In 1937 the Soviets issued a specification to replace the T-35 five turreted heavy tank then in service with the Red Army. The specification called for an armor thickness of 60 mm, and multiple turrets were in vogue with Soviet tank designers at the time. The first drafts of the SMK design were equipped with three turrets, but this was reduced to two when it was calculated that a three turret design could not be sufficiently armored.
The SMK was armed with 76.2 mm L-11 and 45 mm M1932 guns in superimposed turrets, along with two 7.62 mm and one 12.7 mm machine guns. Armor was 60 mm on the front, turrets, and sides, 55 mm on the upper surfaces. A 850 hp gasoline engine could drive the SMK at a maximum speed of 22 mph (35 kph). Overall weight was 60 tons, crew was seven.
The specification also produced two competing designs, the T-100 which was similar in layout having two superimposed turrets, and the more conventional KV-1 with a single turret. The SMK prototype and two examples each of the T-100 and KV-1 designs were formed into a heavy company of the 91st Tank Battalion for combat trials. The battalion saw action against the Finns near Summa on 17 – 19 December 1939. During the operation one of the KV-1 prototypes was evacuated after a Finnish round disabled its gun and the SMK prototype ran over a mine and was immobilized. Because of its size it eventually had to be abandoned. The Finns made attempts to tow the SMK from the area but also lacked anything heavy enough to move the 60 ton vehicle. When the Soviets secured the area in March 1940 they were finally able to recover the SMK, using six T-28 tanks. The SMK was transported back to the Soviet Union by rail, stripped of useable equipment and eventually scrapped. The KV-1 entered production as the Red Army’s new heavy tank.