Japanese submarine I-31
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. Design and description 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 surfaced and submerged. The submarines were long, had a beam of and a draft of . 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 B1s had a range of at ; submerged, they had a range of at . The boats were armed with six internal bow torpedo tubes and carried a total of 17 torpedoes. They were also armed with a single /40 deck gun and two single mounts for Type 96 anti-aircraft guns. 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. Career In November 1942, I-31 was spotted doing reconnaissance with its seaplane off Suva, Fiji. 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. 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. Notes References External links 1941 ships 1943 in Alaska World War II submarines of Japan Japanese submarines lost during World War II Ships built by Yokosuka Naval Arsenal Ships of the Aleutian Islands campaign Shipwrecks of the Alaska coast Type B1 submarines World War II shipwrecks in the Pacific Ocean Maritime incidents in May 1943