Type B1 submarine

I-25
Class overview
Name: B1 class
Operators: Imperial Japanese Navy
Preceded by: Type J3 submarine
Succeeded by: Type B2 submarine
Completed: 18
Lost: 17
Scrapped: 1
General characteristics
Class and type: Cruiser submarine
Displacement:
  • 2,631 tonnes (2,589 long tons) surfaced
  • 3,713 tonnes (3,654 long tons) submerged
Length: 108.7 m (356 ft 8 in) overall
Beam: 9.3 m (30 ft 6 in)
Draft: 5.1 m (16 ft 9 in)
Installed power:
Propulsion:
Speed:
  • 23.5 knots (43.5 km/h; 27.0 mph) surfaced
  • 8 knots (15 km/h; 9.2 mph) submerged
Range:
  • 14,000 nmi (26,000 km; 16,000 mi) at 16 knots (30 km/h; 18 mph) surfaced
  • 96 nmi (178 km; 110 mi) at 3 knots (5.6 km/h; 3.5 mph) submerged
Test depth: 100 m (330 ft)
Crew: 94
Armament:
Aircraft carried: 1 × floatplane
Aviation facilities: 1 × catapult

The Type B1 submarine (巡潜乙型潜水艦 Junsen Otu-gata sensuikan, "Cruiser submarine type B"), also called I-15-class submarine (伊一五型潜水艦 I-jū-go-gata sensuikan) 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 I-15, which gave the series their alternative name.

Design and description

The Type B submarines were derived from the earlier KD6 sub-class of the Kaidai class and were equipped with an aircraft to enhance their scouting ability. They displaced 2,631 tonnes (2,589 long tons) surfaced and 3,713 tonnes (3,654 long tons) submerged. The submarines were 108.7 meters (356 ft 8 in) long, had a beam of 9.3 meters (30 ft 6 in) and a draft of 5.1 meters (16 ft 9 in). They had a diving depth of 100 meters (330 ft).[1]

For surface running, the boats were powered by two 6,200-brake-horsepower (4,623 kW) diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 1,000-horsepower (746 kW) electric motor. They could reach 23.6 knots (43.7 km/h; 27.2 mph) on the surface and 8 knots (15 km/h; 9.2 mph) underwater.[2] On the surface, the B1s had a range of 14,000 nautical miles (26,000 km; 16,000 mi) at 16 knots (30 km/h; 18 mph); submerged, they had a range of 96 nmi (178 km; 110 mi) at 3 knots (5.6 km/h; 3.5 mph).[3]

The boats were armed with six internal bow 53.3 cm (21.0 in) torpedo tubes and carried a total of 17 torpedoes. They were also armed with a single 14 cm (5.5 in) deck gun and two single mounts for 25 mm (1 in) 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 replaced, 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 I-36, which was scuttled off Gotō Islands by the US Navy on 1 April 1946.

See also

Notes

  1. Bagnasco, p. 189
  2. Chesneau, p. 200
  3. 1 2 3 Carpenter & Dorr, p. 102
  4. Cressman, Robert (2000). "Chapter V: 1943". The official chronology of the U.S. Navy in World War II. Annapolis, Maryland: Naval Institute Press. ISBN 978-1-55750-149-3. OCLC 41977179. Retrieved 2012-09-14.
  5. 1 2 Boyd, Carl; Akihiko Yoshida (2002). The Japanese Submarine Force and World War II. Naval Institute Press. ISBN 1-55750-015-0.
  6. Rohwer, Jürgen; Hümmelchen, Gerhard (2005). Chronology of the War at Sea : 1939-1945 : the Naval History of World War II (3. rev. ed.). Annapolis, Md.: Naval Institute Press. p. 289. ISBN 9781591141198.
  7. report of the sinking of I-35, Department of Defence (Australia), undated World War II, accessed 24 April 2010

References

This article is issued from Wikipedia - version of the Saturday, March 26, 2016. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.