Stone &Worts for blocks, on which the rail was car ried by means of a chair (pi. 24, fig. 14) of varying pattern, according to the form of the rail, were used in the early days Of the railroad in England and elsewhere, but soon fell into disfavor among engineers because of the difficulty experienced in fastening the rail-clmirs; furthermore, they proved to be too solid and unyielding, causing rough riding, and consequently were objected to by the travelling public. Latterly, however, their use has been revived on the I3avarian State road, the Taunus road, and others. These blocks, about 2 feet square on the surfaces, are roughly-liewn cubes of hard rock (granite, sandstone, etc.), laid in a bed of well-consolidated materials, and not in freshly-made embankments. The rail is fastened down either by spikes driven into a wooden plug in the stone or by screw bolts passing entirely through the block. A strip of asphaltum felt is placed between the base of the rail and the block (fig. 22), giving a some what yielding bearing and serving by its elasticity to counteract the jar ring of the train, which otherwise would be serious. To prevent the spreading of the rails, especially on curves, extra cross-sills are introduced at the rail-joints.
Metallic .57cepers.—In place of stone blocks metallic sleepers have come into vogue extensively in tropical countries (Egypt, Algeria, India), and to some extent, also, iu France and Germany. One of the best-known and most practical forms of the metallic permanent way is the system of Greaves (fig. 23), introduced in 1846. The rail-support in this plan consists of a pot- or bowl-shaped cast-iron sleeper having cast on its summit the chair to which the rail is secured. To give the system the requisite strength and to hold the track to gauge, every alternate pair of sleepers is firmly united by transverse tie-bars of iron, which pass through and are bolted or otherwise fastened to them. In the tops of the sleepers are holes through which the material for packing may be introduced and tamped with a suit able rammer. Griffin has improved this plan of sleeper by casting it so as to give a larger bearing-surface for the rail, and by casting ribs upon it to give it greater streng-th (South America).
Ili-ought-4nm made of wrought-iron were first introduced in Belgium in 1862, and found their way into France and Portugal, and afterward into Germany. The oldest (Belgian) form has a horizontal I-shaped section (fig. 29) with oaken blocks as the support and for the attachment of the rails. In Germany the most successful system of this order is that of Vautherin, first introduced upon the Lyons Railway, in France, in 1864. This cross-tie has a section like the letter A with the upper or triangular portion cut away. It is exhibited in Figure 3oc.
The section of the Vantherin sleeper gives great stiffness, so that even when it is not well packed breakages rarely occur, and the sleepers are not liable to displacement on curves. Figure 3ob (fil. 24) illustrates the mode of fastening the rail to the Vantherin sleeper. To give the rails the neces sary inclination, the tie is made slightly curved (fig.. 3oa). The Vautherin tie appears to have made an excellent record in service. It is not adapted to a road-bed with broken-stone or slag ballast, but on a roadway ballasted with gravel it answers its purpose admirably. It is reported that, while its cost is no greater than that of an oaken sleeper, it will outwear three of the latter.
Steel made of Bessemer steel have also been pro posed and experimentally introduced. The Boston and Maine Railroad, in the United States, introduced ties of this material in t885 on a sec tion of its road near Boston where they would be subjected to very heavy traffic. They apparently have given entire satisfaction. Some years ago, Sir William Siemens, in England, proposed the use of glass for this purpose; but there is no evidence that the suggestion was ever put in practice.
Aida/11c PC1-1111711elli Way.—While experiments looking to the substitu tion of Cross-ties of iron for those of wood were being made elsewhere, the engineers of the German railways were striving to develop the longitudinal permanent way in metal, the object of their efforts being to produce a rail which when laid directly upon the road-bed should have sufficient rigidity to support the traffic-load without displacement. A rail of this descrip tion (fig. 24) was proposed in England in 1849 by Barlow, but did not prove successful in practice. The system of Hartwich embodies the same principle. In this, the rail has a broad, flat base, which rests in and is bolted to a metallic base-plate, and the adjoining rails are secured to one another by means of a fish-plate union. The gauge of the way is maintained by transverse tie-bars at suitable distances apart. The Hartwich iron way appears to have met with more favor in Germany than elsewhere. Figures 25a–c shows a section of the road-bed prepared to receive this rail, and the mode of fastening- and joining- the rail.
Hill's Metallic II'av.—While in the Hartwich system the rail and its longitudinal sleeper are united in a single piece, the Hilf metallic perma nent way, another German system, is formed of two parts—namely, a rolled longitudinal sleeper of peculiar form and a comparatively light flange-rail of steel. The cross-section of the sleeper resembles the letter E with angles bevelled and laid face down, so as to present a flat upper surface, to which the rail is secured by bolts and nuts. The adjoining rails are united bv fish-plate connections, and the gange is preserved by means of transverse tie-rods secured at both ends with nuts. One of these tie-rods is used for each length of rail (3o feet). The Hilf system is very well spoken of as being simple, cheap, easily laid and maintained, and has shown good endurance in service. It has given excellent results on the Nassau (Ger man) railways. A cross-section of the road-bed with Hilf's system, and a rail-section exhibiting- the mode of fastening employed, are seen on Plate 24 (jigs. 26a, b).
Schiffier's Aleta head of the rail is the portion that suf fers the most from wear: the web and base remain in good serviceable con dition, while the head may be so badly worn away as to be unserviceable. Taking advantage of this fact, the German engineer Schitiler of Brunswick devised a metallic permanent way in which the rail-head is made of cast steel and so arranged as to be removable and replaceable. Figure 28 shows a section of the Schiffler permanent way, in which the rail-head of steel is seen attached by bolts and nuts to a longitudinal sleeper formed of two angle-irons. An iron reinforcing- plate is introduced below the rails at joints, and the gauge is preserved by the use of transverse tie-rods or strips. A plan similar in general principle to the foregoing was employed in the construction of the Hanover State Railway. It is exhibited in section in Figure 27. The longitudinal sleeper forming the rail support and base consists, in this ease, of two obtuse-angled plates of rolled iron, between which the rail-head is secured by bolts and nuts in the usual way. The gauge is preserved by transverse plates of flanged iron, and, to strengthen the sub-rail to resist long,itudinal displacement, saddles of T-iron bent to proper shape are riveted to the under side of the sub-rail at inter vals, as seen in the sketch.
Composite rails of the kind just described present difficulties in laying with accuracy and maintaining in alignment, especially on curves. Indeed, taking the experience gained with the entire system of metallic permanent way, of which many forms have been proposed and experiment ally tested in addition to those herein described, it would be unsafe to say more than that it has been demonstrated that iron may be substituted in place of timber for roadway sleepers.