Lekov designed and built a small number of
craft during the 1930s, including the L-5 fast
attack boat that reached 130kmh in testing.
Levkov’s work can still be seen today, classed
as ground effect vehicles.
Once WWII was over, development of
air cushioned vehicles was undertaken by
several groups around the world. The Soviets
especially saw the potential and set up
the Central Hydrofoil Design Bureau, but
persisted with Levkov’s ground effect design.
Over the next 30 years the Bureau produced
a number of craft but none ever entered
production. The most famous of these
designs was the ‘Caspian Sea Monster’,
as it was nicknamed, which was a massive
missile-firing boat powered by eight jet
engines.
Meanwhile in Canada John Carver Frost,
who worked at Avro Canada, had started
experimenting with another system. His
work led to the development of the Avrocar,
which used a lift engine to blow air directly
down like modern hovercraft. But as it was
Both the US and Japanese Navy use the LCAC hovercraft
being developed for the aero industry results
were not what they were expecting, and the
project was abandoned in 1961.
It was Sir Christopher Cockerell who
really developed what we now recognise
as a hovercraft. He named the key concept
in his design the ‘momentum curtain’,
which could be used to trap high pressure
air inside the curtain to provide the lift
required based on pressure, not on airflow.
Cockerell built several models of his designs
in the early 1950s, featuring an engine
mounted to blow air from the front of the
craft into a cavity below, thus combining
both lift and propulsion. He demonstrated
this model at Whitehall and his design was
put on a secret list. Unfortunately, not one
service was interested and he received no
funding to carry on his work. The idea was
declassified and Cockerell convinced the
National Research Development Corporation
to fund development of a full scale model. In
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Xmas 2011
The Soviet Ekranoplan, better known as the Caspian Sea Monster
1958 a contract was placed with Saunders
Roe, based on the Isle of Wight, for the
development of what became known
as SR.N1. Saunders Roe Nautical 1 (SR.
N1) made its first hover on 11 June 1959,
followed by its famous crossing of the
English Channel on 25 July 1959.
American inventor Norma B McCreary is
credited with inventing and patenting the
‘Doubled Walled Flexible Skirt’, also known as
the ‘Bag Skirt’. It inflated around the edge of
the hovercraft and was a major development,
allowing the craft to move more easily over
waves and uneven or rough terrain. The
craft could be raised and lowered off the
surface by inflating or deflating the skirt.
To compensate, and reduce wear and drag,
‘Fingers’ were added later. In 1960, after
this concept was made public, all hovercraft
began to utilise the ‘Doubled Wall Flexible
Skirt’ design.
Military hovercraft
In the UK the Inter-Service Hoverc raft Trials
Unit (IHTU) was set up to test the suitability
of hovercraft for military applications. Based
at Lee-on-the-Solent (now the site of the
Hovercraft Museum), trials were carried out
on SR.N1s as well as testing the SR.N2,
SR.N3, SR.N5 and SR.N6 craft. Currently,
the Royal Marines use the Griffon 2000
TDX Class ACV operationally, which saw
deployment in Iraq.
During the 1960s in the US, Bell, under
licence, sold the SR.N5 as the Bell SK-5.
The US Navy deployed a number of these to
the Mekong Delta during the Vietnam War.
They were known as PACV patrol craft and
their speed and mobility were used to good
effect. Some were modified with a new
deck configuration featuring a gun turret and
grenade launchers. These were designated
9255 PACV. The US Army also experimented