OCEAN 'DROMES

Evening Post, Volume CXL, Issue 149, 21 December 1945, Page 4

OCEAN 'DROMES

FUTURE POSSIBILITY

ENGINEERING ON WATER

British scientists have found a way of increasing the natural surface tension of water, making it technically possible to build a mid-Atlantic seadrome or a floating cross-Channel bridge., This has been disclosed by the Admiralty, says the "Daily Telegraph." j??his latest discovery in engineering on water has been sponsored and developed by the Royal Navy. It began when an inventor's brain-wave sent him motor-cycling at 50 m.p.h. along a tarpaulin stretched over a river ford. Ordinary tension will support a needle on the water's surface. By putting a flexible synthetic surface on the sea, and by increasing the tension about 400,000 times, it has been found possible to support heavy lorries and aircraft in mid ocean. One practical result is the production of man-made "islands." composed of hundreds of hexagonal buoyancy cans. These "islands" can be built to any shape or length required and can be easily dismantled, transported and reassembled. A FLOATING PIER. Another development, which has already stood up to the severe practical tests of war, is the "Swiss roll." This is a floating pier that can be rolled up, carried on board ship and rolled out again from ship to shore. The "inventor of these devices is Mr. R. M. Hamilton, of Victoria Street, London, who served at the beginning, of the war as a petty officer in the Royal Naval Patrol Service. He is an inventor by profession, and began to consider the possibilities of floating airports in 1941. Co-operating on the involved mathematical calculations required was Mr. J. S. Herbert, housemaster at Eton College. " "Further developments from the original discovery are being made," Mr. Hamilton said, "but for the time being their nature must remain secret." Mr. Hamilton borrowed a length of farm paling and some tarpaulin from a local farmer at Farnham, Surrey, where he was staying. He bridged a local ford with them and crossed on his motor-cycle. He found, as he had expected, that he was being supported on the surface of the water. He also noticed that as he went at speed he was, so to speak, making a harder surface. It was not until' 1944 that the first practical result was employed—the "Swiss Roll" pier, used in the Normandy invasion. In this flexible canvas-and-wood jetty a tension of 18 to 30 tons is applied to any length stretching from ship to beach. The result is that a laden lorry can be driven ashore in safety over the sea.

USED IN INVASION. Some 2700 feet of "Swiss Roll" were in continual use at the invasion harjbour at Avranches in spite of the appalling weather. The Navy's latest experiments, only recently concluded, have been with a further development of the same fundamental principle, th"c "Lily floating airstrip. * Given its name because of its resemblance to a carpet of lily leaves on a pond, "Lily" is a very different proposition to "Swiss Roll.' It consists of numbers of buoyancy cans.with hexagonal surfaces, so linked together that they "give" in a controlled manner to the motion of the sea from any direction, yet remain sufficiently rigid to take the weight of a heavy;aircraft. The Navy's experimental airstrip is the smallest on which practical tests could be undertaken, 520 feet long and 60 feet across. On this an aircraft, laden to 9000 pounds, has been landed and has taken off again. A strip of this size can be assembled by 40 men in one hour. At present the cans are only six feet across and 30 inches deep, but their size could be scaled up to take greatly increased WThe whole surface of "Lily" is flexible so that it will not break up, but this flexibility is controlled by. the use of -under-water dampers. The inventor claims that with the latest-type damipers "Lily" will remain flat m waves up to 36 feet from crest to crest. The dream of Atlantic seadromes has hitherto been unattainable because it has not been possible to. build large enough storm-proof flat-surface structures, 22-MILE BRIDGE POSSIBLE. "Lily's" possibilities for bridgebuilding are "emphasised by those responsible for its development. • "To mention a cross-Channel bridge immediately places you with straws in your hair," said Mr. Herbert, the mathematician. "But we can say that it would be possible to build a floating bridge 22 miles long that would not 'The principles of "Lily" are so new that it cannot be described in usual terms. In fact, when patents were taken out the Patent Office did not know in which category to place the invention. Mr. Herbert likes to refer to it as "rolling dynamic buoyancy, or as "a controllable flexible surface.