Rainbow-class submarine
The Rainbow-class submarine or R class was a quartet of patrol submarines built for the Royal Navy in the early 1930s.
Design and description
The Rainbow-class submarines were designed as improved versions of the Parthian class and were intended for long-range operations in the Far East. The submarines had a length of overall, a beam of and a mean draft of. They displaced on the surface and submerged. The Rainbow-class submarines had a crew of 56 officers and ratings. They had a diving depth of.For surface running, the boats were powered by two diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a electric motor. They could reach on the surface and underwater. On the surface, the boats had a range of at and at submerged.
The boats were armed with six 21-inch torpedo tubes in the bow and two more in the stern. They carried six reload torpedoes for a grand total of fourteen torpedoes. They were also armed with a QF 4.7-inch Mark IX deck gun.
Boats
Six boats were planned, but economic considerations resulted in the cancellation of the projected boats HMS Royalist and HMS Rupert.| Name | Builder | Launched | Fate |
| Chatham Dockyard | 14 May 1930 | Sunk 4 October 1940 in collision with the Italian merchant ship Antonietta Costa | |
| Vickers, Barrow in Furness | 11 June 1930 | Sunk 18 April 1943 by mines near Barletta, Apulia, Italy | |
| Vickers, Barrow in Furness | 11 June 1930 | Sunk 6 December 1940 by mines near Taranto, Apulia, Italy | |
| Vickers, Barrow in Furness | 11 June 1930 | Scrapped 1946 |
It is often stated that the sank HMS Rainbow. However, the submarine Enrico Toti sank was.