KV-1 Heavy Tank

Despite the KV-1 heavy tank being able to withstand most German weaponry, poor technical characteristics were it’s Achilles heel during the Great Patriotic War. After the launch of ‘Operation Barbarossa’, the Germans were shocked to realize that the Red Army had tanks they couldn’t do anything about. The KV-1 was invincible and no match for most of the Wehrmacht’s weapons. When the Wehrmacht invaded Soviet territory, over 400 KV-1 tanks were deployed to face the enemy. Neither German tanks, nor anti-tank artillery, couldn’t destroy these “Russian monsters” or “Ghosts”, as the Germans called them. The only way was to allow a KV-1 come closer than 500 meters, which was akin to suicide.

The appearance of the future heavy tank did not immediately crystallize. Attempts were made to modify the existing T-28, to create multi-turret T-100 and SMK (an abbreviation on behalf of Sergei Mironovich Kirov), to equip the future KV (stands for Klim Voroshilov) with two guns. When discussing the layouts at a meeting of the Main Military Council at the end of 1938, with the participation of Comrade Stalin, they came to the conclusion: it is enough to leave one tower and one gun, and strengthen the armor due to the saved weight.

The primary Soviet heavy tank throughout the first half of the war was the KV-1. More than 4,000 KV-1s were built before production ceased in 1943. At the time of its introduction in 1940, the KV-1 was one of the most powerful tanks in the world, though it was eclipsed by the superlative performance of the T-34. While the two vehicles shared similar armament, the KV-1 was less mobile, suffering from an incredibly poor transmission and greater weight of armor.

In the theory of a deep offensive operation developed by Soviet military experts in the early 1930s, based on the rethinking of the experience of the Great War, considerable attention was paid to the issues of advance prepared defensive line of the enemy. The frontal breakthrough task was supposed to be accomplished during an army offensive by concentrating a large number of rifle units and formations reinforced with medium and heavy tanks, engineering means when massing forces, means and fire of artillery and attached artillery on a sector, in the conditions of their dense support by the actions of front-line aviation.

A special role in the success of such an operation was to be played by multi-turret heavy tanks, advancing ahead of the rifle units, hitting the enemy's firepower, located in the long-term fortifications. Later self-propelled artillery mounts - the self-propelled artillery guns - coped with these tasks. For these purposes, in the USSR in the first half of the 1930s, three-turret medium tanks T-28 and five-turret heavy T-35 were developed and mass-produced. If for its time the T-28 was a good machine, then the T-35 was not at the stage of its creation complying with the requirements of the modern combined-arms battle. The vehicle was initially distinguished by large dimensions, low mobility, obviously insufficient motor potential and it was unreasonably oversaturated with onboard armament. It is hard to imagine in what case a 45 mm gun could be used, located in the rear turret with a sector of fire back and 90 degrees to the right along the tank.

After summarizing the first experience gained by Soviet tankmen during the Spanish Civil War, the T-35 was completely unsuitable for combat use due to weak armor protection, which was unable to withstand the anti-tank artillery systems that appeared on the battlefield. Taking into account these factors, in the middle of 1937, the Armored Directorate of the Red Army (ABTU of the Red Army) formulated a tactical and technical task (TTZ) to create a heavy three-turreted heavy tank with armor, armed with one 76 mm and two 45 mm tank guns and eight machine guns. The design was proposed to be carried out using units and units of the chassis and transmission T-35. The developer chose KB Kharkov Locomotive Plant. (KhPZ imeni Comintern).

Proposing to create a modern heavy tank on the basis of the T-35, which did not have the potential for further modernization, ABTU set a difficult task for the designers. In addition, the KhPZ design bureau was loaded with work on technological support for the production of BT-5 and BT-7 tanks, and their modifications, with the development of a new-generation medium tank. For these reasons, the process of designing a new tank moved with difficulty and by the beginning of 1938 did not go beyond the conceptual design.

Work on the KB tank was initially carried out by the group of designer Afanasy Ermolaev, but it soon became clear that they were unable to work out several projects at once (SMK, T-100, finished the serial T-28 tank), and Kotin formed another group of designers. At its head, he put engineer Nikolai Dukhov (later his deputy, an active participant in the work on the atomic project, three times Hero of Socialist Labor), who had previously been mainly engaged in the preparation of the production of a passenger car, and also participated in the improvement of the Universal tractor. Nevertheless, his talent as a design engineer was so versatile that he effortlessly moved from one task to another, everywhere achieving high results.

In April 1938, the TTZ was transferred to SKB-2 of the Leningrad Kirovsky Plant (LKZ, now OAO Kirovsky Zavod) and to the Design Bureau of Plant No. 185 (Leningrad). In SKB-2, development work (R&D) was organized under the general supervision of LKZ Chief Designer J.Ya.Kotin, directly above the creation of the project worked team under the leadership of lead designer N.V.Zeitz, with the active participation of leading engineers A.S.Ermolaeva and N.L.Spirit. In the design bureau of plant number 185, the project was managed by E.Sh.Paley.

By August 1938, draft designs were ready in both design bureaus. On October 10, the project acceptance drawings and wooden models of QMS tanks (Sergey Mironovich Kirov - project LKZ) and Product 100 (T-100 - project of plant No. 185) were presented to the ABTU acceptance committee.

The SKB-2 LKZ project provided for the construction of a 55-ton heavy tank with armament including one 76 mm and two 45mm guns located in three turrets with an AM-34 carburetor engine with a capacity of 850 hp. The armor of the tank consisted of a set of armor plates 30-75 thick mm, while the undercarriage basically repeated the undercarriage of the T-35, with the exception of the suspension design. The new project provided for the torsion type (on the T-35 - on the spiral springs). The length of the QMS was 8750 mm.

The T-100 tank was 58 tons, with the layout and composition of cannon armaments similar to the QMS, with an AM-34 engine, armor of 20-60 mm with a balancer type suspension on leaf springs 8495 mm long. Despite significant deviations from the TTZ requirements, the acceptance committee approved the projects by its decision. In early December 1938, the projects were considered at a joint meeting of the Politburo of the Central Committee of the CPSU (b) and the Defense Committee, after which some changes were made to the TTZ ABTU. In particular, it was decided to abandon one of the 45 mm turret installations in order to reduce the mass of machines. In addition, at the suggestion of the director LKZ I.M. Zaltsman and chief designer J.I. Kotin, it was decided to make a prototype tank with the characteristics of the QMS, but with one turret.

The fact is that the design of a single-mounted version of the tank was carried out at SKB-2 from the end of October 1938 as a graduation work of a group of graduates of the Military Academy of Mechanization and Motorization of the Red Army (VAMM Red Army). From the beginning of February 1939, the SKB-2 team began a full-scale development of the KV heavy tank project (Klim Voroshilov, the one-turret tank project was called). On 27 February 1939 the requirements of TTZ for the design of KV were agreed and approved . In addition, by the decision of the Committee of Defense No. 45 cc from the same date, the responsibility for the creation of the single-turret heavy tank was formally assigned to the management of SKB-2 as soon as possible. Using the reserves of the VAMM graduate group, the LKZ designers already by April 9, 1939. submitted to the commission a draft design and a wooden mock-up of a full-size tank, and by September 1, the first prototype KV was made, which was immediately submitted to factory tests.

The appearance of the KV on the battlefield at the beginning of World War II put German tankers into a state of shock: 37-mm or 50-mm anti-tank or tank guns practically did not hit the armor of Kotin's vehicles, only 88-mm anti-aircraft guns were effective. Nevertheless, in the summer and autumn of 1941, the design of the Soviet tank remained unfinished, the transmission often could not withstand the loads and failed. There were few KVs destroyed by enemy fire, but in the conditions of retreat, many tanks, even with minor breakdowns, had to be abandoned or destroyed, since there were no means to evacuate or repair them. In terms of cross-country ability, mobility, and low cost of production, the KV was much inferior to the average T-34, which also represented a very difficult target for the enemy.

Early periods of the war were marked with many episodes of the heroic deeds by KV-1 tanks and their crews. Thus, in June 1941, near the Lithuanian city of Raseiniai, one such tank engaged in a battle with the whole German 6th Tank Division. Suddenly, appearing in the rear of the enemy, it ran out of fuel and simply stopped in the middle of the road, cutting all the division’s communications and traffic. After destroying 12 supply trucks and several 50-mm anti-tank guns, it paralyzed the enemy for 24 hours, surviving all attacks, with only the 88-mm anti-air gun that could deal with this “Russian monster”.

During the defense near Krasnogvardeysk (now Gatchina), the crew, led by Senior Lieutenant Zinovy Kolobanov from the 1st Panzer Division, perfectly camouflaged the tank and on August 20 knocked out 22 tanks in the enemy column from an ambush. In response, KV Kolobanova received at least 135 hits, but there was not a single through hole (the company commander was awarded the Order of the Red Banner for this battle).

Among the most productive tank aces of the 16th Army and the entire Western Front was Lieutenant Pavel Gudz. His battalion held the defenses west of Istra and, having taken a good position near the village of Nefedyevo, at dawn on December 5, a single KV opened direct fire on units of the 10th German Panzer Division. At the end of the three-hour battle, Soviet tankers knocked out ten armored vehicles of the enemy, and counted 29 dents on their own, but not a single shell penetrated the armor through (for the heroically fought battle, Lieutenant Gudz was awarded the Order of Lenin).

However, the KV-1 wasn’t destined to become the best tank of World War II. While perfectly-armored, it was completely technically unreliable. A raw, unfinished design, poor quality of the transmission and shoddy air filter often meant that some tanks didn’t even reach the battlefield and would keep stalling. Some crews were even forced to abandon the broken down tanks. The huge KV-1 tanks were also a true menace for roads and bridges. After the 45-ton-weight “monster” crossed these surfaces, it was almost impossible for other military equipment to follow in its path.

Before the start of World War II, the gearbox and transmission of the KV-1 tank had not been brought to optimal working condition, so the reliability and quality of the tanks left much to be desired, especially when a large series was produced. Various changes and simplifications (cast towers, tracks and rollers, additional fuel tanks, etc.) led to an increase in the weight of the vehicle to about 48 tons. Numerous complaints began to come from the troops. The State Defense Committee (GKO) demanded that Kotin reduce the weight of the vehicle to 45.5 tons, then another three tons.

Soviet designers tried to fix all these weaknesses and in spring 1942, a modernized version - the KV-1S - appeared. It was lighter (just 42,5 tons) and had slightly thinner side armor (60 mm instead of 75 mm). Despite this, it still remained impenetrable to enemy fire while outperforming its predecessor in speed - 45 km/h instead of 35 km/h on the road. An improved transmission also gave it more reliability.

What the KV-1 lacked in mobility, it more than made up for in protection. The front hull armor was 75 millimeters thick, while that on the turret was 90 millimeters, making the KV-1 essentially invulnerable to almost all antitank weapons at any but pointblank range. While thick, the armor was not sloped as on the T-34, limiting the future potential of the tank. In time, the increasing lethality of German antitank weapons would lead to additional armor, further decreasing KV-1 mobility.

However, all these preparations were in vain. In late summer 1942, the Wehrmacht began to use its heavy Tiger tanks, en masse. They instantly made the KV tanks obsolete. Thus, during one short fight near Leningrad, three Tigers easily destroyed 10 KV-1S tanks, without a single loss among their ranks.

The appearance in late 1942 - early 1943 of the new German heavy tank "Tiger" put the Soviet tankers in a disadvantageous position: the enemy easily pierced the armor of our vehicles, while he himself remained practically invulnerable. In May 1943, the GKO set the task for tank and artillery designers to develop tank and self-propelled 85-mm guns with anti-aircraft ballistics. These guns were supposed to be installed in the regular turret of the KV-1S tank (this is how the KV-85 appeared - the first 22 tanks were built in August, and its combat use began in September) and on the new heavy tank IS (Joseph Stalin).

The production of the KV-1 (this is how the KV was called after the appearance of the KV tank "with a big turret" or KV-2) was organized in February 1940 at the LKZ. In accordance with the joint Decree of the Central Committee of the CPSU (b) and the Council of People's Commissars of the USSR of June 19, 1940, the Chelyabinsk Tank Plant was connected to the production of HF. In total for 1940 and the first half of 1941, 637 KV-1 and KV-2 tanks were manufactured. Serial production of KV tanks of all modifications was completed at the end of the summer of 1943 in connection with the start of production of IS-1 tanks. During this period, 4,775 HF tanks of all modifications were built.

And then the Kliment Voroshilov tank gave way to the new Joseph Stalin tank (IS). The most armored and deadliest Allied heavy tanks of WWII, a “hunter of cats” (Panthers and Tigers), IS tanks became the weapon, that finally finished off Nazi Germany.