The KV heavy tank had been designed and used as heavy break-through tank. To a tank of the task, the shortcomings of its L-11 main gun, that will be negative at coping with enemies' bunkers and fortifications, might be deadly! Therefore a heavy tank carrying a much bigger gun to higher work was made alongside the 76.2 mm weapon tanks. The initial with this type makes use of a fresh big high turret of 7 sides that mounting the 152mm M-10 howitzer. This variation, which had numerous information differences towards the later standard kind was often dubbed KV 'Big Turret' or KV-2 Model 1939. As such a huge turret on usual KV hull turned out to be very un-maneuverable it quickly attained a funny nickname of "mobile phone washroom"!
