have been devised to avoid the frequent accidents caused by misplaced switches. These are so contrived that trains will be able to pass them safely even if they are misplaced. Such is the Wharton Safety switch (pl. 25, fig. 4), used npon the Pennsylvania and other roads in the United States. In the case of stub-switches, safety-castings are sometimes provided, which are bolted to their sides, and which, in the event of mis placement of the switch, receive the flanges of the wheels of a train and guide them safely to the switch-rails. Safety devices in connection with switches are of no avail when the moving train faces the switch, seeing that in such case it must go the way the switch is set, whether right or wrong. Various forms of switches and their attachments are shown on Plate 24 (figs. —The throwing of the points of the switch is effected by means of a lever pivoted in a cast-iron frame—the "switch-stand." The lower end of the lever is suitably attached to the connecting-bar joining the movable ends of the switch-rails (fig. 31). Provision is made for securely locking the lever' when it is set either way, and frequently a counterweight is attached to its free end, to assist in bringing it to its proper place. The upright stand commonly used is shown on Plate 25 (fig. 13). The stand is provided usually with two notches, to one or the other of which the lever may be secured by some convenient locking device. Where, as in the case of stub-switches, it may be necessary to have three throws, three notches are arranged accordingly. The top of the switch-lever is usually furnished with a target, which enables the engine driver readily to observe which way the switch is set. The " ground lever " or " tumbling-lever " stand is largely used in the United States. In this form the lever lies upon the ground in whatever position the switch may be set. It is convenient, as it occupies very little space. A colored target or a lantern may be connected with this, as with the other form, to indicate to the engine-driver the position of the switch.
would obviously be very inconvenient, were it neces sary, to conduct all the movements of trains and locomotives solely with the aid of switches, and this inconvenience would be felt especially at important stations. For the manipulation of entire trains with the loco motive, the switch and the turnout afford the only serviceable method; but for the more rapid transfer of rolling-stock, especially of single locomotives and cars, from one track to another, or into round-houses, shops, etc., other appliances are usecl, by which a sudden change or complete reversal of direction may be made. These movements are effected by turntables (pt. 28, fig. 13; pi. 3r, fig. I), or, where a lateral movement only is called for, by a travelling platform such as that shown on Plate 28 (fig. 14).
The turntables now in universal use in railroad shops and yards, and at all important stations, consist of a platform to which, by suitable mechanical artifices, motion can be imparted in a horizontal plane. The top of the platform carries one or several tracks of rails. The platform is rotated about a central pivot and at the outer end carries rollers, on which it turns, the rollers running upon a circular track. 'file turntable is made long enough (from 4o to 6o feet) to accommodate a locomotive with its tender. The frame is either of wood (where it is housed) or of cast or wrought iron. The table is usually placed in a masonry-lined pit so adjusted in respect to heig,lit that the tracks it carries on the platform shall be on a level with that of the rails of the tracks with which it is intended to make connec tion. The platform is made occasionally in the form of a cross, providing
for two tracks at right angles to each other, or, for greater convenience, it may cover the whole of the pit and carry a number of radiating tracks. To reduce the friction as inuch as possible, the centre-bearing is provided with anti-friction rollers or equivalent devices. Adams's (English) turn table, referred to by Knig-lit, floats in a water-tank. The turntable is moved either by a lever or by wheel-work, or occasionally, where it is in constant use, by a small steam-engine carried on the platform. A cross section of the form of turntable largely used in the United States is shown on Plate 31 (fig. 1).
The (pl. 2S, jig. 14) consists of a section of track sup ported on a suitable carriage. The carriage is moved forward and back ward on a depressed track at right angles to the track-rails with which connection is to be made, so that the track on the platform carrying the locomotive or car may be aligned with any set of them to which it is desired to transfer it. The Figure exhibits the construction of one of these transfer-tables, and the mechanism by which it is actuated.
value of narrow-gauge railroads as feed ers depends much upon the facilities for handling- through freight with economy and despatch. By means of the Ramsey car-transfer apparatus, the cars of the standard gauge can be transferred to the narrow gauge with out breaking- bulk. BV this device, the trucks under the cars are removed expeditiously and easily, and others are substituted which are adapted to the gauge to which it may be necessary to change.
The means employed to effect this change of trucks consists of a depressed portion of the main tracks of the roads of both gauges laid par allel one within the other (pl. 3i,figs. 12-14), with other tracks of the grade of the main line at the sides of this depressed portion, extending somewhat beyond both ends of the incline entering the depressed portion of the track (fig. 13). Upon these side-tracks are fitted wheeled trucks, which, being placed at the sides of a car before entering the incline, and hav ing beams or bars placed across them under the body of the car (Ar. 12), carry the car-bodv at the grade of the road, supported upon the side-truck and tracks, while the truck of the car descending the incline is diseng-aged and remains in the depressed portion (fig. 13). As the car progresses, the king bolts engage with trucks previously placed on the depressed track and having- wheels of the other gauge, and these trucks, rising on the other incline, receive the weight of the car-body and permit the withdrawal of the beams. The temporary supporting-trucks are tlins disengaged, leaving the car ready to run upon the road of another gauge.
I3y the simple artifice of effecting- this transfer upon side-tracks laid with a sufficient gradient to supply propelling-power adequate to carry the cars by gravity over the depressed portion of the track and to lift the new set of trucks upon the incline to the road of differing gauge, the necessity for the application of motive-power in effecting the transfer is obviated. This system of transferring cars has proved of great value in the railway service of the United States (where until recently divergencies of gauge were very numerous) in saving time, labor, and expense.