The Mechanical Handling and Storing of Material

THE COALING OF RAILWAY ENGINES 619 of about 1 ton per minute. To avoid jamming the buckets in the pit by an accumulation of coal, and so preventing the motor from starting, an automatic switch has been devised, which by the action of raising a slide and admitting coal into the pit, starts the motor before the slide is sufficiently raised to admit coal in any quantity, a water spray to lay the dust being simultaneously turned on. The coal is delivered close to the top of the tender, gear being provided to lift the shoot clear of the chimney and cab of the engine.1 American Practice.—Extensive coaling installations have there been erected for locomotives.2 They are much larger than similar installations in Europe, as in America they have been able to centralise and make more economical arrangements, and also the country being new, the value of the land occupied by these installations is considerably less than in European countries, where the already existing arrangements often only admit of a limited space for the installation of such plant. Finally, the exceptionally high wages in the United States are a special incentive to mechanical equipments, for which reason comparatively few small in- stallations are to be found. The most universally adopted method of coaling railway engines consists of timber ramps constructed of trestle-work, up which the coal wagons are hauled by a loco- motive ; here the coal trucks, which are hopper-bottomed, are dumped into pockets, the outlets of which are sufficiently high above the ground for the coal to be shot direct by means of a shoot into the tenders. Such installations are extra- Fig. 873. Cross Section through American Gravity Coalin: Installation. (The dimensions are in metres.) vagant for space, which would probably not be available in England except in one or two places; but the fact that the land has in many cases been given free of cost in America makes the study of space economy less important. It is obvious that the greater the incline of these ramps the shorter will be their length. The most usual incline is one of 6 per cent, or 1 in 16-7, at which incline one locomotive can haul three 50-ton wagons. If the local conditions do not permit of the necessary space for such a ramp, and a steeper incline becomes necessary, the wagons are hauled up by a rope, which service is occasionally performed by locomotive. The inclines are then up to 20 per cent, and even more. I he high level rails at the top of these ramps have frequently a slight downward gradient in the opposite direction, so that a wagon cannot accidentally run down. A further pre- caution against accidents is the use of safety switches. Fig. 873 shows a cross section through the highest portion of one of these devices, from which it will be seen that 1 From The Engineer, 23rd May 1902. 2 “Lokomotivstationen nordamerikanischer Eisenbahnan,” by Dr Blum and E. Giese, Zweitschrift des Vereines deutscher Ingenieure, 8th Feb. 1908.