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XyZspineZyX
07-30-2003, 05:16 PM
Are they coated w/ something?

Is there something in the fuel that plugs the leak?

I've no idea and am confidant some of you do.




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Message Edited on 07/30/0312:16PM by georgeo76

XyZspineZyX
07-30-2003, 05:16 PM
Are they coated w/ something?

Is there something in the fuel that plugs the leak?

I've no idea and am confidant some of you do.




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"Altitude, speed, maneuver, fire!"-The "formula of Terror" of Aleksandr Pokryshkin, Three times awarded the rank of Hero of the Soviet Union

Message Edited on 07/30/0312:16PM by georgeo76

XyZspineZyX
07-30-2003, 05:23 PM
Most of the tanks had a soft rubber lining in the wall . When a bullet went thru the rubber that was tightly packed would fill the space.

Some of them had a gel that would hardden somewhat when air and fuel got on it. But most had a packing in the wall of the tank..

XyZspineZyX
07-30-2003, 05:48 PM
Also some Aircraft use fuel to extinguish the fire as well /i/smilies/16x16_smiley-happy.gif and some the rubber would swell when in contact with fuel

XyZspineZyX
07-30-2003, 05:55 PM
Self-sealing fuel tanks were as important as armour. Early attempts involved covering the inside or outside of a metal tank with some soft material, which expanded in contact with fuel, to seal any bullet holes. But this was not very efficient, and it was soon discovered that the bullet entry holes were a comparatively minor problem. The exit holes made by the tumbling bullets were considerably larger. Worse, the shock of impact and the pressure wave inside the tank caused it to rupture. In the first American tests, the entry holes were small, but the entire rear of the tank was knocked out.The answer was a flexible fuel cell of self-sealing material, with as few seams as possible, and suspended in straps so that it could absorb shocks without rupture. Such a tank should not be in direct contact with the fuselage skin, because the moving tank could cause the skin to buckle, the torn metal skin could cut into the tank, sparks were often generated when the projectiles passed through the metal skin, and the skin might trigger explosive rounds.

Evidently, self-sealing fuel tank installations were costly both in weight and in volume compared with conventional fuel tanks. And of course there was also a limit to their usefulness. The US Navy designed its self-sealing tanks to resist .50 hits and found that they also offered some protection against 20 mm hits. But if an explosive round blasted a large hole in the wall of the tank there was no hope to seal it. For high-altitude aircraft the fuel tanks had to be pressurised, but that made sealing far more difficult. Hence self-sealing tanks were increasingly replaced by integral fuel tankage after the war, despite the higher vulnerability.



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XyZspineZyX
07-30-2003, 06:31 PM
-The selfsealing fueltanks-

Fueltanks are covered with Many layers of soft( and hard rubber.The soft rubber in between hard one expands and seals the hole.
Brittish pilot discovered that they needed 20mm hispanos to rupture He-111 fueltanks

Capt._Tenneal
05-27-2004, 12:10 PM
What planes have this feature in FB/AEP ? Just a general list will do. Are they modelled in the game and have you seen it work ? It seems like every plane that leaks fuel in a dogfight will continue to show that fuel vapor trail until it crashes or belly-lands.

Cragger
05-27-2004, 01:53 PM
Some planes have sealing tanks, or seperated tanks so that one bleeds dry the others don't. Examples of this are the LaGG, Yaks, Las, that I know of for sure.

Most of the American aircraft conversly are modeled without them and as just having one large tank so they will eventually bleed dry from a small leak, a good example of this is the P-47. I have yet to see a difference in 2.1 if a change was made.

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Korolov
05-27-2004, 02:09 PM
You guys know you've just opened up a 10 month old thread?

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Cragger
05-27-2004, 02:26 PM
Whats wrong with that? He searched and found a thread and then asked a question directly related to that thread instead of posting a new thread. This is actually the proper way of going about things instead of remaking threads.

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Capt._Tenneal
05-27-2004, 02:36 PM
Cragger's right. I was about to start a new thread, then remembered to use the SEARCH function at the last minute and saw this old thread. http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

The reason for my question was that I read that one of the innovations that the LW had early in the war (like back in '39 or '40 even) was self-sealing tanks. But I have yet to see a 109 or 190 stop leaking fuel in the game.

F19_Ob
05-27-2004, 04:41 PM
Selfsealing tanks (some) consists of two neoprene bladders (one inside another).
Raw rubber were then filled between these. When the tank was hit and punctured the fuel came in contact with the raw rubber, causing it (the rubber) to swell and seal the holes.
A 20mm shell was to big to seal though, and some german 20-30mm shells exploded at contact with liquid only.

there U go....one from me too.
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BerkshireHunt
05-27-2004, 04:56 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Capt._Tenneal:
The reason for my question was that I read that one of the innovations that the LW had early in the war (like back in '39 or '40 even) was self-sealing tanks. But I have yet to see a 109 or 190 stop leaking fuel in the game.<HR></BLOCKQUOTE>

The earliest German attempts at protecting fuel tanks involved no more than leather coverings tailored to fit- the hope was that the leather would absorb some impact energy and help prevent fuel leaks. Later they introduced unvulcanised rubber coverings in addition to the leather. Unvulcanised rubber has the peculiar quality of swelling when in contact with hydrocarbons (and CO2). As fuel escapes through a hole the rubber swells and puckers so sealing off the rupture. Takes a while though. A similar substance was in use in British aircraft called, I believe, Linatex.

Re the FW190:
At the risk of upsetting the fanboys- but in ruthless pursuance of the truth(!)- I offer the following paragraph (from 'Under the Red Star- Luftwaffe Aircraft in Soviet Service' by Carl Fredrik Geust):

"Another FW190 made a forced landing in winter 1943 at the North Western Front covered by the 6th Air Army commanded by Maj. Gen Fyodor P. Polynin (made a Hero of the Soviet Union on 14th November 1938 as a volunteer pilot in China). The Inspector of the VVS Headquarters, Col. N G Seleznev arrived from Moscow to test it. After two days of meticulous inspection on the ground he made the first flight- and found the FW190 heavy in aerobatics. In his opinion the new Soviet fighters were more manoeuvrable. Seleznev recommended to attack the FW190 from above or from underneath where it was vulnerable. Among the other deficiencies noted by him were POOR FORWARD VISION, and the UNSHIELDED FUEL TANK which could be easily set on fire. On explicit orders the aircraft was later ferried to Moscow for further investigation by Seleznev."

So it seems the 190A4- A6 did not have much in the way of armour protection for its fuel tanks, though they were undoubtedly of the self- sealing type.

Athosd
05-27-2004, 09:33 PM
I've seen what certainly appeared to be a fuel leak sealing off in IL2 (2.01).

Whilst flying an escort mission in a 109G2 I was damaged by flak and noted the "fuel leak" message. External view confirmed the bad news and I decided to head for home keeping an eye on the fuel guage. When the gauge didn't move significantly in a few minutes I again checked the external view - no vapour trail.
I rejoined the mission and completed it without running short of fuel (~30min of flight after the leak message appeared).

Cheers

Athos