A bizarre cross between a hovercraft and an airplane,
developed during Cold War
They hover and skim above the water surface at speeds of up to 250 miles an hour, they carry heavier loads of cargo and troops than any airplane - the Ekranoplans, or "Wing-in-Ground" (WIG) vehicles are possibly the most exciting and strange looking technology ever designed by men.
Developed mostly by Soviets during Cold Wars years (by Rostislav Alexeev's design firm) some of them were over 500 feet in length and had an estimated weight of over 500 tons! And yet they skimmed over the waves with grace, at high speeds, able to negotiate stormy conditions, unseen by radar - all thanks to an aerodynamic principle known as the "ground effect".
All pilots are familiar with this effect: when an airplane is about to land, it almost wants to "float" on air, moments before touchdown. The compressed air between the wing and the ground becomes a "cushion" that gives the plane smooth gliding ability. Over the sea surface this effect is even more noticeable.
1. KM - Russian "Caspian Sea Monster" Ekranoplan
It was the biggest ground-effect vehicle ever designed (100 meters long, weight: 544 tons, powered by ten Dobryin VD-7 turbojet engines). It still holds the record for lifting the heaviest load off the ground (more even than the largest modern cargo plane Antonov An 225 "Mriya" can handle). It also had an air of mystery around it for a long time, tested in secrecy on the Caspian Sea in 1966 and spied on by a US satellite.
Although only one KM (Russian abbreviation for prototype ship) has been built, there were several variations, differing in length and weight. All were intimidating and weird looking, designed to use the ground effect to skim the ocean at high speed, undetected by radar. According to military sources, the Soviet government planned to built 100 of these monsters at the height of Cold War, then the number went down to 24.
(Images source: The WIG Page and Samolet)
After an accidental crash (due mostly to poor visibility in the fog), KM was abandoned in a shallow 20 meters of water, thwarting all efforts to recover it because of its weight; its high tail sticking out of the water like a funeral cross.
The next model to take its place will be "Orlenok" - a medium-sized ekranoplan suitable for military transportation duties.
SM-8 (smaller version of KM).
2. An Impressive A-90 "Orlyonok" ("Eaglet")
"The 140 tonne, 58 meter long aircraft had its maiden flight in 1972. The A-90 boasted two turbojets and one turboprop engine which propelled it to a speed of 400 km/h for 1,500 km at an cruise altitude of 5-10 m."
It could travel over land, if need be, and in rather spectacular fashion:
(images credit: A. Belyaev, The WIG Page)
It could carry 150 troops and 2 tanks (or rather, BTR-60), as evidenced by this picture:
(image credit: Airforce.ru)
The Soviet military planned to built 20 such vehicles, creating a whole new division in the Baltic Sea. The aircraft has been supplied to the military in 1979, and three A-90s reportedly were still operational in 1993. However, a couple of crashes prevented the full deployment; one crash was especially spectacular. The craft lost a whole tail section after striking a wave, but proved to be air-worthy enough to make it "gliding" to the shore. This amazing feat still did not impress the generals enough, and the program was mothballed.
UPDATE: "Since the collapse of the Soviet Union, the plant responsible for building the Orlyonoks has been privatised. Now called the Volga Shipyard, the Orlyonok is apparently still being developed as a commercial search and rescue craft. In fact, it appears that the Orlyonok can be ordered in either cargo-carrying (50 tons with a 1500km range) or in passenger carrying (30 people and a 3000km range) versions - the yard lists it as a production model!" (source)
3. Strange intermediate designs: VVA-14M
"VVA-14M" ekranoplan was essentially a conversion from the very strange-looking plane "VVA-14". Here it's seen before the conversion:
and after, cruising over water:
(image credit: Ronald Wong, The WIG Page)
4. "Lun (Spasatel)" (1987) - bigger than KM "Sea Monster" and way more dangerous!
"The 280 tonne, 74 metre long M-160 Lun was another ekranoplan developed from Alexeev designs. One was built in 1987, which entered service in 1989."
(image courtesy: Paul McDonell)
It's actually bigger than Boeing 747!
(image credit: Peter C Losi - United States Air Force)
What's more, it was equipped with unparalleled to this day ZM-80 "Moskit" (SS-N-22 Sunburn) supersonic rockets, capable of sinking any enemy ship. This machine would've been a formidable threat to NATO if not for the sudden collapse of the Soviet Union. Insufficient funds for continuation of research and the overall decline had sunk this project altogether, even though some efforts have been made to convert "Lun / Spasatel" into a sea rescue vessel.
(images source: Airwar.ru)
Here is the "Spasatel" civilian version:
Another interesting concept which almost made it into production:
All these and other variations of Russian ekranoplans you can see in this long video (10 minutes of great & rare footage):
That video also shows the current sad condition of Russian giant "Lun" craft, stored at the Kaspiysk naval base... Maybe some kind of a "crazy scientist" or an investor will turn out on eBay, pay the minimum bid and put this thing to use again??
The "swan song" of Rostislav Alexeev, the last considered concept was the "Rocket-2" river cruise ship design:
(art by A. Sukhov, courtesy rosevg.org)
Steven Hooker, an aeronautical engineer, first observed the Caspian Monster in 1967 and went on to establish the "Aerocon" company - with a dream of making "wingship" ten times bigger, and truly trans-oceanic in range. Here is the proposed Aerocon Wingship concept from 1984:
(it is the size of twelve Boeing 747's !)
"Atlantis - 1":
Image courtesy: Popular Science
It still remains to be seen whether this gargantuan ship is going to be built; but for now US NAVY is considering another prototype:
Boeing Ultra Pelican -
American (belated) answer to the "Caspian Sea Monster"
Look at the size of that conceptual boat, or rather "Large Transport Aircraft" - it can easily carry 1,400 tons (as many as 17 tanks plus a few hundred soldiers) to distances over 16,000 km. This spectacular machine will have wingspan of 106 meters (about 350 feet) and length of 152 meters (longer than a football field). The craft would be 10 times faster than any modern container ship.
"The vessel will be able to travel in ground-effect at a height of about 20 feet above the water surface for its most economical mode of operation, but will also be capable of entering free-flight and flying at an altitude of 20,000 feet."
Sources: foxxaero, Popular Science, Boeing
If this craft's development proceeds unimpeded, then the military dream of "deployment of one division in five days anywhere in the world" would be realized. You can run but you can't hide. The Wingship's potential for strategic lift is almost unlimited. What's more, its operating efficiency (delivering cargo per consumed fuel) is 44% better than modern cargo airplanes!
Wingship is an achievable technology, and even if a smaller but successful prototype will be built (perhaps with Russian / American cooperation?) - it might open a new era in transportation, the exciting blend of sea and air travel. For now, we only see larger and larger cruise ships and airliners being built, without much consideration for operating efficiency.
The best web resource available about WIG craft is The WIG Page. See many models there, and some most unusual concepts.