M-class minesweeper (Germany)

M1940 series minesweeper in 1941
Class overview
Name:	M class
Operators:	Kriegsmarine Post-war:  United States Navy  Royal Navy  Soviet Navy  Royal Norwegian Navy  French Navy  German Navy  Marina Militare
Subclasses:	M1915 M1916 M1935 M1940 M1943
Built:	1937–1945 (not including older M1915 and M1916 ships)
Completed:	M1935 : 69 M1940 : 127 M1943 : 18
Lost:	M1935 : 35 M1940 : 63 M1943 : 1
General characteristics : M1935
Displacement:	682 long tons (693 t) standard 874 long tons (888 t) full load
Length:	68.4 m (224 ft 5 in)
Beam:	8.5 m (27 ft 11 in)
Draught:	2.65 m (8 ft 8 in)
Propulsion:	2 shaft VTE engines with exhaust turbines, 2 oil-fired boilers, 3,200 hp (2,386 kW)
Speed:	18 knots (33 km/h; 21 mph)
Complement:	113
Armament:	2 × 105 mm (4.1 in) guns 2 × 37 mm guns 2 × 20 mm guns
General characteristics : M1940
Displacement:	543 long tons (552 t) standard 775 long tons (787 t) full load
Length:	62.3 m (204 ft 5 in)
Beam:	8.5 m (27 ft 11 in)
Draught:	2.8 m (9 ft 2 in)
Propulsion:	2 shaft VTE engines with exhaust turbines, 2 coal-fired boilers , 2,400 hp (1,790 kW)
Speed:	16 knots (30 km/h; 18 mph)
Complement:	80
Armament:	1 × 105 mm (4.1 in) gun 1 × 37 mm gun 6-8 × 20 mm guns
General characteristics : M1943
Displacement:	582 long tons (591 t) standard 821 long tons (834 t) full load
Length:	67.8 m (222 ft 5 in)
Beam:	9 m (29 ft 6 in)
Draught:	2.7 m (8 ft 10 in)
Propulsion:	2 shaft VTE engines with exhaust turbines, 2 coal-fired boilers, 2,400 hp (1,790 kW)
Speed:	16 knots (30 km/h; 18 mph)
Complement:	107
Armament:	2 × 105 mm (4.1 in) guns 2 × 37 mm guns 6-8 × 20 mm guns

The M class were the standard minesweeper (German: Minensuchboot) of Nazi Germany's Kriegsmarine during World War II. The vessels were the primary force in Germany's harbor defense command and were organized administratively into minesweeper flotillas.

A total of 36 old units from World War I served in World War II. Some of these were converted to experimental ships, artillery school ships, fleet tenders or R-boat tenders, and 1 (ex-M109) was converted into a survey ship. In 1940, most of these converted vessels were re-designated as minesweepers again.

The first series; the M1935 were ordered in the late 1930s to replace worn out World War I vintage boats. These ships proved versatile and seaworthy. The vessels could also undertake convoy escort, anti-submarine warfare and minelaying tasks as well as minesweeping. However, the ships were very expensive and complicated to build, and their oil-fired boilers meant they suffered from the fuel shortages in the later years of the war. A total of 69 ships were built in eight different shipyards, between 1937 and 1941. 34 were lost during the war.

Although the M1935 was a very satisfactory vessel, it was complex and expensive to build and a simplified design was put into production in 1941. These ships had coal-fired boilers because of oil shortages. A total of 127 ships were built between 1941 and 1944, and 63 M1940 class ships were sunk during the war.

In 1943, Romania built four modified M1940 minesweepers at the Galați shipyard, named the Democrația-class.

This was a further simplified and slightly enlarged version of the M1940. These ships were designed for pre-fabrication and were produced in four versions:

Only 18 vessels were completed by the time the war ended.

After the end of the war the surviving ships allocated to the United States, Britain and the Soviet Union. Many were assigned to the German Mine Sweeping Administration under British control to clear the coast of Northern Europe of mines. Several were later also given to France and Norway, and two to Italy.