The Mechanical Handling and Storing of Material

FLOATING LOADING DEVICES 477 openings p, which are adjustable by means of slides, hand wheels, and screws. In order to enhance the carrying capacity of this barge, the sloping bottom has been made rather flat so that some hand-trimming is necessary, d represents the engine and boiler. Clarke’s Self-Trimming Barge.—One of these barges has been in use at Liverpool for upwards of twenty years by the Liverpool Barge and Coaling Co. Fig. 656 shows an elevation in diagrammatical outline, whilst Figs. 657 to 660 show four cross sections giving the different stages of discharge, and they show also how coal of different kinds may be mixed on delivery. In the space between the double keelsons of the barge a gravity bucket conveyor a is provided, which takes the coal to the upper structure and delivers, after passing two automatic weighing machines, to the delivery shoots b, c, d, and e. I here are two such barges used at Liverpool, with a capacity of 1,300 tons each, which can be transferred at the rate of 230 to 250 tons per hour; they require six men each to handle them. In addition to the barges on the Clarke principle, just described, the Hamburg- American Line has a similar installation on order for the Hamburg harbour, which shows that although this system is more than twenty years old, it is still considered up to date. Fig. 657. Fig. 658. Fig. 659. Fig. 660. The barge is to be fitted with a crane and grab, so that it can be replenished all the time without having to come alongside for recharging, as there are no suitable tips available at Hamburg for this purpose. The capacity per hour is 250 tons for the gravity bucket conveyor, and for the crane and grab, for replenishing, 150 tons. The height of lift is 48 ft., which is lower than that at Liverpool. It might be mentioned that it is inadvisable to make such floating loaders too high and top-heavy, and to afford much resistance to the wind in the superimposed structure, as a high wind and an empty barge might prove disastrous; this was probably considered when ordering the self-unloading barge for Hamburg, as somewhere about Christmas 1912 two loaders capsized there. Self-Trimming Barge in New York Harbour.1—This is on the same principle 1 This barge was fully described in the Journal of the American Society of Naval Engineers, February 1901.