Soviet M-class submarine

Class overview
Operators:	Soviet Navy  Polish Navy
In service:	1933
In commission:	1933
Completed:	141
Lost:	33
General characteristics
Type:	Submarine
Displacement:	VI: 158 tons surfaced; 198 tons submerged VI-bis: 161 tons surfaced; 201 tons submerged XII: 206 tons surfaced; 256 tons submerged XV: 281 tons surfaced 351 tons submerged
Length:	VI to XII: 37.50 m (123 ft 0 in) XV: 50.0 m (164 ft 1 in)
Beam:	VI and VI-bis: 3.1 m (10 ft 2 in) XII: 3.3 m (10 ft 10 in) XV: 4.9 m (16 ft 1 in)
Draft:	VI and VI-bis: 2.6 m (8 ft 6 in) XII: 2.9 m (9 ft 6 in) XV: 3.6 m (11 ft 10 in)
Speed:	VI and VI-bis: 13.1 knots (24 km/h) surfaced; 7.4 knots (14 km/h) submerged XII: 14.1 knots (26 km/h) surfaced; 8.2 knots (15 km/h) submerged XV: 15 knots (28 km/h) surfaced; 10 knots (19 km/h) submerged
Complement:	VI to XII: 16-19 XV: 32
Armament:	VI to XII: 2 × 533 mm (21 in) bow torpedo tubes XV: 4 × 533 mm (21 in) torpedo tubes (2 bow, 2 stern) All series: 1 × 45 mm (2 in) semi-automatic gun

The M-class submarines, also Malyutka-class (Russian: Малютка; baby or little one), were a class of small, single-, or 1½-hulled submarines built in the Soviet Union and used during World War II. The submarines were built in sections so they could easily be transported by rail. The production was centered in the Gorky Shipyard on the Volga River, after which the sections were transported by railway to Leningrad for assembly and fitting out. This was the first use of welding on Soviet submarines.

Submarines of this class were in four series: VI, VI-bis, XII, XV. The number of VI and VI-bis series boats were almost equal. Series XII was a re-developed project with equivalent tactical characteristics. The first series were powered by one diesel engine and one electric motor. Series XV had developed separately with improved characteristics, including the main ballast in light hull and two shafts. These vessels were mainly used by the Black Sea Fleet and the Baltic Fleet.

Although the design was satisfactory, only limited results were obtained and losses were heavy with 33 submarines sunk between 1941 and 1945. Seven submarines were lost in the Black Sea, 4 depth-charged and sunk by Romanian warships (M-31 by destroyer Mărășești,M-58 by the destroyer Regina Maria,M-59 by the destroyer Regele Ferdinand and M-118 by the Romanian gunboats Ghiculescu and Stihi) and 3 were sunk in minefields laid by the Romanian minelayers Amiral Murgescu, Dacia and Regele Carol I. By 1945, some 111 M-class submarines had been completed, with another 30 XV-series completed between 1945 and 1947.

Two submarines of the early series of this class, along with two Soviet S-class submarines, (S-52 and S-53) and two Shchuka-class submarines (under lease, S-121 and S-123) were sold to the People's Republic of China in June 1954 as the foundation of the People's Liberation Army Navy Submarine Force. Both the M- and S-class submarines were sold to China, and two more M-XV series of this class (M-278 and M-279) were sold to China a few years later. Those purchased by China were renamed, but the two leased Shchuka-class submarines were not. The four M-class submarines bought by China were renamed National Defense # 21, 22, 23 (ex M-278) and 24 (ex M-279) respectively.

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Wikipedia