The KV-1 was criticized by its crews for its poor mobility and the lack of a larger caliber gun than the T-34 medium tank. It … See more

The IS-2 tank first saw combat in early 1944, equipping elite Guards Heavy Tank Regiments of the Red Army. A regiment had 21 IS-2 tanks in four companies of five tanks each and one being used by the regimental … See more

KV-85 (Object 239) A stopgap model built from a modified KV-1S hull mated to an Object 237(IS-1)'s turret and armed with the 85 mm D-5T. An alternate prototype designated KV-85G (for Grabin, who designed … See more

There are several surviving IS-1 and IS-2 tanks, with examples found at the following:
IS-2
• Os. Górali [standing tank], Kraków, Poland
• Polish Army Museum, Warsaw, Poland… See more

• Higgins, David (2011). Kingtiger vs. IS-2: Operation Solstice 1945. Duel. Osprey Publishing. ISBN 978-1-84908-405-5.
• Jentz, Thomas (1995). Germany's Panther Tank: The Quest for Combat Supremacy. Atglen, PA: … See more