Hovercraft Physics Hovercrafts, Also Known

Hovercraft Physics

Hovercrafts, also known as air-cushioned vehicles (ACVs), come in a variety of shapes and size, although the underlying physics are virtually the same in all models. These underlying mechanisms have been developed over time to create more efficient and better performing machines. This essay will examine the history of the hovercraft, recent developments, and possible future developments which may take place.

Hovercraft Developments

History of Hovercraft

Invention of Hovercraft

The concept of a vehicle which would be able to travel on cushions of air was first proposed back in 1877 by the English engineer John Thornycroft, although Christopher Cockerell is credited with the actual invention. Cockerell developed and built the first hovercraft in 1955 (Johnson 550). It was constructed of balsa wood and powered by a small fan, reaching speeds of up to 12 mph over both land and water. It was not until 1959 that the first practical model was built by Saunders-Roe Ltd. who were predominantly an aircraft manufacturing firm. The hovercraft then entered public use in 1962, where the first passenger hovercraft began operation across the Dee Estuary in Scotland (Sebastian 179).

Hovercraft Design

The first hovercraft developed used large fans to pump air through an annular nozzle which ran around the outside of the craft. The high pressure which is created by this method underneath the vehicle is the force which results in the craft being lifted off the ground. In order for hovering to be obtained the force created must therefore be equal to or greater than the weight of the vehicle. The height to which these early models could be lifted was therefore limited by the power which was available to create this lift. This then limited the use of the vehicles as the small lift which was achievable meant that the vehicle was able to clear only small obstacles. This problem was overcome by the addition of a skirt around the base of the vehicle to create a chamber in which the pressure could be increased without the need for additional power. This remains the basic design in hovercraft today, although the design of the skirt may range from a simple curtain to more sophisticated designs (Bourg 164).

Recent Developments

The traditional type of hovercraft which may spring immediately to mind is that such as the ones which are used in some areas as a type of passenger ferry across small stretches of water. The structures of these hovercraft, such as the design of their propellers and controls has been largely developed thanks to home-build enthusiasts, who often look for new ways of creating a better craft ("History of the Hovercraft"). Hovercraft have recently seen several developments which have widened their use however.

Heavy Load ACVs

Several hovercraft manufacturers have also now developed hoverbarges, which are designed to carry heavy freight loads across previously inaccessible terrain. This is particularly useful in areas in which there is little development in terms of roads, and where terrain may make access by road-going vehicles difficult. Examples of this may include the forested regions of Canada, where the hoverbarge may be used to carry out large loads of trees ("ACV Research and Development"). This type of hovercraft may also be particularly useful for military purposes, as often there is a need to access areas which have no roads suitable for carrying large amounts of kit and personnel.

Personal Hovercraft

There have also been recent developments in hovercraft for the consumer market. International Robotics has now developed the first personal hovercraft known as the Alura Airboard. This is designed to travel on land, not on water, and has been developed as a type of adult's leisure craft for one person ("IRI & Techno-Marketing International Technologies"). Although there may only be a limited number of individuals who own one so far it is possible that in the future these will become a popular method of travel.