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Kliment Voroshilov tank
KV1 model 1940 s ekranami (with appliqué), or KV1-E. The slogan on the turret side reads "Victory will be ours".
Type	Heavy tank
Place of origin	Soviet Union
Service history
In service	1939–45
Used by	Soviet Union
Wars	World War II
Production history
Designer	Zh. Kotin, TsKB-2
Designed	1938–39
Manufacturer	Kirov Factory, ChTZ
Produced	1939–43
Number built	about 5,219
Variants	KV-2, KV-8 flamethrower, KV-85
Specifications (KV-1 Model 1941)
Weight	45 tonnes
Length	6.75 m
Width	3.32 m
Height	2.71 m
Crew	5
Armour	90 mm
Primary armament	76.2 mm gun model F-34
Secondary armament	4×DT machine guns
Engine	12-cyl. diesel model V-2 600 hp (450 kW)
Power/weight	13 hp/tonne
Suspension	Torsion bar
Operational range	335 km
Speed	35 km/h

The Kliment Voroshilov (KV) tanks were a series of Soviet heavy tanks, named after the Soviet defense commissar and politician Kliment Voroshilov. At the time of the German invasion of the Soviet Union in World War II, about 500 KV tanks (with about 1,000 T-34 medium tanks) comprised a portion of Soviet tank forces which was clearly superior to German tanks of the period.

[edit] Development history

After disappointing results with the multi-turreted T-35 heavy tank, Soviet tank designers started drawing up replacements. The T-35 conformed to the 1920s notion of a 'breakthrough tank' with very heavy firepower, but poor mobility and armor protection. The Spanish Civil War demonstrated the need for much heavier armor on tanks, and was the main influence on Soviet tank design just prior to World War II.

Several competing designs were offered, and even more were drawn up prior to reaching prototype stage. All had heavy armor, torsion-bar suspension, wide tracks, and were of welded and cast construction. One of the main competing designs was the SMK, which lowered the number of turrets from the T-35's five to two, mounting the same combination of 76.2 mm and 45 mm weapons. When two prototypes were ordered though, it was decided to create one with only a single turret, but more armour. This new single-turret tank was the KV. The smaller hull size and single turret enabled the designer to add more armor while keeping the weight within manageable limits.

The KV-2 Heavy Artillery Tank's 152-mm howitzer was housed in an enormous turret. This prototype differs from the production version in several ways. It was called the Dreadnought by its crews (Zaloga 1984:118–19).

Abandoned KV-2, June 1941

When the Soviets entered the Winter War, the SMK, KV and a third design, the T-100, were sent to be tested in combat conditions. The heavy armour of the KV proved highly resistant to Finnish anti-tank weapons, making it more effective than the other designs. It was soon put into production, both as the original 76-mm-armed KV-1 Heavy Tank and the 152 mm howitzer-mounting assault gun, the KV-2 Heavy Artillery Tank.

The 45-ton KV outweighed most other tanks of the era, being about twice as heavy as the heaviest contemporary German tanks. The KV's strengths included armor that was impenetrable by any tank-mounted weapon then in service except at point-blank range, good firepower, and good traction on soft ground. It also had serious flaws: it was very slow and difficult to steer, the transmission was unreliable, and the ergonomics were poor, with limited visibility and no turret basket. Furthermore its weight tended to strain smaller Russian bridges. As more armor and other improvements were made without increasing engine power, later models were less capable of keeping up with medium tanks and had more trouble with difficult terrain.

[edit] Further development

By 1942, when the Germans were fielding large numbers of long-barrelled 50 mm and 75 mm guns, the KV's armor was no longer invincible, and other flaws came to the fore. While its 76.2 mm gun was adequate, it was the same gun as carried by smaller, faster, and cheaper T-34 medium tanks. It was much more difficult to manufacture and thus more expensive than the T-34. In short, its advantages no longer outweighed its drawbacks.

Nonetheless, because of its initial superior performance, the KV-1 was chosen as one of the few tanks to continue being built following the Soviet reorganization of tank production. Due to the new standardization, it shared the same engine, gun and transmission as the T-34, was built in large quantities, and received frequent upgrades.

When production shifted to the Ural Mountains 'Tankograd' complex, the KV-2 was dropped. While impressive on paper, it had been designed as a slow-moving bunker-buster. It was less useful in the type of highly mobile, fluid warfare that developed in World War II. The turret was so heavy it was difficult to traverse on non-level terrain, and it was expensive to produce. Only about 250 KV-2s were made, all in 1940-41, making it one of the rarer Soviet tanks.

KV-1 produced in 1942, displayed in Finnish Tank Museum in Parola.

As the war continued, the KV-1 continued to get more armour to compensate for the increasing effectiveness of German weapons. This culminated in the KV-1 model 1942 (German designation KV-1C), which was protected by very heavy armour, but lacked a corresponding improvement to the engine. Tankers complained that although they were well-protected, their mobility was poor and they had no firepower advantage over the T-34 medium tank.

In response to criticisms, the lighter KV-1S (Russian language: КВ-1С) was released, with thinner armour and a smaller, lower turret in order to reclaim some speed. Importantly, the KV-1S also had a commander's cupola with all-around vision blocks, a first for a Soviet heavy tank. However, the thinning-out of the armor called into question why the tank was being produced at all, when the T-34 could seemingly do everything a KV could do, much more cheaply. The Soviet heavy tank program was close to cancellation in mid-1943.

The appearance of the German Panther tank in the summer of 1943 convinced the Red Army to make a serious upgrade of its tank force for the first time since 1941. Soviet tanks needed bigger guns to take on the growing numbers of Panthers and the few Tigers.

A stopgap upgrade to the KV series was the short-lived KV-85. This was a KV-1S with a new turret designed for the KV-13, mounting the same 85 mm D-5T gun as the SU-85 and early versions of the T-34-85. Already-high demand for the gun slowed production of the KV-85 tremendously, and only 148 were built before the KV design was replaced. The KV-85 was produced in the fall and winter of 1943-44; they were sent to the front as of September 1943, and production of the KV-85 was stopped by the spring of 1944 once the IS-2 entered full scale production.

[edit] Successor

A new heavy tank design entered production late in 1943 based on the work done on the KV-13. Because Kliment Voroshilov had fallen out of political favour, the new heavy tank series was named the Iosif Stalin tank, after Iosif (Joseph) Stalin. The KV-13 program's IS-85 prototype was accepted for production as the IS-1 heavy tank. After testing with both 100 mm and 122 mm guns, the 122 mm gun was selected as the main armament of the new tank. Proving-ground tests showed that the larger A-19 122 mm gun could defeat the armour of the German Panther tank. The 122 mm fired a much larger HE round than the 100 mm and there was a surplus of production capacity for the gun and ammunition. The IS-122 design replaced the IS-85, and began mass production as the IS-2. The 85 mm gun saw service in the lighter SU-85 and T-34-85.

A destroyed Soviet KV-1 in Olonets, September 1941, during Continuation War

Some KVs remained in service right up to the end of the war, although in greatly diminishing numbers as they wore out or were knocked out. The 260th Guards Heavy Breakthrough Tank Regiment, based on the Leningrad front, operated a number of 1941-vintage KV-1s at least as late as the summer of 1944 before re-equipping with IS-2s. A regiment of KVs saw service in Manchuria in August 1945, and a few KV-85s were used in the Crimea in the summer of 1944. The Finnish forces had two KVs, nicknamed Klimi, a Model 1940 and Model 1941, both of which received minor upgrades in their service, and both of which survived the war. A single captured KV-2 was used by German forces in 1945 against US forces in the Ruhr.^{[citation needed]}

[edit] Models

Note: the Soviets did not recognize production models of KV-1 during the war, therefore designations like model 1939 (or M1939, Russian: Obr. 1939) were introduced later in military publications. These designations however are not strict and describe leading changes, while other changes might be adapted earlier or later in specific production batches. Designations like KV-1A were applied by the Germans during the war.

• KV-1
  • Model 1939
    

    KV-1 model 1939
    – First production models, these tanks were prone to frequent breakdowns, but were highly resilient to anti-tank weapons during the Winter War. These tanks were armed with the 76 mm L-11 tank gun, recognizable due to a recuperator above a barrel. Most tanks were lacking the hull machine gun. 141 were built.
  • Model 1940 (German designation: KV-1A) – Used the F-32 76 mm gun and a new mantlet. The main production model by the time of the German invasion.
  • Model 1940 s ekranami ("with screens") or KV1-E – with additional bolted-on appliqué armour and F-32 gun.
  • Model 1941 (KV-1B) – Up-armoured with 25 to 35 mm added to the turret, hull front and sides. Turret was now cast instead of welded. This tank was armed with the longer-barrelled F-34, and later ZiS-5 76.2 mm tank guns.
  • Model 1942 (KV-1C) – Fully cast turret with thicker armour or welded turret with thicker armour, again up-armoured and used an improved engine and the 76 mm ZiS-5 tank gun.
  • KV-1S – A lighter variant of late 1942 with higher speed, but thinner armour. A new, smaller, cast turret and redesigned rear hull were used. 1370 were built.
  • Panzerkampfwagen KV-IA 753(r) and Panzerkampfwagen KV-IB 755(r) - The KV-1 in German service. Some were fitted with a high-velocity KwK 40 L/43 75-mm gun, the same gun used in a Panzer IV Ausf F2.
• KV-85 – A KV-1S with the 85 mm D-5T gun in an IS-1's turret, with the ball mounted hull machine gun removed and the hole welded shut, 148 of these tanks were produced in the second half of 1943 until the spring of 1944 as a stopgap until the IS tank series entered production.
• KV-13 - Prototype designation for an advanced redesign of the KV series, which was renamed and resulted in the production of the IS-2.

[edit] Table of tank models

[edit] Variants

• KV-2 (334) – A heavy assault tank with the M-10 152 mm howitzer, the KV-2 was produced at the same time as the KV-1. Due to the size of its heavy turret and gun, the KV-2 was slower and had a much higher profile than the KV-1. The extra weight also increased the breakdown rate of the vehicle and production was soon halted. The original KV-2 was built on the chassis of the KV-1, while the improved KV-2B was built on that of the KV-1 M1940.
  • (Sturm)Panzerkampfwagen KV-II 754(r) - KV-2 in German service.
• KV-8 (42) – A KV-1 fitted with the ATO-41 flame-thrower in the turret, beside a machine gun. In order to accommodate the new weapon, the main gun was restricted to a smaller 45 mm Gun M1932, though it was disguised to look like the standard 76 mm.
• KV-8S (25) – A KV-1S with the coaxial turret machine gun replaced by an ATO-41 flame-thrower, and the main gun restricted to a 45 mm.
• KV-14 – Prototype designation for a 152 mm self-propelled gun, accepted for service as the SU-152.

[edit] Combat history

[edit] Raseiniai

A KV-1 enveloped in flames, knocked out near Voronezh in 1942.

When Operation Barbarossa began, the Red Army was equipped with 508 new KV tanks (Zaloga & Grandsen 1984:125). So effective was its armour that the Germans were incapable of destroying it with their tanks or anti-tank weapons and had to rely on air support and anti-aircraft artillery (flak) or 105 mm howitzers to knock them out. Most of these tanks and the effective T-34s were parcelled out to units in small numbers and poorly supplied, but at the Battle of Raseiniai they were used to good effect. On 23–24 June, a single KV-2 effectively pinned down elements of the German 6th Panzer Division for a full day at the bridgeheads of the Dubissa River below Raseiniai, Lithuania, playing a prominent role in delaying the advance of Panzergruppe 4 on Leningrad (Zaloga 1981:10–12, Zaloga 1995:17–20) until it ran out of ammunition and the crew was forced to abandon the tank and withdraw.

[edit] Krasnogvardeysk

On August 14, 1941, the vanguard of the German 8th Panzer Division approached Krasnogvardeysk (Gatchina) near Leningrad (St Petersburg), and the only Soviet force available at the time to attempt to stop the German advance was five well-disguised KV-1 tanks, dug in within a grove at the edge of a swamp. KV-1 tank no. 864 was commanded by the leader of this small force, Lieutenant Zinoviy Kolobanov.

German tank vanguard attack plan and positions of three soviet KV-1 tanks

Soviet newspaper article of 1941

German forces attacked Krasnogvardeysk from three directions. Near Noviy Uchkhoz settlement the geography favoured the Soviet defenders as the only road in the region passed the swamp, and the defenders commanded this choke point from their hidden position. Lieutenant Kolobanov had carefully studied the situation and readied his detachment the day before. Each KV-1 tank carried twice the normal amount of ammunition, two-thirds being armour-piercing rounds. Kolobanov ordered his other commanders to hold their fire and await orders. He did not want to reveal the total force, so only one exposed tank at a time would engage the enemy.

On August 14, the German 8th Panzer Division's vanguard ventured directly into the well-prepared Soviet ambush, with Kolobanov's tank knocking out the lead German tank with its first shot. The Germans falsely assumed that their lead tank had hit an anti-tank mine, and failed to realize that they had been ambushed. The German column stopped, giving Kolobanov the opportunity to destroy the second tank. Only then did the Germans realize they were under attack, but they failed to find the source of the shots. While the German tanks were firing blindly, Kolobanov knocked out the trailing German tank, thus boxing in the entire column.

Although the Germans correctly guessed the direction of fire, they could only spot Lieutenant Kolobanov's tank, and now attempted to engage an unseen enemy. German tanks moving off the road bogged down in the surrounding soft ground, becoming easy targets. 22 German tanks and 2 towed artillery pieces fell victim to Kolobanov's No. 864 before it ran out of ammunition. Kolobanov ordered in another KV-1, and 21 more German tanks were destroyed before the half-hour battle ended. A total of 43 German tanks were destroyed by just five Soviet KV-1s (two more remained in reserve).

After the battle, the crew of No. 864 counted a total of 135 hits on their tank, none of which had penetrated the KV-1's armour. Lieutenant Kolobanov was awarded the Order of Lenin, while his driver Usov was awarded the Order of the Red Banner. Later on, former Captain Zinoviy Kolobanov was again decorated by Soviet authorities, despite having been been convicted and downgraded after the Winter War for "fraternizing with the enemy." After the end of World War II, Lieutenant Kolobanov served in the Soviet occupation zone in Eastern Germany, where he was convicted again when a subordinate escaped to the British occupation zone, and was transferred to the reserves.

The battle for Krasnogvardeysk was covered up by Soviet propaganda. A monument dedicated to this battle was installed in the village of Noviy Uchkhoz in 1980, at the place where Kolobanov's KV-1 was dug in, due solely to the demands of the villagers. Unfortunately it was impossible to find a KV-1 tank, so an IS-2 heavy tank was installed there instead.[1]

The Soviet victory was the result of a well-planned ambush in advantageous ground and of technical superiority. Most of the German tanks in this battle were Panzer IIs, armed with 20 mm guns, and a few Panzer IIIs armed with 37 mm KwK 36 L/46.5 guns. The German tank guns had neither the range nor the power of the 76 mm main gun of a KV-1, and the narrower track width of the German tanks caused them to become trapped in the swampy ground.