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View Full Version : Ballistic Glass: how effective?



XyZspineZyX
12-09-2004, 06:32 AM
I've noticed that the forward panels on a lot of cockpits are extra thick. I understand that this is special glass made to protect the pilot, am I right? Just how effective is this stuff? Can it stop .50's?

HansKnappstick
12-09-2004, 06:52 AM
No, a .50 cal kills a tiger.


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Sorry I just couldn't help ...

GerritJ9
12-09-2004, 07:26 AM
I remember seeing a part of a B-17 cockpit windscreen at the Imperial War Museum in London. The glass had been hit by German guns of varying calibre including 20mm rounds. Although huge chunks had been taken out, the glass had not been penetrated. Obviously I could not measure the thickness, but it was quite thick. Penetration or not depends in part on how thick the glass is.

WOLFMondo
12-09-2004, 08:53 AM
The glass is pretty thick, I've got 2 pieces at home...fashioned into 2 4cmx4cmx2cm Spitfire models my mothers father made out of old Spitfire armoured glass from a wreck at his airfield during the war. Its pretty **** tough as there all one piece and have props and undercarrage that haven't got broken in 60 years.

ucanfly
12-09-2004, 09:25 AM
Yeager makes the comment that the armoured glass saved him when he got plastered from a head on shot (by a 190) that was shooting 20mm.

GAU-8
12-09-2004, 02:40 PM
i did not realise HOW THICK it can be. a friend bought me a book

"AT THE CONTROLS":smithsonian national air and spacemuseum book of cockpits\

in it it shows the cockpit of IL-2M3 variant cockpit. 49 millimeter thick! you can see its thickness by the angle of glass in the cockpit.

ill try to scan a pic if i can get scanner workin.. oh yeah highly recommendable book too!

Von_Zero
12-09-2004, 03:18 PM
if my memory server me right, i think that pierre Closterman says about a spit pilot, that returned with a hole in the windhield, right near his head. Also i've read that the windshield on the Hs-129 could withstand a direct hit from a 37mm cannon http://forums.ubi.com/images/smilies/16x16_smiley-surprised.gif

HellToupee
12-09-2004, 03:23 PM
theres a case where a .50 tore thru the bottom of a spitfires cogpit ripped off the guys headgear and got stuck in the armourd glass.

XyZspineZyX
12-09-2004, 07:33 PM
I recall an account of a Hellcat pilot doing a steep strafing run on a Japanese capital ship... His guns jammed partway down and when he leaned over to manipulate the gun controls to try to clear the jam, a round crashed through his windscreen, gunsight, and imbedded into his headrest.

Since this round didn't blow him out of the cockpit or shred his back, I would presume that it was something less than 40mm...

So at least on the F6F that stuff is not impervious.

I wonder if people have any more specific information? How thick does the stuff need to be to resist .50 for example? 20mm?

How dense is this stuff too... geez, is it like transparent steel or something? Perhaps heavier I suppose...?

slarsson
12-09-2004, 08:10 PM
I have a tank window.
This is made of multiple layers of ballistic glass, in total about 6 inches thick.
No idea what it would stop............

ColoradoBBQ
12-09-2004, 08:34 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by AgentBif:
I recall an account of a Hellcat pilot doing a steep strafing run on a Japanese capital ship... His guns jammed partway down and when he leaned over to manipulate the gun controls to try to clear the jam, a round crashed through his windscreen, gunsight, and imbedded into his headrest.

Since this round didn't blow him out of the cockpit or shred his back, I would presume that it was something less than 40mm...

So at least on the F6F that stuff is not impervious.

I wonder if people have any more specific information? How thick does the stuff need to be to resist .50 for example? 20mm?

How dense is this stuff too... geez, is it like transparent steel or something? Perhaps heavier I suppose...? <HR></BLOCKQUOTE>

Its plexiglass. Its actually half as dense of glass but has better protection against bullets because it flexes a bit and doesn't shatter like glass. It could also be polycarbonate but I don't think they had it back then.

WTE_Dukayn
12-09-2004, 08:46 PM
Also have to factor in that a bullet hitting directly onto a flat piece of glass will punch thru easier than if it hits at an angle.

PBNA-Boosher
12-10-2004, 04:41 AM
The .50 can go through ballistic glass easily. you just have to skip it underneath it and the plane'll light right up!

Nutz1944
12-10-2004, 05:04 AM
As a kid near an Air Force Base, I had a P-51 armored wondscreen I bought for $2.00. A friend and I shot the armored front panel point blank with a 12 guage shotgun. Penetrated maybe an eighth of an inch and crazed the glass. But no other damage. Wish I had that windscreen now.

XyZspineZyX
12-10-2004, 06:20 AM
With buckshot I take it? Slug wouldn't penetrate either though... not even AP slug if the panel resists .50.

Ankanor
12-10-2004, 08:45 AM
We have in the Bulgarian Aviation Museum a windshield from a Me109G2/6. it was cracked by a 20mm round. This thing is 70mm thick. you could easily see where did the projectile hit - in the lower left corner of the windshield. the slug must have penetrated about 2-3 cm into the shield and tore off some small pieces. Just like when you break an ice cube, you tear some material from the surface and crack the stuff below the penetration point. But the thing is, the cracked pieces held together. Impressive http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif

About the IL-2 armor glass, the sturmovik was the first russian aircrfat ever to receive one. It's made of Quartz plates glued to a plexiglass base.
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR> I recall an account of a Hellcat pilot doing a steep strafing run on a Japanese capital ship... His guns jammed partway down and when he leaned over to manipulate the gun controls to try to clear the jam, a round crashed through his windscreen, gunsight, and imbedded into his headrest.

Since this round didn't blow him out of the cockpit or shred his back, I would presume that it was something less than 40mm... <HR></BLOCKQUOTE>

I bet it was a 25 mm. The usual light AA weapon found on IJN ships.

That pilots must have been really lucky. I would never even think of leaning over to fix something when I'm diving on a ground target http://forums.ubi.com/groupee_common/emoticons/icon_eek.gif

RJNewly
12-10-2004, 11:21 AM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by HellToupee:
theres a case where a .50 tore thru the bottom of a spitfires cogpit ripped off the guys headgear and got stuck in the armourd glass. <HR></BLOCKQUOTE>

Friendly fire?

Platypus_1.JaVA
12-10-2004, 11:53 AM
The thickness of Armoured glass was not the only protection. Alot depends on the ballistics of the projectile itself. Diameter, weight, muzzle velocity, distance, bullet speed, aircraft speed and probably some other factors are also involved.

Platypus_1.JaVA
12-10-2004, 11:55 AM
Anyhow, armoured glass saved lives and that is the most important part!

XyZspineZyX
12-12-2004, 03:43 AM
Aye, but it would be nice to know what thickness can resist what caliber and how dense the stuff is compared to actual armor.

pendragon1984
12-12-2004, 11:11 AM
The story of the Hellcat pilot reminds me of one Eddie Rickenbacker told in his autobio. It's been quite a number of years since I read it, so forgive me if I get something wrong.

As he was flying his Spad home after surviving a nasty dogfight, Cap'n Eddie noticed several bullet holes in his windscreen. He thought little of it until he realized that, based on the placement of the holes and apparent penetration angle, he couldn't figure out how the slugs hadn't ripped through HIM, as well.

He spent most of the flight home looking over the makeup of his aircraft and the damage done to it, and just couldn't figure out why he wasn't gushing blood. It didn't dawn on him until he'd landed his crate, shut off the engine, and took one final look at his guns before climbing out of his cockpit.

It was then that he remembered that he had an almost unconscious habit of leaning over to the right so he could peer through the right MG's gunsight, rather than relying on tracers. During a head-on pass, he and a German plane exchanged fire, and the Spandau slugs tore through his windscreen and imbedded in his seat where his neck should have been, except for the fact that he'd moved out of the way.

If you're religious, there's no denying that God was on this man's side throughout the war (he also happened to be grounded with an ear infection during some of the most terrible fighting of Bloody April). If you're not, you still have to agree that he was a pretty lucky guy!

Fennec_P
12-12-2004, 01:58 PM
I remember reading about an occaision where a 109G pilot was attacking a formation of American bombers.

During a stern attack, a 50cal bullet went through the front armor glass, and hit him in the forehead. The bullet was depleted enough that it didn't seriously hurt him, but left a dent in his skull.

XyZspineZyX
12-12-2004, 04:39 PM
Amazing. That seems to establish some kind of limit as to what that glass could stop then, eh?

rbstr44
12-12-2004, 09:44 PM
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by AgentBif:
Aye, but it would be nice to know what thickness can resist what caliber and how dense the stuff is compared to actual armor. <HR></BLOCKQUOTE>

I wonder if there are any books on the subject for equipment on either side? Yes, I have seen some thickness figures on websites/forums for cockpit canopies for a very few planes, but these never seem to include additional data such as material composition.

han freak solo
12-14-2004, 10:31 AM
Just last week on the Discovery Channel here in the USA had on one of my favorite shows "Mythbusters".

That episode happened to have the guys shooting at a variety of items to stop bullets. The most powerful rifle they fired was a 1903 Springfield with .30-06 ammo. The .30-06 bullet (fired perpendicularly) made it through 1" (25.4mm)thick, bullet resistant "glass" from about 30 yards.