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  • Originally posted by Nick the Noodle View Post
    None of the 76.2mm rounds are said to have penetrated. It was the overhardening that directly caused the spalling, which lacerated the turret crew. One wonders why such a report would be made up?
    For a start, I would like to see this "report".

    Comment


    • Dmitriy Loza, a Hero of the Soviet Union, commanding a tank brigade in the war, in his "Fighting For the Soviet Motherland: Recollections from the Eastern Front" (in English) spends three pages discussing the spalling issue.

      From the end of 1941 and throughout almost the entire subsequent twelve months, T-34 tanks were "involuntarily subjected" to the spalling of the armor of their own tanks. He notes the losing of a number of mineral-rich regions to the Germans in the initial period of the war resulted in the Soviets' plants that manufactured the armor for their tanks had received insufficient quantities of some of the smelted metals required to ensure the necessary toughness of armor. Hospital patient tankers recited a tankers' ditty "My tank's armor showed me no mercy. It wounded me with pieces of "Steel rain".

      The deficiency was finally eliminated in early 1943.
      Last edited by R.N. Armstrong; 16 Sep 20, 06:05.
      Leadership is the ability to rise above conventional wisdom.

      Comment


      • Originally posted by G David Bock View Post

        Yet still just one out of scores to hundreds of others not detected nor attacked, until war's end.
        Well, there are more than one; I know of a couple more that were detected and examined with a view to attacking them.

        But in general you are right; the Allies, by and large, did not attack these installations. They were hard to damage, but the Allies simply did not need to do that.

        By the spring of 1944, the combined Western air forces could and did reduce the enemy rail network to a shambles. Dispersion of production is a great defense, if you can then put the parts together. If you cannot move a train for 20 kms without running into a cratered station or junction, a collapsed bridge, or some other bombed out obstacle, then dispersal is no remedy. By means of the (anti-)transportation campaign, the Western Allies weren't just hindering, and then reducing to little more than nothing, the movements of German troops and supplies; they were doing the same to their industrial system.
        Michele

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        • Originally posted by R.N. Armstrong View Post
          The deficiency was finally eliminated in early 1943.
          Spalling was a normal thing for all armor, not something intrinsic to T-34 and IS. High-hardness steel was more prone to spalling though as well as welded seams which are known to be of rather inferior quality on Soviet tanks. In any case, such evidence doesn't say a lot without indications of where the tank was hit, by what projectile, at what angle with what velocity etc. In Soviet military the resistance of armor was quantified using the onset of rupture of the inner side of the armor plate as a criterion of resistance. Results of trial of IS armor resistance to projectiles of German guns are known, including diagrams, photos etc. Yet apparently nobody have seen results of alleged trials of resistance of IS armor to ZIS-3 shells but one particular Russian author from 1990s. Which makes his claims a little suspicious.
          First combat employment of IS tanks doesn't support the idea that crews tended to suffer some disproportional losses due to spalling while the tanks remained intact. Quite the contrary tanks were knocked out mostly by through penetrations, of 20 crewmen 5 were killed, 15 remained intact and bailed out (not such a bad ratio). Maybe later engagements were different, but I don't have such a detailed account on them.

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          • Originally posted by Artyom_A View Post
            Spalling was a normal thing for all armor, not something intrinsic to T-34 and IS. High-hardness steel was more prone to spalling though as well as welded seams which are known to be of rather inferior quality on Soviet tanks. In any case, such evidence doesn't say a lot without indications of where the tank was hit, by what projectile, at what angle with what velocity etc. In Soviet military the resistance of armor was quantified using the onset of rupture of the inner side of the armor plate as a criterion of resistance. Results of trial of IS armor resistance to projectiles of German guns are known, including diagrams, photos etc. Yet apparently nobody have seen results of alleged trials of resistance of IS armor to ZIS-3 shells but one particular Russian author from 1990s. Which makes his claims a little suspicious.
            First combat employment of IS tanks doesn't support the idea that crews tended to suffer some disproportional losses due to spalling while the tanks remained intact. Quite the contrary tanks were knocked out mostly by through penetrations, of 20 crewmen 5 were killed, 15 remained intact and bailed out (not such a bad ratio). Maybe later engagements were different, but I don't have such a detailed account on them.
            Loza goes on to write, "I will openly admit that when our 233rd Tank Bde of 5th Mech Corps first received Sherman tanks in the last months of 1943, we combat veterans, in studying their tactical-technical characteristics, recalled the possibility of armor spalling in the fighting compartment if enemy armor-piercing rounds were to strike it. We thought the M4A2 might be afflicted with the same "illness", though its armor was somewhat thicker than that of the T-34 (100 versus 90 mm)."

            "Our concerns were put to rest in the January 1944 battles on the flat fields of right-bank Ukraine, however, The Shermans took more than a few direct hits on the turret and did not manifest the infirmity that had plagued the early T-34s. Enemy rounds failed to penetrate their armor, and not one bit of spray erupted inside the fighting compartments. Instead, at the places where the enemy antitank solid-shot rounds had struck the exterior surfaces of the tanks, there were marks--spots of various diameter and depth, which were frequently accompanied by hanging "icicles" of melted turret steel. An unquestionable sign of the high tensile strength of the armor, these marks were dubbed "Hitler's kisses" by our tanker comedians."
            Leadership is the ability to rise above conventional wisdom.

            Comment


            • So, a thicker armor is said to be more resistant to projectiles. Sounds like truism. However, T-34 of 1943 didn't have 90mm-thick armor, neither Sherman had 100mm IIRC. That confirms that such evidences are better to be viewed with sound scepticism, even more so they were subjected to survivorship bias. The objective characteristic describing armor resistance are usually results obtained at the proving ground with a known caliber and type of projectile, known impact angle and velocity, known point of impact etc. The resistance of IS armor to German guns was studied this way, see for example the diagrams here
              http://zhurnalko.net/=weapon/tankoma...anki-is--num58
              and results are more or less consistent with penetration tables. Yet nobody have seen any results of IS trials under fire of ZIS-3 gun except a single Russian author who didn't provide any reference to his source. If somebody shows some data from these alleged trials (similar to the diagram posted above, for example) then I would start to believe that they were real. Right now I'm prone to think that it's just a urban legend.
              Last edited by Artyom_A; 17 Sep 20, 04:01.

              Comment


              • Regarding spalling: again, it was a normal phenomenon. You shouldn't see it like happening at every impact irrespective of the type and caliber of projectile and impact velocity. There was a certain threshold of impact velocity when the inner side of the armor started to rupture and large-scale spalling occurred. This penetration diagram for the IS-2 tanks relates to this threshold (PTP limit):
                http://zhurnalko.net/images/9/0/909b...a/page0058.jpg
                Below this limit small-scale fracturing of the armor could happen though. There were also welding seams which tended to broke down more easily from close impact than normal armor. I suspect, there were also other parameters like the number, size and velocity of the splinters, but I don't remember somebody analyzing them.
                Last edited by Artyom_A; 17 Sep 20, 07:13.

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                • Dmititriy Loza served as an instructor at the Frunze Academy after the war. Both his books, "Commanding the Red Army's Sherman Tanks" and "Fighting for the Soviet Motherland" are credible and insightful recollections from the Eastern Front. He makes this observation, "From the moment they became aware of the situation, Smersh personnel busied themselves in the investigation. Coming rapidly to the conclusion that the spalling was evidence of sabotage in the factory production line, they filled their counterintelligence communication channels with messages to higher headquarters."

                  And now it is "an urban legend"?

                  I like the credible and insightful veteran's account who was in the combat action, not seven decades later.
                  Last edited by R.N. Armstrong; 17 Sep 20, 06:14.
                  Leadership is the ability to rise above conventional wisdom.

                  Comment


                  • Spalling is not a legend, it is a known phenomenon that happens with every armor more or less. What I call a legend is an alleged trial where IS-2 turret armor was ruptured by ZIS-3 ammo (while it shouldn't be according to penetration tables). Again, the only source for this trial is Baryatinskiy/Svirin, there is no reference, more recent authors like Zheltov, Pavlov, Pasholok etc didn't write a word about this trial, although they provide a detailed description of trials of IS armor resistance to German guns, e.g. see:
                    https://warspot.ru/12831-malaya-mode...bolshogo-tanka
                    http://zhurnalko.net/=weapon/tankoma...ecial-tanki-is
                    That makes me a little skeptical.

                    Comment


                    • Originally posted by Artyom_A View Post
                      Spalling is not a legend, it is a known phenomenon that happens with every armor more or less. What I call a legend is an alleged trial where IS-2 turret armor was ruptured by ZIS-3 ammo (while it shouldn't be according to penetration tables). Again, the only source for this trial is Baryatinskiy/Svirin, there is no reference, more recent authors like Zheltov, Pavlov, Pasholok etc didn't write a word about this trial, although they provide a detailed description of trials of IS armor resistance to German guns, e.g. see:
                      https://warspot.ru/12831-malaya-mode...bolshogo-tanka
                      http://zhurnalko.net/=weapon/tankoma...ecial-tanki-is
                      That makes me a little skeptical.
                      I could see the occasional freak penetration due to poor quality casting and / or metallurgy. For example if you had a casting that had a void in it, or had crystalized with large crystal structure (there are a number of reasons that could happen) you could end up with armor that is very poor quality in a particular spot on the casting that when hit results in a penetration.

                      With castings, a good part of the spalling effect is incumbent on how rough the casting itself is. Even going over the surface of a casting with a grinder and smoothing it will reduce spalling significantly.

                      Comment


                      • Originally posted by Artyom_A View Post
                        For a start, I would like to see this "report".
                        The report was here: http://english.battlefield.ru/tanks/...s/19-js-2.html
                        Unfortunately the page is no longer available.
                        However from my post 4398838, I did quote exactly from that page:
                        In March 1944, firing tests were conducted with a 76.2 mm Gun ZiS-3 firing at an JS-2 tank from 500-600 metres. The tank's armour was penetrated from all sides of the tank. Whilst while most of the projectiles did not penetrate the armour completely, they created major splintering and fragmentation inside the turret. This explains the considerable losses of JS-85 and JS-122 tanks during the Winter-Spring of 1944.
                        How to Talk to a Climate Skeptic: http://grist.org/series/skeptics/
                        Global Warming & Climate Change Myths: https://www.skepticalscience.com/argument.php

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                        • image_85354.jpg
                          Losses of IS tank were nil in winter 44 and low in spring. They can also be compared with the losses suffered by the Tiger tanks.
                          There are no Nazis in Ukraine. Idiots

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                          • Originally posted by Nick the Noodle View Post
                            The report was here: http://english.battlefield.ru/tanks/...s/19-js-2.html
                            Unfortunately the page is no longer available.
                            However from my post 4398838, I did quote exactly from that page:
                            It's not a "report" actually. That's an English translation of Baryatinskiy brochure of 1998. Except that Baryatinkiy wrote that the tank was manufactured in March, not that the trials were made in March. Unfortunately, there is no reference to a primary source here. Worth to repeat again, more recent publication in Russian (links provided above) have far more detailed description of IS armor trials. But not a single word about this ZIS-3 trial. How could it happen, what's your opinion?

                            Comment


                            • Originally posted by Emtos View Post
                              image_85354.jpg
                              Losses of IS tank were nil in winter 44 and low in spring. They can also be compared with the losses suffered by the Tiger tanks.
                              Where is the table from? Several IS-85 were lost irreparably in February 1944 so it's not 100% accurate.

                              Comment


                              • Originally posted by Emtos View Post
                                image_85354.jpg
                                Losses of IS tank were nil in winter 44 and low in spring. They can also be compared with the losses suffered by the Tiger tanks.
                                This table only shows losses, etc., of ISU 122, 152, and SU 152 if I'm reading it correctly.

                                Comment

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