The Mechanical Handling and Storing of Material

ENDLESS ROPE AND CHAIN HAULAGE 249 length of rail or pipe is bent into the form of an inclined plane, and set alongside the track, so that the lower end of the incline will just catch under the down-turned lip of the truck body, and as the truck is drawn along the incline, the body is raised until it regains its upright position (see Fig. 352). At the Premier Diamond Mines endless rope haulages are used throughout the workings. The main haulage of one installation has three changes of grade, the steepest being 1 in 8, or 12j per cent.; the tracks are laid with 40-lb. rails set on wooden sleepers, width between up and down tracks 6 ft. The rope is of plough steel, 1| in. diameter, travelling about 4| miles per hour. The rate of hooking on this haulage is from 1,000 to 1,200 truck loads per hour, although over 26,000 loads have been hauled in a working Figs. 350 and 351. Automatic Truck Tippers. day of twenty-one hours, and over 140,000 loads in the week. The length of incline from onset to apex is 3,123 ft., and the vertical lift 239 ft. Another haulage plant at the same mine has two changes of grade, 1 in 8’9 (1-1'2 per cent.) and 1 in 8 (12J per cent.), respectively. The tracks are also laid with 40-lb. rails, 8 ft. centres between tracks; the rope is the same and travels at about the same rate, and has the same capacity as the previous haulage referred to. 'The length of incline is 2,425 ft., and the vertical lift 270 ft. Fig. 353 represents an appliance for the same purpose as Fig. 346, in which the tubs are conveyed uphill by ropes, which engage with the “ jockey ” at the top of the tub instead of with the axle as in the preceding drawing. It also shows the two terminals with the driving gear, and the tightening arrangement by means of a weight at the lower terminus. Other Examples of Rope Haulage, where, however, the rope engages with the lower part of the trucks, are represented in Figs. 354 and 355, which show the method employed by Bullivant & Co. for detaching a truck from the hauling rope. The detacher, which is fixed upon the sleepers, automatically uncouples a clip on the rope, when the lever of the clip strikes against the detacher. Figs. 356 and 357 show the same clip as fitted with a connecting rod and draw-bar with springs, which reduce the shock which may take place in attaching the clip to the rope. The head of the clip is fitted with two springs which connect to a bracket attached to the truck as shown. When the clip is released by the automatic detacher (see Figs. 354 and 355), or by hand, the springs lift the clip clear of the rails, as shown in Figs. 356 and 357,