a type of early Soviet submarine, the construction of which was begun in 1927 according to plans made by a group of designers headed by B. M. Malinin. Surface displacement; 989 tons; submerged displacement, 1,400 tons; length, 86 m; draft, 3.8 m; surface speed, 14.7 knots (27.2 km/hr); underwater speed, 9 knots (17 km/hr); cruising range, 7,500 miles; armament: one 100-mm gun, one 45-mm gun, and six fore and two aft torpedo tubes; crew, 60 men.

The construction of the first three submarines of the Dekabrist type was completed in 1931, and they became part of the Baltic Fleet. In 1933 their base was moved to the Northern Fleet. Submarines of the Dekabrist type actively participated in the combat operations of the Northern and Black Sea fleets during the Great Patriotic War (1941-45). The submarine D-3 of the Northern Fleet was awarded the Order of the Red Banner on Jan. 17, 1942. It received the title of guards on Apr. 3, 1942, and became the first guards Red Banner submarine in the Soviet Navy.