HMS M4

History
Name:	HMS M4
Builder:	Armstrong Whitworth
Laid down:	1917
Fate:	Sold as an incomplete hulk, 30 November 1921
General characteristics (as designed)
Class and type:	M-class submarine
Displacement:	1,594 long tons (1,620 t) surfaced 1,946 long tons (1,977 t) submerged
Length:	305 ft 9 in (93.19 m)
Beam:	24 ft 8 in (7.52 m)
Propulsion:	2 × 12-cylinder Vickers 1,200 hp (890 kW) diesel engines 4 × 800 hp (600 kW) electric motors 2 × 3-blade 5 ft 10 in (1.78 m) diameter propellers
Speed:	15 knots (28 km/h) surfaced 8–9 kn (15–17 km/h) submerged
Range:	Surfaced: 2,000 nmi (3,700 km) at 15 kn (28 km/h) 4,500 nmi (8,300 km) at 10 kn (19 km/h) Submerged: 9 nmi (17 km) at 17 kn (31 km/h) 80 nmi (150 km) at 2 kn (3.7 km/h)
Test depth:	200 ft (61 m)
Complement:	62
Armament:	1 × 12-inch (305mm)/40 cal Mark IX gun with 50 rounds 1 × 3 in (76 mm) Mk II HA anti-aircraft gun 4 × 21-inch (530mm) bow torpedo tubes with 4 reload torpedoes

HMS M4 was an M-class submarine of the Royal Navy built by Armstrong Whitworth, Newcastle Upon Tyne, and laid down in 1917. M4 was cancelled and sold as an incomplete hulk on 30 November 1921.

References

• Hutchinson, Robert (2001). Jane's Submarines: War Beneath the Waves from 1776 to the Present Day. London: HarperCollins. ISBN 978-0-00-710558-8. OCLC 53783010. 
• Colledge, J. J.; Warlow, Ben (2006) [1969]. Ships of the Royal Navy: The Complete Record of all Fighting Ships of the Royal Navy (Rev. ed.). London: Chatham Publishing. ISBN 978-1-86176-281-8. OCLC 67375475.