Photo of SU-152
The SU-152 was a dual purpose gun, mounting a 152mm L/32 howitzer on a KV-I chassis. Its tank killing role was outstanding, and it would later be known as Zvierboy (Animal Killer) as it could knock out Tigers, Panthers, but also the giant Elefants. Prototypes of the KW-14 (later SU-152) on modified KW-1s chassis were completed in a record 25 days, and on February 7th of 1943 barely a month after the Russians captured their first PzKpfw. VI Tiger I, and the first twelwe of the SU-152s were rushed to Kursk in July 1943, and an additional nine would arrive as reinforcements. SU-152's (as Jagdtigers) carried an explosive charge to destroy the cannon and the engine in case of capture danger. When production of the KV-I ceased in 1943, it was decided to use IS-I chassis as the basis for the new heavy assault gun mounting the 152mm ML-20 howitzer. This gun had the advantage of using the same carriage and recuperator system as the 122mm A-19 gun, so it was possible to produce both an ISU-122 and an ISU-152, simply by changing barrels and reorganizing internal ammo. ISU-152 tanks with the 152.4mm BL-8 howitzer were officially named ISU-152-1, and later ISU-152 tanks with a 152.4mm BL-10 howitzer were named ISU-152-2. For both models, the crew compartments were enlarged, being higher and less sloped sides, while the hatches of the ISU-122 mounted the M1944 L/43 A-19 gun with a wedge breech block and fired a 55lb shell to a range of 13km. A total of almost 2.500 had been produced, the next series of were fitted with the 122mm D-25S L/43 tank gun, with a large muzzle break which had better armour penetration. The 152mm howitzer fired an HE shell weighing 96lbs to a range of 8,9km and, despite its slow rate of fire, its 107lb AP round could start to kill enemy tanks at asstounding ranges. ISU-152s played an important part in The Battle for Berlin since its powerful armament enabled it to destroy German strongholds holding up the Russian advance. Additional armament consisted of a 12.7mm DShK machine gun fitted over a roof hatch, and the vehicle often had to be supported by infantry so that the enemy troops not were able to take them out with anti-tank weapons. The main drawback of the vehicle was the limited ammo carriage of just 20 shells, so extra shells were often stowed on the rear deck, as were extra fuel tanks to increase the operational range. The ISU-152 remained in production until well after the war, and the last version of the vehicle was the post-war ISU-130 mounting a 130mm gun.
ISU-152 in Lodz, January 1945.