HMS Rainbow was the lead boat of the Rainbow-class submarine of the Royal Navy. She was built at Chatham Dockyard, launched on 14 May 1930, and commissioned on 18 January 1932.
Specifications
- Class: Rainbow-class submarine (R Class)
- Length: 287 ft (87 m)
- Displacement: 1,763 tons surfaced; 2,030 tons submerged
- Crew: 53 to 56 officers and ratings
- Armament:
- 8 × 21-inch torpedo tubes
- 1 × 4.7-inch deck gun
Service
Rainbow was designed for long-range operations in the Far East and spent much of the 1930s on the China Station, operating from Hong Kong and Singapore.
In 1940 she was transferred to the Mediterranean and joined the 1st Submarine Flotilla based at Alexandria.
Loss and the "Enrico Toti" Mystery
For many years it was widely believed that Rainbow had been sunk on 15 October 1940 by the Italian submarine Enrico Toti. Later research showed that the submarine sunk by Enrico Toti was almost certainly HMS Triad, not Rainbow.
The current accepted account is that Rainbow was lost much earlier, on 4 October 1940. Evidence from Italian convoy records indicates she was accidentally rammed by the Italian merchant ship Antonietta Costa while submerged about 60 nautical miles east-northeast of Bari in the Adriatic Sea. The merchant ship reported striking a large underwater object, immediately followed by a major underwater explosion.
Rainbow had sailed from Alexandria on 23 September 1940 and was never heard from again. She was carrying her full complement of officers and men.
Connection to HMS Triad
The confusion between Rainbow and Triad persisted for decades. Post-war analysis of Italian and British records established that:
- HMS Rainbow was almost certainly lost in a collision with Antonietta Costa on 4 October 1940.
- HMS Triad was almost certainly the submarine sunk by Enrico Toti on 15 October 1940.
This correction is one of the more interesting submarine-detection mysteries of the Mediterranean war
