Ancient history


KV-1, KV-1s, KV-2, KV-3 and KV-85
Type: heavy tank.
Crew: 5 men.
Armament: a 76.2 mm gun (various types); 3 x 7.62mm DT machine guns. (Some tanks had in addition, a machine gun at the rear of the turret and a P40 anti-aircraft machine gun.)
Armour: from 75 to 100 mm, depending on the model.


length: 6.27 m;
width: 3.10 m;
height: 2.41m. (These dimensions vary slightly depending on the model.)
Weight: 47.5 t varying slightly depending on the model.
Ground pressure: 0.75 kg/cm2.
Power to weight: 12.7 hp, varies by model. Engine:Model V-2-K 12 cyl. water-cooled diesel, developing 608 hp at 2,000 rpm.


road speed: 35 km/h;
range: 250 km;
vertical obstacle: 1.20 m;
clean cut: 2.80 m;
slope: 36°
Service time: in the Red Army from 1940 to 1945.

The design bureau of the Kirov factories, headed by Kotin, had been commissioned to make a heavy tank “proof to shells”. After the disappointing experience of the multi-turreted T.35, he had returned to the concept of a single inertial machine armed with a powerful gun. The prototype was completed quickly, and enjoyed Stalin's personal approval. It received the acronym KV, initials of the Commissioner of Defense at the time, Marshal Klimenti Voroshilov.

On the first examples, the undercarriage was protected by armor plates which disappeared later with the adoption of a torsion bar suspension. less vulnerable than the previous type with leaf springs and pendulums.
The manufacture of the KV began in 1939 and a few pre-production units were engaged in Finland. The first serial copies manufactured by Kirov entered service in 1940.

The technique

The new heavy tank had a large turret. fairly well profiled housing a 76.2 mm piece firing armor-piercing and high-explosive shells. The average armor thickness was 75mm, reinforced on the front and gun mantlet.
The chassis itself as well as the superstructure had 75mm average armor thickness and the tank was given for being invulnerable to blows from all anti-tank guns in service at the time.
The chassis was made up of plates welded together, which simplified its machining. The undercarriage included high-resilience steel rim rollers, large tracks and an independent torsion bar suspension.
It proved particularly successful and remained virtually unchanged until the 'production of the KV stopped.
There were six rollers on each side and the track was made up of hardened steel shoes with a central guide:at the top of its stroke it was supported by three smaller diameter support rollers. The gipsy was at the back.

The tank was equipped with one of the first . large » Diesel engines, a 12-cylinder
500 horsepower engine, which gave it an honorable speed for its weight. This engine will be widely used later, on the T.34 medium tank in particular.
The volume of the turret made it possible to accommodate the commander, the gunner and the loader.
In addition to its main armament, the KV-1 had two machine guns firing one in pursuit and the other in retreat.
The internal layout was reminiscent of that of the T .34 with which, according to the Soviet trend towards standardization, the KV shared many mechanical components, armament and sighting system.


In parallel with that of the KV-I armed with the 76.2 mm gun, the production of the KV-II began, a monstrous machine with an enormous turret armed successively with a 122 mm howitzer then a 152 mm tube. Initially nicknamed "big turret" as opposed to the initial model called "small turret", this version received the baptism of fire on the Finnish front where it took part alongside its little brother in breaking the Mannerheim Line. Experience showed the superiority of the "small turret" design and the KV-I line was discontinued in mid-1941, after the 636th example of either type had been released.

In the meantime, the armament had evolved with the replacement of the 76.2 mm gun mod. 39 by mod. 40 at higher muzzle velocity. Appeared in 1940, this version (named KV-IA by the Germans) was initially assigned to unit commanders, with two episcopes in the turret, two others at the rear and three firing ranges for individual weapons.

The effectiveness of German anti-tank weapons led Soviet engineers to further strengthen the armor of the KV, which was done by welding or bolting new plates on the frame, the superstructure, the sides of the turret and in a few other particularly vulnerable points.
Called KV-IB, this version was subsequently replaced on the assembly lines by a molded turret variant (KV-IC°. with better anti-ballistic cleanliness and a thickness of increased armor (120 mm 1 The chassis was also reinforced with armor up to 130 mm in places. Naturally, the engine power had to be increased to 600 horsepower and the width of the tracks increased to compensate for the substantial increase in mass that passed from 40 tons to more than 47 tons.
The speed of the machine nevertheless fell to around 30 km/h.
This counter-performance was at the origin of a revision n of the program to improve the mobility of the tank. It resulted in the KV-ls version ( s =skorostnov. i.e.
fast), on which the thickness of the armor was reduced and the mechanics perfected to reach the speed of 40 km/h. A small number of Is were delivered to units from August 1942 to June 1943.

In reality, the decision had just been taken to reinforce the firepower of the tank by replacing its original turret with another, also machined by casting and armed with an 85 mm long gun. At the same time, the crew went from 4 to 5 men.
The new version, called KV-85, had a cupola for the tank commander (which increased its height to 2.70 m ), as well as a curved mask pierced with a circular hole for the new muzzle, while the armor of the chassis was. slightly reduced to keep the total mass within the limits imposed by the available power.

The turret retained its retreating machine gun, and this new tank rose to the occasion until the end of 1944.


The first KVs were used against the Finns, but in very small numbers. On the other hand, from the start of Operation Barbarossa, the Germans found themselves faced with some 500 of these tanks, thrown into the fray on June 24 on the southern front where they faced the armored vehicles of the Wehrmacht for the first time. , whose armament was powerless to puncture their armor.

Admittedly, the KV-I had its faults:the lack of longevity of the tracks and the discomfort of the cockpit, poor visibility with the hatches closed, and great difficulty of access and evacuation in the event of an emergency. The rear machine gun under spherical casemate constituted a final concession to the concept of the multi-turrets. The quality of the first turrets left something to be desired and presented various weak points such as projections forming real shell traps. They were not replaced by cast turrets until the second half of 1941.

The ratio of firepower and protection, mobility was in favor of the first two, which was classic for so-called breakthrough tanks. The engine, on the contrary, was of extremely advanced technology. with a high proportion of light alloy cast iron components.

All in all, it was a rustic tank, made to last and devoid of those faults which make a vehicle vulnerable to low temperatures. It proved to be particularly suitable for mass production in the new workshops hastily created in Tankograd after the invasion of Western Russia.
Of course, the appearance of this heavy tank provoked on the German side the commissioning of armored vehicles armed with ever more powerful guns, to arrive at the 88 gun of the Tiger, a new episode in the struggle between the shell and the armor which was not to be completed until May 1945.

On the side of the Soviet armored vehicles. the KV paved the way for the Stalin, the best of Russian heavy tanks, whose 122mm gun outweighed any form of German tank armament. as well as the commissioning of a number of excellent tank-casemates armed with even larger caliber guns.
In fact, it was the heavy tanks of the ’ generation that managed to counterbalance the qualitative superiority of German equipment during the second half of the (irar Patriotic War

Previous Post
Next Post