A TREATISE ON WOODEN TRESTLE BRIDGES ACCORDING TO THE PRESENT PRACTICE ON AMERICAN RAILROADS. BY WOLCOTT C FOSTER. OP UHXVSESIT7 NEW YORK: JOHN WILEY & SONS, 53 EAST TENTH STREET. 1891. COPYRIGHT, 1891, BY JOHN WILEY & SONS. ROBERT DBCMMOND, FERRIS BROS, Electrotype*, Printer* 114 & 146 Pearl Street, 826 Pearl Street, New York. New York. PREFACE. IN collecting the data for this work, a circular letter was sent to each chief engineer throughout the country of whom the author could obtain the address. These letters met with many hearty responses, and resulted in the collection of a very complete set of plans of the standard trestles in use on the different roads. Tables embodying the details of all the different parts were compiled, and the deductions made from these. Every effort has been put forth to make the work as valuable and com- plete as possible, without making it too bulky. Neither time, pains, nor expense have been spared in its preparation. As far as possible credit has been given in the body of the work to the originators of any special design ; but as oversights may have unintentionally occurred, a list of those engineers who have aided the author is appended. It is the earnest hope of the author that the results of his labors will prove worthy of the courtesy and aid so generously extended to him by the members of the profession at large, many of whom were perfect strangers. LIST OF THE ENGINEERS TO WHOM THE AUTHOR IS INDEBTED FOR AID IN PREPARING THIS WORK. Alger, Chas. E. Ansart, Felix. Bates, Onward. Becker, M. J. Berg, Walter G. Bissel, F. E. Blunt, Jno. E. Boiton, C. M. Booker, B. F. Bovven, A. L. Briggs, R. E. Buxton, C. Canfield, E. De Caradene, A. Curtis, F. S. Davery, R. A. Dick, H. B. Dorsey, W. H., Jr. Elliott, R. H. Fisher, J. B. Fitch, A. B. Fratt, F. W. Gore, Th. Greenleaf, J. L. Griggs, J. Hawks, J. D. Howe, W. B. W., Jr. Hoyt, Wm. E. Kennedy, H. A. Kriegshaber, V. H. Levings, Chas. Lum, D. W. Martin, M. A. McVean, J. J. Miller, N. D. Mills, A. L. Molesworth, A. N. Monroe, J. A. Montfort, R. Morton, T. L. Nelson, J. P. Nettleton, G. A. Nicholson, G. B. Patton, E. B. Perris, Fred. T. Reed, A. L. Rich, W. W. Riffle, F. Rowe, S. M. Sage, I. Y. Schenck, A. A. Smith, P. A. Spofford, Parker. Swift, A. J. Weeks, I. S. P. Wheeler, D. M. White, H. F. Whittemore, D. J. Woods, J. E. Zook F. K. CONTENTS. PART PAGE PREFACE, ... . ni TECHNICAL TERMS AND NAMES, . ix CHAPTER I. INTRODUCTION. Extent Necessity for wooden trestles Inspection Repair Economy Designing Keraning devices Fires and fire protection Classification, ..... .1 CHAPTER II. PILE-BENTS. When used Timber Qualities Arrangement of piles Lengthening of piles Shoeing piles Split- ting of piles Driving Construction records Cost Fastening to cap, . . .6 HAPTER III. PILE-DRIVERS. Mounted pile-drivers Steam pile-drivers Floating pile-drivers Track pile-drivers Steam hammers, . 13 CHAPTER IV. FRAMED BENTS. Foundations Sills Posts Caps Joints Spacing, 24 CHAPTER V. FLOOR SYSTEM. Corbels Stringers Ties Guard-rails Fastening down floor system, 31 CHAPTER VI. BRACING, COMPOUND-TIMBER TRESTLES, HIGH TRESTLES, TRESTLES ON CURVES, AND MISCELLANEOUS TRESTLES. Sway-bracing Counter-posts Longitudinal bracing Lateral bracing Compound-timber trestles High trestles Classification and description Longitudinal bracing Lateral bracing Trestles on curves Elevating the rail Double-track trestles Knee-braced trestles Round timber trestles Trestles with solid floors, 39 CHAPTER VII. IRON DETAILS. Cut spikes Boat-spikes Drift-bolts Dowels -- Bolts Lag- screws Separators Cast washers- Wrought washers Nut-locks -45 v vi CONTENTS. CHAPTER VIII. CONNECTION WITH THE KMHAXKMKNT AND PROTECTION AGAINST ACCIDENTS. Bank-sills Bank-bent Rerailing-guard Refuge-bays Foot-walks Water-tubs Iron-covered strin- gers Earth-covered floors 52 CHAPTER IX. FIELD-ENGINEERING AND ERECTION. Laying out in the field Erecting Tools employed in building 56 CHAPTER X. PRESERVATION AND STANDARD SPECIFICATIONS. Preservation of joints Standard specifications Form of proposal, 61 CHAPTER XI. BILLS OF MATERIAL, RECORDS AND MAINTENANCE. Bill of timber Bill of iron Aids to making out estimates Feet B. M. General bill of timber Con- struction records Masonry Timber estimate Division trestle estimate Inspection Track- walkers' report Inspection records Bridge instructions of the N. Y., L. E. & W. R. R. and the B., C. R. & N. R. R. Premiums for repair Repairs Tests Bridge numbers, . . . .70 PART II. SECTION I. PILE-TRESTLES. Plate I. Denver & Rio Grande Railroad 86, 87 II. Toledo, St. Louis & Kansas City Railroad 88,89 III. Atlantic & Pacific Railroad 9- 9 1 IV. Chicago & West Michigan Railway, 92, 93 V. Minneapolis & St. Louis Railway, 94. 95 VI. Chicago & Northwestern Railway, 96, 97 _X:|' I Louisville & Nashville Railroad, 9 8 > 99 IX. Boston & Albany Railroad, 100, 101 SECTION II. FRAMED TRESTLES. Plate X. Chicago & West Michigan Railway, 102, 103 XI. Pennsylvania Railroad 104, 105 XII ) Ji: \ San Francisco & North Pacific Railroad, 106,107 II 1 1. ' XIV. \ XV. V Norfolk & Western Railroad, io8toiii XVI. ? XVII. Louisville & Nashville Railroad, 112,113 XVIII. Oregon Pacific Railroad, 114,115 CONTENTS. vn XIX. Ohio Connecting Railway, . , XXI [ Charleston, Cincinnati & Chicago Railroad, 1 1810121 XXII. Minneapolis & St. Louis Railway I22 J2 XXIII. Georgia Pacific Railway ' XXIV. Oregon & Washington Territory Railroad , 126* 12- XXV. Fort Worth & Denver City Railway, .... ' 128 i2 / XXVI. Richmond & Danville Railroad, XXVII. Cleveland & Canton Railroad, . XXVIII I XXIXJ California Central Railway, . 13410136 XXX. Toledo, St. Louis & Kansas City Railroad, ... r ? 7 XXXI. Atlantic & Pacific Railroad, ....*.'. 138130 XXXII. Milwaukee & Northern Railroad, XXXIII. ) ., XXXIV f Minneapolis & Manitoba Railroad 14210145 XXXV. New York, Woodhaven & Rockaway Railroad, I4 6 I47 XXXVI. New York, Providence & Boston Railroad, XXXVII. Intercolonial Railway ieoto IM XXXVIII. Esquimalt & Nanaimo Railway, . INDEX, . ' m ' ^ TECHNICAL TERMS AND NAMES. THE following list gives the names and their synonyms of some of the more important parts of wooden trestles. In connection with this list see Figs, i and 2, to which the num- bers opposite the names refer. FIG. i. FIG. 2. Bent, Framed, 20. (See page 24.) Pile, 19. " " 6 Cluster. " " 41 Bent Brace, see Sway-brace. Block, see Sub-sill. Bolster, see Corbel. Cap, 3. (See page 12.) Chord, see Stringer. Corbel, Bolster. (See page 31.) Cross-tie, 2. " " 35 Cut-off, 17. " ii Dapping, see Notching. Fender, Guard-rail, i. (See page 35.) Gaining, see Notching. Girt, see Longitudinal Brace. Girder, see Stringer. Guard-rail, Fender, Ribbands, i. (See page 35.) Jack-stringer, see Stringer. Longitudinal Brace, Girt, Wai ing-strip, 22. (See Mortise, 13. [page. 39) Mud-sill, see Sub-sill. Notching, Gaining, Dapping, 18. (See page 30.) Outside Stringer, see Stringer. Packing-block, Packing piece, 5. (See page 32.) Packing-bolt, 7. " " 48 Packing-piece, see Packing-block. Packing-washers, see Separator. Piles, Batter, Inclined Brace, 16. (See page 7.) Vertical, Plumb, Upright, 9. " " 7 Posts, Batter, Inclined, 12. " " 28 Vertical, Plumb, Upright, 10 " " 28 Ribbands, see Guard-rail. [pages 32 and 50.) Separator, Packing-washer, Thimble Spool, 6. (See Sill, 14. (See page 27.) Spool, see Separator. Stringer, Chord, Girder. Track, 3. (See page 32.) Outside, Jack, 4. " " 34 Sub-sill, Mud-sill, Blocks, 15. (See page 2^.) .Sway-brace, Bent Brace, 21. " Tenon, 11. " Thimble, see Separator. Track-stringer, see Stringer. Waling-strip, see Longitudinal Brace. jx 39 12 ABBREVIATIONS. A. & P. R. R. ; Atlantic & Pacific Railroad. B., C. R. & N. R. R.; Burlington, Cedar Rapids & Northern Railroad. B. & M. R. R. R. in Neb. ; Burlington & Missouri River Railroad in Nebraska. C. & A. Ry. ; Chicago & Atlantic Railway. C., B. & Q. R. R. ; Chicago, Burlington. & Quincy Railroad. C., C. & C. R. R. ; Charleston, Cincinnati & Chicago Railroad. C., M. & St. P. Ry. ; Chicago, Milwaukee & St. Paul Railway. C., N. O. & T. P. Ry. ; Cincinnati, New Orleans & Texas Pacific Railway. C. & S. Ry. ; Charleston & Savannah Railway. C. & W. M. Ry. ; Chicago & West Michigan Railway. D., T. & Ft. W. R. R. ; Denver, Texas & Fort Worth Railroad. G., C. & S. F. R R. ; Gulf, Colorado & Santa Fe Railroad. K. C., Ft. S. & M. R. R. ; Kansas City, Fort Scott & Memphis Railroad. K., G. B. & W. R. R. ; Kewaunee, Green Bay & Western Railroad. L. & N. R. R. ; Louisville & Nashville Railroad. M., K. & T. Ry. ; Missouri, Kansas & Texas Railway. N. Y., P. & B. R. R. ; New York, Providence & Boston Railroad. N. Y., W. S. & B. R. R. ; New York, West Shore & Buffalo Railroad. R. & D. R. R. ; Richmond & Danville Railroad. St. P., M. & M. R. R. ; St. Paul, Minneapolis & Manitoba Railroad. S. F. & N. P. R. R. ; San Francisco & North Pacific Railroad. S., F. & W. Ry. ; Savannah, Florida & Western Railway. T., St. L. & K. C. R. R. ; Toledo, St. Louis & Kansas City Railroad. UHI7ERSIT7 C A TREATISE ON WOODEN TRESTLE BRIDGES. I. CHAPTER I. INTRODUCTION. THE. amount of Wooden Trestling in this country is very large, but few probably realiz- ing its extent unless they have thoroughly studied the subject. At the present time there are about 2400 miles of single-track railway-trestle in the United States,* of which we can con- sider about one quarter as only temporary, to be replaced by embankment. " Of the remain- ing 1800 miles, at least 800 miles will be maintained in wood." This 2400 miles is composed of about 150,000 separate structures having about 730,000 spans or more. Table I gives the general data as to the amount of bridges and trestles, and the average rate per mile of track on some of the more important systems. TABLE I. Amount of Bridging and Trestling in Different Parts of the United States, and the Rate per Mile of Track. (COOPER'S TABLE No. 3.) System of Railroad or State. Miles of Road. Total Length of Bridges and Trestles in feet. Lin. ft. of Bridges and Trestles per Mile of Road. New York Central and West Shore Railroads, New York, Lake Erie & Western Railroad, . 2,894 I.5H T, q86 364,722 95,509 AAt QOO 126 63 1 1O Roads in Pennsylvania, .... . " " New England, .... . Wabash System, . Missouri Pacific System, ... . Chicago, Milwaukee & St. Paul Railroad, St. Louis & San Francisco Railway, Denver & Rio Grande Railroad, . . . Union Pacific Railroad . 4-352 2,199 1,636 4,707 5,727 1,441 1,458 4-754 2 ACK 336.957 176,700 I6O,O25 566,953 614,736 130,075 IO2,I95 276,032 522 67Q 77 80 98 120 107 90 70 58 121 Queen and Crescent System, . . . Roads in Illinois, ..... . " " Michigan, .... . " " Iowa, . . . . . . . I-I39 8,539 4.151 7 778 299,222 707,535 249-345 I O49 386 231 t * S !/: rt 2 2 % rt-o 5 "u->C ^M w rt o -a 2 Vic '' rt m Vic Q .0 5" 3^3 Jd 3 C S ^ c Q ^ O 3 O y u oJ ^ O P' n Q. 3 2 "3 ^ 3 C ^ ^ c Q ^Q O. 3 2 "3 ^ 3 c " o 2 U O o a J3 .SjJfW !5 S J ?3 J2 J2 BuJ " u O o G J3 -w"^ Wfi u O o J3 ^3 .y^w ^ S 5 I/) t/5 V V FIG. 59. NEW YORK, LAKE ERIE & WESTERN R. R. FIG. 61. NEW YORK, WOODHAVEN & ROCKAWAY R. R. FIGS 54 TO 61. DETAILS OF CORBELS. extent they are very useful, but they also have many disadvantages. They give extra support to and consequently strengthen the stringers ; but for various reasons, as the stringers should not be made lighter on this account, this does not count for much. They also add stiffness 31 A TREATISE ON WOODEN TRESTLE BRIDGES. to the stringer-joint, but sufficient stiffness for all intents and purposes may be obtained from a well-designed joint without them. They add to the cost, not only in labor and lumber, but also require the use of a considerably larger amount of iron. They increase the number of joints, and hence the places for the lodgment and beginning of decay. If, however, it is thought desirable to use them, the different ways of fastening the stringers to them, and they in turn to the caps, may be seen in Figs. 54 to 61. Corbels should be notched down about I in. over the cap. A peculiar and rather com- mendable method of separating the corbels and stringers from each other by cast-iron blocks, as adopted on the Chicago & Northwestern Railroad, is shown in Fig. 60. Stringers. A stringer should be placed immediately beneath each rail, and in order to guard against defective timber it ought to be "split" or composed of two or more pieces. These pieces should be separated from each other by either cast-iron washers or spools, or wooden packing-blocks, or both. A considerable difference exists in the present practice as to the amount of separation. It varies all the way from nothing to 13 in. From i in. to 2 in. is a very good distance. In Figs. 62 to 72 are shown a number of cast-iron separators, and in Figs. 73 to 82 a number of wooden packing-blocks. Among the latter, those having the general form of Fig. 75 are to be preferred. These are to be placed immediately above the caps. Those packing-blocks which are notched are of course placed so that.the cap fits FIG. 62. FIGS. 63, 64. FIG. 65. FIG. 66. FIG. 67. FIG. 68 FIG. 70. o .> FIG. 71 FIG. 72. SCALE ,,, 2" 3" 4" B" e" 7 s" 9 ip i i*ia . i i i i i ' ' i i i FIGS. 62 TO 72. CAST-IRON SEPARATORS. FIG. 73 FIG. 74. FIG. 75. FIG. 77- e FIG. 78. FIG. 79. FIG. 80. FIG. 8 1. FIG. 76. FIG. 82 7 8 9 1|0 FIGS. 73 TO 82. WOODEN PACKING-BLOCKS. into the notch. Frequently the packing-blocks made of the heavier material are used merely as splice-blocks, they being separated from the stringers by thin cast-iron separators, such as is shown in Fig. 67. Many fasten the stringers together by intermediate bolts placed either at the centre of the span or at regular intervals along it. Separators or packing-blocks are of course required to be placed between the stringers wherever these bolts are located. With good timber and spans of 12 ft. to 14 ft. these intermediate bolts are not necessary, and may be just as well omitted as not. A TREATISE ON WOODEN TRESTLE BRIDGES. 33 When it is possible, the stringer-pieces should be long enough to extend over two spans and the joints broken. Various styles of stringer-joints and ways of arranging intermediate bolts are shown in Figs. 83 to 98. The arrangement shown in Fig. 83 is to be greatly pre- S ur FIG. 83. PENNSYLVANIA R. R. FIG. 84. WISCONSIN CENTRAL R. R. FIG. 85. N. Y., P. & B. R. R. JMJj-L ~-- t K i ' 3 *=$ FIG. 86. B. & M. R. R. IN NEB. FIG. 87. A. & P. R. R. FIG. 88. GEORGIA PACIFIC RY. 3 - ur FIG. 89. C., N. O. & T. P. RY. FIG. 90. CENTRAL R. R. OF GA. FIG. 91. GULF, COL. & SANTA FfiR.R V E5D ? I A I a 7 f E;4 -* i *l * i |_ ! ^ > 5 o ! < "i^ n - S ^~~ i !> "y slT 1 ' j! ' ^ ii 8 ' s c. ^ jjjlf; | B i nigl * * ^ j . v ^ f fit 4 i- J 1. . i FIG. 92. D., T. & FT. WORTH R. R, FIG. 93. CHICAGO & W. MICH. Rv. FIG. 94. CHICAGO & ATLANTIC RY. . ii : * li U 3 I f Sli T > t- i; L_ s T3J FIG. 95. B. ; C. R. & NORTHERN R.R. FIG. 96. SAN F. & N. PACIFIC R. R. FIG. 97. ST. P., MIN # M. RY. FIG. 98. OREGON PACIFIC R. R. FIGS. 83 TO 98. DETAILS OF STRINGER-JOINTS. 34 A TREATISE- ON WOODEN TRESTLE BRIDGES. ferred, because, should the support for any reason become weakened, the joint, when it settles as a weight comes upon it, closes at the top and tends to open at the bottom. Now the lower bolts act somewhat as a fulcrum, and the effect will be to tend toward splitting the stringer from these bolts to the nearest end. As this arrangement gives the most material where there is the greatest liability to split, and consequently at the weakest point, it forms the strongest kind of a joint. Such joints as those shown in Figs. 91, 97, and 98 cannot be condemned too strongly, and are always to be avoided. Those illustrated in Figs. 87, 88, 89, 90, 92, 93, 94, and 96 are also poor on account of the packing-bolts being so close to the end of broken stringer-pieces, and also, in some cases, on account of there being too few of them. That in Fig. 92 would be an excellent joint were the lower bolts placed a foot or so farther apart. The joint shown in Fig. 86 is said by Mr. I. S. P. Weeks, Chief Engineer C., B. & Q. R. R. west of the Missouri River, to have proved very efficient. It has carried an engine over after the bent has been washed out. The bolts holding the stringer-pieces together, and which are called packing-bolts, should be long enough to extend clear through from face to face of the complete stringer, and allow of placing a cast-iron washer under both nut and head. When the stringers are not fastened directly to the caps they should be notched over r j them I in. A method for holding the stringers in place, and f=M^^MM = ^^^^S^ :: | which is becoming quite general, is shown in Fig. 99. It con- I~J \ \ sists of a piece of 3 in. X 12 in. plank, fastened, outside of each II LV 1/v-J \j* stringer, to the cap by four log-screws or by spikes. The stringers in their turn are kept at the proper distance apart either by a spreader made of the same material or by fasten- ing the ties to them. The size of the stringer-pieces in cross-section will vary with the span, variety of timber, and weight of the traffic. U FIG. 99. STRINGER FASTENING. They should be of sufficient dimensions to prevent any considerable deflection by a passing train. For long spans, or on lines having heavy loads and engines, each stringer should be composed of three pieces ; in other cases two are sufficient. The practice of the Pennsyl- vania Railroad in this respect is given in Table IX. TABLE IX. Trestle-stringers, Pennsylvania Railroad Standard. Dimensions of Stringers. Clear Span. Number of Pieces under each Rail. Width of each Piece. Depth of Stringers. 10 ft. 12 " 2 2 8 in. 8 " 15 in. 16 " 14 " 16 " 2 3 IO " 8 " 17 " 17 " A " jack-stringer," composed of a single piece, should always be placed under either end of the ties, as in Fig. 99. By such an arrangement many advantages are secured. The A TREATISE ON WOODEN TRESTLE BRIDGES. 35 principal one is in case of a derailment, when, if the ties give way, the cars are not liable to fall to the ground as they otherwise might. As the ends of the ties are supported, the chances are very much in favor of their not being broken in such a case. Thus the factor of safety is largely increased. These outer stringers should be long enough to extend over two spans, and should always be securely fastened to the caps by a drift-bolt through either end and the centre. The ends of the stringer-pieces are generally butted together. There are two excep- tions to this otherwise universal rule: in the trestles on the San Francisco & North Pacific Railway, Fig. 96, the ends are separated | in., and in those of the Chicago & Northwestern Railroad, Fig. 60, they are bevelled I in. Several roads have adopted the policy of trussing stringers having a span of 14 ft. or over after they become three or four years old. This end is accomplished on the Pontiac, Oxford & Port Austin Railroad, Geo. A. Nettleton, Chief Engineer, by arranging an iron rod and pieces of rail as shown in Fig. 100. While this treatment has a very beneficial effect in some respects, and adds considerably to the strength of , the structure, still it seems as though the men in charge of the trestles, as well as the inspectors, would be FlG " IOO -- TR USSING STRINGERS. tempted to rely too much upon this extra strength, and allow timber to remain in service which should for safety have been removed long before. The carelessness which would thus tend to be inculcated, would prove very dangerous on the majority of roads. Ties. Ties may be of 6-in. X 8-in. timber, sawed, and should have a length of 12 ft. They should be notched over the stringers I in., and if outside stringers are used with notched guard-rails they need not be otherwise fastened. In other cases they should be spiked to the stringers. There are many different ways of arranging the spikes. Some fasten every third or fourth tie only, while others spike every tie. It is always better to stagger the spikes or arrange them zigzag, as in Fig. 101. Figs. 101 to 109 show several of the different ways of arranging these fastenings. Opinions as to the spacing of the ties vary. They are placed anywhere from 12 in. to 24 in. from centre to centre. The closer together they are put the better; they should never be spaced with centres over 12 in. apart, leaving 6-in. openings between the ties; 9-in. centres are far better even than 12-in. On the West Shore Railroad small blocks 4 in. thick X 8 in. square are spiked to the stringers between the ties in such a manner as to act as a cover for the space between the stringer-pieces (Fig. 101). While these blocks serve a good end by preventing "bunching," and in keeping out the rain and moisture, they are hardly advisable because of their interfering with the free circulation of the air between the separate pieces of the stringer, as well as on account of their preventing the penetration of the sunlight into these places. Often when the ties are not notched, and it is desired to use some other form of fasten- ing than spiking, dowel-pins, made of f-in. iron 5 in. long, may be resorted to. They may be arranged as in Fig. 109. Guard-rails. Guard-rails serve two principal purposes : first, to keep the train from leaving the bridge in case of a derailment ; and second, to aid in keeping the ties in their proper places, and give stiffness to the floor system. They should always be employed, and where an outside stringer is used should be placed immediately above it. They need not be 36 A TREATISE ON WOODEN TRESTLE BRIDGES. made of very heavy timber, nor should they be too light; 6 in. X 8 in., with the narrow face down, is a very good size. The length may vary, using such timber as can be most conven- iently obtained ; still it is better to have them from 16 ft. to 20 ft. long. Of course greater length is in no wise objectionable, except that it is rather more difficult to obtain, and hence i:: ITV UUUIJULI FIG. loi. N. Y., W. S. & B. R. R. FIG. 102. PENNSYLVANIA R. R. FIG. 103. TEXAS & PACIFIC RY. V/rn I I . T_J L-J I l boatspih* PI ~] ~\ ~i ~i 71 . A 3- .-.- ~ ^ - = * '-' ~ K '- ' o u V u L L. L L L LD . FIG. 104. T., ST. L. & K. C. R. R. FIG. 105. K. C., F. S. & M. R. R. FIG. 106. ST. P., M. & M. RY. fn 1 1 (' 3 /' -^ n n o n n n C ~1 4 ^ -. _ - - -'- h. t/iB'iKfbQafspikt - r- - -- * *l 3 I 1 ; f IT-rnTTVI 111 I 5 I 1,1 \rj |!!l TTTf r r -T. ^/sw*** py -s_ - .; " I o ---- - p - V .-.-. - 5 3 C3 1 r i ^> J J L _J t _ _ 1 FIG. 107. C., C. & C. R. R. FIG. 108. M., K. & T. RY. FIG. 109. L. & N. R. R. FIGS. 101 TO 109. FLOOR SYSTEMS. more costly. There are a number of forms of joints in use for connecting the pieces together. Many of these are shown in Figs, no to 115. The ordinary halved joint, Fig. 114, is an excellent one, and fully answers all requirements. The joints should always come immediately over a tie and be broken ; i.e., those on opposite sides should be over different ties, no two joints coming over the same tie. A bolt should extend through the joint tie and outside stringer. The guard-rail should always be notched down at least I in. over each tie. r~r A TREATISE ON WOODEN TRESTLE BRIDGES. 37 mm g g FIG. no. N. Y., W. S. & B. R. R. FIG. 111. PENN. R. R. FIG. 112. T., ST. L. & K. C. R. R. 2 FIG. 113. C., M. & ST. P. RY. FIG. 114. R. & D. R. R. FIG. 115. N. Y. ELEV. ROADS. FIGS, no TO 115. GUARD-RAIL JOINTS. The ends of the guard-rails at either end of the bridge ought to be rounded off 01 cut at an incline, as in Figs. 116 and 117. Every tie should be fastened to the guard-rail in some way, especially when they are not fastened to the stringers. A bolt should be put through the guard-rail at every fourth or fifth tie, and should extend through the outside stringer. The balance of the ties may FIG. 116. FIG. 117. be spiked or fastened by lag-screws. Spiking is much cheaper, a -in. X GUARD-RAIL ENDS. zo-in. boat-spike being employed. If lag-screws are used, a f-in. X 8-in. screw is a very good size. A wrought washer is to be placed under the head of each lag-screw, and a 3-in. to 3^- in. cast washer under the head and nut of each bolt. The screw or nut ends of the bolts should be placed up so that they may be more easily inspected and tightened. It is not necessary to countersink the nuts of the bolts or the heads of the lag-screws ; in fact it should not be done unless absolutely unavoidable, as the holes form a basis for the lodgment of water, and thus are apt to prove very harmful. At either end of the bridge the guard-rails should extend at least from 20 ft. to 30 ft. on to the embankment, and be flared to such an extent that their extreme ends will be the gauge of the track from the rails. They should be supplemented by bumping-posts (Fig. 118). These, however, will be spoken of later on. It is better, though of course more costly, to face the inside upper corner of the guard-rails with angle-iron. This overcomes to a very large extent the tendency of the wheels to override the guards, by preventing the wheels from cutting into them. Frequently the upper edges of the guard-rails are bevelled. This is bad practice, as it reduces the effective height of the guard, and tends to assist the wheels in overriding them. Inside guard-rails, either of wood or of a second steel rail, placed about 2\ in. from the rails, are claimed by many to be much more efficient than outside guards. Outside guards, it is said, tend to turn a derailed truck at right angles to the moving train, while inside guards turn it towards the track. It is urged against inside guards that articles such as brake-shoes, etc., are very apt to fall between the guard and the rail, and thus increase the number of derailments. However this may be, there is no doubt that inside guards are very service- able, but their use is no reason for omitting the use of outside guards, which should always be employed. In regions where it is necessary to use snow ploughs on roads where the pilot comes very close to the rails, inside guards should never rise above the top of the rails. 38 A TREATISE ON WOODEN TRESTLE BRIDGES. Fastening down Floor System. There are a number of different methods of fastening the floor system to the bents, some of which have already been described. Drift-bolting the stringers to the caps is the one most generally employed. The drift-bolts should extend a FIG. 118. EMBANKMENT END OF TRESTLE, SHOWING FLARED GUARD-RAILS AND BUMPING-POSTS. generous distance into the caps, say at least 8 in. One drift-bolt through the continuous piece of each compound stringer, per bent, especially if the ties are notched, is amply suffi- cient (Fig. 1 19). u u D r 1 1 FIG. 119. DRIFT- BOLTING-DOWN STRINGERS. FIG. 120. BOLTING-DOWN STRINGERS. Among the other ways is that of using a f-in. bolt with nut in place of a drift-bolt (Fig. 120). This bolt is sometimes made long enough to extend through a tie placed immediately above the cap, in which case it usually passes through the space between the stringer-pieces 4 = FIG. 121. FIG. 122. BOLTING-DOWN STRINGERS. (Fig. 121). Several roads employ but one bolt, placed on the centre line, as in Fig. 121. Frequently the floor system is not fastened to the bents at all, its weight being depended on to keep it down, and blocks arranged as shown in Fig. 99, and Plates n, in, XXIV, XXVII, etc.. Part II, to keep it in place and line. In this case girts, securely fastened to the posts at their upper ends, should always form a part of the structure, no matter how low it may happen to be. CHAPTER VI. BRACING, COMPOUND-TIMBER TRESTLES, HIGH TRESTLES, TRESTLES ON CURVES, AND MISCELLANEOUS TRESTLES. Sway-bracing. It is seldom that any sway-bracing will be needed for either pile or framed bents under 10 ft. high. For those from 10 ft. to 20 ft. in height a single X of 3-in. X iQ-in. plank is all that is necessary. One plank should be placed on either side of the bent, and extend from the upper corner of the cap across to the lower end of the opposite batter- pile, terminating just above the ground, or to the opposite lower corner of the sill if a framed bent. The braces should be bolted to the cap, to each pile or post, and to the sill by a f-in. bolt, with a cast washer under both head and nut. Often either lag-screws or spikes are used for attaching the braces, but bolts are to be preferred. For bents over 20 ft. high but not over 40 ft. two X's of sway-bracing should be employed. It is both more convenient and more economical to make the upper X of a constant length, say from 1 5 to 20 ft., and put the odd lengths in lower one. A horizontal stick on each side of the bent separates the X's. These sticks are also made of 3-in. X lO-in. plank, and bolted to each post or pile. Whenever a pile or a cap extends beyond the other so that the sway-braces cannot lie flat, either the larger of the two should be sized down so as to be level with the smaller, or else the smaller should be blocked out to meet the brace. In general, the former method is the better one. Counter-posts. When framed bents approach a height of 40 ft., they are frequently stiffened by the use of counter-posts rather than sway-bracing, though sometimes by the use of both. The employment of counter-posts requires the dividing of the bent into two stories by means of an intermediate sill. Plates XV, XIX, XXI, XXIII, XXIV, Part II, show several methods of using counters. They are more generally employed in very high work, and for further particulars in regard to them the reader is referred to the section on High Trestles. Longitudinal Bracing. There is considerable variation in the methods of longitudinal bracing employed, some bracing every bay, others only every third or fourth ; some arranging the braces diagonally or latticed, others horizontally, and still others in what might be called a laced form. Examples of all of these forms are shown in Plates XVI, XXIX, XI, Part II. All possible combinations of these, especially of the last two, are employed, as well as many modi- fications and adaptations. Plate XI illustrates that which may be called the laced form, and is the standard on the Pennsylvania Railroad. The ends of the braces are cut in the form, and the edges of the caps and sills chamfered, as in the detail drawing. Each piece is fastened to both cap and sill by a heavy cut spike. There is but one stick of 8-in. X 8-in. material to each bay, and it is placed in the centre line of the trestle. When horizontal bracing, such as shown in the side elevation in Plate XXIX, Part II, is used, there should be a stick placed 39 40 A TREATISE ON WOODEN TRESTLE BRIDGES. immediately above the sill on the outside of each post, and one immediately above the horizontal piece of the sway-bracing. Lateral Bracing. Lateral bracing, such as is illustrated in Plate ix, Part II, adds very greatly to the stiffness of a structure.* It is made of two 6-in. X 6-in. timbers placed diag- onally across, from cap to cap, immediately beneath the stringers and bolted together at the intersection by a f-in. or |-in. bolt. The timbers are usually slightly notched into the caps, and fastened in place by several heavy spikes. This kind of bracing is coming into quite general use, and is now one of the essentials of many new designs. When used, the longi- tudinal bracing need not be so extensive. It is said that where lateral bracing is employed the trestle keeps in line much better. Compound-timber Trestles. There is a style of construction very largely in vogue which may be denominated as above. The members, such as caps, sills, posts, etc., either wholly or partly, are each composed of two or more pieces bolted together instead of being a solid stick. The parts are generally separated from each other to a greater or lesser degree. While the life of the structure may be somewhat shortened in some cases, it is claimed that this disadvantage is more than offset by the ease of repairs, as any part can be replaced with a minimum amount of labor, and without causing the least disturbance in the running of trains or impairing the safety in anyway. On account of the smaller size of the timber, much more thoroughly seasoned and better quality material can be obtained. It can also be much more easily inspected. The sticks are generally 6 in. X 12 in. Several plans of this style of struc- ture are given in Plates XXVII, XXVIII, XXIX, xxx, and XXXII, Part II. High Trestles. Trestles above 40 ft. in height may be classed as high trestles. Usually they are divided into two or more decks and stories. The height of the decks depends upon several considerations, but is regulated to a certain extent by the length of timber that can be most economically procured. The decks and stories should be of uniform height through- out any one trestle, or at least those upon the same level should be, in order to simplify things as much as possible, and the odd lengths put into the lowest one. It is in the designing of these rather exceptional structures, especially when the extraordinary height of one hundred or more feet is reached, that there is every opportunity for the full employment of a very high grade of constructive skill. There may be said to be four classes of high trestles : ist. Those in which the posts are continuous, being made up to the required length by joining single sticks together, end to end, with a butted joint, using splice-blocks or other means. 2d. Those in which the decks, though separate and distinct, are still intimately joined together by means of framing ; the sill of one deck acting as the cap of the one beneath. 3d. Those in which the decks are separated entirely by purlins or other means. 4th. Those in which the posts, and frequently other members, are each made up of two or more pieces placed together side by side. In this latter group are included cluster-bent trestles. * Adopted as standard on the Boston & Albany Railroad; the Toledo & Ohio Central Railroad, C. Buxton, Chief Engineer. A TREATISE ON WOODEN TRESTLE BRIDGES. 41 Those of the first class are generally erected where good quality long timber of large size may be easily and economically procured. In this group stories are formed by bolting horizontal pieces of timber to the posts, one on either side, at the proper heights. Counter- posts, or what may be called inside batter-posts, are often introduced, a new set being put in at every other story, and continued down to the main sill. This class of trestle is shown very clearly in Part II, Plates XV, XVI, and xvill. In Plates XV and xvm the employment of counters is depicted. Classes 2 and 3 are resorted to when but comparatively short timber can be procured, and for several reasons are, in the writer's judgment, rather to be preferred, especially the third class, to the continuous-post group. The second class hardly needs any enlargement, as the mere defining of it at once describes its peculiarity. The posts are generally connected with sills and caps in this type by mortise and tenon joints. All posts should of course come immediately beneath those in the deck above, and be in the same line with them, forming to all intents and purposes a continuation of them. Illustrations of this type are given in Part II, Plates xix to xxii. In the third class the bents of each deck are distinctly separate^eing framed entirely by themselves. The lower-deck bents are erected, and then purlins laid along on the caps in such a way as to come directly under the posts of the deck above, the bents of which are of course placed directly over those of the one below. Purlins are laid on the caps of these, and the next deck erected on top of them. This is continued until the necessary height has been attained. The purlins should be firmly fastened to the caps on which they rest either by ordinary bolts or by drift-bolts. The sills should also be secured to the purlins underneath them in the same manner. For illustrations of this construction see Plates XXIII to XXVI. This style offers many advantages for ease of erection, which will be more readily appreciated when that subject is treated of. The fourth class may be subdivided into two groups, namely, those in which the posts, and sometimes other members, are built up by bolting two or more pieces together, keeping them separated a little from each other (see Part II, Plates xxvil, XXX, XXXI, etc.), the majority of them might almost be called plank trestles, and those in which each post is made up of four smaller posts, two of the smaller posts always being continuous over any one story : these are known as cluster-bent trestles. Both of these styles are claimed to have a number of advantages over those built with single sticks of large dimensions. Among them may be mentioned the ability to secure better material, both as respects quality and seasoning, on account of the pieces being smaller ; greater economy and ease in the cost of erection ; and especially greater facility for making repairs. It is also claimed that they can be much more thoroughly, easily, and certainly inspected. While it is said that their life is hardly as long as that of the others, still the advantages enumerated, it has been stated, greatly offset this disadvantage. Besides* they may be kept in a much safer condition. In all of the different styles the bents should always be thoroughly sway-braced, each story and deck having its own set of braces. There should always be, also, a set of longitudinal braces to each deck. As a rule these are of the horizontal type. It should not be attempted to economize in the amount of timber by reducing either the number or the size of the girts. 42 A TREATISE ON WOODEN TRESTLE BRIDGES. Scanting the amount of longitudinal bracing is in no case real economy : it is in fact outrageous, tending to great danger to human life. Frequently two adjacent bents every three or four bents apart are connected by diagonal longitudinal braces so as to form, in effect, towers similar to those of iron trestles. While this is an excellent plan, the longitudinal bracing of the intermediate spans should not be left out, as is generally the case; for while the tower construction adds considerably to the stiffness of the structure as a whole, it is no excuse whatever for weakening the remaining parts. To the writer it seems that the best form of high trestle is the cluster-bent type, with every third bay braced diagonally so as to form a tower, and with the intermediate bays braced with horizontal sticks at every deck, a 3 X 10 in. plank being placed on each side of every post. The plentiful use of counter-posts is also to be recommended. For giving lateral stiffness to the structure, the lateral bracing described on page 40, and illustrated in Part II, Plate IX, is very effective, and should be used whenever possible. Considerable economy may be effected in trestles of great height by spacing the bents farther apart, say thirty feet, and supporting the floor on a deck truss. Such a construction is shown in Part II, Plates XXXIII and XXXIV. The floor system for high trestles is of course the same as that for the lower structures, and which was discussed fully in Chapter V. A far more thorough knowledge of the various practice in the treatment of these struc- tures may be obtained by the careful study of the plates in Part II, than could be im- parted by mere descriptive matter, and so the reader is referred to them. Trestles on Curves. Of course, whenever it is possible, building a trestle on a curve should be avoided. Sometimes, however, this cannot be helped, and then we have to resort to the best means at our command to increase their strength and safety. It is preferable to place the bents on radial lines, especially where the curve is a sharp one. The bracing of all kinds should be heavier and more abundant than where the structure is on a tangent. It is also well to give the batter-posts, especially those on the outside of the curve, as much incli- nation as possible, a batter of 3^ in. to 4 in. per foot not being out of the way, so as to increase the breadth of the base, and enable the trestle to better resist the centrifugal force of the train. Lateral bracing should always be employed on curved trestles, as it tends to -save the structure considerably from the racking it otherwise receives from the train. There are six different ways of elevating the outer rail in common use. The first is by cutting the piles or posts so as to give the cap the proper inclination; the second, by tapering the tie, as in Plate xxxvi, Part II ; the third, by placing wedge-shaped blocks between the tie and the stringer, and bolting them to the former, as in Fig. 123 ; the fourth, by shiming up the track by wedge-shaped blocks placed on top of the ties, and securely spiked to them, as in Fig. 124; the fifth, by placing a bolster or corbel under the stringers on one side and not on the other; and the sixth, by notching or sizing down one end of the cap, as in Fig. 125. This latter method is in use on the Clinch Valley Division of the Norfolk & Western Railroad, and the dimensions given in the figure are for a 6 curve. The other methods arc in use on numerous roads throughout the country. One very serious objection urged against the second method is the splitting of the tie by A TREATISE ON WOODEN TRESTLE BRIDGES. 43 the jarring of the trains; another, the increased cost of the tie, because a tie having the cross- section of the largest end has to be paid for. When this method is used, the face on which the fibres are cut across diagonally should always be placed down. n~TY Wv* FIG. 123. FIG. 124. H* a/g ' +7T 3 /' i^ FIG. 125. FIGS. 123 TO 125. METHODS OF ELEVATING TRACK ON CURVED TRESTLES. Examples of trestles built on curves are given in Part II, Plates IX and XXXVI. Double-track Trestles. Double-track trestles, as a rule, are little else than two single track trestles placed side by side and intimately joined together. The caps and sills should always be continuous. The two batter-posts or piles which would come in the centre are replaced by a single vertical post or pile, or else entirely omitted, and a heavy guard-rail is bolted to the ties about half-way between the inside rails. An outside or "jack" stringer should always be placed beneath this guard-rail, and secured firmly in place. No scanting of the fastening on account of its interior position should be allowed. Plates IX and XXXV to XXXVH, Part II, show several double track trestles. Knee-braced Trestles. On unimportant branch lines, where the traffic is light and the trestles high, considerable economy in timber is attained by using the knee-braced type of trestle. In this form every other bent is omitted, making the spans just twice the ordinary length. The stringers are strengthened by placing a short straining-beam beneath them, and running knee-braces from either end of it down against the posts. Many engineers object very strongly indeed to using this form of construction at all. Plate XVI, Part II, shows a form of this type of trestle, which is the standard on the Norfolk & Western Railroad. Round-timber Trestles. It frequently happens that it is rather difficult to obtain sawed timber, and extensive hewing is both expensive and unnecessary. In this case the trestle is built of round timber. This form of structure is exceedingly cheap, and if well built is very serviceable, though rather rough and unfinished in appearance. Trestles with Solid Floors. On the line of the Louisville & Nashville Railroad, between Mobile and New Orleans, there are some trestles of very peculiar construction. The 44 A TREATISE ON WOODEN TRESTLE BRIDGES. floor is made in the form of a trough and filled in with earth. The ties and rails are then laid on top of this filling, the same as on an ordinary embankment. For certain climates and regions this construction has much to recommend it. It is especially adapted to mild south- o ern climates, and is almost absolutely protected against destruction by fire from cinders dropped by a locomotive. All of the timber should be thoroughly creosoted Plate VIII, Part II, shows, very clearly, one of these trestles. CHAPTER VII. IRON DETAILS. Spikes. There are two varieties of spikes used in trestle-building, cut spikes and boat: or ship spikes. Cut spikes (Fig. 126) are fashioned after the same pattern as common nails, and are essentially stamped out of sheet-metal. They should be of good quality and have generous-sized heads. Table X gives the number of cut spikes in a keg of 100 Ibs., and also the weight in pounds of a single spike. TABLE X. Cut Spikes. FIG. 126. FIG. 127. CUT BOAT- SPIKE. SPIKE. Length in inches. No. in Keg, 100 Ibs. Weight of one Spike, Ibs. Length in inches. No. in Keg, loo Ibs. Weight of one Spike, Ibs. * 2900 2IOO 0344 .0476 Si 6 850 775 .1176 .1293 4 1500 .0667 63 575 1739 5" II5O 950 .0869 .1052 7 8 450 375 . 2222 '.2666 Occasionally common nails of the larger sizes have a limited use, and as an aid in estimating,. Table XI, giving their size and weight, is appended. TABLE XL Size and Weight of Nails. Name. Length. No. in a Ib. io-penny common. 3 inches 60 12 3i 44 16 3i 32 20 4 24 3 4i 18 40 5 H 50 Si 12 60 6 IO 8 fence. 2i 5 10 tt 3 34 12 3i 29 These nails are of the same pattern as the spike shown in Fig. 126, but smaller. Boat- spikes are forged from bars of wrought-iron, and are of the general shape shown in Fig. 127. They have a square section, and are sharpened at the end to a kind of blunt chisel-point. This kind of spike is the one most commonly used in building trestles, and is always the kind to be employed in fastening guard-rails to ties and ties to stringers. Table XII gives the 45 A TREATISE ON WOODEN TRESTLE BRIDGES. approximate number of boat-spikes in a keg of 150 Ibs. in heavy-faced type, and the weight of a single spike in light-faced type. TABLE XII. Number of Boat-spikes in a Keg of 150 Ibs. and Weight of a Single Spike. 1/1 -* u 1H "i H | Length in Inches. 3 3* 4 4i 5 5i 6 6J 7 71 8 8* 9 9* IO i 1910 .0785 1585 .0946 1326 .1093 1223 .1226 1025 .1463 A 1010 .1485 963 1557 810 .1851 605 .2479 583 .2572 52i .2879 TV 542 .2767 503 .2982 461 3253 423 3546 402 3731 321 4673 I 340 .4117 312 4839 298 533 280 5357 261 5747 240 .625 223 .6726 A 221 .6787 200 75 190 .7881 180 .2333 170 .8823 1 60 9375 ISO I.OOOO 140 1.0714 130 1.1538 1 140 1.0714 130 1.1538 120 1.25 no 1.3636 IOO 1.5000 Drift-bolts. The common form of drift-bolt is but little else than a very long boat- spike, though other shapes are used quite extensively. They should always be long enough to penetrate the last timber desired to be held to a depth sufficient to give a good firm hold. Fig. 128 gives the forms of bolts in general use, the first one being that most commonly employed. They are usually made of iron hav- ing a section f in. square or a diameter of f in., and for fastening 12-in. caps to posts or piles are generally 20 in. long. Their weight is about as given in Table XIII. TABLE XIII. Weight of Drift-bolts. -f \ V \ L_ J \ J M FK;. 128. DRIFT-BOLTS. Square Section. Round Section. Length in Inches. i" Sq. i" Sq. J" Diam. i" Diam. Ibs. Ibs. Ibs. Ibs. 18 2.9 5-i 2-3 4.0 20 3-2 5-7 2-5 4-4 22 3-5 6.2 2.8 4.9 24 3-8 6.8 3-o 5-3 26 4.1 7-3 3-3 5 .8 The main value of drift-bolts lies in their holding power. Following is a summary of three series of experiments upon this subject:* Ncivs, Feb. 28, 1891. A TREATISE ON WOODEN TRESTLE BRIDGES. 47 U. S. Government Experiments. These experiments were made under the direction of General Weitzal by Assistant U. S. Engineers A. Noble and C. P. Gilbert, in 1874-77, and were published by Colonel O. M. Poe in his report to the Chief of Engineers for 1884. This series was very extensive, but the valuable results obtained are robbed of much of their value by the lack (in the original publication) of suitable comparisons and conclusions. The mean of from 150 to 200 experiments with round and square bolts, both ragged and smooth, in different-sized holes, shows that the resistance after having been driven seven months is 10 per cent greater than the resistance immediately after driving, the different sizes and forms being strikingly uniform. The mean of 150 experiments under various conditions shows that the resistance to being drawn in the direction which it was driven is only 60 per cent of its resistance to being drawn in the opposite direction ; that is to say, the resist- ance to being drawn through is only 60 per cent of that to being drawn back. The mean of 50 experiments shows that smooth rods have a greater holding power, both to being drawn through, and also to being drawn back, than ragged ones, a " moderate ragging" reducing the resistance a little more than 25 per cent, and an " excessive ragging" reducing the holding power more than 50 per cent. Concerning the best relation between the diameter of the bolt and that of the hole, one series of 60 experiments, shows that the holding power of a i-in round rod in a -j-^ hole is greater than in either a i|- or in a |-| hole, the resistance in the i|- hole being 98 per cent, in the -[f 90 per cent, of that in the {-^- hole. On the other hand, another series of 35 experi- ments makes the resistance in a |f hole greater than in a |f or a ff, the first two being prac- tically the same, and the last being only 85 per cent of the first. However, the difference between the two series is not material, considering the nature of the experiments. For a f-in. round bolt, four experiments on each size seem to prove that the holding power in a ^-| hole is about one quarter greater than in a T 9 ^ or an -j--^ hole. For a I-in. square bolt, the holding power in a ||- hole is only a trifle greater than in a |f , and about 20 per cent greater than in a ^f- hole, as deduced from 20 to 40 experiments for each size of hole. The holding power of a i-in. square bolt in a ||- hole was practically the same as for a i-in. round rod in an -j-g-in. hole. There is 25 per. cent more metal in the square drift-bolt, while more labor is required to bore a -ff -in. hole than an j^-in. one ; therefore the round drift-bolt is at least 25 per cent more efficient per pound of metal than the square one. The holding power of a i-in. round bolt in a -ff-in. hole in white pine, when drawn back immediately after driving, is a trifle over 10,000 Ibs. per linear foot of bolt, a mean of 42 experiments on 7 pieces of timber. Twelve experiments on 3 sticks of Norway pine, under conditions similar to the preceding, gave 9000 Ibs. per linear foot of bolt. Experiments upon 4 sticks of hemlock seem to show that the resistance is practically the same as white pine. One-inch round screw-bolts were screwed into ^-|, ||, and T f-in. holes and immediately drawn back, the result being that there was but little difference for the different-sized holes. Half of the bolts had 8 threads to the inch and half had 12, the latter giving a very little the greater resistance. The resistance for the screw-bolts was about 50 per cent more than the maximum resistance of the plain round rods. The report says : " Two classes of blunt points were used : Long, blunt points, tapered back for a distance of i to 2 in. and reduced to a round section, on square as well as round A TREATISE ON WOODEN TRESTLE BRIDGES. bolts, with a diameter less than that of the hole into which it was driven. They were pointed hot. Short, blunt points were reduced in size at an angle of about 45 by cold hammering, the point of the square bolt remaining square, with rounded corners, the intention being more to remove all cutting edges from the point than to reduce it much in size or change the square sections to round." The experiments were not so arranged as to make it possible to draw any reliable conclusion as to the relative merits of the two forms of points ; but if the experiments show anything in this respect, it is that the resistance of bolts having "long, blunt points" is about ten per cent more than those having " short, blunt points." Brooklyn Bridge Experiments. Experiments made in connection with the construction of the East River Bridge by Mr. F. Collingwood and Colonel Paine, and communicated by the former, gave a holding power of 12,000 Ibs. per linear foot of bolt for a i-in. round rod driven into a |f -in. hl e m fi rst quality Georgia pine, and a resistance of 15,000 Ibs. in a T |-in. hole. It was found that in lighter timber containing less pitch the holding power was about 20 per cent less ; and in very dense wood, containing more pitch, about 10 per cent more. University of Illinois Experiments: A third series of experiments was made by Mr. J. B. Tscharner in the testing laboratory of the University of Illinois, and published in full in " No. 4, Selected Papers of the Civil Engineers' Club of the University of Illinois." According to these experiments, the average holding power of a i-in. round rod driven into a T f-in, hole in pine, perpendicular to the grain, is 6000 Ibs. per linear foot ; and under the same conditions the holding power in oak is 15,600 Ibs. per linear foot. The holding power of the bolt driven parallel to the grain is almost exactly half as much as when driven perpendicular to the grain. If the holding power of a i-in. rod in a T f-in. hole be designated as I, the holding power in a |f-in. hole is 1.69; in a T f-in. hole, 2.13; and in a T -|-in. hole, 1.09. The holding power decreases very rapidly as the bolt is withdrawn. Dowels. In place of drift-bolts with point and head, plain iron bars, either square or round, are frequently resorted to. These are not forged or altered in any way, but are placed in the structure in just the condition that they are sheared from the rods, the only precaution taken being to see that they are straight. The ties are frequently dowelled to the stringers. Pins made of f-in. round iron cut into pieces 5 in. long, are of a very good size. They weigh 0.4304 Ib. each. One method of fastening the posts, caps, and sills together is by means of dowels, f in. by 8 in., which weigh about one pound each. The following list gives the weight of one inch of a bar of iron of the various diameters most frequently employed in this kind of work : I inch square, 0.2806 Ib. i " diam. round, . . . 0.2204 " " square, 0.2149 " | " diam. round, . . . 0.1687" " square, 0.1579" | inch diam. round, . . . 0.1240 Ib. | " square 0.1096" f " diam. round, . . . 0.0860 " \ " square 0.0701 " \ " diam. round, . . 0.0551 " Bolts. Bolts for holding the stringer-pieces together, fastening on the braces, guard- rails, etc., are made of f-in. round iron. They vary in length of course, according to the use A TREATISE ON WOODEN TRESTLE BRIDGES. 49 they are intended for. A head should be forged on one end, and a good, deep, well-formed right-hand thread cut upon the other for an appropriate distance. There are three kinds of heads in use in trestle-building: the round or button head, the flat coun- tersunk head, and the ordinary square head (Fig. 129). Square nuts with a thickness equal to the diameter of the bolt, and each side to twice the diameter, are the best. The outer top corners of the nuts and square heads should be chamfered. A cast-iron washer, from 3 in. to 3^ in. in diameter, is to be placed beneath both head and nut of all bolts. The bolts are driven through *^ holes bored in the timber, and which should be -fa in. less in diameter than the bolts, FIG. 129. so as to insure a snug fit. BOLTS. While the weight of the bolt will be somewhat affected by the shape of the head, still the weight given in Table XIV may be used in making up preliminary estimates, as the error will be on the safe side ; i.e., too heavy. TABLE XIV. Approximate Weight of Bolts in Lbs., with Square Heads and Nuts, including both. Length under Head in Inches. Diameter in Inches. 2' f t I i 6 0.59 1. 01 7 O.64 I. 10 8 O.70 1.19 9 0.75 .27 10 0.81 -36 2.IO 3-5 4-23 ii 0.86 44 2.22 3.22 4-45 12 0.92 53 2-35 3-39 4.67 13 0.97- .62 2.47 3-55 4.89 H 1.03 .70 2.59 3-72 5.11 IS 1.08 79 2.72 3-89 5-34 16 .87 2.84 4.06 5.56 17 .96 2.97 4.23 5-78 18 2.05 3-9 4.40 6.00 19 3-21 4-57 6.22 20 3-34 4-74 6.44 21 3-46 4.90 6.66 22 3-59 5.07 6.88 23 3-7i 5.24 7.10 24 3.83 5.41 7-32 In ordering bolts the term "grip" is sometimes employed, meaning the total thickness of the material to be held together, or, in other words, the distance between the inside faces of the washers. Lag-screws. A lag-screw (Fig. 1 30) is little more than a very large wood-screw, with a square head similar to a bolt-head. A hole the full size of the shank should be bored through the first timber, otherwise the screw will not draw the timbers together. For the balance FIG. 130. LAG-SCREW. of the distance the hole should be bored much smaller. Under the head of each screw a wrought washer should be placed. The following table gives the details of the proper size of washer to use for different-sized lag-screws : A TREATISE ON WOODEN TRESTLE BRIDGES. TABLE XV. Proper Size of Wrought Washers. Diam. Lag-screw. Diam. of Washer. Diam. of Hole. Thickness Wire-gauge. No. In 150 Ibs. Weight of one in Ibs. ^ inch if inches -& inch No. 12 4500 0333 * " if " H " " 10 2500 .06 f " 2 \l " " IO t6oo .0938 Separators, Thimbles, Packing Washers. These were described when treating of stringers. They are made of cast-iron, which should be of good quality and free from blow- holes. Table XVI gives their dimensions and approximate weight. TABLE XVI. Details of Cast-iron Separators (see Figs. 62 to 72). Dimensions in Inches. Kind. Diam. of Rims or Ends. Thickness of Rim. Breadth of Rim or Ends. Thickness of Disk or Length of Spool from Outside Face to Outside Diam. of Hole. Diam. of Spool or Smallest Diameter. Weight in Ibs. Face of Ends. Fig. 62 3 I 1 i-7 63 3 1 I i 1 1.03 6 4 3 3 ~g IJ 1 1-5 65 3T 3 ir \ Ii i Ii 2tV 66 2i i I A f 0.6 67 4 I 4i 1 2 5-5 68 4 i 3 i a 3-25 69* 4 1 I i-7 70 4 t 6 1 i* 3-75 7i 3 2 2 i 2 2.5 72 3 i 4 i It i-75 * The six smaller holes are " in diameter. Washers. Cast-iron washers are used very extensively. They are always placed under the heads and nuts of all bolts in the structure. Fig. 131 gives a few of the designs in 8CAte w ,9 i v 2" a* ^ B'. e' FIG. 131. CAST-IRON WASHERS. use, and Table XVII their weight and dimensions. The solid washers are placed under the heads of the bolts, and those having either a slot or second hole in them under the nuts. The purpose of these slots or holes is to enable a nail to be driven in close to the nut after it has been screwed down tight, to serve as a nut-lock. A TREATISE ON WOODEN TRESTLE BRIDGES. TABLE XVII. Details of Cast-iron Washers. Dimensions in Inches. Kind. Weight Fig. 131- Diam. of Back. Diam. of Face. Diam. of Hole. Thickness. in Ibs. A 3 2i I i B 3 If 1 f C 3i 2i I f D 3 2 I I E 2| If 1 i F 3 Ii i f G 4t 2f 1 i H 3 2 f f I 4 2 I f J si 2* T 3 ft f Sim lar to B 3i 2 I f 1.25 " G 4i 2 I f 1-375 As wrought-iron washers are used to a greater or lesser extent in this class of work, a table giving the details of the standard washers as now manufactured, is appended. TABLE XVIII. Showing the Average Number of Wrought-iron Washers in a Keg of 150 Ibs., of each Standard Size, As adopted by "The Association of Bolt and Nut Manufacturers of the U. S." Diameter. Size of Hole. Thickness Wire-gauge. Size of Bolt. No. in 150 Ibs. i i No. 18 A 80.000 f A " 16 i 34.285 f A " 16 i 22.OOO 1 1 " 16 T 5 * 18.500 I A " H f 10.550 Ii i " H A 7.500 If T 9 * " 12 i 4.500 Ii i " 12 A 3.850 If H " 10 i 2.500 2 H " IO f 1. 600 2i H " 9 1 1.300 2i IA 9 i 950 2f it " 9 i* 700 3 it " 9 ii 550 3i H 9 if 450 These washers are merely circles stamped from sheet-iron, with a hole punched through the centre of them. Nut-locks. Special nut-locks are not required in trestle-work. The method of locking by driving a nail close to the side of the nut, through a hole in the washer, as mentioned when treating of cast washers, is as good and cheap a one as could be desired. Nicking the threads of the bolts with a centre-punch, after the nuts have been screwed home, is another very good way.* * This method is used on the Texas & Pacific Railway. CHAPTER VIII. CONNECTION WITH EMBANKMENT PROTECTION AGAINST ACCIDENTS. Connection with Embankment. There may be said to be two principal methods of connecting trestles with the embankment ; viz., by sills built in the embankment itself, and by a pile-bent placed at its edge. There are several ways of arranging the bank-sills. Sometimes they are piled up criss- cross, after the same fashion as in building a crib, several layers high. They should be of 12-in. X 12-in. timber, and at least 10 ft. long, and much better if the crosswise ones are 12 ft., securely fastened together by a drift-bolt wherever they cross each other. It is seldom that more than two sticks are used in each layer ; those of the top layer should be at right angles to the centre line of the road, and placed quite close together over the centre of the crib. Their upper surfaces should be on the same grade level as the caps, so that the stringers will have a good bearing, the stringers being securely drift-bolted to them. After everything is in place earth should be packed in closely both inside and around the crib, and the bank carried out to at least the middle of the first bay. It will frequently be found necessary to protect the end of the bank from being washed away either by a revetment of logs, by sheet-piling, by rip-rap, or by other means. Rather than arrange the bank-sills crib-fashion, some prefer to lay from two to eight or more pieces of the same size timber close together, on the same level and at right angles to the road. In this case, as before, the stringers should be drift-bolted to the bank-sills. With whichever arrangement is used, however, the bank should be allowed to stand as long as possible before putting in the bank-sills, so that it will have time to settle. The preferable way to connect the trestle with the bank is by a bank-bent. This is either a pile-bent of three or four piles, or a light framed bent. In any case the ends of the stringers are usually protected from contact with the earth by a piece of heavy plank nailed across them, called a dump-board. Plate VI, Part II, shows a form of bank-bent. It sometimes happens that it is necessary to plank up behind the bank-bent so as to prevent the embankment spreading beneath the trestle. In this case, if a pile-bent is used, it should be strongly built, and the piles penetrate to a considerable depth, especially if the bent be of any height. It is also well to brace the tops of the piles against the foot of the piles in the next bent, so as to prevent the bank-bent being forced over by the pressure of the embank- ment behind it. If a framed bent is chosen, it should be strong and heavy, and well braced against its neighbor, both diagonally and by girts acting as struts. Tf possible, the girts or horizontal bracing should extend clear across the whole structure, be of heavy material, have butted joints and be well fastened, so as to avoid buckling; in other words, they should fulfil all of the requirements for struts. 52 A TREATISE ON WOODEN TRESTLE BRIDGES. 53 Rerailing Guards. All extensive and all high trestles should be protected by a rerailing guard, and it would be far better if all the trestles were, without regard to their size. Plan and Sections of Rerailer. Elevating Casting and Point. Section oh G H. Section ori E F. Section on'J K.- FIG. 132. LATIMER BRIDGE-GUARD. If this cannot be done, then collision-posts at least should be erected to guard them. Even where rerailing guards are used it is an excellent plan to supplement them by collision-posts 54 A TREATISE ON WOODEN TRESTLE BRIDGES. arranged so as to stop a car, the truck of which has moved half of the gauge or more out of line. This would at least save the bridge, even though it would not prevent an accident. Fig. 118 shows such collision-posts. In Fig. 132, the details of the Latimer bridge-guard, as used on the Savannah, Florida & Western and the Charleston & Savannah Railways, Mr. B. W. Howe, Jr., Chief Engineer, are given. Refuge-bays. On all trestles of any length, say two hundred feet or over, refuge-bays or small railed platforms to receive workmen or track-walkers who may be caught on the bridge by a train should be placed every two or three hundred feet apart. These cost but very little, and are very efficient in insuring greater safety to employees, especially on single- track trestles. Fig. 133 shows an excellent attachment for this purpose. - 40- *^ u FIG. 133. REFUGE-BAY. Every fourth or fifth refuge-bay on trestles over one thousand feet long, especially when on or approached by a curve, should be made large enough to receive the hand-car; and when the section-men or the repair-gang are at work on the bridge they should always be compelled to place the hand-car on the refuge-bay, together with all idle tools, before they begin work. Foot-walks. Some engineers recommend the laying of foot-walks, composed of three or four rows of 4-inch plank, along the centre of the trestle. This, however, for a number of reasons, does not seem desirable, even though it make the life of the track-walker more endurable. Among the objections may be mentioned : 1st. A tendency to make the track-walkers and others careless in their examination of the structure. 2d. It offers a greater temptation to people to make a highway of the trestle on account of the greater comfort and ease with which it may be crossed, and hence encourages the public to trespass upon the railroad company's property, and that upon the most dangerous places. 3d. It increases, very largely, the area for cinders from the engines to fall upon, and hence makes the risk of fire much greater. Fire Protection. As long as wooden trestling is used fire will be one of the most troublesome subjects to deal with. There are several devices, which are now employed more or less extensively, to reduce the danger from this source. ./ TREATISE ON WOODEN TRESTLE BRIDGES. 55 The one most extensively used is to place tubs or half-barrels, which are kept full of water, at Yhort intervals along the trestle. They should never be over two hundred feet apart, and should each be supplied with a pail or generous-sized dipper. The pails should never be made of wood, as they are liable to be found in anything but a serviceable condi- tion when most needed. Both " Indurated fibre" and " Granite" or enamelled iron-ware are excellent materials for this purpose. The water in the tubs should never be allowed to become low, and it should be the imperative duty of the track-walker to see that they are kept full. Common kerosene oil-barrels cut in half make very good tubs. On single-track trestles these are placed on one side upon the ends of two ties, which are purposely made longer than the others for this use. On double-track trestles they are placed between the two tracks. As this safeguard is very cheap indeed, there is no reason why every trestle in the country, without exception, should not be so protected. In the colder portipns of the country there is, of course, the disadvantage of the water freezing in winter, but this is no reason for depriving the public of what little benefit there is in the apparatus during the balance of the year. Railroad companies, for their own sake, should adopt it, as it would frequently lessen the cost of an accident by furnishing immediate means for the extinguish- ment of many a fire in its incipiency, after a wreck has occurred. A second method is to cover the stringers with a strip of sheet-iron about three or four inches wider than they are, before placing the ties, etc., on them. See Plate III, Part II. Common sheet-iron of about No. 27 gauge is very good for this use. The iron should be protected from rust by some means. A good preventive is common tar. Before putting the iron in place it should be warmed, and thoroughly painted all over with the hot tar. A third kind of fire protection is that illustrated in Plate VIII, Part II, in which the trestle has a solid floor which is covered with earth. Not only should means be provided to prevent the spread of and to put out fires that have once started from unavoidable or accidental causes, but every precaution possible to prevent them approaching from the outside should also be taken. The right of way to a width of 15 to 20 ft. from either side of the trestle should be kept perfectly clear of all com- bustible matter of any kind at all times. Not only should this rule be closely observed, but no amount of any moment should be allowed to accumulate outride of this limit. Within it, all weeds and tall grass should be kept closely cut. When construction or repairs are going on, all chips and small blocks should be raked up in a heap at the close of the day, at a safe distance from the work, and set on fire. If the work is being done by contract, the contractor ought to see that this is done for his own protection. When the trestle is on a line in course of construction, the right of way should be thoroughly cleared, the necessary space grubbed, and the rubbish cleaned up and completely burned before erection is allowed to be begun, or at any rate before the trestle is accepted by the engineer or the contractor estimated for the work done. Any trees off of the right of way which are likely to fall upon and injure the trestle should be felled. It is the railroad company's place to obtain permission to do this, though the contractor may be rightly called upon to do the work for which he may be estimated at the same rate as for clearing. CHAPTER IX. FIELD ENGINEERING AND ERECTING. THERE are several methods of laying out the ground preparatory to erecting a trestle. Of course the exact^ method of procedure will depend, to a certain extent, upon the surround- ing circumstances. The centre-line should be run in carefully with a transit, and the stakes, which should be well made and stout, driven firmly into ground. A stake should be placed on the centre-line at each bent, and a tack, located by the instrument, driven in. For a pile-trestle on land the instrument is set up over each centre stake and the proper angle turned off, and stakes driven in on either side at the proper places for the outside piles. The tape is then stretched between the centre and outside stakes, and stakes marking the posi- tion of the inside piles driven in. Some prefer, for framed bents especially, to use hubs in place of stakes, and centre a tack on each one. This, however, is an unnecessary refinement. For framed bents it is preferable to place the stakes, which should be driven down pretty close to the surface in this case, a foot ahead of the centre of the bent. A centre stake and one a little distance out on either side is all that is necessary. A mark is made on the sill half-way between the two vertical posts, and when the bent is put in position this mark is placed opposite the centre stake. Care is taken to see that the sill sets back the proper distance from all of the stakes, 6 in. between the stake and the face of the sill in the case mentioned. Of course when a framed bent has a pile-foundation the piles are located in the same manner as for pile-trestles. When the foundation is of masonry the centre-line in both directions is first laid out and then stakes driven in in such a manner that when strings are stretched between them they mark the outline of the top of the masonry. A mark or stake giving the elevation of the top is also given. After the foundation is in, the centre is marked on top of it. For use on this kind of work a 5 heads, round button ) with a thickness not less than the diameter of the bolt, and the size of its square not less than twice the diameter of the bolt, with a thickness at the centre of not less than three quarters of the diameter of the bolt, and an extreme diameter of not less than two and one half times the diameter of the bolt, countersunk on the under side so as to fit into a cup-washer, with an extreme diameter of not less than twice the diameter of the bolt. A TREATISE ON WOODEN TRESTLE BRIDGES. 65 Cast-iron. All castings must be from good, tough metal, of a quality capable of bearing a weight of five hundred and fifty (550) pounds, suspended at the centre of a bar one (i) inch square, four and one half (4!) feet between supports. They must be smooth, well-shaped, free from air-holes, cracks, cinders, and other imperfections. All iron, before leaving the shop must be thoroughly soaked in boiled linseed-oil. INSPECTION AND ACCEPTANCE. All materials will be subject to the inspection and acceptance of the Engineer before being used. The Contractor must give all proper facilities for making such inspection thorough. Any omission to disapprove of the work, by the Engineer, at the time of a monthly or other estimate being made, shall not be construed as an acceptance of any defective work. PROTECTION AGAINST FIRE. The Contractor must each evening, before quitting work, remove all shavings, borings, and scraps of wood from the deck of the trestle, and from proximity to the bents or piles, and on the completion of the work must take down all staging used in the erection, and burn all shavings, chips, etc., and remove all pieces of timber to a distance sufficient to insure safety from fire. ROADS AND HIGHWAYS. Commodious passing places for public and private roads shall be kept in good condition by the Contractor, and he shall open and maintain thereafter a good and safe road for passage on horseback along the whole length of his work. RUNNING OF TRAINS.* The Contractor shall so conduct all his operations as not to impede the running of trains or the operation of the road. He will be responsible to the Railroad Company for all injuries to rolling-stock or damage from wrecks caused by his negligence. The cost of such damage will be retained from his monthly and final estimates. RISKS. The Contractor shall assume all risks from floods, storms, and casualties of every descrip- tion, except those caused by the Railroad Company, until the final acceptance of the work. LABOR AND MATERIAL. The Contractor must furnish all material and labor incidental to or in any way connected with the manufacture, transportation, erection, and maintenance of the structure until its final acceptance. Disorderly, quarrelsome, or incompetent men in the employ of the Contractor, or those who persist in doing bad work in disregard of these specifications, must be discharged by the Contractor when requested to do so by the Engineer. * This clause may be inserted when the repairs or renewals are made by contract, or on the double- tracking of a road. 66 A TREATISE ON WOODEN TRESTLE BRIDGES. Whenever the Chief Engineer may deem it advisable, he may name the rates and prices to be paid by the Contractors, for such time as he may designate, to the several classes of laborers and mechanics in their employ, and for the hire of horses, mules, teams, etc., and these shall not be exceeded ; and having given due notice to the Contractors of his action in regard to these matters, they shall be bound to obey his orders in relation thereto. The Chief Engineer shall not, however, name a rate or price for any class of labor, etc., higher than the maximum rates being paid by the Contractor paying the highest for that class. INTOXICATING LIQUORS. Contractors will not themselves, nor by their agents, give nor sell any intoxicating liquors to their workmen, or any persons at or near the line of the railway, nor allow any to be brought on the works by the laborers or any other person, and will do all in their power to discountenance their use in the vicinity of the work by persons in their employ. A continued disregard for this clause will, if deemed necessary by the Engineer, be considered as a good and sufficient reason for declaring the contract forfeited. DAMAGES AND TRESPASS. Contractors shall be liable for all damages to landholders, arising from loss or injury to crops or cattle, sustained by any cause or thing connected with the works, or through any of their agents or workmen. They will not allow any person in their employ to commit trespass on the premises of persons in the vicinity of the works, and will forthwith, at the request of the Engineer, discharge from their employ any that may be guilty of committing damage in this respect. They will also maintain any fences that may be necessary for the proper protection of any property or crops. REMOVAL OF DEFECTIVE WORK. The Contractors will remove at their own expense any material disapproved by the Engineer; and will remove and rebuild, without extra charge, and within such time as may be fixed by the Engineer, any work appearing to the Engineer, during the progress of the work or after its completion, to be unsoundly or improperly executed, notwithstanding that any certificate may have been issued as due to the execution of the same. The Engineer shall, however, give notice of defective work to the Contractors as soon as he shall become cognizant of the same. On default of the Contractors to replace the work as directed by the Engineer, such work may be done by the Railroad Company at the Contractors' expense. DELAYS. No charge shall be made by the Contractor for hindrances and delay, from any cause, in the progress of any portion of his work ; but it may entitle him to an extension of the time allowed for completing the work sufficient to compensate for the detention, to be determined by the Engineer, provided he shall give the Engineer in charge immediate notice, in writing, of the detention. EXTRA WORK. No claim shall be allowed for extra work unless done in pursuance of a written order from the Engineer, and the claim made at the first estimate after the work was executed, A TREATISE ON WOODEN TRESTLE BRIDGES. 67 unless the Chief Engineer, at his discretion, should direct the claim, or such part of it as he may deem just and equitable, to be allowed, Unless a price is specified in the contract for the class of work performed, extra work will be paid for at the actual cost of the material remaining in the structure after its com- pletion and the cost of the labor for executing the work, plus fifteen (15) per cent of this total. This fifteen (15) per cent will be understood to include the use of and cost of all tools and temporary structures, staging, etc., and the Contractor's profit, and no extra allowance over and above this will be made. INFORMATION AND FORCE ACCOUNTS. The Contractor will aid the Engineer in every way possible in obtaining information, and freely furnish any which he may possess, by access to his books and accounts, in regard to the cost of work, labor, time, material, force account, and such other items as the Engineer may require for the proper execution of the work, and shall make such reports to him from time to time as he may deem necessary and expedient. PROSECUTION OF THE WORK. The Contractor shall commence his work at such points as the Engineer may direct, and shall conform to his directions as to the order of time in which different parts of the work shall be done, as well as the force required to complete the work at the time specified in the contract. In case the Contractor shall refuse or neglect to obey the orders of the Engineer in the above respects, then the Engineer shall have power to either declare the contract null and void and relet the work, or to hire such force and buy such tools at the Contractor's expense as may be necessary for the proper conduct of the work, as may in his judgment be to the best interests of the Railroad Company. CHANGES. At any time during the execution or before the commencement of the work the Engineer shall be at liberty to make such changes as he may deem necessary, whether the quantities are increased or diminished by such changes, and the Contractor shall be entitled to no claim on account of such changes beyond the actual amount of the work done according to these speci- fications at the prices stipulated in the contract, unless such work is made more expensive to him, when such rates as may be deemed just and equitable by the Chief Engineer will be al- lowed him ; if, on the other hand, the work is made less expensive, a corresponding deduction may be made. QUANTITIES. It is distinctly understood that the quantities of work estimated are approximate, and the Railroad Company reserves the right of having built only such kinds and quantities, and according to such plans, as the nature or economy of the work may, in the opinion of the Engineer, require. ENGINEER. The term Engineer will be understood to mean the Chief Engineer, or any of his author- ized Assistants or Inspectors, and all directions given by them, under his authority, shall be 68 A TREATISE ON WOODEN TRESTLE JBRIDGES. fully and implicitly followed, carried out, and obeyed by the Contractor and his agents and employees. PRICE AND PAYMENT. The prices bid will include the furnishing of materials, tools, scaffolding, watching, and all other items of expense in any way connected with the execution and maintenance of the work, until it is finally accepted and received as completed. The Contractor will only be paid for the piles, timber, and iron left in the structure after completion. No wastage in any kind of material will be paid for except in the case of piles, when the " piles' cut-off," and which cannot be used on any other part of the Contractor's work, will be paid for at the rate agreed upon. After the material cut off is paid for it is to be considered as the property of the Railroad Company, and is neither to be removed nor used by the Contractor without the consent of the Engineer, and then only upon the repay- ment of the price which has been paid for it. The piles and " piles' cut-off " will be paid for by the lineal foot, the former to be driven and in place. The timber and lumber will be paid for by the thousand feet, board-measure, remaining in and necessary to the completed structure. The iron will be paid for by the pound actually remaining in the structure after its com- pletion. The masonry for foundations will be paid for by the cubic yard. The excavations for foundations will be paid for by the cubic yard. The retained percentage will not be paid on the cost of any single structure until the final estimate is due on the entire work embraced in the contract. If the building of the trestle is let with the contracts for grading or under a general con- tract, then many of these clauses may be omitted, as they are merely general requirements applicable to all classes of work. Many of the clauses would also be omitted or changed some- what under the different conditions existing in different sections of the country. The effort has been made, however, to make them as generally applicable and as concise as possible, and all of the clauses inserted have been selected on account of their general excellence and justice to both Contractor and Railroad Company. A form of proposal is as follows : THE RED RIVER RAILROAD COMPANY. PROPOSAL FOR BUILDING TRESTLES. The undersigned hereby certify that they have personally and care/idly ex- amined the location and the plans and specifications for the trestles on the first, second, and third divisions on the line of the Red River Railroad. Having made such examinations, the undersigned hereby propose to the said Red River Railroad Company to furnish all the material and do all the work required A TREATISE ON WOODEN TRESTLE BRIDGES. 69 for the construction and completion of said first, second, and third division trestles, in accordance with said specifications and plans, and upon the acceptance of this pro- posal do hereby bind themselves to enter into and execute a contract for the same at the following PRICES: Material. . Unit. Approximate quantities. May be more or less. R ite. Foundation excavation Earth, . . . . Cubic yard. 2? 22 Solid rock, . . . Foundation masonry, Cubic yard. Cubic yard. 15 56 5 90 CO Round white-pine piles, not creosoted, . . .< .< .< cut o ff ( " oak " " " Lineal foot. Lineal foot. Lineal foot. 1500 35 06 Etc. etc. etc. Square yellow-pine piles, not creosoted, . . Lineal foot. Lineal foot. IOOO 35 Etc. etc. etc. White-pine timber, not creosoted, erected, . Oak Etc. etc. etc. Round oak piles, creosoted, Lineal foot. M. B. M. M. B. M. Lineal foot. loo M. 10 M. 172? 3 40 08 00 oo 7C " " " cut off Etc. etc. etc. White-pine timber, creosoted, erected, . . Etc. etc. etc. Wrouerht-iron, Lineal foot. M. B. M. Pound. 750 M. 10,000 3 30 00 04 Cast-iron, Pound. 1 2 so O2i The undersigned further propose to commence work within ten days from date of contract, and to complete the same within sixty days from date of contract. Signed this sixth day #/" January, 1890. Name of Firm, SMITH BROS. & COMPANY. f GEO. H. SMITH. By \ WM. R. SMITH. I ED. C. BROWN. Post Office address of Contractor : 97 Great George Street, New York City, New York. This form in blank, for filling out, should be printed and bound with the specifications, together with the agreement or contract. Those portions of the form printed in Roman type are left blank for filling in by the bidders, excepting in the table of prices, where only the prices are left blank. CHAPTER XI. BILLS OF MATERIAL, RECORDS, AND MAINTENANCE. ONE of the most perplexing duties to the young engineer is, perhaps, the making out of proper bills of materials for trestle-work. The following is an example of a properly made out bill of material : TRESTLE No. 6. DIVISION No. 2; RESIDENCY No. 4. BILL OF TIMBER. No. of Number Size Feet Total Bent. of Pieces. B. M. feet B. M. I H eight, 9 f eet. 2 Cap. 6" x 1 2" xi 4' o" 1 68 2 Plumb-posts. I2"XI2"X 8'0" 192 2 Batter-posts. I2"XI2"X 9'0 216 I Sill. 12" x 12" x 1 2' 4" 148 8 Blocks Mud-sills. I2"XI2"X 2' 6" 240 964 2 H eight, 13 feet. 2 Cap. 6" x 1 2" xi 4' o" 1 68 2 Plumb-posts. 1 2" X 1 2" X 1 2 1 O" 288 2 Batter-posts. 12" x 12" x 1 3' 2" 316 I Sill. 12" x 12" x 14' 2" 170 2 Sway-braces. 3"x io"x i6'6" 83 8 Blocks Mud-sills. I2"XI2"X 2' 6" 240 1265 3-H eight, 10 feet. 2 Cap. 6"xi2"xi4'o" 1 68 2 Plumb-posts. I2"X I2"X 9'0" 216 2 Batter-posts. 12" X I2"x IO' l" 242 I Sill. I2"XI2"X 12' 8" 152 2 Sway-braces. 3"xio"xi4'o" 70 8 Blocks Mud-sills. 1 2" XI 2"^ 2' 6" 240 1088 F loor Sys tern and Miscellaneous Parts : 8 Bank-sills. I2"X 12" X 12' 0" 1152 10 Stringers and Jack-stringers. 8"xi6"x25'o" 2667 4 Stringers. 8"x 1 6" xi 2' 6" 534 51 Ties. 6 v x 8"xi2'o" 2448 9 Guard-rails. 6"x 8"x2o'o" 720 7521 Grand Total, . . 10,838 J BILL OF IRON. No. of Pieces. Name. Use. Size. Weight. - Wrought Iron. 24 Drift-bolts. Stringers to Bank-sills. f " sq. x 24" 26 Drift-bolts. Stringers to Caps. f" sq. x 24" 6 Drift-bolts. Sills to Mud-sills. f " sq. x 20" 1 02 Boat-spikes. Ties to Stringers. y x 12" 150 Boat-spikes. Guard-rails to Ties. V'XI2" 26 Bolts. Guard-rails to Jack-stringers. "x3i" 12 Bolts. Qips to Posts. f " x 22" 16 Bolts. Sway-bracing. J" X 20" 32 Bolts. Packing for Stringers. i" X 22" Tot al, Cast Iron. 172 Washers. Under heads and nuts of Bolts. I"X3" 32 Separators. Between Stringers. 2" X 3" Tot al, Signed, Jan. 25, 1890. WILLIAM Boss, Resident Engineer. 70 A TREATISE ON WOODEN TRESTLE BRIDGES. 71 A copy of all such bills as these should be made in a letter-book. In making out the estimates of timber in feet, B. M., the contractor should always be allowed the full size of any stick between the extreme ends of the tenons, and where the ends or tenons are required to be cut on a skew, the full size for the length with square ends required to cut the piece. The following is the rule for finding the number of feet, B. M., in any stick of timber, or in lumber one inch or over in thickness : Multiply the breadth and thickness in inches together, and divide by twelve. Multiply this result by the length in feet and fractions of a foot, and the final result will be the number of feet, B. M., in the stick. Putting this in the form of an algebraic expression, we have Feet b = breadth in inches ; / = thickness in inches (when one inch or over) ; L = length in feet and fraction of a foot. When the lumber is less than one inch in thickness it is always counted as though it were a full inch thick. It will be found that if such a table as that shown below be made out for bents up to a moderate height, varying by six inches, and blue prints of it sent to the different resident and division engineers, considerable labor and time will be saved, and many annoying, and at times serious, errors avoided. NORTH AMERICAN RAILROAD COMPANY. BILL OF TIMBER FOR STANDARD TRESTLES. PILE. PILE. Height from surface of Ground to top of Cap. Caps 6" x 12" Sway-braces 3" x 10" Intermediate Caps 3" x 10" Feet B. M. Height from surface of Ground to top of Cap. Caps 6" X 12 Sway-braces 3" x 10" Intermediate Caps. 3" x to" Feet B. M. Length Length Length Length Length Length Ft. Ins. PCS. Ft. Ins. Ft. Ins. Ft. Ins. Ft. Ins. Ft. Ins. Ft. Ins. Ft. Ins. 5 o 2 14 o 1 68 8 5 6 2 14 o 1 68 8 6 6 o 2 14 o 9 o 6 6 2 14 o 9 6 7 o IO O 2 14 o 2 16 6 251 7 6 10 6 II O A TREATISE ON WOODEN TRESTLE BRIDGES. FRAMED. Height Caps Plumb-posts Batter-posts Sill Sway- braces Intermediate Caps Mud-sills of Sill to top of Cap. 3" x 10" Feet B M Length. Length. Length. Length. Length. Length. Length. Ft. Ins. Ft. Ins. Ft. Ins. Ft. Ins. Ft. Ins. Ft. Ins. Ft. Ins. Ft. Ins. 5 o 2 14 o 2 4 6 2 4 6 I 16 o 8 2 6 816 5 6 6 o 6 6 7 o 7 6 8 o 8 6 9 o 9 6 10 o 10 6 II General. Each trestle will require : 8 Bank-sills 12 in. X 12 in. X 12 ft 1152 ft. B. M. 4 Dump-boards 4 in. X 8 in. X 1 1 ft. 4 in 121" " " Stringer-pieces 8 in. X 16 in. X 25 ft., contain each. 267 " " " Ties 6 in. X 8 in. X 12 ft. " " ... 48" " " Guard-rails 6 in. X 8 in. X 20 ft. " "... 80" " " Many other devices for furnishing aid in making out bills of material have been in- vented, and are used to a greater or lesser extent in the various offices throughout the country. One of the most notable of those which have come to the Author's notice, and of which the originator is not known, is that of drawing a bent to a large scale, say three-quarters of an inch to the foot, on paper that will not vary much with changes in the atmosphere. The sills for heights varying by regular amounts six inches is very good are then drawn in. When the length of any part, for any height of bent, is needed, it can readily be scaled directly from the drawing. Construction records in detail are, of course, made out each month for all of the trestle-work built since the previous estimate was taken up. The thoroughness and com- pleteness of these records vary considerably on different roads. Following are some forms of construction records as kept on the Norfolk & Western Railroad. These records are very complete, and are to be recommended. A TREATISE ON WOODEN TRESTLE BRIDGES. 73 MASONRY EXHIBIT OF TRESTLE-FOOTINGS. Show cross-sec- tion of irregular and stepped foot- ings, also skew- bents. CJ J3 Zfj 3 a 93UBJS1Q LENGTH OF FOOTING. a tf tt c u d U V J ELEVATIONS. BOTTOM OF MASONRY. Distance from centre. i Centre. V H-l Distance from centre. Top OF MASONRY. 1 Centre. I GROUND. 1, Pi Centre. i o x *J4-I U JS U C 1/5 g 2 rt <^ fc. l"o| o p to This sheet is 13^ in. long by 8| in. wide, and is ruled horizontally in blue ink, with five lines to the inch. It is indorsed on the back for filing as follows : NORFOLK & WESTERN RAIL- ROAD. CONSTRUCTION DEPARTMENT. MASONRY EXHIBIT OF TRESTLE-FOOTINGS, Trestle No Section No Estimate No 18.. Contractor. . . Cubic Yards. This indorsement is so placed that it will be on the outside when the sheet is folded into four parts across its length so as to make a bundle about 3$ in. by Win. 74 ./ TREATISE OM WOODEN TRESTLE BRIDGES. NORFOLK & WESTERN RAILROAD CO. Timber Estimate No 18. Trestle No Section No Res Contractors. East End of Stringers, Sta West End, Sta Length feet. STATION. || SHOULDER TO SHOULDER. OVER ALL. Plumb Post. Outside Batter Post. Inside Batter Post. Sill. Diagonal Bracing. Longitudinal Bracing. No. Length. 'No. Length. No. Length. No. Length. No. Length. No.' Length. Add Tenons, Totals, SUMMARY. fl isions. in U N (75 u E 5 .c 5c 5 tn U u 6 CU "o c o . V Q be ^ " - 1 cl '3 - " " CuOhS toU-S u ^c/i Q J rcd! HOS o A TREATISE OF WOODEN TRESTLE BRIDGES. 75 This sheet is of the same size and indorsed upon the back in the same manner as the foregoing one. The indorsement is as follows : < o ttJ hJ OS w C/3 w 4 os O UJ UJ I CO UJ H UJ CO UJ DC f- 00 3 ' Now, if no more than one trestle is put upon any one sheet, the sheets may be bound in their proper order upon the completion of the road, and will then form excellent records for the use of the Maintenance of Way Department. These blanks are, of course, filled out and signed by the Resident Engineer, and their summaries entered upon the " Detail Item Sheet" of the Residency for the corresponding month. These should then be forwarded to the Division Engineer, who compiles the following report from those of the several Residencies under him: NORFOLK & WESTERN RAILROAD COMPANY. Estimate No 18 Division. BRIDGE, TRESTLE AND TIMBER ESTIMATE. Contractor. DESIGNATION OF ^ STRUCTURE. in CHARACTER OF STRUCTURE. IRON BRIDGES. WOODEN BRIDGES. TIMBER DELIVERED. TIMBER FRAMED. TRESTLE ERECTED. IRON, BOLTS, ETC. REMARKS. Length Out to Out. Length Out to Out. Pine. Oak. TOTAL TO DATE PREVIOUS ESTIMATE NO. CURRENT ESTIMATE. 7 6 A TREATISE OF WOODEN TRESTLE BRIDGES, This sheet is 7 in. by 17 in., and is intended to be folded once each way. One half of the back is ruled for a summary as follows : SUMMARY. ITEMS. PKKVIOTS RSTI.MATK. ClIRKENT KSTIMATK. TOTAL TO DATK. RATE. AMOUNT. Certified b\ TOTAL AMOUNT. On one half of the remaining half of the back is the following indorsement for filing purposes : DC V -- Lu CQ o: ts, > ? k CJ '>J ^ h- K. H* ~s H Q Ui rt ~^ o Y < LLJ Q $ ( > H^ cop oJ 1 1 ^"^ C/5 < r" > , fcX) " LU ^ rt 4-> t/5 4-i . ~ "^ V 5 1 C CO | C O 3 UO4I Longitudinal Bracing. 3- * . \i % a ! N o s- J2 rt~ 3 rt o u V H * ? ? m N O\ Stringers. vo ! * m N "I "dD o O. * m N - dB3 31B -ipauuaiui 'pu [[is Xaois Foundation. 3 c 1 u 3 8 * m N | H SSBJ3 "JII3H jo jaqumfsl -8 1 'aj*CI jaquinf^ aapug O p S OJ J3 O OH (U a a o U3 S >, 05 *0 c 03 (U 3 03 X J= 03 ^ *-> o o3 TJ" C, 27 TO 32 FT. HIGH. PLATE III. STANDARD PILE-TRESTLES, ATLANTIC & PACIFIC RAILROAD. 90 A TREATISE ON WOODEN TRESTLE BRIDGES. 9 i STANDARD PILE-TRESTLE, ATLANTIC & PACIFIC RAILROAD. PLATE III. (See also Plate XXXI.) Dimensions of Timbers. Floor-systems Fig. I, A : Guard-rails, 6 in. X 6 in. X 16 feet. Ties, 6 in. X 8 in. X 9 ft. Stringers, 7 in. X 16 in. X 15 ft. Brace-blocks, 2 in. X 10 in. X 18 in. Fig. i, B: same as above. Bents: Caps, 12 in. X 14 in. X 14 ft. All sway-braces, 3 in. X 10 in. Piles, 12 in. diameter. Dimensions of Iron Details. Floor-system Fig. I, B; Four-piece stringer: Bolts, f in. X 46 in. ; stringer-joints. Packing-bolts, f in. X 30 in. ; guard-rails to stringers. Splice-plates : if in. X* 4 in. X 10 in. ; stringer-joints. Cast separators : 4 in. X 4i in. ; between stringer-pieces ; f-in. bolts. Cast washers : f in. X 4i in. ; under head and nut of each bolt. Spikes : Boat, f in. X f in. X 7 in. ; Cut 2o-penny. Three-piece stringer : Bolts, f in. ; X 34 in. ; stringer-joints ; pack- ing-bolts. f in. X 30 in. ; guard-rails to stringers. Splice-plates, as above. Cast separators, as above. Cast washers, as above. Spikes : Boat, as above. Cut, as above. Bents : Bolts, f in. X 20 in. ; sway-braces to piles. Drift-bolts : f in. X t in. X 22 in. ; caps to piles. Boat-spikes : f in. X I in. X 7 in. ; sway-braces to piles. Cast washers: f in. X 4i in. ; under head and nut of each bolt. Fir,, i. PILE-TRESTLE. FIG. 2. DETAILS OF SEPARATOR AND CAST WASHERS PLATE IV. STANDARD PILE-TRESTLE, CHICAGO & WEST MICHIGAN RAILWAY. 92 A TREATISE ON WOODEN TRESTLE BRIDGES. 93 STANDARD PILE-TRESTLE, CHICAGO & WEST MICHIGAN RAILWAY. PLATE IV. (See also Plate X.) Dimensions of Timbers, Floor-system: Guard-rails, 8 in. X 10 in., notched 2 in. over ties. Ties, 6 in. X 8 in. X 12 ft., notched \ in. over stringers. Stringers, 6 in. X 16 in. X 24 ft. Bent : Cap, 12 in. X 12 in. X 14 ft. Sway-braces, 3 in. X 12. in. Piles, 12 in. diameter. Bank-bent: Dump-plank, 3 in. X 12 in. X 16 ft. Dimensions of Iron Details. Bolts: f in. X 32 in.; guard-rails to stringers. fin. X i6 in.; stringer-joints; packing-bolts. f in. X 1 8 in. ; sway-braces to piles. Drift-bolts: fin. X 24 in. ; stringers to caps. Boat-spikes : f in. X 7 in. ; sway-braces to piles. Cast washers: f in. X in. 3^ in. ; under head and nut of each bolt. Other dimensions as per following table : BOLT. A B C D E F G WEIGHT. f-r 1" V I" 3*" 2" t" T y it Ibs. .t -i" I" It" It" 5" 2f f" f it -it" It" If" It" 6" 3" 1" TV it it" It" If If 7t" 3t t" f it if If" It" 2" 8t" 4t i" *' It -2" 2" -2t" 2i" 9t" 5" it" i' Cast separators : 3 in. X 2 in. thick ; between stringer-pieces. These trestles are built with spans of 12 ft., 14 ft., and 16 ft. SCALE OF FEET 23456789 IO JGross Section, ' : ^^ ev ~i lr~i f i r*Mi i ( i j i i i i ] fr\ f~"i i j i ii n n . . .. > ' . * . '.i' - HH HH D P P P P P-B H B D P- i ) | 1 = _ _ m a - M a H P P n L 3 P P.H B H H P. ', Floor System PLATE V. STANDARD PILE-TRESTLE, MINNEAPOLIS & ST. LOUIS RAILWAY. 94 A TREATISE ON WOODEN TRESTLE BRIDGES. 95 STANDARD PILE-TRESTLE, MINNEAPOLIS & ST. Louis RAILWAY. PLATE V. (See also Plate XXII.) Dimensions of Timbers. Floor-system : Guard-rail, 6 in. X 8 in., notched 2 in. over ties. Ties, 6 in. X 8 in. X 10 ft., white oak. Stringers, 6 in. X 16 in. X 15 ft. 6 in. Packing-block, 6 in. X 16 in. X 5 ft. 4 in., notched 2 in. over caps. Bent: Cap, 12 in. X 14 in. X 14 ft., laid flat. Sway-braces, 3 in. X 12 in. Piles, not less than 1 1 in. diameter. Bank-bent : Dump-plank, old stringers. Dimensions of Iron Details. Bolts : f in. X 41 in. ; stringer-joints ; packing-bolts. Lag-screws : Stringer-brackets to caps. Spikes : Boat, in. X 8 in.; guard-rails to ties. Drift-bolts : | in. X 12 in.; ties to stringers. \ in. X 22 in.; caps to piles. Cast separators : 2 in. wide ; between packing-blocks and stringers. Cast washers : Under head and nut of each bolt. Cast brackets : Stringers to caps. For arguments in favor of and description of this trestle, see Railroad Gazette, April 17, 1891. JO'O KM Casf spool 'for Vt "6o(t Corbel-stringer Separator. Angle-lug. Cast-iron Spool. IRON DETAILS. DETAILS OF STRINGER-JOINT. PLATE VI. STANDARD PILE-TRESTLE, CHICAGO cS: NORTHWESTERN RAILWAY. 96 A TREATISE ON WOODEN TRESTLE BRIDGES. 97 STANDARD PILE-TRESTLE, CHICAGO & NORTHWESTERN RAILWAY. PLATE VI. Dimensions of Timbers. Floor-system : Guard-rails, 8 in. X 8 in. X 16 ft., notched I in. over ties. Ties, 6 in. X 8 in. X 12 ft., white oak. Track-stringers. 10 in. X 14 in. X 16 ft. Jack-stringers : 10 in. X 14 in. X 16 ft. Corbels, 10 in. X 10 in. X 5 ft. 4 in., notched I in. over cap, and used only on bridges of two spans or over. Bents : Cap, 12 in. X 14 in. X 14 ft. Sway-braces, 3 in. X 10 in. Piles, 12 in. diameter. f 3 in. X 10 in. X 16 ft. ; Bank-bent: Dump-plank, \ 3 in. X 12 in. X 14 ft.; L 3 in. X 12 in. X 16 ft. 2 in. X 4 in. X 34 in-; Battens, ' 2 in. X 4 in. X 22 in. Number-boards : i^ in. X 8 in. X 12 in. Dimensions of Iron Details. Bolts: f in. X 2 ft. 3 in.; stringer-joints ; packing-bolts; also stringers to corbels. f in. X 2 ft. 5! in.; guard-rails to stringers. | in. X 3 ft. 4! in.; guard-rails to corbels. f in. X 19! in.; sway-braces to caps and piles. Dowels : i in. X 21 in.; caps to piles. Spikes : Boat, T 5 in. X 5 in. Cut 3O-penny. Cast separators : 3 in. X 4 in. ; as per detail drawing ; between stringer-pieces. 6 in. X 10 in. ; as per detail drawing ; between stringers and corbels, Cast washers : Under head and nut of each bolt. Angle-iron lugs : 2 in. x 3i in. L X 4 in. long ; hold stringers in place. 1 fr-EM-^^^ gnu-~-..- IDK., FIGS, i, 2. FOR HEIGHTS OF 5 FT. OR UNDER. FIG. 3. FOR HEIGHTS ABOVE 24 FT. PLATE VII. STANDARD PILE-TRESTLE, LOUISVILLE & NASHVILLE RAILROAD. n T ,* & 1 1 1 1 1 1 1 1 1 _ i-iijh: ! . i X [ j> ' | s I 1 1 II 1 1 1 1 Plan , omitting Hills end Ties. d V ....-?.. i .f PLATE VIII. PILE-TRESTLE WITH EARTH ROADBED, LOUISVILLE & NASHVILLE RAILROAD. 98 A TREATISE ON WOODEN TKESTLE BRIDGES. 99 STANDARD PILE-TRESTLE, LOUISVILLE & NASHVILLE RAILROAD. PLATE VII. (See also Plates VIII and XVII.) Dimensions of Timbers. Floor System : Guard-rails, outside, 5 in. X 9 in., notched I in. over ties. inside, 4 in. X 9 in., not notched. Ties, 6 in. X 8 in. X 9 ft. Stringers, 8 in. X 16 in. X 30 ft. Corbels, 8 in. X i6f in. X 3 ft., notched I in. over caps. Bents : Caps, 12 in. X 14 in. X 12 feet. Sway-braces, diagonal, 2\ in. X 10 in. horizontal, 4 in. X 10 in. Piles, 12 in. diameter. Girts : 6 in. X 8 in. X 30 ft. Splice-blocks : 2 in. X 8 in. X 3 ft. Dimensions of Iron Details. Bolts: | in. X 27 in.; stringers to corbels.' \ in. X 19^ in.; stringer-joints ; packing-bolts, f in. X 42 in. ; floor-system to caps. Drift-bolts : f in. x 22 in.; caps to piles. Dowels : f in. X 5 in.; ties to stringers. Spikes : | in. x 9 in.; corbels to caps. in. x 8 in.; horizontal sway-braces to piles. \ in. X 7 in. ; diagonal sway-braces to piles. J in. X 12 in. ; girts to piles. Lag-screws : f in. X 7 in.; guard-rails to ties. Cast washers : Under head and nut of each bolt. Cast separators : Between stringer-pieces. PILE-TRESTLE WITH EARTH ROADBED, LOUISVILLE & NASHVILLE RAILROAD. PLATE VIII. (See also Plates VII and XVII.) Dimensions of Timbers. Ties, 6 in. X 12 in. X 10 ft. Side-timbers, 6 in. X 12 in. X 32 ft. Floor-timbers, 8 in. X 12 in. x 32 ft. Caps, 6 in. X 15 in. X 14 ft. Sway-bracing, 3 in. x 10 in. Piles, 12 in. diameter. Revetment-timbers, 12 in. x 12 in. All timber creosoted yellow pine, spiked together. No bolts or mortise and tenon joints used. Eng. News, Oct. 29, 1887. VI* aaf-- U A TREATISE ON WOODEN TRESTLE BRIDGES. 101 STANDARD PILE-TRESTLE, BOSTON & ALBANY RAILROAD. PLATE IX. Dimensions of Timbers. Floor-system : Guard-rails, 12 in. X 12 in., notched if in. over ties. Ties, 10 in. X IO in. X 12 ft., notched \\ in. over stringers. Stringers, 6 in. X H in. X 30 ft. Corbels, 6 in. X 7 in. X 6 ft. Bents: Caps, 6 in. X 12 in. X 12 ft. 6 in. Sway-braces, 3 in. X 12 in. Piles, 12 in. diameter. Lateral braces : 6 in. X 6 in. Dimensions of Iron Details. Bolts : | in. X 23^ in. ; guard-rails to ties. | in. X 16 in. ; stringer-joints; packing-bolts. f in. X 21 in. ; caps to piles. \ in. X 132 in. ; lateral brace intersections. Spikes. Cast separators. Cast washers. rr Jl ZJO i \ --' f p f PLATE X. STANDARD FRAMED TRESTLE, CHICAGO & WEST MICHIGAN RAILWAY. 102 A TREATISE ON WOODEN TRESTLE BRIDGES. 103 SECTION II. FRAMED TRESTLES. STANDARD FRAMED TRESTLE, CHICAGO & WEST MICHIGAN RAILWAY. PLATE X (See also Plate IV.) Dimensions of Timbers. Floor-system : Guard-rails, 8 in. X 10 in., notched 2 in. over ties. Ties, 6 in. X 8 in. X 12 ft., notched in. over stringers. Stringers, 8 in. X 16 in. X 32 ft. Bent: Cap, 12 in. X 12 in. X 14 ft. Plumb-posts, 12 in. X 12 in. Batter-posts, 12 in. X 12 in. ; batter, 2 in. to I ft. Sill, 12 in. X 12 in. Sway-braces, 3 in/X^ 12 in. Sub-sills, 12 in. X 12 in X 6 ft Dimensions of Iron Details. Same as for Plate IV SFee 3 /o spifte 9 /one ~ . . c V" s so J_ * * a L: -^ \ 1 1 c= = 1 h \WrTiron rayqed bolt 1x2- Am 1 1 u 10 1 2 3 4 5 6 7 8 3 10 Feef Scale for fresffes. PLATE XL STANDARD FRAMED TRESTLES, PENNSYLVANIA RAILROAD. IOA A TREATISE ON WOODEN TRESTLE BRIDGES. STANDARD FRAMED TRESTLE, PENNSYLVANIA RAILROAD. PLATE XL Dimensions of Timbers. Floor-system : Guard-rails, 5 in. X 8 in., notched I in. over ties. Ties, 7 in. X 10 in. X 9 ft., notched \ in. to receive guard rails, and in. over stringers. Stringers : Clear Span. Number of Pieces under each Rail. Width of each Piece. Depth of Stringers. 10 ft. 12 " 2 2 8 in. 8 " 15 in. 16 " 14 " 16 " 2 3 - 10 " 8 " 17 " 17 Packing-blocks, 2 in. X 18 X 6 ft. Bents under 20 ft. : Cap, 10 in. X 12 in. X 10 ft. Plumb-posts, 10 in. X 12 in. Batter-posts, 10 in.'X 10 in.; batter, 3 in. to I ft. Sill, 10 in, X 12 in. Bents 20 ft, and over: Cap, 12 in. X 14 in. X 12 ft. Plumb-posts, 12 in. X 12 in. Batter-posts, 10 in. X 12 in., batter 3 in. to I ft. Sill, 12 in. X 12 in. Sway-bracing, 3 in. X 10 in. Bracing : Longitudinal, 8 in. X 8 in. Treenails : Locust, I in. diameter. in. X- in. X- in. X- Dimensions of Iron Details. Bolts: 1 in. X ; guard-rails to ties. ; guard-rail joints. - ; stringer-joints ; packing-bolts. All of above bolts have 2^-in. flat heads, with 2^-in. wrought washer .under nuts. f in. X , sway-bracing to caps and sills; 3-in. wrought-iron washers used. Drift-bolts (ragged): i in. X 24 in.; stringers to caps. Spikes : Boat ? % in. X 9 in. ; guard-rails to ties. in. X 8 in. ; sway-braces to posts. Cut - X , longitudinal braces to caps and sills. Wrought washers : 2\ in. square for f-in. bolt. 3 in. round for f-in. bolt.. 7 S'/s r" ^_^ .oietio'- PLATE XII. STANDARD FRAMED TRESTLE, SAN FRANCISCO & NORTH PACIFIC RAILROAD. 106 A TREATISE ON WOODEN TRESTLE BRIDGES. 107 ,x 8 , i r I | :3irin=c=uJ=o=ip=Q^^ r | r 1 pr pr 1 Tf ' | J. i "_ _: V, /c^y 4 r ^. ^ ty* p f "j t ' w/ \\ \ 1 I : **rv r Ml lj( IJNJI *w* 1 1 1M J i i DETAILS OF FLOOR-SYSTEM. PLATE XIII. STANDARD FRAMED TRESTLE, SAN FRANCISCO & NORTH PACIFIC RAILROAD. STANDARD FRAMED TRESTLE, SAN FRANCISCO & NORTH PACIFIC RAILROAD. PLATES XII AND XIII. Dimensions of Timbers. Floor-system : Guard-rails, 6 in. X 8 in., notched over ties. Ties, 8 in. X 8 in. X 10 ft., notched over stringers. Stringers, 7 in. X 16 in. X 31 ft. 5^ in., notched i in. over caps. Bents: Caps, 12 in. X 12 in. X 14 ft. Plumb-posts, 12 in. X 12 in. Batter-posts, 12 in. X 12 in.; batter, 3 in. to i ft Sill, 12 in. X 12 in. Sway-braces: Horizontal, 4 in. X 8 in. Diagonal, 4 in. X 8 in., 4 in. X 10 in., 4 in. X 12 in. Longitudinal bracing : Girts, 6 in. X 8 in. Sub-sills: 6 in. X 12 in. X 3 ft. Bank-bent: Dump-boards, 3 in. X 12 in. X 14 ft. Dimensions of Iron DetaUs. Bolts : f in. X 37 in. ; floor-system to cap. | in. X 36 in. ; stringer joints ; packing bolts. | in. X 28^ in. ; guard-rails to ties and stringers. f in. X 2i in.; horizontal sway-braces to posts. f in. X 18^ in. ; longitudinal braces to posts. | in. X 17^ in. ; diagonal sway-braces to posts, etc. Drift-bolts : X ; cap to posts. X ; sill to piles. Spikes : 8 in. ; sway-braces to posts, etc. Cast separators: 4 in. X 6 in. thick; between stringer-pieces. Cast washers for f-in. and f-in. bolts. SCALE OF FEET Hp] 2345^7891^ ,1,6, , , ,20 FIG. i. CROSS-SECTION. FIG. 2. ELEVATION. GENERAL PLAN SINGLE-DECK TRESTLES. FIG. 3. PLAN FOR BREAKING SILLS AND STEPPING FOOTINGS ON STEEP SLOPES. PLATE XIV. STANDARD TRESTLES, NORFOLK & WESTERN RAILROAD. 108 fftetfi. SSSW$$$^mS$S^^ SCALE OF FEET OI2345 JO 15 20 FIG. 4. CROSS-SECTION HIGH OR MULTIPLE STORY TRESTLE. PLATE XV. STANDARD TRESTLE, NORFOLK & WESTERN RAILROAD. tog W/ien fewer sfbry ytouM ie /ess than /S/7 in clear . FIG. 5. ELEVATION HIGH OR MULTIPLE STORY TRESTLE. PLATE XVI. STANDARD TRESTLE, NORFOLK & WESTERN RAILROAD. no A TREATISE ON WOODEN TRESTLE BRIDGES. in STANDARD FRAMED TRESTLE, NORFOLK & WESTERN RAILROAD. PLATES XIV, XV, AND XVI. PLATE XIV. Dimensions of Timbers. Floor-system : Guard-rails, 6 in. X 8 in., notched. Ties, 8 in. X 8 in. X 10 ft., notched. Stringers, 7 in. X 15 in. X 25 ft. Packing-blocks, 2 in. X 15 in. X 3 ft., notched I in. over cap. Bent : Cap, 6 in. X 12 in. X 10 ft. Plumb-posts, 12 in. X 12 in. Batter-posts, 10 in. X 12 in. ; batter, 2\ in. to I ft. Sill, 10 in. X 12 in. Sway-bracing: Diagonal, 2 in. X 10 in. Horizontal, 2 in. X 10 in. Longitudinal bracing: Horizontal, 4 in. X 12 in. X 15 ft. 6 in. Diagonal, 3 in. X 12 in. Sub-sills: 4 in. X 12 in. X 2 ft. 6 in. PLATES XV AND XVI. Floor-system : Guard-rails, 6 in. X 8 in. Ties, 8 in. X 8 in. X 14 ft. Stringers, 6 in. X 14 in. X 25 ft. Packing-blocks, 2 in. X 14 in. X 5 ft. Corbels, 8 in. X 1 1 in. X 5 ft. Bent: Cap, 6 in. X 12 in. X 10 ft. Plumb-posts, 12 in. X 12 in. Outside batter-posts, 10 in. X 12 in., and 12 in. X 12 in. Inside batter posts, 8 in. X 12 in., and 10 in. X 12 in. Sway-braces, 2 in. X 10 in. Intermediate caps, 6 in. X 12 in. Sill, 10 in. X 12 in. Longitudinal bracing: Horizontal, 4 in. X 12 in. X 28 ft. Diagonal, 3 in. X 12 in. Knee-braces : Straining-beam, 10 in. X 10 in. X 9 ft. Top chord, 10 in. X 10 in. X 6 ft. 4 in. Bottom chord, 5 in. X 12 in. X 28 ft. Diagonals, 10 in. X 10 in. For method of elevating rails on curves, see Part I, Fig. 125. FIG. i. GENERAL PLANS. W1V*. (Ste" FIG. 3. DETAIL OF JOINT OF DIAGONAL POSTS. FIG. 2 DETAILS OF STRINGER AND POST JOINTS. PLATE XVII. STANDARD FRAMED TRESTLE, LOUISVILLE & NASHVILLE RAILROAD. 112 A TREATISE ON WOODEN TRESTLE BRIDGES. 113 STANDARD FRAMED TRESTLE, LOUISVILLE & NASHVILLE RAILROAD. PLATE XVII. (See also Plates VII and VIII. ) Dimensions of Timbers. Floor-system : Guard-rails, 3 in. X 9 in. Ties, 8 in. X 8 in. X 10 ft. Stringers, 8 in. X 16 in. X 30 ft. Corbels, 8 in. X i6f in. X 3 ft. Bent: Cap, 12 in. X 12 in. X 12 ft. Batter-posts, 12 in. X 12 in. Diagonal posts, 8 in. x 10 in., notched 2 in. each at intersection. Intermediate cap, 6 in. X 10 in. Sill, 12 in. X 12 in. Longitudinal braces : Horizontal, 8 in, x 10 in. x 30 ft. Splice-block, 4 in. x 12 in. Sub-sills: 12 in. X 12 in. X 6 ft. Dimensions of Iron Details. Bolts : | in. X 27 in.; stringers to corbels and intermediate cap to posts. in. X 20 in. ; stringer-joints ; packing-bolts. f in. X 15 in. ; splice-block to girts. in. X 23 in. ; angle-block to posts. Spikes : | in. X 14 in. ; corbels to caps. Dowels : | in. X 5 in. ; diagonal posts to angle-blocks. Cast washers : Under head and nut of each bolt. Cast separators : f in. X ; between stringer-pieces. SCALE OF FEET 1012345678810 f [ IS^ | 2O f FIG. i. CROSS-SECTION. FK;. 2. ELEVATION. [3 . g -m-jiF ~*~"lT is 1 1 FIG. 3. FLOOR-SYSTEM. FIG. 5. DKTAILS OF WALLS AND GIRTS. PLATE XVIII. STANDARD FRAMED TRESTLE, OREGON PACIFIC RAILROAD. 114 A TREATISE ON WOODEN TRESTLE BRIDGES. STANDARD FRAMED TRESTLE, OREGON PACIFIC RAILROAD. PLATE XVIII. Dimensions of Timbers. Floor-system : Guard-rails, 6 in. X 8 in., notched \\ in. Ties, 8 in. X 8 in. X 9 ft., not notched ; and two ties 13 ft. long for every fourth span projecting on alternate sides. Stringers, 10 in. X 16 in. x 16 ft., not notched. Bent: Caps, 12 in. X 12 in. X 12 ft. Plumb-posts, 12 in. X 12 in., in 23 ft. 6 in. lengths. Outside batter-posts, 12 in. x 12 in., in 24 ft. o T V in.* lengths. Counter-posts or inside batter-posts, 10 in. x 12 in., in 24 ft. o T y* in. lengths. Intermediate caps or horizontal sway-bracing, 6 in. X 14 in. Diagonal sway-bracing, 4 in. x 10 in. Sill, 12 in. X 12 in. Longitudinal bracing: Girts, 6 in. X 10 in. X 18 ft., notched i in. Diagonals, 8 in. X 10 in., sized to 6 in. at posts. Packing-pieces, 8 in. thick at intersection of diagonals. Dimensions of Iron Details. Bolts : f in. X 14 in. ; guard-rails to ties. f in. X 30 in. ; through guard-rails, ties, and outside stringers. | in. X 27 in. ; ties to stringers. f in. X 31 in. ; stringers to caps. f in. X 48 in. ; stringer-joints ; packing-bolts. f in. X 1 8 in. ; diagonal sway-braces to posts. | in. X 28 in. ; ] f in. X 22 in. ; bolt at joint H and its companion joint. | in. X 24 in. ; f in. X 31 in. ; . f in. X 24 in. ; intermediate caps to posts. | in. X 1 8 in. ; sill-joint bolts. | in. X 22 in. ; , girt-bolts. | in. X 24 in. ; ( & f in. X 21 in. ; diagonal longitudinal braces to posts. f in. X 27 in. ; intersection of above. Dowels : f in. X 8 in. ; cap and sill to posts ; post-joints. Drift-bolts: X Cast washers : Under heads and nuts of each bolt. Cast separators : i^ in. x ; between stringer-pieces. * So in original blue print, but rather too close to work to in this size timber. Xttf* m PLATE XIX. FRAMED TRESTLE, OHIO CONNECTING RAILWAY. 1X6 A TREATISE ON WOODEN TRESTLE BRIDGES. 117 FRAMED TRESTLE, OHIO CONNECTING RAILWAY. PLATE XIX. Dimensions of Timbers. Floor-system : Guard-rails, 6 in. X 8 in., notched f in. over ties. Ties, 7 in. X 8 in. X 10 ft., notched f in. over stringers. Stringers, 7 in. X 14 in. X 24 ft. Corbels, 10 in. X 15 in. X 5 ft., notched over caps. Bents: Caps, 12 in. X 12 in. X 12 ft. Plumb-posts, 12 in. X 12 in. Batter-posts, 12 in. X 12 in. Counter-posts, 12 in. X 12 in. Intermediate caps, 12 in. X 12 in. Sills, 12 in. X 12 in. Longitudinal braces, 8 in. X 12 in. X 14 ft. FIG. i. CROSS-SECTION. FIG. 2. ELEVATION. FIG. 5. PACKING- WASHER. TT n nl n n u u u SCALE OF FEET I OI23466789IO 16 20 48 69 Fic. 4. SECTION A B, SHOWING BRACING IN EMBANKMENT. FIG, 3, PLAN, S ^.iaK/av-^'-gg^""^ ' 17.^*^1 l^i or.rd.it eo\ v J , f -^ . MI tea rjr FIG. 6. DOUBLE-DECK TKESTI.E. FIG. 7. TRIPLE-DECK TRESTLE. T v f PLATE XX. PRESENT STANDARD T.RESTLE, CHARLESTON, CINCINNATI & CHICAGO RAILROAD. 1x8 A TREATISE ON WOODEN TRESTLE BRIDGES. 119 STANDARD FRAMED TRESTLE, CHARLESTON, CINCINNATI & CHICAGO RAILROAD. PLATES XX AND XXI. PLATE XX. Dimensions of Timbers. Floor-system : Guard-rails, 6 in. X 8 in. X 16 ft. Ties, 7 in. X 8 in. X 10 ft. Stringers, 7 in. x 16 in. X 30 ft. and 15 ft. Bent- Cap, 12 in. X 12 in. X 12 ft. Plumb-posts, \2 in. X 12 in. Batter-posts, 12 in. X 12 in. Sway-bracing, 3 in. X 10 in. Intermediate cap, 12 in. X 12 in. Sill, 12 in, X 12 in. Longitudinal bracing : Horizontal, 6 in. X 8 in. X 16 ft. Diagonal, 4 in. X 10 in. Sub-sills, loin. X 12 in. X 6ft. Dimensions of Iron Details. Bolts: | in. X 15 in. ; guard-rails to ties. | in. X 1 8 in. ; sway-braces to posts. | in. X 28 in. ; stringer-joints ; packing-bolts. Drift-bolts : f in. X I in. X 20 in. ; sills to sub-sills. | in. X f in. X 24 in. ; stringers to caps ; caps to posts. Dowels: f in. X 8 in. ; posts to sills. Spikes, boat : f in. X 8 in. ; girts to posts. \ in. X 10 in. ; ties to stringers. Cast separators : 2 in. x 3 in, ; between stringer-pieces. Cast washers : - - X 3 in. ; under head and nut of each bolt. FIG. i. CROSS-SECTION. FIG. 3. PLAN. SINGLE-DECK TRESTLE. SCALE OF FEET | 2345 10 15 20 2^ FIG. 4. CROSS-SECTION. FIG. 5. ELEVATION. TRIPLE-DECK TRESTLE. PLATE XXI. FORMER STANDARD TRESTLE, CHARLESTON. CINCINNATI & CHICAGO RAILROAD i bo A TREATISE ON WOODEN TRESTLE BRIDGES. 121 PLATE XXI. Dimensions of Timbers. Floor-system : Guard-rails, 6 in. X 8 in. Ties, 7 in. X 8 in. X 10 ft. Stringers, 6 in. X 14 in. X 30 ft. and 15 ft. Corbels, 12 in. X 18 in. X 6 ft. Bent: Cap, 12 in. X 12 in. X 12 ft. Posts, 12 in. X 12 in. Intermediate caps, 12 in. X 12 in. Sway-braces, 2 in. X 12 in. Sill, 12 in. X 12 in. Longitudinal braces : Horizontal, 6 in. X 12 in. X 16 ft. Diagonal, 6 in. X 8 in. Sub-sills, 12 in. X 12 in. X 6 ft. Dimensions of Iron Details. Bolts : fin. X 15 in. ; guard-rails to ties, f in. X 19 in. ; stringers to corbels, fin. X 21 in.; stringer-joints; packing-bolts, f in. X 27 in. ; longitudinal braces to posts, and post-caps to intermediate caps. - X 15 in. ; intersection of diagonal longitudinal braces. Drift-bolts : f in. X f in. X 18 in. ; corbels to cap. Spikes : Boat, T \ in. X 10 in. ; ties to stringers. Cut 5S*S y^" iiu.i.iiL?' SCALE OF FEET y .* t L FIG. '2. -ELEVATION. FIG. 6. SILL AND POST JOINT DETAILS. PLATE XXIX. STANDARD TRESTLE, CALIFORNIA CENTRAL RAILWAY. 135 136 A TREATISE ON WOODEN TRESTLE 3XIDGES. STANDARD FRAMED TRESTLE, CALIFORNIA CENTRAL RAILWAY. PLATES XXVIII AND XXIX. Dimensions of Timbers. Floor-system : Guard-rails, 6 in. X 8 in., notched. Ties, 6 in. X 8 in. X 9 ft, notched. Stringers, 8 in. X 16 in. x 30 ft. Bents: Caps, 6 in. X 12 in. X 14 ft. All posts, 6 in. X 12 in. Intermediate caps, 6 in. X 12 in. Diagonal sway-braces, 3 in. x 12 in. Sill, 6 in. X 14 in. Under part of sill, 8 in. X 18 in. Pile-caps, 12 in. x 12 in. x 6 ft. Packing-blocks between posts and cap-pieces, 6 in. x 12 in. x 42 in., and 6 in. x 12 in. x 2 ft. 9 in. Longitudinal braces, 5 in. X 10 in. x 32 ft. Dimensions of Iron Details. Bolts: Guard-rails to stringers. Stringer-joints ; packing-bolts. f in. X 21 in. ; sway-braces to posts. f in. X 9 in. ; intersection of sway-braces. f in. X 21 in. ; intermediate caps to posts; girts to posts. f in. X 25 in. ; two parts of sill together; brace-pile to pile-caps. Drift-bolts : f in. X 20 in. sill to pile-caps ; caps to piles. Cast washers: Under head and nut of each bolt. Cast separators or spools : 3 in. x and 6 in. x . Cast strap : 20 in. X 3 in. X I in. as per detail ; girts to. posts. A TREATISE ON WOODEN TRESTLE BRIDGES. Floor-system Bent PLATE XXX. STANDARD FRAMED TRESTLE, TOLEDO, ST. LOUIS & KANSAS CITY RAILROAD. STANDARD FRAMED TRESTLE, TOLEDO, ST. Louis & KANSAS CITY RAILROAD. PLATE XXX. Dimensions of Timbers, Guard-rails, 6 in. X 6 in. x 18 ft. Ties, 6 in. x 8 in. x 9 ft. Stringers, 7 in. X 18 in. X 18 ft. Spreader, 3 in. x 12 in. x 3 ft. Brace-blocks, 3 in. X 12 in. X 15 in. Cap, 7 in. X 14 in. X 14 ft. Plumb-post, 6 in. x 10 in. Inclined posts, 6 in, x 10 in. Splice-blocks, 6 in. x 10 in. x 2 ft. Sway-bracing : Horizontal, 6 in. x 10 in. Diagonal, 3 in. x 10 in. Sill, 6 in. x 10 in., 9 in. X 18 in., and 7 in. x 18 in. Longitudinal bracing : Horizontal, 6 in. x 10 in. X 18 ft. Diagonal, 6 in. X 10 in. Dimensions of Iron Details. stringer-joints; packing-bolts. cap-pieces together. post-splices, sway-brace intersections, posts to tenon-blocks, posts Bolts: f in. X 31 in. | in. x 23 in. in. x 21 in. to sill. Lag-screws: | in. x 9 in.; sway-braces to posts, longitudinal braces to posts, etc.; spreader and brace blocks to cap. I in. x 14 in. ; sill-pieces together. Drift-bolts: f in. x I in. X 20 in. ; sill to piles. Cast-separators : 4 in. thick ) , f f r s- m - bolts. 2 m- ) Cast-washers : Under head and nut of each bolt. Splice-plates: T 5 B - in. X 2 in. X 13 in.; stringer-joints. Sheet-iron : No. 27, 30 in. X 36 ft No 27, 24 in. x 14 ft. No. 27, x 34 ft. Also, sheet-iron to cover all places where fire can lodge. covering stringers, covering caps, covering sill. A B FIG. r. FRAMED BENTS. FIG. 2. 40 TO 90 FT. HIGH. PLATE XXXI. STANDARD FRAMED TRESTLES, ATLANTIC & PACIFIC RAILROAD. 138 A TREATISE ON WOODEN TRESTLE BRIDGES. 139 STANDARD FRAMED TRESTLE, ATLANTIC & PACIFIC RAILRC A.D. PLATE XXXI. (See also Plate III.) Dimensions of Timbers. Floor-system : See Plate III. Bent Fig. I : Cap, 12 in. X 14 in. X 14 ft. Plumb-posts, 12 in. X 12 in. Batter-posts, 12 in. x 12 in. Sway-braces, 3 in. x 10 in. Sill, 12 in. X 12 in. Fig. 2 : Cap, 12 in. x 14 in. Plumb-posts, 6 in. X 12 in. Batter-posts, 6 in. X 12 in. Intermediate caps, 6 in. X 12 in. Sway-braces, 3 in. x 10 in. Sill, 8 in. x 12 in., and 12 in. x 12 in. Sub-sills, 12 in. x 12 in. Pile-caps, 12 in. X 14 in. Dimensions of Iron Details. See Plate III. FIG. i. DOUBLE AND TRIPLE DECK FRAMED TRESTLE. ,1 4 i * A'.VJ ' p I B V 'j ' ' . 1 i 1 HJiHI 1 u J w J K.G.B.& W. zr u ^ FIG. 2. FLOOR-SYSTEMS OK TRESTLE-BRIDGES. PLATE XXXII. STANDARD FRAMED TRESTLE, MILWAUKEE & NORTHERN RAILROAD. 140 A TREATISE ON WOODEN TRESTLE BRIDGES. 141 STANDARD FRAMED TRESTLE, MILWAUKEE & NORTHERN RAILROAD. PLATE XXXII. Dimensions of Timbers. Floor-systems A: Ties, 6 in. X 8 in. X 12 ft. Track-stringers, 7 in. X.i6 in. X 30 ft. Jack-stringers, 6 in. or 7 in. X 16 in. x 15 ft. B: Ties, 6 in. X 8 in. X 12 ft. Track-stringers, 12 in. X 15 in. X i 5 ft. Jack stringers, 7 in. X 15 in. X 15 ft. Track-stringer corbels, 10 in. X 12 in. X 6 ft. Jack-stringer corbels, 7 in. X 10 in. X 6 ft. C : Ties, 6 in. X 8 in. x 12 ft. Track-stringers, 7 in. X 14 in. X 16 ft. Jack-stringers, 7 in. X 14 in. X 15 ft. K., G. B. & W. R. R. : Ties, 6 in. X 8 in. X 12 ft. Track-stringers, 7 in. X 14 in. X 16 ft. Jack-stringers, 7 in. X 14 in. x 16 ft. Bent: Cap, 12 in. X 12 in. X 14 ft. Plumb-posts, 12 in. X 12 in., and 7 in. X 12 in. Batter-posts, 12 in. X 12 in., and 7 in. X 12 in. Intermediate caps and sills, 3 in. X 12 in. Sway-braces, 3 in. X 12 in. Main sill, 7 in. x 12 in. Packing-blocks, 3 in. X 12 in. x 3 ft. Pile-caps : 12 in. X 12 in. X 4 ft. Longitudinal braces : 3 in. X 12 in. X 16 ft. Dimensions of Iron Details. Bolts : f in. X 19^ in. f in. X 22^ in. | in. X 29^ in. Spikes : X . 10 IS ?0 25 BO S,S 40 FIG. i. FIG. 2. ELEVATION. PLATE XXXIII. FRAMED TRESTLE, ST. PAUL, MINNEAPOLIS & MANITOBA RAILROAD. 142 A TREATISE ON WOODEN TRESTLE BRIDGES. 143 FRAMED TRESTLES, ST. PAUL, MINNEAPOLIS & MANITOBA RAILROAD. PLATES XXXIII AND XXXIV. Dimensions of Timbers. FIGS. I AND 2. Floor-system: Ties, 6 in. X 8 in. X 12 ft. Track-stringers, 7 in. X 14 in. X 20 ft. Jack-stringers, 7 in. X 14 in. X 20 ft. Floor-beams, 12 in. X 12 in. X 14 ft. Sub-stringers, 12 in. X 12 in. X 30 ft. Corbels, 12 in. X 12 in. X 5 ft. Bent : Cap, 6 in. X 10 in. X 14 ft. Posts, 10 in. X 12 in. Sway-bracing : Horizontal, 8 in. X 8 in. Diagonal, 3 in. X 10 in. Splice-blocks, 6 in. X 12 in. X 6 ft. Sill, 10 in. X 12 in. Pile-caps, 12 in. X 14 in. Knee-braces : Top cord, 10 in. X 10 in. X 10 ft. Diagonals, 10 in. X 10 in. X 18 ft. Longitudinal braces : Horizontal, 8 in. X 8 in. X 34 ft Brackets, 3 in. X 8 in. X 14 ft. SCALE OF FEET FIG. 3. CROSS-SECTION. FIG. 4. ELEVATION. PLATE XXXIV. FRAMED TRESTLE, ST. PAUL, MINNEAPOLIS & MANITOBA RAILROAD. A TREATISE ON WOODEN TRESTLE BRIDGES. 145 FIGS. 3 AND 4, Floor-system : Guard-rails, 5 in. X 8 in. Ties, 6 in. X 8 in. X 12 ft. Track-stringers, 7 in. X 14 in. X 20 ft. Jack-stringers, 7 in. X 14 in. X 20 ft. Floor-beams, 12 in. X 12 in. X 14 ft. Sub-stringers, 10 in. X 12 in. X 30 ft. Bent: Upper cap, 10 in. X 12 in. X 14 ft. Lower cap, 10 in. X 14 in. X 20 ft. Upper posts, 10 in. X 10 in. Main posts, 10 in. X 12 in. Sway-bracing : Horizontal, 8 in. X 8 in. Diagonal, 3 in. X 10 in. . Splice-blocks, 6 in. X 12 in. X 6 ft. Sill, 10 in. X 12 in. Sway-brace splice-block, 6 in. X 8 in. X 5 ft. Sill splice-block, 6 in. X 12 in. X 4 ft. Pile-caps, 12 in. X 14 in. X 4 ft. 6 in. Longitudinal bracing : Horizontal, 6 in. X 10 in. X 34 ft. Brackets, 3 in. X 8 in. Floor trusses: Upper chord, 10 in. X 10 in. X 12 ft. Lower chord, 10 in. X 12 in. X 30 ft. End-posts, 10 in. X 10 in. X 12 ft. Diagonals, 5 in. X 8 in. X 14 ft. Lateral braces, 6 in. X / in. X 14 ft. Foot-blocks : Corbels, 10 in. X 14 in. X 8 ft. Dimensions of Iron Details. Bolts : f in. X I2|- in. ; guard-rails to ties. fin. X 17^ in. ; stringer-joints; packing-bolts. f in. X 27^ in. ; longitudinal braces to posts. -| in. X 28^ in. ; post-joints, f in. X 31^ in. ; diagonal sway-braces to posts. | in. X 4i in. ; horizontal sway-braces to posts. Drift-bolts: fin. X 20 in.; stringers to floor-beams; floor-beams to sub-stringers; sub- stringers to caps ; main sill to pile-caps ; pile-caps to piles. Spikes : Boat, \ in. X 10 in. ; ties to stringers. f in. x 7 in.; sway-bracing to posts; bracket-braces to posts; and longi- tudinal bracing. Iron in trusses : Rods, \\ in. X 11 ft. 4 in. ; between upper and lower chords. Tie-rods, - - x - ; three trusses together. Bolts : - - X ; intersection of panel diagonals. - X 2 ft. 1 1 in. ; end-posts to lower chords. - x 3 ft. 5^ in. ; lower chords and corbels to caps. i ^ -J6'3' VaxJ? FIG. 3. STRINGER JOINT. FIG. i. ELEVATION. SCALE OF FEET FIG. 2. CROSS-SECTION. PLATE XXXV. DOUBLE-TRACK FRAMED TRESTLE, NEW YORK, WOODHAVEN & ROCKAWAY RAILROAD. 146 A TREATISE ON WOODEN TRESTLE BRIDGES. 147 DOUBLE-TRACK FRAMED TRESTLE, NEW YORK, WOODHAVEN & ROCKAWAY RAILROAD. PLATE XXXV. Dimensions of Timbers. Floor-system : Guard-rails, 8 in. X 6 in. Ties, 6 in. X 8 in. X 21 ft. Stringers, 5 in. X 14 in. X 32 ft. 6 in. Corbels, 5 in. X 8 in. x 5 ft. 9 in. Beait: Cap, 12 in. X 12 in. X 24 ft. Plumb-posts, 12 in. X 12 in. Batter-posts, 12 in. x 12 in. Sway-braces, 3 in. x 10 in. Sill, 12 in. x 12 in. Sub-sills, Dimensions ef Iron Details. Bolts: f in. X 13 in. ; guard-rails to ties. f in. X in. ; stringer-joints ; packing-bolts. f in. X - - in. ; stringers to corbels. | in. X ; ) \ stringers to caps, i in. X ; f Plates: in. X 3 in. X 17 in. ; corbel-bolts. Spikes : Ties to stringers. Cast-washers : i in. x 3 in. ; under head and nut of each bolt. iSiiEElip: ^jiSSSJ^^^^i EHr ZJt^SHSE!:: FIG. i.~ SECTIONAL AND SIDE ELEVATIONS, WINTHROP'S COVE TRESTLE. 'soaarocomefatkreen Jfiefiea FIG. 2.-LONG1TODINAL AND TRANSVERSE SECTIONS OF 24 FT. B., WlNTHROrt COVE TRESTLE. ^ Fio.'J SECTIONAL AND SIDE ELEVATIONS, THAMES RIVEK BRIDGE APPROACH TRBSTLE. PLATE XXXVI --TRESTLE PLANS, NEW YORK, PROVIDENCE & BOSTON RAILROAD A TREATISE ON WOODEN TRESTLE B RIDGES. 14. FRAMED TRESTLES, NEW YORK, PROVIDENCE & BOSTON RAILROAD. PLATE XXXVI. FIGS. I AND 2: WINTHROP'S COVE TRESTLE, ON 8 15' CURVE AND 0.714 GRADE. FIG. 3 : THAMES RIVER BRIDGE APPROACH. Dimensions of Timbers, Floor-system : Guard-rails, 8 in. X 8 in. Ties, 8 in. X 1 1 in. X 22 ft. Stringers, 8 in. X 14 in. X 24 ft. \ 2 in. x 14 in- X 4 ft. Splice-blocks, ! 4 in> x , 4 in . x 6 ft . Bent: Cap, 12 in. X H'in. X 23 ft. Plumb-posts, 12 in. X 12 in. Batter-posts, 12 in. X 12 in. Sway-braces, 4 in. X 12 in. Sill, 12 in. X 14 in. Longitudinal braces, 4 in. X 1 2 in. X 25 ft. Purlins, 12 in. X 14 in. Purlin splice-blocks, 4 in. X 14 in. X 6 ft. Foundation: Pile-cap, 12 in. X 14 in. Piles, 12 in. diameter. Brace-piles, 12 in. diameter. Knee-braces: Upper chord, 10 in. X 10 in. X 5 ft. Straining-beams, 10 in. X 10 in. X 21 ft. Diagonals, 6 in. X 14 in. Splice-block, 12 in. X 14 in. X 4 ft. Dimensions of Iron Details. Bolts: f in. X 15! in. ; ) f in. X I 9 iin.;fg uard - railstoties - f in. X i8| in. sway-braces to posts, etc. | in. X 22 in. ; purlin splice. f in. X 26| in. ; upper chord to stringers. f in. X 16 in. ; foot of knee-brace to prevent splitting. -| in. X 27^ in. ; knee-braces to purlins, to packing-blocks, to posts. i in. X 18 in. ; longitudinal braces to posts. i in. x 22J- in. ; ) str i nger ; o j nts . packing-bolts, i in. x 20|- in. ; ) i in. X 34 in. ; batter and sway-brace piles to piles. Drift-bolts: f in. x f in. x 21 in.; stringers to caps, i in. X 18 in. ; sills to posts, i in. X 20 in. ; cap to posts ; pile-cap to piles. Spikes : X ; ties to stringers. f in. X 12 in. ; purlins to pile-caps, f in. X 16 in. ; sills to purlins. Washers, wrought : f-in. bolts ; guard-rail bolts. 4 in. X 4 in. X f in. ; sway-brace bolts. 4 in. X 4 in. X \ in. ; longitudinal brace-bolts. ^, 4 in. X 4 in. X f in. ; sway-brace, pile, etc., bolts. 3 in. x f in. ; purlin splice-bolts. 3^ in. X in. ; stringer-bolts. Cast separators : 3^ in. X i in. ; between splice-blocks and stringers. 3! in. x 4 in. ; between stringers, where there are no splice-blocks. f, -t 'ft Ir -a V>e>wfC"0 Longitudinal Section through A B. Post Spices not shotn frainedthrouqhoitf, to break joints. sopi r.== _j^..nia;^ca.ji.j Section through CD,mtli Erection Gear. Stone Ballast on r,rib nor sfio*n ;_..... PLATE XXXVII. DEEP-WATER FRAMED TRESTLE, INTERCOLONIAL RAILWAY. A TREATISE ON WOODEN TRESTLE BRIDGES. 151 DEEP-WATER FRAMED TRESTLE, INTERCOLONIAL RAILWAY. PLATE XXXVII. As the structure illustrated in Plate XXXVII is exceptional, and had to fulfil unusual requirements, it was thought'best to reprint the full description of the work, as given in the Railroad Gazette of April 9, 1886. It was designed to carry a short branch-line of minor importance across a narrow strait (the Narrows) in Halifax Harbor. The water being from 65 to 80 feet deep, some peculiar features of design and methods of construction were naturally required. The branch as constructed (the Dartmouth Branch) is about 5 miles long. To avoid the trestle it would have been necessary to begin the branch at a point 9 miles or at one 14 miles distant, which would have made it seven or 12 miles long, and required a special train service in operating it. Richmond yard being on the shore of the narrow passage between Halifax Harbor and Bedford Basin, at the most favorable point for bridging it, the structure shown was built instead, permitting the branch to leave the yard inside the semaphore, thus enabling the shunting-engines to do the business on it without in any way interfering with the traffic of the main line. The Narro'ws are about 1500 ft. wide, and from 65 to 80 ft. deep in the channel where the line crosses for a distance of 650 ft. The mean rise and fall of the tide is 6 ft., causing a current through the Narrows of about \\ miles an hour. At spring-tide, with a strong wind, this is sometimes increased to three miles an hour. The bottom is generally compact gravel, mixed with stones and bowlders. In no place could a bar be driven more than 3 ft. ; below that depth was apparently ledge-rock. In severe winters ice forms in Bedford Basin, but owing to the extreme narrowness of the outlet into the harbor, it is held in the basin until decayed by the spring weather. The bridge has a total length of 2050 ft., of which 1204 ft. is on piling, 650 ft. trestling in the channel, and the remaining 196 ft. is a steel swing-bridge. The piling, where in deep water, was well stiffened transversely by brace-piles, which were driven plumb and afterwards drawn over to a considerable angle, when they were fitted to the capping and bolted. The pivot pier for the swing-bridge is of masonry, and has a passage for vessels on each side of 85 ft. in the clear- From the top of the pier to 2 ft. below low-water it is laid in cement, and is circular in form, with a diameter of 20 ft. Thence to the bottom, about 33 ft., it is built square, with a batter of i in 12, and is laid without mortar. Large stones only were permitted to be used in the square portion of the work, and were required to be full bedded throughout and closely fittel. Each course was carefully dressed and put together in the quarry upon a level platform ; the stones were then marked with white paint at all connec- tions with their fellows, and carefully numbered. The courses were then forwarded to the site of the pier, where they were lowered from a lighter, each stone in its proper order, and received by a diver, who, standing on the course last laid, placed them in position, using lines, straight-edge, and spirit-level to insure all possible accuracy. A complete course was frequently laid in a day by the one diver employed, for with the footings once properly levelled he had but little to do to keep the work in good order. Before putting in the foundation courses the sloping bottom was properly benched by the diver, and frequent testings as the work proceeded showed that perfect line and level was being kept. No accident or difficulty of any kind occurred in the construction of the pier, the work being carried on as smoothly and regularly as if in the open air; the steam winch of the lighter working with quickness and precision as the diver signalled his directions. The time occupied in building the pier was 70 days, the same diver being employed throughout. The cost per cubic yard was $23. The trestling across the channel consisted of timber bents, framed as shown on the accompanying draw- ings. The bents were placed 25 ft. apart between centres, and rested on a ballasted timber crib, which had previously been lowered in place. The bents were floated to the site and drawn down to their seat on the cribs by the methods shown in the cuts and described hereafter. The work of putting down the trestling was commenced on the west side of the channel August 8, 1884, and on the east side October 4, 1884. In all 25 bents were put down, in depths generally from 70 to 80 ft. The two sides were connected November 20, i5 2 A TREATISE QN WOODEN TRESTLE BRIDGES. 1884. When the level portion of the channel was reached three bents were sometimes put down in a week. One diver, with occasionally an assistant, worked on each side of the channel. In addition to the travelling derrick shown, a lighter was provided for each side, having a steam-winch for lowering ballast, etc., and a steam-pump for the diver. The correct centring at each bent was given by a theodolite placed at the outer end of the piling, and at slack-water lining in the rope holding the hammer of the floating pile-driver, which had been brought approximately into position, with the hammer raised about one foot from the bottom. When correctly lined the diver was signalled, and a bolt driven into the ground at the centre of the hammer. It is not anticipated that there will be any trouble from worms, as the strength of the current and the large amount of fresh water discharged into the basin render their presence in the Narrows improbable. The wharves in the harbor also show that the nearer the Narrows are approached the less destructive are the worms. It is therefore hoped that the bents below low-water will but rarely require to be renewed, and they have been constructed of sawn hemlock, a cheap and sufficiently good material where secure from decay. The upper or supplementary bents were constructed of white pine, as more durable, and are so con- nected with the lower bents that, though erected as a whole, they can be easily separated and renewed. The work of preparing the bottom for the crib foundation of the bent was as follows : Six flattened tim- bers 10 ft. long and weighted were lowered to the bottom. These were bedded by the diver, and were brought to a uniform level by means of a long straight-edge with spirit-level attached. Where the slope or character of the ground demanded, additional timbers were placed under these bed logs to bring them to the required height, the whole being filled in and about with stone. In fairly level ground the six logs could be bedded by one diver in \\ days. In the worst cases, where the slope of the bottom was i in 2 longitudinally and i in 5 transversely, it took the same diver six days to bed them properly. The crib for each boat was next launched from the ways on which it was constructed, and floated out, and the lines from the winch on the travelling derrick attached to the chain at each end, by hooking on the iron swivel-blocks as shown. The crib was supported until about nine. tons of ballast had been thrown on, when it was lowered to its place on the bed-logs. When near the bottom the diver signalled any slight alteration required in its posi- tion, and the correction was made by side lines. The time occupied in lowering the cribs and finally adjust- them was about i hours. In difficult bottom the diver then proceeded to the next foundation, leaving an assistant to place the remainder of the ballast on the crib. This took about if days to do properly. The bent, which, like the crib, was built on ways on the shore, was next launched and towed to the site, and the lines from the travelling derrick, which passed through the blocks at the ends of the crib, were attached to the sill of the bent. About 10 tons of ballast were next placed in the lockers near the bottom, and the engine was started, drawing the bent gradually downward till, led by the blocks, it rested in its proper place on the crib. It was readily adjusted vertical by a line to the cap, and was then secured by bolting on temporary stays from the end of the bridge. The diver then permanently secured the bent to the crib in the manner shown, by lifting the galvanized-iron fastenings into place, fitting on the cover-blocks and screwing home the nuts. The fastenings were so arranged that they could be thrown back out of the way until the bent was finally settled in place. The time occupied in towing out, hauling down, and adjusting a bent, together with the complete fitting and securing of the fastenings, was in general about \\ days; of this the actual hauling down occupied but a small portion. The permanent stringers were next placed and sleepered, the rails for the derricks laid, and the derrick run out for the next crib. The average cost of the trestling per bent completed ready for the rails was as follows : n M. ft. B. M., hemlock @ $6.47 $7*-i7 9 M. ft. B. M., pine @ 16.00 144.00 12 knees, @ 3.50 42.00 500 Ibs. ordinary iron @ .04?, 22.50 1800 Ibs. galvanized iron, @ .08 144.00 Crib material and work @ 60.00 60.00 Framing, 20 M. ft. B. M., @ 10 oo 200.00 Stone ballast, 66 tons @ .40 26.40 Diving work, @ 108.00 108.00 Incidentals, 31-93 Total, . $850.00 A TREATISE ON WOODEN TRESTLE BRIDGES. 153 The bents number 25, making the total cost of the trestling $21,250, or at the rate of nearly $33 per lineal foot. No accident of any kind occurred in putting down the trestle-bents or foundations, everything working smoothly throughout. All iron to be exposed to the action of salt water was galvanized. The crib founda- tions, from their position, and from being covered with stone, may be considered secure from the action of worms or other destroying agencies. Should a bent at any time require to be removed, it can be easily released from the crib and a new one substituted. In the deepest water the divers worked skilfully and without difficulty, and by coining to the surface for a few minutes every \\ hours, were enabled to do good work throughout the entire day. All levelling and lining under water was accurately done, as proved when the bents were drawn down to their place. The divers were paid $150 per month each, with board; the assistant-divers about half that amount. Steam-pumps were used for supplying air, in preference to those worked by hand, the increased regu- larity of stroke being of importance in deep water.' The current at the bottom, while not so rapid as at the surface, was more changeable, sometimes almost entirely ceasing and then suddenly recommencing, as though restrained temporarily by eddies or cross-cur- rents. The divers, however, were rarely prevented by the current from working satisfactorily. Very severe gales occurred during the construction of the bridge and after its completion. No movement or working was at all perceptible during their continuance. The bridge has now been completed and in operation nearly a year. Trains preceded by two locomo- tives crossing at 15 miles an hour have failed to produce the slightest motion or settlement in any part of the structure. The work was planned and carried through under the direction of Mr. P. S. Archibald, Chief Engineer of the Intercolonial Railway. r-i n n n n -r.i PLATE XXXVIII. STANDARD FRAMED TRESTLE, ESQUIMALT & NANAIMO RAILWAY. 154 A TREATISE ON WOODEN TRESTLE BRIDGES. 155 STANDARD FRAMED TRESTLE, ESQUIMALT AND NANAIMO RAILWAY. PLATE XXXVIII. Dimensions of Timbers, Floor-system : Guard-rails, 6 in. X 9 in. Ties, 8 in. X 9 in. X 13 ft. Stringers, 9 in. X 16 in. Bents: Caps, 12 in. X 12 in. X 16 ft. Plumb-posts, 12 in. x 12 in., and 12 in. X 14 in. Batter-posts, 12 in. X 12 in., and 12 in. X 14 in. Counter-posts, 12 in. X 12 in., and 12 in. x 14 in. Sill, 12 in. x 14 in. Intermediate caps and sills, 12 in. x 12 in., and 12 in. X 14 in. Sway-braces, 4 in. x 10 in. Longitudinal braces, 6 in. x 8 in. Purlins, 6 in. x 12 in. Sub-sills, 12 in. round, flatted. The trestle illustrated is built on a 10 curve. Mr. Joseph Hunter is the Chief Engineer of the road. For further description, see Railroad Gazette, February 6, 1891, p. 89. In the reduction of the drawing of this trestle the figures become so small that the reader is referred to the enlarged details for the dimensions which are also "iven above. INDEX. Acceptance, 65 Accounts, force, 67 Adze, 59 Alabama Great Southern R. R. ( 61 Annual cost, 2 Atlantic & Pacific R. R., 61, 90 Augers, 59 Axe, 59 Axe, broad, 59 Bank bent, 52 sill, 52 Batter piles, 7 " posts, 28 " " , length, 28 " " , template, 29 Bay, refuge, 54 Bent, bank, 52 " , framed, 24 " , height, 30 " , pile, 6 Bents, spacing, 30 Blocks, packing, 32 Board measure, 71 Boat-spikes, 45, 46 Bolts, 48, 49 " , button-head, 49 " , countersunk, 49 " , drift, 46 " , weight, 49 Boring-machine, 58 Boston & Albany R. R., 40, 100 Bracing, latticed, 40 , longitudinal, 39 " , sway, 39 Brantford, Waterloo & Lake Erie R. R., 61 Bridge foremen, 83 " numbers, 83 Bridges, amount, I " , distribution, 2 " , iron, 4 Broad axe, 59 Burlington, Cedar Rapids & Northern R. R., 33. 82 Burlington & Missouri River R. R., 7, 33 Button-head bolts, 49 California Central Ry., 134-136 Cant-hook, 60 Capitalized values, 2, 3 Caps, 29 " , pile, 12 " , split, 1 2, 30 Car pile-driver, 15-19 Cast-iron, 65 separators, 50 washers, 50, 5 1 Central R. R. of Georgia, i, 27, 33, 6r Charleston, Cincinnati & Chicago R. R., 118-121, 27 36 Charleston & Savannah Ry., 54, 83 Chicago, Burlington & Quincy R. R., 34 Chicago, Milwaukee & St. Paul R. R., i, 37, 84 Chicago & Northwestern R. R., 31, 32, 35, 96 Chicago, Rock Island & Pacific R. R., 30 Chicago & West Michigan R. R., 33, 92, 102 Chisel, 59 Cincinnati, New Orleans & Texas Pacific R. R., 33, 61 Cincinnati Southern Ry., 61 Classification, general, 5 Clearing, 61 Cleveland, Akron & Columbus Ry., 61 Cluster-bent trestles, 42 Combustible matter, 55 Compound timber trestles, 40 Construction records. 72 Corbels, 31 Cost, annual, 2 Cost of embankment, 3 Cost to height, 5 Cost of trestles, 5 Counter-posts, 39 Countersunk bolts, 49 Cram's pile-hammer, 19-23 Creosoted trestles, 64 Crib foundations, 26 Cross-cut saw, 58 Curves, trestles on, 42, 63 Cut spikes, 45 Cutting off piles, 11, 12 Damages, 66 Defective work, 66 Delaware & Hudson Canal Co.. 30, 31 Delays, 66 Denver, & Rio Grande R. R.. I, 86 Denver, Texas & Fort Worth R. R., 33 157 '58 INDEX. Design, 5 Dimensions, 62 of stringers, 34 Distribution of trc-stles, 2 Division estimate, 75 Double-track trestles, 43 Dowels, 48 Dowel-joints, 30 Drawings, 62 Drift-bolts, 46, 47, 48 Drift-bolt joints, 30 Drip-holes, 27 Drivers, pile, 13 Driving piles, 9 " " , method of, 13 Dry stone foundations, 27 Durability of piles, 6 Economy of trestles, 4 Elevating rails, 42, 43 Embankment, 3 , connection with, 52 " , cost of, 4 Ends of guard-rails, 37 Engineer, 67 Engineering, field, 56 Erecting, 57 Esquimalt & Nanaimo Ry., 154 Estimate, 75 Expenditures, annual, 2 Extra work, 66 Fastening floors, 38 stringers, 34 Field-engineering, 56 Fire-protection, 5, 54, 65 Floor-fastening, 38 Floor-systems, 35, 36 Floors, solid, 43 Florence R. R., 61 Framed bents, 24 " trestles, 5 Framing, 63 French Broad Valley R. R., 61 Foot-walks, 54 Force accounts, 67 Fort Worth & Denver City Ry., 128 Foundations, classification, 24 , crib, 26 , dry stone, 27 , grillage, 25, 26 , masonry, 24 , mud-sill, 25 , pile, 24, 25 , solid rock, 26, 27 , sub-sill, 25 Georgia Pacific Ry., 33, 61, 124 Grillage foundations, 25, 26 Grip, 49 Guard-rails, 35 , ends, 37 Guard-rails, inside, 37 , joints, 37 Guards, rerailing, 53 Gulf, Colorado & Santa Fe R. R., 33, 61 Hammer, 58 Hammer, pile-driver, 9 Hand-car refuge-bay, 54 Hand-saw, 58 Hatchet, 59 Height of bent, 30 High trestles, classification, 40 Highways, 65 Hoisting-machines, 60 Holes, drip, 27 Information, 67 Inside guard-rails, 37 Inspection, 4, 65, 77, 78 " , Burlington, Cedar Rapids & Northern R. R., 82 Inspection Erie Ry.,8o Plant System, 80 records, 79 Intercolonial Ry., 150 Iron, specifications for wrought-, 64 " cast-, 65 Iron, weight of bar, 48 Item sheet, 74, 75 Jack-stringer, 34 Joint-plate, 30 Joints, 29 " , dowel, 30 " , drift-bolt, 30 " , guard-rail, 37 " , plaster, 30 " , preservation of, 61, 63 " , stringer, 33 Kansas City, Fort Scott & Memphis R. R., 36 Kewaunee, Green Bay & Western R. R., 140 Knee-braced trestles, 43 Labor, 65 Lag-screws, 49 Lateral bracing, 40 Length batter-posts, 28 Life, 2, 4 Liquors, intoxicating, 66 Literature, 4 Log- hook, 60 Log-wheels, 60 Longitudinal bracing, 39 Louisville & Nashville R. R., i, 31, 36, 43, 98,112 Maintenance, 2 Mallet, 58 Masonry foundations, 24, 73 Material, 65, 70 Mathematics, 5 Matter, combustible, 55 Maul, spike, 58 Milwaukee & Northern R. R., 140 Minneapolis & St. Louis Ry., 94, 122 INDEX. Missouri, Kansas & Texas Ry., 36 Missouri Pacific R. R., i, 15 Mud-sill, 25 Nails, 45 New Orleans & Northeastern R. R., 61 New York Central R. R., i New York, Lake Erie & Western R. R., i, 30, 31, 80 New York, New Haven & Hartford R. R., 25 New York, Ontario & Western R. R., 24 New York, Providence & Boston R. R., 33, 148 New York, West Shore & Buffalo R. R., 36, 37 New York, Woodhaven & Rockaway R. R., 31, 146 Norfolk & Western R. R., 1 1, 26, 42, 43, 72, 108- 1 1 1 Northern Pacific R. R.,9, 10 Notching, 30 Numbers, bridge, 83 Nut-locks, 51 Ohio Connecting Ry., 31, 61, 116 Oregon & Washington Territory R. R., 126 Oregon Pacific R. R., 33, 114 Packing blocks, 32 " washers, 50 Payment, 68 Peavey, 60 Pennsylvania R. R., 33, 34, 36, 37, 39, 104 Pile, batter, 7 " bents, 6 " caps, 12 " drivers, 13 " , car, 15-19 " , scow, 13-15 " , simple, 13 " driving, 9, 10 " " methods, 13 " record, 10 " foundations, 24, 25 " hammer, steam, 19-23 Pile-point, 8 " ring, 9 " shoes, 8, 9 " trestles, 5 Piles, 62 " , cutting off, 1 1, 12 " , durability, 6 " , length, 9 " , size, 6 " , spacing, 6, 7 " , specifications, 6 " , splicing, 8 " , test, 9, 10 Plaster-joint. 30 Plate-joint, 30 Plumb-posts, 28 Point, pile, 8 Pontiac, Oxford & Port Austria R. R., 35 Posts, 28 " , batter, 28 " , counter, 39 " , plumb, 28 Poughkeepsie Bridge, 8 Premium, 83 Preservation of joints, 61, 63 Price, 68 Prices of trestle-material, u Proposal, 68 Protection against fire, 54 Quantities, 67 Queen & Crescent System, i Rails, elevating, 42, 43 " , guard, 35 " , inside guard, 37 Rate of pile-driving, 10 " trestling, i Records, construction, 72 Refuge-bay, 54 Relative cost, 4 Repair, 4 Repairs, annual cost, 2 Replaceable trestle, 2, 3 Report, track-walker's, 77 Rerailing, 5 guards, 53 Richmond & Danville R. R., 37, 130 Ring, pile, 9 Risks, 65 Roads, 65 Round-timber trestles, 43 Rules, 59 St. Louis & San Francisco R. R., i St. Paul, Minneapolis & Manitoba R. R., 33, 36, 61, 142-145 San Francisco & North Pacific R. R., 33, 35, 106 Savannah, Florida & Western R. R., 30, 54 Saw-mill, 60 Saws, 58 Scow pile-driver, 13-15 Screws, lag, 49 Separators, 32, 50 Shenandoah Valley R. R., 31 Ship-augers, 59 Shoes, 8, 9 Sills, 27 " , bank, 52 Solid rock foundations, 26, 27 Spacing bents, 30 " piles, 6, 7 Specifications, standard, 61 Spike-maul, 58 Spikes, boat, 45, 46 " , cut, 45 Splicing piles, 8 Split caps, u, 30 Square, 59 Staking out, 56 Standard design, 5 " specifications, 61 Steam pile-hammer, 19-23 Stone foundations, 27 i6o INDEX. Stringer-joints, 33 Stringers, 32 " , dimensions, 34 , fastening, 34 , jack, 34 " , Pennsylvania R. R., 34 " , trussing, 35 Sub-sill foundation, 25 Sway-bracing, 39 Technical terms, ix Template, batter-post, 29 Tenon, 12, 29 Terms, ix Test-piles, 9 Test-pile record, 10 Texas & Pacific Ry., 36, 51 Thimbles, 50 Ties, 35 Timber, measurement, 71 , quality, 62 Toledo & Ohio Central R. R., 40 Toledo, St. Louis & Kansas City R. R., 36, 37,88, 137 Tools, 29, 58 " for repair, 83 Track-walker's report, 77 Trains, 65 Trenail, 12 Trespass, 66 Trestle material, n Trestles, classification, 40 " , cluster-bent, 41 " , compound timber, 40 " , cost, 4 " , creosoted, 64 " , curved, 42, 63 Trestles, distribution, 2 " , double-track, 43 " , economy, 4 " , framed, 5 " , knee-braced, 43 " . pile, 5 " , replaceable, 23 " , round timber. 43 " , solid floor, 43 " vs. iron bridges, 4 " vs. embankment, 4 Trestling, amount, i Trussing stringers, 35 Union Pacific R. R., i Values, capitalized, 2, 3 Vancouver, Klickitat & Yakima R. R., u Vicksburg & Meridian R. R., 61 Vicksburg, Shreveport & Pacific R. R,, 61 Wabash R. R., i Walks, foot-, 54 Washers, cast-iron, 50, 51 " , packing, 50 " , wrought-iron, 50, 51 Weight of bar-iron, 48 " " bolts, 49 " " drift-bolts, 46 Wheels, log, 60 Wisconsin Central R. R., 33 Wrenches, 60 Wrought-iron, specifications, 64 " washers, 50, 51 Work,, defective, 66 " , extra, 66 ' " , preservation of, 67 THZS DATE AN INITIAL FINE OF 25 CENTS ASSESSED FOR FAILURE TO RETURN BOOK ON THE DATE DUE THE PENALTV RETURN TO the circulation desk of any University of California Library or to the NORTHERN REGIONAL LIBRARY FACILITY Bldg. 400, Richmond Field Station University of California Richmond, CA 94804-4698 ALL BOOKS MAY BE RECALLED AFTER 7 DAYS 2-month loans may be renewed by calling (510)642-6753 1-year loans may be recharged by bringing books to NRLF Renewals and recharges may be made 4 days prior to due date DUE AS STAMPED BELOW 51 7 MAY 5 m 15M 4-02