Ekranoplan: The Airplane-Ship Hybrid
During the Cold War, around 1960s, Nikita Sergeyevich Khrushchev (the premier of the Soviet Union at that time) boasted off in front of the Western nations by announcing that his nation has ships that could jump over the bridges.
At that time, Russian engineers, led by Rostislav Alexeyev, were developing a hybrid version of aircrafts and ships that used “Ground Effect” as its major working principle. This hybrid vehicle was named “Ekranoplan” (roughly translating to mean for “screen plane” or “low flying plane”). These types of vehicles are also known as Ground-effective Vehicles (GEVs), Wing-in-ground-effect (WIG), Ground-effect crafts, Screen planes, and Wing ships, etc.
Ground Effect is a phenomenon where the air gets compressed due to the wing’s proximity with the ground and that leads to the creation of an air cushion under the wings. This results in a reduction of the aircraft’s drag and at the same time, produces additional lift. To achieve this effect, Russian engineers developed a type of under-water set of wings and configured them on the upper portion of the ships.
Ekranoplans were conceptually an improvement over then existing hydrofoils, wherein the under-water wings were removed and fixed on the upper section of the ship. When the Ekranoplan was made to run at sufficient speeds, these wings lead the vehicle to be lifted above the water due to the Ground Effect. This design, in turn, not only lead to the reduction of friction caused by the water on the ships, but also allowed this hybrid vehicle to hover over the water.
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The Tech Behind the Machine
- The first ever Ekranoplan, namely Korabl Maket (KM), was tested by the Soviet Union in the Caspian Sea during the Cold war in 1966. The KM Ekranoplan was famously known as the “Caspian Sea Monster”. During its production, its fuselage, wings, and other parts were transported separately over a span of one month to the testing site. The vehicle was assembled but this assembled vehicle was a failed attempt as it was unable to fly. However, it acted as the first ever prototype of Ekranoplan for the future manufactured Ekranoplans.
· In 1972, “Orlyonok”, aka the A-90, was introduced by Rostislav Alexeyev that was an amphibious version of the ground effect vehicle. It was able to cover the Caspian Sea from one end to the other in around 1 hour and could accommodate 200 fully armed marines along with two floating tanks (APC, IFV) and their crews on board. It had the ability to hover around 200 meters above the water surface.
- With the advancements in the technology, in 1975, a first ever Missile-carrying ground effect vehicle was introduced. It was called the “Lun” (also called Project 903) that was designed by Rostislav Evgenievich Alexeyev with the help of aircraft designer Nikolai Kuznetsov.
This beast of a vehicle could reach speeds of around 500 km/h and had a range of around 2000 kms. Lun’s maximum take-off weight was 380 tons and was equipped with eight NK-87 gas turbine engines to help achieve its flight. Lun was also fitted with six Soviet “Mosquito” anti-ship missiles (the most modern and advanced missiles in the world at that time).
Although they were called Mosquitoes, but they were quite fast and could travel at supersonic speeds (2,500 km per hour). These missiles could travel fairly close to the sea surface (around 5-7 meters above the sea surface). Its ability to travel close to the sea surface made them difficult to detected and intercepted by anti-missile installations. Only a single Lun was ever developed and though it was a beast of an invention for battle combats, it was only floated out once on July 16, 1986, and had been lying stranded off at a beach in the Caspian Sea since then.
- Another GEV named Spasatel, similar to Lun, was produced. It had similar configuration to the Lun but had a reinforced spine and an observation deck installed near its tail. It was, in a way, an improvement over the Lun. It was originally built for combat purposes but was later repurposed as ambulance vehicle. It could fly at height around 500 meters above the water and had a range of around 3000 km. It had the ability to carry upto 500 passengers and could also work as a temporary holding place to accommodate around 800 people, for upto 5 days, waiting to be rescued. It had the ability to hospitalize 80 people at once and to treat them.
- Chaika A-050, a modern Ekranoplan, is being developed by Russia which is in testing stage and is expected to be launched in 2022. It will be able to run at top speed of upto 450km/h above water, ice, and any other plane surface. It will have a range of about 5000 km and will be able to accommodate about 100 fighter troops. It will be deployed for patrolling the Northern Sea Route, Black Sea and Caspian Sea. It will be accommodated by missiles and will be capable of getting equipped with foreign technology. “India has BrahMos cruise missiles and our GEV can be equipped with them”, as said by Russian Government Personnel.
The different phases of Ekranoplan production all over the world can be seen below in the timeline:
The Ekranoplan Project could not survive the change in the military top brass, the political leadership, and the global atmosphere. With the disintegration of the USSR, the project was finally put to rest as it was now deemed expensive and unnecessary.
Types of Wing Configurations
The working of an Ekranoplan is based on the wing configuration and its placement. Ekranoplans can be equipped with different types of wings having different configurations. Some of them are as follows:
These are the types of wings that are in contact with the ground at its trailing edge. The air gets rammed into the closed cavity of the wings and increases the pressure. These types of wings have a small span wing of low aspect ratio. These types of wings are usually straight of zero taper, and tail with large area. The tail acts to stabilize the craft at different heights above the ground.
Reverse–Delta Wings were developed by Alexander Lippisch. These types of wings are configured such that the platform of the craft have wings with low aspect ratio and the wings are anhedral and have forward sweep. Its tail has a lesser area as compared to the ram wings. These wings allow stable flight in ground-effect through self-stabilization.
Tandem Wings have two wings where one wing is positioned behind the other. The crafts with these types of wings had limited stability, low seaworthiness, and high take-off speeds. Tandem Wings can have three types of configurations: –
- A biplane-style: Biplane style has a shoulder-mounted main lift wing & belly mounted sponsons similar to those on combat and transport helicopters.
- A canard-style: This type of configuration comprises mid-size horizontal wing near the nose of the craft resulting in airflow under the main lift airfoil and, in turn, reducing the water drag.
- Two stubby wings: In this type of configuration, two short and thick wings are devised such that the design leads to a self-stabilizing craft longitudinally. This configuration produced by Günther Jörg in Germany in tandem-airfoil flairboat.
Benefits of Ekranoplans:
- Ekranoplans can get undetected by enemies’ RADARs because of low altitude above the water.
- Transportation of military goods and cargo over the oceans is easy and quick.
- High Running Speeds.
- Equipped with Missiles for Combat operations.
- Missiles equipped on Ekranoplans can be launched from a distance.
- Underwater torpedoes and naval mines can be avoided.
- Useful for Marine Patrolling.
- Low chances of fatal damage in case of engine failure as the vehicle is close to water.
- Effective for use at shallow coastlines.
- GEVs can cover long range of distance.
- It can travel over ice, land, sand etc. once in hovering stage.
- It can act as ambulance vehicle over the water bodies.
Limitations of Ekranoplans:
- Limited altitudes of flying.
- Difficult to land back in water due to water’s instability.
- It is hard to operate Ekranoplans in harsh weathers and sea tides.
- Difficult to avoid any sudden obstacle due to low altitudes.
- Engine noise makes it easy to detect.
- Can be easily targeted by enemy vehicles once detected.
- High maintenance costs.
Reasons of halt in Ekranoplan production:
Ekranoplans were introduced by Soviet Union in the year 1966 and were used till early 1990s. Some developments and improvements were made to introduce new models of Ekranoplans over this period. However their use and production was halted by the Russian Government due to its unusability at the time. Some of the reasons for the same are as follows:
- A patriot park is being built in Derbent, in Russia’s republic of Dagestan. It will have a military museum and theme park and will be used to display different Soviet and Russian military equipments used during the Cold war and other Combat operations. Lun is expected to be moved to the park for the display at the park.
- RDC Aqualines have announced that they will be manufacturing an Ekranoplan named “AQUAS”. Aquas will be a clean energy operable vessel and will be 100% electric and hydrogen hybrid vehicle. It is expected to run at high speed and carry 14 people (12 passengers, and 2 crew members) from one point to the other. It is expected to be launched for use in 2024 for travelling at high speeds with advanced safety and comfort.
- Iran has bought 6 Ekranoplans named Orion-20 from Russia in 2020. It has a maximum speed of 180 km/h and can haul upto one tonne of cargo and accommodate 12 passengers along with the cargo.
- Aquila Global Inc. is developing Ekranoplans, named AQUILA GLOBAL AG12, which will have a top speed of 250 km/h that will be able to cover around 1200 miles in 5hrs.
- Flying Ship is a U.S. based start-up that has planned to use Ekranoplan based concept to produce unmanned vehicles to utilize them for maritime logistics.
- DARPA (Defense Advanced Research Projects Agency) is a research and development agency of the United States Department of Defense that has developed “Liberty Lifter”, an advanced version of Soviet Ekranoplan, that can transport people and cargo over the water.