The last recorded action of the T-35 took place during the First Battle of Kharkov, where four tanks undergoing repairs at their home factory (renamed Factory No. 183) were made roadworthy, re-armed and hastily pressed into service in the defense of the city. At least one captured T-35 was shipped to Germany for evaluation at the Kummersdorf military proving ground. This tank (serial number 715-62) was meticulously inspected and showed widely divergent armor thickness values used in its construction, likely the result of poor quality control of armor plate supplied by the steel mills. In April 1945, this tank, now stripped of most of its armament and immobile, was assigned to Panzer Brigade 150 and towed into the town of Zossen where it was used as a fixed fortification and barricade.