Type B1 submarine


Type B1 submarine I-25
Class overview
Operators: Imperial Japanese Navy
Completed: I-15, I-17, I-19, I-21, I-23, I-25, I-26, I-27, I-28, I-29, I-30, I-31, I-32, I-33, I-34, I-35, I-36, I-37, I-38, I-39
General characteristics
Displacement: 2,584 tons surfaced
3,654 tons submerged
Length: 356.5 ft (108.7 m)
Beam: 30.5 ft (9.3 m)
Draft: 16.8 ft (5.1 m)
Propulsion: 2 diesels: 12,400 hp (9,200 kW)
Electric motors: 2,000 hp (1,500 kW)
Speed: 23.5 knots (44 km/h) surfaced
8 knots (15 km/h) submerged
Range: 14,000 nautical miles (26,000 km) at 16 knots (30 km/h)
Test depth: 100 m (330 ft)
Complement: 94 officers and men
Armament:

6 × 533 mm forward torpedo tubes
17 torpedoes

1 × 140 mm 50 calibre gun
Aircraft carried: 1 Yokosuka E14Y seaplane

The Type B1 submarine (also known as the I-15 series) were the most numerous submarine class of the Imperial Japanese Navy during World War II. In total 20 were built, starting with I-15, which gave the series their alternative name.

These submarines were fast, had a very long range, and carried a single seaplane, located in a hangar in front of the conning tower, and launched by a catapult. Late in the war, some of the submarines had their aircraft hangar removed, to replace it with a 14 cm gun. In 1944, the I-36 and I-37 were modified so that they could carry four Kaiten manned torpedoes, with I-36 later being further modified to carry six.

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.

References

  1. ^ a b Boyd, Carl; Akihiko Yoshida (2002). The Japanese Submarine Force and World War II. Naval Institute Press. ISBN 1557500150. 
  2. ^ report of the sinking of I-35, Department of Defence (Australia), undated World War II, accessed 24 April 2010