The Mechanical Handling and Storing of Material

534 THE MECHANICAL HANDLING OF MATERIAL strain is put upon the wagon through the two axles, so that there can be no damage to the wagon as would be the case if lifted by the buffers, and the springs and axle-boxes cannot get out of position. The tip consists of the usual platform hinged at one end, and fitted between the rails so as to give a clear way for the wagon to pass over when not in use. This platform is double the length of the wheel base of the trucks ; thus there is a leverage of two to one of the dead weight to be lifted, in favour of the gear. The back axle of the truck is engaged by a cross member of the platform, having two wrought-iron plates fixed on each side, which prevents the axle slipping off as the truck is raised. Plates are also fitted on the fiaming of the cradle under the front axle, so that, if necessary, the whole truck can be lifted off the rails to obtain a sufficient angle for emptying. The winding rope travels across the drum, and thus the angle of the rope to the cradle is never excessive. The simplest form of drive is from a countershaft by open and cross belt. The countershaft is driven by a motor of 10 H.P., the power required to tip a 12-ton wagon. In practice, two truck tippers are often provided as in the illustration, one on either side of the hopper, so that if the end door of the wagon comes in the wrong direction for the one tipper it would be right for the other. A turntable in conjunction with one tippei would obviously answer equally well, though the difference in cost between a well- made turntable and the tipping apparatus would be trifling, whilst the first-named would entail more labour in operation. Tip at the Brentwood Gasworks.—The installation illustrated by Figs. 748 and 749 is at work at the Brentwood Gasworks, and as the coal is taken in there at the rate of only 10 tons, or one truck-load, per hour, the slower working tip answers the purpose quite as well as one fitted with a more powerful pump, and consequently having a quicker action. 1 he hydraulic lifter and pump were built by the Leeds Engineering and Hydraulic Co., Ltd. Ihe pump is a very small one, and is always at work when coal is being.