The Mechanical Handling and Storing of Material

678 THE MECHANICAL HANDLING OF MATERIAL by 172 ft., within which are contained 250 hexagonal bins of brickwork, each measuring 12 ft. across the angles by 80 ft. in depth, besides a large number of half bins next to the main walls, which are used exclusively for delivering into sacks. I he total capacity of the bins is 80,000 tons. On three sides there are lean-to sheds, in which the processes of weighing, sacking, and delivering are carried on. Ihe walls of the bins are 14 in. thick up to a height of 27 ft., and 9 in. for the remaining 63 ft. (see Fig. 958). The top of each bin is provided with a fireproof cover, through which there are manholes with raised lips for the passage of the grain. These raised lips are intended to prevent water from penetrating into the interior of the bins. Elevators.—The grain is lifted from barges by four elevators on the dock side, and is conveyed to the granary on the bands running Figs. 961 and 962. Plan and Section of Sub- way under Quay and Roadway showing Band Conveyor connecting the Branch Dock with the Alexandra Grain Ware- house. in subways which pass under the quay and Regent Road. At No. 1 Alexandra Branch Dock there are two outside elevators (Figs. 959 and 960), each having a nominal lifting capa- city of 75 tons per hour. The grain is elevated from the hold of the barges by these elevators, lifted 43 ft., and delivered into receiving hopper a, from which it is again lifted 32 ft. by a second elevator inside the tower. It is then received into a second hopper b, thence it flows by gravity to a weighing hopper c underneath, which weighs 2 tons at a time, and delivers into a distribut- ing hopper d beneath. This hopper holds enough grain to maintain a continuous feed for the band conveyors, and is at the same time of sufficient capacity to receive the intermittent deliveries fiom the weighing hopper c. Mechanical shovels or scrapers are employed in the hold for trimming the grain to the elevators, and are operated by ropes wound on a friction winch in the tower, which has an alternate reversing motion. The ropes are guided into the hold by snatch-blocks, so as to move the scrapers alternately in a fore and aft direction. When it is desired to deliver the grain to the dock-side sheds instead of into the bins, it is discharged either through spouts from the top of the inside elevator, or from the distributing hopper beneath the weighing machine. Portable bands supported on trestles are used for removing grain from this point to the floors of the sheds. At No. 2 Alexandra Branch Dock there are two similar towers with elevators and other appliances as above described, each elevator having 100 tons’ nominal lifting capacity per hour, but being capable of discharging and weighing at the rate of 145 tons per hour. Band Conveyors.—The grain is carried from No. 1 Branch Dock elevators on two