History
The Red Army entered WWII with most of its heavy artillery drawn by horses, making its movement slow and vulnerable to attack. The KV-2 assault gun was built to address the need for mobile artillery, but it was unsatisfactory as a fighting vehicle, mainly because of its large and overweight turret. It was therefore decided to replace the KV-2 with a new vehicle based on the KV-1S chassis. But instead of a turret, the 152mm ML-20S gun-howitzer would be mounted in a low-profile casemate. Several designs were put forward, but the KV-14 showed most promise and was further developed into the SU-152 by February, 1943. This self-propelled gun weighed 45.5 tons and had armor up to 75mm thick; powered by a 600bhp V-2k diesel engine, it had a top speed of 43km/h. It was built at the Chelyabinskiy Kirovsky factory until replaced in production by the ISU-152 in December, 1943.