The Mechanical Handling and Storing of Material

THE WAREHOUSING OF GRAIN 671 The principal operations to be effected by the aid of machinery were as follows :— Discharging grain in bulk from vessels or small craft directly on to the quay ; discharging ordinary merchandise direct on to the quay, or carrying it to any floor of the warehouse, and loading outward-bound vessels; lifting and lowering sacks, bags, and other merchandise on lifts and hoists to or from any floor; elevating, screening, weighing, and distributing grain, and conveying it to or from all parts of the warehouses to any other part and back again as required for conditioning damp or heated grain. The best means of effecting these operations were the subject of much consideration and of many and costly experiments, particular attention being paid to the question of the kind of power to be used, and the most convenient, economical, and practical method of applying and distributing the power. Ultimately it was decided that a hydraulic system of power distribution best met the requirements of the case, electric driving not having been thought of at that time. As the result of experiments, band conveyors were adopted for transporting grain horizontally from one part of the warehouse to another. The maximum quantity of grain conveyed Fig. 944. Grain Receiving and Distributing at the Liverpool Dock Granaries. by an 18-in. band is at the rate of about 70 tons per hour, and it was ascertained that the power required to drive the band when fully loaded and delivering at that speed was infinitely smaller than with a worm. In order to save labour in spreading the grain over the floors of the warehouses, and also to condition it by ventilation, a revolving fan with a scattering action was tried with success as shown at N in tig. 943. This fan is placed 9 ft. 6 in. above the ground, and at its usual speed of 250 revs, per minute deposits the grain over an area of 45 ft. in diameter. Five hydraulic cranes for discharging vessels are fixed in towers specially constructed in the warehouses, one of which is shown at o in Fig. 943. These cranes are arranged for raising grain in skips containing 21 cwt. of bulk, at a maximum rate of 50 tons per hour. The hopper p (Fig. 944) into which the grain is dropped from the skip holds about 8 tons of grain, and from this hopper the grain is diverted into two streams, and allowed to flow through spouts fitted with regulators on to two. 18-in. inclined bands Q. The construction of the elevators (Fig. 943) for raising the grain from the bottom to the top of the warehouses is shown to a larger scale in Fig. 945. The wrought-iron skip