KV-1 with 132mm BM-8 Katyusha rocket launchers was developed in May 1942 by tank factory No. 100. That rocket system had name KRAST-1 (short rocket artillery system for tanks-1) – four armored boxes for two rocket launchers each were installed on the sides of KV – this is visible on the side photo above: two KRAST-1 were located on each side near the turret, another two – near engine compartment. So the tank was armed with 8x132mm rockets in addition to its main armament (driver had electric fuze for KRAST-1).
The tests were very successful (Research Firing Ground of Small-arms Weapon at Chebakul, August-November 1942), KRAST-1 was a powerful, effective and cheap weapon, it was possible to install it easily by army workshops on every serial KV and T-34. But there was no serial production of such system.
The driver of the tank had addition control panel with electric fuse [it was possible to fire single rocket as well as 2-8 rockets salvo fire even on the move, effective range of fire was 600-800 m and special angle indicator for determination of tank hull elevation. 3 crew members (from 5 of KV tank) were responsible for KRAST loading – it took 8 min.
The accuracy was quite good despite the fact that KRAST had shorter rocket launcher (1200, 1250, 2000 and 2400 mm launchers were tested) in comparison with standard BM-13 (5000 mm). The main disadvantages of the system were need in steering of the whole tank for laying and relatively short range of fire because of low elevation of rocket launchers, also rear rockets couldn’t be fired during turret rotation.