Type B1 submarine explained

The, also called was the first group of boats of the Type B cruiser submarines built for the Imperial Japanese Navy (IJN) during the 1940s. In total 20 were built, starting with, which gave the series their alternative name.

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 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. Late in the war, some of the submarines had their aircraft hangar removed, to replace it with an additional 14 cm gun. In 1944, I-36 and I-37 had their aircraft hangar and catapult removed so that they could carry four Kaiten manned torpedoes, with I-36 later being further modified to carry six.[3]

Service

The series was rather successful, especially at the beginning of the war.

Losses

Altogether the Type B submarines (B1, B2, and B3 combined) are credited with sinking 56 merchant ships for a total of 372,730 tonnes, about 35% of all merchant shipping sunk by Japanese submarines during the war.

All B1 type submarines were lost during the conflict, except for , which was scuttled off Gotō Islands by the US Navy on 1 April 1946.

See also

References

Notes and References

  1. Bagnasco, p. 189
  2. Chesneau, p. 200
  3. Carpenter & Dorr, p. 102
  4. Book: Cressman, Robert . The official chronology of the U.S. Navy in World War II . Chapter V: 1943 . http://www.ibiblio.org/hyperwar/USN/USN-Chron/USN-Chron-1943.html . Annapolis, Maryland . Naval Institute Press . 2000 . 978-1-55750-149-3 . 41977179 . 2012-09-14 . registration .
  5. Book: Boyd, Carl . Akihiko Yoshida . The Japanese Submarine Force and World War II . Naval Institute Press . 2002 . 1-55750-015-0.
  6. Book: Rohwer. Jürgen. Hümmelchen. Gerhard. Chronology of the War at Sea, 1939–1945: the Naval History of World War Two. 2005. Naval Institute Press. Annapolis, Md.. 9781591141198. 289. 3. rev..
  7. http://www.defence.gov.au/sydneyii/EXP/EXP.001.0065.pdf report of the sinking of I-35