Armor quality of the Tiger I

[Michael Kenny]

[Michael Kenny]

In German tests, the criteria for failure was if you were able to see light shine through the crack.

A crack is a simple well-understood term. Redefining it does not make it 'not' a crack.
The key is would such damage result in return for factory rebuild?

your photo caption states the Tiger was hit by two HE strikes. Were they from a 25 pounder gun, or something even heavier?

Jentz does not elaborate.

[Michael Kenny]

What you wrote was wrong.

'Wot I wrote' is correct. (see Eric Wise) The side panel on the Tiger is plainly, clearly and obviously cracked.

[seppw]

What you wrote was wrong. A 2mm deep crack is not the same as a 82mm deep crack. What we can see in the picture you posted is usually described as flaking. Just like we would write "In a particular set, in which Panther tanks were hit from all angles (including the sides), 75% of the shots penetrated" instead of "75% of all hits on a Panther penetrated" in a discussion about frontal attacks. Assuming we are trying not to confuse other members and push our agenda that is ofc....

[Michael Kenny]

[seppw]

In German tests, the criteria for failure was if you were able to see light shine through the crack.

A crack is a simple well-understood term. Redefining it does not make it 'not' a crack.
The key is would such damage result in return for factory rebuild?

A crack is indeed a simple and well-understood term. The question is: Would we say "Plate X is cracked", if merely the surface had a shallow crack or would we say only use that phrase if the crack went throught he entire plate at atleast one point?
Another question is: Who would use this ambigious and confusing phrase if the effect at hand can be easily and distincly described as flaking?

[Michael Kenny]

Another question is: Who would use this ambigious and confusing phrase if the effect at hand can be easily and distincly described as flaking?

Let the readers decide if this is flaking or a crack.

[Yoozername]

Not sure if I posted this already to the thread. Video shows a Tiger I being shot up by british later in the video...

https://www.youtube.com/watch?v=44IWaZrBcXo

[critical mass]

Notice the presence of "petals" around all the impacts. Petals only form in very ductile failing modes of armor. This was probably aided by the penetrator geometry and quality (capped and pointed nose, enhancing ductile failing modes) as well as by the rather high ambient temperatures while staging this test (not yet within the brittle temperature range of the target material).

Yeah, that definitely looks like an instance of frontal petaling. Given the T/D ratios involved, thats not so surprising. I'm guessing the 6 pdr shots were all made at close range and from 0 degree obliquity. Whats the maximum range that the 6 pdr L52 gun could penetrate a Tigers front armor? 400 meters, 500 meters?

Since we're on the subject, I'd like to ask you a question about crew survivability. In general, CM, can it be said that spalling from non-penetrating hits is less dangerous than ductile hole growth and petaling failures?

The maximum range a 6pdr will penetrate the TIGER1 front depends on the projectile quality in question. Short range requires high striking velocity. A good quality projectile will stay intact or break up late during the perforation, while a poor quality projectile will shatter leaving only a dent.

You can figure quality simply as kind of a velocity, at which severe change of shape mechnics start to affect the projectile. This velocity gets modified by other factors, like f.e. increase of T/D ratio or obliquity will LOWER the critical velocity, while the presence of a cap or softer armor will INCREASE it.
It´s one of the aspects least easily studied and while we do have information on events, we have little data on the span of variances. For that reason, it´s in my opinion not reliable to give a discrete range.

I have not enough information at hand to judge the lethality of different failure modes. It´s possible that such studies were attempted but they didn´t cross my path. What I understand is that the germans wanted to resist penetration partially because their use of delay patterned HE filled AP. They expected the Pzgr to explode or fragmentate inside the target, after penetration. Such a damaging event is best countered by lowering the probability to affect full perforation in the first place. Ductile failure modes usually come in with the disadvantage that the armor needs to be on the softer side, thus, allowing somehow easier penetration.

It´s interesting that the report does state that german homogenious armor was on par with british MQ armor at normal impact but considerably better at obliquity. This, too, is reflected by the german procedure of testing armor in relation to critical obliquity in ° at fixed velocity, not to velocity in fps at at fixed obliquity (normal). A considerably difference between german projectile and armor acceptance specifications.

[Michael Kenny]

The loss of the entire hull side is not an uncommon sight.
https://youtu.be/44IWaZrBcXo?t=507

SS 102 Tiger 231 Ussy (2).jpg (137.2 KiB) Viewed 2752 times

Two views of same Tiger above.
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Toiger wreck Russia . . . (2) hull side missing v.jpg (32.67 KiB) Viewed 2752 times

[critical mass]

Notice that in all cases the plate was dislodged completely from the hull. This points towards the possibility that the connection between hull and plate was somewhat intentionally designed as a weak path in order to predefine a more benign failure path in damaged condition.
Propellant is stored in these sponsons and if the burn can vent early, there is no large pressure build up and the burning rate will remain sufficiently low as to preclude catastrophic overpressure. An intentionally weak plate connection here will contribute to venting outwards rather than invards to the turret, particularly past the choke point of pressure build up. Propellant fires are exercises of gradual to rapid pressure increase. For openings not specifically designed to pass gas efficiently the rate of flow will be quite high until the gas becomes supersonic, at which point the vent tends to 'Choke‘. Past that point, the pressure builds up rapidly to the point of critical failure- either this connection fails or the turret get blown out.

[Yoozername]

In any case, the penetrations by the 'Archer' seem fairly clean. Maybe it fired an APDS at turret? Regular AP at side armor.
The side armor appears to have a variable thickness with the top part being thicker.

If I were to design a failure mechanism such a CM describes, it would be a blow-out but downward such that the thinner plate above the tracks gives way. It would really need that the ammo was in some sort of sealed bin.

More than likely, that tiger might had had some weld/plate damage already, and the opposite side penetration impacted that plate from the inside, and it's weight dropped it.

[Avalancheon]

Jentz does not elaborate.

Its a relevant question, because there was at least one instance when a 25 pounder gun knocked out a Tiger tank from the flank.

''The 25-pounders opened fire first at short range, and hitting a Tiger in the side, the shell went through, setting it on fire.'' -Tunisian Battle, by John D'Arcy-Dawson.

Its probably not the same vehicle, because the British test reported that their Tiger was not burned.


BTW, the 6 pounder shots against the Tigers front plate were fired at a muzzle velocity of 2675 to 2925 fps, and struck at a velocity of 2350 to 2380 fps. Do you know what range that corresponds to?

[Yoozername]

This image shows the effects of an internal ammunition explosion. The area has a 4 round rack for 88mm ammunition. Almost certainly there was some HE rounds there. A propellant 'explosion' would not cause this extent of damage. The blast rips away the roof and also the thin armor above the tracks. Apparently cutting the track and damaging a roadwheel. I would imagine any crew would be dead or severely wounded. This Tiger may have been low on ammunition, and it did not have extensive internal fires.

[Avalancheon]

This image shows the effects of an internal ammunition explosion. The area has a 4 round rack for 88mm ammunition. Almost certainly there was some HE rounds there. A propellant 'explosion' would not cause this extent of damage. The blast rips away the roof and also the thin armor above the tracks. Apparently cutting the track and damaging a roadwheel. I would imagine any crew would be dead or severely wounded. This Tiger may have been low on ammunition, and it did not have extensive internal fires.

Yeah, it looks like the explosion resulted in the bursting of one of the hulls weld seams. Do you know where this picture was taken from?