Metal fuel tank materials?

[chris ballance]

I'm sure getting hit with a paper tank would ruin your day as well, but no scrap metal benefits.

this place is a gold mine...fiber tank 63 lbs...
Empty weight of drop tanks

 

[MIflyer]

Lockheed made steel drop tanks.

 

[MIflyer]

The Piper Skycycle fuselage reportedly was made by using a nonmetallic surplus F4U drop tank.

Wouldn't you love to have one of those?

 

[Snautzer01]

it would be a hit now i think,

 

[MiTasol]

You wonder what would have happened to a steel drop tank hitting the water at +200 knots. Also what are the chances some random trawler gets hit with one? Probably ruin a good fishing trip.

Probably much slower than that as they are very light and have a large surface area and they probably tumble because of the attachment hardware screwing the aerodynamics

 

[FLYBOYJ]

Lockheed made steel drop tanks.

Yep - and they made great hot rods after the war.

 

[FLYBOYJ]

 

[GrauGeist]

They actually created an entirely new class of racing

 

[MIflyer]

I recall that only a couple of miles from our house there was a big drop tank sitting in a field on a little cart. I've never been able to figure out what kind of airplane it went on, but it was a pretty big one, probably at least 300 gallons, and was not long and thin like those on F-105's and F-4's. Always wish I had been able to get hold of that thing.

 

[MIflyer]

I recall reading that when Ed Heinimen designed the A-4, they pointed out to him that it was too bad that such a small sleek airplane had to haul those big draggy WWII bombs. He replied, "You're still using those?" and sat down and designed the first low drag bombs. Airplane companies were worried about the drop tanks for their airplanes, since they were an essential element for jets, but not the bombs.

 

[Big Jake]

On the B-17, for example, the fuel tanks in the wing as well as the oil tanks were bladders made of rubber and were self-sealing. The same was for the B-29, F4U, P-51 and many more US aircraft. The auxiliary fuel tanks carried in the bomb bay of the B-17 and B-29 were aluminum. Wet wings were very rare as the sealing methods and materials available at the time were not adequate for the job. In addition, flexible structures made wet-wings even harder to seal. Case in point is the Vultee BT-13 which has a wet wing and is just about impossible to keep from leaking.

 

[FLYBOYJ]

On the B-17, for example, the fuel tanks in the wing as well as the oil tanks were bladders made of rubber and were self-sealing. The same was for the B-29, F4U, P-51 and many more US aircraft. The auxiliary fuel tanks carried in the bomb bay of the B-17 and B-29 were aluminum. Wet wings were very rare as the sealing methods and materials available at the time were not adequate for the job. In addition, flexible structures made wet-wings even harder to seal. Case in point is the Vultee BT-13 which has a wet wing and is just about impossible to keep from leaking.

I think you're mistaken about the B-17 oil tanks

 

[GrauGeist]

The only "rubber bladder" fuel tanks I'm aware of, where the additional "Tokyo Tanks" installed on B-17s and B-24s to increase their range.
Otherwise, their standard fuel tanks were metal, as were the tanks on the P-51 and other US fighters.

 

[MiTasol]

Some US manufacturers used rubber tanks inside a metal shell. The P-40 fuselage tank is an example and I strongly suspect the B-17 oil tanks were the same - unfortunately I do not have time to check. In both cases this makes sense as inserting/dragging a bladder/covered metal tank in/out through the cockpit is almost certain to result in damage to the bladder/covered metal tank non metallic skin. In the case of the B-17 inboard oil tank you are again working in a difficult location with plenty of sharp edges. The other thing to remember is that today a bladder tank is made of thin material that folds up for removal or installation. The WW2 self sealing tanks were very thick and very rigid.

 

[FLYBOYJ]

Some US manufacturers used rubber tanks inside a metal shell. The P-40 fuselage tank is an example and I strongly suspect the B-17 oil tanks were the same - unfortunately I do not have time to check. In both cases this makes sense as inserting/dragging a bladder/covered metal tank in/out through the cockpit is almost certain to result in damage to the bladder/covered metal tank non metallic skin. In the case of the B-17 inboard oil tank you are again working in a difficult location with plenty of sharp edges. The other thing to remember is that today a bladder tank is made of thin material that folds up for removal or installation. The WW2 self sealing tanks were very thick and very rigid.

View attachment 679007

That photo looks like the oil tank in the schematic I posted! I stand to be corrected!

 

[elbmc1969]

thanks, should have googled more for photos, and I would have found pictures like this of a B-17 and Blackburn Skua tanks, but I was searching for text.

The most charming aspect of the Skua was that it came with a large bag of corks of various sizes (conveniently color-coded!), so that the Wireless Telegraphist could plug holes in the fuel tank!

 

[MiTasol]

I have found my (incomplete) photocopy of RAF AP 4117A vol I & vol XI Aircraft Rigid Tanks General and Technical info

Give me a few days to scan and post

Despite the title it covers a lot of flexible tanks.

 

[ThomasP]

 

[chris ballance]

The most charming aspect of the Skua was that it came with a large bag of corks of various sizes (conveniently color-coded!), so that the Wireless Telegraphist could plug holes in the fuel tank!

Charming indeed. The color coding is the best part. I can totally see that conversation play out.

 

[special ed]

Photos of self sealing fuel tanks from Douglas B-26 can be seen Thread AvPix Unlimited, page 13, posts 251 & 260.