Friday, 10 May 2013

Soviet Armour Quality

I've been focusing on German armour a lot, so it's only fair that I look at the quality of Soviet tank armour for a little bit. As we've seen, German armour quality post 1942 is quite brittle, with lots of spalling, cracking, and fragmentation going on. Let's see what Soviet armour is like in that regard.

CAMD RF 38-11355-785

In the NII-48 report "Penetrations of T-34s and reasons for their losses", a large number of knocked out T-34s were examined, for, as you may have guessed it, reasons why they no longer work. As well as offering a very interesting breakdown of calibers and impact locations, it also offers an analysis of armour quality. Let's take a look.

"6. Comments on the quality of armour on the T-34.

Existing data on impacts allows us to conduct an analysis of the armour used on the T-34. Table #25 shows information on the type of impact, and the caliber responsible for the impacts, in percentages."

The first line is "safe impacts", or non-penetrating hits. 54.1% of hits do not penetrate the T-34, this is pretty good. The rest of the line breaks it down by caliber: 3.2% by 20 mm shells, 6.8% by 37 mm shells, 4.9% by 42 mm shells, 30.6% by 50 mm shells, 3.2% by 75 mm shells, 0.2% by 88 mm shells, 2% by 105 mm shells, and 3.2% from indeterminate sources.

The next section is the one we can judge armour quality by. 42.0% of the impacts were clean penetrating hits. Only 2.1% of the hits were ragged (indicating impurity in the steel), 0.6% had cracks, 0.6% led to spalling, and 0.6% had fragments fall off. This is pretty good! The analysis agrees.

"It can be seen from the table that the percentage of brittle impacts (ragged penetrations, cracks, spalling, fragementation) is very small, 3.9%. Most of the brittle impacts are from artillery calibers greater than 50 mm, and from unknown sources, which could be bombs, grenades, mines, etc. Overall, the quality of armour is satisfactory. Judging the armour's resistance is not possible, since the ranges and angles of impact are not known."

NII-48 explores the topic in that last sentence in a different paper, and it will be the topic of another article.

19 comments:

  1. Good article, Peter, but I would like to know when was the document printed.

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  2. The report was prepared in September/October of 1942.

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  3. I think the overall ratio of clean penetration is 42.0, not 42.9. The number doesn't add up.

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  4. What's the difference between ragged/spalling/fragmentation exactly?

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    1. A ragged penetration is much larger than a caliber in size. A spalling it is when armour is not penetrated, but fragments of the armour fly off the other side and damage the crew and components. That last one is when the armour plates crack and fall off as a result of being hit. All are indicative of over-hardened or poor quality armour.

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  5. What year was this examination done?

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    1. I've been 11 year later to this topic and 7 years later to this comment, but I'll post it anyway. Do you have more studies about soviet tank armor quality regarding other years of the war or just this one? I've a found a lot about german armor quality here, but not enough on the soviet side or the allied side unfortunately.

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    2. They're scattered throughout the blog, usually under the metallurgy tag. Sadly none are quite so comprehensive.

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  6. Peter, another question, if you could answer it, I would appreciate. Would you say the german armor quality in 1942 was of better quality, like the ones used in the manufacture of the Panzers IV Ausf. G, compared to panzers built in 1943-1945?

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    1. The requirements for German armour (chemical composition, hardness, etc) changed several times in 1940-1945 to make up for shortages of strategic metals. As time passed the crumbling German industry also had a lot of issues meeting those requirements. The British had quite a low opinion of German tank armour with the Pz.Kpfw.III and Pz.Kpfw.IV back in 1941 and Soviet trials in 1940 revealed a disastrously poor armour quality, so it's hard to say at what time the certain threshold was crossed. I think that a randomly picked tank from 1941 would likely beat a tank from 1945 in armour quality, but it would not be impossible to find a tank with good armour in 1945 and a tank with bad armour in 1941.

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  7. I see, thanks for the answer. Recently, I came across 2 pieces of informations talking about the good quality of armor of the Tiger I, one is from "The Tiger Tank and Allied Intelligence - Volume IV: Capabilities and Performance" of Bruce Oliver Newsome and a recent article in "TankHistoria" website ("Tiger I vs 17-Pounder Firing Trials"), what is interesting, aside of all the informations available in both, is that they talk about the quality of the armor of the Tiger, comparing with the Panther, saying that, regarding armor quality, it did not suffer from the same problems as the Panther. Obviously, as we know, there were Tiger Is with flawed armor and Panthers with good armor, but what I take from these informations is that the probability of having a Tiger I with good armor quality was higher than having a Panther with good armor quality.

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    1. Blanket statements like these are usually incorrect. In this case both Soviet and British trials found Tigers with very poor armor. Quality could vary greatly not just between tanks but between different plates on the same tank.

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  8. Ok, I thought a higher percentage of Panthers suffered from poor armor quality when compared to the Tiger I.

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    1. Probably, unfortunately no one was testing a statistically significant quantity of any tank to establish that.

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  9. Right, Peter, thanks for your answers, I've been trying to learn as much as I can about WW2 era armored fighting vehicles, your website and tons of books are helping me out. I'm an amateur historian focused on ww2 for a long time, but lately the topic about AFVs is intriguing me.

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  10. Peter, if you don't mind answering one more question, sorry for this. But, I've seen your video in your youtube channel, the "IS-2 vs King Tiger: Which one had the stronger gun?" and you said that in one of the trials they used a KwK 43 instead of a Pak43, is there any difference at all in performance between these two or they are the same?

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