THE PROBLEMS OF SALVAGING SUNKEN SHIPS.

Star (Christchurch), Issue 18926, 23 November 1929, Page 22 (Supplement)

THE PROBLEMS OF SALVAGING SUNKEN SHIPS.

DAVY JONES’S LOCKER IS RICH IN WRECKS. The recent salvage operations in connection with the P. and O. liner Egypt, sunk off wave-beaten Ushant, attracted world-wide interest. In May, 1920, a French steamer crashed into the vessel, and she sank with a loss of a hundred lives. In her strongroom she carried five tons of gold and 45 tons of silver. For nine years she has lain on the floor of the ocean, some seventy fathoms deep, one of the many wrecks around that rock-bound, storm-beaten coast. The bullion —bars of gold and silver, with 165,000 golden sovereigns, altogether worth more than a million sterling—is encased in the very heart of the ship, beneath the three decks under the saloons. The problems and perils of retrieving the treasure are formidable and manifold, but rich is the reward of success. The attempt last year to recover the jewels in the Belgian steamer Elizabethville, sunk by a German submarine off Belle lie in 1917, was followed with intense interest. The Elizabethville, a 12,000-ton vessel, carried 13,000 carats of diamonds and quantities of other precious stones,- valued at £1,250,000. It was found that the steamer struck a rock in sinking and broke her back in two places, lying in three portions at a depth of 230 ft, the steeply tilted deck and the strong currents making the work of the divers particularly dangerous. Great was the disappointment when, after much trouble in reaching the mailroom by the use of dynamite charges and the removal of huge masses of metal, prolonged search failed to locate the jewels. The Steamer Lusitania. Operations in connection with the Lusitania will be undertaken ‘later on, and they are sure to excite the greatest public interest owiftg to the poignant memory of her dastardly sinking. Many of the ships sunk by enemy submarines lie close in shore, for the Germans hoped, after conquering the Allies, to reap a rich harvest by salvage. The Laurentic, for example, was deliberately sunk in a chosen position off the Irish coast, and a strict submarine watch instituted to prevent the bullion being raised. Before the end of the war, however, almost the whole of the five millions sterling had been recovered by daring and skilful British divers. Once, when a German submarine interrupted the work, the salvage ship “ran for it” and the diver was dragged through the ocean in full kit for seven miles. The story of salvage, says Mr An thony Clyne, fs a record of the acu men of scientific investigators, the ingenuity of inventors, the consummate technical skill of practical experts, and above all the courage, resource and pertinacity of divers—spiced with sensa tional but true tales of adventures en countered in raising treasure or documents, or a 24,000-ton battleship, or, most moving of all, yet breathing men imprisoned in a sunken submarine. Risks Taken by Divers. There was that enthralling tale of treasure raised in Chinese seas, then a race to an island to get water for the exhausted diver, and finally the ap proaching sails of pirate junks seen just in time. Or that of diving to recover secret orders from' a sunken German submarine, and finding them in a stiffened hand protruding from the conning tower. As the submarine plunged to her doom the cover had slammed against the arm of the commander ridding himself of his papers. Or of sharks. “If a shark persists in disturbing you at your work,” says a diver, “ you signal up for a knife, hold out your hand as bait, like a bone to a dog, and stab the brute as he turns. As for the octopus, you squirt air at him.” Presumably, but for one’s helmet, one would just make faces at him. It is difficult to conceive' the conditions in which the diver works. Even at the comparatively small depth of fifty fathoms, the water is so dense that it takes a concentrated effort to lift a hand. Diving suits are construct ed of cast steel cylinders with jointed iron legs, desighed to withstand immense pressure. When air cannot be supplied by pipi line, owing to the danger of the pipe being twisted or severed, the suit contains compressed air bottles.Constant communication with the ship is maintained by telephone and cable. The apparatus weighs over 8001 b but in the water the effective weight is 401 b. The diver is brought to the surface slowly, stopping every so many feet to perform physical exercise designed to prevent the formation of bubbles of nitrogen in the blood. Each kind and size of vessel, each situatiqn, and set of conditions, presents its peculiar case during the war, monitors dug trenches 12ft long under a vessel in order that thirty-two wire ropes could be placed in position and the ship, weighing 5200 tons, lifted by the barges. The salvaging of a battleship is a totally different proposition from that of a merchant vessel. Enormous masses of metal, sometimes over 200 tons in weight, have to be dealt with The German ships in Scapa Flow stand in awkward positions. The Hindenburg upright, the Derfflinger went dowi her side, the Seidlitz bottom up, while .-.(»me of the cruisers have bows poking t traight up. The salvaging of these battleships is a task of years. A noteworthy feat was the raising of the Vindictive, so heroically sunk to block the harbour of Ostend in May, 1918. Just as she had been brought to the surface and put in a condition to be brought home as a relic of an immortal exploit, bad weather came up, and during a gale, her back was broken. All the bulkheads of the Vindictive had been shattered and the bottom nearly blown to pieces by the charges used in sinking her. The removal of concrete and mud proved a protracted and arduous undertaking. In the end the structure had to be tied together with very heavy girders, and after it had been raised, the historic vessel was presented to the King of the Belgians Salvage ships are equipped with a great variety of engineering appliances and carry an abundance of dynamite charges of carefully graduated sizes. There are huge cranes and derricks capable of hoisting up to fifty tons Everything that is employed in the sea has to be of special material or pattern to resist the action of water. Ihe modern diver uses pneumatic tools, worked by compressed air. Men expert in all branches of engineering are carried, and special tools have often to be made on board. Sometimes pontoons and hollow iron tanks are used, of various shapes and sizes to fit tightly around a wreclf. These are fastened in position, and when the water is pumped out, exert an enormous lifting power. The salvage ship herself, with immense strength of hull, and with powerful engines for towing, when manoeuvred to take ad vantage of the rising tide, is like a huge tool, exerting tremendous leverage.