The Mechanical Handling and Storing of Material

UNLOADING VESSELS BY BARGE OR SHIP ELEVATORS 463 as Indian wheats, some oil seeds, nuts, flour, coffee, peas, lentils, salt, moist sugar, cement, etc. Hitherto such goods have been unloaded by intermittent appliances such as cranes, mono-rail telphers, or other elevated devices manipulated by chains or cables, which have the decided disadvantage of having to waste time waiting for the return of the empty receptacle for the next load; this is unavoidable with all intermittent methods of handling. The first installation to solve the problem of unloading such goods in a continuous operation, similar to the handling of bulk goods, was erected on a quay on the Danube at Vienna in 1910-11 by Amme, Giesecke & Konegen, of Brunswick, Germany. Sacks have been conveyed for years by band conveyors on the level or on slight inclines, so that this part of the • present installation presents no novelty; what had Fig. 642. Elevator at Avonmouth Docks when at Work. hitherto been unknown was the use of an elevator in combination with such band conveyors. The elevator consists essentially of the usual upper and lower terminals with two chains, which are transversely connected at intervals by cross bearers upon which the sacks stand. The elevator is slightly inclined, and the space between the chains is fitted with a wooden back against which the sacks lean and slide during their ascent. Figs. 643 and 644 show the general arrangement of the unloader, whilst Fig. 645 shows the relative position of the unloader to the warehouse. It will be seen from these illustrations that the banks of the Danube are of a gentle incline, and although there is no tide the water level varies considerably at different seasons of the year. I he sloping banks make it imperative that at high water the barges to be unloaded shall come nearer to the warehouse. It is thus necessary to have the jib which receives the sacks from the