October
24, 2005
As Western visitors are unaware of the details of the KV's usage in the Winter War, I decided to create a separate article, based on the materials of [1].
Experimental KV, SMK and T-100 tanks were taken off the tests and thrown into battle. They formed a Heavy Tanks Company, included in the 91st Tank Battalion/20th Heavy Tank Brigade. Company Commander - Captain I. Kolotuskin. For the first time the company took part in combat on December 18 th 1939 supporting the attacks of the Soviet infantry in the Finnish Khotinnen Fortified Region. The first attack was performed after a preparatory bombardment together with the other tanks of the 20th Tank Brigade.
From memoirs of A.I. Yestratov: "...passed through the small forest and we saw a large glade which had become a battlefield. We could see burning tanks to our left and right. T-28’s going in advance burst into flames and preventing us moving forward. We are afraid of leaving the road because of minefields. Ahead we can see a tank ditch, obstacles and wire entanglements. We made an attempt to approach a burning T-28 and push it away from the road. The T-28's crew had left it via the escape hatch, but didn't turn off the shafting and our attempts failed. We got the order to leave the road and move along the tank ditch. Our tank was taking hits from the right side. Blow by blow they shook the tank but we are still moving. No enemy observed and so we search for hidden pillboxes....".
In this fight the KV got 9 hits from 37mm shells, one of which punctured its gun. The new gun was received on December 19 and installed by the crew. This tank was located in the frontline until January 02, 1940, but didn't take part in combat.
Experiencing this, Soviet Command ordered a new tank to be designed equipped with the heavy 152mm howitzer for the destroying of field fortifications. Such a tank, later called the KV-2 appeared on February 10th. It was an M-10 howitzer mounted on the hull of the first KV tank.
The first KV U-0 and KV U-1 tanks equipped with MT-1 devices (152mm gun in a large turret) were sent to Karelian Isthmus on February 17th. On February 22nd, KV U-2 tank equipped with the turret from the U-0 experimental tank (76mm gun) was sent to the frontline.
The last KV U-3 tank (with MT-1 device) was sent to the frontline on February 29th. Tank KV U-4 (with MT-1) was ready on March 13th, but it was too late to send it to the frontline.
All operable KVs together with experimental T-100 tank formed a separate Heavy Tank Company under Capt. I. Kolotushkin’s command. It was subordinated to the 13th Light Tank Brigade and 20th Heavy Tank Brigade. The Soviet Command couldn't test them on the pillboxes as the main Finnish defensive line had been broken through at that time. It was found that the first time Finns tried to hit the KV tanks that they were invulnerable to their fire. In combat KV tanks destroyed according to the crew's reports - 14 anti-tank guns and 11 wooden pillboxes.
Most of the damage inflicted on the KV’s were due to anti-tank mines. E.g. KV U-0 tank lost 8 tracks and 2 supporting rollers, U-1 - 11 tracks, U-2 - 3 tracks, U-3 - supporting roller. KV U-0 caught 14 hits, U-1 - no hits, U-2 - 1 hit, U-3 - 8 hits. All the hits had 10-40mm depth. No consequences were observed. The bad cross country activity in the snow of the KV tanks was also noted. 
