The prototype of the ISU-152 was introduced in Januari 1943 as Project 236. On a KV-1 tank base the Soviets placed a huge gun in response to the new German heavy and medium tanks like the Panther and the Tiger. When the production of the KV-1 stopped the Soviets turned to the IS-1 tank chassis as gun platform. The ISU-152 fabrication took place in Factory number 100 in Chelyabinsk, in west Siberia, behind the Ural mountains.
The gun was intended as a self-propelled Howitzer and started out as SU-152. After the switch to the IS-1 chassis, together with other upgrades like armor and modernization of the tank systems the name changed to ISU-152. The first prototypes showed lots of problems but after adjusting and fine tuning the new Self-propelled tank went into production. At first the ISU-152 lacked an machinegun for close defense, later during the war a 12,7 mm machinegun was added an IS-2 Russian Tank chassis were used.
The purpose for the ISU-152 Assault gun was to destroy fortified positions with its 152,4 mm howitzer. But is seemed it worked excellent as a heavy tank destroyer as well and sometimes supported an artillery bombardment. As assault gun is was most valued in urban settings with its powerful gun and strong armor. It could resist a punch with its 90 to 120 mm frontal armor but always worked together with Soviet infantry troops. Its low velocity high explosive shell, 40 to 50 kilograms depending on the type, took care of fortifications and obstructions and opened the way for the Soviet soldiers.
Tank Destroyer – The Beast Killer
Although not designed as Tank Destroyer it soon received the nickname Zveroboy or Beast Killer. It did not have a high rate of fire due to the cumbersome shells, 2 to 3 shots fired a minute. It was not as accurate as dedicated tank destroyers. Shells hardly penetrated the enemies armor. But a hit on an enemy tank took out the tracks and immobilizing it. Even without penetrating the armor the ISU-152 could blow the turret off a Tiger I tank. The brute force of the explosion shattered the inside of a enemy tank killing all crew members inside with a single blow.
The ISU-152 could molest the Panther, Tiger, Elefant, Nashorn and others from the German Armored Zoo, earning the him the name Beast killer.
The ISU-152 had a crew of 4 or 5. It weighed 47,3 tons, reached a top speed of 30 km/h on roads and 15 to 20 km/h off road. It used a V12 diesel engine with 520 Hp. It reached a distance of 120 km to 200 km on the internal fuel tanks (off and on road) and up to 320 km with external fuel tanks. It was built 4635 times until 1959. It was upgraded during and after the war, the 1945 version had a 320 mm armor around the gun area.
The ISU-152 on the photos was seen in the MM-Park museum in France and bears the white eagle used by the Polish forces.