The Mechanical Handling and Storing of Material

466 THE MECHANICAL HANDLING OF MATERIAL with its motor from a hook on the crane, is exceedingly flexible, so that almost all points of the ship’s hold can be reached, which reduces trimming to a minimum. The capacity of this device is 40 tons per hour. The housing of the device is fairly simple. By means of the hand wheel and chain a and b, the worm is raised sufficiently to disengage from a portable weighing house, when an auxiliary electric winch on the crane shortens the rope <r, so that the telescopic worm closes up till it is home in position d, where it is held closed by an automatic catch. If rope c is now slackened the worm drops close to the side of the elevator and the whole apparatus can be swung out oft'he way and housed till required for future use. The Mitchell Cantilever Grain-Discharging Elevators at Dunston on- Tyne.—The Co-operative Wholesale Society, Ltd., have installed, in connection with their flour mill at Dunston, two large ship-discharging elevators of an unusual design (see Fig. 649). These elevators are the last link in a chain of improvements and develop- Figs. 646 and 647. Jib with Band Conveyor for Handling Sacks. (The d’aiensions are in millimetres.) merits which have been carried out in connection with this establishment. Joimeily the whole of the foreign grain required for their mills had to be discharged at the docks lower down the river and from thence brought by steam barges to the mill at Dunston. In order to save 'all the expenses of storing and handling large quantities of grain several times, the Directors decided to put up a most complete plant for discharging and storing large cargoes of wheat. At the jetty on the eastern side of the mill steamers up to 7,500 tons can Jie alongside at any state of the tide and by means of the two elevators a very quick delivery can be effected. 1 he elevators were designed on the principle of Mr A. H. Mitchell, the bulk grain engineer of the Port of London Authority. I hey are the first of the kind which have been erected as travelling elevators on shore, the Mitchell Patent having been more especially used in connection with floating elevatois. One of the chief points to be borne in mind in designing the installation was the rise and fall of the tide (20 ft.). The essential feature of these unloaders is that the jib, which supports the elevator, is not in a fixed position, and owing to an ingenious arrange- ment of balance weights the jibs can be moved backward or forward, the effect being