A carrier that uses a layer of compressed air (air cushion) between the lower body and the ground to support its own gravity and is also called a hovercraft or hovercraft.
The first successfully tested hovercraft was the SR.N1 hovercraft designed by the British C. Cockrell. It made its first operation in 1959. Air cushion devices are divided into two types: pressurized chamber type and peripheral air curtain type (peripheral jet).
① Pressure chamber type: The bottom of the device is like an inverted plate. Air enters the bottom through a low-pressure, high-flow centrifugal fan and forms a pressurized chamber with the ground (or water surface) to form an air cushion to float the device.
This type is widely used in sidewall hovercraft and various air cushion lifting platforms. Sidewall hovercrafts are usually propelled by underwater propellers or water jets and use water rudders to control direction. They have no amphibious capability.
② Peripheral Air Curtain Type: The air pressurized by the centrifugal fan is sprayed down and in through the small nozzles arranged evenly around the bottom to form an air curtain to reduce air leakage from the air cushion. If you add a flexible apron around the periphery, you can also increase the height of the cushion.
Amphibious hovercrafts mainly adopt this type. The air cushion device can reach a speed of 150 km/h or more, and the operation is relatively stable, which is suitable for operation in the sea, swamps and water mains areas.
In the military, air cushion devices can be used for amphibious landing, patrol, mine clearance and anti-submarine. In civilian use, it can be used for water transport, life saving, etc.