ARMOR SKIRTING ON GERMAN TANKS
Tactical and Technical Trends, No. 40, December 16th 1943
From both Allied and German sources, reports have come in of additional armored skirting applied to the sides of German tanks and self-moving guns to protect the tracks, bogies and turret. Photographs show such plating on the PzKw 3 and 4, where the plates are hung from a bar resembling a hand-rail running above the upper track guard and from rather light brackets extending outward about 18 inches from the turret.
Panzer IV Ausf.H in the Army Group South sector August 1943.
What appeared to be a 75-mm self-moving gun was partially protected by similar side plates over the bogies. This armor is reported to be light -- 4 to 6 millimeters (.16 to .24 in) -- and is said to give protection against hollow-charge shells, 7.92-mm tungsten carbide core AT ammunition, and 20-mm tungsten carbide core ammunition. This armor might cause a high-velocity AP shot or shell to deflect and strike the main armor sideways or at an angle, but covering the bogies or Christie wheels would make the identification of a tank more difficult, except at short ranges.
A further U.S. military report on the German use of armor-skirting on tanks was published in Tactical and Technical Trends, No. 42, January 13, 1944.