The Japanese submarine I-31 was one of 20 Type B cruiser submarines of the B1 sub-class built for the Imperial Japanese Navy (IJN) during the 1940s.
The Type B submarines were derived from the earlier KD6 sub-class of the and were equipped with an aircraft to enhance their scouting ability. They displaced 25890NaN0 surfaced and 36540NaN0 submerged. The submarines were 108.7m (356.6feet) long, had a beam of 9.3m (30.5feet) and a draft of 5.1m (16.7feet). They had a diving depth of 100m (300feet).[1]
For surface running, the boats were powered by two 62000NaN0 diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 1000hp electric motor. They could reach 23.6kn on the surface and underwater.[2] On the surface, the B1s had a range of 14000nmi at ; submerged, they had a range of 96nmi at .
The boats were armed with six internal bow 53.3cm (21inches) torpedo tubes and carried a total of 17 torpedoes. They were also armed with a single 140mm/40 deck gun and two single mounts for 250NaN0 Type 96 anti-aircraft guns.[3] In the Type Bs, the aircraft hangar was faired into the base of the conning tower. A single catapult was positioned on the forward deck.[3]
In November 1942, I-31 was spotted doing reconnaissance with its seaplane off Suva, Fiji.[4]
On 12 May 1943 I-31 attacked the USS Pennsylvania and the USS Santa Fe (CL-60) with torpedoes nine miles northeast of Holtz Bay, all missed.[5] On 12 May 1943, near Holtz Bay, Attu, her periscope was sighted by American destroyers, and, who immediately opened fire. I-31 dove quickly but not before Edwards scored hits. The destroyers quickly made sonar contact and began a series of depth charge attacks until, after surviving for 10 hours, she was sunk by Frazier on 13 May.[6] [7] [8]
Web site: USS Amberjack: Lost around 16 February 1943. The USS Flier Project. 18 June 2015. 19 June 2015. https://web.archive.org/web/20150619043552/http://www.ussflierproject.com/2014/02/uss-amberjack-lost-around-16-february-1943/. dead. 52.542°N 172.177°W