HMS Regulus (N88)

HMS Regulus (N88) was a Rainbow-class submarine built for the Royal Navy during the 1930s.

Design and description
The Rainbow-class submarines were designed as improved versions of the Parthian-class submarine and were intended for long-range operations in the Far East. The submarines had a length of 287 ft overall, a beam of 29 ft and a mean draft of 13 ft. They displaced 1772 LT on the surface and 2030 LT submerged. The Rainbow-class submarines had a crew of 56 officers and ratings. They had a diving depth of 300 ft.

For surface running, the boats were powered by two 2200 bhp diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 660 hp electric motor. They could reach 17.5 kn on the surface and 9 kn underwater. On the surface, the boats had a range of 7050 nmi at 9.2 kn and 62 nmi at 4 kn submerged.

The boats were armed with six 21 in 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 (120 mm) Mark IX deck gun.

Construction and career
Regulus was laid down by Vickers-Armstrong at Barrow-in-Furness and launched in 1930. Before Second World War she was stationed with Submarine Flotilla #4 on the China station, based out of Hong Kong.

In October 1939 Regulus conducted intelligence-gathering operations in the mouth of the Bungo Strait, off the coast of Japan. It covertly observed Imperial Japanese Navy fleet exercises, including JAPANESE AIRCRAFT CARRIER Ryujo and a brand new Japanese aircraft carrier, likely JAPANESE AIRCRAFT CARRIER Hiryu. It had also entered Shibushi Bay and Osaka Bay via the Kitan Strait, producing photographic intelligence.

Regulus (Lt.Cdr. Frederick Basil Currie, RN) left Alexandria to patrol in the southern Adriatic on 23 November 1940. She was lost with her entire crew on 6 December 1940 whilst on patrol off Taranto, Italy. In all probability she hit a mine.