The Mechanical Handling and Storing of Material

LOADING COAL INTO SHIPS OTHERWISE THAN BY TIPS 599 is connected by a Details of Fig. 844. Coupling for Ad- justing Shoot of Port Miike Loader. by ropes 28 and drum 29. Spindle 30 carries the drums 29 and 31, and from the latter rope 32 leads over guide 33 to drum 34. • __ . It will thus be seen that all the movements of the rails c, the main portion k of t e shoot, and the sliding block v, are manipulated from the same spindle and move therefore together Minor adjustments can be made in the incline of the lower end of the shoot by the ratchet and tooth rack couplings (Fig. 844), which are inserted between the ropes 11 and 14, manipulating the sliding block v. . After the loader had been at work for several months, an anti-breakage deyæejas added in place of section p; it consists of joint 36 and bend 35, which L universal joint to the upper end of a telescopic shoot. I be utility and the object of this addition are obvious; when the telescopic shoot is not required the extreme ends 38 and 39 may be fastened together by the rings shown, or the whole may be raised round joint 36 by the crane 40. The motive power for these loaders consists of two electiically driven winches of 200 H.P. and 64 H.P. respectively, which are situated in the engine-house seen in Fig. 841. Direct current is used of 500 volts. The speed of the skips is about 3 ft. per second, so that the raising and emptying of the load and the return of the empty skips wilj take one minute, thus the whole cycle of loading operations gives a theoretical capacity of 480 tons per houi for each loader, each charge being 8 tons, but as a few seconds are lost for filling the skips, the actual average capacity is 5,000 tons per day of twelve hours, or say 416 tons per hour. Fig. 845 is interesting, as it gives a view of the two loaders during their erection ; it took forty-seven days to erect the first, and •forty-two days for the second. The principal advantage of this loading system over that of the usual coal tips, in which the railway truck is raised bodily and emptied, is saving of time, as none of the tips accomplish the whole cycle of operations in so short a time. It is true that some tips ha\e a much larger capacity, but the reason for that is, that much laiger loads are handled with each operation, some of the trucks raised and emptied holding up to 50 tons of coal. With the ordinary coal tip so much time is lost in moving the trucks to be emptied on to and off the cradle, whilst in the loading machines at Miike time is saved in this way, because as soon as one skip is filled with the contents of a truck, the skip ascends, and before it is returned empty, the next truck is ready to tip its load into it. In order to construct a loader of a larger capacity it would only be necessary to provide an installation with a larger skip, as the time occupied by the cycle of operations would be practically the same for a larger load. The disadvantage of the loader is, however, one which varies with the quality of the coal, and may be so great as to more than outweigh its advantages by the breakage of the coal. With ordinary tips, some breakage is unavoid- able, and is caused during the tipping of the truck, by the abrasion of the coal, and by the impact between the coal and the lowering shoot; we need not consider the damage caused in the shoot proper, as similar conditions will obtain with both types, provided the shoots are suitable. Now, with the loader under consideration, the breakage should, therefore, be about the same at the dumping point if loads of the same bulk aie handled,