Comparing: KV-3 vs. FV201 (A45)

Developed on the basis of the KV heavy tank, the vehicle initially had very few differences from the mass-produced model. It underwent field trials in January–February 1941. Eventually, several crucial changes were made to the design, greatly boosting the combat characteristics of the vehicle. By July 22, 1941, chassis and engine development was completed. According to some sources, in the fall of 1941, the vehicle was equipped with a serial KV turret and sent to the front.

Developed starting in 1944 by English Electric as a possible replacement for the A43 Black Prince. Some components were unified with the A41 Centurion. In 1948 trials of a prototype were started. The prototype mounted a Centurion Mk. II turret and a 17-pounder gun. Due to changes in Armored Forces policy and doctrine, development proceeded no further. However, the design later served as a basis for several post-war heavy tanks.