Shurzen

[DRG]

It's not like ERA and I've already explained what I'm going to do

Don

[PanzerBob]

For my 2 pfennings worth, I wasn't involved in the previous disussions. Two thoughts occur, what about the screen type Shurzen in the latter part of the war, it would seem these were not aimed at ATR's but HEAT rounds? As well how many Panzers and StuG's actually retained their Shurzen once in battle, their seems to be a lot of photos that show some if not all missing. The Soviets even took to mounting bedsprings at least on some tanks. I have to wonder whether these measures were more to give the crews some sense of protection, as the addition of sandbags and tracks did for the crews using them.

Just some thoughts, Bob out

[chuckfourth]

Hi Claus
Very interesting, here is something relevant from
http://www.globalsecurity.org/milita...ped-charge.htm

"A Monroe-effect shaped-charge warhead can be expected to penetrate armor equal to 150-250% of the warhead diameter. "

All WWII HEAT munitions are 'simple' Monroe effect types. So the -theoretical maximum- range/effect against armour plate of any of the WWII munitions is 2.5 times the Munitions diameter.
This is because
"At larger standoff ( >2.5*WH diameter), the jet is broken into many small particulates".(See 1) ie its become straightforward HE blast

So the maximum space a bazooka HEAT can cross and still have its armour penetrating jet effect is 2.36 * 2.5, thats 5.9 inches. Any further and the jet has lost its focus and is more akin to blast than blowtorch.

Now PZ IV track width is about 15 inches so the schurtzen side plate is at least 15 inches from the lower hull.
Looking at pictures its clear that the upper hull and turret is at least 11 inches behind the schurtzen plate.
see for example
http://www.steeldragons.net/PanzerIVbuildpageone.html
So shurtzen is clearly far enough away from the armour proper to protect 100 per cent from bazooka and PIAT.

If we work this in reverse we get what the HEAT value of the schurtzen should be
lets say the shurtzen plate is a very conservative 11 (28cm) inches from the hull, we get
28 / 2.5 = 11.2
So Schurtzen should have minimum HEAT armour value of 11, assuming that the HEAT round is working at its theoretical maximum and youve hit part of the shurtzen that is in front of close armour, not in front of the lower hull for instance.

Looking at some HEAT rounds that were in use if we divide the penetration by W/H diameter we get a good idea how far from the theoreticl maximum of 2.5 the pratical penetration ratios were.
German 61mm rifle grenade is 126/61 = 2
Bazooka is 4.7/2.36 = 2
PIAT is 75/88 = 1.1
Panzerfaust 60 = 200/140 = 1.4

Yes Yes I realise some of this has been posted elsewhere. its here for ease of access.

(1)
http://www.globalsecurity.org/milita...2-warheads.htm

Best Regards Chuck.

[PopskiPPA]

The effect of Schürzen vs HEAT has been discussed hundreds of times.
I'm wondering why nobody asked the real question regarding Schürzen in all these years:
Do Schürzen protect against anti tank rifles in-game?

Everybody (almost) agrees Schürzen were originally designed to defeat russian anti tank rifles, the protection against HEAT was an unexpected benefit.
A quick search showed no increase in steel armor for tanks equipped with Schürzen in-game.
Is there a reason for this?

[Imp]

Seems heated debate this but I will chuck my 2 penneth in with Panzer Bob.
It was easily damaged, a trip into the trees for instance so should not be modeled as complete vulnerability even if it is as parts could be missing.
So if stopped the majority the others could be considered to strike an exposed area

[iCaMpWiThAWP]

Originally Posted by PopskiPPA

The effect of Schürzen vs HEAT has been discussed hundreds of times.
I'm wondering why nobody asked the real question regarding Schürzen in all these years:
Do Schürzen protect against anti tank rifles in-game?

Everybody (almost) agrees Schürzen were originally designed to defeat russian anti tank rifles, the protection against HEAT was an unexpected benefit.
A quick search showed no increase in steel armor for tanks equipped with Schürzen in-game.
Is there a reason for this?

I don't think so, Schürzen in fact WAS designed to defeat ATRs, but in game the only defense against AP,HE,and SABOT rounds is steel armor, as there's no "side skirts" armor in the game.

[cbo]

Originally Posted by PanzerBob

For my 2 pfennings worth, I wasn't involved in the previous disussions. Two thoughts occur, what about the screen type Shurzen in the latter part of the war, it would seem these were not aimed at ATR's but HEAT rounds?

Nope, both types of Schürzen were designed to defeat ATR rounds. When tested in February 1943, both the solid plate and the wire-mesh types were tried out and both worked against ATRs. The solid plates were choosen, because the brackets for the wire-mesh type was not ready. Later, that problem was solved and the wire-mesh type introduced as a weight saving measure, AFAIK

The Soviets even took to mounting bedsprings at least on some tanks. I have to wonder whether these measures were more to give the crews some sense of protection, as the addition of sandbags and tracks did for the crews using them.

AFAIK the "bedsprings" were in fact specially designed anti-HEAT shields, the purpose being to catch the slow moving PzFaust wearhead without detonating it. The distance between the shield and the main armour was insufficient to prevent penetration if the round went off.

Claus B

[cbo]

Originally Posted by chuckfourth

Hi Claus
Very interesting, here is something relevant from
http://www.globalsecurity.org/milita...ped-charge.htm

"A Monroe-effect shaped-charge warhead can be expected to penetrate armor equal to 150-250% of the warhead diameter. ".

This is far to simplistic a statement. Penetration can be a lot more and a lot less depending on design, liner material, quality of manufacture, coneshape and what not.

So the maximum space a bazooka HEAT can cross and still have its armour penetrating jet effect is 2.36 * 2.5, thats 5.9 inches. Any further and the jet has lost its focus and is more akin to blast than blowtorch.

Again, far too simplistic and you seem to be confusing standoff with penetration?

Reality is that penetration varies with stand-off. Some figures from Journal of Battlefield Technology suggest that a HEAT warhead with a steel liner (as most WWII rounds, AFAIK) would penetrate 2.8 cone diameters with a standoff of 1.0 At 3x standoff, penetration would rise to 3.5 conediameters, then dropping back to 2.1 cone diameters at 6x standoff.
This is of course a simplifaction and penetrations would probably apply more to post-war rounds than the WWII items, but it does show that the relationship between standoff and penetration is a complex one.

Now PZ IV track width is about 15 inches so the schurtzen side plate is at least 15 inches from the lower hull.
Looking at pictures its clear that the upper hull and turret is at least 11 inches behind the schurtzen plate.
see for example
http://www.steeldragons.net/PanzerIVbuildpageone.html
So shurtzen is clearly far enough away from the armour proper to protect 100 per cent from bazooka and PIAT.

The problem with these idle speculations is that they dont fit with reality. Note the British test showing that the PIAT could, on a good day, in fact penetrate a 6mm plate, reach across 50cm of space (that's about 20") and still penetrate a 32mm armour plate.

This is exactly why circumstantial evidence like hits on Panther roadwheels and speculative arithmatic is not sufficient evidence to warrant changes to the game - in my view.

You need the results of actual tests with the actual weapons involved if you want to come anywhere near the truth of the matter. And note, that even the British ordnance people doing these tests did not think that they were conclusive!

Claus B

[Imp]

The only other thing I will add is while it may have been origionaly designed to stop ATR the Germans would have realised just as the allies did the benefits against HEAT

[PanzerBob]

Originally Posted by cbo

Nope, both types of Schürzen were designed to defeat ATR rounds. When tested in February 1943, both the solid plate and the wire-mesh types were tried out and both worked against ATRs. The solid plates were choosen, because the brackets for the wire-mesh type was not ready. Later, that problem was solved and the wire-mesh type introduced as a weight saving measure, AFAIK

AFAIK the "bedsprings" were in fact specially designed anti-HEAT shields, the purpose being to catch the slow moving PzFaust wearhead without detonating it. The distance between the shield and the main armour was insufficient to prevent penetration if the round went off.

Claus B

Thanks Claus, certainly makes sense, and certainly explains what he idea behind the "bedsprings" was. Interesting how decisions made can have effect all out of perpective to the orginal intent. The Soviets retained their ATR's when other forces had dumped them. Figuring any weapon was better than none and they would at least usefull against light armoured vehicles. The result was causing the Germans to waste even more resources defending against them and causing the invention or at least the first particial stand-off armour. And people question how can WWII history can remain interesting!!!???

Bob out