HMS Rainbow was a Rainbow-class submarine constructed for the Royal Navy during the 1930s, embodying an advanced design aimed at long-range operations, particularly in the Far East. The vessel measured 287 feet 2 inches (87.5 meters) in length, with a beam of 29 feet 10 inches (9.1 meters) and a mean draft of 13 feet 10 inches (4.2 meters). It displaced 1,772 long tons (1,800 tons) on the surface and 2,030 long tons (2,060 tons) when submerged. The submarine was crewed by 56 officers and ratings and was capable of diving to depths of 300 feet (91.4 meters). Powered by two 2,200-brake-horsepower diesel engines for surface travel, each driving a propeller shaft, HMS Rainbow could reach a maximum speed of 17.5 knots (32.4 km/h; 20.1 mph) on the surface. When submerged, it relied on electric motors producing 660 horsepower, allowing a speed of 9 knots (17 km/h; 10 mph). Its operational range was notable, with a distance of 7,050 nautical miles (13,060 km; 8,110 miles) at 9.2 knots when on the surface, and a submerged endurance of 62 nautical miles (115 km; 71 miles) at 4 knots. Armament comprised six 21-inch (530 mm) torpedo tubes in the bow, two in the stern, and six reload torpedoes, totaling fourteen torpedoes. Additionally, HMS Rainbow was equipped with a QF 4.7-inch (120 mm) Mark IX deck gun for surface engagements. HMS Rainbow's service record included an incident in 1932 when she ran aground in the English Channel off Ventnor, Isle of Wight, but was refloated later the same day. During World War II, she served in the Far East until 1940, after which she transferred to the Mediterranean. In September 1940, she departed for a patrol off Calabria, but was lost after 25 September 1940, believed to have been sunk in a collision with the Italian merchant ship Antonietta Costa on 4 October 1940. The sinking was attributed to a submerged collision, coinciding with reports of an explosion and the ship's sinking while in convoy. For many years, it was mistakenly thought that the Italian submarine Enrico Toti had sunk Rainbow, but later investigations clarified that HMS Triad was responsible for sinking Toti.

This description has been generated using GPT-4.1-NANO based on the Vessel's wikidata information and then modified by ShipIndex.org staff.