M class Minesweepers - Allied Warships of WWII - uboat.net

The above specifications are for M 1.
M 2 same specifications as M 1 except;
Displacement: 205 BRT
Lenght: 29.7 m
Speed: 10 knots

M 3 and M 4 same specifications as M 1 except;
Displacement: 230 BRT
Lenght: 29.75 m
Speed: 10 knots
Power: 450 HP 

Books dealing with this subject include:

Arctic Convoy PQ8, Michael Wadsworth, 2010
Hitler's Forgotten Flotillas, Lawrence Paterson, 2017
HMS Trenchant, Hazlett, Arthur, 2001
Minesweeper, Melvin, Michael J., 1992
U-Boat Far from Home, Stevens, David, 1997
World War II American High Speed Minesweepers DMS-1 through DMS-18, Borchers, Duane D., Sr.,