Heavy Tank KV-1
Strengths and Weaknesses
When it first appeared, the KV-1 is combination of mobility, strong armour and firepower made it one of the most powerful tanks in the world, probably only rivalled or surpassed by the Soviet medium T-34. Its frontal hull and turret armour were 75mm (2,95in) and 90mm (3,5 in) thick respectively, making it invulnerable to many existing antitank guns, other than at point blank range. Although weighing 43.6 tonnes (43 tons), a series of factors meant that it was relatively fast and mobi le. capable of achieving 35km/h (21,8mph) on roads, and approximately 13km/h (8,1 mph) across country. This was achieved by a refined version of the SMK suspension which mounted the 12 wheels independently on torsion bars, and using wide tracks to lower ground pressure. Adequate power was provided by a 373kW (500bhp) model V-2K, V-12 diesel engine. Combined with a range of 160km (99 miles) by road, and 100km (62 miles) across country, the KV-1 tank, in conjunction with the even more mobile T-34, seemed to give the Red Army the tools it required to implement the theory of Deep Operations.
Initially it was intended to arm the KV-1 with the F-32 76,2mm gun (3in) developed by the Grabin team, but delays in supply meant that the short L-11 76,2mm (3in) was used instead. Secondary armament comprised three DT machine guns, one co-axial, one in the from hull, and one in the rear of the turret. A crew of five was required to operate the tank.
Impressive as it was, the Heavy Tank KV-1 did suffer from a number of problems, and not all had been solved by the time production ended in 1943. Initial models had major clutch and transmission problems, seriously impeding its mobility. Changing gear involved halting the tank, pteventing it from ever attaining high speed. US Army tests on the transmission at their Aberdeen Armoured Testing ground in 1942 noted that it was years out of date and had been rejected by the US Army because it was painfully hard for the driver to work. Engine performance was further reduced by inefficient air filters. Overall, these fac tors made the tank hard to steer.
The crew compartment was far from ideal and hampered performance in combat. When the hatches were closed, the driver and commander had severely restricted vision, making it difficult for them to carry out their tasks effectively. The driver's periscope had a limited traverse, and the laminated glass in his forward slit visor was often of such poor manufacture that it was difficult to see through. The commander had two periscopes of a reasonable standard mounted in the top of the turret, but his ability to direct the driver, radio operator and gunner were significantly hampered by having to double up as gun loader. All of this resulted in poor tactical mobility and coordination on the battlefield.
During the course of the war, refinements were made to the basic KV-1 design in order to iron out its flaws and extend its service life. In 1940 the KV-1 tank model 1940 appeared, armed with the higher velocity F-32 76,2mm (3in) gun firing a longer round and a new, more powerful 447kW (600bhp) V-2 engine. Pans of the turret and hull armour were in creased by the crude and unpopular technique of bolting 35mm (1,3in) armour plates to them. This was caused by G. Kulik's bizarre belief that German tanks were armed with massive-calibre guns, and with the short-term inability of Soviet industry to produce thicker armour, he and Stalin wanted to counter this phantom threat. The turret plates were replaced later in the year when stronger welded turrets were produced.
In 1941 the ZiS-5 76.2mm (3in) gun was fitted for the first time to the KV-1. Similar to the F-34 76.2m (3 in) gun mounted on the T-34/76 medium tank, it was significantly more powerful than the KV's existing F-32 76.2mm (3in). This was the result of another successful appeal by Kotin's team to Stalin and the Main Defence Committee (GKO). Upgrading the KV with the F-34 ended the illogical situation of the Red Army's medium tank being armed with a more powerful gun than its heavy tank. The earlier model's angular and weaker welded turret was replaced with a stronger cast version that was also easier to manufacture. The rear turret overhang was also eliminated.
A unique development of the KV-1 was its adaptation to a flamethrower role, designated KV-8. Work began on this project after the Russo-Finnish War showed that light tanks adapted to being flamethrowers were too vulnerable to antitank fire. The KVS 76.2mm (3in) gun was replaced with a 45mm (1,77in) gun in order to make room for the ATO-41 flamethrower. A special gun jacket was added to camouflage the thin barrel of the weapon and prevent it being knocked out immediately by rhe enemy. The ATO-41 fired 3 shots every 10 seconds, and the KV-8 carried enough fuel for 107 shots. Later on the KV-8S was developed by re-equipping the KV-1-S.