A new species of railway, possessing many advantages peculiar to itself, was invented and patented in the year 1821 by the late Mr. H. R. Palmer, who was for some years engineer to the London Dock Company. Instead of two lines of rail laid upon the ground, as heretofore, Mr. Palmer's railway consists of only one, which is elevated upon pillars, and carried in a straight line across the country, however undulating and rugged, over hills, valleys, brooks, and vol.. II.
3d livers, the pillars being longer or shorter, to suit the height of the rail above the surface of the ground, so as to preserve the line of the rail always straight, whether the plane be horizontal or inclined. The waggons, or receptacles for the goods, travel in pairs, one of a pair being suspended on one side of the rail, and the other on the opposite side, like panniers from the back of a horse. By this arrangement only two wheels are employed, instead of eight, to convey a pair of waggons; these two wheels are placed one before the other on the rail, and the axle-trees upon which they revolve are made of sufficient length and strength to form extended arms of support, to which are suspended the waggons or receptacles on each side of the rail, the centre of gravity being always below the surface of the rail. The rods by which the waggons are suspended are inflexible; hence, although the weights on each side be not equal, they will, nevertheless, be in equilibrio; as may be observed in a ship, which, being unequally loaded, assumes such an angle with the surface as preserves the equilibrium. Although an equal distribution of the load on both sides is desirable, it is not necessary.
A number of carriages are linked together, and towed along the rail by a horse, as barges on a canal. Owing to the undulation of the country, the horse will sometimes be much below the rail, in consequence of which he is provided with a sufficient length of rope to preserve a proper angle of draught.
Fig. 1 is an end view of the carriage, with a cross section of the rail, and a pillar, showing its form, and manner of fixing.
Fig. 2 is a side view of the railway passing over an uneven surface, with three of the supporting pillars of unequal length. Upon the upper surface of the rail are seen the two carriage-wheels, and the manner of suspending the waggons or receptacles from the axle-trees, which is, however, better shown by Fig. 1, letters I I I I.
Fig. 3 is a plan of the same, which exhibits the comparative measurements, and the mode by which the receptacles are braced together. The same letters of reference refer to the same parts in the different figures. A, Fig. 1, represents an upright pillar of cast iron, having, at the shoulder, a flange, which rests upon the surface of the ground. The pillar is formed with ribs at right angles, which converge towards the lower extremity, and are notched in the edges, for the better securing it firmly in the ground. The hole in which it is to be inserted is to be previously well rammed, by a kind of pile-driving engine, and the foot of the pillar surrounded with hard materials, which are also to be rendered as compact as possible. Three of these pillars are shown fixed in Fig. 2, placed about nine feet apart. At the upper extremities of the pillars are long clefts or openings, to receive the rail B, which is composed of deal planks, set on their edges, with their upper surface D defended by cast or wrought iron plates, a little convex on the upper side. When the rail has been some time in use, and all has taken a bearing, a little adjustment of the line may be requisite before the rail is bolted to the pillars; to effect which, a very simple and easy method is provided.
In the cleft of the pillars, and under the rail, two wedges a a are introduced in opposite directions, whereby its level may be adjusted with the nicest accuracy. The wheels D D are provided with flanges, to keep them on the rail, and their peripheries are slightly concave, to adapt their surfaces to that of the rails. E E are the arms or axles; H H are the receptacles for the goods, which are made of plate iron, and are suspended to the arms, as before mentioned, by the inflexible rods I I I I. To one of the arms a chain K is hooked, to which a towing-rope may be connected. Any number of carriages may then be attached together by chains hooked on to the angles.
The annexed Fig. 4 is intended to exhibit a portion of the railway in use, and the methods by which several of the obstacles which frequently present themselves are overcome. On the left is seen a jointed rail, or gate, that crosses the road over which the carriages have just passed, and the gate swung back, to leave the road open; the horse and man having just forded, the train of carriages is proceeding in its course, and following another train, part of which is seen on the right, crossing a rail bridge, simply constructed for that purpose.
Provision is made for trains of carriages that are proceeding in opposite directions, by means of "sidings" or passing places. With respect to loading, if both receptacles be not loaded at the same time, that which is loaded first must be supported until the second is full. Where there is a permanent loading-place, the carriage is brought over a step or block; but when it is loaded promiscuously, it is provided with a support connected to it, which is turned up when not-in use. From the small height of the carriage, the loading of those articles usually done by hand becomes less laborious. The unloading may be done in various ways, according to the substance to be discharged, the receptacles being made to open either at the bottom, the ends, or the sides. In some cases it may be desirable to suspend them by their ends, when, turning on their own centres, they are easily discharged sideways.