THE GIRARD HYDRAULIC RAILWAY

Scientific American Supplement, No. 717, September 28, 1889, by Various, is part of the HackerNoon Books Series. You can jump to any chapter in this book here. THE GIRARD HYDRAULIC RAILWAY

THE GIRARD HYDRAULIC RAILWAY.

We give herewith some illustrations of this railway which has recently excited so much technical interest in Europe and America, and which threatens to revolutionize both the method and velocity of traveling, if only the initial expense of laying the line can be brought within moderate limits. A short line of railway has been laid in Paris, and we have there examined it, and traveled over the line more than once; so that we can testify to the smoothness and ease of the motion. Sir Edward Watkin examined the railway recently, and we understand that a line two miles long is to be laid in London, under his auspices. He seems to think it might be used for the Channel tunnel, being both smokeless and noiseless. It might also, if it could be laid at a sufficiently low price, be useful for the underground railways in London, of one of which he is chairman. We are favorably impressed by the experiments we have witnessed; our misgivings are as to the cost. The railway is the invention of the well known hydraulic engineer, Monsieur Girard, who, as early as 1852, endeavored to replace the ordinary steam traction on railways by hydraulic propulsion, and in 1854 sought to diminish the resistance to the movement of the wagons by removing the wheels, and causing them to slide on broad rails. In order to test the invention, Mons. Girard demanded, and at the end of 1869 obtained, a concession for a short line from Paris to Argenteuil, starting in front of the Palais de l'Industrie, passing by Le Champ de Courses de Longchamps, and crossing the Seine at Suresnes. Unfortunately, the war of 1870-71 intervened, during which the works were destroyed and Mons. Girard was killed. After his death the invention was neglected for some years. A short time ago, however, one of his former colleagues, Mons. Barre, purchased the plans and drawings of Mons. Girard from his family, and having developed the invention, and taken out new patents, formed a company to work them. The invention may be divided into two parts, which are distinct, the first relating to the mode of supporting the carriages and the second to their propulsion. Each carriage is carried by four or six shoes, shown in Figs. 3, 4, and 5; and these shoes slide on a broad, flat rail, 8 in. or 10 in. wide. The rail and shoe are shown in section in Fig. 1. The rail is bolted to longitudinal wooden sleepers, and the shoe is held on the rail by four pieces of metal, A, two on each side, which project slightly below the top of the rail. The bottom of the shoe which is in contact with the rail is grooved or channeled, so as to hold the water and keep a film between each shoe and the rail. The carriage is supported by vertical rods, which fit one into each shoe, a hole being formed for that purpose; and the point of support being very low, and quite close to the rail, great stability is insured. It is proposed to make the rail of the form shown in Fig. 2 in future, as this will avoid the plates, A, and the flanges, B, will help to keep the water on the rail. Figs. 3, 4, and 5 show the shoe in detail. Fig. 3 gives a longitudinal section, Fig. 4 is a plan, and Fig. 5 is a plan of the shoe inverted, showing the grooves in its face. Fig. 3 shows the hollow shoe, into which water at a pressure of ten atmospheres is forced by a pipe from a tank on the tender. The water enters by the pipe, C, and fills the whole of the chamber, D. The water attempts to escape, and in doing so lifts the shoe slightly, thus filling the first groove of the chamber. The pressure again lifts the shoe, and the second chamber is filled; and so on, until ultimately the water escapes at the ends, E, and sides, F. Thus a film of water is kept between the shoe and the rail, and on this film the carriage is said to float. The water runs away into the channels, H H (Fig. 6), and is collected to be used over again. Fig. 3 also shows the means of supporting the carriage on the shoe by means of K, the point of support being very low. The system of grooves on the lower face of the shoe is shown in Fig. 5. So much for the means by which wheels are dispensed with, and the carriage enabled to slide along the line.

The next point is the method of propulsion. Figs. 7 and 8 give an elevation and plan of one of the experimental carriages. Along the under side of each of the carriages a straight turbine, L L, extends the whole length, and water at high pressure impinges on the blades of this turbine from a jet, M, and by this means the carriage is moved along. A parabolic guide, which can be moved in and out of gear by a lever, is placed under the tender, and this on passing strikes the tappet, S, and opens the valve which discharges the water from the jet, M, and this process is repeated every few yards along the whole line. The jets, M, must be placed at such a distance apart that at least one will be able to operate on the shortest train that can be used. In this turbine there are two sets of blades, one above the other, placed with their concave sides in opposite directions, so that one set is used for propelling in one direction and the other in the opposite direction. In Fig. 6 it is seen that the jet, M, for one direction is just high enough to act against the blades, Q, while the other jet is higher, and acts on the blades, P, for propulsion in the opposite direction. The valves, R, which are opened by the tappet, S, are of peculiar construction, and we hope soon to be able to give details of them. Reservoirs (Fig. 6) holding water at high pressure must be placed at intervals, and the pipe, T, carrying high pressure water must run the whole length of the line. Fig. 6 shows a cross section of the rail and carriage, and gives a good idea of the general arrangements. The absence of wheels and of greasing and lubricating arrangements will alone effect a very great saving, as we are informed that on the Lyons Railway, which is 800 kilometers long, the cost of oil and grease exceeds £400,000 per annum. As Sir Edward Watkin recently explained, all the great railway companies have long tried to find a substitute for wheels, and this railway appears to offer a solution of that problem. Mons. Barre thinks that a speed of 200 kilometers (or 120 miles) per hour may be easily and safely attained.

Of course, as there is no heavy locomotive, and as the traction does not depend upon pressure on the rail, the road may be made comparatively light. The force required to move a wagon along the road is very small, Mons. Barre stating, as the result of his experiments, that an effort amounting to less than half a kilogramme is sufficient to move one ton when suspended on a film of water with his improved shoes. It is recommended that the stations be placed at the summit of a double incline, so that on going up one side of the incline the motion of the train may be arrested, and on starting it may be assisted. No brakes are required, as the friction of the shoe against the rail, when the water under pressure is not being forced through, is found to be quite sufficient to bring the train to a standstill in a very short distance. The same water is run into troughs by the side of the line, and can be used over and over again indefinitely, and in the case of long journeys, the water required for the tender could be taken up while the train is running. The principal advantages claimed for the railway are: The absence of vibration and of side rolling motion; the pleasure of traveling is comparable to that of sleighing over a surface of ice, there is no noise, and what is important in town railways, no smoke; no dust is caused by the motion of the train during the journey. It is not easy for the carriages to be thrown from the rails, since any body getting on the rail is easily thrown off by the shoe, and will not be liable to get underneath, as is the case with wheels; the train can be stopped almost instantly, very smoothly, and without shock. Very high speed can be attained; with water at a pressure of 10 kilogrammes, a speed of 140 kilometers per hour can be attained; great facility in climbing up inclines and turning round the curves; as fixed engines are employed to obtain the pressure, there is great economy in the use of coal and construction of boilers, and there is a total absence of the expense of lubrication. It is, however, difficult to see how the railway is to work during a long and severe frost. We hope to give further illustrations at an early date of this remarkable invention.—Industries.

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