Type B submarine

The Cruiser submarine Type-B was a class of submarine in the Imperial Japanese Navy which served during World War II. The Type-B submarines were similar to the Type-A apart from not having the headquarters installation.

Class variants

The Type-B submarines were divided into four classes:Type-B Type-B Mod.1Type-B Mod.2V22A Type. The 5115th vessel-class submarines were not built and remained a design only.

''Type-B'' (''I-15'' class)

[Image:I-15.jpg|thumb|I-15 on 15 September 1940]
Project number S37. Twenty boats were built between 1937 and 1944 under the Maru 3 Programme and Maru 4 Programme.

Boat No.	Boat	Builder	Laid down	Launched	Completed	Fate
37		Kure Naval Arsenal	25 January 1938	7 March 1939	30 September 1940	Sunk by near San Cristóbal on 10 November 1942.
38		Yokosuka Naval Arsenal	18 April 1938	19 July 1939	24 January 1941	Sunk by and maritime patrol aircraft at Nouméa on 19 August 1943.
39		Mitsubishi, Kōbe Shipyard	15 March 1938	16 September 1939	28 April 1941	Sunk by in the Gilbert Islands on 25 November 1943.
40		Kawasaki, Kōbe Shipyard	7 January 1939	24 February 1940	15 July 1941	Missing near Tarawa after 27 November 1943. Possibly sunk by aircraft from on 29 November 1943.
41		Yokosuka Naval Arsenal	8 December 1938	24 November 1939	27 September 1941	Missing near the Hawaiian Islands after 24 February 1942, most likely due to a diving accident.
42		Mitsubishi, Kōbe Shipyard	3 February 1939	8 June 1940	15 October 1941	Missing near Espiritu Santo after 23 August 1943. Possibly sunk by on 25 August 1943.
43						The dummy for the naval budget of the.
139		Kure Naval Arsenal	7 June 1939	10 April 1940	6 November 1941	Missing east of the Philippines after 25 October 1944. Possibly sunk by on 26 October 1944.
140		Sasebo Naval Arsenal	5 July 1939	6 June 1940	24 February 1942	Sunk by and in the Maldives at on 12 February 1944.
141		Mitsubishi, Kōbe Shipyard	25 September 1939	17 December 1940	6 February 1942	Sunk by north of Rabaul at on 17 May 1942.
142		Yokosuka Naval Arsenal	20 September 1939	29 September 1940	27 February 1942	Sunk by south of Sabtang Island at on 26 July 1944.
143		Kure Naval Arsenal	7 June 1939	17 September 1940	28 February 1942	Sunk by a British mine at Singapore on 13 October 1942. Raised and scrapped between August 1959 and February 1960.
144		Yokosuka Naval Arsenal	6 December 1939	13 March 1941	30 May 1942	Sunk by at Attu Island on 13 May 1943.
145		Sasebo Naval Arsenal	20 January 1940	17 December 1940	26 April 1942	Sunk by and USS PC-1135 northeast of Wotje Atoll on 24 March 1943.
146		Mitsubishi, Kōbe Shipyard	21 February 1940	1 May 1941	10 June 1942	Lost in an accident at Truk on 26 September 1942. Salvaged and repaired starting 29 December 1943. Later, lost in another accident at Iyo Nada on 13 June 1944. Salvaged and scrapped starting 28 June 1953.
147		Sasebo Naval Arsenal	9 January 1941	24 September 1941	31 August 1942	Sunk by at Penang Island on 13 November 1943. Salvaged on 4 December 1962.
148		Mitsubishi, Kōbe Shipyard	2 September 1940	24 September 1941	31 August 1942	Sunk by and south of Tarawa on 22 November 1943.
149		Yokosuka Naval Arsenal	4 December 1940	1 November 1941	30 September 1942	Converted to a Kaiten mother ship on 1 September 1944. Decommissioned on 30 November 1945, blown up off the Gotō Islands on 1 April 1946 as part of Operation Road's End.
150		Kure Naval Arsenal	7 December 1940	22 October 1941	10 March 1943	Converted to a Kaiten mother ship on 9 September 1944. Sunk by and north of Palau, on 19 November 1944.
151		Sasebo Naval Arsenal	19 June 1941	15 April 1942	31 January 1943	Sunk by east of Luzon on 13 November 1944.
152		Sasebo Naval Arsenal	19 June 1941	15 April 1942	22 April 1943	Sunk by west of Makin at on 16 November 1943.
153						The dummy for the naval budget of the Yamato-class battleships

''Type-B Mod.1'' (''I-40'' class)

[Image:Japanese submarine I-45 in 1943.jpg|thumb|I-45 in 1943]
Project number S37B. Six boats were planned under the Maru Kyū Programme, all boats were completed. On the outside this class looked the same as the I-15 class; however, they were built from high-tensile strength steel and equipped with diesel engines of a simpler design.

Boat No.	Boat	Builder	Laid down	Launched	Completed	Fate
370		Kure Naval Arsenal	18 March 1942	10 November 1942	31 July 1943	Missing after 22 November 1943.
371		Kure Naval Arsenal	18 March 1942	10 November 1942	18 September 1943	Sunk by east of the Philippines at on 18 November 1944.
372		Kure Naval Arsenal	18 March 1942	10 November 1942	3 November 1943	Sunk by southwest of Palau at on 23 March 1944.
373		Sasebo Naval Arsenal	27 April 1942	25 October 1942	5 November 1943	After completion, converted to a carrier for a Daihatsu-class landing barge. Sunk by north of Truk at on 15 February 1944.
374		Yokosuka Naval Arsenal	11 June 1942	5 March 1943	31 January 1944	Converted to a Kaiten mother ship on 22 October 1944. Sunk by an aircraft from southeast of Okinawa at on 29 April 1945.
375		Sasebo Naval Arsenal	15 July 1942	6 March 1943	28 December 1943	Sunk by east of the Philippines on 29 October 1944.

''Type-B Mod.2'' (''I-54'' class)

[Image:Japanese submarine I-54 in 1944.jpg|thumb|I-54 in 1944]
Project number S37C. Twenty-one boats were planned under the Maru Kyū Programme and Kai-Maru 5 Programme. Eighteen boats were cancelled in late 1943, because the IJN was setting the as 1945's main submarines.
Boats in class
Boat No. Boat Builder Laid down Launched Completed Results Fate'
627 Yokosuka Naval Arsenal 1 July 1942 4 May 1943 31 March 1944 Damaged on 25-10-1944 Sunk east of Leyte by and on 28 October 1944.
629 Yokosuka Naval Arsenal 29 September 1942 30 June 1943 8 June 1944 Damaged USS LST-695 on 24 October 1944.
Damaged on 25 October 1944. Conversion to a Kaiten mother ship began in early October 1943 and completed in November 1944. Sunk by,,, and aircraft from east of Okinawa at on 18 April 1945.
631 Yokosuka Naval Arsenal 26 December 1942 9 October 1943 7 September 1944 Sank SS Wild Hunter on 28 July 1945, possibly by Kaiten
Sank on 30 July 1945
Damaged on 12 August 1945 by Kaiten Converted to a Kaiten mother ship before completion. Decommissioned on 30 November 1945, scuttled off the Gotō Islands on 1 April 1946 as part of Operation Road's End. Wreck found in 2017.
633 - 636 Cancelled in 1943
5101 - 5114 Cancelled in 1943

''V22A Type''
Project number S49A. Eighteen boats were planned under the Kai-Maru 5 Programme. However, all boats were cancelled in late 1943, because the IJN concentrated on production of Type-E submarine from 1945.
Boats in class
Boat No. Boat Builder Laid down Launched Completed Fate
5115 - 5132 Cancelled in 1943