The Mechanical Handling and Storing of Material

CHAPTER XXXIII FLOATING LOADING DEVICES, INCLUDING SELF-EMPTYING BARGES ? With the advent of larger vessels the difficulty of loading bunker coal has increased. The larger the ship the more difficult it is to bunker from the quay wall, and for years past the tips for loading have been made portable within narrow limits to accommodate themselves to some extent to the position of the ship, but even with this improvement the adaptability of a floating loading device can never even be approached for portability by a device on shore. On the other hand it can hardly be expected that such floating loading devices can compete as regards capacity with the enormous quantities of cargo coal which may be poured into a vessel by the tips on the quay wall. For bunkering, however, and as an auxiliary to the tip from the waterside, the floating loader is invaluable. These latter are of two types : (A) Those self-contained and carrying the coal to be transferred, generally known as self-unloading or self-trimming barges; and (B) those which Fig. 655. Paul’s Self-Trimming Barge. carry no cargo of coal, but transfer by mechanical means the contents of a lighter or barge into another vessel. Self-trimming barges are used for the purpose of transferring their contents, which may be grain, coal, etc., to other vessels, or to the receiving elevators or conveyors of granaries and coal stores. A.—SELF-EMPTYING OR SELF-TRIMMING BARGES Paul’s Self-Trimming- Barge.1—One of the oldest self-trimmers, which is, however, not entirely automatic, is the design of the French engineer, M. J. Paul, and will, it is claimed, successfully handle grain, coal, sand, etc. Fig. 655 shows such a barge, which has a double bottom forming a hollow space bb on either side of the channel a, in which a travelling trough conveyor is fitted in such a way that its delivery end over the bow is movable like a derrick. Section AC of the conveyor can, therefore, be raised or lowered to suit the requirements of the delivery. The angle must not, however, exceed 45°. When not at work the movable part can be housed as shown in dotted lines. The contents of the barge are fed to the conveyor through the 1 This barge has been minutely described by Professor Buhle. 476