The , also called or was a type of the 1st class

submarine A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...

in the

Imperial Japanese Navy The Imperial Japanese Navy (IJN; Kyūjitai: Shinjitai: ' 'Navy of the Greater Japanese Empire', or ''Nippon Kaigun'', 'Japanese Navy') was the navy of the Empire of Japan from 1868 to 1945, when it was dissolved following Japan's surrender ...

serving during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

. The type name, was shortened to . The , also called was different from the ''I-361'' class, however since the ''I-373'' was a development form of the ''I-361'' class, this article describes both of them.

Construction

After the

Battle of Midway The Battle of Midway was a major naval battle in the Pacific Theater of World War II that took place on 4–7 June 1942, six months after Japan's attack on Pearl Harbor and one month after the Battle of the Coral Sea. The U.S. Navy under Adm ...

the IJN immediately planned a transport submarine. The type was based on the '' U 155 Deutschland''. Her duties were transportation of troops (110 men, 10 tons freight and two landing craft) in the areas where the enemy had air superiority. Later the demands for her were changed in sequence. The final demands were 65 tons in the hull and 25 tons on the upper deck (freight only). In the beginning the IJN did not intend to arm these boats with

torpedo A modern torpedo is an underwater ranged weapon launched above or below the water surface, self-propelled towards a target, and with an explosive warhead designed to detonate either on contact with or in proximity to the target. Historically, su ...

es. Later, after strong demands from the front commanders, it was decided to arm them with torpedoes for self-defense. The ''I-372'' class was designed as a tanker submarine based on the ''I-361'' class. They were not allowed to be loaded with torpedoes.

Service

In 1944, the submarines were tasked with transport missions between from mainland Japan to remote islands. They had little success and suffered great losses. Of the 13 submarines, only four survived the war.

Kaiten missions

In 1945, several submarines were converted to be ''

Kaiten were crewed torpedoes and suicide craft, used by the Imperial Japanese Navy in the final stages of World War II. History In recognition of the unfavorable progress of the war, towards the end of 1943 the Japanese high command considered s ...

'' mother ships and assigned to the suicide attack operations for the . Their deck guns were removed and fittings for five ''Kaiten''s were installed on their decks. * **Assigned to the on 24 May 1945, no success. * **Assigned to the Todoroki group on 28 May 1945, sank (or damaged) one motor ship on 15 June 1945. **Assigned to the on 8 August 1945, no success. * **Assigned to the Tamon group on 1 August 1945, no success. * **Assigned to the on 5 May 1945, damaged USS ''Gilligan'' on 27 May 1945. **Assigned to the Tamon group on 19 July 1945, no success. * **Assigned to the on 20 February 1945, no success. * **Assigned to the Chihaya group on 20 February 1945, no success. Image:Japanese submarine I-363.jpg, ''I-363'' in May or August 1945 Image:Japanese submarine I-367.jpg, ''I-367'' on 19 July 1945 Image:Japanese submarine I-370.jpg, ''I-370'' on 21 February 1945

Class variants

The ''Type-D'' submarines were divided into four classes: * * * * . The ''2968th vessel'' class boats were not built and remained only a design.

''I-361'' class

''I-372'' class

Project number S51B. She was going to become a lead ship of the ''Modified Type D'' submarines (''I-373'' class), at first. However, the IJN wanted a submarine as soon as possible. She was built as a tanker submarine according to revised ''I-361'' drawings.

''I-373'' class

Project number S51C. Improved model of the ''I-361'' class. Furthermore, the IJN was planned reinforced model of the ''I-373'' class,Project Number S60, also. However all of them were cancelled.

Footnotes

Bibliography

* * * *'', History of Pacific War Vol.17 I-Gō Submarines'',

Gakken is a Japanese publishing company founded in 1947 by Hideto Furuoka, which also produces educational toys. Their annual sales is reported at ¥ 90 billion ($789 million US). Gakken publishes educational books and magazines and produces other ...

(Japan), January 1998, *'', History of Pacific War Vol.36 Kairyū and Kaiten'',

(Japan), May 2002, *'', History of Pacific War Vol.62 Ships of The Imperial Japanese Forces'',

(Japan), January 2008, *'', History of Pacific War Vol.63 Documents of IJN submarines and USN submarines'',

(Japan), January 2008, *''The Maru Special, Japanese Naval Vessels No.43 Japanese Submarines III'', Ushio Shobō (Japan), September 1980, Book code 68343-43 *

Senshi Sōsho The , also called the , is the official military history of Imperial Japan's involvement in the Pacific War from 1937 to 1945. The task of compiling the official account of the Japanese involvement in World War II began in October 1955 with the op ...

Vol.88, ''Naval armaments and war preparation (2), "And after the outbreak of war"'', Asagumo Simbun (Japan), October 1975