Ground effect

[Willallison]

Not new - but surely this is taking things to a whole new level....

http://www.******************/Designe...Ekranoplan.htm

[Jeff]

Wow - talk about thinking outside the box... and large projects!

244' (74m) Ultra Fast Superyacht Ekranoplan

Designed by: CHDB
$75,000,000 (US)
Cruising speed - 450-500 km/h (250 Knots)
Range - 4000 km
Cruising flight height - 1 to 4 m
Sightseeing flight height - 100-300 m
Seaworthiness:
in flight - no limitations;
when landing - up to 3.5 m (3% occurrence);
when taking off - up to 2.5 m (3% occurrence)
Take off weight - up to 400 t
Length overall - 73.8 m
Breadth overall - 44.0 m
Height overall - 19.2 m
Hullborne draft - 2.5 m
Fuel stock - 80-120 t
Cargo capacity - 40 t

This is from the link posted above which shows the smaller ground effect 40' Islander and rendered views of the 192' Gemini.

[Willallison]

project for "Option Two" do you think...?

[fishboat]

If you're looking for something new, look to something old. The Russians developed a similar, though MUCH larger, ground-effect craft like this back in the 50's or 60's. Though it seemed to work, the changing times & leadership switched direction & the long-term use of the craft never got off the ground..so to speak.

[FRANKIEFRANKIE]

Check the Schoellmarine.com web site for the patent he holds. It is being built currently in NJ.

[Mike D]

Try this site
http://foxxaero.homestead.com/

It shows the original Russian WIG and also has links to other avant-garde designs

Michael

[fishboat]

Mike,
That's the one. I saw film of it being tested sometime back. Talk about a 'boat' kicking up a fuss on the water...whew. This craft was huge...it was hoped to be a secret weapon that would be key in overwhelming the US if the cold war ever went hot.

[Mike D]

Kevin

I've seen a few shows on TV about it. Aren't the senior designers now in the US?

I read extensively many of the sites on the net over a year ago and there are 1290 on Google as of a few minutes ago.


Michael

[fishboat]

Michael,
As I remember there was one specific designer that was literally the dreamer, the architect of the craft & the project head....much like the same type of project setup when the Russians copied our B29 SuperFortress and called it their TU-4. As with many Russian programs it goes forward as long as you remain in good graces with whomever is in power...as soon the head of the WIG project fell out of graces, due in part to shifted priorities in the Russian government, then the project was cancelled. I would guess the main designer on this craft is long since dead. There may be others still alive & in the US.

[tspeer]

Originally posted by fishboat
Mike,
...This craft was huge...it was hoped to be a secret weapon that would be key in overwhelming the US if the cold war ever went hot.

Actually, it was intended to transport troops across the Baltic sea for amphibious assaults on the Nordic states. It could fly above rough seas and run right up on the beach, bypassing defensive obstacles.

The Russian Ekranoplan's are built using ship-type construction. Heavy and rugged compared to the thin-skinned construction typical of most aircraft.

I once met the original inventor of the WIG, Alexander Lippish. He told me he had envisioned the WIG to be used in riverine operations, like going up the Amazon, with its ability to zoom over obstacles like fallen trees. He didn't see any need for the WIG to be able to sustain flight.

Boeing PhantomWorks in Long Beach are looking at a cross between the WIG and conventional aircraft to build a very large cargo plane (http://foxxaero.homestead.com/indrad_043.html). Unlike most WIG's this one would be land based and not capable of landing on water, and it would be capable of flying at medium altitudes (~25,000 ft). So it's really an airplane that takes advantage of ground effect, rather than a died-in-the-wool Ekranoplan. The plane will also be designed for minimum construction cost - nearly all developable surfaces, interchangeable tail surfaces, etc. Since this rendering was released, they've gone to a T tail, which makes sense because a conventional tail on a WIG is a recipe for unstable pitch-heave coupling.

[Steve Gray]

A few years ago, Channel 4 TV in the UK produced an hour-long programme (entitled 'Eukranoplan') devoted to these ground-effect craft. The last fifteen minutes was used to show modern examples as 'transports of the future', but the majority of it was given over to the historical stuff, mainly footage of the Soviet craft in action and under construction, interviews with developers and pilots--with one or two prangs included for good measure. The craft had fat, stepped hulls, V-tails and multiple, tucked-in-down-angled motor pods--so it looks like they were on the right lines.

One part showed a factory on the Black Sea, I think, where several of these huge things had been moth-balled and were still sitting there waiting to be finished; a hopeful interviewee said that maybe development, building and selling E-plans would be a good economic proposal for the new Russia--although the programme makers concluded that the market appeared to be limited to 'personal water taxi' styles, dominated by German suppliers (of course!).

Whatever, I'm glad that I taped that programme--I'll have to dig it out to watch it again.

[yipster]

http://www.se-technology.com/wig/
more wig "boats" and under theory also a airfoil calculator...
yipster

[Zanith]

I wonder how these craft would manage to be stable on a sea with fairly moderate swells.

[tspeer]

It would be much like a hydrofoil - you platform the smaller waves and contour the larger ones. What constitutes a "small" wave or a "large" one would depend on the craft and its speed.

Just like with a boat, the encounter frequency will go up as the craft goes faster. There will be some natural frequency for its heave response, and at encounter frequencies much greater than that, it will simply not respond to the waves. The effective flying height will then be relative to the mean water level, which could be a problem if the peak wave amplitude is large compared to the flying height.

For encounter frequencies less the natural frequency of the heave response, the craft could contour the waves and the ride quality would be like that of a roller coaster. Since the WIG will undoubtedly have an automatic control system, the pilot can also control the natural frequency somewhat by selecting different gains for the feedback system to get either a "hard" or "soft" ride.

The pilot would have two choices in large swells were difficult for the craft to handle. One option is to fly higher, requiring more power but maintaining speed and ride quality. The other option would be to slow down enough to follow the wave contour, which could make for a rough ride.

I suspect the ability to platform the waves will determine the limiting sea state for flying operations. I'd also expect that most practical WIG craft would be capable of flying high enough to handle some pretty severe seas. And the speed would allow you to stay away from most nasty weather systems.

[Zanith]

tspeer - Hrm. Well, even though. We do and often encounter unplanned issues and even unforseen events. But I agree.