KV designation was for Klimenti Voroshilov, the Soviet defense commissar. Intended as the replacement for the T-35 heavy; design work began on the KV-1 in 1938. It incorporated many of the features of the T-34. Subsequent models of the KV-1 incorporated extra armor, new cast turret, and upgraded engine. The KV-85 version, produced beginning in 1943, mounted the 85mm gun. The KV-1 was an important step forward toward the next generation of Soviet tanks, including the Joseph Stalin.
In the heavy tank category two new multi-turret designs, the T-100 and SMK were built in small numbers to replace the T35. Ready in 1940, they were used on the Finnish front but proved too bulky to be wholly successful. At Stalin’s suggestion the basic design was changed to give a single turret, a shorter hull, and thicker armour. The resultant vehicle was the KV (Klimenti Voroshilov) produced in 1940. This again was developed through several variants and proved to be an excellent design, bigger and better armed than the heaviest German tanks of 1941.
Production of the KV started in 1940 with the result that 508 were available in May 1941 and by the time it came to an end in 1943 it amounted to more than 4700 tanks. The KV was obviously produced in much smaller numbers than the T-34 and it proved to be far less important. It had armour up to 75mm instead of 45mm thick and a three-, instead of a two-man turret but this resulted in its weight being 42.5 tons while its main armament was exactly the same as that of the T-34. Its thicker armour was intended to make the KV capable of attacking enemy positions in the face of contemporary anti-tank weapons and, in fact, initially provided it with a high degree of immunity. But its immunity was bound to be short lived and, as more effective anti-tank weapons appeared, the KV lost whatever advantage it had over the T-34. The continued use of the KV was briefly justified in 1943 when it was rearmed with an 85mm gun. But shortly afterwards the same gun was also mounted in the T-34 and. as there was little sense in producing two different tanks with the same main armament, the KV-85 was abandoned. In its place came the 46 ton IS-2, or Stalin, heavy tank. This tank was similar to the KV but had thicker armour of up to 120mm on the hull front, partly because it dispensed with the hull machine gunner of the KV. However, the most important difference between it and the KV was its much more powerful, 122mm gun.
Models
Note: the Soviets did not recognize different production models of KV-1 during the war, therefore designations like model 1939 (or 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
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-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) Panzerkampfwagen KV-II 754(r)
Т-150 (Object 150) – Experimental tank based on KV-1. Armor – 90mm. New 700hp engine. Turret design and armament remained form KV-1. One prototype was constructed in 1941.
KV-220 (Object 220) – Experimental tank based on KV-1. Longer chassis (7 rollers per side). Armour – 100mm. New 850hp V-2SN engine with turbocharging. New diamond-shaped turret. 85mm F-30 cannon. One prototype was constructed in 1941.
KV-222 (Object 222) – Experimental tank based on KV-1. Longer chassis (7 rollers per side). Armour – 90mm. New 850hp V-2SN engine. One prototype was constructed in 1941.
KV-3 (Object 223) – Experimental tank based on KV-1. Longer chassis (7 rollers per side). New 850hp V-2SN engine. 130 mm armor. New conic turret. 107mm ZiS-6 cannon. One prototype was constructed and tested in 1941.
KV-6 (Object 226) – Experimental flame tank based on KV-1. Flamethrower was mounted inside hull to the right from driver. Visual feature of this tank is armoured box on the front of chassis to the right from driver. One vehicle was constructed and proven in 1941.
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-85G – KV-1S with 85mm S-18 cannon. Turret and mantlet remained from conventional KV-1S. This variant was a competitor of the KV-85 during testing. It lost competition and was not taken in service.
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-152 – A KV-85 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-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-9 (Object 229) – A KV-1 with short 122mm U-11 cannon. One prototype was constructed and tested in 1941.
KV-10 (Object 230) – Also known as KV-1K. A KV-1S with 4 rocket launchers on the back of hull. Each launcher contained two 132mm M-13 rockets. One prototype was constructed in 1942. Not taken in service.
KV-12 (Object 232) – Experimental chemical tank. Was equipped with 4 external toxin tanks on the back of chassis. Tanks surrounded with 30mm armour. 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.
KV-14 (Object 236) – Prototype designation for a 152 mm self-propelled gun, accepted for service as the SU-152.
IS Model 2 – A KV-13 with turret and armament from KV-9. One prototype was constructed and proven in 1943. Tank had lost competition to IS Model 1 and was not taken in service.
Manufacturer: Kirov, Chelyabinsk
Crew: 5
Armament: 1 x 76.2mm (3-inch) gun L-11 (early versions had the short .30-caliber length; later models had the 40-caliber; the KV-85, produced beginning in 1943, mounted 1 x 85mm/3.34-inch gun); 3 x 7.62mm DT machine guns
Weight: 95,874 lbs. (increased weight in subsequent upgraded armour models; KV-85 version weighed 101,400 lbs.)
Length: 22’7”
Width: 10’8”
Height: 8’9”
Armour: maximum 77mm; minimum 25mm (Model 1941 (KV-1B) and Model 1942 (KV-1C) had additional armour totalling 130mm)
Ammunition storage and type: 111 x 76.2mm; 3,024 x 7.62mm
Power plant: V-2K V-12 550-hp diesel engine (600-hp in the C Model)
Maximum speed: 22 mph
Range: 93 miles
Fording depth: 4’11”
Vertical obstacle: 3’3”
Trench crossing: 8’10”
Special characteristics (positive/negative): excellent design with balance of armor, armament, and speed; chief problems were manoeuvrability and mechanical reliability.
