The 47.3-tonne ISU-152 was a heavy vehicle that served in WWII in the role of a self-propelled gun, assault gun and tank destroyer. Originally based on the KV-1 chassis, it was adapted to the IS tank chassis and duly entered production in December 1943. It operated with a crew of five, and some 3,242 vehicles were built up till 1947. On the ISU-152-2 (also known as Object 247), the original 152.4mm ML-20S gun was replaced by a BL-10 high-powered L48.5 gun in a prototype that dated from August 1944. This 7.393m-long weapon had an 18,000m range. Although the actual ISU-152-2 type didn’t enter service with this gun, later versions of the ISU-152 remained in service right up till the 1970s.