ISU-152 - History

History

The ISU-152 marks its beginning on January 24, 1943. This was the moment of appearance of the first fighting vehicle of this family. It was designated Object 236 (Объект 236), using the same concept as the SU-152. The Object 236 was completed in Factory No. 100 in Chelyabinsk, and on the same day, January 24, underwent trials on the Chebarkulski artillery range, 107 km from Chelyabinsk. By February 7, 1943 the trials were over, passed with success. On February 14 the vehicle was adopted and put on production under the KV-14 (КВ-14) designation. In April 1943 was ordered KV-14 to be henceforth designated SU-152 (СУ-152). In time, the combat performance of SU-152, based on the KV-1S tank, made necessary the modernisation of the vehicle, using the new IS tank as a base. On May 25, 1943, shortly after deployment, the administration of Factory No. 100 ordered the beginning of the SU-152 modernization, which included an increase of the armour protection and other improvements. The development began in July 1943, under the supervision of Joseph Yakovlevich Kotin (the chief designer of Soviet heavy tanks) and G. N. Moskvin as the main designer, and in about a month the first modernized variant was ready. It was designated IS-152 (ИС-152). It underwent factory trials in September 1943, revealing a large number of different deficiencies, which sent it back for further improvement. In October 1943 a second (different) modernized variant was ready, designated Object 241 (Объект 241). It was an improvement over the IS-152. The factory trials began the same month, followed by state trials on the Gorohovetskom test range. On November 6, 1943, an order was issued for adoption of this variant, under the ISU-152 (ИСУ-152) designation, and in December its production began at the Chelyabinsk Kirovsk Plant, replacing the SU-152.