Shh ... it's an ekranoplan, isn't it?

[whole diary]

[stuving]

BBC^» (British Broadcasting Corporation - home page) South news (Paul Clifton) was doing a piece about Brittany Ferries planning to use ground effect craft called seagliders (not meant as a proper name, though BF^▸ (Brake First (carriage)) used it as such). This is apparently going to give them a route to decarbonise, while also going much faster - scarily so, at 180 mph! This is from BBC Hampshire & IoW:

Cross-Channel 'flying ferries' concept revealed for Portsmouth route

"Flying ferries" could soon be crossing the English Channel as part of radical new plans.

Brittany Ferries said its proposed craft "foils like a hydrofoil, hovers like a hovercraft and flies like a plane... with the comfort and convenience of a ferry".

The all-electric, sea-skimming gliders are set to travel from Portsmouth to Cherbourg in 40 minutes.

The 150-capacity craft could be ready for commercial passengers by 2025.

The zero-emission vehicles, developed in the United States by Boston-based start-up Regional Electric Ground Effect Naval Transport (Regent), are expected to travel at speeds of up to 180 mph (290 kph).

They will be about six times faster than conventional ferries, with a battery range of about 180 miles (290 km).
Sea-skimming Sea Glidersimage copyrightBrittany Ferries/Regent
image captionThe sea gliders will be about six times faster than conventional ferries

They rise on foils following their departure from a port, before taking off and riding a cushion of air a few metres above the water's surface for the rest of the journey.

My immediate thought was that the Russians have been making the things for decades, with the name (again, common) ekranoplan. But neither REGENT nor BF want to mention that. The BBC mention just one of them, but not that many designs were built of several subtypes.

The hints from the Russian experience are that these things pose a difficult hull design problem (which modern theory and simulation could perhaps overcome), take huge power to reach lift-off speed, and that they don't like big waves, for a variety of reasons. And 180 mph at that height, across the channel? There's a lot more that needs to not be bumped into there than on the Caspian Sea!

[eXPassenger]

My first thought was to check the date.

[grahame]

My first thought was to check the date.

Mine too - but it is a genuine effect - https://en.wikipedia.org/wiki/Ground_effect_(aerodynamics).  Perhaps this is why the Spruce Goose managed to take off but not gain much elevation?

If this were to come about, would we see the old seaplane stations being re-opened?

[eightonedee]

If this were to come about, would we see the old seaplane stations being re-opened?

...and would a proposal to extend the Fawley branch to a re-opened Calshot help the case for its re-opening?

[TonyK]

Once upolly tito, these were described as "ground effect vehicles", because they rely upon, well, the ground effect. I experienced this to the best when learning how to land a light aircraft without flaps. At roughly the height of the width of the wings, an aircraft tends to float on a cushion of air forced down by the wings, then up by the floor. Without the flaps to disrupt it, the little Cherokee I was learning to fly didn't seem to want to land, floating gracefully along the runway as I lifted the nose gently to lose speed.  This isn't an accurate description of the aerodynamics involved, but works as a simple illustration. It is very good fun, although it probably isn't in a big plane in an emergency. Helicopters experience a similar effect, but with differing results.

The effect has been known almost since powered flight began. The wing operates more efficiently in ground effect, and there is a lot less friction to overcome. The US, with German engineers,  and the Soviet Union did a lot of research in the 1960s with an eye to the military, but only the Soviets took it forward in a big way, getting to choose the name. They knew ground effect as "screen effect", and I am told that ekran is screen in Russian, like écran in French. So it's a "screen plane".

I believe the tricky bit is the transition from surface to just above surface, but that once that is cracked, it works well. I've never been one one, so don't take my word for it. Rough seas are a problem, but they are for hovercraft, which I can verify from personal experience.

[WSW Frome]

There have been a number of internet posts/articles on the former Soviet projects on ekranoplans over the past 6-12 months. These can be located by Mr Google. These were prompted by the movement of the last surviving large example from a military base to a museum close to the city of Makhachkala in Dagestan (Russia) on the Caspian Sea. They had trouble bringing the craft onshore and it was stuck on the beach for a while. Let us hope they succeeded eventually.

Some of these articles also covered the smaller type craft where some work still seems ongoing in Russia on a more commercial basis. Such work is/was done on inland waterways and promoted by the main "designer" of this type of craft.

[Bmblbzzz]

Interesting. Have vaguely heard of it under the Russian name but not understood (even vaguely) how it works until now (which I do very vaguely). As for the idea of crossing the Channel at 180mph, when they say it would be six times faster than current ferries, is this meant to imply those ferries travel at 30mph? Or simply that in practice the ekranoplan would be sixt times faster but not that at it would actually travel at 180mph (so maybe the ferries do 15 and it would do 90, for instance)?