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Grendel-B
01-04-2006, 02:11 PM
Ian McLachlan, bomber crew, 24th war sortie
452nd Bomb Group, 24.12.1944, , plane B-17G 42-31358.

"Two FW 190s made a pass through our formation. They hit out ship with a 20 mm shell.
Our radio operator Phil was badly wounded by the explosion before he could sound the alarm. Phil had shrapnel in both arms, in his legs at the knees. He also had pieces of aluminium above his eyes and the radio room as like a sieve with two or three hundred small holes.
The oxygen system was damaged.
Slightly Dangerous was in a bad shape. The 20mm shell exploded in the left inner wing panel behind No.2 engine. The hole was large enough for two men to stand in. The trailing edge of the wing and the flaps were in tatters.
Control cables and electrical cables were sheared. The explosion missed a main fuel tank by six inches.
The left wing vibrated above 145 mph, so we could not keep up with the formation.
...
(rtb)
We made a straight-in approach for a hot landing without flaps.
(approach) Suddenly another plane was overhead and dropped down in front of us. Mac gunned all four engines to full boots and No.3 caught fire as we staggered across the air base.
(overshot the runway) Mac was evidently trying to crashland in a large, sloping field. The mail wheels tripped into treetops and pitched the bomber's nose violently downwards."

In the end the plane crashlanded heavily, with six of the crew perishing.

--

And all this from a single 20 mm strike at the wing.
Source: Flypast February 2006 issue, article "Always Maximum", page 32->

g.

Grendel-B
01-04-2006, 02:11 PM
Ian McLachlan, bomber crew, 24th war sortie
452nd Bomb Group, 24.12.1944, , plane B-17G 42-31358.

"Two FW 190s made a pass through our formation. They hit out ship with a 20 mm shell.
Our radio operator Phil was badly wounded by the explosion before he could sound the alarm. Phil had shrapnel in both arms, in his legs at the knees. He also had pieces of aluminium above his eyes and the radio room as like a sieve with two or three hundred small holes.
The oxygen system was damaged.
Slightly Dangerous was in a bad shape. The 20mm shell exploded in the left inner wing panel behind No.2 engine. The hole was large enough for two men to stand in. The trailing edge of the wing and the flaps were in tatters.
Control cables and electrical cables were sheared. The explosion missed a main fuel tank by six inches.
The left wing vibrated above 145 mph, so we could not keep up with the formation.
...
(rtb)
We made a straight-in approach for a hot landing without flaps.
(approach) Suddenly another plane was overhead and dropped down in front of us. Mac gunned all four engines to full boots and No.3 caught fire as we staggered across the air base.
(overshot the runway) Mac was evidently trying to crashland in a large, sloping field. The mail wheels tripped into treetops and pitched the bomber's nose violently downwards."

In the end the plane crashlanded heavily, with six of the crew perishing.

--

And all this from a single 20 mm strike at the wing.
Source: Flypast February 2006 issue, article "Always Maximum", page 32->

g.

JuHa-
01-04-2006, 02:14 PM
Did it hit something volatile at that location?

ImpStarDuece
01-04-2006, 02:17 PM
How did the know it was a 20mm shell? Given that bomber destroyer FW 190s were operationally fitted with 30mm cannon, it could concievably of been as Mk 103 shell. Its probably a little hard to tell when a FW 190 pulls out from a firing run and flashes by your window at 150 mph + relative.

HayateAce
01-04-2006, 02:19 PM
http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

Terrific. Let me guess, you wan't to even further increase the already Klown-Like power of the 151 ammo?

Oh, and since every pro-allied pilot account is dismissed with the bat of a blue eyelash, let's toss this one out and say it was more likely a 30mm, one o'them stovepipe gerat thingies or the most likely of all, an 88mm from the ground.

Good day.

Grendel-B
01-04-2006, 02:23 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by HayateAce:
http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

Terrific. Let me guess, you wan't to even further increase the already Klown-Like power of the 151 ammo?
</div></BLOCKQUOTE>

Ahhhh. I knew there would be something merry stuff when I saw Hayatetarget replies. http://forums.ubi.com/groupee_common/emoticons/icon_smile.gif

Instant flameout. Bailout! Bailout!

Btw, did you see any comment on the historical account quote referring to IL2 game or any flight simulation?

A born troll, this chap ;-)

Brain32
01-04-2006, 02:30 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> Terrific. Let me guess, you wan't to even further increase the already Klown-Like power of the 151 ammo? </div></BLOCKQUOTE>

Leadspitter please come back, atleast you were funny...

Grendel-B
01-04-2006, 02:33 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by ImpStarDuece:
How did the know it was a 20mm shell?
...
Its probably a little hard to tell when a FW 190 pulls out from a firing run and flashes by your window at 150 mph + relative. </div></BLOCKQUOTE>

From damage assessment after landing the damaged bird. Standard procedure of examining the damage and examining the cause of it. The author specified the 20mm hit very clearly in his text in the article, on page 33 of the magazine.

Minengeschoss was very high powered HE shell and its power to damage is sometimes even surprisingly high.

berg417448
01-04-2006, 02:35 PM
More than likely it was a 30mm unless some eqipment in the plane exploded when hit. You have to take these things with a grain of salt sometimes. I once read an account of an Me-262 strafing ground troops and the troops on the ground kept referring to the 20mm cannons the 262 was firing. They simply didn't know that it was really 30mm fire.

hobnail
01-04-2006, 02:41 PM
Face it. It would be extremely difficult for a crewman to identify the type of round that did the damage. This is made even more difficult because by December 1944 it would be likely that the 190 that attacked had both 20mm and 30mm Mk108 onboard.

Second. "...before he could sound the alarm". Does this indicate that no one had visual on the attacking fighters beforehand? Even harder to identify the round used solely by the damage it caused.

Third. It's anyone's guess whether this was a regular 20mm, a 30mm or a freak shot with a 13mm MG. Any number of things could've happened, an oxygen bottle could've been hit, it was more than one round that hit...on and on. Further if it was an MG shell then why so much shrapnel? If it was a HE round, why so much explosive damage? and so on and so on...

Another case of Hystorical accuracy...

Grendel-B
01-04-2006, 02:45 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Hobnail:
Face it. It would be extremely difficult for a crewman to identify the type of round that did the damage.
</div></BLOCKQUOTE>

A crewman would not do a damage assessment report after a combat sortie. Qualified mechanics and other staff, who have been trained for this, do. A crewman is happy to land home and then can read the damage assessment report or discusses what happened with the mechanics/assessment staff.

Shouldn't that be completely clear to anybody?

Mr. McLachlan wouldn't know that "the explosion missed a main fuel tank by six inches" in air either, that is definitely something they notified when studying the wreck afterwards.


Added the end of the story to the original post. No matter what shell it was, though I do rather think the crew and researchers who were there know it better than we naysayers in internet, one shell was in the end enough to destroy the bomber, causing six of the crew to perish.

Brain32
01-04-2006, 02:45 PM
Why is this so hard to believe? If the story was about B-17 which recieved 10000 20mm shots, did it's mission sucessfully and landed safely, this discussion would be moved to ORR http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif
Strange things can happen, this is jsut a story no different than those about birds that recieved quite a punch and returned safely.
I'm sure if it was about FW or Me that went down from one .50 bullet everybody would accept it as undenyable truth - this is my friends also known as hypocrisy...

hobnail
01-04-2006, 03:15 PM
Yeh Brain! lets tar everyone with that same brush! yeehaw. Anyone dealing with absolutes in the study of history, especially military, has rocks (of whatever calibre) in their heads.

I don't see one mention of DA in that quote still, what I see is an eye-witness account of a 19 year old half-terrified farmboy (or 28 yo bank clerk whatever...) which is fraught with the usual reservations.

If they could tell it was 20mm, they still don't say "20mm HE" or "20mm HEI" etc...

I've got some HQ guncam of 20mm attacks on Libs and Forts and we could argue the whole other side to the argument. My point is that when you start taking potshots at an aluminium tube 15km up, anything can and will happen, why bother trying to divine some sense of predictable order...

Hristo_
01-04-2006, 03:39 PM
Maybe it was a captured ShVAK ? http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Kocur_
01-04-2006, 03:40 PM
Quantity of fragments doesnt really depend on thickness of shell walls, as there is no way, that shell walls would get stratified. Thickness of walls determines average weight of fragments. MG shell fragments would be small, thus light and fast, thus would do damage at short range from point of impact, but lose energy quickly flying further. Pretty much like in case of offensive hand grenades. Tony Williams mentiones in his book trials, where MG shell fragments did some damage to B-24 fuselage longerons, i.e. at short distance those fragments had enough energy to do some damage to aluminium parts.

I guess the only way to determine what caliber hit that B-17 and did that damage is (and was) comparing the size of the hole in that specific part of wing to previously known cases of hits of both calibers.

Abbuzze
01-04-2006, 03:51 PM
At the end, even if the story sounds dramatic, it is possible that this was just a good/lucky 20mm hit,
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">The 20mm shell exploded in the left inner wing panel behind No.2 engine. The hole was large enough for two men to stand in. The trailing edge of the wing and the flaps were in tatters. </div></BLOCKQUOTE>
If two man could stand in the hole, it´s around 50-60cm diameter in size, and it seems that the shell exploded inside the wing, where a HE had the best performance. Cutting cable is just luck, and flaps maybe destroyed through the gas pressure.
Nothing impossible, but of course bad luck for the Crew and the plane...

Brain32
01-04-2006, 04:00 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> At the end, even if the story sounds dramatic, it is possible that this was just a good/lucky 20mm hit,

quote:
The 20mm shell exploded in the left inner wing panel behind No.2 engine. The hole was large enough for two men to stand in. The trailing edge of the wing and the flaps were in tatters.

If two man could stand in the hole, it´s around 50-60cm diameter in size, and it seems that the shell exploded inside the wing, where a HE had the best performance. Cutting cable is just luck, and flaps maybe destroyed through the gas pressure.
Nothing impossible, but of course bad luck for the Crew and the plane...
</div></BLOCKQUOTE>

Exactly, sh** happens, this is just an anegdote...

Gibbage1
01-04-2006, 04:06 PM
Its possible to take down almost any aircraft with a single shot of almost any gun. Its called the "golden BB". The 1 in a million shot. It could of been a very well placed 20MM hit. But for that 1 bomber that went down with 1 hit, hundreds more came home with a lot more damage.

IL2, you can take down a B-17 with a single 20MM hit, if you hit the right spot. The cockpit or the outside of the wing are extreamly vulnerable in the game.

Waldo.Pepper
01-04-2006, 04:25 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Qualified mechanics and other staff, who have been trained for this, do </div></BLOCKQUOTE>

Sir

These same qualified staff routinely identified He-100's in combat and other things we now know to be false. Surely you realize that?

Read the caption on the following image! From 1945 no less!

http://img.photobucket.com/albums/v516/WaldoPepper/old%20messer/Jaguar.jpg


We will never know what the round was today.

Sergio_101
01-04-2006, 07:00 PM
42-31332/31431 Boeing B-17G-15-BO Fortress

31358 (452nd BG, 729th BS) lost May 29, 1944. MACR 5229

My guess is, with that kind of damage it was a 88mm hit.
Sounds like a lot of damage for a 20mm.

Sergio

Kocur_
01-04-2006, 10:22 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Waldo.Pepper:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Qualified mechanics and other staff, who have been trained for this, do </div></BLOCKQUOTE>

Sir

These same qualified staff routinely identified He-100's in combat and other things we now know to be false. Surely you realize that?

Read the caption on the following image! From 1945 no less!

http://img.photobucket.com/albums/v516/WaldoPepper/old%20messer/Jaguar.jpg


We will never know what the round was today. </div></BLOCKQUOTE>

There is a difference between SEEING and TOUCHING damage of a plane standing in base and guessing what planes the other side has. First is mechanical matter, the latter intelligence.
Or jounalistic, like in that case http://forums.ubi.com/images/smilies/16x16_smiley-very-happy.gif Btw. plane on the pic is Bf-162V2, rival of Ju-85/88 in Schnellbomber competition. Later it was used by German propaganda similarly to He-100. And text below photo says about 1940 and BoB, and their only source was "Berliner Ilustrierte Zeitung"...

Gibbage1
01-04-2006, 11:11 PM
For ANYONE who things that

A. 1 20MM taking a B-17 down is normal
B. 1 20MM SHOULD or COULD take down a B-17

Please visit this web page.

http://www.daveswarbirds.com/b-17/

Hristo_
01-04-2006, 11:34 PM
A single 20mm round SHOULD take down a B-17 if it hit and subsequently detonated a bomb in its bay OR pass through pilot AND copilot.

Otherwise, unlikely.

Gibbage1
01-05-2006, 12:03 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Hristo_:
A single 20mm round SHOULD take down a B-17 if it hit and subsequently detonated a bomb in its bay OR pass through pilot AND copilot.

Otherwise, unlikely. </div></BLOCKQUOTE>

It would take an EXTREAMLY lucky hit to detonate a bomb. The bomb itself is 450lb of metal with a 50lb explosive charge. A 20MM shell could not penetrate the shell. It would need to hit the detonator itself and even that would not guarantee an explosion. If you read, one of the accounts on the web page I posted, the bomb bay was hit by an 88MM shell and that only knocked the bombs free and dropped through the doors. Did not detonate the bomb.

As for the pilot, there is still a co-pilot and dual controles. There is a photo of a B-17 hit in the cockpit by a 20MM that decapitated the pilot, and the co-pilot flew it home.

The only true 1 shot kill is the fuel tanks. If an HE's fuse went of when inside the fueltank in the wing, the result would bring down a B-17. In IL2 that is modeled. If you hit the wings just outside of the engines, the wing will light up, and all too easy.

Heck, A B-17 even survived a FW-190 ramming it nearly slicing off the tail!!! These birds were tough. It would take 1 in a billion shot to take one of them down with 1 hit.

The thing is, in war, you dont need to take them down. Just keep them from there targets. Doing enough damage to make them return is good enough.

AKA_TAGERT
01-05-2006, 12:08 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gibbage1:
For ANYONE who things that

A. 1 20MM taking a B-17 down is normal
B. 1 20MM SHOULD or COULD take down a B-17

Please visit this web page.

http://www.daveswarbirds.com/b-17/ </div></BLOCKQUOTE>Roger Gibb.. what these smacktards fail to realise is that the exceptions (non-norm) to the rule (norm) do not disprove the rule (norm), they are simply the exceptions (non-norm), i.e. the tails of the bell curve.. i.e. anything is possiable, just some things are more possiable than others.

Hristo_
01-05-2006, 12:43 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gibbage1:

It would take an EXTREAMLY lucky hit to detonate a bomb. The bomb itself is 450lb of metal with a 50lb explosive charge. A 20MM shell could not penetrate the shell. It would need to hit the detonator itself and even that would not guarantee an explosion. If you read, one of the accounts on the web page I posted, the bomb bay was hit by an 88MM shell and that only knocked the bombs free and dropped through the doors. Did not detonate the bomb.
</div></BLOCKQUOTE>

What a 88mm HE shell does to a tank is to penetrate the hull and cause ammo cookoff, among many other bad things. Analogy could be done to a B-17 bomb bay.

I believe many of us here advocate DM where hitting cannon ammo in plane wings would cause catastrophic damage. Same thing.


There are documented cases of LW planes destroying B-17s in a ball of explosion, sometimes even going down themselves.

One particular account was a pair Me 262s, where the first one hit a B-17. The B-17 exploded in a huge fireball, taking down the first 262, while the second one flew through the debris, getting moderate damage. I have the video file of the 262 pilot who survived the incident. No 88mm shells were involved.


450lbs metal vs 50lbs explosive...

You are not hitting mass, you are hitting volume. Even if slightly exaggerated, your numbers are still not too informative. Specific weight of metal is several times greater than explosive specific weight. Your numbers would present quite similar volume of both components, which I find hard to believe. A WW2 bomb was not a missile - just a simple explosive package in a metal shell with fins.

In reality, volume of explosive is far greater and thus easier to hit. A delay fuse (common for most German HE shells) will do exactly that - a 20mm shell will penetrate the metal skin and detonate inside (the bomb, in this case).

German 20mm shells would go off only when they stopped rotating. This ensured two things: they would normally detonate inside the target and they would detonate before hitting the ground in case if they missed (no explosive toys falling on civilians).



<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
As for the pilot, there is still a co-pilot and dual controles. There is a photo of a B-17 hit in the cockpit by a 20MM that decapitated the pilot, and the co-pilot flew it home.
</div></BLOCKQUOTE>

Reread my post. It is exactly what you said. Both pilot and copilot had to be hit.


<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">
Heck, A B-17 even survived a FW-190 ramming it nearly slicing off the tail!!! These birds were tough. It would take 1 in a billion shot to take one of them down with 1 hit.
</div></BLOCKQUOTE>

Irrelevant. How many B-17s survived bomb bay detonation or pilot & copilot killed ?


In reality B-17s were rugged planes loaded with tons of explosives and thousands of gallons of fuel, flying into flak screens and enemy fighters. Bad things were on their way. Be sure.

Monson74
01-05-2006, 12:45 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by AKA_TAGERT:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Gibbage1:
For ANYONE who things that

A. 1 20MM taking a B-17 down is normal
B. 1 20MM SHOULD or COULD take down a B-17

Please visit this web page.

http://www.daveswarbirds.com/b-17/ </div></BLOCKQUOTE>Roger Gibb.. what these smacktards fail to realise is that the exceptions (non-norm) to the rule (norm) do not disprove the rule (norm), they are simply the exceptions (non-norm), i.e. the tails of the bell curve.. i.e. anything is possiable, just some things are more possiable than others. </div></BLOCKQUOTE>

The theory of falsification does disprove the rule as such, thereby degrading it to a norm which is an entirely different thing. One must be careful not to mistake plausibles for facts & non-plausibles for non-facts. A fact constitutes the quality of an observed phenomenon but the plausible is deducted from the quantity of a measured phenomenon. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif

Grendel-B
01-05-2006, 01:47 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Waldo.Pepper:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Qualified mechanics and other staff, who have been trained for this, do </div></BLOCKQUOTE>

These same qualified staff routinely identified He-100's in combat and other things we now know to be false. Surely you realize that?

We will never know what the round was today. </div></BLOCKQUOTE>

Mechanics and damage assessment crew did not fly in combat. They were groundcrew.

If they decided the hit was from 20mm shell, when studying the wreck on ground after the crashlanding, then it was much more likely a 20mm shell than anyone else can guess 60 years later, without seeing the wreck and not having been there.

Sergio_101
01-05-2006, 02:37 AM
It was standard operating procedure for the pilots
of B-17s and B-24s to let the whole crew get
some training at flying the plane.

While I have nothing easily accessable right now
I have somewhere around here a few reports
of B-17s returning with both pilots dead.
These planes were flown by other crew members.

Sergio

Sturm_Williger
01-05-2006, 03:33 AM
While some bombs may have been able to resist being hit by a 20mm cannon shell, all bombs are not created equal.

A cannon shell striking a bundle of incendiaries in the bomb bay is very likely to ruin the rest of the day for the bomber crew.

Brain32
01-05-2006, 03:47 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> These birds were tough. It would take 1 in a billion shot to take one of them down with 1 hit. </div></BLOCKQUOTE>
I believe no less was fired on them http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content"> The thing is, in war, you dont need to take them down. Just keep them from there targets. Doing enough damage to make them return is good enough. </div></BLOCKQUOTE>
As much as I understanded the article topic starter posted, that B-17 DID return but had a crash landing so it's nothing spectacular. It's just an interesting war story so I really don't understand why was such fuss and disbelief raised about it http://forums.ubi.com/images/smilies/16x16_smiley-wink.gif

Kurfurst__
01-05-2006, 05:39 AM
I am a little sceptical about the 20mm round myself.. just to much damage from a single 20mm round, unless something helped it out. Guess it was a 30mm one.

BTW, here's a nice photo of another MK 108 test I just found :
http://img137.imagevenue.com/loc248/th_25bb0_Spitfire_hit_30mm.jpg (http://img137.imagevenue.com/img.php?loc=loc248&image=25bb0_Spitfire_hit_30mm.jpg)

Kocur_
01-05-2006, 08:09 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">It would take an EXTREAMLY lucky hit to detonate a bomb. The bomb itself is 450lb of metal with a 50lb explosive charge. A 20MM shell could not penetrate the shell. </div></BLOCKQUOTE>

HE bombs are just thin walls and explosive. Load factor that is achieved in HE bombs, i.e., those that are supposed to do damage primarily by blast and not by fragments, is about 50%. That means that explosive is about half of entire HE bomb weight. Data of common US bombs:
AN-M64 total: 500 lb, explosive: 262 lb,
AN-M65 total: 1,000 lb, 530 lb.

Why metal is as much as 50% of bomb weight? Low density of explosive makes the difference. Although explosive is like 90% of volume, its only 50% weight.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">A 20MM shell could not penetrate the shell.It would need to hit the detonator itself and even that would not guarantee an explosion. </div></BLOCKQUOTE>

A 20mm HE/MG projectile would penetrate HE bomb shell easily, assuming it had delayed fuse. Modern exposives, including those WW2, are quite safe, i.e. passive - they wont explode exposed to fire - will just burn. Detonator in the fuse causes exposion of explosive load by exploding in it thus delivering enough energy, by temperature and pressure, to cause explosive to go off. 20/30/etc. mm HE/MG exploding inside of bomb would do just that. But it had almost no chance to happen IRL, at least in case of few hits in bomb bay area. First, HE/MG projectile would have to have delayed fuse, otherwise it would go off just after hitting plane's skin. Second: if it was a delayed fuse, it would have quite a delay to reach bomb before going off after passing the skin. Remember that fighter didnt fire at bombers from perpedicular position to long axis, but at low angle. So to cause explosion of bombs in the bomb bay, it would take either shooting from below through OPENED bomb bay doors, or shoot burst long enough, so that first hits from a long burst would make holes in skin, and later projectiles would hit bombs inside. Both are not likely really. OTOH I read pretty much accounts from Polish nigh bombers crews, who wintnessed bombers explosing by their bombs during bomb run, i.e. AAA hit them, while bomb bay doors were opened.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">German 20mm shells would go off only when they stopped rotating. This ensured two things: they would normally detonate inside the target and they would detonate before hitting the ground in case if they missed (no explosive toys falling on civilians). </div></BLOCKQUOTE>

Wrong. Device based on lower inertia after rotation speed dropped was self destroying device only. Device in the fuse to cause explosion was usual firing pin-primer device. In case of impact fuse, primer would cause detonator to go off, by flames from primer going to detonator immidietly. In case of delayed fuse, a burning material was placed between primer and detonator. It was ignited by primer, burned for a certain time, and flame from that delaying metarial would cause explosion of detonator, which (in both cases) made explosive in the shell go off.

AKA_TAGERT
01-05-2006, 09:03 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Monson74:
The theory of falsification does disprove the rule as such, thereby degrading it to a norm which is an entirely different thing. One must be careful not to mistake plausibles for facts & non-plausibles for non-facts. A fact constitutes the quality of an observed phenomenon but the plausible is deducted from the quantity of a measured phenomenon. http://forums.ubi.com/groupee_common/emoticons/icon_wink.gif </div></BLOCKQUOTE>A knife that cuts both ways.

FinnBird
01-05-2006, 11:34 AM
Well, anything can happen with bad luck.

The Finnish Air Force lost one Ju-88 to two 7.62mm hits. (It dipped in the Kutvele channel)

The other bullet just went through without harm, but the other one hit an oxygen bottle. The bottle flew to the rear and crippled the elevator control mechanism.

I find it hard to believe that a two foot hole in the wing should be very common with just a one 20mm shell - maybe it did hit something flammable?

StellarRat
01-05-2006, 11:57 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Kocur_:
Quantity of fragments doesnt really depend on thickness of shell walls, as there is no way, that shell walls would get stratified. Thickness of walls determines average weight of fragments. MG shell fragments would be small, thus light and fast, thus would do damage at short range from point of impact, but lose energy quickly flying further. Pretty much like in case of offensive hand grenades. Tony Williams mentiones in his book trials, where MG shell fragments did some damage to B-24 fuselage longerons, i.e. at short distance those fragments had enough energy to do some damage to aluminium parts.

I guess the only way to determine what caliber hit that B-17 and did that damage is (and was) comparing the size of the hole in that specific part of wing to previously known cases of hits of both calibers. </div></BLOCKQUOTE>You're wrong. The wall thickness, shape and quality of the metal in the casing make a huge difference.

Kocur_
01-05-2006, 12:56 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by StellarRat:
You're wrong. The wall thickness, shape and quality of the metal in the casing make a huge difference. </div></BLOCKQUOTE>

Indeed, all together do. As large-grain cast iron projectile of large thickness would produce more fragments than soft-steel one. Not to mention projectile made of peculiar materials, like lead glass (between WWs experiments in hand grenades). OTOH changing thickness of walls of projectile made of soft steel from say 3mm to 6mm, while keeping shape and material wouldnt double quantity of fragments, would it.

Hawgdog
01-05-2006, 01:24 PM
Can it kill a tiger tank?
Maybe next patch we could get the P.11 with four 20mm's.

FluffyDucks
01-05-2006, 05:43 PM
I was always told if you don't know exactly what you're talking about to keep your trap shut rather than prove you are talking bollox.

Its obvious that we have some real experts in this forum that have made some very authoratative "statements of fact" and also :

a. Have experience,qualifications, and technical knowledge(rl) of WWII armanents and their capabilities from a first hand perspective.

b. Have experience, qualifications, and technical knowledge of WWII aeronautical engineering and damage assessment(rl).

It must be great to have so many experts that know exactly what they are talking about and are able to talk so authoratively about weapons and their ability or not to damage WWII aircraft.
I just think this forum is very lucky to have so many qualified engineers able to spare their time and tell us what is what. I thought they would be all to busy dealing with rl modern air accidents and research etc.... http://forums.ubi.com/groupee_common/emoticons/icon_rolleyes.gif

Sergio_101
01-05-2006, 05:49 PM
Nice heavily altered photo Kurfurst__ .
Did you use "paint" for the copy and paste?

But at least we seem to agree it was
most likely something bigger than a 20mm.
A secondary explosion is also doubtful
as there is nothing in that area in a B-17
that could cause that without blowing the plane
out of the sky immediatly.

Sergio