04/07/2013
After he left the Marconi company, they bought Ripplecraft Ltd., a small Norfolk boat and caravan hire company, with a legacy left by his father in law. The firm made little money, and Cockerell began to think how the craft could be made to go faster. He was led to earlier work by John I Thornycroft and Sons, in which a small vessel had been partially raised out of the water by a small engine.
Cockerell's greatest invention, the hovercraft, grew out of this work. It occurred to him that if the entire craft were lifted from the water, the craft would effectively have no drag. This, he conjectured, would give the craft the ability to reach an indefinite maximum speed, relative to the speed of the boats of the time.
Cockerell's theory was that instead of just pumping air under the craft, as Thornycroft had, if the air were to be instead channelled to form a narrow jet around the perimeter of the craft, the moving air would form a momentum curtain, a wall of moving air that would limit the amount of air that would leak out. This meant that the same cushion of high pressure air could be maintained by a very much smaller engine; and for the first time, a craft could be lifted completely out of the water.
He tested his theories using a vacuum cleaner and two tin cans. His hypothesis was found to have potential, but the idea took some years to develop, and he was forced to sell personal possessions in order to finance his research. By 1955, he had built a working model from balsa wood and had filed his first patent for the hovercraft, No 854211. Cockerell had found it impossible to interest the private sector in developing his idea, as both the aircraft and the ship building industries saw it as lying outside their core business. He therefore approached the British Government with a view to interesting them in possible defence applications.
The hovercraft was indeed seen to have defence potential, and so the hovercraft was classified. But the leaders of the defence groups were not interested in providing funding. It remained classified until ___, when, hearing of similar developments on the continent, declassified it. Being Harold Wilson's White Age of Technology, Cockerell was introduced to the NRDC (National Research Development Corporation).[citation needed] In the autumn of 1958, the NRDC placed an order with Saunders-Roe for the first full-scale hovercraft. This prototype craft was designated the SR-N1 (Saunders-Roe - Nautical One) and was manufactured under licence from the NRDC. On 11 June 1959, the SR-N1 was first shown to the public, which was capable of carrying four men at a speed of 28 miles per hour. Weeks later, it was shipped over to France. It successfully crossed the English Channel between Calais and Dover on 25 July 1959,[5] 50 years to the day after the historic crossing by Bleriot.
In January 1959, the NRDC formed a subsidiary called Hovercraft Development Ltd. Cockerell was the Technical Director and the company controlled the patents which it used to license several private sector firms to manufacture craft under the registered trademark of Hovercraft.[citation needed]
In later life, Cockerell developed many other improvements to the hovercraft, and invented various other applications for the air cushion principle, such as the hovertrain.
He attended many hovercraft related events, such as the unveiling of many hoverports across the United Kingdom.
