The M-class submarines, also Malyutka class (; baby or little one), were a class of small, single-, or 1½-hulled coastal 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.

History

1930s to 1940s

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. M-103 disappeared in the Baltic Sea in mid-August 1941. The wreck was discovered in the late 1990s during a NATO minesweeping training exercise. Seven submarines were lost in the Black Sea, four depth-charged and sunk by Romanian warships (M-31 by the flotilla leader , M-58 by the destroyer Regina Maria, M-59 by the destroyer Regele FerdinandDonald A Bertke, Gordon Smith, Don Kindell, World War II Sea War, Volume 5: Air Raid Pearl Harbor. This Is Not a Drill, p. 63 and M-118 by the Romanian gunboats Ghiculescu and StihiMikhail Monakov, Jurgen Rohwer, Stalin's Ocean-going Fleet: Soviet Naval Strategy and Shipbuilding Programs 1935-1953, p. 266) (both M-58 and M-59 however are also reported as lost on Romanian laid mines,Antony Preston, Warship, Conway Maritime Press, 2001, p. 75 while M-31 was also claimed by mines or a German vesselDonald A Bertke, Gordon Smith, Don Kindell, World War II Sea War, Vol 8: Guadalcanal Secured, 2015, p. 77 ) and three were sunk in minefields laid by the Romanian minelayers , Dacia and Regele Carol I.Mikhail Monakov, Jurgen Rohwer, Stalin's Ocean-going Fleet: Soviet Naval Strategy and Shipbuilding Programs 1935-1953, pp. 265 and 266 By 1945, some 111 M-class submarines had been completed, with another 30 XV-series completed between 1945 and 1947.

Cold War Two submarines of the early series of this class, along with two s, (S-52 and S-53) and two s (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 in 1956.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.

Modern times An M-class submarine was discovered near Tallinn in May 2012. The submarine is located in Tallinn Bay between the islands of Aegna and Naissaar, at an approximate depth of . It is believed to be M-216, which was intentionally sunk in the area in 1962 for training purposes. Divers have confirmed that many components, including the periscope, are missing. It is also believed that the training exercise may have been ordered as a result of several deadly submarine accidents in the 1950s. One such accident happened near Paldiski, where the entire crew of M-200 died during a failed rescue operation.In Estonian: The submarine in the bay of Tallinn is of the Malyutka class.

In July 2015, another M-class (series XII) submarine was found in the Black Sea by divers off the Romanian coast at Costinești, at an approximate depth of . It is believed to be either M-34 or M-58, both being lost to Romanian minefields. The submarine is buried in sand up to the deck level and also completely filled with sand, making any further identification almost impossible. The upper part of the hull shows a pretty high level of damage - many ribs are exposed. The aft hatch was partially opened. The hull is in one piece, with the conning tower and deck gun intact.

In April 2025, after a 20-year search, M-class submarine M-49 was found in the Peter the Great Gulf. M-49 had gone missing on 16 August 1941.

Versions Series VI 30 submarines constructed between 1932 and 1934 were 37.5 m long and displaced 201 tons submerged (158 tons surfaced).

M-1 M-2 M-3 M-4 M-5 M-6 M-7 M-8 M-9 M-10

M-11 M-12 M-13 M-14 M-15 M-16 M-17 M-18 M-19 M-20

M-21 M-22 M-23 M-24 M-25 M-26 M-27 M-28 M-51 M-52

Series VI-bis 20 submarines built in four sections between 1934 and 1936) were 37.5 m long and displaced 202 tons submerged (161 tons surfaced). Name Commissioned FateM-43 6 November 1935 Was M-82 until 1939. Stricken 28 November 1950. Transferred to China in 1954 as 205.M-44 27 November 1935 Was M-84 until 1939. Stricken 28 November 1950. Transferred to China in 1954 as 200.M-45 4 November 1935 Was M-85 until 1939. Stricken 28 November 1950. Transferred to China in 1954 as 201.M-46 4 November 1935 Was M-86 until 1939. Stricken 28 November 1950. Transferred to China in 1954 as 202.M-47 10 June 1935 Was M-53 until 1939. Transferred to China in 1954 as 203.M-48 19 October 1936 Was M-56 until 1939. Transferred to China in 1954 as 204.M-54 14 October 1936 Ran aground on 10 December 1941; later salvaged and repaired. Decommissioned 18 October 1944 and stricken 19 December 1944.M-55 17 October 1936 Stricken 19 December 1944.M-71 24 August 1935 Scuttled at Libau on 24 June 1941 to prevent capture.M-72 24 August 1935 Struck a mine in the Gulf of Finland on 28 June 1941, causing heavy damage. Decommissioned to reserve in August 1941 and stricken on 2 December 1944.M-73 24 August 1935 Decommissioned to reserve in August 1941. Stricken 2 December 1944.M-74 24 August 1935 Bombed and sunk by German aircraft at Kronstadt on 23 September 1941. Raised in 1942, but deemed not worth repairing. Stricken 2 December 1944.M-75 24 August 1935 Decommissioned to reserve in August 1941. Stricken 2 December 1944.M-76 24 August 1935 Decommissioned to reserve in 1941. Stricken 2 December 1944.M-77 19 June 1936 Served on Lake Ladoga in 1943. Stricken 22 February 1949.M-78 19 June 1936 Sunk by west of Widawa (now Ventspils) on 23 June 1941.M-79 15 July 1936 Served on Lake Ladoga in 1943. Stricken 22 February 1949.M-80 15 July 1936 Scuttled at Libau on 24 June 1941 to prevent capture.M-81 15 July 1936 Sunk by mine off Vormsi, Estonia on 1 July 1941.M-83 8 November 1935 Scuttled off Libau on 27 June 1941 while returning to port.

Series XII 46 submarines built in six sections between 1936 and 1941 were 44.5 m long, and displaced 258 tons submerged (206 tons surfaced).