HMS H47 was built by William Beardmore and Company, Dalmuir. She was laid down on 20 November 1917 and was commissioned on 25 February 1919.

On the morning of 9 July 1929 HMS H47 (Lt R J Gardner) was returning to Pembroke Docks from the Irish Sea by heading South through St Georges Channel when two larger and faster “L Class” submarines (HMS L12 & L14), that were returning to Portsmouth from the West Coast of Scotland, undertook an overtaking manoeuvre. Good visibility and calm seas meant it should have been the case of the faster “L” boats passing safely down the port side of H47. Tragically it all went wrong and HMS L12 rammed H47 and her bow penetrated the hull of H47. Within 15 seconds H47 listed sharply to starboard and sank quickly with the loss of 21 of her crew. There were only three survivors, including the Captain.

A memorial to her lost crew was purchased by subscription from the personnel of her depot ship, HMS Vulcan, and emplaced near the altar of the Royal Naval Church, Portland.