-steel tanks of 29,000-gal. capacity 
 and an air compressor with plenty of off-peak time, the designers 
 of the Lawrenceville, 111., filter plant were enabled to eliminate the 
 purchase of a wash-water pump, the compressor being available to 
 store up sufficient air under pressure. 
 
78 The Engineer in Field and Office 
 
 The plant consists of two rapid filters of 180 sq.ft. filtering area 
 each, with the usual system of strainers fitted for washing at a rate 
 of 2 ft. vertical rise per minute. The two tanks formerly used on 
 the distribution system as storage tanks and pressure equalizers, 
 were available for air storage. 
 
 In washing a filter the procedure is as follows: Starting with 
 the tanks three-fourths full of water, air is pumped in through a 
 2-in. line until a pressure of 25 Ib. per sq.in. has been attained. The 
 air line is then shut off adjacent to the tanks, and the compressor 
 fills an air-storage reservoir of 340 cu.ft. of free air to a pressure 
 of 80 Ib. per sq.in. This storage is on the air line leading to the 
 wash-water tanks. When the required pressure is attained and the 
 storage opened into the line, the filter wash is started. By proper 
 manipulation of the wash-water valve an even wash can be 
 maintained at the required rate. When the filter has been washed, 
 the air pressure is released and the tanks refilled from city service. 
 The only objection reported to the procedure is that the operator 
 may be careless and not give proper attention to the manipulation 
 of the wash-water valve, in which event it is possible to blow up the 
 sand bed. 
 
 New Design of Screen Chamber 
 
 The customary method of removing grass, leaves, sticks, bits of 
 bark and fish from reservoir and lake water supplies is to install 
 either a screen affixed to the pipe or else two screens in series, one 
 of which may be drawn up out of the water for cleaning while the 
 other is in service. The former arangement, which is applicable 
 only to very small depths of water on the screen, is economy 
 itself in first cost, but its use has not always proved so 
 economical; as owing to any one of many causes the screen might 
 not receive the necessary attention at the very time when it was 
 most needed. The latter necessitates a considerable structure to 
 hold the screens in place and house them while being cleaned, 
 besides the trouble and expense of cleaning. 
 
 To obviate these and other difficulties the pressure screen chamber 
 here described was designed. It consists essentially (see 
 illustrations) of a vertical cylinder divided by a horizontal 
 diaphragm into two compartments ; the upper, or inlet, compartment 
 has communication with the lower, or outlet, through a circular 
 opening in the diaphragm and thence through the meshes of an 
 open-ended cylindrical screen resting in the lower compartment, of 
 a diameter nearly that of the opening. The lower end of the screen 
 is concentric with the end of a blowoff pipe with a gate valve on it, 
 
Water Works 
 
 79 
 
 normally closed. The inlet pipe enters the inlet compartment 
 tangentially, while the outlet may leave in any direction relative 
 to that of the inlet, preferably in a radial position. Any flow from 
 the inlet pipe sets up a whirling motion in the water in the upper 
 compartment. In passing through the screen cylinder it has a 
 circumferential as well as a downward motion, which, owing to the 
 
 ..Connection for 
 
 Horizontal Section A-A 
 Rein forced-Concrete Pressure Screen Chamber 
 
 passage of water through the meshes of the screen, diminishes 
 as the bottom of the screen is approached. The result of this is 
 to confine, largely, the foreign matter carried by the water to a 
 central cone the base and height of which are approximately those 
 of the screen. The upturned end of the blowoff pipe being made 
 of nearly as great a diameter as the screen, this results in an 
 accumulation of debris directly in the pipe. When blocking of 
 the screen has progressed to a point at which there is a noticeable 
 loss of head at the screen as measured preferably by a mercury 
 
80 The Engineer in Field and Office 
 
 U-tube or a differential gage the blowoff gate is opened ; the head 
 in the blowoff pipe is then reduced to zero, or nearly so, the hydraulic 
 gradient from reservoir to screen chamber is increased, and the 
 high velocity established is transmitted directly to the water passing 
 diagonally downward over the face of the screen and out the blowoff 
 pipe. Ordinarily, the cleaning of the screen is accomplished in about 
 the time that it takes to open and close the blowoff gate. If it is 
 desired to maintain a considerable continuous flow through the 
 outlet pipe, the blowoff gate need not be opened wide, in which case 
 the operation will require a longer time. Under no conditions is 
 an appreciable amount of water wasted. 
 
 Also incorporated in the design is a hollow segmental brush, 
 for use in cases when the screen does not get attention for such 
 long periods that a deposit of small fish is not readily removed 
 by the flowing water. For the intake pipes of pumping stations the 
 devices are best set in batteries of two, so arranged that one can 
 be put in service while the other is being cleaned. In this case the 
 cleaning is preferably done by jets of high-pressure water directed 
 downward from the edge of the diaphragm across the screen. Where 
 electric power is available, the use of proper contact devices at the 
 point of measurement of the loss of head at the screen will make 
 the entire screening operation automatic, both for gravity and 
 pumping supplies. 
 
 For use with a gravity water-supply the devices have been found 
 to operate most successfully between the heads of 40 and 60 ft., 
 though there is no valid objection to their use at other heads, under 
 certain conditions. The screen chambers are made entirely of 
 reinforced concrete with the exception of the manhole cover, which 
 is of cast iron. 
 
 Geared-Up Gas Engine Drive Pumps 
 
 Formerly, water was supplied in Clarksburg, W. Va., by 
 engine-driven centrifugal low-service pumps and duplex direct- 
 acting high-service pumps, both taking steam from gas-fired boilers. 
 When additional capacity was required it was decided to use pumps 
 driven by gas engines in view of the rapid depletion of the 
 natural-gas supply of the district and the necessity of making the 
 city's fuel wells last as long as possible. The preliminary estimates 
 showed that the gas-engine units would demand only about a third 
 of the fuel needed for the boilers and steam machines. 
 
 The equipment secured after bidding comprised a 4,000,000-gal. 
 centrifugal pump, for 35-ft. head, driven by a 50-hp. engine, and a 
 4,000,000-gal. pump, for 350-ft. head, driven by a 350-hp. engine. 
 
Water Works 81 
 
 The small unit supplies the filter beds, and the larger ones pumps 
 into the city reservoir. The engine speed is stepped up by double 
 helical gears from 200 r.p.m. to 1385. 
 
 During a 10-day continuous run the total gas consumption of 
 both units averaged 82,200 cu.ft. of gas per day; the delivery was 
 held up to 4,100,000 gal. per day against 330- and 30-ft. heads, 
 giving a load of 258.5 water horsepower. The gas comes from the 
 city's wells and is charged up at 6c. per 1000 cu.ft., although the 
 local commercial power rate is 8c. At 6c. the fuel costs $6.96 per 
 hp. per year, or 0.079c. per hp.-hr. 
 
 The complete cost of pumping equipment is reported to have 
 been approximately $17,500; the substructures, superstructure, 
 crane, piping and appurtenances cost complete $13,905, bringing the 
 total to $31,405. The interest, depreciation and upkeep, figured at 
 10% (equivalent to 12% on machinery and 8% on structures), 
 would be $3140, or $12.18 per hp.-year, or 0.138c. per hp.-hr. 
 0.217c. per hp.-hr., exclusive of labor and supplies. 
 
 Electric Tunnel Lights in Closed Box for Safety 
 
 In the construction of the recently completed Cleveland west-side 
 water-works tunnel all lights were ordered to be of such a character 
 that they could not ignite the explosive mixture of gas found in the 
 tunnel. The cap lamps worn by the men are of the storage-battery 
 type, locked and unlocked above ground, but the lights used in 
 construction work itself, which are necessarily larger, are built into 
 a very carefully constructed box. 
 
 The reflectors are "bullet" automobile headlights, each containing 
 a 24-watt lamp that is protected by wire-glass and connected to a 
 90 ampere-hour storage battery set midway of the length of the 
 box. The latter is 13 in. wide, 10 in. high and 23 in. long, outside 
 dimensions, and is lighted and locked above ground the key being 
 kept there. The carpentry work on the boxes is of a very high 
 grade, all joints being tight, serving to keep the explosive gas out 
 of the box as much as possible, in the event of a spark being caused 
 by a loose connection at the battery. 
 
 Air Valves in Large Vented Vaults 
 
 Air valves on the newer wood-stave pipe lines bringing water 
 to Denver, Colo., from the mountain sources are placed in large 
 concrete manholes. Formerly, it was the practice to use open 
 manhole covers, but they have been discontinued in favor of 
 ventilating pipes. The manholes could not always be depended upon, 
 for earth and, in winter, snow and ice might fill the openings. 
 
82 
 
 The Engineer in Field and Office 
 
 For a 2-in. automatic air valve, of which 100 are in use, set on 
 the newer lines one at each summit, 4-in. ventilating pipes are used 
 extended 8 to 10 ft. above the surface. If the supply pipe happens 
 to be laid in a roadway, the ventilating pipe is led off to the side 
 or even inside the fence line to protect it from injury. Small holes, 
 aggregating in area many times the area of the air valve, are bored 
 near the top of the pipe, which is plugged or capped. 
 
 f Ground Line when Manhofe fs Located in Oen Field 
 i 'Ground 
 
 No Collapses with This Design 
 
 The air valve is placed on top of the pipe with a return bend 
 on the outlet, so that any water that may be delivered during the 
 periodical test will not drown out the operator. To facilitate testing, 
 the gate valve is set just above the special casting through which the 
 connection to the wood pipe is made. Also, a hole is drilled in the 
 lower part of the air-valve body for a pet-cock. On opening the 
 pet-cock the float will fall, if held up by air or if it happens to be 
 stuck. If water is holding the float up, the operation of closing the 
 gate valve and opening the pet-cock will make the float work. 
 
 Where these air valves have been installed and an absolutely 
 sure source of air, such as here provided, is assured, no collapses 
 have occurred and the pipes are kept running full, the air being 
 removed as fast as it collects. 
 
Water Works 
 
 Cast-iron Pipe Connection for Wood-Stave Pipe 
 
 The connection of a wood-stave pipe with a concrete structure is 
 a troublesome detail. Quite often the end of the pipe is inserted 
 into a socket left in the concrete. Subsequently the ring left around 
 the pipe is grouted. While this method is still in use it has been 
 the cause of some failures in wooden siphons in Wyoming, for the 
 repair cannot be made easily when it becomes necessary to replace 
 the staves. 
 
 One engineer handles the problem by embedding a cast-iron pipe 
 in the concrete and then fitting the wood pipe over it. To make a 
 water-tight joint and one that permits expansion and contraction, 
 the cast-iron pipe is wrapped with tar-soaked oakum for a distance 
 of 4 ft. Beginning at a point 15 ft. from the end of the pipe, the 
 internal diameter of the wood pipe is increased by tapered staves 
 to fit the outside of the wrapped pipe. 
 
 Pool Floor Forms Are Slotted for Water Stops 
 
 Forms slotted to hold the water stops between adjoining floor 
 blocks were required in laying the floor of a large pool which forms 
 one of the architectural adornments of the Kensico dam of the New 
 York City water supply. This pool, which is 720 ft. long and 135 ft. 
 wide, is partly in cut and partly on a rolled earth fill. It is 
 surrounded by a wall 5 ft. thick, surmounted by cut-stone curbing, 
 and its 8-in. concrete floor is laid on porous material with vitrified 
 pipe underdrains. It was essential to make this floor as near 
 watertight as possible. The floor was laid off in 9-ft. squares with 
 a joint and water stop between adjacent squares. 
 
 Forms for the floor slabs were made in the carpenter shop from 
 6 x 8-in. timbers. A longitudinal groove cut along one side of each 
 of these timbers midway between the top and bottom provided a 
 setting for the steel water-stop strip to be embedded in each block. 
 Each of these form pieces was made separate, and a number of 
 different lengths ranging from a little less than 9 ft. to about 9 ft. 
 11 in. were turned out, as the progress of the work required the 
 form strips to be used sometimes between blocks already cast and 
 sometimes to overlap adjacent blocks. Forms were first set for 
 alternate blocks in each direction, and when these blocks were 
 concreted and the forms removed this left water-stop strips 
 embedded in the first blocks on both sides of the intermediate 
 blocks in each direction. These could then be filled in, leaving 
 holes in alternate rows in each direction on all sides of which the 
 water-stop strip would be sticking out. 
 
84 The Engineer in Field and Office 
 
 As used for the first blocks, the four sides of a form were 
 clamped in place by clips with set screws just outside the forms at 
 the corners. These screws gripped the water-stop strips, which 
 were laid in long lengths, gridiron fashion, over the foundation 
 before the first of the forms were set. The forms were wedged 
 together by driving steel or wood wedges between the clips outside 
 of the forms. Altogether about 350 form pieces were made, and as 
 a rule about thirty blocks were formed with them at one time. The 
 same pieces were used continuously throughout the work, and most 
 of them lasted the job in good shape. 
 
 Steam Jet Clears Coagulant Line 
 
 Steam jets replace water injectors occasionally on the coagulant 
 lines at the filtration plant in Evanston, 111. As designed, the 
 coagulant, after passing the orifice boxes, is forced by water 
 ejectors 450 ft. through a 2-in. lead pipe to the point of application. 
 Considerable trouble from the alum line clogging was experienced, 
 until a steam connection was made. After using steam for 15 or 
 20 min., coagulant is forced through the pipe with water in the 
 usual manner. This cools the inside of the pipe rapidly, causing 
 the scale to break away. Prior to this practice it was necessary to 
 clean the steam line once a week. Once in two months is the 
 interval of time since using the steam jet. 
 
 Calcium Oxide Determined by Sugar Solution 
 
 The following is the method in use in the laboratory of the St. 
 Louis Water Department for the determinations of the water- 
 soluble calcium oxide in quick lime. Approximately 7 grams of 
 lime, contained in a weighing bottle, are dumped into a liter flask 
 containing 500 c.c. of a sugar solution (160 grams per liter). 
 Caking is prevented by causing a whirling of the solution while 
 the sample is being added. The flask is then put on a Camp 
 shaking machine and shaken for 30 minutes. It is then made up 
 to the 1000 c.c. mark with carbon-dioxide-free distilled water, 
 shaken by hand and allowed to stand overnight. Twenty cubic 
 centimeters of this solution are then titrated with tenth-normal 
 hydrochloric acid, using phenolphthalein as the indicator, and the 
 per cent of lime determined. The addition of acid is continued until 
 the first disappearance of the pink color. The color reappears in 
 a short time, but the first disappearance is taken as the end point. 
 
Water Works 
 
 85 
 
 Steel Pipe Line Covered with Concrete 
 
 Old riveted-steel water pipe have been successfully incased in 
 reinforced concrete, and in the light of the present high price of 
 steel plates the work may be of interest to others having pipe lines 
 to replace. 
 
 These details were worked out more particularly for use in 
 covering 10,000 ft. of 24-in. riveted-steel pipe line used as inverted 
 siphons working up to 80 ft. head. This line was laid 30 years ago 
 
 ftott- 
 
 Old Steel Inside Form for New Concrete Pipe 
 
 and is beginning to give way near the ends of the siphons where 
 light weight steel was used on account of low heads. Possibly 95% 
 of the iron is still in the pipe, but it has rusted badly and pitted 
 particularly at the seams, so that it has been necessary to make 
 repairs during the irrigation season. The system not only protects 
 the outside of the pipe and prolongs its life by the jacket of 
 reinforced concrete, but eventually utilizes all the iron in the old 
 pipe, and when it has disappeared leaves a reinforced-concrete pipe 
 without joints, sufficiently strong to carry the pressure. 
 
86 The Engineer in Field and Office 
 
 The forms are constructed of Oregon pine and lined with 26 
 gage black iron, which saves not only the forms but much material, 
 making a smooth outside surface to the finished pipe. Forms for 
 24-in. and larger pipe are made in 8-ft. lengths, while the smaller 
 sizes are made up in 12-ft. lengths. 
 
 After the steel pipe is uncovered it is thoroughly scraped and 
 cleaned with steel brushes. The ground under the pipe is then 
 shaped to the required depth, the pipe being supported on wood 
 blocks until the forms are set. Bedplates of 2 x 4s are then spaced 
 with a template, similar to the end section of the form, on each 
 side of the pipe to support the forms when in place. The wire-mesh 
 reinforcement cut to 50- or 75-ft. lengths is then wound spirally 
 around the pipe and supported where the edges unite by small 
 cement-mortar blocks made in the form of truncated pyramids, li 
 in. high, 2 in. square at the base and I in. at the apex, which is 
 placed next to the pipe. A man with a hand mold will make 2500 or 
 3000 of the small blocks in nine hours. The edges of the mesh rest 
 on the base of the pyramid. The edges of the wire mesh are tied 
 together with No. 24 soft stovepipe wire. 
 
 The forms are then placed on the 2x4s and held rigid by the 
 two i-in. bolts as shown. The wood blocks supporting the pipe are 
 removed, and the pipe is held in, place by a strand of wire and a 
 turnbuckle clamp until the form is filled to a point where the 
 concrete will support the pipe. The concrete is a 1 : 2 : 1 mixture 
 of cement, sand and crushed rock or screened gravel of l-in. 
 maximum size. It is mixed by hand and poured rather wet, being 
 worked to place with a light rod and by tapping the forms with a 
 hammer. In laying the pipe up hill the top openings, as the forms 
 are filled, are closed with covers clamped to place until the concrete 
 sets slightly, when the covers are removed and the surface is well 
 troweled and smoothed. The next morning the forms are removed, 
 and the pipe is painted with neat cement. The pipe is then covered 
 with soil and kept wet for two weeks. 
 
 Twelve men will easily build and backfill 140 ft. of 18-in. pipe, 
 100 ft. of 24-in. or 80 ft. of 30-in. pipe in a day of nine hours. The 
 company is replacing 30-in. steel pipe under 40-ft. head, placed on 
 bridges, with concrete siphons of the same size. 
 
 Friction Loss in Water Pipes and Fittings 
 
 The method of test upon which exponential formulas for the 
 friction loss of head of water flowing through standard pipes and 
 fittings were based, was to let water run from one tank to another, 
 with and without the given pipes and fittings in the connecting line. 
 
Water Works 87 
 
 The velocity was computed after calibrating the free area of the 
 pipe, weighing the water flowing in a given interval, and measuring 
 the difference of level by hook gages. In this way the head-velocity 
 relations were established for various velocities in pipes of i to 
 3 in. nominal size. After plotting these relations on double 
 logarithmic cross-section paper the loss per foot of pipe could be 
 secured. Then a logarithimic plot was made of values of K in the 
 equation 
 
 h = kip 
 
 for the several sizes of pipe. From these the final formula was 
 deduced as 
 
 V 1.75 
 
 h = 0.00685- 
 
 '^1.275 
 
 for water at 68 F. and for velocities of up to 3 ft. per sec., in 
 \- to 3-in. black butt-welded steel pipe. 
 
 Similar studies of galvanized pipes gave the formula 
 
 ,,1.84 
 
 h = 0.00845^06 
 
 In general, the exponent of v increases with the interior roughness 
 of the pipe. 
 
 Increasing the temperature of the water decreased friction-head 
 loss, apparently by changing the coefficient of v of the exponent. 
 The hot-water experiments were not completed. 
 
 For the friction loss of flow at 68 F. through one standard 
 short-radius steam elbow the formula deduced is 
 
 .a.M 
 
 h = O. 
 
 Water-Sample Shipping Case 
 
 A shipping case holding eight 4-oz. water-sample bottles and 
 having an ice capacity to maintain a temperature of 10 C. for 48 
 hours is made of 20-gage galvanized iron, 8 in. wide, 15 in. long 
 and 13 in. high outside dimensions. It is insulated with 1 in. of 
 pressed corkboard and lined with 24-gage galvanized iron, which 
 makes a water-tight joint with the outer casing. The case has 
 two covers: (1) An insulated cover, which has a tapered edge so 
 it will drop easily into place, and a flange to support it; (2) A 
 protecting cover of 22-gage galvanized iron, strengthened at the 
 edge with wire, and provided with hinges and a padlock hasp. The 
 case is carried by means of a rope handle, secured to strap iron 
 
88 The Engineer in Field and Office 
 
 eyelets riveted to the sides of the case. The container for the 
 sample bottles is a can 5 in. in diameter and 10 in. high, made of 
 26-gage galvanized iron, and provided with a slip cover 2-in. deep. 
 The can is held in place by a galvanized iron bond attached just 
 above midheight. The space around the can will hold 13 Ib. of ice. 
 If desired, a liter bottle can be packed in the can instead of eight 
 4-oz. bottles. 
 
 Hunting Faults in Water Mains 
 
 For the last few years the Water Department of the City of 
 Baltimore has been conducting extensive investigations of the 
 condition of underground structures along the city streets. The 
 object is twofold: (1) To repair leaks and save water and (2) to 
 replace old and weak pipes before improved pavements are laid. 
 
 Formerly the method was to tap a pipe at various points and 
 with pitot tubes measure the pressure and the velocity of water 
 flowing and thereby the volume. With all house connections closed 
 between the points tapped the difference between the volumes 
 determined by the pitot tubes gave a measure of the leakage. 
 
 It is now the custom to close all valves on a section of pipe to 
 be tested and, with a triplex pump attached to the line, to subject 
 it to a water pressure of 300 Ib. per sq.in. If the pipe breaks, it 
 is immediately replaced, thus saving the expense of ripping up 
 improved paving a few years hence when the pipe would have 
 eventually broken. A measure of leakage is also gained by this 
 method by noting the drop of pressure per unit of time in the 
 length of pipe tested. 
 
 A Suggestion for Making Water Rates 
 
 Compute the service charge by adding to a price per 1,000 gal. 
 or 100 cu.ft., first X% on the cost of the meter and service pipes 
 where owned by the company, then Y% on the cost of equipment 
 required to meet the peak-load demand of the customer, then $Z 
 for meter reading, billing and collecting, and finally $A to $# for 
 unregistered water. 
 
 The reasons for such a suggested procedure need little exposition. 
 There are two kinds of water- works: (1) The product-dispensing 
 type, which pumps at a small steady rate, or collects as nature 
 furnishes, and delivers out of adequate storage at varying rates; 
 (2) the service type, which maintains pump pressure all the time 
 and has power apparatus enough to meet its peak-load demands. 
 For the first type of water company the Y% mentioned above 
 
Water Works 
 
 89 
 
 becomes insignificant even disappears, for the peak-load equipment 
 consists only of a possible addition to diameter of mains, and even 
 this may be absorbed in the provisions for fire protection. 
 
 Paying attention to the Y percentage in the case of the service 
 type of water-works automatically clears away much of the worry 
 about manufacturers' rates. If an industrial customer does not 
 draw during peak-load hours, Y may disappear so that an attractive 
 rate can be made to him that will still render a respectable profit 
 to the water-works or, where profits are not sought, at least make 
 a more continuous use of plant and increase the spread of 
 investment charges. This would be a development parallel to the 
 success of electric central stations in building up off-peak commercial 
 loads. 
 
 Pressure Constant Under Varying Draft 
 
 The accompanying charts indicate how the pressure in the mains 
 of the Passaic water-supply system is maintained nearly constant, 
 
 Regulator Valve Holds Pressure Constant 
 
 in spite of the varying draft, as shown in the second chart. The 
 amount delivered varies in rate of draft from nothing to about 
 
90 
 
 The Engineer in Field and Office 
 
 8,000,000 gal. per day. As may be seen from the chart, the 
 variations are sudden and irregular. 
 
 Water is taken through a 16-in. regulating valve. The upstream 
 pressure at the connection is about 100 Ib. per sq.in.; it is reduced 
 
 <b 
 
 f H a 3 AV* 
 
 Rate of Draft Varies from to About 8,000,000 Gal per day 
 
 to 30 or 40 pounds. Water passing through the regulator valve is 
 taken from a 51-in. main and delivered to a 30-in. main. The 
 connection was installed in 1908 and has been operated continuously 
 and satisfactorily since that time. 
 
 48-In. Valve Placed on Riser Pipe 
 
 The large elevated water tank at the filtration plant of the 
 Louisville Water Co., Louisville, Ky., was originally installed without 
 a valve between the 48-in. water-main connection and the 52-in. riser 
 pipe. The steel riser pipe recently commenced to show signs of 
 deterioration, and it was decided to put in a valve at the base so that 
 the riser could be cut out for repairs without interference with the 
 connecting mains. 
 
Water Works 
 
 91 
 
 The method of procedure was as follows: The expansion- joint 
 connection at the cylindrical bottom of the tank was fixed so that 
 
 Placing 48-Inch Valve in Water-Tank Riser Pipe 
 
 there would be no movement. This was done by taking out every 
 other bolt in the flange connection and inserting plates of steel 
 which would completely prevent the riser pipe from moving. 
 
 Large Reservoir to be Sealed by Sluicing 
 
 What is probably the largest task of reservoir-bottom sealing 
 ever attempted has been undertaken by Seattle, Wash. The reservoir 
 to be sealed has an area of about 200 acres. The foundations of the 
 dam across Cedar River which forms the reservoir are on bed-rock. 
 
92 The Engineer in Field and Office 
 
 However, for a distance of over a mile, the north bank and the bed 
 of Cedar River show a considerable leak, which appears through 
 4000 ft. of gravel in about sixteen days. 
 
 Drilling in the neighborhood of Cedar Lake has shown at least 
 8,000,000 cu.ft. of excellent clay, and drilling in the lake itself has 
 shown that the greater part of the material on which it rests is 
 blue clay, although the north bank of the lake has naturally silted 
 against material similar to that which is now to be treated. The 
 waters of Cedar River running into the lake are absolutely clear 
 almost the entire year, and at such times as they are not clear the 
 silt all settles in the lake so that the new basin cannot seal of itself. 
 
 A pump with a capacity of 4000 gal. per min. is being installed, 
 and this is to be connected to about one mile of 16-in. pipe, which 
 will carry the water to an elevation of approximately 350 ft. for 
 the sluicing out of the clay bed which has recently been discovered. 
 The material will be carried over grizzlies, the bars of which will 
 be set close, as only the fine material is required. This will be 
 carried back to the north bank of the river and along the distance 
 to be treated. The bank is steep, and a considerable amount of 
 material has to be sluiced into the river bottom in order to get 
 the proper grade for silt to remain on the surface. The water, 
 with clay in suspension, under the 350-ft. head above mentioned, will 
 be used in sluicing the gravel from the bank and in this way will be 
 incorporated with the gravel at the bank, the intention being to use 
 about one part of clay to three or four parts of gravel. The first 
 thousand feet next to the new dam will be treated first. 
 
 The present rate of seepage of the water is being carefully 
 measured and a recording gage is being installed which will give the 
 seepage from time to time as the sealing proceeds. 
 
 Interesting Solutions of Problems in 
 Sewer Construction 
 
 Two Sewers Laid in One Trench 
 
 Two sewers have been constructed in one trench in Cambridge, 
 Mass., since 1889, ranging in a great variety of shapes and sizes 
 from a storm sewer 5 ft. 8 in. by 6 ft. over an 8-in. sanitary sewer 
 to a 24-in. storm sewer over a 24 x 26-in. sanitary sewer. 
 
 In constructing the manhole no deflection in the alignment of 
 the upper sewer is made, as the manhole is built to keep the flow 
 separate. and yet to give access to both sewers by constructing a 
 removable bottom or floor slab in the upper chamber. In order to 
 
Sewers 
 
 93 
 
 inspect and clean the lower sewer, it is necessary only to tilt up the 
 floor slab by means of the two-ring bolts. This would usually be 
 done when nothing was running in the storm sewer. 
 
 The drawing shows a rather interesting example of this type of 
 construction on account of the unusual distance between the two 
 sewers. Ordinarily, they are only about 2 ft. or less apart, thus 
 
 SBCT.ONAL M_AN OF MANHOLE 
 
 CROSS -SECTION 
 
 THROUGH SEWER 
 
 CROSS -SECTION 
 THROUGH MANHOLE 
 
 No Deflection in Alignment at Manholes 
 
 reducing the depth of the lower chamber and increasing the 
 accessibility of the lower sewer. This style of "two-story" manholes 
 has given excellent satisfaction, being convenient as well as 
 inexpensive. 
 
 On the other hand, in the plans for the sewerage system of New 
 Hartford, N. Y., the storm-water sewer was placed below the grade 
 of the sanitary sewer, and with porous joints, to lower the ground 
 water, thus enabling easier construction of the sanitary sewer and 
 greater security against leakage, for the joints were made with 
 
94 
 
 The Engineer in Field and Office 
 
 jute and cement. For good foundation the sanitary sewer was laid 
 on a shelf or shoulder cut in the side of the trench made for the 
 lower sewer after that was laid and covered. The invert of the 
 sanitary sewer was at the same elevation as the top of the other. 
 Both have been continuously in operation and without trouble of 
 any kind. 
 
 Combined Sanitary and Storm Sewers 
 
 The proposed sanitary and storm trunk sewers at Flint, Mich., 
 will be combined in one structure except where it is necessary to 
 
 Cross-Section of Storm and Sanitary Sewers 
 
 have a manhole on the sanitary portion. At such intervals the 
 following methods are used: 
 

 Sewers 
 
 95 
 
 On a tangent a double reverse curve of 100-ft. radius is made 
 in the storm-sewer portion only, thus separating in plan the two 
 sewers a sufficient distance to permit the building of a manhole over 
 the sanitary sewer. 
 
 At all angles in the alignment of the sewer a simple curve of 
 50-ft. radius is made in the storm-sewer portion only. The sanitary 
 sewer is carried a sufficient distance beyond the P.C. and P.T. of 
 
 Between 
 Manholes 
 
 How Provision Is Made for Manholes 
 
 the storm sewer to permit the building of two manholes on the 
 sanitary sewer in case the deflection angle of the sewer line is 
 betwen 45 and 90, and one manhole in case the deflection angle is 
 45 or less. 
 
 The type of construction proposed for that portion of the trunk 
 line in which it becomes necessary to separate in profile the two 
 sewers is illustrated. The maximum depth of sewer is 33 ft., and the 
 minimum depth is 15 feet. 
 
 Calk Sewer Joints Under Some Conditions 
 
 Many engineers continue to construct storm sewers with open 
 joints, basing their practice on the theory that the sewer is to 
 remove surface water and that there is a further advantage gained 
 by allowing all the water possible to enter the sewer by seepage 
 through the open joints. 
 
 For some time the City of Cadillac has experienced difficulty 
 in discharging the storm water through a 24-in. sewer that carries 
 the surface water from a portion of the city. Several had "satisfied" 
 themselves that it was being blocked by the accumulation of tar from 
 the local gas plant, which discharged its waste water near this 
 point. A thorough investigation made during the past winter showed 
 
96 
 
 The Engineer in Field and Office 
 
 the necessity of digging up the sewer. A profile taken of the sewer 
 as found indicated that there was a vertical settlement of 4.79 ft. at 
 a distance of 40 ft. from the manhole on an intersecting street. No 
 variation horizontally was noted. 
 
 The sewer was laid on a small grade through low sandy soil. 
 Due to the fact that it received a large amount of water during 
 storms and spring thaws, there was a head of water sufficient to 
 force through the open joints. The intermittent rise and fall of 
 water surrounding the pipe washed sand through the open joints 
 
 Open Joints Caused This Sewer to Settle 
 
 into the sewer. This process, continued for a period of years, has 
 caused the pipe to settle, thereby increasing the openings in the 
 joints and completely undermining the sewer until it had settled 
 more than two and one-third times its diameter. 
 
 Some lengths of the pipe were nearly filled with sand, but no 
 evidence of an accumulation of tar was found. Most of the pipe 
 was removed from the trench and relaid with joints calked with 
 oakum and filled with cement mortar. 
 
 Measuring, Locating and Stopping Sewer Leaks 
 
 When the sewer system built for Bakersfield, Calif., in 1913-14 
 was completed, one line, comprising about 6600 ft. of 10-, 12- and 
 14-in. vitrified pipe, was found to be leaking badly. This line is 
 located in low, flat ground, and the sewer, throughout most of its 
 length, is covered by groundwater to a depth varying with the 
 seasons of the year. The exact amount of leakage into the line was 
 readily determined, owing to the fact that this sewer empties into 
 a concrete-lined reservoir, from which the sewage is pumped to a 
 gravity outfall sewer. 
 
 SERIES OF LEAKAGE MEASUREMENTS MADE 
 
 From' measurements extending over a period of 24 hours in 
 February, 1914, it was found that the leakage amounted to 70,500 
 
Sewers 97 
 
 gal. in 24 hours. At the time of this test, the groundwater was 
 probably slightly above the mean stage. On Oct. 13, 1914, with the 
 groundwater near its lowest level, the leakage was 39,075 gal. in 
 24 hours. From observations on the level of the groundwater at 
 various points along the line of the sewer it was determined that 
 infiltration was taking place at an average rate of 6.83 gal. per 
 lin.ft. of submerged joint. 
 
 On May 11 and 12, 1915, a similar test was made. It was 
 estimated that the top of the pipe was covered to an average depth 
 of 3 in. throughout its whole length. The flow at this time amounted 
 to over 121,000 gal. in 24 hours, giving a leakage of 15 gal. per lin.ft. 
 of joint in 24 hours. 
 
 The method of repairing was as follows: First, the trench was 
 opened and the pipe uncovered down to about its middle. The soil 
 was then scooped out entirely around the pipe at each joint, leaving 
 a series of oval-shaped depressions beneath the pipe. In the majority 
 of instances the groundwater was at such a height that the 
 depressions beneath the joints were only partly filled with water. 
 In other cases the groundwater was high enough to render pumping 
 necessary, certain portions of the line being entirely covered by 
 water. As the soil at the depth of the pipe was almost pure sand, 
 the flow of water into the trench was very great, and sheeting 
 had to be done with considerable care. For the most part, ordinary 
 2-in. pine lumber was used. 
 
 After the joints for a distance of one block were exposed as 
 described (or for a less distance when pumping was required), the 
 pipe was tightly plugged in the manhole at the lower end of the 
 block. Water was then introduced into the pipe above and allowed 
 to flow down until the block of uncovered pipe was entirely filled. 
 During the filling of the pipe a man was stationed in the manhole 
 at the upper end of the block. As the stream flowed past him, he 
 slowly sprinkled red aniline dye into the water, which was thus 
 colored a bright red. This water, trickling into the little pools 
 below the joints, revealed all the leaks, even the very small ones. 
 The defective joints were marked as found, after which the pipe was 
 emptied and the trench allowed to drain if, as was frequently the 
 case, it became partly filled by the leakage from the pipe. 
 
 The defective joints were then carefully cleaned, and a thick 
 collar of rich cement mortar was applied directly over the old joint. 
 A strip of muslin about 9 in. wide was tied snugly over the cement 
 collar to prevent its falling away from the pipe or being washed 
 
98 The Engineer in Field and Office 
 
 out of the joint by groundwater. It was found that fresh joints 
 protected by this means were not injured by exposure to water 
 where there was no current. Where water came into the trench in 
 a quantity sufficient to make an appreciable current, no chances 
 were taken, and it was kept down by pumping. 
 
 After the cement mortar had had time to set hard, the pipe was 
 again filled with water, colored as before, and any leaks remaining 
 were repaired and the trench backfilled. After the repair of the 
 line was completed, several measurements of the infiltration were 
 taken. A comparison of the infiltration before and after the repair 
 may be interesting: 
 
 Estimated Rate per 
 
 Total Leakage, Lin.Ft. of Joint 
 
 DATE Gal. Submerged, per 24 Hr. 
 Before Repairing: 
 
 Oct. 13,1914 39,075 9.6 
 
 May 12, 1915 121,000 15.0 
 
 After Repairing: 
 
 Dec. 29, 1915, to Jan. 10, 1916, 12 days 1,200 per day 0.3 
 
 Feb. 10, 1916 12,000 1.5 
 
 Zinc Balls Clean Sewers 
 
 Some years ago a pipe sewer system was constructed in 
 Owensboro, Ky. It was stipulated in the specifications that a ball 
 2 in. smaller than the bore of the pipe should pass through without 
 lodging. In making this test on a certain section of sewer, the ball 
 became lodged and had to be flushed to the manhole below. When 
 the ball appeared in the manhole, it was found carrying a half brick 
 before it. Appreciating the significance of this accidental discovery, 
 
 FLOW 
 
 4 
 
 
 How the Ball and Water Clean the Sewer 
 
 this principle was applied to the cleaning of sewers. The writer 
 for a number of years has used this method with excellent results. 
 It is not successful where roots are encountered, but where silt and 
 debris have collected in the sewer due to the absence of flush tanks 
 and catchbasins, or where the latter have been allowed to fill this 
 plan has been found to be cheaper than the drag or bucket method 
 and entirely satisfactory. 
 
Sewers 
 
 When a sewer is flushed without a ball ahead of the stream of 
 water, the sand or silt is pushed forward by the flow of water and 
 the outlet is choked, thereby causing the water to back up and so 
 lose its nozzle pressure ; when a ball is used ahead of the water, the 
 outlet is kept partly open, thus utilizing the pressure. 
 
 If the sewer is badly choked, a ball 5 to 10 in. smaller than 
 the diameter of the pipe is placed in the sewer at the manhole and 
 a stream of water applied behind the ball until it appears at the 
 manhole below; the deposit is removed from the manhole, and a 
 larger ball is then started from the manhole above and carried 
 through as before. This plan is repeated until the sewer is clean. 
 To insure a clean sewer, the last ball to pass through should be 2 in. 
 smaller than the sewer. Where sewers are not badly choked, the 
 first ball may be large, the size depending on the condition of the 
 sewer. The ball should float and should be as light as is consistent 
 with strength. Those used with best results are hollow and made of 
 two thicknesses of No. 24 gage zinc, the seams being set at right 
 angles. The sizes run from 4 to 22 in. Wooden balls have not 
 proved satisfactory. 
 
 A fork or screen with a sandbag directly in front of it should be 
 placed at the inlet end of the lower manhole. This is to prevent the 
 ball, together with the silt expelled from the cleaned sewer, from 
 escaping into the next section of sewer. A line of sewer should 
 of course be cleaned in sections, beginning at the upper manhole. 
 
 Last year an abandoned sewer of 15-in. diameter was found to 
 be almost filled with silt, there being a space of about 2 in. only at 
 the top to allow passage of water. In cleaning this a 4-in. ball 
 was first, and last a 13-in. ball. With the aid of these balls, 5 cu.yd. 
 of sand was removed from this sewer in four hours. 
 
 River Outlet for Combined Sewers 
 
 In connection with a recently published report on sewerage 
 improvements at Davenport, Iowa, a sketch for typical outlets to 
 the Mississippi River was included which is reproduced herewith. 
 The general scheme is sewage disposal by dilution. Where the 
 inverts of the mouths of the various outlet sewers would be above 
 ordinary water level a run of cast-iron pipe would take the 
 dry-weather sewage to a submerged outlet. Where submerged 
 dry-weather flow outlets are impracticable, vertical bar screens 
 
100 
 
 The Engineer in Field and Office 
 
 might be installed in the future; but these are to be avoided 
 where and as long as possible on account of the trouble and 
 
 Ordinary 
 
 Securely anchored 
 Mtssissippr MVE* 
 
 Shore Line 
 
 Proposed River Outlet for Sewage Disposal by Dilution 
 at Davenport, Iowa 
 
 expense of cleaning the screens. It is thought that complete 
 disposal by dilution will be practicable at most of the outlets. 
 
 What Engineers are Doing in the Fields of Flood 
 Control, Irrigation and Hydraulics 
 
 Design of Flood-Retarding Reservoirs 
 
 A problem often encountered in flood-prevention studies is to 
 determine how the flood flow of a stream will be affected by the 
 construction of a retarding reservoir. The nature of this problem 
 and the usual method of solving it have been stated as follows: 
 The rate of outflow from the basin in a flood depends on the 
 height to which the basin is flooded. This height in turn depends 
 on the volume stored, which is the difference between the inflow 
 and the outflow. Thus the quantities involved are inter-related. 
 The problem of computing the outflow had to be solved by trial 
 and error. This method of working is inconvenient and laborious. 
 It may be avoided by the use of the solution given below. 
 
 Notation: t = any short interval of time during the flood; 
 o = rate of outflow from reservoir at any instant, or during 
 interval t; O = total or accumulated outflow up to the beginning 
 of interval t; S total quantity of water stored in reservoir at 
 any instant, or at the middle of interval t. 
 
 Given: (a) The original time-flow curve or flood-hydrograph 
 of the stream, giving the rate of inflow into the proposed reservoir 
 
Irrigation and Hydraulics 
 
 at each instant during the flood considered, (b) The depth-storage 
 curve of the reservoir, giving the total quantity S of the water 
 stored in the reservoir when the surface is at any given elevation, 
 (c) The depth-outflow curve of the reservoir, giving the rate o 
 of the outflow from the reservoir when the water surface is at 
 any given elevation. This curve will be approximately parabolic 
 if the outlet is a tunnel. 
 
 Required: The new time-flow curve for the stream as modified 
 by the proposed reservoir, giving the rate o of the outflow which 
 would pass from the reservoir during each instant of the flood 
 considered. 
 
 Solution: From the original time-flow curve of the stream plot 
 a curve of accumulated inflow at successive instants during the 
 flood. This curve is the "mass curve" for the stream during the 
 flood considered. Erect ordinates to this curve, spaced at a uniform 
 time interval I so small that the curve will not vary sensibly from 
 a straight line between ordinates. 
 
 Using the depth-storage and depth-outflow curves, construct a 
 storage-outflow curve for the reservoir and on the same sheet 
 construct another curve whose ordinate corresponding to any outflow 
 o is S %ot- 
 
 Outflow Rate 
 
 Storage-Outflow Curve Can Be Plotted from Accumulated- 
 Flow Curves 
 
 If the accumulated outflow O is given at the beginning of any 
 time interval t, the outflow curve may be extended through that 
 time interval without the use of trial and error methods by taking 
 from the first curve the outflow rate o corresponding to the value 
 of the quantity S + \ot as scaled from the middle of the time 
 interval t in Fig. 1, and multiplying this rate by t to obtain the 
 outflow ot during the interval. The method applies without change 
 
^ e ? C^ V D *>" 
 
 i a A ft -^ ^i^n 
 
 "^ ; ;; The Engineer in Field and Office 
 
 to the first time interval of the flood where O is zero. The 
 operations may be carried out in tabular form if desired, without 
 drawing the curves. 
 
 When the accumulated-outflow curve has been completed in the 
 manner described, the desired outflow hydrograph of the stream may 
 be readily obtained from it. 
 
 Small Wells Help Drain Irrigated Land 
 
 Rising wells or boreholes sunk below the level of tile drains 
 may materially assist the drainage of irrigated lands that are 
 underlain by shale. This applies particularly to such lands in 
 the Rocky Mountain States, where the water in the shale is under 
 pressure and where methods employed in other sections of the 
 country have not proved successful. Deep tile drains are required, 
 not less than 6 ft., and as much as 8 ft. deep in many cases. The 
 depth to the water-carrying strata, however, is much too great for 
 ditching; and as pressure conditions exist in these strata, the 
 sinking of wells permits the water to rise into the drains. 
 
 Owing to the character of flow in shale ground, the area of 
 influence of a relief well is not large, and from two to six wells 
 per 100 ft. of trench may be necessary. Their maximum depth 
 is usually 20 ft. below the drains, and in general the flow is 
 encountered at a depth of about 15 ft. In most cases a 2-in. hole 
 is sufficient to care for the water. 
 
 The well should be located near the end of a tile, and one 
 end of the tile then chipped so as to leave a 2-in. hole over the 
 well. If the banks will not stand and the wells must be driven 
 as the tile-laying progresses, the well should be a few inches to 
 one side of the drain and connected to the hole in the latter 
 by placing a half -tile over the well. If the well is directly under 
 the tile, it is likely to be closed by sediment washing into it, 
 especially if the flow is weak. 
 
 Modified Pitot Gives High Accuracy 
 
 The pitot tube has long been used as a device for measuring 
 the flow of liquids and gases, but only when used with the utmost 
 care have the results proved uniform. Many experimenters have 
 worked with modified forms in the endeavor to reduce the variation 
 in results, but it is evident not only that the data obtained are 
 variable in the hands of different men, but that the same tube 
 may have different coefficients. 
 
Irrigation and Hydraulics 
 
 103 
 
 In order to correct this latter defect the "Hydraulic Shunt-Flow 
 Tube," was devised. This device is a tube so arranged that it 
 may be introduced into the stream with the tip directed against 
 the flow and yet maintain at the tip the same pressure that 
 existed before the introduction of the tube. The water flows into 
 this tube and may be shunted into a small container and weighed, 
 leaving the velocity undisturbed from the normal. 
 
 Valve 
 
 Common' Pitot Tube 
 FIG. I 
 
 Formula: 
 
 V' 
 
 H* Pitot Head. 
 C Coefficeni- 
 a Acceleration of Gravity 
 
 Hydraulic Shun* 
 (Modification of tfie Pilot Tube) 
 
 Formula: FIG. 2 
 
 Q* flow from Tube 
 A * Area pf lip Opening 
 ( Tip Coefficient 
 
 Almost as Simple as a Pilot Tube 
 
 The velocity of flow at the tip of the tube will be equal to the 
 quantity of water collected in the measuring tank, in a measured 
 time, divided by the area of the tip all quantities being measured 
 in the usual units. It is possible to demonstrate mathematically 
 that turbulent flow should not affect the coefficient of the tip. 
 Theoretically, of course, the tip coefficient should be unity under 
 all conditions, but a series of experiments undertaken with this 
 in view show that it varies less than 1% the pitot coefficient under 
 like condition varying more than 4%. 
 
 Dams of Boulder-Filled Wire Baskets 
 
 Two hydraulic dams recently built in California consist of units, 
 or baskets, of poultry netting filled with coarse gravel and rock 
 These units are built in place and are laid like shingles on a roof. 
 Into the netting are passed very coarse gravel and rock up to the size 
 of a man's head. When a sufficient quantity has been deposited, the 
 top is leveled off with a straightedge, and the selvage edges of the 
 
104 ."."'; The Engineer in Field and Office 
 
 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. 
 
 Discharge Plotted with Novel Curve 
 
 A quick and easy method has been developed for showing the 
 variations in quantity of water passing a given point in a stream. 
 
 The common method of obtaining a continuous chronological 
 record of the fluctuations of the height of water in rivers is by 
 means of a gage with a clock and float attachment. This curve is 
 used in connection with what is known as a "station-rating curve" 
 to determine the amounts of discharge. The usual method of plot- 
 ting a discharge curve is by reading from the station-rating curve 
 the quantities corresponding to critical points on the curve of gage 
 heights and then plotting these results against time on a separate 
 sheet of cross-section paper. 
 
 The method herein described permits plotting the discharge 
 curve on the same paper with the curve of gage heights. It also 
 eliminates the time consumed in reading the gage heights, then 
 referring to the station-rating curve to obtain the discharge, and 
 finally plotting that value. This method presupposes the use of 
 cross-section paper on the recording gage, as is usual with those 
 gages which have a rectilinear rather than a circular movement 
 of the recording pencil. 
 
 It is necessary, first, to plot the station-rating curve with the 
 same scale of heights as is found on the gage-height record. Then 
 draw a straight line from the origin at an angle of 45 with the 
 axes. Next, cut out with a sharp knife the sections lying between 
 the station-rating curve and this 45 line. Finally, paste a piece 
 of cardboard at the bottom of this curve, keeping the lower edge 
 straight and parallel to the horizontal axes. 
 
 This station-rating curve is then superimposed on the gage- 
 height record so that the horizontal lines representing the same 
 gage height coincide. A scale of quantities precisely like that on 
 the station-rating curve is then laid off on the vertical axis of the 
 gage-height curve, the zero of this scale starting at the origin of the 
 station-rating curve. To plot the discharge curve, all that is now 
 necessary is to move the station-rating curve horizontally along a 
 straight-edge until it intersects the curve of gage heights at any 
 point A. Then follow the vertical from this point until it in- 
 
Irrigation and Hydraulics 
 
 105 
 
 tersects the 45 line. This 
 intersection A' is a point 
 on the discharge curve. 
 
 Repeat this operation 
 for all critical points A 
 and then connect the points 
 A' with a smooth, free- 
 hand curve. This gives the 
 discharge curve as in Fig. 
 1 plotted on the same paper 
 with the gage-height rec- 
 ord and corresponding to 
 the time scale thereon. To 
 determine the total dis- 
 charge, planimeter the area 
 under the discharge curve 
 thus plotted. 
 
 That this method is cor- 
 rect is due to the selection 
 and arrangement of the 
 scales of height and quan- 
 tity and to the fact that the 
 ordinate of any point on a 
 straight line passing 
 through the origin and 
 making an angle of 45 
 with the axes equals its 
 abscissa. The operation of 
 this method of plotting will 
 be facilitated if the sta- 
 tion-rating curve is made 
 on tracing cloth and with 
 no vertical or horizontal 
 lines except the axes. The 
 little extra time required in 
 the preparation of the sta- 
 tion-rating curve is many 
 times recovered when plot- 
 ting the discharge curve, 
 especially if, as is often the 
 case, the gage-height curve 
 extends over a long period 
 of time. 
 
106 The Engineer in Field and Office 
 
 Movable Flume on Hydraulic Fill Dam 
 
 During the construction of a large hydraulic fill dam recently 
 completed in the West, considerable time was saved by the use of 
 an inclined runway for the flume from which material was deposited 
 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 along the incline to the desired new position. 
 
 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 intervals toward the 
 axis of the dam. 
 
 The flume box, 12 x 24 in. in section, was built up of li-in. boards 
 and was paved with 6 x 12 x 6-in. hemlock blocks set on end. Im- 
 mediately above the blocks 1 x 6-in. projecting strips were nailed on 
 either 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 ma- 
 terial 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 upstream 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 made on the job. 
 
Railway Civil Engineering 
 
 107 
 
 Hydraulic Elements of Semicircular Flume 
 
 The accompanying curves give the hydraulic elements of 
 semicircular flumes, partly full, in simpler form than curves before 
 published. They can be platted in a few minutes from the elements 
 
 UVl' 
 
 01016 
 0.015 
 0.014. 
 0.013 
 0.012 
 0.011 
 
 6 o.oio 
 
 Z 0.009 
 E0.008 
 C 0.007 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 V 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 \ 
 
 
 t* 
 
 r = 
 
 AREA OF WETTED SE6M 
 SQ 
 HYDRAULIC RADIUS, FT. 
 FLUME NUMBER 
 
 ENT 
 FT 
 
 
 
 
 \ 
 
 
 
 \ 
 
 
 
 
 
 \ 
 
 
 
 
 \ 
 
 "" 
 
 
 
 
 
 \ 
 
 
 
 \ 
 
 , 1 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 Vs 
 
 z. 
 
 
 & 
 
 
 
 
 
 
 
 
 
 
 
 " 
 
 
 
 
 
 
 
 
 
 
 
 
 S 
 
 
 
 \ 
 
 
 
 
 
 
 
 0.005 
 0.004 
 C.003 
 0.002 
 <MX>1 
 
 c 
 
 
 
 
 
 
 
 \ 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 \ 
 
 
 
 
 
 
 
 
 
 
 
 
 
 \ 
 
 
 
 \ 
 
 
 
 
 Z 03 0.4 05 OJ6 0.7 05 0.9 LO U tfc 13 U 15 16 
 
 Curves for Semicircular-Flume Computations 
 
 of circular segments of radius unity, tabulated in almost any book 
 dealing with the flow in circular conduits, by using the commercial 
 number of the flume, which is the length of the curved flume sheet 
 in inches, instead of the diameter. The wetted perimeter, which 
 is seldom used, can be easily found from the area, and the hydraulic 
 radius or the curve can be drawn if desired. 
 
 Practical Pointers for Railway Civil Engineers 
 
 Accurate Stadia Profile at Low Cost 
 
 A stadia profile was run last summer over the Illinois Central 
 R.R. from Champaign to Centralia, 111., a distance of 125 miles, for 
 the railway-engineering department of the University of Illinois. 
 Top-of-rail elevations were desired at intervals of 300 ft. for use in 
 connection with grade-resistance investigations. The requirements 
 that the stations should be tied-in to the mile posts and that the 
 
108 
 
 The Engineer in Field and Office 
 
 linear error in any mile should be not more than 10 ft., which is as 
 close as the mile posts can be indicated on the dynamometer-car 
 charts, were easily met. 
 
 Using 300-ft. sights, there would be 18 readings to each mile; 
 hence, assuming an accuracy in the stadia readings of 1 in 300, the 
 probable error in the length of a mile, according to the method of 
 least squares, would be 1/18, or 4.35 ft., which is well within the 
 allowable limit of error. This made it possible to use the stadia 
 instead of the usual method of chaining. 
 
 In starting the work the rodman held the rod on the top of the 
 rail opposite a mile post, and this point was recorded as Sta. 0. The 
 levelman then paced a distance of 300 ft. and took a stadia reading 
 
 K) 20 JO 4O 50 60 70 SO 9O 100 HO 120 150 
 
 MILES 
 Compensating Tendency in Linear Errors of Stadia 
 
 with the instrument only approximately level. If the paced distance 
 was within 5 ft. of that indicated by the stadia sight, the instrument 
 was finally leveled, and accurate level and stadia readings were 
 taken. Any error in excess of 5 ft. was corrected by making a new 
 set-up. The rodman then advanced to Sta. 3, approximately opposite 
 the instrument, and a level reading was taken. 
 
 The rodman then paced 300 ft. in advance and gave the levelman 
 a trial reading for distance. The levelman signaled the correction 
 necessary to locate Sta. 6, which point was marked on the rail with 
 keel and used as a turning point. The process was repeated at 
 distances of 300 ft. until Sta. 48 was reached. The instrument was 
 set up as nearly midway between Sta. 48 and the mile post as could 
 be determined by eye. Readings to Sta. 48 and to the mile post were 
 made and added to the distance previously covered. In this way the 
 distances between mile posts for 122 of the 125 miles were obtained. 
 
Railway Civil Engineering 109 
 
 The distances between mile posts as given on the Illinois 
 Central's official profile were assumed to be correct, and the differ- 
 ences between these distances and those obtained by stadia meas- 
 urements were considered the errors in the stadia measurements. In 
 very few instances were the mile posts 5280 ft. apart, as indicated 
 by the railroad chaining. The distances between posts varied from 
 5265 to 5285 ft.; hence, not knowing what reading to expect, the 
 observer was entirely unbiased in taking the last reading in each 
 mile. In every case the stadia measurement was made and recorded 
 before the chained value was taken from the profile. 
 
 The maximum error in any one mile was 14 ft. In 7 miles there 
 was no error; in 67% of the miles the error was 5 ft. or less; in 96% 
 it was 10 ft. or less, and the average error per mile was only 4.5 ft. 
 conforming closely to the probable error of 4.35 ft. expected accord- 
 ing to the method of least squares. 
 
 As some of the errors were plus and some were minus, the 
 accumulated error at no point was very large. The total error at 
 the end of each mile has been plotted in the accompanying curve, 
 and it is seen (1) that the largest error was 60 ft. at the end of 
 the fiftieth mile, (2) that the error at the end of the one hundred and 
 twenty-second mile was 12 ft., and (3) that at eight points along 
 the line it was zero. 
 
 Laying Out Crossovers Between Curved Tracks 
 
 Crossovers between non-parallel curved tracks can hardly be 
 located by any exact mathematical formula. Cut-and-try methods 
 on paper on a large scale are the main recourse; but it is very 
 difficult to lay out the flat curves without resort to geometrical con- 
 struction, the lines of which would cover the paper if many trials 
 
 Offset- Scats \ Frocr Fbrrrf^ ' 
 
 Tangent to Curve? 
 Templet Aids in Paper Locations of Turnouts 
 
 were made. A transparent templet like that shown can be used to 
 advantage. The base line can be set tangent to the curve by the 
 offsets, the circle being placed at the desired frog point, and the 
 line of the frog can be laid or pricked off. Thus a number of 
 trials can be made without confusing the drawing by any consider- 
 able number of lines. 
 
110 
 
 The Engineer in Field and Office 
 
 Climate Should Govern Hump Profiles 
 
 Three hump profiles for gravity railroad yards, designed respec- 
 tively for cold, moderate and warm climates, were adopted on the 
 recommendation of the Committee on Yards and Terminals at the 
 recent convention of the American Railway Engineering Association 
 and will be substituted for the profile now in the "Manual." As the 
 drawings indicate, 4% grades, reduced to 1% over the track scales, 
 are recommended for cold climates while for more favorable climates 
 the grades should be lightened or shortened, or both. 
 
 NQ.J, FOR COLD CLIMATE 
 
 
 NO. 2, FOR MODERATE CUMATE 
 
 WftJ. ft?/? VWffM CLIMATE 
 
 Colder Climates Require Steeper Grades 
 
 The committee points out that the problem cannot be solved 
 precisely, since the speed developed by cars depends not only on 
 the type of car, but, with the same type, on the length, whether 
 loaded or empty, the lubrication, efficiency of maintenance, tempera- 
 ture, time standing before being pushed over the hump, head winds, 
 care with which the tracks are brought to and maintained at the 
 profile grade and, lastly, the timidity or assurance of the car rider. 
 
Railway Civil Engineering 
 
 111 
 
 In the estimation of the committee there are these seven salient 
 features in the design of a hump: 
 
 1. A short grade steeper than the approach grade to bunch cars. 
 
 2. A level grade over the summit, these grades to be of such 
 length as to form the tangent to a reverse curve connecting the 
 approach grade with the first descending grade. 
 
 3. A short grade from the summit, to separate the cars quickly 
 and give them the desired speed for weighing. 
 
 4. A light grade over the track scale. 
 
 5. A moderately steep grade, the rate and length depending on 
 the traffic, to the end of the ladders. 
 
 6. A grade through the ladders sufficient to maintain the speed 
 throughout the turnout. 
 
 7. A light grade that will just overcome in the length of the 
 body tracks the speed already acquired. 
 
 Rails Located Before Concrete Is Cast 
 
 The sketch shows a method of setting U-bolts to hold down track 
 rail by which much time was saved over spacing the rail with 
 templets in constructing track for ore bridges at a Buffalo dock. 
 
 Filler 
 
 LEO WALL 
 
 Appro*. 10'- >^ 
 
 of Dock 
 
 Rail Holds Anchor Bolts While Concreting 
 
 Altogether, 2400 ft. of 125-lb. rail was laid in this way. It is anchored 
 by 1-in. U-bolts 24 in. apart, the ends of each bolt passing through 
 a bedplate on which the rails rest, and the nuts on each side holding 
 
112 The Engineer in Field and Office 
 
 down cast-iron clips that retain the rail. To space these anchor 
 bolts, templets of 2-in. pine were first used, but the method was 
 abandoned after the completion of the first 120 ft., because it 
 delayed concreting and there was difficulty in maintaining the bed- 
 plates at the proper elevation. 
 
 The method shown in the sketch, which involved hanging the rail 
 in place before concreting, was substituted. A pipe spreader is 
 used at each anchor, as shown in the sketch, to hold the bolt, bedplate 
 and clips in position. The rail is leveled by the wing-nuts at the top 
 of the hanger rods and lined by slipping the block under each of 
 these nuts one way or the other, before concreting. While the con- 
 crete is still green, the top of the rail is checked for grade. Short 
 1 x 4-in. spreaders from the form studs to the web of the rail hold 
 the latter to line. 
 
 Making Borings for Embankment Subsidence 
 
 Borings were made to test the subsidence of embankments in 
 connection with the Government valuation of the Chicago, St. Paul, 
 Minneapolis & Omaha Ry. The tools used on the work were a 
 carpenter's 2-in. auger, a 2-in. pod auger, a short drill, two bars, 5 
 and 8 ft. long respectively, both of 1-in. drill steel, a supply of 2-in. 
 single-strength pipe and couplings for casing the hole in soil that 
 
 u-"' 
 Extension Bar for Boring Auger 
 
 caved, a pipe lifter and 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 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 
 extension rods were of i-in. round steel, 8 ft. long, with an eye at 
 
Railway Civil Engineering 113 
 
 one end and a hook at the other. As some of the holes 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 connec- 
 tions the rods were disconnected as fast as they were pulled up, and 
 there was no chance for sections to separate while in the hole. 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, then 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 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 
 material 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 the writer had a 3-ft. piece of 
 H-in. pipe (the largest that would go inside the 2-in. casing) 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. 
 
 How Softened Concrete Lining To 
 Tunnel Will Be Repaired 
 
 Plans have been made to repair the concrete lining to the Cascade 
 tunnel of the Great Northern Ry., which has softened due to the 
 formation of sulphur compounds from sulphur in the locomotive 
 gases and the cement. As the lining was put in principally to 
 protect the rock face against disintegration and not for strength, 
 and as the steam locomotives are now superseded by electric trac- 
 tion, it is thought that repairs made now will be permanent. 
 
114 
 
 The Engineer in Field and Office 
 
 The proposed method of repair is as follows: (1) Clean the 
 entire area of sidewalls and arch, removing all disintegrated por- 
 tions. After cleaning, the surface of the concrete is to be sprayed 
 with an alkaline solution for neutralizing the acid in the concrete. 
 
 (2) Drill 2-in. holes where necessary to provide additional drainage. 
 
 (3) Drill 4-in. holes in the arch where necessary and fill cavities 
 existing back of the concrete lining with sand filling or grouting. 
 
 (4) Replace all disintegrated portions of the lining with a coating of 
 concrete by a cement gun. The specifications provide that where 
 the coating is over 3 in. deep it shall be supported by wire mesh 
 cut to fit and fastened to the old concrete by spikes driven into 
 holes drilled in the concrete 24 in. apart. The mixture for use in the 
 cement gun will be one part portland cement and 3i parts sand, 
 mixed dry. 
 
 Turntable for Handling Relay Rails 
 
 The turntable shown in the accompanying sketch is proving a big 
 labor and time saver in handling rails for the new car-repair yard 
 of the Pennsylvania R.R. now under construction at Greenville, New 
 Jersey. 
 
 The 85-lb. rails used are second-hand, and the ball of each is badly 
 worn on one side. Since it is therefore necessary to place the un- 
 worn side on the inside of the track being laid, it happens that many 
 
 r 
 
 Device Saves Much Time in Handling Old Rails 
 
 of the rails have to be turned end for end before placing them. 
 Previous to building the turntable it required considerable maneuv- 
 ering by a gang of at least six men to turn one rail. With the 
 turntable, however, which is set up about 18 ft. from the track 
 being laid, two men can turn a rail with ease. The device was made 
 complete for $8. 
 
Railway Civil Engineering 115 
 
 Open-Tank Creosote Treatment of Timber 
 
 Open-tank treatment of timber is desirable for interurban and 
 the smaller steam railroads that have a number of timber bridges 
 and other timber structures to maintain. Such a plant is convenient 
 for treating fence posts, paving blocks and the like on very short 
 notice. 
 
 The Virginia Railway and Power Co. has operated an open-tank 
 treating plant at Norfolk, Va., since May 1, 1914, using dead oil 
 of coal tar from its own gas-works as a preservative. Water-gas 
 tar was tried as an experiment for a few months and finally 
 abandoned because of the small saving and its doubtful value. 
 
 Yellow pine, mostly of merchantable grade, has been the only 
 species of timber treated in the open tank, and has varied in size 
 from 2 x 4-in. to 14 x 14-in. timber of all lengths. A number 
 of pine poles have also been satisfactorily treated. The penetration 
 obtained has been from 12 to 20 Ib. per cu.ft. of timber. 
 Well-seasoned timber is desirable for open-tank treatment; in the 
 case of green timber it is necessary to keep it in the tanks until 
 it becomes well seasoned from the heated oil. 
 
 The method of treatment is, first, to place the timber in the 
 tank and weight it to prevent floating, and then cover it with 
 oil. The steam is turned on for about eight hours, at approximately 
 100 Ib. pressure, the oil being kept at about 200 F. The steam is 
 then cut off and the oil and timber are allowed to cool over night. 
 The next day the timber is removed from the tank and placed on 
 the storage piles by the derrick boom. 
 
 The following figures give the actual cost of treating at this 
 plant for one month. One foreman (who also operates the electric 
 derrick) at $3, one fireman at $1.50 and four laborers at $1.50 per 
 day are required, working under the bridge supervisor. A total 
 of 39,098 ft. b.m. was treated. The costs were as follows: 
 
 Cost per 
 Item Total M Ft. B.M. 
 
 Dead oil of coal tar. 7375 gal. at 6Jc $479.38 $12.23 
 
 Coal, 6800 Ib. at $3 per ton 9.10 .23 
 
 Labor, including foreman 83.50 2.14 
 
 Maintenance of plant 20.00 .51 
 
 Interest on $3000 investment 15.00 .38 
 
 Total expense for one month $605.98 $15.49 
 
 Average penetration, 19.6 Ib. per cu.ft. of timber. 
 
 The drawing shows the layout of the treating plant. The 
 smaller tank is used for treating only in emergencies. The dead 
 
116 
 
 The Engineer in Field and Office 
 
 oil of coal tar is brought from the gas-works in a 2200-gal. tank-car 
 that is fitted with a section of pipe to allow filling the treating 
 tanks directly. 
 
 .--Tomb Car in Position -for Filling 
 
 SPUR TRACK 
 
 1 
 
 \OPEN TREATING TANK 10'*4O 
 
 \OHhecrtedbyrSfeam Coil 
 covering Bottom of Tern If 
 
 STORAGE TANK +-/<?* 34- X2-Z' 
 
 \ 
 \ 
 
 t 
 
 
 C^\ 
 
 i 
 
 & 
 
 ..-ELECTRIC MOTOR 
 
 vy 
 
 -Hp.Boifa 
 
 TIMBER 
 Treating-Tanks Filled Directly from Car 
 
 1 
 
 I / 
 
 / 
 
 I''' 
 
 -4-t 
 
 This company is very well satisfied with the results obtained. 
 Of course, the company is unable to determine the life of this 
 newly treated timber, but is expecting a life of at least 15 years 
 for bridge timbers, and the same from ties when protected from 
 mechanical wear by tie-plates. 
 
 Over-breakage Payment in Thorough-Cut 
 
 If, in railroad thorough-cut construction, the solid rock 
 excavation be divided into two classes, (1) material within the 
 slopes, (2) breakage, and if prices be fixed on both classes, the 
 price on the latter (breakage) being sufficient to reimburse the 
 contractor for handling this material but not large enough to 
 warrant the excessive use of explosives, the result should be 
 beneficial to both parties to the contract. 
 
 The railroad company will pay no more for the breakage than 
 it is worth in the embankment, and the contractor can use enough 
 powder to break the rock to the slopes, thus avoiding expensive 
 
Railway Civil Engineering 117 
 
 trimming, without being up against the judgment of the engineer 
 as to whether or not he will be paid for the material outside of 
 the slopes. 
 
 This "in the judgment of the engineer" clause about the use of 
 powder and breakage often leads to two bad results: First, loose 
 stones are left hanging to the side of the cut, which should be 
 taken down under construction, but are not and consequently have 
 to be removed under operation. They frequently fall on the 
 roadway and sometimes cause a serious wreck. Second, expensive 
 controversies which may lead to more expensive lawsuits are the 
 logical outcome of this "in the judgment of the engineer" clause. 
 
 Safe Stresses Shown by Broken Timber 
 
 The occasional failure of the stringers of pile bridges has been 
 found to be pretty definitely related to the weight of locomotives 
 operating over them. On the Atchison, Topeka & Santa Fe Ry. 
 two kinds of stringer arrangements exist on the line, heavy and 
 light, and the more frequent failure of stringers in the light floor 
 construction drew attention to this relation. 
 
 All spans are 14 ft., and the stringers are made of Southern 
 (Texas or Louisiana) yellow pine 7 x 16 in. in section, except that 
 Oregon fir is used on lines west of La Junta. In the heavy floors 
 used on main line and important branches there are four pieces 
 per rail, set side by side with 1-in. clear space provided by 
 separator washers on the through-bolts. The light floor used on 
 some branch lines has three-ply stringers. During the past years 
 a number of breakages of sticks in the three-ply stringers has 
 occurred. Only one stick breaks at a time; and thus the breakages 
 do not mean accidents, although they call for immediate repair 
 work. 
 
 It was concluded that reinforcement to four-ply construction is 
 now needed on many of the branch lines. Studies of bending 
 moments in stringers were made to give more certain foundation 
 to this conclusion. Some of the failures are of the longitudinal shear 
 or splitting type, and others are bending-stress failures. The 
 stress investigations, however, were made with reference to bending 
 moment alone. 
 
 The first general fact was that locomotives whose total driver 
 weights exceed 100,000 Ib. for Atlantic, 140,000 Ib. for Pacific and 
 157,000 Ib. for Consolidation engines are likely to produce breakages 
 in three-ply stringers. On the other hand, four-ply stringers gave 
 no trouble anywhere on the system. 
 
118 
 
 The Engineer in Field and Office 
 
 The railway company's standard bridge loading produces on 
 14-ft. span a bending moment equivalent to E-47 loading. It 
 produces an extreme-fiber stress of 1400 Ib. per sq.in. in four-ply 
 and 1860 Ib. per sq.in. in three-ply stringers. Various actual 
 engines used on the line gave the following bending stresses in 
 three-ply construction: 1520, 1780, 1824, 1792 and 1740 Ib. per 
 sq.in. These figures contain no allowance for impact. 
 
 The engines studied include some four-cylinder balanced 
 compounds which produce a low impact effect, while others produce 
 a high counterbalance-weight impact. Partly for this reason it was 
 not possible to make a direct deduction from the facts. The final 
 conclusion, however, was that bending stresses below 1500 Ib. per 
 sq.in. are safe, while loads whose static effect materially exceeds 
 1500 Ib. fiber stress may produce breakages. 
 
 Special Tongs Prevent Rails from Seesawing 
 While Being Handled 
 
 The sketch shows some simple rail tongs which have been 
 developed on the Atchison, Topeka & Santa Fe Ry., and which 
 have given good service. The length of these tongs, 2 ft. 8 in. 
 
 Tongs Hold Rails Steady in Handling 
 
 between grips, is found sufficient to prevent rails from seesawing 
 while being handled by a crane. The main part of the tongs 
 is made from f x 3-in. soft steel, the jaws being hinged on a 
 
Railway Civil Engineering 
 
 119 
 
 |-in. bolt with a 1-in. pipe spreader. Each half of the tongs is 
 connected by a 2-ft. length of -in. chain to a large ring, which is 
 hooked to the hoisting line. 
 
 Concrete Ties in Holland 
 
 An experimental track in which the ties are composed of pairs 
 of concrete blocks connected by transverse steel tie-bars is in 
 service on the Amsterdam-Utrecht line of the Netherlands State 
 Railways, in Holland. In principle the tie resembles the ties tried 
 in this country on the Chicago & Alton Ry., and the cast-iron 
 plate ties that have been used extensively in India. 
 
 Each tie is composed of a pair of reinforced-concrete blocks 
 about 4i x 3 ft. on the base, with a maximum height of about 12 
 in. The top surface is about 36 x 18 in. with flaring ribs to the 
 
 Sect-ional Side Elevo-Hon 
 
 Sectional Erki EtevctKon 
 
 Track with Concrete Blocks and Transverse Steel Channels; 
 Netherlands State Railways 
 
 corners of the base, and its top forms a seat for a pair of 
 wedge-shaped wood blocks. Upon the wood cushions of a pair of 
 concrete blocks rests the ends of a transverse inverted steel channel. 
 Upon this rest the 92-lb. T-rails and rail clamps. 
 
 At each block the rail is held by a pair of deep V-bolts, or 
 stirrups, the loops of which pass through the projecting ends 
 of cast-iron anchors embedded in the concrete. The threaded ends 
 of the bolts pass through the rail clamps. In surfacing track the 
 adjustments are made by loosening these bolts and adjusting the 
 wood wedges, the concrete blocks being left undisturbed, as tamping 
 is liable to result in causing cracks. 
 
 The weight is about 440 Ib. for each block. The weight per 
 lineal foot of track is about 1,500 Ib., including ballast filled over 
 the base of the blocks, but this weight for the experimental track is 
 obtained at the expense of the support of the rail, the spacing 
 being 4 ft. c. to c., or 2 ft. at the rail joints. Such wide spacing 
 of rail supports is undesirable in track construction, and is only 
 introduced to minimize the cost. The experimental track is only 
 
120 The Engineer in Field and Office 
 
 120 ft. long. It carries considerable traffic, but the trains run 
 at low speed, as it is near the city of Utrecht. It has been in 
 service for about two years and is said to be generally in good 
 condition, although cracks have developed in some of the blocks. 
 
 Oiling Flange Saves Rail Wear 
 
 On the New York, Susquehanna & Western Division of the Erie 
 R.R. the rail wear on curves has been reduced two-thirds by the 
 use of flange oilers on the locomotives, and tends to prevent derail- 
 ments. 
 
 For success in the use of the flange oiler a very heavy asphaltum 
 oil must be used. The oil should contain 40 to 60% of asphaltum 
 in solution and be low in grease and paraffin. This heavy oil acts 
 as a lubricant between the wheel flange and the head of the rail 
 when a lighter oil would be forced out. Further than this, the 
 heavy asphaltum oil sticks to the flange and will not work over onto 
 the tread of the driving wheel, as will an oil with a paraffin base. 
 Many of the troubles that have been experienced with flange oilers 
 are due to the use of oil that runs over onto the tread and causes 
 the driving wheel to slip. 
 
 From an operating point of view, the saving in tire turning is 
 even more important than the saving in rail wear. It has been 
 estimated that the cost of tire metal used up, labor and loss of 
 engine service every time a six-driver locomotive has to go to the 
 shop for turning tires on account of sharp flanges represents an 
 outlay of $219. Where freight locomotives not equipped with flange 
 oilers will run 9000 to 12,000 mi. before requiring shopping to have 
 their tires turned, they will run between 25,000 and 42,000 before 
 shopping if equipped with flange oilers. In passenger service, loco- 
 motives that have to be shopped every 15,000 to 25,000 mi. should 
 run 60,000 to 80,000 mi. if equipped with flange oilers. 
 
 Notwithstanding these practical advantages, the flange oiler 
 appears to have as yet comparatively limited use. The reason ap- 
 parently is inertia on the part of the operating force and dislike 
 to equip locomotives with any appliances not absolutely necessary. 
 
 Raise Sunken Bridge Span with Jacks 
 
 A ninety-foot pony truss span belonging to the Evansville & 
 Indianapolis R.R., which was washed out on the White River near 
 Rogers, Ind., was raised clear of the water without difficulty by the 
 method shown in the photographs. The span had been carried 
 
Railway Civil Engineering 
 
 121 
 
 about 1000 ft. downstream, and had landed in an upright position 
 some 50 ft. from the south bank of the river. At low water the 
 top 3 ft. of the trusses was exposed. The span lay in a nearly 
 horizontal position. 
 
 Two gallows frames were erected, one over each hip of the span. 
 The legs of these frames consisted of four pile towers, and the 
 cross beams of six 8 x 16-in. stringers. Each hip joint was hung 
 from a pair of H threaded rods 18 ft. in length. Above the cross 
 
 Nuts Were Used To Adjust Jacking Yoke 
 
 beams each pair of these rods was connected by a timber yoke 
 bearing under nuts screwed down on the rods. The raising was 
 done with two 25-ton jacks, the nuts being used merely to adjust 
 successive grips on the rods. The ends of the span were raised 
 alternately, one jack being set over each joint, and each end being 
 raised about 2 ft. at a time. After the bottom flanges of the 
 floorbeams cleared the water by about 4 in. raising was stopped, 
 two additional bents of falsework placed, and the span dismembered, 
 the pieces being loaded on scows and taken to a repair shop on 
 the north bank of the river. 
 
The Engineer in Field and Offiu 
 
Railway Civil Engineering 123 
 
 Relining a Tunnel Between Trains 
 
 A special concrete car with a high platform and a short tower, 
 a jacking car for moving ahead the heavy forms, and work cars for 
 removing the old timber lining and stone packing behind it, are 
 being used in relining with concrete a single-track tunnel 5023 ft. 
 long on the Union Pacific System at Aspen, Wyo., where about 20 
 train movements take place in the 10-hour day. 
 
 The tunnel being through material that exerts considerable pres- 
 sure on the lining, the forms, made of 12-in. I-beams shaped to the 
 tunnel section and spaced 24 in. apart, are set up first, and the 
 roof load is transferred to them before the old timber is removed. 
 There is a joint in each rib at each side on the springing line be- 
 tween the arch and post sections. To move the ribs forward, a 
 jacking car is spotted at the right point under the roof, and the 
 arch rib is raised from the legs slightly by taking a strain on a 
 double-acting ratchet jack on the car. The legs are released and 
 moved to the next location, the arch section is lowered till it clears 
 the sides and top of the other ribs, and the car pinched ahead till 
 the arch ring can be adjusted and bolted to the legs in their new 
 location. 
 
 A special platform car is used in erecting these ribs, placing the 
 reinforcing and removing the timber and old packing behind it. 
 The platform is extended by hinged wings attached to the sides of 
 the car, thus providing working space for the entire width of the 
 tunnel. The wings are folded down when moving the equipment. 
 
 Another special car is in use placing concrete. On it are 
 mounted a |-cu.yd. mixer and a concrete hoist with a bucket holding 
 one batch. The hoist elevates concrete to a platform 6 ft. below 
 the crown of the arch. From this position it is spouted to place 
 until the level of the platform is reached, after which shoveling is 
 necessary. This car also carries water tanks and the cement. Ag- 
 gregates are supplied in gondola cars and are handled by wheel- 
 barrow. 
 
 By working three openings 200 ft. apart it is possible to keep 
 one gang of men continually employed in form-rib erection, timber 
 removal and excavation, while another gang is busy at concreting. 
 At the same time the carpenters are building forms in the third 
 opening. In this way each unit of the equipment works independ- 
 ently, the sequence of operation in each cycle is maintained at 
 each point, and the work is all carried forward in one direction. 
 
The Engineer in Field and Office 
 
 Wood Block Guards Third-Rail End 
 
 Trouble is sometimes caused by faulty third-rail shoes getting 
 
 below end approaches and thus breaking the insulators and tearing 
 
 up the rail. The accompanying sketch shows how this is prevented 
 
 on one railway property by a wooden block placed in front of a 
 
 Guard To Prevent Third-Rail Shoes from Getting Under the Rail 
 
 third-rail approach and securely nailed to the ties. Sufficient clear, 
 ance is left between the ends of the block and the rail to allow 
 for the expansion of the latter. It has been found that no real 
 harm results if the block accidentally comes in contact with the 
 rail since the leakage is small even in wet weather. 
 
 Photographic Survey of Proposed Route 
 A panoramic photographic survey of the route of the proposed 
 Oregon, California & Eastern Ry. has been made in order to show 
 the character and possibilities of the country to persons interested. 
 The outfit used was a camera capable of making a picture 8 
 in. wide and up to 4 ft. in length. The camera revolves on the 
 head of the tripod and is driven by clockwork so as to cover any 
 desired degree of a circle. From a high point it was possible to 
 cover a distance of 10 to 30 miles. In most cases it was found 
 practicable to set up on a mountain or butte in such a position 
 as to take a view from one valley to another, the points being 
 selected by the engineer. Each picture was begun at about the 
 point where the previous one ended. 
 
 It required 31 pictures, each 3 to 4 ft. long, to cover the entire 
 route. This work consumed 19 days, as much time was taken in 
 getting to and from the view-points. Pictures were taken only 
 under favorable conditions of light, atmosphere and absence of 
 wind, in order to get good results. After the photographs had 
 been made, the chief engineer had a draftsman plot the line of 
 the survey upon each picture, so as to show the cuts, fills, structures 
 and other main features. 
 
Concrete Construction 
 
 125 
 
 Metal Stencil Signs Need No Painting 
 
 Sheet-iron signs with the inscriptions punched out are being in- 
 troduced by the Canadian Pacific Ry. to eliminate the cost of peri- 
 odical painting and lettering. Such signs require nothing but a 
 coat of paint at long intervals, and no painting of letters or numbers. 
 
 Punched ou+ Disks 
 
 SLOW Of 
 
 4-,%'R'ivefs 
 
 Punched out 
 Letters 
 
 ^Order 
 Bridge Number Sign 
 
 Track Signs with Figures Perforated Are Used by 
 Canadian Pacific Railway 
 
 The bridge-number sign, a T Vin. plate, attached to the end of 
 a tie by lagscrews, costs from 75c. to $1. Mile-number signs are 
 similar plates secured to telegraph poles. Such signs should last 
 about 50 years. A wood sign costing $1.25 will last 12 years and has 
 to be painted and lettered every three years at a cost of 75c. ; for 
 a 48-year period its total cost becomes $17. 
 
 Snowplow and whistle signs are fixed on boiler-tube posts. Two 
 6-in. holes are punched in the target for the former sign and a 
 "W" for the latter. Metal "stop" and "slow" signs cost $2.75 each. 
 
 Helpful Suggestions from Recent Concrete 
 Construction 
 
 Caustic Soda and Cement Stop Leaks 
 
 When leaks develop in concrete work it is generally too late in 
 any case to remedy the cause, and the only thing left to do is to 
 stop them, sometimes at the expense of considerable money to the 
 contractor and worry to the engineer. 
 
126 The Engineer in Field and Office 
 
 This is often done by piping the flow to one point, grouting in 
 the pipe while it is passing the water, cutting the pipe off within 
 the surface of the concrete and capping it, after which the hole 
 left over the pipe is plastered up. This is a slow, expensive and 
 puttering way of doing the job. Frequently the pipe rusts, dis- 
 coloring the concrete and sometimes reopening the leak. There is 
 always danger of this if the pipe is exposed to electrolytic action. 
 Leaks may also be calked before plastering with jute, or with lead 
 wool and wood wedges. Jute will only do for small leaks without 
 much pressure, and many engineers do not approve of the use of 
 wood left permanently in the concrete. 
 
 To overcome these objections, the method referred to was de- 
 veloped on the Catskill Aqueduct and Passaic Valley sewer, where 
 leaks which occurred months after the completion of portions of 
 the work caused considerable trouble. The section of concrete 
 around the leak is cut out to a depth of 3 or 4 in. with a chisel 
 so that the hole is larger at the base than at the surface. A small 
 quantity of fresh portland cement is then mixed with a boiling- 
 hot solution of caustic soda into a thick paste, which is applied 
 rapidly with the hands (which should be covered with rubber 
 gloves) to one side of the cavity. The plaster is pressed firmly 
 against the old concrete and held for a minute or more. In this 
 length of time it sets very hard and can only be removed with a 
 chisel. This operation is repeated, following around the sides of 
 the cavity, until a small opening remains, through which the water 
 is now flowing. This small opening is again shaped with a chisel 
 till the bottom is larger than the opening at the surface. Enough 
 freshly mixed paste is then taken in the hand completely to fill this 
 opening, and applied suddenly with one hand, holding the paste in 
 place for a few minutes. If the work has been done well, the leak 
 will be completely closed. 
 
 Practice is required for the successful use of this method, and 
 there are several important points to be carefully observed. The 
 soda must be of the best quality and fresh, very concentrated and 
 mixed with very little water. The mixture must be boiling hot 
 when the cement is added, and the latter must also be perfectly 
 fresh. Very little of the paste should be prepared at one time, as 
 it hardens almost instantly. Just enough of the soda solution should 
 be used to make a stiff paste, which should be mixed very rapidly 
 by kneading it with the hands. 
 
Concrete Construction 127 
 
 One Year's Tests of Field-Made Concrete 
 
 Compression tests of 8 x 16-in. cylinders cast from concrete 
 taken from forms have been made on practically all the work under 
 the jurisdiction of the New York Public Service Commission, in 
 connection with the construction of the new rapid-transit lines 
 in New York City. The results of one year's series of such tests 
 have been collected in the accompanying table, to which have been 
 added for purposes of comparison the compression values prescribed 
 by the final report of the Joint Committee. 
 
 RESULTS OF ONE YEAR'S TESTS ON FIELD-MADE 1:2:4 CONCRETE 
 BY NEW YORK PUBLIC SERVICE COMMISSION* 
 
 No. of No. of Increased 
 
 28 Days, Tests 90 Days, Tests Over Cor- 
 
 Average Repre- Average Repre- responding 
 
 Lb. per sented in Lb. per sented in 2 8 -Day 
 
 Sq.In. Average Sq.In. Average Tests 
 
 Average of all tests 1725 84 2100 59 21% 
 
 Coarse Aggregate: 
 
 Mixed Long Island beach sand 
 
 and gravel 2155 11 2370 8 24% 
 
 Lond Island beach gravel 1880 10 2185 3 18% 
 
 Hudson River limestone 1880 10 2240 10 14% 
 
 Hudson River dolomite 1790 4 2280 3 23% 
 
 Hudson River traprock 1630 16 2035 10 17.5% 
 
 Long Island bank gravel (washed) 1550 31 1990 24 25% 
 
 Fine Aggregates : 
 
 Sand excavated on the work... 1775 9 2285 7 25% 
 
 Long Island beach sand 1690 24 2020 13 15.5% 
 
 Long Island bank sand (washed) 1610 38 2050 30 21% 
 
 Hudson River bank sand 1135 1 1837 1 62% 
 
 Consistency : 
 
 Medium 2220 18 2425 14 10% 
 
 Wet (stiff enough to keep coarse 
 aggregate from settling to 
 
 bottom) 1710 47 2070 39 24.5% 
 
 Very wet (coarse aggregate set- 
 tles to bottom) 1580 13 2300 1 33% 
 
 Extra wet (soupy) 1185 7 1320 6 10% 
 
 Mixer : 
 
 Machine 1750 80 2100 59 21 % 
 
 Hand 1290 4 .. .... 
 
 Joint Committee : 
 
 Granite and traprock 2200 . . .... . . .... 
 
 Gravel, hard limestone, hard 
 
 sandstone 2000 .. .... .. .... 
 
 Soft limestone and sandstone. ... 1500 . . .... . . .... 
 
 *A11 tests of doubtful accuracy have been omitted, and in computing the 
 averages the result of any test that differed more than 50% from the average 
 has been excluded. Each test consists of three specimens. Aggregates wore 
 specification material in every case. Dimensions of specimen cylinders, 8 in. in 
 diameter by 16 in. high. 
 
 How Much Water for Road Concrete? 
 
 The proper amount of water to use in concrete to be placed 
 in concrete roads is slightly more than the amount that will give 
 a maximum strength. This is because the maximum-strength 
 content gives a consistency that is too difficult to work, and a 
 balance between strength and operating facility has to be made. 
 
128 
 
 The Engineer in Field and Office 
 
 Tests were made at the Lewis Institute on a number of 6 x 12-in. 
 compression cylinders, made in mixes ranging from one part cement 
 and nine parts aggregate to one part cement and two parts 
 aggregate. The aggregate consisted of a mixture of sand and 
 pebbles graded in size from the finest particles up to li in., and 
 the same grading was used throughout. 
 
 The tests show that the effect of proportional changes in the 
 mixing water is approximately the same for all mixes of concrete. 
 Therefore a composite curve was drawn to show the average effect. 
 
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 WITH THE 
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 SLOPPY CONCRETE SOMETIMES 
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 70 80 90 100 110 120 130 MO 150 160 170 180 190 ZOO 
 Per Cent, of Water giving Maximum Strength 
 
 How Excess Water Affects Concrete Strength 
 
 This curve is reproduced herewith. In it the ordinates represent 
 the relative strength of concrete expressed as a per cent, of the 
 maximum that can be secured from a given amount of cement 
 and the same aggregate. The abscissas indicate the relative 
 quantity of water used in the mix, considering the amount that gives 
 the maximum strength as 100%. It will be noticed that there are 
 no definite figures given, because the proper amount of water 
 varies with the method of handling and placing the concrete, the 
 condition of the aggregate, the temperature of the outside air 
 and a number of other factors. 
 
 As a rule, the amount of water that gives the maximum strength 
 produces a mix that is too stiff for most purposes, though in 
 cast-concrete products a mix even drier than that which gives the 
 maximum strength is sometimes desirable, because the molds can 
 
Concrete Construction 129 
 
 thus be removed within a short time. The general conditions, 
 however, are shown in the curve. It will be observed that concrete 
 strength increases rapidly with the quantity of water up to the 
 optimum condition. With any further increase in the amount of 
 water there is a rapid falling off of the strength, so that with an 
 amount of water about double that required for the higher strength 
 the concrete has only about 20% of the maximum strength. 
 
 In building concrete roads the consistency which is recommended 
 corresponds to about 105 to 115% of that giving the strongest con- 
 crete. The economies resulting from handling the concrete are more 
 important than securing the maximum possible strength for a given 
 amount of cement. It has been observed that many road contractors 
 insist on using water varying between 130 and 200% of that corre- 
 sponding to the highest strength, with the effect on the strength 
 noted in the curve. Had this curve extended beyond the 200% water, 
 it would have been practically flat, thus indicating that the maximum 
 of damage is caused at that point. 
 
 The proper quantity of water will vary with the quantity of 
 cement and the size and grading of the aggregate, and to a less 
 degree with the nature of the aggregate. The water required for 
 a sand and crushed-stone aggregate is not appreciably different 
 from that required of a sand and pebble mixture, provided the 
 grading of the aggregates is similar. But there is no direct 
 criterion for determining in advance the best quantity of water for 
 
 WATER REQUIRED FOR ROAD CONCRETE 
 
 , Mix N Approximate Mix as Usually Water Required 
 
 Volume of Expressed (Gallons per Sack of 
 
 Aggregate /^-Aggregate N Cement) 
 
 Cement After Mixing Cement Fine Coarse Minimum Maximum 
 
 1 5 1 2 4 6 6J 
 
 1 4i 1 2 3 5f 6| 
 
 14 1 li 3 5| 6 
 
 13 1 11 2i 5 5i 
 
 concrete being placed on a road. The concrete should be mixed 
 so that only a small quantity of free water will appear on the 
 surface after leveling and striking off, which gives concrete of a 
 jelly-like consistency. 
 
 The principal difficulty in the way of attempting to determine 
 in advance the proper quantity of water is due to the fact that 
 aggregates are generally damp, and the degree of dampness is not 
 uniform. In the case of concrete made of sand and pebbles, or 
 sand and crushed stone, well graded in sizes up to 1 in., the 
 accompanying table indicates about the quantity of water that 
 should be used for the mixes commonly employed in concrete roads. 
 It is assumed that the aggregates are in a room-dry condition, 
 which does not always prevail in work. 
 
130 The Engineer in Field and Office 
 
 Effect of Hydrated Lime on Concrete 
 
 The Bureau of Standards some time ago started an exhaustive 
 series of tests looking into the effect of hydrated lime on concrete, 
 as regards strength, consistency, watertightness and workability. 
 A preliminary announcement gives some conclusions, based on six 
 months' tests, as to the effect on strength. The results should be 
 used with caution and hold only for hand-mixed, tamped concrete, 
 of rather dry consistency and stored in a damp closet. There is 
 no evidence at present to show the effect of the hydrate on concrete 
 which is either machine mixed, poured or aged in air, and 
 interpretation of the present conclusion to obtain such information 
 is not justifiable. 
 
 The following conclusions have been reached: (1) The 
 substitution of hydrated lime for cement causes, in general, a 
 diminution of the compressive strength of the concrete. This is 
 most pronounced with 1:2:4 concrete. (2) Hydrated lime causes 
 a less diminution of strength in a 1 : 14 : 3 concrete than in a 1 : 2 : 4. 
 Results indicate that the sizing of the ingredients may be one of 
 the important factors in determining the value of hydrated lime 
 in concrete. (3) At least up to six months, there is no appreciable 
 difference in behavior between high calcium and high magnesian 
 hydrate. (4) The diminution of strength caused by hydrate when 
 1: 14: 3 concrete is stored in air is not nearly so great as when 
 the concrete is stored in the damp closet. 
 
 Link Expansion Joints on Viaduct 
 
 Measurements taken between extremes of temperature for a 
 year on the linked expansion joints of the Colfax-Larimer viaduct 
 in Denver indicate that all joints work as nearly equally as could 
 be hoped for. The structure consists of alternate towers and 
 suspended spans, the latter having lengths one-half the distance 
 between bents and being supported by links upon the overhanging 
 girders of the towers. With favorable results on the structure 
 proper, on which to base the design of the joints in the pavement, 
 the problem was to make provision for movement approximately 
 every 80 ft., in such a way that there would be as little annoyance 
 as possible to traffic. Plates or angles projecting in roadways 
 are somewhat of a nuisance, and the thickness of the asphaltic 
 pavement did not render a built-up joint feasible. 
 
 The- joints adopted have undergone the test of an exceptionally 
 severe winter in Denver, some being pulled apart at least I in. 
 
Concrete Construction 131 
 
 without as yet showing any need of repair; and as for ease of 
 riding, a crack in an asphaltic pavement gives less shock to a 
 vehicle than almost any other form of joint. 
 
 One other point in the design of the viaduct having to do with 
 expansion, which has caused some anxiety, is the laying of sidewalk 
 slabs of 4-in. thickness directly upon the old concrete of the super- 
 structure itself. Although these slabs are completely severed by 
 transverse joints at intervals of about 5 ft., they are monolithic with 
 the curb ; and there was some fear that, being exposed to the atmos- 
 phere, their rates of contraction would be different from that of the 
 
 M 18, Gal Steel 
 21" Wide before 
 Elastic Joint 
 
 Sidewalk Exp. Joint Exp j oint in 
 
 Expansion Joints Are Different at Track, Roadway and Sidewalk 
 
 concrete underneath, which difference might result in surface 
 cracking and possible shattering after long exposure. There was 
 some thought of painting the joint with tar pitch or asphalt paint; 
 but it was finally concluded that this would be ineffective, since the 
 concrete of the underlying superstructure, being more or less lumpy, 
 the painting would not overcome the resistance of the mechanical 
 bond. This possible trouble could have been avoided by making 
 the sidewalk monolithic with the superstructure, but previous 
 experience along this -line showed that it would be impossible to 
 obtain either a surface to grade or a good alignment of the curbing. 
 
 Double Shell Concrete Chimney 
 
 A special arrangement of the interior shell and the use of 
 adjustable steel forms to give an exterior taper are the features of 
 the reinforced-concrete chimney at the plant of the Rockford Paper 
 Box Board Co., Rockford, Illinois. It is 187 ft. high with an 
 interior diameter of 7 ft. throughout. The outside diameter is 10 
 ft. 4 in. at the footing and 9 ft. at the top, with a taper of 
 0.056 in. per foot, commencing at the top of the breeching. The 
 inner shell has been carried nearly to the top in order to protect 
 the outer wall and to improve the draft efficiency 
 
132 
 
 The Engineer in Field and Office 
 
 If the gases are only slightly cooled and come in contact with 
 a relatively thick portion of the outer wall, they heat its inner 
 surface while the exterior may be exposed to very cold weather. 
 As concrete is a poor conductor of heat, this condition results in 
 severe internal stresses, and observations of many chimneys built 
 in this way indicate that the most serious cracks occur about 
 the level of the top of the short interior wall. 
 
 I : : i ! 
 
 Elevation at Breeching 
 
 f .... 7 > ....>,- 
 Plan at Breeching 
 
 22' 1 ^ Plan at Footing 
 
 Concrete Chimney with Inner Shell Extending Full Height of Shaft 
 
 To create a draft in the air space, in order to protect the 
 outer wall from high temperatures and to prevent the collection 
 of soot, openings in the outer wall are made at the base of the 
 air space. The inner wall is made as thin as practicable in order 
 to minimize unequal expansion and is 4 in. thick for its entire 
 height. 
 
 The thickness of the outer wall of the chimney illustrated 
 reduces from 12 in. at the bottom of the air space to 4 in. at 
 
Concrete Construction 133 
 
 the top of this space (beneath the cap). In nontapering chimneys 
 the variation in thickness is made by offsets on the inner side, but 
 in this case the inner side is vertical and the reduction is made 
 by the tapering of the outer side. This taper was given by the 
 use of adjustable steel forms. These were in lifts 2 ft. high, 
 and the diameter was reduced at each lift. The forms were found 
 very flexible, and the same ones used for the stack were made to 
 serve also for the enlarged head, or cap. 
 
 The concrete is a 1:2:4 mix, made with gravel i to 1 in. in 
 size. It was hoisted in buckets in an inside tower, which carried 
 the working platform. The reinforcement consists of steel rods and 
 hoops in each wall, the vertical rods being hooked to the rods in 
 the base of the footing. This footing is built directly upon a stiff 
 clay formation, no piles or other special treatment being required. 
 
 Results of Recent Tests in the Laboratory 
 
 Results of Wood-Decay Investigations 
 
 Field and laboratory studies of the U. S. Forest Service indicate 
 that much more care should be exercised in the selection of timber 
 and in the construction of buildings to avoid conditions favorable 
 to decay. Any one of the following causes may result in rapid de- 
 terioration of the building: (1) Use of green timber, (2) allowing 
 the timber to get wet during construction, (3) allowing the timber 
 to absorb moisture after the building is finished because of leaks 
 or lack of ventilation, (4) use of timber containing too much sap- 
 wood, (5) use of timber which have already started to decay. The 
 avoidance of these conditions will, as a rule, prevent decay. In 
 special cases preservative treatment is necessary, zinc chloride and 
 sodium fluoride being better than creosote for buildings. 
 
 Studies to determine the extent to which lumber is attacked by 
 fungi while seasoning in lumber yards are being continued. Specific 
 cases were studied, showing how sound lumber is infected by partly 
 decayed lumber before shipment is made. Simple rules were formu- 
 lated for restricting the spread of fungus in lumber. Tests to 
 determine the effect of various amounts of resin in the southern 
 pines upon their durability indicate that it does not depend directly 
 upon their resin content. 
 
 About 1500 pieces of wood, representing 50 different species, are 
 under test to determine their relative durability. At the end of 
 
134 The Engineer in Field and Office 
 
 three years, all of the conifers with the exception of cypress, red- 
 wood, yew, and the cedars, have decayed, as have also most of the 
 hardwoods. 
 
 Kiln-Dried Douglas Fir Timbers Tested 
 
 Bending tests were made upon four kiln-dried Douglas fir beams 
 and minor specimens cut from them by the Forest Products Lab- 
 oratory. Beams 1 and 2 were dried under high velocity, low-super- 
 heated steam, at a temperature of 225 F. for a day, 230 F. for the 
 succeeding seven days, and 240 F. for the remaining four days. 
 Beams 3 and 4 were kept at a temperature of 220 F. throughout 
 the run, the steam being superheated for the first five days, when 
 the humidity was reduced to 70%. During the next four days the 
 humidity dropped gradually to 25%, where it was maintained during 
 the remaining seven days. Beams 1 and 2 had a modulus of rupture 
 of 6620 and 4910 Ib. per sq.in. respectively, and beams 3 and 4 a 
 modulus of rupture of 4740 and 6160 Ib. per sq.in. respectively. All 
 beams failed by horizontal shear due to the severe checking. The 
 results are very encouraging for the development of the process 
 for kiln drying Douglas fir beams in structural sizes. 
 
 Zinc Borate Retains Fire-Resisting Power 
 
 The Forest Products Laboratory has just fire-tested a small 
 shingle roof section, painted with a zinc borate paint, which has 
 been exposed to the weather for nearly three years other shingles 
 specially treated with the same paint being used as a control. The 
 results show that the paint had resisted the action of the weather 
 without losing its fire-retarding properties to any marked extent. 
 
 White Paint Saves Gasoline 
 
 In considering the effect of the different types of rays of which 
 light is composed, it is found that the calorific, or heat-producing, 
 rays are conducted by painted or finished objects in widely varying 
 degree. This fact should be studied. When black or dark-colored 
 paints have been used in painting large tanks containing light dis- 
 tillates, rapid absorption of heat takes place, and considerable losses 
 by evaporation are apt to occur. White or light-colored paint should 
 
Laboratory Work 
 
 135 
 
 therefore be used for the finishing coats on oil-storage tanks. 
 Paints presenting a high gloss are, moreover, less absorptive of 
 thermal rays than those presenting a matte surface. 
 
 RISE IN TEMPERATURE OF BENZINE CONTAINED IN SMALL, TANKS 
 
 PAINTED IN VARIOUS COLORS (GLOSS FINISH), WHEN SUBJECTED 
 
 TO HAYS OF CARBON ARC FOR PERIOD OF 15 MINUTES 
 
 COLOR Rise in Deg. 
 
 Tin plate 19.8 
 
 Aluminum paint 20.5 
 
 White paint 22.5 
 
 Light cream paint. . 23.0 
 
 Light pink paint 23.7 
 
 Light blue paint 24.3 
 
 COLOR 
 
 Light gray paint 
 
 Light green paint 
 
 Red iron oxide paint 
 
 Dark Prussian blue paint.. 
 Dark chrome green paint. . 
 Black paint 
 
 Rise in Deg. 
 26.3 
 26.6 
 29.7 
 36.7 
 39.9 
 54.0 
 
 Since white paints faintly tinted have given substantially the 
 same heat-reflecting properties as white paints, the former should be 
 given the preference, as they are more restful to the eye and more 
 durable on long-time exposure. 
 
 The Lead Content of a Leaded-Zinc Paint 
 
 In states requiring the formula to be shown on paint packages, 
 the lead content of all oxides excepting the lowest (under 5%) must 
 
 80 90 100 PbS04\! 
 
 ZnO 
 
 Amounts of Leaded Zinc and Sublimed Lead to Use for 
 Desired Lead Content of Mix 
 
 be stated. In all cases where the lead sulphate is actually basic 
 (Pb 3 S 2 8 ), this is properly given as "basic lead sulphate." On the 
 other hand, if leaded oxide be used in which the lead content is 
 
136 The Engineer in Field and Office 
 
 practically all present as normal lead sulphate (PbSOJ, the pro- 
 priety of the designation may be subject to question. 
 
 In practice it is often necessary or desirable to increase the basic 
 lead sulphate content of the formula over that present in the leaded 
 zinc available for use. Since basic lead sulphate (or sublimed lead) 
 as marketed contains about 5% of zinc oxide, calculation of the 
 required proportions of the two pigments required to yield the 
 relative percentages is a rather complicated process. The accom- 
 panying chart will furnish the required information at a glance. 
 
 The figures to the left indicate the percentages of leaded zinc 
 and those to the right of sublimed lead required to produce the 
 required percentages of ZnO and PbS0 4 indicated at the bottom 
 of the chart. The four diagonal lines represent the several grades 
 of oxide. To find any desired percentages shown in the bottom 
 rows of figures, using any of the oxides shown, follow the perpen- 
 dicular line to its intersection with the proper diagonal; the required 
 percentages of that oxide and sublimed lead will then be found on 
 the horizontal line to the left and right respectively. For example: 
 Desired percentages 50 each, using a 35% leaded oxide. The 50-50 
 perpendicular intersects the 35% diagonal at the horizontal line, 
 which indicates at the left 76% leaded zinc, and at the right 24% 
 sublimed white lead. The desired percentages will therefore be 
 obtained by using 76 Ib. of the former to 24 Ib. of the latter. 
 
 Tinned Copper Is No Better Than Tin 
 Plate as a Roofing Material 
 
 The unusual and interesting corrosion of the roofing material of 
 the Library of Congress was recently investigated. This building 
 has been covered since about 1893 by tinned sheet copper that has 
 become covered within the last 10 or 15 years with small pits; in 
 many cases, these pits have extended completely through the 
 sheet. Such a condition is interesting, particularly in view of the 
 fact that Washington is uncommonly free from smoke, which is 
 ordinarily understood to be a strong accelerating factor in corrosion. 
 The investigation has shown that the corrosion was due to no 
 accidental inferiority of the material, but that it is to be considered 
 as characteristic of all material of this type. It appears, therefore, 
 that tinned copper is not superior in any way to tin plate for 
 roofing material and that in view of its greater cost can no longer 
 compete with it. 
 
 Tinned sheet copper is used also for containing vessels such as 
 milk cans and for fittings such as troughs, etc., for soda fountains 
 
Laboratory Work 137 
 
 and breweries. It is probable that such articles would also be sub- 
 ject to pitting corrosion of the same type if they were not worn 
 out by actual abrasion before the corrosion had proceeded far. 
 
 To Prevent Volume-Change of Wood 
 
 Pieces of air-dried wood were treated in a variety of ways to 
 determine the best methods of retarding their absorption of moisture 
 from the air and loss of moisture when placed in dry air. Specimens 
 were treated with paraffin, impregnated with sugar, heated at high 
 temperature, painted, varnished, coated with bakelite, impregnated 
 with creosote, etc. Curves have been drawn showing the relative 
 shrinkage and swelling which took place in these boards when 
 exposed over a period of a year to atmosphere containing various 
 humidities. The most effective results were secured by coating the 
 wood with paraffin. Excellent results were also obtained from high 
 temperature treatments and by impregnating the wood with sugar. 
 
 Recent Pressure Tests of Welded Joints 
 
 Tests recently made in the machine-construction laboratory of 
 the University of Kansas show that the joints made by the 
 oxyacetylene method develop average strengths against rupture from 
 internal pressure as great as, if not greater than, those which may 
 
 TESTS SHOW SUPERIORITY OF WELDED CONNECTIONS 
 
 Size Pressure, Lb. per Sq.In. 
 
 Pipe Type Joint At Failure Maximum Nature of Failure 
 
 2 in. Welded T 4400 4400 Tube seam split 
 
 Welded T 2200 2200 Leak in tube seam 
 
 Welded T 4750 4750 Tube seam split 
 
 Screwed T 2350 2750 Sand holes in fitting 
 
 Screwed T 500 2000 Sand holes in fitting 
 
 3 in. Butt weld 5300 
 
 Butt weld 4950 4950 Tube seam split 
 
 Butt weld 4250 
 
 Coupling 3950 3950 Coupling split 
 
 Coupling 3400 4400 Leak In coupling 
 
 Welded T 3500 
 
 Welded T 4250 
 
 Welded T 3505 
 
 Screwed T 350 2700 Sand holes in fitting 
 
 Screwed T 300 3100 Sand holes in fitting 
 
 4 in. Butt weld 5100 Pipe bulged 
 
 Butt weld 3250 
 
 Coupling 300 3000 Leak at threads 
 
 Coupling 750 2600 Leak at threads 
 
 Welded T 3850 5100 Leak in weld 
 
 Screwed T 1000 1950 Sand hole in fitting 
 
 be ordinarily expected from screwed pipe connections. The data 
 given in the accompanying table are supplementary, but confirm- 
 atory of similar figures determined about a year ago. 
 
138 
 
 The Engineer in Field and Office 
 
 The results indicate that the strength of a welded pipe connection 
 is practically the same as that of unwelded pipe; and although care- 
 less welding might result in a leaky connection, if the line be tested 
 when installed it should be immune from trouble in service. 
 
 Special Pump Carries Pressure Over 5000 Pounds 
 
 A special high-pressure pump of simple detail was designed and 
 built for this work. It was connected to the specimens under test 
 by means of a i-in. copper tube. A pressure gage, with a check 
 valve opening toward the gage, was located on the tube the valve 
 being necessary to steady the pressure in order that satisfactory 
 readings could be obtained, because some of the samples carry pres- 
 sures greater than 5000 Ib. per sq.in. before failure. 
 
 Dense Wood Gives Nails High Values 
 
 Tests of the efficiency of various types of wooden joints were 
 made, and about 3000 nail-pulling tests were completed on nails 
 driven into twenty-five different species of American timber. While 
 the data have not been fully analyzed, it appears that the holding 
 power of nails has a definite relationship to the density of the 
 wood, and that there is practically no difference in strength between 
 a solid beam and a wooden beam of the same dimensions made of 
 two planks nailed together. 
 
Surveying 
 
 139 
 
 Practical Hints for the Surveyor 
 
 Small Motor Cars on Precise Level Work 
 
 Motor driven cars with flanged wheels for use on railroad tracks 
 carry the outfit used by the United States Coast and Geodetic Survey 
 in that part of their work which is upon railroad rights of way. 
 
 An interesting novelty is the adding machine attached to one 
 of the cars for recording the reports of the parties engaged in 
 precise leveling. A rigid frame, which holds the calculating device, 
 is bolted to the body of the car. The operator is provided with a 
 comfortable cushioned seat over the wheel, where he can do his 
 work conveniently. The added reliability and greater speed of the 
 machine for noting the readings of the level rods makes it a valuable 
 addition to the equipment of parties in the field. 
 
 Another car carries the level, the tripod being securely mounted 
 upon the frame of the motor vehicle, and the operator standing 
 
 Coast and Geodetic Survey Party Carried on Light Motor Cars 
 
 in the space between the tracks. Flat trays, or hand barrows, on 
 each car are available for transporting the other instruments, tools 
 and personal belongings of the party. 
 
 The cars are light in weight, with frames formed of steel tub- 
 ing, and are capable of traveling at a good speed with their load 
 of instruments and passengers. A small gas engine under the 
 frame supplies the motive power, and enables the party to reach its 
 field of operations promptly and without fatigue. 
 
140 The Engineer in Field and Office 
 
 Scale on Transit Leg Fixes H. I. 
 
 An easy method of establishing the height of instrument of a 
 transit where this is needed, as in stadia surveys, is to fix a scale 
 on one of the tripod legs by which the length of plumb-bob string 
 and hence the H. I. may be gaged. The procedure of placing and 
 using the scale is as follows: 
 
 Set up the transit over the hub and measure the H. I. carefully 
 and accurately. Have the point of the plumb-bob just touch the tack 
 or wherever the H. I. is measured from. Swing the point of the 
 bob to one of the legs of the transit and mark this point on the 
 transit leg. By similar markings scratch a scale on the transit leg, 
 using feet and tenths. Then at any time, with the point of the 
 bob touching the tack at any set-up, the H. I. may be read directly 
 on the leg of the transit by swinging the bob in an arc and reading 
 the point of the bob. This will give results to the nearest hundredth, 
 which is generally close enough. 
 
 Set Slope Stakes a Foot Outside 
 
 A deviation from the usual manner of setting slope stakes for 
 railroad grading has been used successfully by the writer. Instead 
 of the stake being driven slanting at the toe of the embankment 
 or top of the cut, it is moved out one foot farther and driven down 
 straight. Thus, each center-line stake is practically referenced by 
 two hubs, which are much less likely to be displaced than if set 
 at the edge of the slope. If the contractor is advised of the method 
 of setting the stakes, it has proved easy and convenient for him 
 to make his measurements accordingly. 
 
 Survey Data Made Available for Field Use 
 
 The engineer engaged in land surveying is often handicapped 
 in the field by finding that he has not secured enough notes to 
 cover the work to be done or by finding corners described by the 
 notes at hand destroyed, together with the witness trees, and that 
 a starting point some distance away must be sought. Again, the 
 surveyor will often find other bearing trees than those described 
 in the Government records; and unless he has the notes for these 
 trees, they are worthless. 
 
 First copies of complete section notes, giving all topography, 
 are secured for each township in which work is likely to be done. 
 By having the topography, a tedious search for a corner is often 
 done away with, as a reference measurement can be made from 
 
Surveying 
 
 141 
 
 some stream or ridge. These section notes are written on specially 
 printed blanks, each 8 x 11 in. and ruled as shown. After being 
 copied, all sheets are carefully checked. 
 
 To describe corners reestablished or reset, typewritten blanks 
 are prepared for section, quarter-section and donation-land claim 
 corners. These are filled out whenever the surveyor, or his assist- 
 ants, resets or establishes a corner. 
 
 
 South Bndr 
 
 5HEET | 
 # tbt,,* .C, 35 Z 
 
 
 
 Tu>p. 26 S R 5 w. 
 
 
 rt-69' 47' W 
 
 Between Section 35 "<* Srrtion 2. 
 
 
 2.OO 
 
 
 
 7 80 . 
 
 Va r 1-4' E" . 
 
 
 ZO 1 
 
 Ravine-. C. S. 
 
 
 31.00 
 
 Top of nd<5e. N Sc S 
 
 
 
 
 
 
 
 
 40. OO 
 
 Sri Quarter Post from wbicb a 
 
 
 
 Ye 1. Oak. 24" on. Bean. M.48*W. 132 IKs. 
 
 
 
 W. Ook 18" Di,.BeBr..5.8r^. 487 ttfs 
 
 
 
 
 
 
 
 
 57-00 
 
 Top o?- n'd(5e. Be'^n 4^ cfescend. 
 
 
 63.00 
 
 L?ove Oak opemo<fs, enfer pnairi>. 
 
 
 75.00 
 
 Ivfove hillj ^nfer voll^u. 
 
 
 76.2.0 
 
 Trail M. ^ S 
 
 
 
 
 
 
 
 
 80.00 
 
 Sel Post Corner to Sections 2-3-34-35 from which a 
 
 
 
 W.CbK. /<>" Dia. Bear,. S2S# . ?ff //ft . 
 
 
 
 <?}(,. 3" Dia. Bear*.5ff/f'f. 6f Hfi 
 
 
 
 ft. Offt S2. ' Di. Bean. f*Sf '& /44 /*-*. 
 
 
 
 tf. Oaf- " Dia. Bear*. H54'. 73 fr$. 
 
 
 
 
 Printed Form for Section Survey Notes 
 
 From the county surveyor's records a copy is made of any 
 descriptions of corners established. This search of records is kept 
 uptodate, and the data are transferred to the township portfolio as 
 soon as recorded. All reset corner sheets are filed according to 
 township and range. 
 
 Copies of all of the donation-land claim notes for each township 
 are secured, and these are bound along with the section and other 
 notes in the same portfolio. 
 
 Whenever a section or a claim is subdivided, a record is made 
 on a sheet giving character of corners and all courses and distances. 
 
142 The Engineer in Field and Office 
 
 This gives the surveyor working in that township a ready reference 
 to the work already done and many times saves a great deal of 
 work that might be a duplicate of some already surveyed. 
 
 The newspapers are watched; and whenever descriptions are 
 published for Torrens registration work, or other land descriptions 
 are given, they are clipped out and pasted to blank sheets and filed 
 in the proper township portfolio. 
 
 All of the above data for a township are bound in covers made 
 of heavy drawing paper cut to a size 9 x 12 in. and with a back 1 in. 
 in width. On this cover, at the top, are printed in large letters 
 the township and range numbers. 
 
 In practically all of the Western States, small lithographs of 
 each township, about 6 in. square, can be obtained, and one for the 
 proper township and range is cut down to a minimum size and 
 pasted on the portfolio cover below the title. This plat shows the 
 streams, sections and donation-land claims and acts as a key map 
 for the surveyor. 
 
 To facilitate the work of securing a meridian, either by means 
 of a solar instrument or by a direct observation, the latitude of 
 each tier of sections in the township is figured and written on the 
 right-hand side of the cover map, each latitude opposite the section 
 line for which it was computed. The longitude for the nearest 10' 
 is also shown in its correct position on the plat. 
 
 A portfolio of the size described can be easily folded in the 
 middle and held with two rubber bands, so as to be carried in the 
 surveyor's pocket. 
 
 By having with him the portfolio of notes for the township in 
 which he is called to work, the surveyor has as complete a record 
 as it is possible to have to enable him to reset or establish corners. 
 He also has other data of work done that will be of great value. 
 With these notes he can go from one job to another in the same 
 township without first having to send or go to the office for further 
 notes. 
 
 If surveyors in the same locality could be induced to exchange 
 notes of surveys, all data on reset corners or subdivision work could 
 be kept up to date, and each one would have the data in shape for 
 field reference. 
 
 Field Repair for Broken Steel Tape 
 From time to time there appear in the engineering magazines, 
 methods of repairing a steel tape in the field. Most of them will 
 slip without entirely pulling apart and are a constant source of 
 worry. The method outlined below is guaranteed not to slip. 
 
Surveying 143 
 
 Heat each of the broken ends with a match, drawing the temper 
 for about a quarter of an inch, so that it will bend without breaking. 
 Slip the end between the blades of your knife and bend to a right 
 angle. Then proceed to mend it by splitting a small stick and 
 
 Ends &f 
 Tape berrf- 
 
 This Repair Makes Slipping Impossible 
 
 making notches in one half to take the bent ends. Wrap with 
 a piece of twine after tapering the ends of the stick so that it 
 will not catch in the brush. Then proceed to chain and don't 
 worry as to whether your tape has stretched half an inch at the 
 splice. 
 
 Wedge-Shaped Stake Better than Straight Stake 
 
 Contractors are sometimes put to a great deal of inconvenience 
 and are forced to lose time and make mistakes by the engineer's 
 stakes being lost or displaced. The ordinary stake as used by the 
 engineer is so made as to be very easily knocked out of position. 
 This defect is due to the way in which the stake is sharpened. 
 
 The left-hand sketch gives the form of stake ordinarily used 
 a straight stick sharpened with a short slope from both sides. When 
 such a stake is driven, the point is the only part firmly seated, while 
 the body of the stake is as large just above the point as the rest of 
 the way up, so that the stake just stands in a hole made by the point. 
 This shape accounts for the ease with which most stakes are dis- 
 placed. However, if the stake be made of the form shown at the 
 right, it will be found to give much greater satisfaction. This stake 
 is sharpened only on one side, but the slope extends three-fourths 
 the length of the stake. When driven into the earth, the stake is 
 held very much more firmly than is the other kind, because the taper 
 is much longer and therefore the earth adheres to a greater length 
 of the stake. It is very difficult to draw this type of stake out of 
 the earth when once driven in. If exposed to traffic, as in the case 
 
144 The Engineer in Field and Office 
 
 of streets and highways, the stakes are sometimes broken off at the 
 ground, the stake breaking before it pulls up. In this case the point 
 is still in position and can be found and replaced. 
 
 V 
 
 Wrong and Right Way 
 
 A test of these two types of stakes was made on a highway on 
 which the traffic was very heavy. The following was the result: 
 Equal numbers of the two kinds of stakes being used, under equal 
 exposure, 14% of the first type were entirely lost, while only 2i% 
 of the other were lost. 
 
 Setting Grade Stakes for Bridge Approach 
 
 In grading and repaving the curved and raised approaches to the 
 Cambria St. bridge, Philadelphia, the street surface and curb and 
 gutter heights were first worked out by the help of a contour plan 
 drawn to a scale of 4 in. to the foot, with 0.1-ft. contours. To trans- 
 fer the final design to the ground the method adopted was laying out 
 a system of points on 10-ft. squares, finding the grades of these 
 points by interpolating between contours, and setting and marking 
 stakes accordingly. The labor of setting these stakes was not great, 
 and the resulting pavement surface corresponded more nearly to the 
 predetermined one than could have been obtained by the eye or by 
 the use of level boards. 
 
 Brass Tack in Lead Wool as Instrument Point 
 
 Contractors* engineers are often obliged to set points on finished 
 concrete in giving lines and grades for construction work. Chalk 
 and pencil marks are soon obliterated, chisel cuts are hard to find 
 or easily chipped and rendered indistinct unless the concrete has 
 thoroughly hardened, and in some cases cannot be used because they 
 would constitute a permanent defacement. A brass tack, on the 
 other hand, always stays bright even if set in a floor, and is easily 
 seen. 
 
Draftsmen's Kinks 145 
 
 The method which the writer has found convenient for setting 
 such tacks is to drill, preferably when the concrete is one or two days 
 old, a small hole an inch or more into the surface. This hole is then 
 packed full of lead wool, into which a large brass tack with a small 
 head is driven. Such points may, of course, be used either as transit 
 points or as benchmarks in horizontal or vertical surfaces. 
 
 Draftsmen's Kinks 
 
 Mounting Blueprints on Muslin 
 
 Maps and plans on paper frequently fail by tearing or wearing 
 through due to hard usage. Sensitized cloth has been employed more 
 or less successfully, but it has its disadvantages, due to the fact 
 that the cloth is generally of poor quality and tears easily. Further- 
 more, if allowed to stand for some time before being used, the sensi- 
 tizing solution causes the cloth to rot. A much better and not too 
 difficult method is to mount the paper print upon cloth. Large wall 
 maps hang better and are much less liable to be harmed when 
 mounted in this way than when left unmounted. 
 
 The print should be made upon "medium" weight paper unless an 
 extra-strong sheet is desired. While the printing is going on, a 
 helper can prepare the cloth backing. Unbleached muslin that sells 
 at about lOc. per yard is ordinarily used. Select a smooth board, 
 larger than the size of the print to be mounted, and clean it thor- 
 oughly. A drafting board or the top of a drafting table is excel- 
 lent for this purpose provided it is not cedar, for cedar will stain 
 the prints. Fasten the cloth on this board with 4-oz. carpet tacks 
 spaced about 2 in. apart, and driven only partially home so that they 
 may be easily pulled. 
 
 Tack one edge of the cloth down, stretching it smooth but not too 
 tightly, for the paper contracts on drying-out and will crack if there 
 is not enough "give" to the cloth. Follow around the edge of the 
 cloth until it is completely tacked down. It should now present a 
 smooth surface and is ready for the mount. If many prints are to be 
 mounted, it may be an advantage to set several boards, end to end, 
 and tack the cloth over their entire length. In this manner consid- 
 erable cloth can be saved. 
 
 After washing the prints they should be taken from the final 
 bath and the excess water blotted from both sides with a dry towel 
 or cloth. If the print has been made some time previously and is 
 dry, immerse it in water for two or three minutes or until it is 
 thoroughly wet then remove it and proceed as above. Lay the 
 
146 The Engineer in Field and Office 
 
 print carefully down on a clean table top or board and apply a thin 
 but even coating of paste, making sure that the edges and corners 
 have received their share. The paste should be a fresh, stiff corn- 
 starch paste or fresh wall-paper paste. Glue or library paste is 
 unsatisfactory and should not be used. 
 
 Pick the paper up carefully and while one man holds an edge 
 above the cloth, the other, on the opposite side of the table, should 
 take the lowered edge and paste it down using a stiff kalsomine or 
 large, flat paint brush. Brush the paper down, working away from 
 the body with short strokes, the helper slowly lowering his end. 
 In this manner the brush will drive out all air bubbles and make a 
 uniformly smooth job. After the paper is brushed fast, take a stiff 
 clothes brush and gently pat the edges down, thus insuring a perfect 
 contact at the vulnerable point. 
 
 The print should dry slowly in an even, moderate temperature 
 for at least 36 hours. The print can then be trimmed. If a Van 
 Dyke print, corrections, if any, should be applied at this time, using 
 ordinary black drawing ink. 
 
 Ruling with Common Ink Saves Time 
 
 In making scale sketches on desk designing sheets for direct trac- 
 ing by the draftsman, one engineer finds it a great convenience to 
 use ordinary, in place of india, ink. This requires a german-silver 
 ruling-pen, such as is made for bookkeepers' use. A time saving 
 results from the fact that when the pen is laid aside with its ink 
 filling it will not dry out, but will be ready for instant use even after 
 a quarter or half an hour. 
 
 Drawing the sketches in ink, rather than pencil, is far easier 
 for the tracer as well as being safer against errors in tracing. The 
 method applies to a great many parts or objects of such simple 
 character (or to be shown so generally) that no fuller detailing is 
 needed than the designer's sketch contains. However, lines as fine as 
 may be desired may be drawn. 
 
 Reducing the Cost of Plotting Stadia Notes 
 
 By plotting stadia notes on separate sheets such as are shown 
 in the accompanying sketch and tracing the finished map from these 
 sheets, the cost of plotting stadia notes has been materially reduced 
 and the speed almost doubled. Plotting topography by this method 
 becomes independent of drafting-room equipments, a lead pencil 
 being the only tool required. 
 
Draftsmen's Kinks 
 
 147 
 
 The ordinary method of procedure is to sketch the topography in 
 heavy pencil lines and either paste the sheets together for the drafts- 
 man or send them to him separately. The sheets are placed under 
 the tracing cloth, and the finished tracing is made directly from 
 them. The paper used for ordinary work is 84 x 11 in. in size. 
 
 '-& 
 
 Speeds Up Interpolation Increases Accuracy 
 
 Using a scale of 100 ft. to the inch, a length of 1000 ft. and a width 
 of 600 ft. of topography may be plotted on each sheet. Topography 
 may be plotted by surveyors on rainy days, either in the field or in 
 the office, several men working independently on separate parts of 
 the notes. It is remarkable how much the use of a graduated paper 
 speeds up the interpolation of contours and increases the accuracy 
 of scaling. 
 
148 
 
 The Engineer in Field and Office 
 
 Folding Drawing Trestle 
 
 A drawing-table trestle which will take up a space only 4 in. 
 square and 4 ft. long when stored, would prove a great convenience 
 to many engineers who do not need a drawing table continually, 
 or whose work sometimes requires one where ordinarily there would 
 
 Notches receive 
 Top cf Legs 
 
 Tire 
 Bon- 
 
 Adjustment for Height and Slope of Board Easily Made 
 
 not be proper facilities. The construction illustrated in the accom- 
 panying drawing has been used for the past two years and has 
 proven to be convenient, rigid, light and capable of being easily 
 transported and stored in a small space. 
 
 The following is a bill of necessary materials: 
 2 I x H-in. hardwood strips, 4 ft. 1 in. long, front legs. 
 2 f x H-in. hardwood strips, 3 ft. 10 in. long, back legs. 
 1 I x 4-in. hardwood board, 34 in. long, top piece. 
 6 1-in. shothead screws. 
 2 2-in. tire-bolts and washers. 
 1 2i-in. tire-bolt and washer. 
 
 1 f-jn. band-iron strip, 7 in. long, drilled for screws on 6-in. cen- 
 ters and one hole cut out to serve as a hook. 
 
Draftsmen's Kinks 149 
 
 1 I-in. band-iron strip, 4 in. long, drilled for screws on 3i-in. 
 
 centers. 
 
 The method of assembling is perhaps sufficiently illustrated in 
 the drawing. By placing the top ends of the longer legs in the dif- 
 ferent notches, which must be gained in the top piece, the top of 
 the trestle can be made either level or sloping, and the height ad- 
 justed from 34 in. to 42 in. 
 
 How To Waterproof Drawings 
 
 A. Give the drawing several light coats of white shellac, dis- 
 solved in grain alcohol, letting each coat dry before the next is 
 applied. Orange shellac and even wood alcohol may be used; but 
 the "white" or bleached shellac is preferable and wood alcohol is 
 objectionable because of its injurious effect on the eyes. 
 
 B. Give the drawings several light coats of "Zapan" varnish, 
 which is made of scrap trimmings of clear sheet celluloid dissolved 
 in acetone and is produced by several Eastern chemical factories 
 and firms manufacturing celluloid articles. 
 
 C. When a heavier protective covering is desired than A or B 
 will provide, the drawing may be made wet with the thin celluloid 
 varnish and pressed down evenly on a sheet of thin sheet celluloid, 
 then allowed to dry. This process gives a beautiful clear mounting 
 with 0.01 in. of celluloid on the face. 
 
 D. Drawings may be made waterproof with melted paraffin wax, 
 which is applied with a flat bristle brush. The drawing is then put 
 between two sheets of blotting paper, and a hot sad-iron is passed 
 over the upper blotter, thus causing the paraffin to be distributed 
 more evenly and the surplus to be absorbed by the blotting paper. 
 The blotters must be removed before they cool. If the wax is thick 
 and white over any part of the drawing or print, sponge it off with 
 benzine. 
 
 E. Drawings may be paraffined by dissolving the paraffin wax 
 in benzine and then thoroughly painting the drawing with this 
 liquid or passing the drawing through a bath and hanging it up to 
 dry. 
 
 Some of the solvents mentioned are very inflammable and even 
 explosive, so all open lights should be kept away from them. Some- 
 times they affect certain people injuriously; accordingly, such work 
 should be done only in a well-ventilated room, with a fan to keep 
 fresh air moving over the work. 
 
150 
 
 The Engineer in Field and Office 
 
 Make This to Carry Your Drawings 
 
 It is customary for drafting rooms to place their drawings, 
 either every night or once a week, in a vault for safe keeping. The 
 device shown in the illustration has proved satisfactory for carrying 
 the drawings. It is easy to make, two pieces of white pine A, 
 37 x 11 x I in., two black japanned door pulls B and one piece of un- 
 bleached cloth C, 37 x 30 in., being fastened together in the manner 
 
 A Convenience and Takes Up No Room 
 
 shown. If desired, a small hook and eye may be attached at each end 
 of the wood crosspieces to hold them together and prevent the loss 
 of drawings when the carry-all is laid down. 
 
 Plot Offsets with Frame and Sliding Piece 
 
 A device for mapping survey notes, consisting of a fixed frame 
 for longitudinal measurements and a sliding scale for offset dis- 
 tances, is shown in the accompanying sketch. The rectangular 
 frame is made of 1-in. sheet iron. The scale along the left-hand edge 
 can be stamped on or glued on. The sliding scale can be readily 
 made from an old celluloid triangle. To orient the scales, the center 
 point at the top of the hollow rectangle, which is opposite the zero 
 of the longitudinal scale, is set over one transit point and the zero 
 of the sliding scale over the other. The edge of the sliding scale 
 will then always be at right angles to the base line. 
 
Draftsmen's Kinks 
 
 151 
 
 It may be seen that any survey made by pluses and right-angle 
 offsets from a base line, such as railroad station-map surveys, can 
 be readily plotted with the device. It might be convenient to provide 
 
 Pluses and Offsets Easily Plotted by This Device 
 
 four scales by starting one from each of the four corners of the 
 steel frame, and making two sliding pieces with a scale on each face. 
 Both a 50-ft. and a 100-ffc. scale would be used frequently. 
 
 Keeping Tab on Revised Drawings 
 
 In supervising a large concrete building job at some distance 
 from the main office where the detail plans are made, there is ever 
 present a danger that the latest plans may not be used by the field 
 superintendent and the construction gang. The structural plans for 
 a concrete building are seldom completed when bids are called for, 
 the usual practice being to have the footing design and column 
 schedule completed at the time so that the material can be ordered 
 and work started without delay after awarding the contract. The 
 detailing of the superstructure is usually carried on slightly ahead 
 of the construction work, necessitating the issuance of several pro- 
 gress prints of the same plan. 
 
152 
 
 The Engineer in Field and Office 
 
 It has been found worth while to issue a memorandum at the end 
 of each week, giving the date of the latest print of each plan issued. 
 These memo's are typewritten on standard specification-size sheets. 
 Blueprints are made from them and are sent to the superintendent 
 and contractors, who post them in the various field and main offices. 
 Blueprints are used since they are more conspicuous and more apt 
 to be regarded as a part of the plans than are carbon copies. The 
 following form is used : 
 
 PLAN MEMORANDUM 
 
 Date 
 
 Building for "A. B. Co." City 
 
 Post in a Conspicuous Place. 
 
 The latest prints of plans to be used are dated (with rubber stamp) as 
 follows : 
 
 Sheet No Description Date 
 
 These memoranda are sent out on Saturday of each week, except 
 when only one or two revised prints have been sent out since the 
 last memorandum. 
 
 Each time a sheet is revised or some new feature is added, a note 
 (with date made) is placed on the tracing in a space provided in 
 the title of the sheet. In addition to this each print is marked with 
 rubber stamps, as shown herewith. 
 
 The upper stamp calls attention to the fact that the print con- 
 tains some revision or addition not shown on previous prints, and 
 by referring to the revision list (in title) the extent of the change 
 
 REVISED PRINT 
 
 Destroy all prints 
 
 previously sent you 
 
 THIS PRINT MADE 
 
 Dec. 20 1917 
 
 Prints Marked ivlth These Two Stamps 
 Upper stamp is 3| x 1 in. ; lower is 2J x g in. 
 
 can be found at once. If the print bears a later date than the one 
 noted for this sheet on the memorandum sheet posted in the field 
 office, the memo is revised by the superintendent to show the date 
 of the latest print. In this way a careful record of the latest prints 
 is kept, and anyone not familiar with all the details of the work can 
 
Filing Data 153 
 
 quickly find, by referring to the memorandum sheet, which prints 
 should be used for construction work, and thus costly errors due 
 to use of superseded and void plans are avoided. 
 
 Simple and Effective Methods for Filing 
 Engineering Data 
 
 Lantern Slides Should Be Indexed and Filed 
 
 Perhaps the most customary method of filing lantern slides is in 
 the wooden boxes which are on the market for that purpose. These 
 are of varying capacities, containing from 50 to 200 slides. Each 
 slide has its individual compartment formed by cardboard parti- 
 tions inserted in grooves in the sides of the box. When the hinged 
 cover is raised the rim of the long way of the box is seen to be 
 divided off by the indentations made by the grooves. Each division 
 marks a slide compartment, and it is convenient to number these di- 
 visions on the front rim with small india-ink figures to correspond 
 with the numbers of the slides. On either end of the exterior of the 
 box the inclusive numbers should be indicated. As the slides are 
 numbered in the order of their accession no duplication occurs, and 
 the boxes may be arranged uniformly and neatly in numerical 
 sequence. 
 
 Each slide when received is numbered in india ink upon the 
 thumbspot. An indelible ink is especially necessary for this since 
 the thumbspot marks the position for the operator's thumb when 
 he inserts the slide in the lantern, and ordinary ink would smut. 
 Close beside the thumbspot there should be another small sticker 
 which is left blank so that those slides selected for a lecture may be 
 lightly numbered in pencil to insure their temporary sequence. On 
 a narrow strip pasted across one end of the slide the brief title 
 should be written. 
 
 To avoid misplaced slides they should be arranged so that they 
 face the left-hand end of the box and have the thumbspots at the 
 top, thus facilitating ready detection of any discrepancy between 
 a slide number and that of its compartment. Similarly, in the trav- 
 eling case, this arrangement is a convenience since it enables the 
 operator to seize the slide with its face toward him and by a turn 
 of the wrist to invert it in readiness for insertion in the lantern. 
 
 As received the slides are listed under the headings Slide Num- 
 ber, Title, Owner, Date and Origin, on lettersize sheets secured be- 
 tween cardboard covers by brass binding pins. Following this ac- 
 cession list and separated from it by a colored sheet is the place or 
 
154 
 
 The Engineer in Field and Office 
 
 subject list. To each place of which there are descriptive slides 
 a page is devoted upon which the numbers and titles are listed. 
 For theoretical features, diagrams, tabulations, etc., a sheet headed 
 Miscellaneous is provided, from which, however, any of the items 
 may be segregated upon separate subject sheets when desirable. 
 These place and subject sheets are assembled in alphabetical se- 
 quence. 
 
 A heavy manila envelope, say 9x5 in., pasted on the inside of 
 the back cover, affords an opportunity for the filing of lists of slides 
 temporarily withdrawn from the file. While these lists may be mere 
 memoranda to be destroyed when the slides have been checked off 
 as returned, it is preferable to typewrite them in permanent form 
 upon sheets headed with the name of the borrower, the title of the 
 talk, the place, date, etc. since such lists have a suggestive value 
 in the preparation of further illustrated talks. Before the slides are 
 returned to their compartments the pencil numbers added by the 
 borrower should be transferred to the loan list, to show the sequence 
 in which the slides were used, and then erased from the slides. 
 
 Blueprint Table has Several Functions 
 
 The table shown in the sketch combines the functions of the 
 storage can, the scissors and the yardstick. The roll of paper is 
 
 puffing Edge 
 
 _gi 
 
 
 r 
 k 
 
 i 
 
 ==a=- 
 
 ^T^^--^--^^ 
 
 i 
 
 o 
 
 r 
 
 -Slot -for Paper 
 
 ^L-j^, *L t/ ff^tlSJ** 
 
 
 Blueprint Table Saves Time and Paper 
 
 stored in -the box at the end and pulled out through the slot, meas- 
 ured with the foot marks and torn off on the cutting edge. Less 
 
Filing Data 155 
 
 than i in. of paper is spoiled, and this only when the strip is left 
 exposed for a considerable length of time. At least this much is 
 ordinarily wasted by excess cutting. The left-hand box is used for 
 odd sheets of paper, but may be slotted and used for a different 
 grade of paper. 
 
 Pamphlets Indexed and Filed by Simple System 
 
 Pamphlets in great variety, principally bulletins and reports, are 
 available in constantly increasing number and comprise a very im- 
 portant class of current literature. The value of the information 
 which they contain is, however, considerably lessened if they are 
 not indexed and filed in a manner which facilitates easy reference to 
 their contents. Indexing and filing pamphlets by the following plan 
 has been found to be a simple matter and to give satisfactory results 
 as to convenience of reference. 
 
 As soon as convenient after receiving, the pamphlet is read, or at 
 least inspected to ascertain the character and scope of its contents. 
 As this is being done such index cards as are thought desirable are 
 written. For this purpose a very thin 3-in. x 5-in. card ruled hori- 
 zontally and made up in pads is used. For this and general 
 notebook purposes it is convenient to carry a number of these cards 
 in a loose-leaf notebook. 
 
 The index cards are then placed together in the pamphlet until it 
 proves convenient to assign serial numbers to the pamphlets for 
 filing purposes. A simple record of the pamphlet numbers assigned 
 is kept by filing with the pamphlets a 6-in. x 9-in. card on which 
 the last serial number assigned is noted each time. It has been 
 found most convenient to place the numbers on the upper right-hand 
 corner of the index cards and on the upper left-hand corner of the 
 pamphlet cover. This numbering may be done by hand, though a 
 numbering machine does the work more neatly and quickly. A very 
 satisfactory substitute is a rubberstamp numberer, similar in con- 
 struction to the familiar band dater. 
 
 The pamphlets are then filed in the order of their serial numbers 
 from left to right on shelves or in bookcases. A decidedly neater 
 appearance is given the collection when filed in pamphlet boxes. It 
 will be found a simple matter to make up these boxes as needed after 
 the construction indicated in the illustration. Where heavy card- 
 board is used, the bending is facilitated by making a very light 
 knife cut on the fold lines. A neat appearance, as well as a stronger 
 box, results when the exposed edges are bound with gummed cloth 
 tape or the gummed paper strips used in binding lantern slides. 
 
156 
 
 The Engineer in Field and Office 
 
 Each pamphlet box should carry a serial number as well as a number 
 corresponding to the highest serial number of the pamphlets that are 
 filed in the box. 
 
 / 
 
 ,-7 
 
 V 
 
 Cv 
 
 t , 
 
 / 
 
 1 
 
 X 
 
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 : 
 
 
 
 
 
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 k.- . - - /? ^ sj 
 
 lyp - 
 
 ."White pine 
 _ ^~ >-L_^_ ___ Binding-'''^" 
 
 "T" 
 
 Highest serial number of pamphlets filed in box - 
 
 Serial number of box --^ -^ 
 
 M 
 
 No. 19 Wire nails, j long, flat head-- .&.-:?< 
 Filing Box Is Easily Made 
 
 The filing of pamphlets by arbitrary serial numbers is far more 
 simple, elastic and generally satisfactory than any attempt to 
 classify or group these publications according to their subject 
 matter. And any system of indexing, to be satisfactory, demands 
 the personal attention of the person who is to make use of it, as the 
 average office help cannot be expected to do indexing of this sort 
 with any satisfactory degree of intelligence. 
 
Filing Data 157 
 
 Index of Details for a Structural Office 
 
 Well executed and consistent plans are the prime indication of a 
 good design in all classes of structures ; especially in building work, 
 which involves a great many different types for the great variety 
 of uses. This makes standardization of details and design somewhat 
 more difficult than for the superstructures of highway and railroad 
 bridges, but unless standardization is kept in mind constantly, the 
 cost of making the design is quite likely to be so high as to show 
 little profit; and at the same time the resulting structure may be 
 more costly to the owner than if the reverse were true. 
 
 A large structural-engineering office one employing a large 
 force of draftsmen and designers, and carrying on work simultane- 
 ously on several large buildings must of necessity have a good set 
 of office standards for the guidance of the men and as an aid to the 
 chief draftsman or engineer in obtaining uniform practice on all 
 jobs of the same type, without necessitating his spending the 
 greater part of his time giving instructions and personal supervision 
 to each and every man or squad. 
 
 The office standards for concrete building design should include 
 tables and diagrams for the design of reinforced-concrete slabs and 
 
 M \ 
 beams (such as values of K = TJZ ) f r various combinations of 
 
 unit stresses; areas and weights of steel bars; data on web rein- 
 forcement of beams; reinforcement of spandrel girders; diagrams 
 and tables for the design and detail of reinforced-concrete columns 
 and footings and for steel columns incased in concrete; tables and 
 details showing amount and method of reinforcing concrete stairs, 
 and standard sheets showing the arrangement of lettering, dimen- 
 sions, details, etc., on the floor plans. For steel building design the 
 standards may include properties of various types of columns ; con- 
 nection details; bracket details; cast-iron bases; typical details of 
 spandrel beams, crane girders, steel stairs, steel stacks, tank floors, 
 towers, etc. 
 
 In order that original and special details developed which would 
 not ordinarily be indexed in the general job file or included in the 
 standards may be readily found, a card index of various details 
 of completed designs in the office files, which are likely to be used 
 on other work or referred to at various times, should be maintained. 
 With such a file a new man in the organization can at once acquaint 
 himself with methods of detailing certain portions of a standard or 
 
158 The Engineer in Field and Office 
 
 special building without a lengthy explanation on the part of the 
 chief draftsman, thus saving much valuable time and increasing 
 materially the speed with which the plans can be completed. 
 
 Filing Catalogs and Pocket Maps 
 
 Some of the material to be filed in an engineering library, 
 particularly trade catalogs and folded pocket maps, is so diversified 
 in size and shape that it is hard to handle. Thus, while it has 
 come to be generally conceded that trade catalogs ought to be unified 
 as to dimensions, and while this would be of advantage not only to 
 the possible purchaser but also to the manufacturer, the catalogs 
 continue to vary from the flimsy leaflet to the substantially bound 
 volume. Yet, as the engineer uses them in making estimates of cost, 
 in selecting equipment, and in other ways, he must have them readily 
 available and well indexed. 
 
 The general indexing schedule in use in one library is a form of 
 the decimal system, by which the books and data are assembled under 
 various classifications according to subject matter. This modified 
 Dewey system was found to be too detailed for application to the 
 trade catalogs, and it was necessary to simplify it; that is, K 6, 
 Water Works Distribution System, including in its subdivisions the 
 subjects of pipes, valves, distributing reservoirs, conduits, meters, 
 etc., became in the simplified schedule, K 6, Water Works Pipes and 
 Valves; while K 6.5, Meters, became more comprehensive and 
 included Measuring Devices for Water. 
 
 Within each classification it was decided to maintain an alpha- 
 betical sequence of the catalogs according to the names of the firms 
 issuing them. To do this an exceedingly flexible filing device was 
 necessary, since it was planned to place the material without regard 
 to size and shape and without segregating the bound volumes. Pam- 
 phlet boxes would have meant considerable waste space, and vertical 
 files either the segregation of the bound volumes or an unwarranted 
 expenditure for filing units. Heavy manila envelopes were also 
 considered for the filing of the leaflets and pamphlets, but were 
 found undesirable both because they were incommodious, and be- 
 cause when the envelopes were stacked the exposed ends offered on 
 surface for indexing. 
 
 It was decided to use a pasteboard receptacle open at the top, 
 containing cardboard folders with tabs, such as are used for filing 
 correspondence. The containers come in two widths, 1 in. and li 
 in., and are 12 in. long just the depth of the open shelves upon 
 which the catalogs were to be stacked. The exposed end of the 
 
Filing Data 159 
 
 unifile is curved and is covered with heavy brown paper. Upon this 
 a sticker, bearing the classification number, was placed. Except in 
 those instances where a whole container was devoted to the catalogs 
 of a single firm, the indicating of the contents upon the end was 
 avoided, so that as new material was added the cardboard folders 
 could be shifted. On the tab at the top of each folder, however, the 
 name of the manufacturer and the classification number were placed, 
 while on the bound volumes and the thicker of the pamphlets strips 
 were pasted with the firm name. 
 
 In connection with this file a card index of the names of the 
 manufacturers was maintained, with the classification number, or 
 numbers, under which the catalogs of each firm were to be found. 
 It has proved extremely useful to include also in this index the trade 
 names of materials, since these so often differ from the name of the 
 manufacturer or of the firm issuing the catalog. As the catalogs are 
 assembled according to subject matter, a subject index has not been 
 found necessary, but reference to an advertising index is made when 
 doubt arises as to the manufacturer of some special material. This 
 method has been tried out for five years, in the filing of 16 shelves 
 of catalogs, and found satisfactory. 
 
 From the very fact that they are designed to be tucked away, the 
 pocket maps are likely to be tossed into a desk drawer or placed in 
 a pigeonhole and forgotten. It is wise, therefore, to have a file of 
 them in some conspicuous place where they will be readily accessible 
 and will not be overlooked. Like the trade catalogs the pocket maps 
 vary in size and shape, for while some seem designed for the coat or 
 outer pockets, very many are long and flexible and of a form suit 
 able for the vest or trousers pockets. A simple device for main- 
 taining a neat and uniform file of such maps is the heavy manila 
 envelope of standard size (4i in. by 10i in.) with its flap removed 
 and a cloth tape tab H in. in length pasted on the closed long edge. 
 On this tab the brief title of the map is written. The envelopes are 
 filed on end in alphabetical sequence of the titles of the maps. The 
 tabs are bent to one side and as they have been pasted at varying 
 intervals on the long side of the envelopes it seldom happens that 
 they overlap. If it should chance that a map is too long for an 
 envelope, the latter may be slit at the top end. This file is kept in 
 a glass-front case and stacked by means of tin rack ends. Rack ends 
 placed behind the envelopes will keep them from slipping back on 
 the shelf. In the general card catalog of material in the library, the 
 maps are listed under the subject "Maps" and also under the in- 
 dividual titles. 
 
160 
 
 The Engineer in Field and Office 
 
 Value of Carefully Kept Stadia Notes 
 It is especially important that some definite form of note-keeping 
 be followed in making stadia surveys, even if they are to be platted 
 by the one who makes the survey. There are so many classes of 
 information to be recorded, that if the work is not done systemati- 
 cally, the value of the data recorded is lost through the impossibility 
 of transferring the information contained in the notes to a scale 
 
 IP. 
 
 & 
 
 77? .as 
 
 Ufff 
 
 H.L 
 
 F.S. 
 
 Eleva. 
 
 f.1 
 
 3.25- 
 
 6-7 
 
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 SJ 
 
 33.3 
 
 37.' 
 
 37-W 
 
 36.Z 
 
 J7./ 
 
 tSW; 
 
 oMDlsf. 
 
 rrTr 
 
 J 6+33 
 
 ffem 
 
 Poad turns L 
 
 Field 
 
 onK 
 
 Hub in Rocrd 
 
 Lowsp&ZOOb. 
 
 Hub In Pocrd 
 
 arks 
 
 M.VM 
 
 Field 20 KcfZ 
 
 Ske 
 
 Systematic Note-Keeping Helped by This Form 
 
 map. This form must, of necessity, be adapted to the work to 
 be done, and should, so far as practicable, conform to established 
 forms of note-keeping. A form used in making drainage recon- 
 naissance surveys is illustrated by the accompanying sample of notes 
 which were recently taken in the field. 
 
 Turning points and instrument points are numbered successively 
 arabic figures being used for turning points, as they are usually 
 placed on the stake by an untrained assistant, and Roman numerals 
 for the instrument points. The turning points are available for 
 later cross-line surveys. All instrument heights and heights of turn- 
 ing points are calculated in the field as well as the stadia distance. A 
 mental calculation is made by adding one-half the observed distance 
 to the lower stadia reading as a check on the level reading on the 
 central cross-head. This also serves as a check on the observed 
 distance. "- 
 
Filing Data 161 
 
 In line surveys the distance from starting point to each instru- 
 ment point and turning point is computed and recorded in the dis- 
 tance column, this computation being done at night, or after return 
 to the office. After being checked by adding the observed distance 
 from starting point, the total distances are set down in ink and are 
 of assistance in platting the survey. 
 
 Location of Water Mains, Connections and Valves 
 Kept on Card File 
 
 Any card system of keeping records which has proven its value 
 by twenty years and more of continual use, without radical change, 
 is worthy of notice. In this class falls the card system for re- 
 cording the location of water mains, valves, connections, fire hy- 
 drants and other special fixtures, which is in use by the Water 
 Department of the City of St. Louis. This system comprises the 
 use of specially printed 4x6 cards kept in drawers and referred to 
 ordinarily only by members of the office force of the distribution 
 system. The accompanying illustration gives a very clear indication 
 of the nature of the card and the information kept on it. Each 
 size of pipe and each particular fitting has a special symbol, and the 
 situations of all valves are marked, showing their position with 
 reference to the curb or building line. 
 
 The street running from bottom to top is an east and west street, 
 and from left to right, a north and south street. The east and west 
 streets follow each other alphabetically in the drawers; that is to 
 say, Atlantic Ave. would come before West Ave., and all intersec- 
 tions with north and south streets are represented by succeeding 
 cards which start from the most easterly intersection of the east and 
 west street with a north and south street. Therefore, to locate any 
 intersection it is necessary only to know which of the streets is an 
 east and west street. 
 
 Each card is inclosed in an envelope of transparent paper, which 
 keeps it from being soiled by the rather excessive handling to which 
 cards of this sort are subjected. It is only possible to take the cards 
 from the drawer by unlocking a special keeper-rod, the kkey to which 
 is guarded carefully and is never allowed to leave the possession of 
 the chief draftsman of the water department. 
 
162 
 
 The Engineer in Field and Office 
 
 
 
 
 
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Filing Data 163 
 
 Filing Records in a City Engineer's Office 
 
 The filing of the city's engineering records in Los Angeles is 
 fully explained by George H. Tilton, Jr., of the City Engineer's 
 Office. The classification is as follows: 
 
 1. Records showing location are termed maps. 
 
 2. Records showing profiles are termed profiles. 
 
 3. Records showing detail are termed plans. 
 
 4. Fieldbooks, deeds, etc., are self-explanatory. 
 
 Mr. Tilton says: "The conglomeration of sizes is sorted into 
 lengths and a series of numbers is allotted to each length in 
 each classification, as follows:" 
 
 1 to 249 Roll maps 12 in. wide and under. 
 250 to 1.999 Roll maps 12 to 18 in. wide. 
 
 2,000 to 3,999 Roll maps 18 to 24 in. wide. 
 
 4,000 to 5,499 Roll maps 24 to 36 in. wide. 
 
 5,500 to 5,999 Roll maps over 36 in. wide. 
 
 6,000 to 9,999 Flat maps of a uniform size. 
 10,000 to 10.249 Roll profiles 12 in. wide and under. 
 10,250 to 10,999 Roll profiles to 18 in. wide. 
 11,000 to 14,999 Roll profiles 18 to 24 in. wide. 
 15,000 to 19,999 Flat profiles of a uniform size. 
 20,000 to 20,999 Roll plans 12 in. wide and under. 
 21,000 to 21,999 Roll plans 18 to 30 in. wide. 
 22,000 to 24,999 Roll plans 30 in. wide and over. 
 One up for fieldbooks, deedbooks, etc. 
 
 As soon as one of these series of numbers is exhautsed the 
 alphabetical prefix is assigned and the series re-run. 
 
 The actual indexing and numbering is now ready to be done 
 rapidly and accurately. Each record is numbered with a stamp 
 so that all numbering is of uniform size and in the same location 
 on the record. Each classification is listed in a "list book" and 
 indexed both in the "division index" and "alphabetical index" so 
 that it can be found either by name or location, one of which it is 
 necessary to know. In the division index the records are arranged 
 according to year made. 
 
 Sixteen years ago, when this system was inaugurated, the area 
 of the city was 43.26 sq.mi.; today it is 337.92 sq.mi. This 
 continued expansion has not impaired or confused the early records 
 in any way, in fact an early record is found as quickly as a late 
 one. To keep this system up to date and the records in place the 
 entries services of one man have been found necessary. 
 
 Large Number of Road Plans Filed in Simple Rack 
 
 The accompanying photograph shows the method of filing 
 blueprint road plans of a large number of townships. The scheme 
 consists merely of mounting the blueprints of each township between 
 
164 
 
 The Engineer in Field and Office 
 
 two stick or lath binders and hanging each pair of binders on an 
 inclined rack. The titles and numbers of the roads are printed 
 in black ink on one side of the binder sticks, and just enough 
 
 Rack Inclined to Show Titles 
 
 inclination is given the rack so that the titles of all the binders 
 are readable to one standing in front. Not only is convenience 
 served, but the cost of the rack is negligible. 
 
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. THE PENALTY 
 WILL INCREASE TO 5O CENTS ON THE FOURTH 
 DAY AND TO $1.OO ON THE SEVENTH DAY 
 OVERDUE. 
 
 
 CIRCULATION 
 
 LD 21-100m-7," 
 
YC I 05309 
 
 U.C. BERKELEY LIBRARIES 
 
 ^ - 
 
 UNIVERSITY OF CALIFORNIA LIBRARY