The SU-14 self-propelled gun started it's life as an element of the "Big triplex", proposed in 1931 for the Red Army mobile artillery. The concept was developed by the Military Academy of Motorization and Mechanization. Using the B-4 8in howitzer, T-28 tank transmission and elements of the T-35 superheavy tank and powered by the M-17T diesel, the device was tested in 1935 and 1936.
In the end of 1936, two SPG's were rearmed with a new Br-2 6in gun. Three years later, during the Winter War, they were armor-plated and sent to the front. Both were used in 1941 for defence of Moscow. One SU-14-1 (6in) is preserved at Kubinka proving grounds, Russia.