GB1276292A - Improvements relating to gas-cushion vehicles for operation over water - Google Patents

Abstract

1276292 Gas cushion vehicles HOVERCRAFT DEVELOPMENT Ltd 27 May 1969 [26 Feb., 1968] 4194/68 Heading B7K In a gas cushion vehicle the gas-cushion is divided into compartments 3a, 3b so that initially the vehicle is supported by cushion gas which is supplied by the fan units 5, 6 and when the vehicle has passed "hump" speed the fan unit 5 is shut down, the compartment 3a now being at atmospheric pressure, and the fan units 6 are speeded up to support the vehicle by just the outer compartments 3b. The front and rear of the compartments 3a, 3b are bounded by flexible skirts (not shown). The rear skirts may be made retractable so that air can escape beneath the skirts in addition to flowing through the ducts associated with the fans 5, 6 should the waves produce a "piston" action within the compartments 3a, 3b. In another embodiment Fig. 2, the fan units 25 supply both the compartments 23a, 23b. The cushion space is bounded except for the portion between the rear ends of the wall structures 24, by a flexible skirt 22 of inflatable form with its lower end comprised of flexible wall members 39 of the form disclosed in Specification 1,043,351. Tie cords 41 connect the inner ends 40 to the vehicle body 38. The rear end of the compartment 23a is bounded by a skirt 2, Fig. 3 (not shown), of the form disclosed in Specification 1,056,267, and is inflated by way of a duct (27). After "hump" speed has been reached the skirt 26 is deflated allowing cushion air to escape from the central compartment 23a thus causing the vehicle to sink. The wall structures 24 dip into the water and isolate the outer compartments 23b on which the vehicle is supported at a higher pressure. Since cushion pressure is related to the area of the cushion, pressure changes may be moderated by lateral deflection of the flexible skirt 22, Fig. 6 (not shown). The cushion of the vehicle may be divided into more than three compartments, as well as only two compartments, provided in this case that one surrounded the other to provide a symmetrical distribution about the centre of gravity. Also the reverse arrangement to venting the compartments may be employed.