HMS H47 was a British H-class submarine built by William Beardmore and Company at Dalmuir on the River Clyde. She was laid down on 20 November 1917, launched on 19 November 1918, and commissioned into the Royal Navy on 25 February 1919. She belonged to the large wartime H-class, a successful design intended for coastal patrol and anti-submarine operations.
Design
H47 displaced about 423 tons on the surface and 510 tons submerged. She carried a crew of 22 and was armed with four bow-mounted 21-inch torpedo tubes with eight torpedoes. Like other H-class boats, she was compact, reliable, and well suited to operations in British coastal waters.
Service Career
Because she entered service after the end of the First World War, HMS H47 did not see combat. Instead, her career was spent during the interwar period carrying out routine training exercises and fleet duties with Royal Navy submarine flotillas.
Although her service history was largely uneventful, she was typical of the submarines used to maintain the Royal Navy's submarine capability between the wars.
Collision and Loss
On 9 July 1929, H47 was returning toward Pembroke Dock via St George's Channel when she became involved in a disastrous collision with the larger L-class submarine HMS L12. The two submarines were operating in good weather near the Pembrokeshire coast, off Milford Haven.
During an overtaking manoeuvre, HMS L12 struck H47. The bow of L12 penetrated H47's hull, causing catastrophic flooding. The submarine sank extremely quickly, reportedly within about 15 seconds.
Of those aboard:
- 21 crew members were killed.
- Only 3 survived, including the commanding officer.
The wreck remains one of the Royal Navy's worst peacetime submarine accidents of the interwar years.
Memorial
Following the tragedy, personnel from the depot ship HMS Vulcan funded a memorial to the lost crew. The memorial was placed in the Royal Naval Church at Portland to commemorate those who perished.
Key Facts
- Name: HMS H47
- Class: H-class submarine
- Builder: William Beardmore and Company, Dalmuir
- Commissioned: 25 February 1919
- Crew: 22
- Lost: 9 July 1929
- Cause: Collision with HMS L12 off Milford Haven, Wales
- Casualties: 21 dead, 3 survivors
Notably, the commander of HMS Thetis during her fatal 1939 diving-trial disaster, Guy Bolus, had previously survived the 1929 loss of HMS H47, making him associated with two of the Royal Navy's most tragic submarine accidents.
