The was a transport submarine of the Imperial Japanese Navy

Imperial Japanese Navy

The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

 (IJN), serving during late World War II

World War II

World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

. The IJN planned to build 12 boats, but only 10 vessels were completed by the end of the war. The IJN called these submarines . Several boats were converted to tankers or mother ships for the midget submarines.

Planned construction

Project number S57. In February 1944, the IJN planned a small-size transport submarine, the IJA

Imperial Japanese Army

-Foundation:During the Meiji Restoration, the military forces loyal to the Emperor were samurai drawn primarily from the loyalist feudal domains of Satsuma and Chōshū...

 planned the Maru Yu.

Boats

Boat #	Name	Builder	Laid down	Launched	Completed	Decommissioned	Fate
4601	Ha-101	Kawasaki-Senshū Shipyard, Kawasaki-Kōbe Shipyard	08-06-1944	22-08-1944	22-11-1944	15-09-1945	Converted to a tanker submarine in June 1945; scuttled off Simizu City Shimizu-ku, Shizuoka is one of three wards of the city of Shizuoka, in Shizuoka Prefecture, Japan, located in the eastern part of the city.-Geography:Shimizu is located on the coast of Suruga Bay of the Pacific Ocean and covers a wide area from a coastal plain to the hills...  October 1945
4602	Ha-102	Kawasaki-Senshū Shipyard, Kawasaki-Kōbe Shipyard	08-06-1944	22-08-1944	06-12-1944	15-09-1945	Converted to a tanker submarine in June 1945; scuttled off Simizu City October 1945
4603	Ha-103	Kawasaki-Senshū Shipyard, Kawasaki-Kōbe Shipyard	29-06-1944	21-10-1944	03-02-1945	30-11-1945	Converted to a radar picket submarine April 1945; re-converted to a tanker submarine in June 1945; scuttled off the Gotō Islands Goto Islands The are Japanese islands in the East China Sea, off the western coast of Kyūshū. The islands are a part of Nagasaki Prefecture.- Geography :There are 140 islands in total, including five main islands:,,,, and....  01-04-1946
4604	Ha-104	Kawasaki-Kōbe Shipyard	01-07-1944	30-09-1944	01-12-1944	15-09-1945	Converted to a tanker submarine June 1945; scuttled off Simizu City October 1945
4605	Ha-105	Kawasaki-Senshū Shipyard, Kawasaki-Kōbe Shipyard	29-06-1944	31-10-1944	19-02-1945	30-11-1945	Converted to a radar picket submarine in March or April 1945; re-converted to a tanker submarine in June 1945; scuttled off the Gotō Islands 01-04-1946
4606	Ha-106	Mitsubishi-Kōbe Shipyard	01-07-1944	30-10-1944	15-12-1944	30-11-1945	Converted to Kōryū mother ship June 1945; scuttled off the Gotō Islands 01-04-1946
4607	Ha-107	Mitsubishi-Kōbe Shipyard	01-08-1944	20-12-1944	20-03-1945	30-11-1945	Converted to Kōryū mother ship June 1945; scuttled off the Gotō Islands 01-04-1946
4608	Ha-108	Kawasaki-Senshū Shipyard, Kawasaki-Kōbe Shipyard	05-09-1944	28-12-1944	06-05-1945	30-11-1945	Converted to Kōryū mother ship June 1945; scuttled off the Gotō Islands 01-04-1946
4609	Ha-109	Mitsubishi-Kōbe Shipyard	01-08-1944	10-01-1945	10-03-1945	30-11-1945	Converted to Kairyū Kairyu class submarine The was a class of midget submarines of the Imperial Japanese Navy, designed in 1943–1944, and produced from the beginning of 1945. These submarines were meant to meet the invading American naval forces upon their anticipated approach of Tokyo.-History:... 's tender July 1945; scuttled off the Gotō Islands 01-04-1946
4610	Ha-110	Kawasaki-Senshū Shipyard, Kawasaki-Kōbe Shipyard	05-09-1944	12-01-1945			95 % complete; scuttled in the Kii Channel Kii Channel The is a strait separating the Japanese Home Islands of Honshū and Shikoku. This channel connects the Inland Sea with the Pacific Ocean....  15-04-1946
4611	Ha-111	Mitsubishi-Kōbe Shipyard	16-11-1944	02-03-1945	13-07-1945	30-11-1945	scuttled off the Gotō Islands 01-04-1946
4612	Ha-112	Mitsubishi-Kōbe Shipyard	16-11-1944	15-04-1945			95 % complete; scuttled in the Kii Channel 15-04-1946