The Russian Ekranoplan looks like an aircraft
but it only flies a few metres above water. Translated the Russian
name Ekranoplan means sea skimmer and this is exactly what the
Ekranoplan does. The Ekranoplan is what is known as a Ground
Effect Vehicle, it operates on the principle of wing in ground
effect, where the air gap between a wing and the ground is small
enough for the air to be compressed.
Born out of the Soviet Unions Central Hydrofoil Design Bureau it
was developed by their chief designer Rostislav Alekseev. Several
different Ekranoplan's were developed from 1961 to 1990. Since the
fall of the Soviet Union many of the design team from the CHDB
have formed a new company with plans to develop new craft for
passenger and cargo usage. Also 11 small 5 passenger craft were
constructed between 1995 and 1997, they were used in trial
commercial operation in USA and the Bahamas.
The benefit of Ground Effect Vehicles is they can carry very heavy
payloads economically at fast speeds. This is one of the reasons
the former Soviet Union invested in their development as they were
military benefit, one added bonus in flying low just above the
water is they can keep below enemy radar. The largest Ekranoplan
could transport over 100 tonnes of cargo and would use less fuel
to cover the same distance of an aeroplane at the same speed.
The largest Ekranoplan called the KM was built in 1967, it was
dubbed the Caspian Sea Monster after the sea it was on when first
seen by the west. It was almost twice the length of a Boeing
777-200 but as with all Ground Effect Craft it need only half the
wingspan. At over 100 m long, weighing 540 tons fully loaded, the
KM could travel over 400 km/h mere meters above the surface of the
water. Once moving at speed, the Ekranoplan was no longer in
contact with the water, and could move over ice, snow, or level
land with equal ease.
The important design principle is that the wing lift reduces the
further above the surface of land or sea that the ekranoplan
"flies". Thus its dynamically stable in the vertical dimension.
These craft were originally developed by the Soviet Union as very
high-speed (several hundred km/hour) military transports, and were
mostly based on the shores of the Caspian Sea and Black Sea. The
could transport over 100 tonnes of cargo.
The term ground effect vehicle is often misapplied to
hovercrafts, which use
fans to form an air cushion (hence the correct term air cushion
vehicle) rather than relying on true ground effect. they are also
confused with hydrofoils which were also developed by the same
Russian design Bureau. Similar in operation, Hydrofoils are more
like a boat with wings that sit in the water, it makes the
Hydrofoil look like a boat on ski's.
Concorde was not the only
supersonic commercial jet, the Russian
Tupolev TU-144 was a copy of
Concorde and its first flight was 3 months prior to the
Concorde. After many problems and several crashes it
stopped service in 1985.