HMS H42 was a British H class submarine that sank with the loss of all twenty four members of its crew after an accidental collision in March 1922. The submarine was built by Armstrong Whitworth on the Tyne. She was laid down in September 1917 and was commissioned on the 1st May 1919.
Like all of the later H-class submarines, H42 had a total length of 171 feet, a beam of 15 feet 4 inches and a draught of 39 feet. She displaced 423 tons surfaced and 510 tons whilst submerged and was powered by a diesel engine providing a total power of 480 horsepower and propelled by two electric motors each providing 320 horsepower. The use of her two motors allowed the submarine to steam at 11 knots surfaced or 9 knots whilst dived. With a range of 2,985 nautical miles.
H42 was fitted with an anti-aircraft gun and four 21 inches torpedo tubes. The torpedo tubes were fitted to the bows and the submarine was usually loaded with eight 21 inch torpedoes and was crewed normally by a complement of twenty two officers and men.
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 when she surfaced unexpectedly a short distance ahead of the destroyer HMS Versatile cruising at 20 knots.
HMS Versatile immediately went to full astern on her engines and put her helm hard over to port, but had not yet begun to turn when she rammed H42 abaft the conning tower, almost slicing the submarine in half. H42 sank immediately with the loss of all hands.
A subsequent investigation found H42 to be at fault for surfacing too close to HMS Versatile.
On 23rd March 2022, in remembrance of the loss of HMS H42, William Price (a nephew of a crew member) unveiled a plaque at Europa Point, Gibraltar and the Royal Navy laid a wreath on top of the wreck. The chairman of WRS, Ian Atkinson was honoured to attend the ceremony
