HMS H10

HMS H10 was a British H-class submarine of the Royal Navy, built by Canadian Vickers Co. at Montreal and commissioned in June 1915. She served during the First World War and was lost in the North Sea in January 1918 under circumstances that remain unknown. 

Construction and Design

HMS H10 was one of the first group of British H-class submarines, a design based on the American Holland 602 type. She displaced 364 tons surfaced and 434 tons submerged, measured 150 ft 3 in (45.8 m) in length, and carried a crew of 22 officers and men. 

Her armament consisted of:

• Four 18-inch bow torpedo tubes
• Six to eight 18-inch torpedoes carried
• A 6-pounder Hotchkiss quick-firing gun

Performance included:

• Surface speed: 13 knots
• Submerged speed: 10 to 11 knots
• Range: 1,600 nautical miles at 10 knots on the surface 

Service History

Following commissioning, HMS H10 joined the Royal Navy's submarine force operating from the east coast of Britain. She served with the 8th Submarine Flotilla at Harwich, conducting patrols in the North Sea against German naval and submarine activity. 

Loss

On 6 January 1918, under the command of Lieutenant M. H. Collier, H10 sailed from Yarmouth for a patrol northwest of the Dutch island of Vlieland. She was expected back on 14 January but failed to return. Search efforts by HMS Lurcher and HMS Firedrake found no trace of the submarine. She was officially recorded as lost on 19 January 1918 with all hands. The exact cause of her loss has never been established, although a mine or operational accident is considered likely.

Summary

A notable aspect of HMS H10's story is that, unlike many wartime submarine losses, no wreck has been positively identified and the precise circumstances of her disappearance remain a mystery