Geodetic design

Yes. All the Geodetic structure aircraft were fabric covered, they couldn’t be anything else (see my notes, and others, above). So the Wellesley, Wellington, Warwick and Windsor were all fabric covered.

The Vickers range of aircraft is not something I have really looked at in detail and when I saw the Brooklands Wellington it was just a framework so it didn’t occur to me but thanks for telling me that. I often wondered why the skin on the Wellington photograph on divetheworld.com had lost it’s skin so completely so that answers it. I did dive the wreck of a Wellington but the visibility was so bad I couldn’t see the whole picture.

Ali

Does that mean that the Warwick was fabric covered too?

Yes. All the Geodetic structure aircraft were fabric covered, they couldn’t be anything else (see my notes, and others, above). So the Wellesley, Wellington, Warwick and Windsor were all fabric covered.

Back in the 1960/70s, when I worked at BAC/BAe Weybridge, someone showed me a picture (or maybe the machine itself) that was used to ‘roll’ the frames for geodetic construction on the Wimpey.

It was much like an ordinary rolling machine, which twists the metal as it comes out. So it wasn’t as difficult to fabricate the fuselage as you might think. The people at Weybridge were very good at making specialised machinery to manufacture (or test) aircraft parts.

As far as I know, one of the really good things about geodetic construction was the damage limitation achieved in a wartime situation. Ribs and stringers so damaged could ‘fail’ the whole structure, whereas one or two geodetic joints being shot out would not. I understand many Wimpeys came back with lots of holes!

Bri

I had heard of this and just looked it up. I always wondered how he managed to hold on

On the night of 7th July, 1941, Sergeant Ward was second pilot of a Wellington returning from an attack on Munster. When flying over the Zuider Zee at 13,000 feet, the aircraft was attacked from beneath by a Messerschmitt 110, which secured hits with cannon shell and incendiary bullets. The rear gunner was wounded in the foot but delivered a burst of fire which sent the enemy fighter down, apparently out of control.

Fire then broke out near the starboard engine, and, fed by petrol from a split pipe, quickly gained an alarming hold and threatened to spread to the entire wing. The crew forced a hole in the fuselage and made strenuous efforts to reduce the fire with extinguishers and even the coffee in their vacuum flasks, but without success. They were then warned to be ready to abandon the aircraft.

As a last resort, Sergeant Ward volunteered to make an attempt to smother the fire with an engine cover which happened to be in use as a cushion. At first he proposed to discard his parachute, to reduce wind resistance, but was finally persuaded to take it. A rope from the dinghy was tied to him, though this was of little help and might have become a danger had he been blown off the aircraft. With the help of the navigator, he then climbed through the narrow astro-hatch and put on his parachute. The bomber was flying at a reduced speed, but the wind pressure must have been sufficient to render the operation one of extreme difficulty. Breaking the fabric to make hand and foot holds where necessary, and also taking advantage of existing holes in the fabric, Sergeant Ward succeeded in descending three feet to the wing and proceeding another three feet to a position behind the engine, despite the slipstream from the airscrew, which nearly blew him off the wing. Lying in this precarious position, he smothered the fire in the wing fabric and tried to push the cover into the hole in the wing and on to the leaking pipe from which the fire came. As soon as he moved his hand, however, the terrific wind blew the cover out and when he tried again it was lost. Tired as he was, he was able with the navigator’s assistance to make successfully the perilous journey back onto the aircraft.

There was now no danger of the fire spreading from the petrol pipe, as there was no fabric left nearby, and in due course it burnt itself out. When the aircraft was nearly home some petrol which had collected in the wing blazed up furiously but died down quite suddenly. A safe landing was then made despite the damage sustained by the aircraft. The flight home had been made possible by the gallant action of Sergeant Ward in extinguishing the fire on the wing in circumstances of the greatest difficulty and at the risk of his life.

Ali

The only metal skinning is on the nacelles, and is visible in the photos. The rest was fabric, which has, of course, decayed and vanished.

As a genuine geodesic type design I’ve only heard of one non-Vickers design which was a French aircraft exhibited in the 1930s without fabric at one of the Salons they had then. The jury was out about the full story.

Does that mean that the Warwick was fabric covered too?

Ali

Geodetics

Back in the 1960/70s, when I worked at BAC/BAe Weybridge, someone showed me a picture (or maybe the machine itself) that was used to ‘roll’ the frames for geodetic construction on the Wimpey.

It was much like an ordinary rolling machine, which twists the metal as it comes out. So it wasn’t as difficult to fabricate the fuselage as you might think. The people at Weybridge were very good at making specialised machinery to manufacture (or test) aircraft parts.

As far as I know, one of the really good things about geodetic construction was the damage limitation achieved in a wartime situation. Ribs and stringers so damaged could ‘fail’ the whole structure, whereas one or two geodetic joints being shot out would not. I understand many Wimpeys came back with lots of holes!

Bri

.

Wimpy with a wart!

….more commonly known as an astrodome?

Great pictures, but is that a top turret? In which case, is it in fact a Warwick?

Good question. However a quick check shows the Warwick’s turret was fitted much further aft, and the engine nacelles are quite different.

Wimpy with a wart!

There is a good photo of one underwater. The intersting part is that ALL the skin seems to have gone. I have been on a lot of sea wrecks and you will always find at least some of the skin.

http://www.divetheworld.com/Diving/warbirds/Wellington/index.htm

Ali

Great pictures, but is that a top turret? In which case, is it in fact a Warwick?

Yes, I think Charlie Andrews got that right.
I can confirm that the Wellington’s fuselage was a bit of an oddity. Certainly the aircraft typically corkscrewed through the air with the nose tracking a circle around the horizon. Pilots learned to live with this as distinct from fight it. ( Incidentally the Brit did the same I am told- but that is off thread !)

According to “Jane’s Fighting Aircraft of World War II” the Wellington length is 64 ft 7 in.

It has been reported that the Viking, Valetta and Varsity all retained geodetic structures under the metal skin, but I’d love some confirmation or denial of that.

According to Andrews in the Putnam Book the first 19 Vikings were geodetic structured “rag wings”. Unless I misunderstood it would appear that subsequent Vikings retained geodetic centre section structure (i.e. inboard of the engines ) under the skin.
I don’t know about the Varsity.[/QUOTE]

I remember seing a photograph in an flypast article about a Vikers Viking of the first production batch that had crashed somewhere in the UK mountains. The wreckage showed the inner wingstructure to be geodetic.

Cees

When the Wellington was tested as a glider tug for the Horsa it was found that the fuselage stretched (surprise) which showed up as a fore / aft movement of the control column with the aircraft straight and level.

And nobody ever knows the exact lenght of the Wellington’s fuselage. :p

Cees

When the Wellington was tested as a glider tug for the Horsa it was found that the fuselage stretched (surprise) which showed up as a fore / aft movement of the control column with the aircraft straight and level.

Apart from the Barnes Wallis designs of the Vickers Wellesley, Wellington and Warwick, .

Dave, That statment is a commonly made error.. 🙂 The Chief Designer at Vickers Aircraft was Rex Pierson and He and His team were responsable for the design of the 3 aircraft using the Barnes Wallis designed Geodetic structure.

Rex Pierson was, of course, Barnes Wallis boss !..

Interesting thread.. Will check on the Varsity structure this week..

Cheers
GASYD

Oh Ben! one digit out; you are a hard taskmaster!

Trying to redeem myself from Gift Aid embarassment! 😀

It has been reported that the Viking, Valetta and Varsity all retained geodetic structures under the metal skin, but I’d love some confirmation or denial of that.[/QUOTE]
According to Andrews in the Putnam Book the first 19 Vikings were geodetic structured “rag wings”. Unless I misunderstood it would appear that subsequent Vikings retained geodetic centre section structure (i.e. inboard of the engines ) under the skin.
I don’t know about the Varsity.

Thanks everyone, some interesting discussion here.

Apart from the Barnes Wallis designs of the Vickers Wellesley, Wellington and Warwick, have any other aircraft had geodetic construction? It seemed to prove to be a winner for strength but I guess it must have been more difficult to manufacture aircraft with this structure. Were there any other downsides? I mean it didn’t seem to catch on despite the success of the Wellington.

The original Vickers G4/31 Type 236 had a geodetic fuselage, very similar to the Wellesley (Designed as a private venture to the same spec). The 236 was predered, but the Wellesly was so superior that the oreder was changed to those.

It has been reported that the Viking, Valetta and Varsity all retained geodetic structures under the metal skin, but I’d love some confirmation or denial of that.

The metal geodetic structure carried the structural loads in the same way as other open fabric covered (wood or metal)airframes did during that period, the fabric being the aerodynamic fairing. The structure also flexed alot which fabric was happy to allow.
It would have defeated the object to cover it with metal as that would have added weight,complexity and cost when new, and when in service battle damage repairs were easier to tackle.
Gradually since the 1930’s metal and composite skins of wings and fuselage have became the main load bearing member of the structure.

I think they did not cover the wings and fuselage with metal, because the structure is rather flexible, and moves! That could make metal skinning a problem.

If you are making a metal skin, it’s normally only worthwhile for weight reasons to make it stressed skin, so that the skinning takes some of the loads – normally (again) a semi-monocoque construction. (An exception was the Beardmore Inflexible, IIRC, a metal clad non-stressed skin construction.) The Geodetic construction was designed to take all the loads through the metal parts and the fabric skinning took none of the load. If you were going to then cover it with metal, you didn’t need as strong a geodetic construction underneath, and it would negate the elasticity and load-transmission of the geodetic members as well.

An odd but effective domestic comparison example would be the string bag versus the plastic bag. A plastic bag’s a good means of carrying something, until it starts a rip, where it will tear in a second. A string bag (for those that can remember them!) will deform and surround any odd shaped load, and won’t rip. Putting a string bag inside a plastic bag is pointless; yes it’s strong, but it negates the benefits of each system and adds nothing but weight.

A string bag for those who’ve never seen one:

Springbok’s right in that the structure of the Wimpy was flexible, and the fabric allowed for that, but that’s not the reason for the construction method. The wing fabric completed the airfoil, and flew the aircraft; you could say that the fuselage fabric was there to make sure the navigator wasn’t bothered by the breeze and that his pens wouldn’t fall out of the bottom!

The Wimpy and family were extremely flexible; but in a certain environment, very effective – the Wellesleys held several world records for distance flying in the ’30s. At the upper end of the size scale however, the Windsor’s wings flapped slowly in flight, which was disconcerting to say the least, and caused all sorts of problems for the cables tubes and controls inside those wings.

There is a good photo of one underwater. The interesting part is that ALL the skin seems to have gone. I have been on a lot of sea wrecks and you will always find at least some of the skin.

The only metal skinning is on the nacelles, and is visible in the photos. The rest was fabric, which has, of course, decayed and vanished.

As a genuine geodesic type design I’ve only heard of one non-Vickers design which was a French aircraft exhibited in the 1930s without fabric at one of the Salons they had then. The jury was out about the full story.