About KV Tanks (Kliment Voroshilov tank)

Kliment Voroshilov - 1 Heavy Tank

The Kliment Voroshilov (KV) tanks were a series of Soviet heavy tanks, named after the Soviet defense commissar and politicianKliment Voroshilov and used by the Red Army during World War II. The KV series were known for their extremely heavy armour protection during the early part of the war, especially during the first year of the German invasion of the Soviet Union.

They were almost completely immune to the 3.7 cm KwK 36 and howitzer-like, short barreled 7.5 cm KwK 37 guns mounted respectively on the early Panzer III and Panzer IV tanks fielded by the invading German forces. Until better guns were developed by the Germans it was often the case that the only way to defeat a KV was with a point-blank shot to the rear.

Prior to Operation Barbarossa (the German invasion of the USSR), about 500 of the over 22,000 tanks then in Soviet service were of the KV-1 type. When the KV-1 appeared, it outclassed the French Char B1,^[2] the only other heavy tank in operational service in the world at that time. Yet in the end it turned out that there was little sense in producing the expensive KV tanks, as the T-34 medium tank performed better (or at least equally well) in all practical respects. Later in the war, the KV series became a base for development of theIS (IS - Iosif Stalin) series of tanks.

Development

Kliment Voroshilov - 2 Heavt Tank

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 and armour protection, but suffered from poor mobility. The Spanish Civil War demonstrated the need for much heavier armor on tanks,^{[citation needed]} and was the main influence on Soviet tank design just prior to World War II.

The doctrine of Soviet deep battle called for the existence of relatively immobile, but heavily fortified, siege tanks that were supposed to keep pressure on enemy troops during the siege phase. Thus, the requirements for KV-1 were heavily skewed towards a potentially not-so agile, but heavy tank that was supposed to dominate the field.

Several competing designs were offered, and even more were drawn up prior to reaching prototype stage. All had heavy armour, torsion-bar suspension, wide tracks, and were of welded and cast construction. One of the main competing designs was the SMK, which in its final form had two turrets, mounting the same combination of 76.2 mm and 45 mm weapons. The designers of the SMK independently drew up a single-turreted variant and this received approval at the highest level. Two of these, named after the People's Defence Commissioner were ordered alongside a single SMK. The smaller hull and single turret enabled the designer to install heavy frontal and turret armour while keeping the weight within manageable limits.

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 KV outperformed the SMK and T-100 designs. The KV's heavy armour proved highly resistant to Finnish anti-tank weapons, making it more difficult to stop. In 1939 production of 50 KV was ordered. During the War, the Soviets found it difficult to deal with the concrete bunkers used by the Finns and a request was made for a tank with a large howitzer. One of the rush projects to meet the request put the howitzer in a new turret on one of the KV tanks.

Initially known as Little Turret and Big turret, the 76-mm-armed tank was designated as the KV-1 Heavy Tank and the 152 mm howitzerone as KV-2 Heavy Artillery Tank.

The KV's strengths included armor that was impenetrable by any tank-mounted weapon then in service except at point-blank range, that it had good firepower, and that it had good traction on soft ground. It also had serious flaws: it was difficult to steer, the transmission (which was a twenty year old Caterpillar design) was unreliable (and was known to have to be shifted with a hammer),ford shallow rivers, so they had to be left to travel to an adequate bridge. As applique armor and other improvements were added without increasing engine power, later models were less capable of keeping up to speed with medium tanks and had more trouble with difficult terrain. In addition, its firepower was no better than the T-34. It took field reports from senior commanders "and certified heroes", who could be honest without risk of punishment, to reveal "what a dog the KV-1 really was.

 and the ergonomics were poor, with limited visibility and no turret basket. Furthermore, at 45 tons, it was simply too heavy. This severely impacted the maneuverability, not so much in terms of maximum speed, as through inability to cross many bridges medium tanks could cross. The KV outweighed most other tanks of the era, being about twice as heavy as the heaviest contemporary German tank. KVs were never equipped with a snorkeling system to

While initially the Soviets made a lot of poor defense decisions, worsened by recent "cleansings" of Soviet military command, the KV-1 was unlike anything the German army had expected to encounter, and some of the battles against numerically superior Axis forces became legendary. Even though the operations of the KV family of tanks were severely hampered by restrictions due to its weight, it was a fearsome and formidable weapon through most of the Second World War.

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. The KV-1's side, top, and turret armor could also be penetrated by the high-velocity MK 101 carried by German ground attack aircraft such as the Henschel Hs 129, requiring the installation of additional field-expedient appliqué armour. The KV-1's 76.2 mm gun also came in for criticism. While adequate against all German tanks, it was the same gun as carried by smaller, faster, and cheaper T-34medium tanks. In 1943, it was determined that this gun could not penetrate the frontal armour of the new Tiger,^[8] the first German heavy tank, fortuitously captured near Leningrad. The KV-1 was also 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 similar engine (the KV used a 600 hp V-2K modification of the T-34's V-2 diesel engine) and gun (the KV had a ZiS-5 main gun, while the T-34 had a similar F-34 main gun) as the T-34, was built in large quantities, and received frequent upgrades.^{[citation needed]}

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 highly mobile, fluid warfare that developed in World War II. The turret was so heavy it was difficult to traverse on uneven terrain. Finally, it was expensive to produce. Only about 300 KV-2s were made, all in 1940-41, making it one of the rarer Soviet tanks.

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 had 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.^{[citation needed]}

In response to criticisms, the lighter KV-1S 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 the KV could do and 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 or Objekt 239. This was a KV-1S with a new turret designed for the IS-85, mounting the same 85 mm D-5T gun as the SU-85 and early versions of the T-34-85; 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 autumn 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.

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 (or IS-85, Object 237) heavy tank. After testing with both 100 mm and 122 mm guns, the D-25T 122 mm gun was selected as the main armament of the new tank, primarily because of its ready availability and the effect of its large high-explosive shell when attacking German fortifications. The 122mm D-25T used a separate shell and powder charge, resulting in a lower rate of fire and reduced ammunition capacity. While the 122mm armour piercing shell had a lower muzzle velocity than similar late German 7.5 cm and 8.8 cm guns, proving-ground tests showed that the 122mm AP shell could defeat the frontal armour of the German Panther tank, and the HE shell would easily blow off the drive sprocket and tread of the heaviest German tank or self-propelled gun. The IS-122 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.

Models

he Soviets did not recognize different production models of KV-1 during the war; designations like model 1939 (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

KV-1 1939

• Model 1939 – First production models, these tanks were prone to frequent breakdowns, but were highly resistant 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-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. Those captured and used by the German Army were known as (Sturm)Panzer kampfwagen KV-II 754(r) and often used for artillery observation due to its height.
• Т-150 (Object 150) - Experimental tank based on KV-1. Armor - 90mm, Weight - 51 tons. New 700 hp engine. Turret had a cupola but was in all other ways identical to the turret of the KV-1. One prototype was constructed in 1941 and was destroyed defending Leningrad.
• KV-3 (Objects 221, 222, and 223) - Experimental tanks based on KV-1. Longer chassis (7 rollers per side). The first design (Object 221) was never built, but it was supposed to have a 85mm gun. The same thing happened to Object 222, but it was supposed to have a F-32 76.2mm gun. The Objects 221 and 222 both retained the T-150's modified KV-1 turret. Object 223's hull was built and was tested with weights to simulated the new conical turret (housing a 107mm ZiS-6 cannon) that was designed for it. Object 223 had up to 120mm of sloped armor. The German invasion of Russia halted these plans and the only prototype hull was destroyed.^[9]
• KV-4 (Object 224) - A project for a Super-heavy tank. It was an in-case-of-emergency weapon and it was never to be built unless Russia started to lose the war with Germany. About 20 different designs were proposed, but it was cancelled in favour of the IS series tanks. Different versions would have been between about 85 and 110 tonnes. Armour from about 120 to 150 mm. Armament 107mm ZiS-6 cannon. Different variants had various auxiliary weapons: 45mm, 76mm cannons, machineguns and flamethrowers in addition to their main gun.
• KV-5 (Object 225) - A cancelled project for a heavy tank. Armament was to be a 107 mm ZiS-6 gun in a large turret and machine-gun in a small secondary turret. Weight was projected as about 100 tons, and the tank was to have 150-180mm of armor. Project development began in June 1941, however was cancelled due to the Siege of Leningrad, when all developmental operations at the Kirov Plant were halted. The project fell out of favour from the more advanced heavy tank designs, and no prototype was built.
• KV-6 (Object 226) - According to an order to the Chelyabinsk Tractor Factory in June 1941, A tank indexed KV-6 was to be designed from the KV-1 with 90mm of armor and a 76mm gun model 1940. Nothing ever came of this design.
• KV-7 (Object 227) - Experimental selfpropelled gun based on KV-1 armed with 3 cannons: two 45mm model 1932/34 and one 76mm F-34 (this version of the KV-7 was also called the U-13). 200 rounds of ammunition was carried for the 45mm guns and 93 rounds for the 75mm gun, and the tank had 100mm of frontal armor. One unit was produced and tested in 1941.

KV-7-2 (improved variant)(also called U-14) had two 76mm F-34 cannons, and 85mm of frontal armor. Vehicles were not taken in service primarily because they could not fight tanks (the KV-7s only had 15 degree gun traverse to each side) and they could not combat concrete bunkers due to the small caliber of the guns. After the failure of the KV-7 it was decided to put one 152mm gun in the casemate instead of there smaller guns; this led to the development of the SU-152.

• U-18 - Experimental selfpropelled gun. KV-7 armed with 152 mm ML-20 howitzer. Vehicle was projected in 1941. Wooden mockup was constructed. Project was cancelled, but this vehicle was a first step towards SU-152 design.
• U-19 - Experimental selfpropelled gun armed with 203mm B-4 cannon. The vehicle was to have 75mm of frontal armor, 60mm on the side, and the roof was to be 30mm (the roof would have been removable to facilitate loading). It was projected to weigh 66 tons, but the project was not very successful and was cancelled within a year.
• SU-152 - See http://en.wikipedia.org/wiki/SU-152
• ZiK-20 - The ZiK-20 was very similar to the U-19, but had 105mm of frontal armor, and 75mm of side armor and was to mount a ML-20 gun. By the time was wooden mockup was made the KV-1 was phased out of production. However just before the project was cancelled a blueprint was draw up to equip the ZiK-20 with a Br-2 152.4mm gun; and to offset the weight the frontal armor was to be reduced to 75mm (or 60mm on the KV-1S chassis)
• SU-203 - SU-152 equipped with 203mm M-4 mortar, the SU-203 was never built.
• 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 76.2mm gun was replaced with a smaller 45 mm Gun M1932, though it was disguised to look like the standard 76 mm (The cannon was placed inside 76mm tube).
  • KV-8S (25) – The same as KV-8, but based on KV-1S. Was equipped with ATO-42 flamethrower (improved version of ATO-41).
  • KV-8M - Upgraded version of KV-8S. Was equipped with two flamethrowers. Two prototypes was constructed.
• KV-9 (Object 229) - A KV-1 with short 122mm U-11 cannon. One prototype was constructed and proved in 1941.
• KV-10 (Object 230) - Also known as KV-1K. A KV-1 with 4 rocket launchers on the sides of hull. Each launcher contained two 132mm M-13 rockets. Early variant of KV-1K had 2 launchers on the back of hull, each contained 6 rockets. One prototype was constructed and tested in 1942. Not taken in service.
• KV-11 (Object 231) - KV-1 armed with 85mm F-30 cannon. Projected in 1942. Not built.
• KV-12 (Object 232) - Experimental chemical tank. Was equipped with 4 external toxin tanks on the back of chassis. Tanks surrounded with 30mm armor. Not taken in service.
• KV-13 (Object 233) - Prototype of a medium tank. Designation for an advanced redesign of the KV series, which was resulted in the production of the IS series.
  • IS Model 2 - A KV-13, with turret and armanent from KV-9. One prototype was construcred and proved in 1943. Tank had lost competition to IS Model 1 and was not taken in service.
• KV-14 (Object 236) – Prototype designation for a 152 mm self-propelled gun, accepted for service as the SU-152.
• KV-85 – A KV-1S with the 85mm D-5T cannon in a new 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. This tank had its original turret, but later models were equipped with IS-1 turret.
  • KV-85G - KV-1S with 85mm S-31 cannon. Turret and mantlet remained from conventional KV-1S. This variant was a competitor of KV-85 during proving. It lost competition and was not taken in service.
  • KV-152 - A KV-1S with short 152mm S-41 cannon. One prototype was made in 1943. Not taken in service.
  • KV-100 - A KV-85 with the 100mm D-10T cannon. One prototype was made in 1944. Not taken in service.
  • KV-122 - A KV-85 with the 122mm D-25T cannon. One prototype was made in 1944. Not taken in service.
• KV-220 (Object 220) - Experimental tank based on KV-1. Longer chassis (7 rollers per side). Armor - 100mm. New 850 hp V-2SN engine with turbocharging. New diamond-shaped turret. 85mm F-30 cannon. One prototype was constructed in 1941, and was destroyed.

Source : Wikipedia