KV-1

The Kliment Voroshilov (KV-1) is a Soviet heavy tank developed between 1938 and 1939 by Zhozef Kotin and the TsKB-2 design bureau. It was designed as a successor to the multi-turreted T-35, following observations from the Spanish Civil War regarding the requirement for heavier armor protection. The vehicle was tested during the Winter War alongside the SMK and T-100 prototypes, where it demonstrated superior resistance to anti-tank weaponry. It entered service in 1939 and was produced in large numbers at the Kirov Factory and ChTZ.

The KV-1 features a single-turret configuration with torsion-bar suspension and wide tracks. Construction consists of welded and cast components. Early production models were armed with a 76.2 mm L-11 gun, while subsequent versions utilized the F-32 and ZiS-5 76.2 mm cannons. Secondary armament includes up to four DT machine guns. The vehicle’s armor provided protection against 3.7 cm KwK 36 and short-barreled 7.5 cm KwK 37 guns fielded by German forces during the initial stages of the 1941 invasion. German formations frequently required the use of 8.8 cm Flak guns or point-blank artillery fire to achieve penetrations. Mobility was limited by a transmission design based on a twenty-year-old Holt Caterpillar system, which made gear shifting difficult and steering unreliable. The vehicle's mass also restricted its ability to cross many bridges.

The Soviet Union was the primary operator, with units also serving in Polish forces. Finland, Romania, and Germany operated captured examples. During the Battle of Raseiniai in June 1941, KV-1 and KV-2 tanks were deployed to obstruct German armored columns. In August 1941 near Krasnogvardeysk, a detachment of five KV-1 tanks led by Lieutenant Zinoviy Kolobanov conducted an ambush from hidden positions, destroying a column of 43 German tanks.

Several variants were developed to address specific operational requirements. The KV-2 was an assault tank equipped with a 152 mm howitzer in an enlarged turret, produced in small numbers. The KV-1S was a lightened version featuring thinner armor, a smaller turret, and a planetary transmission intended to improve mechanical reliability and speed. In 1943, the KV-85 was introduced as a stopgap measure, mounting an 85 mm D-5T gun in a new turret. Other specialized versions included the KV-8 flamethrower tank. The KV series served as the developmental base for the IS (Iosif Stalin) tank family and self-propelled guns such as the SU-152.