Comparing: IS vs. IS-6 vs. IS-2

The IS-1 (IS-85) heavy tank was a thorough modernization of the KV-1. The tank featured the 85-mm D-5T gun. The IS-1 entered mass production in October 1943, but work was discontinued at the beginning of 1944, as the IS-2 (IS-122) tank entered mass production in December 1943. A total of 107 vehicles were manufactured.

Plans for this vehicle were drawn up in the construction bureau of the Chelyabinsk Kirov plant from December 1943 to the summer of 1944. Further development and the construction of the first prototype took place at the Uralmash plant. However, the vehicle had no advantages over the other heavy tank designs under consideration, and its armor was seen as inferior to the IS-4 (Object 701), so the IS-6 was not selected for production.

Built in 1944, the IS-2 (IS-122) heavy tank was a modification of the IS-1. It featured a simple cast glacis plate. Elite Soviet Guards heavy tank regiments used the IS-2 extensively in the assaults on the fortress cities of Budapest, Breslau, and Berlin. These vehicles featured thick white stripes for quick identification by other Soviet tank crews. This vehicle, a tank of the 7th Guards Independent Heavy Tank Brigade, was made famous in a photo taken in front of the iconic Brandenburg Gate in the heart of Berlin.