Comparing: IS-5 (Object 730) vs. KV-5

The development of the vehicle was started in 1949 by the Design Bureau of the Chelyabinsk Kirov Plant under the supervision of Joseph Kotin. In 1950 a preproduction batch of 10 vehicles was launched. After the vehicle underwent all trials and received upgrades, it was adopted for service in 1953 under the designation IS-8.

Development began in June 1941 at the Leningrad Kirov Plant and was completed by August, but plans were interrupted due to the complicated situation on the front. The KV-5 was to utilize some components of the KV-1. A new turret was designed, incorporating the 107-mm ZIS-6 gun. Two roadwheels and a single support roller were to be added on each side. A new 1,200 h.p. diesel engine was being developed for the vehicle, however it was not completed in time and was replaced with two V-2K engines.