HMS H31 was an H-class submarine of the Royal Navy. Built during the First World War, she outlived many of her contemporaries and continued serving into the Second World War before being lost with all hands in December 1941.
Construction
- Builder: Vickers Ltd., Barrow-in-Furness
- Laid down: 19 April 1917
- Launched: 16 November 1918
- Commissioned: February 1919
The submarine belonged to the later H-class boats, derived from the successful Holland design and intended primarily for coastal and patrol duties.
Second World War Service
At the outbreak of war, H31 was already twenty years old, but she remained useful for patrols and anti-submarine exercises. She operated from bases including Portland and later Scottish ports, conducting patrols in the English Channel, North Sea and western approaches.
Combat Success
H31 achieved at least one notable wartime success when she torpedoed and sank the German auxiliary anti-submarine vessel UJ 126 (Steiermark) off the Dutch coast in July 1940.
Final Patrol
In December 1941, H31 was assigned to operations connected with the surveillance of the German battlecruisers Scharnhorst and Gneisenau, then based at Brest in occupied France. British submarines were deployed in the Bay of Biscay to intercept any attempt by the German ships to break out.
H31 sailed from Falmouth on 19 December 1941 for a patrol approximately 250 nautical miles north of Cape Finisterre. After separating from her escort near Wolf Rock, she was never seen again.
She failed to reach a rendezvous point on 24 December and was declared overdue shortly afterwards.
Loss
The exact cause of the loss remains unknown. Possible explanations include:
- Striking a German mine.
- Contact with drifting mines.
- An accident at sea.
The submarine was presumed lost between 19 and 24 December 1941, and all 22 crew members perished.
