Page:Encyclopædia Britannica, Ninth Edition, v. 20.djvu/260

Rh 242 RAILWAY Fish- temperatures, to allow for expansion in hot weather. The joints plates, of the rails are united or fished with parallel steel plates lodged within the side channels of the rails and fastened with four bolts and nuts passed through the web of the rails, and, in order that the fish-plates may take a solid and steady bearing, the entering faces of the upper and lower members of the rails are in most in- stances formed straight and steep, at an angle of about 2 to 1. For the same purpose the fish-plates are hollow at their inner faces, so as not to be in contact with the vertical members or web of the rails, and are slightly elastic in consequence. Vertical stiffness, also, is of prime importance in fish-plates, which act as beams fixed at the ends and uniformly loaded, being required to sustain the loads of trains passing over the joints. On some lines, accordingly, the fish-plates are made of greater depth, extending downwards along the lower table of the rail, and are even turned under it, Sleepers, whence they are called clip fish-plates. The chairs are laid on transverse timber sleepers, ordinarily cut from Baltic redwood to a scantling of 10 inches wide and 5 deep, and 9 feet in length, speaking precisely, only 8 feet 11 inches in length, to secure the timber from import duty. They are most commonly submitted to a preserving process by the injection of about 2^ gallons of creasote into each sleeper. The chairs are fixed to the sleepers by iron spikes or oak trenails, or both, varying in number from two on the lines of lighter traffic to three or four on lines of heavier traffic. On the London and South -Western Railway and on the South - Eastern Railway a compound fastener is used, a spike driven into a hollow trenail, after the latter is driven into the sleeper. There are usually eleven cross sleepers to each length of rails of 30 feet, making the average distance between the sleepers about 2 feet 9 inches from centre to centre. It is usual to space them apart more widely in the middle portion of the rail-bars (up to 3 feet) and more closely about the joints, with a view to equalizing the vertical resistance of the rails to rolling loads, by supplying a greater degree of support from the sleepers near the joints. The standard models of permanent way on the double-headed rail and chair system adopted by Mr John Fowler for the New South Wales railways have been already noticed. The rails are shown in section in figs. 29 and 35. The sleepers are of colonial hard woods, chiefly iron-bark timber. They are laid 2 feet 6 inches apart between centres at the joints of the rails, and 3 feet 1 inch apart elsewhere. The upper and lower tables of the rails are curved or rounded in section to a radius of 5J inches, the height of the rail. The entering or overhanging faces of the rail are inclined at Fig. 29. Fig. 30. FIG. 29.- Double-headed rail ; New South Wales Railway. Fio. 30. -Chair ; New South Wales Railway. a slope of about 1 in 2, forming straight and equally inclined bearings to receive the fish-plates. The rails, while in course of manufacture, are tested by selecting a few rails of each day's make, from which a portion 4} feet in length is cut off and placed on iron supports 3$ feet apart, and is subjected to three blows from a weight of 1 ton falling 12 feet each time. The rails are to deflect not less than 6 inches and not more than 7$ under this test without showing any signs of fracture. The fish-bolts, as well as the spikes for fastening the chairs to the sleepers, are made of the finest quality of close fibrous iron. Fifty per cent, of the rails were ordered 24 feet in length, 40 per cent. 21, and 10 l>er cent. 18. The chairs (fig. 30) are 13 inches long at the sole, 4$ wide, and 1 thick at the seat of the rail. Test bars of the metal used for the chairs are cast to a scantling of 2 inches by 1 inch and 3J feet long. They are placed on edge, on supports 3 feet apart, and are required to sustain a dead load of 30 cwt. suspended from the centre of the bar without fracture. The spikes are seven-eighths of an inch in diameter, tapered at the head to fifteen-sixteenths, with hemispherical or cup -heads forged from the solid bar. The above-described way, as laid in New South Wales, is bedded in bal- last consisting of broken stone 12 inches in depth below the sleepers, broken to a gauge of 3 inches, boxed up with broken stone of a smaller size to a gauge of 2 inches for a depth of 8 inches. The total depth of the ballast from the crown of the formation is 22 inches. The surface of the formation below the ballast is rounded in cross-section, in order to drain off such water as penetrates through the bal- last. Grips or furrows are cut and drains laid in where necessary, so that no water is allowed to remain on the line or under the ballast. The South-Eastern double-headed rail (fig. 31) is keyed into chairs 4^ inches wide and 13| long at the sole. They are fixed to the sleeper by two spikes driven into two hollow oak trenails. The sleepers at the joints are laid 2 feet 4 inches apart between centres. * IG - 31 - ' ril suth Railway. The following are the quantities of material for 1 mile of way, single line : tons. cwt. qr. Steel rails, 82 ft) per yard 3521 yards 128 17 3 Fish-plates 505 pairs 5 01 Fish bolts and nuts 2020 122 Chairs 4022 56 11 Chair spikes 8044 3 11 3 Keys 4022 Sleepers, creasoted 2011 Trenails 8044 These quantities are considerably less than those of the Midland Railway (which are stated below), as may naturally be the case for a line chiefly of passenger traffic in comparison with one of heavy goods and mineral traffic. The double-headed rails of the North- Eastern Railway, 82 ft per yard, are bedded on blocks or cushions of oak placed in the bottom of the chairs, the advantages of which have already been noticed. The type section of way of the Midland Railway is shown in fig. Bull- 32. The formation is inclined each way from the centre, making headed two straight slopes for drainage. The ballast is of strong gravel rails, { ! i ! f 1 i Fio. 32. Type section of way of Midland Railway. broken stone, and ashes or clinker, chiefly gravel. It covers a width of 26 feet for two lines of way. It is laid to a depth of 16 inches at the middle of the six-foot, and is formed level with the upper sides of the sleepers between the rails in the four-foot, with a medium depth of 16 inches, or 11 inches beneath the sleepers. At the outer sides of the rails the ballast is heaped level with the tops of the chairs, or, more precisely, the tops of the keys, and is sloped down to the formation at each outer side. The upper and lower surfaces of the rail (see fig. 33) are curved to a radius equal to the height of it, and the planks are flat, adapted for taking up lateral blows and mitigating wear. ' The chairs are remarkable for large dimensions, being 7 inches wide and 15 long at the sole, which is 1 inches thick under the rail, and for their weight, 50 Ib each. The cost of relaying 1 mile of single way on the Midland system just described, based on contract prices in 1884, amounts to 1572, 8s. 5d. Deduct-. ing credit for old material to the amount of 714, 8s. 3d., the net cost of relaying is 858, Os. 2d. The particulars of quantities, cost, and credit are given in the following statement, prepared by Mr Alfred A. Lang- ley, the engineer of the railway : Cost to relay 1 mile of Single Line with 30-fect Bull-headed Steel Rails, weighing 85 Ib. per yard ; eleven Sleepers to each 30 feet length. Steel rails, 3520 yards at 85 Ib = 133 J tons, at 5 667 10 Chairs, 3872 at 50 tt> = 86$ tons, at 3 20910 Fish-plates (steel clip), 352 pairs at 40 lb= 6J tons, at 8 50 Bolts and nuts, 1408 at 1* tb=l ton, at 9, 10s 9 10 Spikes, 7744, at 11 tb = 4J tons, at 7, 10s 3117 6 Trenails (solid oak), 7744, at 2, 10s. per thousand 19 7 2 Keys (oak), 3872, at 4 per thousand 15 9 9 Sleepers (creasoted), 1936, at 4s 387 4 Labour, 1760 yards, at Is. 6d 132 Total cost of laying 1572 8 5