SS: This is a translation of Tuccy's post on Schürzen. For those who don't know him, Tuccy is a Czech community organizer and a tank buff - in fact, he's one of the most knowledgeable people on any WoT forums, when it comes to real life tanks and history - compared to him, I'm a schoolkid. So when he writes something, it's really worth reading. This time, he wrote about the Schürzen and the widespread myth that they were supposed to protect vehicles against HEAT projectiles. It's basically the same thing that H.Doyle said in Operation Think Tank.
Spaced armor in the form of thin metal plates, so called Schürzen ("skirts") appeared en masse around 1943 and it was immediately misunderstood. Due to the fact it came by the time the Allies discarded their AT rifles and started using hand-held HEAT warhead weapons (PIAT, Bazooka), the western authors have the tendency (supported by copying each other's texts) to state that this was to protect the tanks from HEAT warheads.
Luckily for us, we have our well-informed original sources, that give us proper insight - in form of German documents (for example in Spielberger's books on Panzer III, Panzer IV and Panther). During the Schürzen development, following threats were considered:
- 14,5mm shots from Soviet PTRS and PTRD anti-tank rifles
- HE shells from field guns
Regarding the AT rifles:
June 1941 caught the Red Army off-guard and without proper anti-tank armament. One of the weapons designed to rectify this situations were simple, mass-produced 14,5mm rifles. Compared to their German counterparts, their caliber was bigger (SS: Germans used 7,92mm special long cartridges) and compared to their western allied counterparts, they were often lighter and balistically more powerful - essentially, it was the peak of AT rifle development, beause - unlike early rocked or recoilless guns with HEAT warheads, they were reliable and (what was even more important) they didn't require new industrial capacities.
Their penetration ability (at least 35-40mm at 100m) was fully sufficient to penetrate Panzer III, IV and Panther side armor and proved to be a serious threat also to lightly-armored tank destroyers and self-propelled anti-tank guns. Furthermore, they were used en-masse, a Soviet batallion anti-tank company consisted usually of one platoon with 45mm guns and two or three platoons with 8 AT rifles each.
Regarding the HE shells:
Lack of arms and ammunition in June 1941 led to massive use of HE shells against tanks (in Fall 1941, there were only 10 76,2mm AP shells per barrel on average in the Red Army, they were also BR-350 and BR-350A shells of dubious quality). HE shells fired from field guns (75-76mm) could eventually penetrate up to 30mm of armor and even if they didn't penetrate it, they at least caused spalling.
Since it would be too expensive and complicated to rebuild the tanks, that were destined to be replaced soon anyway (Panzer III, IV), the German engineers accepted the relatively simple Schürzen solution despite the fact that it brought increased weight with it. What was even more annoying that the relatively thin vertical side armor strip of the Panther was also vulnerable to AT rifle fire. First reaction was to initiate the Panther II development - its thicker side armor was designed to counter specifically this threat, but after the success of the Schürzen, the Panther was "saved" by having the skirts mounted on it.