Hovercraft

For stability reasons, the air is typically blown through slots or holes around the outside of a disk- or oval-shaped platform, giving most hovercraft a characteristic rounded-rectangle shape.

[7] The shipbuilder John Isaac Thornycroft patented an early design for an air cushion ship / hovercraft in the 1870s, but suitable, powerful, engines were not available until the 20th century.

It never saw actual combat, however, and as the war progressed it was eventually scrapped due to a lack of interest and perceived need, and its engines returned to the air force.

[10][11] In 1929, Andrew Kucher of Ford began experimenting with the Levapad concept, metal disks with pressurized air blown through a hole in the centre.

By the 1950s, Ford showed a number of toy models of cars using the system, but mainly proposed its use as a replacement for wheels on trains, with the Levapads running close to the surface of existing rails.

[12] In 1931, Finnish aero engineer Toivo J. Kaario began designing a developed version of a vessel using an air cushion and built a prototype Pintaliitäjä ('Surface Glider'), in 1937.

[16] In April 1958, Ford engineers demonstrated the Glide-air, a one-metre (three-foot) model of a wheel-less vehicle that speeds on a thin film of air only 76.2 μm (3⁄1000 of an inch) above its tabletop roadbed.

An article in Modern Mechanix quoted Andrew A. Kucher, Ford's vice president in charge of Engineering and Research noting "We look upon Glide-air as a new form of high-speed land transportation, probably in the field of rail surface travel, for fast trips of distances of up to about 1,600 kilometres (1,000 mi)".

[22] [23] In August 1961, Popular Science reported on the Aeromobile 35B, an air-cushion vehicle (ACV) that was invented by William R. Bertelsen and was envisioned to revolutionise the transportation system, with personal hovering self-driving cars that could speed up to 2,400 km/h (1,500 mph).

Cockerell came across the key concept in his design when studying the ring of airflow when high-pressure air was blown into the annular area between two concentric tin cans (one coffee and the other from cat food) and a hairdryer.

In December 1959, the Duke of Edinburgh visited Saunders-Roe at East Cowes and persuaded the chief test-pilot, Commander Peter Lamb, to allow him to take over the SR.N1's controls.

Through these improvements, the hovercraft became an effective transport system for high-speed service on water and land, leading to widespread developments for military vehicles, search and rescue, and commercial operations.

On flat surfaces, like pavement, the required air pressure was so low that hovercraft were able to compete in energy terms with conventional systems like steel wheels.

The first passenger-carrying hovercraft to enter service was the Vickers VA-3, which, in the summer of 1962, carried passengers regularly along the north Wales coast from Moreton, Merseyside, to Rhyl.

The service ceased on 1 October 2000 after 32 years, due to competition with traditional ferries, catamarans, the disappearance of duty-free shopping within the EU, the advancing age of the SR.N4 hovercraft, and the opening of the Channel Tunnel.

Although developed elsewhere in the world for both civil and military purposes, except for the Solent Ryde-to-Southsea crossing, hovercraft disappeared from the coastline of Britain until a range of Griffon Hoverwork were bought by the Royal National Lifeboat Institution.

In 1998, the US Postal Service began using the British built Hoverwork AP1-88 to haul mail, freight, and passengers from Bethel, Alaska, to and from eight small villages along the Kuskokwim River.

Designated 'Suna-X', it is used as a high-speed ferry for up to 47 passengers and 47,500 pounds (21,500 kg) of freight serving the remote Alaskan villages of King Cove and Cold Bay.

[citation needed] They can also be chartered for a wide variety of uses including inspections of shallow bed offshore wind farms and VIP or passenger use.

It proved an extremely successful design for a littoral fast attack craft, but due to fiscal reasons and doctrinal change in the Navy, the hovercraft was soon withdrawn.

They were deployed on trial to the Vietnam War by the United States Navy as PACV patrol craft in the Mekong Delta where their mobility and speed was unique.

Just like their full size counterparts, the ability of these small personal hovercraft to safely cross all types of terrain, (e.g. water, sandbanks, swamps, ice, etc.)

and reach places often inaccessible by any other type of craft, makes them suitable for a number of roles, such as survey work and patrol and rescue duties in addition to personal leisure use.

[61] A real benefit of air cushion vehicles in moving heavy loads over difficult terrain, such as swamps, was overlooked by the excitement of the British Government funding to develop high-speed hovercraft.

The slow speed and large mono chamber of the hover barge actually helps reduce the effect of wave action, giving a very smooth ride.

[63][64] Several attempts have been made to adopt air cushion technology for use in fixed track systems, in order to use the lower frictional forces for delivering high speeds.

The project was abandoned in 1977 due to lack of funding, the death of its lead engineer and the adoption of the TGV by the French government as its high-speed ground transport solution.

[67] Heseltine was accused by Airey Neave and others of misleading the House of Commons when he stated that the government was still considering giving financial support to the Hovertrain, when the decision to pull the plug had already been taken by the Cabinet.

In the late 1960s and early 1970s, the U.S. Department of Transport's Urban Mass Transit Administration (UMTA) funded several hovertrain projects, which were known as Tracked Air Cushion Vehicles or TACVs.

They were not especially good as vacuum cleaners as the air escaping from under the cushion blew uncollected dust in all directions, nor as hovercraft as their lack of a skirt meant that they only hovered effectively over a smooth surface.