The was a transport submarine built for the Imperial Japanese Navy (IJN) during World War II. The IJN planned to build 12 boats, but only 10 vessels were completed by the end of the war. The IJN called these submarines . The type name was shortened to .The read as "Sen'yu-Shō", but the read as "Sen'yu-Ko-gata" in Japanese.

Several boats were converted to tankers or mother ships for midget submarines.

Design and description The Ha-101-class submarines were designed as small, cheap transport submarines to resupply isolated island garrisons. They displaced surfaced and submerged. The submarines were long, had a beam of and a draft of . They were designed to carry of cargo.Carpenter & Dorr, p. 140

For surface running, the boats were powered by a single diesel engine that drove one propeller shaft. When submerged the propeller was driven by a electric motor. They could reach on the surface and underwater.Chesneau, p. 204 On the surface, the Ha-101s had a range of at ; submerged, they had a range of at . The boats were armed a single mount for a Type 96 anti-aircraft gun.Bagnasco, p. 195

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

Boats Boat # Name Builder Laid down Launched Completed Decommissioned Fate 4601 . The same shall apply hereinafter. 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;Senshi Sōsho Vol.88 (1975), p.272–273 scuttled off Shimizu City October 1945 4602 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 Shimizu City October 1945 4603 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 01-04-1946 4604 Kawasaki-Kōbe Shipyard 01-07-1944 30-09-1944 01-12-1944 15-09-1945 Converted to a tanker submarine June 1945; scuttled off Shimizu City October 1945 4605 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 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 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 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 Mitsubishi-Kōbe Shipyard 01-08-1944 10-01-1945 10-03-1945 30-11-1945 Converted to '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 15-04-1946 4611 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

See also Type 4 Ka-Tsu Imperial Japanese Army Railways and Shipping Section Type 3 submergence transport vehicle, Yu II type

Footnotes

Bibliography

, History of Pacific War Extra, "Perfect guide, The submarines of the Imperial Japanese Forces", Gakken (Japan), March 2005, Ships of the World special issue Vol.37, History of Japanese Submarines, , (Japan), August 1993 The Maru Special, Japanese Naval Vessels No.43 Japanese Submarines III, Ushio Shobō (Japan), September 1980, Book code 68343-43 The Maru Special, Japanese Naval Vessels No.132 Japanese Submarines I "Revised edition", Ushio Shobō (Japan), February 1988, Book code 68344-36 Senshi Sōsho Vol.88, Naval armaments and war preparation (2), "And after the outbreak of war", Asagumo Simbun (Japan), October 1975