100 YEARS OF BARROW-BUILT RN SUBMARINES, 1901-2001
M CLASS, 1916-1932

MAIN PARTICULARS

Length overall                    259 ft 9 in
Beam                                24 ft 8 in
Depth, pressure hull            18 ft 8 in 
Displacement,
  surface                           1594 tons
  submerged                      1946 tons
Diving depth                      200 ft
No. of shafts                     2
Propellers                          3 blades, 5 ft 10 in diameter
Speed, surface:
  design                            16 knots 
  service                           15 knots 
Speed, submerged:
  design                            10 knots
  service                           8 to 9 knots
Endurance, surface:
  design                            2500 miles at 16 knots
  service                           2000 miles (full power)
                                       4500 miles (maximum)
Endurance, submerged:
  design                            10 miles at 10 knots
  service                           9 miles at 8+ knots
Armament                         * 4 18-inch bow tubes
                                       (8 torpedoes carried)
                                       1 12-inch gun
                                       1 3-inch gun
Complement:
  design                            64

* In M3 these were replaced by four 21-inch bow tubes, which were responsible for an overall increase in length of 10 feet.

© BAE SYSTEMS 2001