On 9 October 1940 Triad (Lt.Cdr. George Stevenson Salt, RN) sailed from Malta to operate in the Gulf of Taranto, with orders to reach Alexandria on completion of her patrol and was never heard from again. Long believed to have been lost in a minefield, new evidence points to Triad having been the boat engaged and sunk on the night of 15 October by the Italian submarine Enrico Toti in position 38º16'N, 17º37'E.

Analysis of Triad's movements and Toti's action
Triad was directed to pass through position 35º10'N, 15º00'E, 50 nm SE of Valletta, then head for her initial billet, in position 38º36'N, 17º02'E, 25 nm east of Punta Stilo. Her patrol area was designated as a rectangle of 40 nm length whose western limit was 35 nm bearing 035° from position 38º24'N, 16º51'E.
Triad was ordered to leave her patrol area in the afternoon of 14 October and routed on the same line as Rainbow, so as to reach Alexandria at sunset of 20 October

At 0100 hrs of 15 October, the Italian submarine Enrico Toti (Lt.Cdr Bandino Bandini) sighted a large submarine 1,000 metres to port: both boats maneuvered into attack position but the British opened fire first, scoring 2 hits, one on the CT, the other on the bow. She also fired a torpedo which Bandini avoided by turning, then closed the enemy at best speed, firing with everything available. Soon, mg fire compelled the British gunners to abandon the exposed deck. As the British started to dive, Toti fired a torpedo & also scored 2 shell hits. The boat rose vertically then disappeared without survivors. The entire action had lasted less than 30 minutes

According to Toti's log, the action took place in position 38º16'N, 17º37'E, locating it 5 nm inside Triad's area and 5 nm outside the western limit of Rainbow. Since Rainbow had been ordered to leave the area on 13 October, she would have been gone 26-30 hrs before the action described above. Even at the modest speed of 6 kn, Rainbow would have been 200 nm away from the spot at the time of the action. It is therefore postulated that the only boat in Toti's vicinity was Triad, and she was the Italian boat's victim.

See Rainbow's entry for an examination of her movements and likely cause of loss.

Commanding officers:
Lt.Cdr. Ronald McClellan Powning Jonas, RN
2 April 1939 - 27 February 1940

Lt.Cdr. Eric Roland John Oddie, RN
27 February 1940 - 15 August 1940
Promoted to Cdr. on 30 June 1940
DSO awarded on 28 June 1940

Lt.Cdr. George Stevenson Salt, RN
15 August 1940 - 15 October 1940+