The Mechanical Handling and Storing of Material

356 THE MECHANICAL HANDLING OF MATERIAL Street car electro-motors, with brakes and controllers, are used throughout the installations, two 125 H.P. Westinghouse railway motors accomplishing the digging and hoisting, whilst two of 35 H.P. give the transverse motion to each trolley. The current is transmitted to the trolley by conductor rails, one being placed on each side of the bridge, about 23 ft. apart. Two cast-iron shoe collectors are provided to each rail, in order to prevent sparking under maximum demands of 900 amperes. At each end of the bridge provision is made against a runaway, in the shape of Fig. 496. Part Section through Vessel. A. Scraper. B. Pull-back Tackle. C. Bulkhead. D. Middle Bulkhead Hooks. E. Stanchion Bulkhead Bracket. F. Stanchion Block. G. Sleeve Nut. H. Stanchion. J. Bulkhead Pennant. K. Double Eyebolt for Bulkhead. L. Side Pennant, f-in. Rope. M. Hold-back Hooks. twelve Westinghouse friction drawheads which act as buffers. These have been found very efficient in checking heavy trolleys. The bridges rest upon standard gauge tracks, placed upon concrete walls 33 ft. high. The transporter itself has a novel function in respect to its movement, having the capacity to assume positions not necessarily at right angles to the axis of the supporting tracks. One end of the bridge may thus be kept stationary while the other end is moved a distance of 300 ft., thereby giving an elasticity to the work which is highly desirable. In this way all the operations at the furnace side of the ore yard may be effected