Sunday 1 September 2013

Guderian on German Armour

I have previously pointed out that the quality of German armour degraded sharply over a relatively short amount of time. But when did it start? Early war vehicles exhibit excellent armour ductility, but the late war ones, not so much. Since it's impossible to grab samples of the produced armour, I'm going to have to rely on second-hand information. Thankfully, a rather reputable figure speaks on the subject!

"In November of 1941, high ranking engineers, industry representatives, and armament directorate officers came to my tank army in order to familiarize themselves with the Russian T-34 tank. Frontline officers suggested that we should build tanks exactly like the T-34 in order to correct the unpleasant position of our armoured forces, but this position did not receive support from the engineers. Not because they were opposed to imitation, but because it was not possible to rapidly set up manufacturing of important components, especially the diesel motor. Additionally, our hardened steel, whose quality was dropping due to a lack of natural resources, was inferior to the Russians' hardened steel."

H. Guderian, "Panzer Leader", page 268

Interestingly enough, Daimler-Benz decided to imitate the T-34 anyway, with domestic components. The result proved complicated and unreliable, and lost out to the MAN prototype in competition for the Panther project.


  1. "hardened" steel. What does he mean?
    The germans used either homogenious armour or -later- homogenious with subsequent special surface treatment (Einsatzhärtung).
    Face hardened armour was -to my knowledge- never used on tanks but exclusively on major naval vessels.

    1. Conventional steel that you will find in a pot or something is not particularly hard or resistant to projectiles. Armour steel is much harder, but you can have a range of hardening for various properties. Very hard steel resists undermatching projectiles better, but fails catastrophically when hit by overmatching projectiles. The better you are at hardening armour, the less faults it will have and the less likely it is to fail when hit.

    2. Hardened plate is better at resisting uncapped AP shot as used by the Soviets, while RHA is better against capped shot used by the western allies. Hardened plate fails by shatter when defeated. Overmatched projectiles perform better against sloped armour, whether it is hard or soft.

  2. It has to do with the alloy in the armors. Particularly steel with a high manganese content, and as the war went on Thyssen was unable to secure that quality steel. So to make up for the lack of manganese the carbon content was likely raised which allowed it to be hardened, but lacked the ductility of armor plate. Comparing brinell readings isn't enough in these cases, it is entirely possible to have two plates with identical hardnesses while one is very elastic and another is crystalline like glass.

  3. The high brinell hardness of some soviet armor was a point of failure due to increased spalling with the limited volume of nearly all Tanks spalling is bad, but in the VERY compact fighting compartment of the T34 it is even worse

    1. You can get away with higher harnesses if your alloy supports it. Soviet alloys did, German ones did not.

  4. Your assertion is demonstrably false. I own a copy of Panzer Leader, 1952 printing. It say no such thing, on p.268 or anywhere else. In fact, it's December on p.268. You should have tried to stuff your made up quote on p.248.

    I have no problem with the notion that Russians could possibly be good at something. They have many scientific and engineering accomplishments to their credit, and while their WWII armour varied greatly as far as flaws, when it was good it seems to have been very good. But shame on you for fabricating history to try and prove your thesis.

    1. Hm ever think that different printings of the book might have different pages sizes? Shocking, I know.

      Also my quote is translated from the Russian version of the book, so the text might not be exactly the same.

    2. It's the second paragraph of chapter eight, if you actually care.

  5. Yes, I do actually care. My objection was based solely on a dedication to accuracy and truth. As I said, I have no emotional or idealogical objections to the Russians doing well at something. It's well known that Guderian had a high opinion of the T-34, thought it superior to Pz.IIIs and IVs, and would have preferred to use them.

    With your new directions I found the quote, in a place later in the book than I was looking. As regards the charge of fabricating the quote, my apologies. However, as you suggested, the quote in the English version is not identical:

    "As already stated, a group of responsible designers, industrialists, and officers of the Army Ordnance Office visited my Panzer Army in November 1941, with the object of studying first hand our recent combat experience when fighting the superior Russian tank, the T34, and of deciding what measures should be taken to help us regain technical supremacy over the Russians. The officers at the front were of the opinion that the T34 should simply be copied, since this would be the quickest way to put to rights the most unhappy situation of the German panzer troop: but the designers could not agree to this. This was not primarily because of the designers' natural pride in their own inventions, but rather because it would not be possible to mass-produce essential elements of the T34-in particular the aluminium diesel engines-with the necessary speed. Also, as far as steel alloys went, we were at a disadvantage compared to the Russians owing to our shortage of raw materials."

    Seeing a noticeable difference, I decided to seek out a German copy. From it we have:

    "Wie bereits erwähnt, besuchten die maß gebenden Konstrukteure, Industriellen und Offiziere des Heereswaffenamtes im November 1941 meine Panzerarmee, um sich an Ort und Stelle und an Hand der frischen Kriegserfahrungen gegen den überlegenen russischen Panzer T34 über die Maßnahmen klar zu werden, die uns wieder zur technischen Überlegenheit über die Russen verhelfen konnten. Der Gedanke der Frontoffiziere, den russischen T 34 nachzubauen, um auf schnellste Art die außerordentlich unglückliche Lage der deutschen Panzertruppe zu bessern, fand bei den Konstrukteuren keinen Anklang. Hierfür war wohl weniger die Eitelkeit des Erfinders ausschlaggebend, als die Unmöglichkeit, mit der erforderlichen Schnelligkeit wesentliche Bestandteile des T 34, besonders seinen Aluminium-Dieselmotor nachzubauen. Auch in der Legierung des Stahls waren wir durch Rohstoffbeschränkungen den Russen gegenüber benachteiligt."

    I sat down and translated it, and got this:

    "As already mentioned, the authoritative designers, industrialists and officers of the Army Ordnance Office visited my Panzer Army in November of 1941, at the point and place themselves and having at hand the fresh war experience against the superior Russian tank T34 with regard to the measures best to take, that could help us once again attain technical superiority over the Russians. The idea of the front-line officers, to replicate the Russian T34, as the fastest method to improve the extremely unfortunate situation the German panzer troops found themselves, found in the engineers no response. This was not so much an outpouring of the conceit of the inventors, but the impossibility, to recreate with the necessary speed the essential components of the T34, particularly the aluminium diesel motor. Also in the shortage of raw materials put us at a comparative disadvantage to the Russians in the alloying of steel.”

  6. Now, from both the English, and my translation of the German, I gather a somewhat different notion that you. Clearly, the tank is regarded as excellent. However, the inability to reproduce the engine, presumably because of the aluminium, is regarded as the primary problem. As a secondary concern is that they cannot replicate the steel alloy. This does not necessarily establish that the Germans are producing low quality steel at this point, and data elsewhere from Jentz and Livingston has not shown as much either. Rather, German steel seems to have steadily declined through the war, contrary to the bizarre statement from the Americans on the other page. What Guderian's quote does establish is that the T-34's armour was made of a superior alloy, that the Germans could not replicate due to lack of materials. Now, data I have seen on Russian armour, as information that has been shown on other pages here entirely substantiates that this was so: the Russians were using excellent steel compositions, resulting in high hardness with better ductility in most cases than equivalently hardened armour of other nations, and capable of being produced in rolled or cast. This is important especially because the T-34 had a mostly cast turret at the point of his quote. German cast armour was not good; where their rolled product was consistently superior to western allied plate, their cast was soft yet brittle and flaky, so bad that it was inferior even to the badly flawed American cast steel. Russian cast armour, on the other hand, seems to have been without equal amongst cast steels, despite uneven Russian quality control. Meanwhile, Russian RHA would have been likewise unsurpassed, had they been able to ensure even production quality. The massive expansion of production lines made that impossible, as they would have been for any other nation undergoing setting up new production lines on that scale relative to existing lines. Indeed, heavy flaws in American armour attest to that very same problem. But the quote, while it points to problems the Germans were having, doesn't prove bad armour. It proves good Russian armour.

  7. When the Germans had Moly, they used a triple dip oil quench where varying the temperatures of the bath 'adjusted' the temper. When they switched to Vanadium this process was no longer enough because Vanadium has a flash over point beyond which it sets and further quenchings have limited effect.

    You would then take a sample chunk from the metal, gauge it's hardness and apply a further flame treatment ('Einsatzhärtung' = Case Hardening) which would do two things:

    First it would create a surface tension in the metal that was greater than that of the core. If the core was already high hardness the molecular covalency difference between the two would make bonding between the two all but impossible so now you have a 'floater' of ultradense surface metal atop a pool of inner steel already at (variable, Vanadium is very ununiform in response to normal thermal treatments) enormous crystaline tension. Place your two hands together as tight as you can and interlace just one or two fingers as you try to rub them together. Consider the fingers to be crystalline boundaries between the two metals where the two form a common bond. The sheer effect of striking that metal with not break off the fingers but /drag them/ so that surface cracks are spread throughout the chemical boundary.

    The other problem with this kind of treatment is carburisation which GREATLY increases the potential for embrittlement inclusions in the steel itself.

    You use case hardening to create things like gears where the stresses are high but uniform in given loading condition. Properly done, they will last FOREVER because they are are that hard.

    As others have said however hard atop hard, as a function of internal stressses in the metal from the foundry at the molecular and ultimately, nano-levels (atoms at different energy states do not cross orbital boundaries to share electrons) means that sudden ramp ups in unexpected impact stress creates both pro-caliber cracks around the penetration and in-depth migration of those cracks into the backing plate. This effectively thins the armor at the same time it compromises it's integrity and allows the rear facing to spall off.

    The Germans were well aware of this problem by 1943 and convinced Hitler that they would need to start thinking of smaller vehicles with more extreme sloping and a return to 1941 levels of 30-40mm sides and 50-60mm fronts. They had simply lost too many tanks and expected rates of destruction to increase as the Einheits standardization program began on the road to 'common component' vehicles in the E-5/10/25 classes of turtle TDs.

    Hitler, having seen the Maus and understanding that that was simply not an option anymore said: 'Okay but that NEW ARMOR had better be ready before you do this!'

    1. That new armor was the mythical 'Brimstone' and probably what the German should have gone with from the beginning. As the earliest form of NERA and similar to the applique armor later seen on the Kanonepanzer and Raketenpanzer (Jaguar) variants. It may well also have something to do with what the Soviets would later call 'Brow' armor, tested on some T-55 models.

      Namely, with brickbats from bombed out cites all around, you grind it up, pour the mix into a mild steel box with a honeycomb matris of welded thin plates and pass the whole mess through a kiln as much as a forge. Rehardening the masonry to something near concrete and setting it into tension with mild steel matrix. Hit the steel face with small arms and ATRs and they go right through but are so small that the aggregate inside traps and dissipates their energy. Hit it with APCBC and the aggregate blows back outwards through the hole like any untamped explosive while the steel matrix holds the rest in place for 1-2 more hits. Hit the box with APCR and the matrix itself compresses like a finely sprung matres with the concreate acting as the stiffener to retain functional resistence, differentially turning the round with the equivalent of cavitation stress so that it breaks up or is at sub optimal normalization when it hits the inner face of the armor box and tries to continue through to the real hull.

    2. If you've ever seen shots of Panthers and some Tigers with their flat side armor and the strange attachments that look like the skirt mounts for an E-100, these are Brimstone mounts.

      And like all composite/applique systems, they are not intended to save the tank perse so much as do a Secret Service Presidential block job on an inbound round while being taken out. And then be replaced immediately after the battle. Where tank fights in the much closer quarters of Eastern Europes temperate rain forests were going to be the norm, range based overmatch and auto-flanking kills would be the norm which meant that engagements would be very fast (decided in the first 10-20 seconds, not even a DPM based system, no 'ramjaeger' combats). And so anything you could due to turn a slope sided vehicle into a slab sided vehicle without disrupting the terminal armor defense and without having to send tanks back to depot for time intensive hull repairs would be a 'good thing' in that ops tempos would be (and were) _very high_.

      I would add one other thing. The E-series is the S-103. The GT-103 is the S-Tanks engine. Why wouldn't the 'mythical Krupp steel' with it's extraordinary (off the scale) Brinnell numbers be the payoff lineage for the Armox Armamax line of very high density nano-metallic armors used by almost all makers today?

      That is how good Krupp steel was. It's just that it's properties were not understood relative to the necessary ballistic qualities of effective, modern, composite 'backpacks' of layered armor which must both capture the initial tip-impact energy and contain/scatter it's HEAT or SLRP based chemical or kinetic followons. Krupp was IG Farben and IG Farben was so far ahead of everyone else in terms of chemical process experiments that a lot of what we stole from the Germans is secret, even today (they tried to sue the U.S. government for 'stolen processes' in the 1950s and actually won a couple cases before it was all shut down in the interest of the common good).

      I think it would be _very_ instructive to this debate to have a map of which factories, smelter complexes and R&D labs were in each zone and how much of what they were working on showed up as 'home grown' in later indigenous products.

      The obvious example being Manfred Von Ardenne who, along with Fritz Houtermanns, completed critical density calculations for _fusion weapons_ and were deep into the chemical and mechanical design processes for such things a extracted Lithium from feldspar and sea brine for booster and levitated pits for multi-staging. When the Russians came knock-knocking on their Berlin suburb door and _very gently_ levitated the entire laboratory to Deepest, Darkest, Russia where they 'invented' the materials sciences behind the Russian bomb to the extent that they laughed at our 'exploding meat packing plant' when we brought thm as observers to Ivy Mike. Von Ardenne came home to East Germany with TWO Stalin Prizes from that little adventure and promptly started the primary state technical R&D corporation which kept East Germany from falling back to medieval levels throughout the Cold War.

      Much that is assumed is not true about the Germans. And the first among these is that they did not comprehend or comprehended and refused to devise answers for the problems they knew they were facing because 'Hitler was a madman and it was a readily catchable form of insanity'.