In 1942, the demand for mobile direct artillery support of the infantry was still unanswered in the Red Army.
As the
T-60 and
T-70 light tanks were becoming obsolete and the new ZiS-3 gun had proven versatile and effective, both parts were combined at Gorkiy Auto Zavod (»GAZ«) in late 1942.
However, the new design, initially named
SU-12 and built from December 1942 on, proved nothing less than a disaster.
The two
GAZ-202 truck engines used were installed on either side driving a single track each, unsynchronized.
The closed fighting compartment lacked an effective ventilation causing the crew to be poisonded by the gun and engine emissions.
Hence, production was stopped in March 1943 after only 360 units had been completed.
However, the lessons were learned by the Russian designers resulting in the modified and improved
SU-76M.