British Hovercraft: Saunders-Roe, BHC, Griffon, Vosper, Vickers etc...

[Weaver]

All of the points raised make it clear why all of the proposed long-range, blue-water ACVs
of various sorts came to nowt.
Operating a fully cushioned craft out in the open sea was
always questionable, which is Cockerell himself proposed the
sidewall hovercraft the rigid sidewalls increasing stability and making it less sensitive
to the vagaries of the weather.
Denny, Hovermarine and Bell all built sidewall hovercaft using Cockerell's basic concept.
Now I wonder if I have anything on sidewall hovercraft and surface effect ships?
🤔
😉

It's not just how stable it is, it's also how sturdy it's construction is. The SR.N4s were built like aeroplanes, not ships, with a lightweight "eggshell" structure. The one that got damaged in 1978 and another that had a collision show just how fragile that could be. Later hovercraft didn't just switch to marine diesel engines for economy, they also switched to more ship-like construction techniques, both to save money and to increase sturdiness.

[NARSES2]

A hovercraft facing a severe weather warning in front of it would likely be better off running for the nearest shore and waiting it out on the beach.

So it's not an ocean going vessel then ? So if you needed them in the Persian Gulf say they'd have to have safe ports of call either all the way around the coast of Africa or the Mediterranean and Suez ? Theorecticaly doable in the Age of Empire I suppose but post that ?

Fascinating concept though. Travelled on one a couple of times, but always preffered the ferry.

[Weaver]

A hovercraft facing a severe weather warning in front of it would likely be better off running for the nearest shore and waiting it out on the beach.

So it's not an ocean going vessel then ? So if you needed them in the Persian Gulf say they'd have to have safe ports of call either all the way around the coast of Africa or the Mediterranean and Suez ? Theorecticaly doable in the Age of Empire I suppose but post that ?

Fascinating concept though. Travelled on one a couple of times, but always preffered the ferry.

Well either that, or they go there on a heavy lift ship, as per the subsequent discussion.

If they had to "hop" to the Gulf in 1991, it'd probably be doable. There's friendly ports/stops all along the north of the Med, then Cyprus to Suez, then around the Arabian peninsular and into the Gulf. The trick would be organising the right fuel and supplies to meet them, but that should be doable too. All quite the epic effort though.

What I'm tending towards is that the RN buys a split fleet of fewer Hunts, plus, say, four hovercraft and maybe a tender/heavy-lifter as a large-scale experiment. They send the hovercraft to the Gulf, not because it's the purely best option, but because it's the first opportunity to test them in a real war. The argument from the hovercraft unit is that although it's a pain getting them there, once in-theatre they can operate from a random beach (or their lifter/tender) rather than overcrowded port facilities. It's analogous to the argument for USMC Harriers operating from a FOL on the coast road, rather than overcrowded airbases.

[PR19_Kit]

Not sure they'd need to worry about the Suez Canal, the could just zap across the desert if need be. 

[Weaver]

Not sure they'd need to worry about the Suez Canal, the could just zap across the desert if need be. 

Saudi Arabia's not as flat as people imagine. There's quite a few mountain ranges and even the desert has steep dunes. You'd have to very carefully survey a route to make sure a big hovercraft wouldn't get stuck. Also, how much sand can the engines eat? No point getting there with clapped-out engines, and sand filters would take time to design, test, and build.

[Rick Lowe]

If the US experience in Vietnam is anything to go by, the operating co$ts would be huge (back then, around $1 million per unit per year *in 1965 Dollars!*) and they'd be heard coming for literally miles.
So not a stealthy option...
But if you're setting off mines anyway, that's academic...

And this is WhiffWorld, after all...  and they're in the middle of an area filled with oil fields...

[Weaver]

If the US experience in Vietnam is anything to go by, the operating co$ts would be huge (back then, around $1 million per unit per year *in 1965 Dollars!*) and they'd be heard coming for literally miles.
So not a stealthy option...
But if you're setting off mines anyway, that's academic...

And this is WhiffWorld, after all...  and they're in the middle of an area filled with oil fields...

According to DK Brown they had great difficulty working out the costings despite trying many different methods. The overall conclusion was that the purchase price was much cheaper than a conventional GRP-hull minesweeper* and the running costs were higher, but not as high as US-style helicopters. They thought the through-life cost of the hovercraft would work out less than the displacement hulls, but obviously that would be dependent on how intensely they were used, and how much damage/refit cost they incurred.

The sound signature underwater, where it mattered, was actually as low as a conventional minesweeper, but without needing elaborate shielding, rafting or silencing, hence (partly) why the hovercraft were cheaper to buy.

Re "oil country", yeah, it has to be significant that the only customer for combat hovercraft (handful of BH.7s) was pre-revolutionary Iran...

*Large GRP hulls are well understood now, but the RN's Hunt class were the pioneers and they were fantastically expensive for their size. When frigate/destroyer crews used to take the mickey out of minesweepers as "cute little toy boats", the Hunt crews' retort was that their ships cost more per foot than the "proper" warships...    

[PR19_Kit]

One of the primary 'running costs' of operational hovercraft was replacing the skirts frequently as they wore out quite rapidly.

Even during the short time I worked on them, a bit more than a week, they'd replaced some segments of the skirts on 'The Princess Margaret' during its time at Dover hoverport.

[NARSES2]

If they had to "hop" to the Gulf in 1991, it'd probably be doable. There's friendly ports/stops all along the north of the Med, then Cyprus to Suez, then around the Arabian peninsular and into the Gulf. The trick would be organising the right fuel and supplies to meet them, but that should be doable too. All quite the epic effort though.

What I'm tending towards is that the RN buys a split fleet of fewer Hunts, plus, say, four hovercraft and maybe a tender/heavy-lifter as a large-scale experiment. They send the hovercraft to the Gulf, not because it's the purely best option, but because it's the first opportunity to test them in a real war. The argument from the hovercraft unit is that although it's a pain getting them there, once in-theatre they can operate from a random beach (or their lifter/tender) rather than overcrowded port facilities. It's analogous to the argument for USMC Harriers operating from a FOL on the coast road, rather than overcrowded airbases.

Right    Rather as I thought. It would be an interesting example of a nation saying "Look what we can STILL do" though 

[Andrew Gorman]

North Korea still has a bunch of hovercraft.

[Weaver]

If they had to "hop" to the Gulf in 1991, it'd probably be doable. There's friendly ports/stops all along the north of the Med, then Cyprus to Suez, then around the Arabian peninsular and into the Gulf. The trick would be organising the right fuel and supplies to meet them, but that should be doable too. All quite the epic effort though.

What I'm tending towards is that the RN buys a split fleet of fewer Hunts, plus, say, four hovercraft and maybe a tender/heavy-lifter as a large-scale experiment. They send the hovercraft to the Gulf, not because it's the purely best option, but because it's the first opportunity to test them in a real war. The argument from the hovercraft unit is that although it's a pain getting them there, once in-theatre they can operate from a random beach (or their lifter/tender) rather than overcrowded port facilities. It's analogous to the argument for USMC Harriers operating from a FOL on the coast road, rather than overcrowded airbases.

Right    Rather as I thought. It would be an interesting example of a nation saying "Look what we can STILL do" though 

Also a great shop window for the product, right in front of the nations who can a) afford the running costs in their sleep and b) have a genuine need for the capability.

[jcf]

Not sure they'd need to worry about the Suez Canal, the could just zap across the desert if need be. 

Saudi Arabia's not as flat as people imagine. There's quite a few mountain ranges and even the desert has steep dunes. You'd have to very carefully survey a route to make sure a big hovercraft wouldn't get stuck. Also, how much sand can the engines eat? No point getting there with clapped-out engines, and sand filters would take time to design, test, and build.

The biggest issue with hovercraft is skirt life, they're limited to fewer hours than people
realize, even with the finger type in which the fingers can be replaced. Flogging in rough
water is a problem, which increases the rate of wear above of that the erosion caused by
friction with the surface of the water. The average life of the skirt sections of the SR.N4
Mk.II was 200 hours, improvements in materials increased the average life to 300 hours on
the Mk.III. Running across land for anything other than short distances, even flat sand, if
you can find it, or marshy ground dramatically shortens the life of the skirt. Trying to operate
in a desert environment would degrade the life to unnaceptable levels, probably to less than
100 hours on sand, maybe 50 to 75 hours if you're lucky, considerably less on the typically
rocky surface of supposedly smooth deserts.

[jcf]

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[PR19_Kit]

........ see my post #52................

[Weaver]

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Yikes: that 76mm has got a LOT of recoil for a lightweight structure to absorb. I'd have been more inclined to fit twin 40 or 35mm at each end and depend on rate-of-fire to compensate for the aiming difficulties.