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

Deep Where there is no rise and fall of tide, and where pumping machinery could not be Salvage. successfully used, the plan is to sling the wreck by means of wire hawsers led up to two hulks moored over the sunken vessel, and which generally have water pumped into them in order to sink them as far as possible consistent with safety. In some cases pontoons are then attached to the sides of the sunken vessel (these pontoons are sunk by letting water into them, which is expelled by means of a powerful air pump when they are placed in posi- tion by the Divers). When all is secure the hulks are pumped out and the water expelled from the pontoons simultaneously. By this means a good strain is secured, and the wreck is lifted off the bottom, and can then be towed into shallower water. Instead of hulks, on several occasions large pontoons alone have been successfully used in the raising of sunken vessels. These pontoons are constructed of timber or of steel plates, and are divided into compart- ments, which can be filled with water to sink them as far as possible with safety, or pumped out, as desired, the lifting being done pretty much in the same manner as in the case of the hulks described above. Passing In cases where it is found expedient to take wire ropes right round the hulls of smaller wire ropes vessels, the readiest method of passing them under the keel is to use a hose-pipe, one end of vessels. which is connected to a pump, the other end being directed under the keel to force a channel through the sand, etc. With a good pressure this device will be found more expeditious than the old system of pricking a way under the keel and passing a small pilot chain through to make way for the larger lifting hawser. The following are a few examples of successful ship-raising operations carried out with the aid of Centrifugal Pumping Engines and Divers :— H.M.S. H.M. S. Sultan, sunk between Malta and Gozo, and raised by Messrs. Baghino Brothers, Sultan. Genoa. In this case it was found necessary to blow away projections of rock by means of small charges of dynamite, which had to be carefully used in order to avoid further damaging the vessel. All holes and apertures were then stopped up by means of timber, bricks and a special cement {Medina), which has the properties of setting quickly and adhering to iron ; the suction pipes from the Salvage Pumps were then introduced into the wreck by the clivers, and Pumping commenced. H.M.S. t H.M.S. Howe, 10,300 tons, 11,500 h.p., length 325ft., breadth 68ft., depth 26ft., four Howe. 57-ton guns, stranded on Pereiro Reef, entrance to Ferrol, Spain, 2nd November, 1892. The Howe listed over to starboard 20 degrees, and at high water her fore-deck was entirely covered. Projections of the rock on which she stranded penetrated right through her double bottom, and had to be carefully blasted away by small charges of dynamite. A large shield was constructed and fixed over the damaged parts by Divers, and the vessel was then pumped out. Before she could be floated, however, it was found necessary to blast away the rocks (about 400 cubic feet) all round her, which was done by means of charges of dynamite, a rock drill, driven by compressed air, being used for boring the holes for the charges. 1 he Howe was floated by the Neptune Salvage Company, of Stockholm, who, without doubt, possess the most powerful and complete salvage plant in the world. The operations were carried out under the superintendence of Capt. Edlind. This Company, since its formation, has under- taken over 1,500 different salvage operations, representing a value, in its damaged condition, of over £6,000,000 sterling. (See photo, page 131.) s.s S.s. Utopia, sunk off Gibraltar in about 50ft. of water, had a coffer-dam attached to Utopia. jier gUnwajes by Divers, and was then pumped out and floated. S.S. Argus, sunk at Birkenhead, had a wooden coffer-dam built on to her deck, and "Argus.” the holes in her side, caused by the collision, were patched up by Divers. Salvage pumps were then used to pump out the water in the vessel’s hold, and she was ultimately floated and towed into a safe place. The salvors of this vessel and of the S.S. Utopia were the East Coast Salvage Company, of Leith (Mr. T. N. Armit, Superintendent). Somewhat similar methods were employed in the case of the S.S. Kottingham, also raised by Mr. Armit (see page 139). 13°