Development started at the end of 1938. A prototype was produced in August 1939. The vehicle first saw combat in December 1939 at the Mannerheim Line. The tank was mass-produced from March 1940 through August 1942, with a total of 2,769 vehicles manufactured.
Time for the successive autoreloading of each shell into the magazine
The improved system allows the time to be decreased for autoreloading the next shell upon firing the loaded shell when the corresponding indicator is displayed
Characteristics are specified for Siege mode.
The technical characteristics are displayed for the charged turbine mode.
Characteristics are specified for Rapid mode.
Reload time of the first and second guns on double-barreled vehicles
Time to repair a damaged main/reserve track
Characteristics are specified for vehicles with crews trained to 100%.