Submarine Appliances And Their Uses
Deep Sea Diving, &c., &c.

SALVAGE OPERATIONS. It is computed that the value of vessels and cargoes annually lost on the british Coast alone exceeds /g.ooo,ooo sterling. SALVAGE PLANT AND DIVERS. This should in all cases be of the best and most powerful description, fit to cope with vessels of various sizes that may have to be dealt with. We recommend the following as a complete, and perfect salvage plant and personnel : — (1) Skilled and well-tried Divers, preferably ships’ carpenters and boiler- makers—sober and reliable men—with proper equipment of DIVING APPARATUS. Ship’s crew to include MEN CAPABLE OF DEALING WITH HEAVY LIFTS, PURCHASES, etc. (2) PONTOONS.—In some cases considerable BUOYANCY can be gained by attaching PONTOONS (CAMELS') to the sunken vessel, these being" constructed either of iron or steel plates, or of timber. Water-tight barrels, placed in the holds of small wrecks, have also proved of great service. STRONG RUBBER AND CANVAS AlR-BAGS have also been successfully used in the same way, these being placed in the vessel’s hold, or secured to the vessel out- side, and then inflated with air forced down by pumps through a tube attached to the bags, thus displacing the water. (3) At least three 12-in. CENTRIFUGAL PUMPS,* each capable of discharging 150,000 gallons of water per hour ; two loin. Portable Pumps, + each of a capacity of, say, 60,000 gallons an hour ; Boilers ; Flexible India-Rubber Suction Hose, with suitable couplings, Foot Valves and Gratings ; Discharge Pipes, etc. (4) Special Steel Wire Ropes, from 6in. to gin. in circumference, and Chain Cables, for slinging, lifting, and hauling purposes; a stock of screws, 7 feet to 8 feet long by 3 inches in diameter ; Leak Stoppers. (These latter are of simple construction, viz. : —T0 a bar of iron slit through half its length there is jointed in the middle a screwed spindle, half the length of which lies flush in the slit in the bar, the remaining portion forming a handle. If the apparatus is taken in hand with the tip of the thumb on the slit end of the bar. all will be in a straight line, but if the bar is thrust forward through a hole, at the same time re- moving the tip of the thumb, the bar will immediately adjust itself across the hole on the other side, and afford a certain and secure purchase, forming, in fact, the head of a T-headed bolt. A washer-plate to cover the whole of the wound can then be slipped upon the shanked or screwed spindle, and secured to the side of the ship by a tightly screwed-up nut. This washer, or patch plate, can be faced with layers of thick felt, so^ as to embed any jagged edges or irregularities through tile bulging of the wound, and so make a water-tight patch.} Pins Fig. No. 57. Another form of leak-stepper is the “Douglas,” a sort of “umbrella” arrangement, which, being used from inside a ship, is passed through the hole, and then the “um- brella ” is expanded and drawn up tightly against the outside of the skin of the vessel. They arc made for hulls ranging from in. to 6in. thick. * For capacities of various sizes of Centrifugal Pumps, see page 96. t Driven by steam, electric or oil motor. I 28