In the fall of 1941, the Russian high command request an mobile artillery vehicle. Under the guidance of engineers V. Sidorenko and N. Usenko, they designed in December 1941 the Object 229 and was the KV-1 Model 1942 armed with an 122 mm U-11 Tank Howitzer. The built of this vehicle took place until April 1942. After successful test, it was accepted as the KV-9. The weight of the tank was 47 tons and it had a crew of four men: two in the turret and two in the hull. The tank had the easily replaced cast turret from the KV-1. For protection of the tank against antitank guns, its frontal armor had an enormous for the time thickness of 135 mm. The armor thickness on the turret roof was 40 mm. The tank was equipped with a TMFD telescopic sight. The U-11 cannon had semi-fixed ammunition from the M-30 Howitzer, its vertical elevation angle was -4° +19,5°. The tank's basic load consisted of 48 rounds for the main gun and 2,646 cartridges for the three 7.62mm DT machine-guns.
