HMS R4: The Submarine Nicknamed 'The Slug'

The Build: Chatham

HMS R4 was built at Chatham Dockyard, launched on 8 June 1918 and commissioned on 23 August 1919, one of ten R-class submarines, an unusual and ambitious design conceived specifically as a hunter-killer submarine, prioritising submerged performance over surface speed at a time when most submarines were built the other way around.

She displaced 410 tons surfaced, armed with six 18-inch torpedo tubes and fitted with five hydrophones for detecting enemy submarines underwater.

Arriving Too Late

Like most of her sister R-class boats, R4 came too late to see any combat in the First World War, commissioning only after the armistice had already been signed, an all too familiar story for submarines rushed into an ambitious wartime building programme that simply could not keep pace with events.

A Distinctive Shape and a Grounding

R4 earned the affectionate nickname 'The Slug' from her crews, on account of her distinctive hull shape, and ran aground at Exmouth on 1 November 1926, though she was refloated ten and a half hours later without lasting harm. She spent much of her remaining service as a training target at the Portland anti-submarine school, valuable if unglamorous work helping to train the Navy's escort crews in submarine detection.

The End of Her Service

HMS R4 was sold on 26 May 1934 to Young of Sunderland for scrap, the only one of her class still afloat by then, bringing to a close the career of a submarine whose ambitious design had, in the end, found her most useful role not hunting enemy submarines but helping to train the sailors who would one day hunt them.