March 18th - On This Date - RN Submarine Service

1916	G2	Submarine HMS G2 completed
1916	Swordfish	Submarine HMS Swordfish launched
1917	H28	Submarine HMS H28 laid down
1917	H30	Submarine HMS H30 laid down
1941	Thorn	Submarine HMS Thorn launched
1943	Surf	Submarine HMS Surf completed
1904	HMS A1	Whist on exercise off the Isle of Wight HMS A1 was tasked with 'attacking' HMS Juno. The mock attack began in the early afternoon; HMS Juno had been sighted heading towards Portsmouth Harbour. First to attack were the Holland Boats, after which came A1's turn. As A1 closed in for the kill she was struck on the starboard side, near the conning tower, by the steam ship Berwick Castle, on route from Southampton to Hamburg. Unaware of the submarines in the area the master of the Berwick Castle reported that he believed he had been struck by a practice torpedo and continued his journey. It was not until A1 failed to return to harbour that the full scale of the disaster was known
1942	HMS Upholder	HMS Upholder torpedoes and sinks the Italian submarine Trichecoeast off Brindisi in the southern Adriatic.
1945	HMS Thrasher	HMS Thrasher sinks a Japanese sailing vessel with gunfire of the west coast of Burma.

SAB