The Mechanical Handling and Storing of Material

STORING OF COAL AND OTHER MINERALS 661 is loaded into cars by the crane and carried to the boilers. 40-lb. rails are embedded in the bottom of the pit, 18 in. pitch, with | in. of the head standing above the surface to prevent the bucket from striking the concrete. The pit is filled with water up to the ground level, and covers 13,000 tons of coal. The water is pumped into the pit by a 4-in. centrifugal pump, taking the water from the pump-house supply well, and it enters the pit at the ground level. Through the centre of the pit and beneath the trestle there is a trough 12 ft. wide and .1 ft. deep, which serves, as a drainage. It is fitted with a drain pipe which carries the water to either of two man- holes, one at each end of the pit. The outlet openings are protected by gratings to prevent any coal from entering the drain pipe. The pit was designed by Thos. A. Wynne, Vice-President of the Company, and was built under his supervision. The locomotive crane and bucket were furnished by the Brown Hoisting Machinery Co., of Cleveland, Ohio. Mechanically Equipped Salt Store.—An interesting store mechanically equipped for storing and withdrawing salt or any similar material in bulk is shown in Fig. 934. The principal mechanical agent in this case is a mono-rail, the skips or buckets of which Fig. 934-. Mechanically Equipped Salt Store. (The dimensions are in millimetres.) are used either to bring salt in or to take it out. The length of the store is 42 m., or 138 ft., and it holds 5,000 tons of salt. It is attached to a mill in which the salt is ground and the mono-rail telphers bring it on two lines b and c for warehousing, whilst line h is used for withdrawing the salt to the railway siding. When loading from lines b and c the self-tipping skips discharge automatically as shown. For withdrawing from line Ji the skips are filled from a loader e which is kept full by the portable device i and an electrically driven hoist skip. The device i consists of a scraper conveyor which travels the whole length of the store and takes the salt from the heap to the hoisting skip. The conveyor can work at any angle either as shown or it can dip down into the hopper bottom of the store and fetch the salt from there. The capacity of the mechanical installation is 60 tons per hour, two skips being used, and the driving power consumed is only 3 H.P. The plant was built by Messrs Luther, of Brunswick. The Storing of Coal in Silos.—The most economical method of storing coal or minerals is in elevated silos or bins. This system has been adopted for many years as far as grain and seeds are concerned, but it is only of comparatively recent years that it has been adopted for the storing of coal and minerals, more particularly on the Continent and in America.