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

(5) Batteries (preferably of the “Twist” type, which are capable of firing either high or low tension detonators) and INSULATED WIRES with DETONATORS for firing charges of dynamite, or other suitable explosives under water. (6) Submarine Electric Lamps, for under-water use, and Powerful Arc Lamps FOR SURFACE OPERATIONS AT NIGHT. (7) Steam Winches for working heavy loads cargo; Slings; Purchases, etc., for heaving off ships. (8) A stock of QUICK-SETTING CEMENT (“Medina”) and BRICKS should be kept on board the salvage vessel ; in certain cases few better plans can be adopted for stopping up boles. This method was employed when raising H.M.S. Sultan. (9) A supply of Dynamite, or “Tonite” or other explosive, suitable for sub- marine work, with waterproof bags or tin canisters for holding the charges (or “Tonite” can be had made up in water-tight cartridges ready for use).* (10) Pneumatic Rock Drills, Drills for drilling iron or steel. Augers for boring timber, with AIR COMPRESSORS for working same, and also for forcing water out of pon- toons, etc. (11) HULKS, each having a d.w. capacity of 500 or 600 tons, and fitted with steam winches or cranes, arc also of great service, particularly in the case of deep-water wrecks. (12) A good supply of TIMBER and WROUGHT-IRON, for making special bolts, etc. METHODS EMPLOYED. It is not possible to lay down any hard and fast rule for the carrying out of salvage operations, the modus operandi depending so much upon the depth of water and position in which the wrecked vessel is lying, her tonnage, and the nature and extent of the damage. In- variably, however, the first step to take is to send down Divers to survey the vessel and make a thorough examination with a view to ascertaining the extent of the damage. The Divers having given an accurate report, the next thing to be done is to map out a plan of opera- tions, taking into consideration the nature of appliances at hand, tides, weather, etc. CENTRIFUGAL PUMPING MACHINERY FOR SHALLOW WATER SALVAGE. Where the depth of water to be dealt with does not exceed 30ft., Centrifugal Pumps are the most effectual appliances to use. Divers should be sent down to clear away any obstacles that might impede the operations, to remove the cargo if necessary, to stop up holes and repair the damage to the vessel’s hull, and to batten down openings and strengthen the decks preparatory to fixing the suction pipes from the Salvage Pumps. LIFTING CRAFT, PONTOONS, WIRE ROPES, ETC., FOR DEEP WATER SALVAGE. In cases where the vessel is sunk so deep as to make the use of pumping machinery ineffectual, the salvors will have to resort to lifting vessels, or large pontoons, moored over the wreck. A method often employed where there is a rise and fall of tide is to have two or more hulks braced together by baulks of timber, and having sufficient combined buoyancy to allow a good margin over and above the dead weight to be lifted, moored over the wreck ; wire lopes are then attached to, or placed under, the vessel by the Divers, and carried up over sheaves on the lifting hulks. At the rise of tide the wreck is lifted off the bottom, and the hulks are then towed into shallower water, the slack of the ropes being taken up, and the operation repeated until the vessel is left high and dry. * See notes on Explosives, page 99. I 20