HMS Sentinel (P256): A Quiet Career From the Clyde to Gillingham

Constructed at Greenock, Missing the War Entirely

HMS Sentinel was built by Scotts Shipbuilding and Engineering at Greenock, laid down in November 1943, but not launched until July 1945 and not commissioned until the very end of that year, well after Japan's surrender had already brought the Second World War to a close.

She holds the distinction of being one of the small number of S-class submarines completed too late to be employed in any wartime role whatsoever, her entire early career consisting of trials and training off the west coast of Scotland before sailing to Portsmouth in February 1946.

A Quiet Peacetime Service

Sentinel's peacetime career is only thinly documented, though she is reported to have taken part in the Coronation Fleet Review at Spithead in 1953, and a family recollection preserved by former crew members describes a rather more personal moment, a crewman's son being christened aboard the submarine at Grand Harbour, Malta, in 1954, suggesting a period of Mediterranean deployment around that time.

Beyond these two glimpses, detailed records of her squadron assignments and exercises through the 1950s have proven difficult to trace.

Scrapped, Not Sold Abroad

It is worth correcting a suggestion sometimes made about this submarine, that she was sold on to the Danish Navy. No evidence for any such transfer survives in the record, and Denmark's genuine postwar submarine acquisitions from Britain were older U-class boats rather than S-class vessels like Sentinel.

She was instead sold for scrap in February 1962 and broken up at Gillingham in Kent, a quiet and unremarkable end befitting a submarine whose entire career, in truth, had been rather quiet and unremarkable from the very start.