HMS Triton N15

HMS Triton (N15) was a British T‑class submarine, the lead boat of her class, serving from 1938 until her loss in 1940. She is best known for two major events: accidentally sinking HMS Oxley at the start of WWII, and later being lost with all hands in the Adriatic. She was a Royal Navy diesel‑electric submarine, built by Vickers‑Armstrongs at Barrow‑in‑Furness. She was the first of the Triton-class (T‑class) boats, designed for long-range patrols in European waters. 

Key facts

• Laid down: 28 August 1936
• Launched: 5 October 1937
• Commissioned: 9 November 1938
• Pennant number: N15
• Complement: 59
• Fate: Lost 18 December 1940, likely to a mine in the Adriatic 

Specifications

• Class: T‑class submarine
• Length: 275 ft (84 m)
• Beam: 26 ft 6 in (8.08 m)
• Draught: 16.3 ft (5.0 m)
• Displacement: 1,090 tons surfaced / 1,575 tons submerged
• Speed: 15.25 knots surfaced / 9 knots submerged
• Range: 4,500 nautical miles at 11 knots
• Armament:
  • 6 internal forward 21‑inch torpedo tubes
  • 4 external forward tubes
  • 6 reload torpedoes
  • 1 × 4‑inch deck gun

The Sinking of HMS Oxley (10 September 1939)

Triton fired on a submarine that failed to respond to recognition signals. Believing it to be a German U‑boat, she launched torpedoes—only to discover it was HMS Oxley, another British submarine. Two survivors were rescued; the incident was ruled a tragic wartime mistake. 

🌊 Final Patrol and Loss

Triton departed Malta on 28 November 1940 for a patrol in the southern Adriatic. She never returned. Evidence suggests she struck a mine in the Otranto Strait around 18 December 1940, with all 59 crew lost. 

📘 Commanding Officers