hovercraft Also known as an air-cushion vehicle (ACV), a versatile marine, land, or amphibious vehicle which supports its weight on a high-pressure air cushion maintained by a system of fans. Because this minimizes the friction between the craft and the ground, the auxiliary propulsion equipment can maintain speeds up to 100 knots, even over difficult surfaces. Although the air-cushion principle was rediscovered by the British engineer Christopher Cockerell in the early 1950s, technical difficulties have so far limited the use of ACVs to military applications and ferry services on relatively short sea crossings. Ground-effect machines (GEMs) are sometimes distinguished from ACVS as, like airplanes, they derive most of their lift from their aerodynamic design and forward motion. Related category TECHNOLOGY Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) |