RUBBER RULES THE WAVES

Evening Star, Issue 25676, 27 December 1945, Page 8

RUBBER RULES THE WAVES

HUGE PNEiJMATIC PONTOONS A returned serviceman from England who visited a recent war exhibition staged by the Dunlop Company-'in London, states that it convoyed a great impression as to the tremendous .wartime effort by that organisation’s • .30 factories, and the part played by. rubber in securing victory. In all, 400 different products of a wide and varied nature were displayed—these representing about half of those for which the concern was responsible. One of the most startling of the objects shown was the Admiralty Pneumatic Wave-controller—of which a miniature model was displayed. This wave-controller is the largest individual inflatable device ever produced by the rubber industry anywhere in the world. Obviously waves cannot be stopped or prevented—a fact that caused anxiety when plans were being formulated for the Allied Normandy landing on the French coast. It appears that one day a sailor arrived in London with an idea about how to control waves, which at first was regarded as fantastic. It was to take the wave in hand before it could do any damage, and gradually “ tame ” it. Eventually, the sailor’s idea, after tests had proved its worth, was adopted and tlm job of constructing the novel device was taken in hand bv the Dunlop Company. The plan embraced the making of a number of huge pneumatic pontoons each 200 ft long, 25ft high, and 25ft wide, and weighing nearly 11 tons each. The pontoon was built up in four airtight chambers—the outer chamber being inflated to a pressure of

lib per square inch; the second to 2lb; the third to 31b and the fourth to 41b—each chamber having a capacity of 7,000 cubic feet, and having to maintain its individual pressure for at least seven days. The base of each pontoon was attached with 500 bolts and channel irons to a 700tons concrete keel, faced with a metal flange. Provision was made for anchorage to the sea-bed at the end of each pontoon. A number of these units was sot in line broadside at the Normandy landing. with gaps left to admit landing craft. 'The device proved an unqualified success, reducing six-foot waves to no higher than one foot. It was revealed at the show that, during the blitzing of Great Britain, large barrage balloons left one of the company’s factories every 18 working minutes. At first, it took 3,500 manhours to produce one balloon; at the peak of the output, it took only 500 hours.

No fewer than 25 different types of tyres were displayed, ranging from huge pnuematics for aircraft and howitzer wheels to the minjtature tyres fitted to the wheels of folding bicycles as used by paratroops. Some of the big tyros displayed weighed 17 times more than a normal car tyre, and required 45 times ns much labour t.o make.