After experience in the Russio-Finnish War with the T-100 and the SMK, it was found that they were too large and complex.1 Design work for the new heavy tank started in 1938.9Kotin showed design plans for a single turreted heavy tank to Stalin in August 1939 and it was approved to construct a KV prototype.1
This vehicle was originally called the Kotin-Stalin but was officially changed to the Klimenti Voroshilov5,8 / Klementi Vorishilov / Marshal Klimenti Voroshilov4,7/ Kliment Voroshilov3 (KV) after the Defense Commissar.
The KV-1 borrowed the hull, transmission, optics, and torsion bar suspension from the SMK.1
Initially the armor was welded.5
The KV-1s were used as assault or break through tanks.8,9
The driver sat in the middle.5,7 The radio operator / machine gunner sat on the left.5,7
The KV-1's vision was very limited for the commander and driver.1 The driver had a limited traverse periscope and a slit in the front that had laminated glass, but it was usually of poor quality and hard to see through.1 The commander of the KV-1 had two periscopes mounted in the top of the turret.1 He was also the gun loader.1
The engine was the same as the T-34 but with minor modifications.
Drive sprocket was at the rear.7
Initially the KV-1 was to have the 76.2 mm F-32, but due to delays the 76.2 mm L-11 was initially used.1
610 - 635 m/sec2
N. L. Duchov was the responsible designer from the S. J. Kotin design bureau that started development of the KV-1 in February 1939.2
The prototype was built at the Kirov Factory in February 1939.3,5 A wooden mockup was ready in April 1939.5 By September 1939 the first prototype was show to the General Staff.2,3,5 It was accepted in December 1939 / December 19, 19392,3, with production starting in February 1940.5
The KV-1 prototype was tested at the Kubinka test grounds outside of Moscow alongside the SMK and T-100.1
They came from the production lines in Leningrad and went straight to the front at Karelian.2 The factory was later moved to Chelyabinsk.2
Production: February 1940 - ?5, 1940 - 19431
1940: 1412, 2433
Prototype: Short 76.2 mm main gun.8 Three or four 7.62 mm machine guns.8 Armor was 3.94" / 100 mm thick.8
KV-1: The first models were prone to clutch and transmission faults.
KV-8: Flamethrower.1 Had 45 mm M32 gun installed in place of main gun and an ATO-41 flamethrower installed coaxially.1 It had 670 liters of oil and gave 52 - 55 / 1071 bursts of flames.2 It's range was about 46 meters. Used KV-1C chassis. Had 116 round of 45 mm, 2,772 rounds of MG, and weighed around 44 tons.
In February 1940, 22 / a platoon of KV-1s were sent to Finland4 for trials.9
The T-100, SMK, and KV-1 prototypes were apart of the 91st Tank Battalion of the 20th Heavy Tank Brigade and had their first combat near Summa from December 17 to 19.1
Despite hits from Finnish antitank weapons none were knocked out.3 It was also found that the diesel engine proved to be very reliable.3 The wide tracks allowed it to have excellent cross country performance.3
Invasion of the Motherland
By June 1941 there were 636 produced. By the Battle for Moscow (December 1941) 1,364.