KV Tank Series
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modified: Nov 10, 2012
The KV (Kliment Voroshilov) tank refers to a series of Soviet heavy tanks named after Kliment Voroshilov.

The Soviet Union was looking for a heavy tank to replace the T-35 which was unreliable and expensive. The SMK and T-100 prototypes were developed to fulfill the requirements which called for a multi-turreted tank. Kotin did not like the multi-turret idea, so he was given permission to develop a single-turreted version of the SMK designated KV.

The first KV prototype was built in August 1939. The KV was planned to mount the 76.2mm F-32 gun from the Grabin team at Zavod Nr. 92. However, it was not ready in time and a 76.2mm L-11 was used instead.

The KV, SMK, and T-100 prototypes were sent to NIIBT in September 1939 for display and trials. The KV outperformed both the SMK and T-100 in mobility. The tanks also took part in the Finnish War as part of the 20th Heavy Tank Brigade. The KV was accepted as the new heavy tank of the Red Army.

The commander of the Soviet 7th Army in Finland, K. Meretskov requested a heavy tank with a more powerful gun than the KV to destroy reinforced bunkers. This request initiated three projects. One was a T-100 modified with a 130mm B-13 naval gun. It was designated SU-100Y but did not enter mass production. The Kotin team experimented mounting a 152mm Br-2 gun or a 203mm B-4 howitzer on a KV tank. It was designated the SU-212 or Obiekt 212. However, it was also aborted.

A third attempt was mounting a 152mm howitzer in a large turret on a KV tank. At first, it was designated "large-turret KV" but later it was called the KV-2 heavy artillery tank. The original "small-turret KV" was designated the KV-1 heavy tank. By the end of 1940, the Kirovksiy Works has built 141 KV-1 and 102 KV-2 tanks.

KV-1 Model 1939 KV-1 Model 1940 KV-1 Model 1941 KV-1 Model 1942
Type (Role) Heavy Tank Heavy Tank Heavy Tank Heavy Tank
Origin Soviet Union Soviet Union Soviet Union Soviet Union
Years of production 1940
Weight (Metric tonnes) 43.5 43 45 47
Crew 5 5 5 5
Length, gun forwards (m) 6.8 6.68 6.75 6.80
Width (m) 3.3 3.32 3.32 3.32
Height (m) 2.7 2.71 2.71 2.71
Engine 600hp V-2K V12 diesel 600hp V-2 diesel 600hp V-2 diesel 600hp V-2 diesel
Operational range on road (km) 250 335 335 250
Road Speed forward (km/h) 35 35 35 28
Fuel capacity (l) 600 600 600 600
Armor (mm) 30-90 25-75 30-90 [show]
20-130 [show]
Primary Armament 76.2mm L-11 gun 76.2mm L-11 gun 76.2mm F-34 gun 76.2mm ZiS-5 gun
Secondary Armament 3x 7.62mm DT machine gun 2x 7.62mm DT machine gun 4x 7.62mm DT machine gun 4x 7.62mm DT machine gun


After the sucess of the KV tanks, the Kotin team proposed the KV-3, and the 100 ton KV-4 and 150-ton KV-5 superheavy tanks. The KV-4 and KV-5 did not pass the design stage. There were two versions of the KV-3. Obiekt 220 was a redesigned KV-1 with a longer hull, larger turret, a heavier 85mm gun, and more powerful engine. Obiekt 222 was a KV-1 with a F-32 gun. The third cewman, instead of the commander, became the loader and he was provided with his own cupola.

According to intelligence reports, the head of the GAU, Marshal I. Kulik asserted that the new Soviet 57mm anti-tank gun and 76.2mm tank gun were not effective against the heavily armored German tanks. As a result, he ordered the abandonment of the 57mm and 76.2mm gun production. Garbin's gun design team stopped development of the 85mm gun and instead focused on the new 107mm ZiS-6 gun for Obiekt 220.

Because of the war, the plan to field the KV-3 tank was abandoned. The 107mm gun, which Kulik insisted, was never completed. Instead, the prototype was armed with an 85mm naval gun when it was used to defend Leningrad.

When the Second World War began, there were several problems with the KV heavy tank. Early versions of the KV had clutch and transmission problems. The tank had to virtually stop to change gears. As a result, the planned road speed of 35km/hr could not be achieved. The KV-1 Model 1939 was armed with the L-11 gun. The KV-1 Model 1940 mounted the improved F-32 gun.

The KV turrets originally had 90mm frontal armor and 75mm side armor. Kulik ordered increasing the armor and 35mm applique armor was attached to the turret sides and some portions of the hull front and side. This variant was called KV-1E Model 1940 (KV-1 Model 1940 s ekranami: with applique). The last series of KV-1 Model 1940 tanks had a new welded turret with thicker armor.

The KV-2 had an effective 152mm howitzer. However, its primary role as a bunker penetrator was irrelevant at that time. When KV production facilities were re-established in Chelyabinsk, the KV-2 was dropped and all attention was turned to the KV-1.

The T-34 which was armed with F-34 was more powerful than the KV-1 which mounted an F-32 gun. As a result, the new KV-1 Model 1941 was armed with either the F-34 gun, or the ZiS-5, a redesign of the F-34 with better integration to the KV fire control system. Chelyabinsk was also given the task of simplifying the KV tank. A new cast turret, which was easily manufactured, replaced the welded turret. The road wheel design was also simplified and hull applique armor use was standardized.

KV-1E Model 1940 KV-1S Model 1942 KV-2 Model 1940 KV-2 Model 1941
Type (Role) Heavy Tank Heavy Tank Heavy Assault Tank Heavy Tank
Origin Soviet Union Soviet Union Soviet Union Soviet Union
Years of production Spring to summer of 1941 August 1942-April 1943 1940-1941
Weight (Metric tonnes) 47.5 42.5 52 52
Crew 5 5 6 6
Length, gun forwards (m) 6.8 6.80 7.0 6.80
Width (m) 3.3 3.25 3.25 3.32
Height (m) 2.7 2.64 3.3 3.28
Engine 600hp V-2K V12 diesel 600hp V-2 diesel 600hp V-2K V12 diesel 600hp V-2 diesel
Operational range on road (km) 250 250 250 225
Road Speed forward (km/h) 30 45 26 26
Fuel capacity (l) 600 975 600 600
Armor (mm) 30-90 30-82 [show]
30-110 30-110 [show]
Primary Armament 76.2mm F-32 gun 76.2mm ZiS-5 gun 152.4mm M-10 howitzer 152mm M-10T howitzer
Secondary Armament 3x 7.62mm DT machine gun 4x 7.62mm DT machine gun 3x 7.62mm DT machine gun 3x 7.62mm DT machine gun


In 1942, more modificaitons were made by Kotin's TsKB-2 (Central Design Bureau -2). The hull armor was increased from 75mm to 90mm. This new variant, designated the KV-1 Model 1942 was similar to Model 1941 but for angled overhang instead of a rounded one at the hull rear. Some tanks of these new variants also had a thicker cast turret with 120mm frontal armor. The increase in armor diminished the tank's mobility since no corresponding upgrades were made to the engine.

The KV-6 and KV-7 were Soviet heavy mechanized guns based on the KV chassis. They were developed by Kotin's team at Tankograd. The KV-6 had a 76.2mm gun and two 45mm guns. The KV-7 was armed with two 76.2mm guns. All the guns were placed in large ball mounts that are attached to fixed casemates. Both versions underwent trials in January 1942 and NKTP gave provisional permission for the production of the KV-7. However before mass-production took place, the project was terminated for an unknown reason.

KV-9 is a prototype armed by Dukhov's team with a 122mm M-30 howitzer. No mass-production took place because it had poor anti-tank capabilities.

The KV-13 was an effort to reduce the weight of the KV to the 30 tonne range while still withstanding the German 88mm gun. The KV-13 was known as the "universal tank" since Kotin hoped that it will replace the KV tank in production as well as the T-34. Trials conducted in the late summer of 1942 showed that the KV-13 had unreliable transmission. The project was cancelled.

Dukhov developed the KV-1S (skorostniy: speedy) with improved transmission designed in 1941 for the KV-3. The hull was lightened and the turret modified. Armor protection was reduced to gain speed and reliability. The commander was placed behind the gunner giving him a 360° vision cupola. The rear turret gunner was assigned the task of loading. It entered production in August 1942 to replace the KV-1.

During the fighting in the summer of 1943, Soviet tank commanders heavily criticized the firepower of the T-34 and KV tanks. While IS-1 production was beginning, the NKTP ordered Kirovskiy Works to produce a small quantity of KV-1S with the more heavily armored turret of the izdeliye 237 (IS-1), designated KV-85, until the IS-1 production picks up speed. A pair of fillets were added on either side to widen the hull for the greater diameter of the new turret. 130 KV-85s were produced in September and October of 1943.

KV-3 Obiekt 220 KV-85 Model 1943
Type (Role) Heavy Tank Heavy Tank
Origin Soviet Union Soviet Union
Years of production September to November 1943
Weight (Metric tonnes) 63 46
Crew 5 4
Length, gun forwards (m) 8.40 8.60
Width (m) 3.25 3.25
Height (m) 3.10 2.90
Engine 850hp V-2PUN 600hp V-2 diesel
Operational range on road (km) 250 250
Road Speed forward (km/h) 33 40
Fuel capacity (l) 600 975
Armor (mm) 30-100 [show]
30-160 [show]
Primary Armament 85mm F-39 gun 85mm D-5T gun
Secondary Armament 3x 7.62mm DT machine gun 3x 7.62mm DT machine gun



References: IHT, OW(1M39,1EM40,2M40), STCV