PDA

View Full Version : 30mm cannon vs spit wing whole film



Freiwillige
09-19-2009, 04:26 AM
http://www.youtube.com/watch?v...M3fk&feature=channel (http://www.youtube.com/watch?v=ZoLLDi-M3fk&feature=channel)

Ive seen the footage but never the close up.
The damage is ugly!

jmazzo
09-19-2009, 04:45 AM
cool!

horseback
09-19-2009, 10:13 AM
What impressed me most is that they were able to hit anything with that cannon, even with a static set up; when it comes to the 30mm guns I can't hit the broad side of a barn, even when I'm inside it.


Also, did you notice how the aluminum sheets on that wing just peeled away? At 400kph or so, that wing would literally tear itself apart in a split second...

cheers

horseback

Kettenhunde
09-19-2009, 10:23 AM
What impressed me most is that they were able to hit anything with that cannon,

It was a 400 meter point blank zero in a centerline installation.

That means it was point and shoot out to 400 meters at an aircraft size target.

http://img176.imageshack.us/img176/8766/ta152schusswaffenanlage.jpg (http://img176.imageshack.us/i/ta152schusswaffenanlage.jpg/)

The large max ord you see on most aircraft weapons is due to installation location in relations to the sight line. It is not the max ord of the weapon.

The installation limits all of these weapons significantly.

stalkervision
09-19-2009, 11:44 AM
even the twenty mm explosive shell has quite an effect. A few of those into a spitfire's wing is all you need. http://forums.ubi.com/images/smilies/winky.gif

JtD
09-19-2009, 11:50 AM
It should be noted that this hit was in the thickest part of the wing, were the projectile is least effective. You could expect even more damage if you move towards the tip of the wing.

stalkervision
09-19-2009, 12:15 PM
i wonder what a 30 mm hit would do to the fuselage? http://forums.ubi.com/images/smilies/winky.gif

JtD
09-19-2009, 01:41 PM
Less.

Flight_boy1990
09-19-2009, 01:46 PM
Originally posted by stalkervision:
i wonder what a 30 mm hit would do to the fuselage? http://forums.ubi.com/images/smilies/winky.gif

http://www.hgsc.bcm.tmc.edu/images/Bang.jpg

M_Gunz
09-19-2009, 02:20 PM
Originally posted by JtD:
It should be noted that this hit was in the thickest part of the wing, were the projectile is least effective. You could expect even more damage if you move towards the tip of the wing.

Don't be so sure. Shockwaves in a cavity the right size for the size of the bomb reinforce each other in the Mach Stem effect
that is far greater than twice one set of waves. Ever seen the picture of where they hung one 108 in the rear fuselage of a
bomber? It made holes on either side nearly as large as the height of the fuselage there. Again, the waves reinforced.

Try Google on Mach Stem Lockerbie. Hypersonic shockwaves are more than volume of gas. Too close to one wall and no effect.

JtD
09-19-2009, 03:54 PM
I didn't google this (yet), but I was giving a general trend. And the general trend is - the larger the volume the smaller the effect of the explosion inside, isn't it. But that's just one part of it anyway, the other is that the wing structure gets weaker as it goes to the tip, so the same damage that does nothing to a wing spar at the root may break it a couple of meters outwards.

I do agree that gas dynamics can totally reverse the general trend on occasion. I'm not sure about a bomber, but there is a Spitfire picture around which disagrees with my "Less" thesis.

http://farm1.static.flickr.com/206/469646329_dee07050e0_o.jpg

Waldo.Pepper
09-19-2009, 04:56 PM
Originally posted by M_Gunz:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by JtD:
It should be noted that this hit was in the thickest part of the wing, were the projectile is least effective. You could expect even more damage if you move towards the tip of the wing.

Don't be so sure. Shockwaves in a cavity the right size for the size of the bomb reinforce each other in the Mach Stem effect
that is far greater than twice one set of waves. Ever seen the picture of where they hung one 108 in the rear fuselage of a
bomber? It made holes on either side nearly as large as the height of the fuselage there. Again, the waves reinforced.

Try Google on Mach Stem Lockerbie. Hypersonic shockwaves are more than volume of gas. Too close to one wall and no effect. </div></BLOCKQUOTE>

+1 M_Gunz is right here. More of the energy is deposited in the target plane.

Xiolablu3
09-20-2009, 07:09 AM
Originally posted by JtD:
I didn't google this (yet), but I was giving a general trend. And the general trend is - the larger the volume the smaller the effect of the explosion inside, isn't it. But that's just one part of it anyway, the other is that the wing structure gets weaker as it goes to the tip, so the same damage that does nothing to a wing spar at the root may break it a couple of meters outwards.

I do agree that gas dynamics can totally reverse the general trend on occasion. I'm not sure about a bomber, but there is a Spitfire picture around which disagrees with my "Less" thesis.

http://farm1.static.flickr.com/206/469646329_dee07050e0_o.jpg


Was that a real combat damage or a test? I dont see how the plane could have survived if it was in the air.

Maybe a ground strafe attack?

WTE_Galway
09-20-2009, 07:16 AM
If i recall correctly that photo is of a static ground test with a 20mm shell placed inside the fuselage and detonated.

The shells in question ...

http://i4.photobucket.com/albums/y101/clannagh/ammunition.jpg

Flight_boy1990
09-20-2009, 08:21 AM
Somewhere on YouTube there is a guncamera footage from 30 mm armed FW-190 (IIRC),the FW-190 attacked Spitfire from 6 o'clock maybe 200-300 meters,the Spitfire was dismantled instantly,just like in IL-2.

horseback
09-20-2009, 10:47 AM
These pictures really point out the importance of the metal skinning to the airframe's structural strength; once a section of aluminum sheet (and it was sheet, not plate; in the cases of the Zero and Ki-43 it was closer to foil thickness) starts tearing, the airstream could literally tear the aircraft apart.

Adds credibility to gun camera film showing big chunks of stuff flying off after a concentrated burst of almost any caliber. If the rounds are closely spaced, the sheeting tears and peels, superhurricane force winds can get inside the airframe, tearing and overstressing more of the airframe & adjacent panels, fuel and oil vapor makes an explosive mixture, in short Bad Things Happen.

You didn't need to always hit a vital component on a lightly built fighter; you just needed to tear off chunks of the wing or fuselage.

Here's hoping that the BoB DMs reflect this.

cheers

horseback

M_Gunz
09-20-2009, 10:50 AM
They hung a 108 MG shell in the back of one grounded fuselage to do just about that, Xio, but IIRC it was in a bomber
like a Blenheim or Wellington.

Manu-6S
09-20-2009, 11:14 AM
Originally posted by Flight_boy1990:
Somewhere on YouTube there is a guncamera footage from 30 mm armed FW-190 (IIRC),the FW-190 attacked Spitfire from 6 o'clock maybe 200-300 meters,the Spitfire was dismantled instantly,just like in IL-2.

Link, link, link!!!!

Flight_boy1990
09-20-2009, 12:58 PM
Originally posted by Manu-6S:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Flight_boy1990:
Somewhere on YouTube there is a guncamera footage from 30 mm armed FW-190 (IIRC),the FW-190 attacked Spitfire from 6 o'clock maybe 200-300 meters,the Spitfire was dismantled instantly,just like in IL-2.

Link, link, link!!!! </div></BLOCKQUOTE>

Look here (http://www.youtube.com/watch?v=AKh0kS0fJjQ) at 1:05.