Brief Operational History

The KV (Kliment Voroshilov) tank series had its beginnings in 1938.  It was to give the Red Army a heavy tank with shell-safe armor, something that both the T-28 and T-35 had failed to do.  Originally  designers like L. E. Lytshev sought a heavy tank with multiple turrets, but S. J. Kotlin decided that a single turret mounting a high performance gun and heavy armor would be a better approach.  To make things more complicated, Joseph Stalin, took an interest in the selection process for the new heavy tank.  Many designs were proposed, but of these only three would be selected for test production.  

The first was a twin turreted design called the T-100 'Sotka'.  The second concept tank looked almost identical to the T-100, but was called the SMK.  These two tanks weighed  56 and 45 tons respectively.  Their prototypes saw action in the Russo-Finn war on the Karelian front, but had no real impact on the war.

The single turreted heavy tank design by S. J. Kotlin also saw action during the Winter War.  Two examples had been manufactured in September 1939 at his design bureau under a program headed by N. L. Duchov.  It was noted for its very heavy armor, which had been made possible by the fact that it had only one turret armed with a 76.2mm cannon.  Its performance was so highly regarded that it was recommended for full production on 19 December 1939.  Series production of the new tank (designated the Kliment Voroshilov) would begin in the Summer of the following year.

When the German army invaded the Soviet Union in 1941, the KV-1 proved to be one of the most feared tanks in the Red Army arsenal.  German anti-tank weapons and armor were poorly matched against the KV-1.  Only the powerful 88mm cannon could be counted on to reliably destroy these armored monsters.

To make matters worse for the Wehrmacht a new version of the KV-1 came into service shortly after the invasion.  It was designated KV-1b and was equipped with four tons of bolt-on armor plates that increased hull protection by 5mm on the hull and 10mm on the turret.  While this improved the armor of the tank, it slowed the tank to a maximum speed of only 29 kph.

The combat experience of 1941 showed that the tank was still quite heavy and not very maneuverable.  It also showed that while the extra armor gave it added survivability, its unreliable powerplant could cause the tank to break down either in route to a battle or even during one.  Soldiers who operated early models of the KV complained that they had difficulty changing gears because of clutch and transmission problems.

Production of the KV-1 series ended in 1942 when the armament problem was solved by giving the tank an 85mm main gun.  This version was known as the KV-85 and it replaced all earlier versions of the KV-1 series.  Around 4,000 tanks of the KV-1 series had been produced between 1940 and 1943.  They would see service until the end of the war.

Tactical Use and Limitations

Like the T-35 before it, the KV-1 heavy tank was designed as a 'penetration tank' that would be used to spearhead attacks through enemy lines as well as support light and medium tanks in battle.  Its heavy 'shell safe' armor made it almost invulnerable to anti-tank guns 76mm or smaller.  Its powerful main gun was also another advantage, but one that diminished as the war progressed.

The KV-1 suffered from a number of serious disadvantages as well.  Its slow speed and great weight made it difficult to utilize in combat situations.  It could only cross obstacles with difficulty and  would even cause damage to light bridges as it crossed over them.   Its automotive unreliability was another problem, for even the best tank is useless if it cannot maneuver on the battlefield.  The early engines had a service life averaging 100 hours.

Deployment Chronology

When the KV-1 was introduced in 1940, it gave the Red Army a true heavy tank that was almost unstoppable.  Over time combat experience showed that the tank would have to be improved.  Here you can see what vehicles the KV-1 replaced and tank eventually replaced it.  You will be able to find more about each vehicle if we have them on our site by clicking on the links below.

Sources Cited

Here are some of the most informative sources that we have used in compiling this information for you.  We hope you can find them as useful as we have.

• Russian Tanks and Armored Vehicles 1917-1945, by Wolfgang Fleischer, published by Schiffer Publishing Ltd., Atglen, PA, 1999

• The Encyclopedia of Weapons of World War II, edited by Chris Bishop, published by Barnes and Noble Inc., 1998