"German T-IV tank, camouflaged to resemble a Tiger?" Topic

"It's no secret that PzIV tanks with spaced armour were often mistaken for Tiger tanks. In fact, the similarity between the silhouettes led the Soviets to believe that this was a deliberate deception…."

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Amicalement
Armand

Nonsense. A large number of German vehicles used spaced armor and its original adoption can be laid at the Russian's feet. Spaced armor was originally designed to address weaknesses on German armor to Russian anti-tank rifles.

"It's no secret that PzIV tanks with spaced armour were often mistaken for Tiger tanks.

By whom? Any evidence for this, aside from that photo of a perfectly normal Pz IV?

Every tank the Allies encountered was a Tiger, just ask them.

By whom? Any evidence for this, aside from that photo of a perfectly normal Pz IV?

By that article it was Russians. Typical, if it didn't happen your neck of the war it didn't happen at all.

When we was in the bocage country,

we was assaulted by them Tigers!

Maybe they need better glasses….? (smile)

Amicalement
Armand

Maybe they need better glasses….? (smile)

The Russians did. Their optics were not very good. :-)

The Russians did. Their optics were not very good. :-)

At this point in the war their optics were as good or better than UK and US optics.

Nonsense. A large number of German vehicles used spaced armor and its original adoption can be laid at the Russian's feet. Spaced armor was originally designed to address weaknesses on German armor to Russian anti-tank rifles.

While I agree that it is clear (from German documentation) that the reason for Schurzen was to defend the tank from Soviet AT rifle fire, I do not find it difficult to believe that the Soviets may have thought it was Maskirovka, at least initially.

Schurzen appeared on German tanks about the same time that Tigers were becoming a real menage to the Russians.

And Schurzen plates were not armor-grade steel. They were 5mm thick mild steel plates. Any quick examination would drive one to ask what the heck the Germans thought they could achieve with that. They offered almost no incremental protection from Russian AP cannon fire.

Unless you consider the German goals for Schurzen (inciting wobble in AT rifle rounds before they strike the armor, and pre-detonating HE rounds before they hit the running gear), then Schurzen is kind of hard to explain.

-Mark
(aka: Mk 1)

By that article it was Russians. Typical, if it didn't happen your neck of the war it didn't happen at all.

This is your evidence?

And Schurzen plates were not armor-grade steel. They were 5mm thick mild steel plates. Any quick examination would drive one to ask what the heck the Germans thought they could achieve with that. They offered almost no incremental protection from Russian AP cannon fire.

They were not intended to offer any protection against AP rounds. Tests were conducted against plate and wire schurzen by firing a Russian 14.5mm anti-tank rifle at them from a distance of 100m at 90 degrees. There were no tears or penetration of the 30mm side armour of the vehicle itself. The schurzen even reduced the effectiveness of 75mm HE to the extent that there was no damage to the side armour behind the plates.

On 6 March 1943 Hitler decided, on the basis of these tests, that all new StuGs, Pz IVs and Panthers should have skirts fitted, and that all deployed vehicles of these types should have them backfitted.

Sturmgeschutz & its variants by Spielberger

Yeah, deephorse, that was the reason. As Mark1 puts it the Russians were privy to those test results.

Not sure it was the side skirts that caused the issue but rather turret schurzen (sp?). A hull down Pz IV, or one obscured by brush or smoke, with it's long L/48 gun and muzzle brake looks a lot like a tiger turret. I'm sure that in the chaos and and confusion of battle even more so.

I know I've had to look closely at many photos or BW war films to tell the difference and that's from the comfort of my couch.

I doubt that deception was the reason for skirts. I always thought it had to do with introduction of weapons like the bazooka. In fact didn't the Pz IV J have mesh skirts much like some modern day AFVs use for protection from RPGs? Protection not deception. Deception was an extra benefit.

I doubt that deception was the reason for skirts. I always thought it had to do with introduction of weapons like the bazooka. In fact didn't the Pz IV J have mesh skirts much like some modern day AFVs use for protection from RPGs? Protection not deception. Deception was an extra benefit.

As has been described above in this thread, the purpose of Schurzen was not deception. Not. Deception.

But the purpose was also not protection from bazookas.

The purpose was protection from AT rifles and HE. This is clear from the German documentation. At least as far as I have been able to find in secondary sources.

Most secondary sources on Schurzen point back to the original testing reports from Kummelsdorf in February of 1943. It was based on this test reporting that the orders for Shurzen production and fitting to Pz III and IV, and Stugs, were given.

I have never been able to find an original of the Kummelsdorf reports online. Doesn't mean it's not there somewhere, but if it is I haven't found it.

Perhaps the most widely accredited secondary sources are the various books by Jentz. His books on Pz III, Pz IV, Panther A, and StuG III all provide information from the Kummelsdorf 2/43 testing.

From reading secondary (and tertiary) sources I understand that the 2/43 tests assessed the impact of both 5mm non armor-grade plates, and wire mesh screens, on Russian 14.5mm ATRs at a range of 100m, and on 75 / 76.2mm HE rounds. It is my understanding that no other types of weapons were included in these tests.

These tests were conducted due to the fighting conditions on the Eastern Front in 1942. ATRs (both PTRS-41 and PTRD-41) had become common over the course of 1942. For larger guns there were shortages of AP production in 1942, so it was relatively common for Soviet gunners to fire HE at German tanks. The 30mm armor on the sides of Pz III and Pz IV was shown in combat to be vulnerable to both. As both models were up-armored on the front, the chassis were becoming overloaded, and up-armoring the sides to provide effective protection levels was simply not in the cards for these vehicles.

The findings were that both 5mm steel and wire mesh were effective. The effects on 14.5mm ATR projectiles was to induce wobble so that the rounds side-struck the armor behind, and failed to penetrate. The HE rounds detonated at a distance from the armor, preventing damage to both the interior of the tanks (preventing penetration or significant spalling from non-penetrating HE hits) and also reducing damage to the running gear.

As both plate steel and wire mesh were found effective, it was thought that the lower weight of the wire mesh would be a superior solution. However the lack of rigidity in the wire mesh meant that more complicated mounting mechanisms were needed. So the plate went into production immediately, and the wire mesh skirting did not go into production until more than a year later.

I have never seen a reference to primary source materials of German testing of Schurzen against hollow-charge projectiles from weapons like bazookas, nor against larger AT projectiles.

But, as I stated above, even if the German's purposes for mounting Schurzen are clear, that does not mean that the Soviets knew that. Interestingly it also does not mean that the Americans knew that. At least not at the time. If I saw Schurzen in the first half of 1943, I too would wonder what the heck it was for. Particularly if I was a tanker. 5mm of mild steel over a 30mm plate just would not serve an obvious purpose for me.

So if Soviet observers thought it was a form of Maskirovka, I don't find that any more odd than American observers thinking it was a defense against bazookas. It served that purpose in both cases. But neither reason was why the Germans put it on.

-Mark
(aka: Mk 1)

It's not just induced wobble in the At rifle projectile but it was found that the projectiles, tungsten carbine is very brittle. It tends to emerge from passing through even a thin plate in a damaged condition. In US tests even a 90mm HVAP tungsten carbide projectile passing through only a 1/2" thin plate 12" in front of 6" of armor could reduce the range that it could penetrate the 6" from 2900 yards to just 350 yards.

Interesting data…. thanks!.

Amicalement
Armand

I have never seen a reference to primary source materials of German testing of Schurzen against hollow-charge projectiles from weapons like bazookas, nor against larger AT projectiles.

Mark;

I did find this reference to German testing of Schurzen but, alas, I don't speak German:

AnonymousMay 30, 2013, 7:50:00 PM
hmm yes and now. Maybe today there is an effect with this massive bars. But in WW2 Schürzen almost didnt affect HEAT shells at all. The german WaPrü Amt tested it in 1944 with german Panzerschrecks and -fäusten and wiremesh and 5mm steel sheet Schürzen were almost total useless.

German quote: (Sorry i am to lazy to translate :P)
Am 21.12.1944 wurde in Kummersdorf ein Versuchschießen durchgeführt, allerdings nur mit den Schürzen aus Maschendraht und Panzerfaust bzw. -schreck. Ergebnis: "Das Verhältnis der beschleunigten Masse beim Auftreffen zur Masse der Schürzen, die durch ihre Trägheit das Geschoß bremsen sollen, ist derart unterschiedlich, daß die Schürze die Geschoßwirkung nur unwesentlich beeinflussen kann. Alle Schürzen sind mit der Aufhängevorrichtung beim ersten Schuß zerstört worden." Auch wenn die Schürzen aus 5mm Blechen und nicht aus harten Drahtnetz sind, wird die Wirkung der Hohlladunggeschoße nicht bzw. kaum gemindert, wobei die allierten Hohlladungsgeschoße in ihrer Wirkung den dt. nicht nachstanden. D.h. die dt. Schürzen waren unwirksam, behinderten das Fahrzeug, teilweise sogar den Höhenrichtbereich des Geschütze, waren nicht sicher befestigt und eine Verschwendung von Material."

Source: Karl Pawlas "Schürzen zur Verstärkung der Panzerung" in Waffen Revue Nr. 40, S.6457ff

And here is a link to the original, one needs to scroll down to 6457

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I did find a brief summary of this in another source in English which seems to echo that the tests showed almost no effect against shaped charge weapons like the panzerschreck.

I do know several folks here are very fluent in German and perhaps can summarize for the rest of us.

Marc

Many thanks!.

Amicalement
Armand

Needs some cleaning up, and for apron read skirt, but I think the gist is clear (courtesy of google translate)-

On 21.12.1944 a trial shooting was carried out in Kummersdorf, but only with the aprons made of wire mesh and Panzerfaust or -schreck. Result: "The ratio of the accelerated mass when striking the mass of the aprons, which are to slow the projectile by their inertia, is so different that the apron can affect the projectile effect only insignificant. All aprons have been destroyed with the suspension on the first shot. " Even if the aprons are made of 5mm sheets and not of hard wire mesh, the effect of the shaped charge floors is not or hardly diminished, the allied shaped charge floors in their effect did not dt. That the German aprons were ineffective, obstructing the vehicle, sometimes even the upright range of the guns, were not securely fastened and a waste of material. "

Interesting info on the further WaPruf Schurzen tests. Seems like there is a fair bit of info in there that does not quite map directly. I'll be interested to see if any of our German speakers can add to the translation.

I'm somewhat surprised that the Germans seem to have concluded that Schurzen didn't help against hollow-charge weapons. I have results of a firing test conducted by 5th TD Group command using a US bazooka against a Panther, and while it does not test Schruzen specifically, it does seem to demonstrate that almost anything in front of the main armor could lead to a failure to penetrate.

This is an illustration from the report, showing locations of the hits.

Findings on the various hits include:

a. Ricochet into wheel rim completely severing the tire and blasting an 8" hole in the wheel. There was no damaging effect upon the inner wheel immediately behind the one hit.
b. Direct hit upon a wheel. A 3 x 5" hole was blasted out of the wheel and two 10" radial cracks were made. There was no damaging effect upon the wheel immediately inside the one hit.
c. & d. Direct hits upon wheels. 6" diameter holes blasted – no effect upon inner wheels.

…

j. A hit upon the towing-jack device on the rear of the tank. A small portion was chipped away, but there was no effect upon the armor plate.
k. A hit upon one of the exhaust pipes, completely blasting it away, but there was no effect upon the armor plate inasmuch as the blast had been dissipated upon the exhaust pipe.

…

p. A hit upon the towing hook on the front of the tank. No damaging effect upon the armor plate.

The purpose of the test was to figure out what parts of a Panther to shoot at with the bazooka. So the conclusions are all about where to shoot, not about the effect of obstructions. But the effect of the various obstructions is pretty clear from the description of the many hits. Most hits on the armor itself penetrated (except for some that ricocheted rather than detonating on the plate, including all hits on the front slope, which was sloped enough to ricochet the projectiles in the test). But every hit described as striking an obstruction spaced away from the plate failed to penetrate.

I find the descriptions of hits on the road wheels particularly interesting. These would not have been armor grade steel, and served effectively in the same role as Schurzen for the lower hull side. Not only did bazooka rounds that detonated on the road wheels not penetrate the hull side, they didn't even penetrate the inner road wheels!

Well, it's all in interesting set of material, at the very least. Not sure exactly what to conclude from it all.

-Mark
(aka: Mk 1)

From the various articles on the effectiveness of spaced armor it looks like the German tests had mixed results. In the first test they used their own Panzerfausts. But these may have been more effective than the Bazooka or Piat. And the standoff distance may have been such that the space distance may have been a detriment for the smaller caliber warheads and not the larger Panzerfaust.
Someone mentioned the optimum standoff distance was a multiple of the diameter.

The bazooka was quite sensitive to angle of impact.
Anything but a head on strike on flat plate could mean failure to go off or penetrate.
It's possible this explains some of the effect of striking a road wheel.

Ww2 shaped charge weapons were nowhere near as effective as more modern designs.

'The ratio of the faster striking mass to that of the skirts, whose inertia is supposed to slow the projectile, is so different that the skirts impinge only marginally on the effect of the projectile. All the skirts were destroyed along with the suspension by the first shot. Even if the skirts are of 5mm sheet and not hard wire mesh, the effect of hollow charge projectiles is reduced barely or not at all, the allied hollow charge projectiles not lagging behind the German in their effect. That is, the German skirts were ineffective, obstructed the vehicle, sometimes even the elevation capability of the gun, were not securely fastened and a waste of material.'

Based on that I'm surprised they bothered…

Based on that I'm surprised they bothered…

They didn't. The skirts were for AT Rifle protection and they just tested them against HC projectiles to see if they worked against them as well.

I've been working on variable HEAT penetration for my game. I have the armor angle ricochet effect mostly solved but I need to get the standoff distance effects determined.

It seems to me spaced armor and sandbags will increase penetration effectiveness of WWII HEAT rounds.

I got this from the Tankograd site:
link

The drawing shows the depth of penetration of a 100mm shaped charge increasing to 700mm (7 CD) when the standoff distance is increased to 0.6 meters, but the penetration drops down to less than 400mm at a standoff of 1.2 meters, less than 200mm at 2.4 meters, and less than 50mm at 4.8 meters.

link

The normal achievable penetration of the 100mm diameter warhead would probably correspond to the penetration at a 15cm standoff distance or less, since the typical built-in standoff for a rocket-delivered shaped charge warhead with a typical pointed aerodynamic fairing without a standoff probe or a spike tip is usually less than 2 CD. As you can see in the chart, an additional 0.45 meters of space in front of the built-in standoff yields the best penetration obtained from the warhead, and this helps to communicate the peculiarities of shaped charges: spaced armour can be effective, but only when integrated in a complex armour configuration or with a sufficiently large air gap. For example, if an APC with a ~400mm-wide track had a simple sheet metal or rubber side skirt installed to cover the suspension, it would actually become even more vulnerable to a shaped charge grenade due to the increased standoff. Even at 30 degrees, the side skirts of a typical tank would not provide sufficient spacing to defeat a tank-fired HEAT shell. Because of this, the primary incentive to install simple side skirts on tanks is to reduce the amount of dust kicked up into the air by the tracks, mainly to prevent the enemy from spotting the tank from faraway distances and also to improve the visibility for other tanks at the back of a convoy. Protection from shaped charges would not be one of the reasons unless the side skirts were thick armoured panels such as on the M1 Abrams, or if they were a mounting platform for reactive armour.

Wolfhag

Actually a better although much looser translation of the first part of that extract would be

'Compared to the mass of the skirts, whose inertia is supposed to slow the projectile, the mass of the accelerated round is so disproportionately large that the skirts only marginally alter the projectile's effect. All the skirts were destroyed, along with the suspension, by the first shot. Even if the skirts are of 5mm sheet and not hard wire mesh, the effect of hollow charge projectiles is reduced barely or not at all, the allied hollow charge projectiles not lagging behind the German in their effect. That is, the German skirts were ineffective, obstructed the vehicle, sometimes even the elevation capability of the gun, were not securely fastened, and were a waste of material.'

This first sentence is basically a Newton's Second Law point. The writer is emphasising that compared to a shell of mass M coming at velocity V, the static mass of a flimsy set of skirts is so teeny that it's negligible. Effectively, when the incoming hits the skirts anywhere, it dumps off its energy into them and wrecks them. Probably this sense is more obvious from reading the rest of the source.

Stand off and heat is tricky stuff.
Modern bar (slat) armour is intended to deflect the physical round most of the time. They don't go off or the head is deformed or pointing in the wrong direction before they do.
My understanding is that should the warhead somehow manage to strike a bar dead on at 90 degrees then it could go off and the stand off alone isn't enough to protect light armour.

The focussed spray thingummy from modern heat is way longer than ww2 era rounds though.

Sandbags.
It does seem sandbags or logs could have improved the effectiveness of some heat rounds. Despite crews hopes of extra protection.

I've found players unenthusiastic about seeing this simulated but YMMV.

Dust suppression wouldn't explain the 8mm panels surrounding the turret.

So what's the general consensus opinion for WWII HEAT versus side skirts?

1- Side skirts provide protection decreasing penetration X%

2- Side skirts provide no protection

3- Side skirts enhance HEAT penetration X%

Wolfhag

Most players expect 1) in my experience.

What I can't fathom is what the effectiveness of side skirts has to do with Pz IVs being mistaken for Tigers??? Were they any more or less mis identified because the skirts worked or didn't work?

Good Grief Charlie Brown!!!

Yes, this has been well and truly derailed. And what about option #4, "it's really not an issue in the games I play"?

deephorse,
I'm looking for an opinion on a technical issue, not taking a survey on who would use it as a rule. There are people here that know more about this stuff than I do.

Wolfhag

Every tank the Allies encountered was a Tiger, just ask them.

"With the scattered reports of tanks on our fronts during the last 48 hours, it is interesting to report that an enterprising Intelligence Officer who came upon a knocked out Panther Tank behind our lines stood by it for awhile and asked a number of passers-by what kind of tank it was. Without exception they replied "Tiger"."

2 Canadian Corps Intelligence Summary No. 3, page 1.
PDF link

Normandy War Diaries: link