[Fig. 366] illustrates a method of bringing the UP and down lines of a double line of railway close to each other, and passing them over a single-line opening bridge, or a bridge where the works for the second line have not been completed. This arrangement avoids the necessity of any switches, and prevents any accidents which would arise from a misplaced switch. Each set of trains is effectually kept to its own line of rails. With proper signalling or pilot working, the double-line traffic can be worked over the single-line bridge without difficulty. The writer has adopted the above arrangement in many cases when renewing double-line bridges or viaducts where the width for traffic working has been restricted to half of the bridge.
In some instances the same system has been extended to the
carrying of four lines of rails over a double-line bridge, as shown on [Fig. 367].
The principal tool used by platelayers for lifting the permanent way is a long iron-shod wooden lever, as shown in [Fig. 368]. The point of the lower end is pushed under the sleeper, and the curved shoulder placed on a large stone or piece of wood as a support, and then by pulling down the upper end of the lever the road can be lifted to the height required. Screw lifting-jacks of various kinds are also used for the same purpose, the foot or base of the jack resting on the ballast, while the claws grasp the under side of the rail, and raise it by means of the screw. With appliances which lift by the rails, the sleepers have to be raised by the holding power of the spikes or bolts, an operation which is apt to throw undue strain on spikes. Where possible it is preferable to lift from the under side of the sleepers.
Beaters similar to the one shown on [Fig. 369] are used for packing the ballast. One end of the beater is pointed like a pick, and serves to loosen the ballast or broken stone, and the other end is made somewhat in the hammer-head form to pack or beat the ballast under the sleeper. With skilled men the beater is a most useful tool, speedy and effective in its action. Held in both hands, it is raised slightly, and then brought down sharply, the hammer-head striking the gravel or broken stone placed alongside for packing under the sleeper. A series of smart blows can be given with rapidity and without requiring any great muscular effort. In some foreign countries there is difficulty in initiating the natives to work with the ordinary beater, on account of the stooping position necessary for its use. To meet this difficulty the writer has in many cases substituted a packing or tamping bar, as shown in [Fig. 370]. This bar, about 5 feet long, is made of light round wrought-iron or steel, with a ring-shaped handle at one end, and an ordinary beater head at the other. The workman using this bar stands upright, guides the bar, held loosely, with his left hand, and with his right gives a continuance of smart blows. This tool works well in the hands of light active natives, who can thus give a number of rapid strokes without much exertion.
The simple rail-bender, or Jim Crow, of the form shown in [Fig. 371], is much used by platelayers for giving a slight bend or set to rails which have to be laid down on sharp curves on main line or cross-over roads. The rail is laid across the two arms,