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KV-1S Heavy Tank

A modified version, the KV-1S, was introduced in late 1942 to restore mobility and allow easier cooperation with T-34 units. With lighter armor than the standard models the KV-1S proved unpopular, but its improved power plant and suspension played an important role in the development of Soviet tanks in the second half of the war.

KV-1S ("S" - speed) was a lightweight modification of the KV-1 tank serially produced from September 1942 in Chelyabinsk. One of the weak points of the KV-1 was heavy congestion due to excessive armor protection. As a result, it affected the speed and maneuverability of the tank. On the new modification, armor protection was reduced, the gearbox was modified, a commander's turret was installed to improve visibility. To fight the German Tiger and Panther tanks that appeared in 1943, an 85 mm caliber gun was installed. The vehicle received the designation KV-85. Tanks of the KV series were produced until 1943, until they were replaced by a more sophisticated vehicle.

Tank units constantly received complaints about the weightedness of the KV-1 tank, which entailed not only technical problems. After the march, even a few units of KV the road along which they passed, became difficult for other types of equipment, including tracked. The bridges that could withstand the 47-48-ton machine were mentioned earlier - there were cases when the HF was carried out into the river together with a structure that was clearly not designed for such loads. With regard to the potency of a heavy tank on loose soil or marshland, in this regard, the KV was much inferior to the T-34, in which this indicator also did not differ for the better. All these factors led to the fact that in the spring of 1942 work was begun to alleviate the heavy tank, in order to increase its mobility and speed performance. The design of the new modification was carried out by CTZ specialists, who were faced with a difficult task. Based on the experience of the battles, which showed that 75 mm anti-tank guns or 88 mm anti-aircraft guns did not save even 100-mm armor from concentrated fire, it was decided to partially weaken the armor protection of the turret and hull. Now the thickness of its frontal part was 82 mm, the sides and roof - 40 mm, the stern - 75 mm.

The turret was cast and had a completely new, streamlined shape with a single hatch. According to the experience of German tank builders, According to the experience of German tank builders, a commander's pinnacle with five glass blocks was introduced, which allowed the tank commander to conduct a circular observation of the battlefield without the use of optical instruments. The thickness of the armor of the frontal part of the body corresponded to the usual KV-1 and was 75 mm, however, the sides were covered with 40-mm armor. To reduce the weight of the tank, lightweight track rollers were used, and the tracks of the cast tracks were reduced to 608 mm.

One of the most important moments was the installation of a new gearbox, designed by engineer NF Shashmurin. She had 10 gears (eight forward and two reverse) and was equipped with a multiplier. In addition, a new main friction and onboard transmissions were installed on the tank. The composition of weapons did not change, although due to the shortage of ZiS-5 weapons on serial tanks, the F-34 was installed — in this case, the ammunition was increased from 90 to 114 projectiles. On the modified tank, the commander's seat was moved from the right front to the left rear corner, behind the gunner’s back. The duty of the loader was transferred to the stern machine gun, and the machine gun itself was moved to the left, which allowed the tank commander to fire it.

In sum, these activities allowed to bring the mass of the modified KV-1 to 42,500 kg and increase its mobility. On state tests, which took place from July 28 to August 20, 1942, the new heavy tank showed the best speed characteristics at virtually the same level of body armor. On the last day of testing, it was put into service under the designation KV-1s (“speed”) and from the end of the same month it began to replace the conventional KV-1 on the conveyor. Only in September 1942, the Chelyabinsk plant manufactured 180 production tanks, but by the end of the year the production of the KV-1s began to decline. The reason for this step was quite understandable - aside from the more powerful armor, the heavy tank had no advantages over the average T-34.

The Battle of Kursk was the last major battle where KV-1 heavy tanks were used in massive quantities. The 203rd Separate Heavy Tank Regiment of the 18th Tank Corps (it had the usual KV-1s, but there are allegations that there were assault KV-2), which was at the disposal of the Voronezh Front, was used only occasionally and significantly in the course of the battle did not have. At the same time, the neighboring 15th and 36th Guards TTP, armed with the British infantry tanks “Churchill”, took an active part in the famous battle of Prokhorovka, although they lost almost all of their vehicles. As a result, the 15th regiment moved to the KV-1s, and the 36th regiment was again replenished with British tanks. In total, the Central Front had 70 tanks of this type, and there were 105 units on them in Voronezh.

Even before the end of the Kursk battle, heavy tanks engaged the breakthrough of the so-called “Mius-Front” in July-August 1943. As part of the 1st Guards Tank Regiment KV-1s, they participated in storming the enemy strongholds, as a result operations were lost 10 tanks (2 burned, 2 were destroyed and 6 were blown up by mines).

The last Guards Tank Regiment on the KV-1s was formed in January 1944, but in the fall, outdated tanks were transferred to secondary sectors of the front, and the “Guardsmen” were transferred to more powerful IS-2s. However, the KV-1s fought until the very end of the war. As part of the 1452 Sap (self-propelled artillery regiment), they took part in the liberation of the Crimea, but due to heavy battles from five tanks of this type, not a single one reached the final stage of the operation. The remaining KV-1s of other tank units then fought in Poland and Germany, where they took the last battle in the spring of 1945.

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Page last modified: 09-03-2019 17:59:41 ZULU