Comparing: ISU-122S vs. AT 15A

A heavy assault gun, built on the basis of the IS tank, was effective against German heavy tanks as well as fortifications. The prototype was built at the Chelyabinsk Kirov Plant in April 1944. The vehicle entered service in August of that year, and a total of 675 vehicles were manufactured in 1944 and 1945.

Assault tank conceived for breakthrough attacks on enemy fortifications. The design project was ready on October 5, 1943. No prototypes were built. However, the project became the basis for the A39 Tortoise heavy assault tank.