Development History of the ISU-152
After recovering from Operation Barbarossa in 1941, the Soviet Army realised it required a heavy assault weapon to remove enemy positions at range, especially in urban environments. Thus, the ISU-152 was born.
The ISU-152 was the successor to the SU-152, as the KV-1 chassis that the SU used was at the end of its production cycle. This made the modernisation of the tank a necessity, and as such, the IS Heavy Tank chassis was chosen to be the base of the new ISU-152. On 25 May 1943, Factory 100’s administration ordered the modernisation of the SU-152, which included several improvements.
Under the designation IS-152, it was tested from September 1943 until November 1943, when several critical errors were found in development, so it was sent for further improvement. On November 6th of the same year, the tank adopted its designation ISU-152, with production beginning in December 1943.
About the BL-10 Gun
The BL-10 gun was originally mounted on the ISU-152-2 towards the end of World War II, and is an improvement on the BL-8 gun– it is able to penetrate 205mm of armor from 1km. Due to the war being won during testing as well as poor barrel integrity and horizontal guidance, the development of the gun soon ceased as there were no German vehicles that needed such a weapon.
Historical Tactics & Uses of the ISU-152 in World War II
The main operation of the ISU-152 was second-line support, usually behind IS tanks who had similar manoeuvrability. Due to the nature of its main gun, the ISU could also be used as a heavy self-propelled artillery.
During the Assault on Berlin, ISU-152s operated in pairs as heavy assault gun platforms, and were accompanied by several infantry squads to minimise the risks of Panzerfaust attack. These squads usually had a dedicated sharpshooter, several machine guns, and sometimes a flamethrower.
The tasks that the ISUs were given were to assault fortified positions in a direct role, as their armor was very effective at repelling German anti-tank fire. Their HE shells were also more than enough to destroy or immobilise the best armored vehicles that the German Army could throw at them–even the Tiger I and II, as well as the rare Jagdtiger and Ferdinand/Elephant.
The ISU-152 in Service
Aside from helping the Allies defeat Germany in World War II, the ISU-152 remained in service with the Soviet military until the 1970s, and went on to serve in many armies and conflicts around the world.
Countries like Poland, Czechoslovakia, Yugoslavia, Romania, China, North Korea, Egypt, Iraq, and even Finland (who captured one during the Continuation War) all leveraged the tremendous power of the ISU-152, either in conflict, or as sovereign protection.
The Soviets again called on the ISU-152 in 1986 during the Chernobyl Nuclear disaster, in what was described as ‘unconventional action’.