HMS H42

HMS H42 was a British H class submarine that sank with the loss of all 24 of its crew after an accidental collision in 1922.^[1] The sub was built by Armstrong Whitworth, Newcastle Upon Tyne. She was laid down in September 1917 and was commissioned on 1 May 1919.

History
United Kingdom
Name	HMS H42
Builder	Armstrong Whitworth, Newcastle Upon Tyne
Laid down	September 1917
Launched	21 October 1918
Commissioned	1 May 1919
Fate	Sunk in collision 23 March 1922
General characteristics
Class and type	H class submarine
Displacement	423 long tons (430 t) surfaced 510 long tons (518 t) submerged
Length	171 ft 0 in (52.12 m)
Beam	15 ft 4 in (4.67 m)
Propulsion	1 × 480 hp (358 kW) diesel engine 2 × 620 hp (462 kW) electric motors
Speed	11.5 knots (21.3 km/h; 13.2 mph) surfaced 9 knots (17 km/h; 10 mph) submerged
Range	2,985 nmi (5,528 km) at 7.5 kn (13.9 km/h; 8.6 mph) surfaced 130 nmi (240 km) at 2 kn (3.7 km/h; 2.3 mph) submerged
Complement	22
Armament	4 × 21 in (533 mm) bow torpedo tubes 8 × 21 inch torpedoes

On 23 March 1922, under the command of Royal Navy Lieutenant Douglas Staley, H42 was practising torpedo attacks against British destroyers steaming off Europa Point, Gibraltar,^[2] when she surfaced unexpectedly only 30 ^[3] or 120^[4] yards (27 or 110 metres) – sources differ – ahead of the destroyer HMS Versatile. Versatile, making 20 knots, went to full speed astern on her engines and put her helm over hard to port, but had not yet begun to answer her helm when she rammed H42 abaft the conning tower, almost slicing the submarine in half. H42 sank with the loss of all hands. An investigation found H42 at fault for surfacing where she did against instructions.^[4][5]

Design

Like all post-H20 British H-class submarines, H42 had a displacement of 423 long tons (430 t) at the surface and 510 long tons (520 t) while submerged.^[6] It had a total length of 171 feet (52 m),^[7] a beam of 15 feet 4 inches (4.67 m), and a draught of 12 metres (39 ft).^[8] It contained a diesel engines providing a total power of 480 horsepower (360 kW) and two electric motors each providing 320 horsepower (240 kW) power.^[8] The use of its electric motors made the submarine travel at 11 knots (20 km/h; 13 mph). It would normally carry 16.4 long tons (16.7 t) of fuel and had a maximum capacity of 18 long tons (18 t).^[9]

The submarine had a maximum surface speed of 13 knots (24 km/h; 15 mph) and a submerged speed of 10.5 knots (19.4 km/h; 12.1 mph). Post-H20 British H-class submarines had ranges of 2,985 nautical miles (5,528 km; 3,435 mi) at speeds of 7.5 knots (13.9 km/h; 8.6 mph) when surfaced.^[6][8] H42 was fitted with an anti-aircraft gun and four 21 inches (530 mm) torpedo tubes. Its torpedo tubes were fitted to the bows and the submarine was loaded with eight 21 inches (530 mm) torpedoes.^[6] It is a Holland 602 type submarine but was designed to meet Royal Navy specifications. Its complement was twenty-two crew members.^[6]

References

1. "Submersible Sunk; 24 Lost— British H-42 Rammed by Destroyer Versatile During Maneuvers", The Washington Post, March 24, 1922, p. 1
2. Navy Net: Remembrance Sunday: H42 is Still On Patrol
3. "Struck at Right Angles— H 42 Rises 30 Yards Ahead of Destroyer", The Manchester Guardian, March 24, 1922, p. 9; Eyres Monsell, the Lord of the Admiralty, read a telegram to the House of Commons that was received from the Gibraltar command saying "The only further details yet known are as follows: H 42 came to the surface thirty or forty yards ahead of Versatile, which was steaming twenty knots and rammed the submarine about the conning tower at right angles." It is possible that the speculation on modern websites of "120 yards" is based on a misinterpretation of 120 feet (or 40 yards).
4. "H42". rnsubs.co.uk. Retrieved 28 September 2022.
5. Richardson and Hurd 1923, p.31.
6. Gardiner, Robert; Gray, Robert (1985). Conway's All the World's Fighting Ships 1906-1921. London: Conway Maritime Press. p. 92. ISBN 0-85177-245-5.
7. Derek Walters (2004). The History of the British 'U' Class Submarine. Casemate Publishers. pp. 2–. ISBN 978-1-84415-131-8.
8. 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. Retrieved from Naval-History on 20 August 2015.
9. J. D. Perkins (1999). "Building History and Technical Details for Canadian CC-Boats and the Original H-CLASS". Electric Boat Company Holland Patent Submarines. Retrieved 20 August 2015.

Bibliography

• Hutchinson, Robert (2001). Jane's submarines : war beneath the waves from 1776 to the present day. London: HarperCollins. ISBN 9780007105588.
• Richardson, Alexander and Archibald Hurd. (editors). Brassey's Naval and Shipping Annual 1923. London, William Clowes, 1923.