The Mechanical Handling and Storing of Material

482 THE MECHANICAL HANDLING OE MATERIAL contents; or two such barges would have to be at work, one discharging whilst the other replenished; or, thirdly, the bunkering could be done partly by a stationary tip at the dock side, and partly by one of these loaders from the water side. This shows that the systems hitherto described are hardly adequate for bunkering large liners in a minimum of time, but we shall see later that the floating loading devices that carry no cargo coal, but simply transfer the contents of coal barges to ships’ bunkers, have adequate capacity for coaling the largest liners. Before describing these, however, we must mention two more self-trimming barges, one of which is specially built to work in conjunction with floating coal loaders, and the other for handling grain. The Doxford Self-Trimming- Barge.—These barges are built by William Doxford & Sons, of Sunderland, to serve the loaders. Fig. 672 shows one of these barges : Figs. 669 to 671. Coal Loader at the Doxford Wharf, Sunderland. (The dimensions are in millimetres.) a is the coal receptacle, B the conveyor, and c and d the final delivery. The general arrangement is not unlike that shown in Figs. 666 and 667, but the delivery shoot is only just high enough to deliver into the elevator of the loader. The capacity of each barge is 650 tons of coal, which is paid out into the loader at the rate of 250 tons per hour. A barge of this kind feeding its loader is shown in section in Fig. 676. Philip’s Self Trimming Lighter.—This is illustrated in Fig. 673, which gives a longitudinal section of the same, whilst a cross section is shown in Fig. 674. Fig. 675 gives the two ends of the lighter on a larger scale. These boats were designed and equipped by Messrs Spencer & Co., Ltd., of Melksham, for the London Grain Elevator Co. There is a fleet of twenty-six of these lighters, each of which carries a" load of 200 tons of grain from Tilbury to the Port of London, some of the large grain steamers not usually coming up higher than Tilbury. The lighters discharge grain at the rate of