Ro-100-class submarine
The Ro-100-class submarine was a group of medium-sized coastal submarines built for the Imperial Japanese Navy during World War II. The IJN official designation for this class was Ko Type submarine or Senshō Type submarine. The type name, was shortened to Sensuikan Ko-gata.
Design and description
In 1940, the IJN designed a point-defence coastal submarine because they wanted to save their larger submarines for fleet battles. The Ro-100 class was derived from the preceding Kaichū type. They displaced surfaced and submerged. The submarines were long, had a beam of and a draft of. They had a double hull and a diving depth of.For surface running, the boats were powered by two diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a electric motor. They could reach on the surface and underwater. On the surface, the Ro-100s had a range of at ; submerged, they had a range of at.
The boats were armed with four internal bow torpedo tubes and carried a total of eight torpedoes. They were also armed with two single mounts for Type 96 anti-aircraft guns or a single 8 cm/40 3rd Year Type naval gun| L/40 AA gun.
Boats
18 boats were built in 1941-1944 under the Maru Rin Programme and the Maru Kyū Programme.| Boat # | Name | Builder | Laid down | Launched | Completed | Results | Fate |
| 210 | Kure Naval Arsenal | 1941-06-30 | 1941-06-12 | 1942-08-23 | Sunk by naval mine off Bougainville Island 1943-11-25. | ||
| 211 | Kawasaki-Kōbe Shipyard | 1941-09-30 | 1942-04-17 | 1942-10-31 | Sunk by and PBY southeast of San Cristobal 1943-09-15. | ||
| 212 | Kawasaki-Kōbe Shipyard | 1941-09-30 | 1942-04-17 | 1942-11-17 | Disappeared south of Rabi after 1943-05-09. | ||
| 213 | Kure Naval Arsenal | 1941-06-30 | 1941-12-06 | 1942-10-21 | Sank 1943-06-23 Sank 1943-06-23 | Disappeared in the Solomon Islands after 1943-07-28, possibly sunk by a mine or a PT boat. | |
| 214 | Kawasaki-Kōbe Shipyard | 1941-11-19 | 1942-07-11 | 1943-02-25 | Sunk by north of the Admiralty Islands 1944-05-23. | ||
| 215 | Kawasaki-Kōbe Shipyard | 1941-11-19 | 1942-07-11 | 1943-03-05 | Sunk by north of the Admiralty Islands 1944-05-31. | ||
| 216 | Kure Naval Arsenal | 1941-12-17 | 1942-05-30 | 1942-12-26 | Sank 1943-07-11 | Sunk by north of the Admiralty Islands 1944-05-22. | |
| 217 | Kure Naval Arsenal | 1941-12-17 | 1942-05-30 | 1942-10-26 | Sunk by east of Kolombangara 1943-07-21. | ||
| 218 | Kawasaki-Kōbe Shipyard | 1942-04-20 | 1942-10-26 | 1943-04-20 | Sank 1943-10-03 | Sunk by north of the Admiralty Islands 1944-05-26. | |
| 400 | Kawasaki-Kōbe Shipyard | 1942-04-20 | 1942-10-26 | 1943-04-29 | Sunk by south of Okinawa Island 1945-04-25. | ||
| 401 | Kawasaki-Kōbe Shipyard | 1942-08-20 | 1943-01-26 | 1943-07-06 | Sunk by, and in the Bay of Bengal 1944-02-12. | ||
| 402 | Kawasaki-Kōbe Shipyard | 1942-08-20 | 1943-01-26 | 1943-07-10 | Sank RMS Peshawar 1943-12-23 | Sunk by north of the Admiralty Islands 1944-06-10. | |
| 403 | Kawasaki-Senshū Shipyard | 1942-06-20 | 1943-03-25 | 1943-09-14 | Sunk by in the Luzon Strait 1945-02-11. | ||
| 404 | Kawasaki-Senshū Shipyard | 1942-07-11 | 1943-04-24 | 1943-10-12 | Sunk by in the Luzon Strait 1945-02-12. | ||
| 405 | Kawasaki-Senshū Shipyard | 1942-10-12 | 1943-06-19 | 1943-11-20 | Sunk by and east of Saipan 1944-06-17. | ||
| 406 | Kawasaki-Senshū Shipyard | 1942-10-12 | 1943-06-19 | 1943-11-30 | Sunk by, and west of Mindoro 1945-02-01. Holmes contradicts the identification, indicating that Ro-115 acknowledged orders to proceed to Manila two days after the supposed date of its sinking, and was more likely to have been sunk by on 1945-02-10. | ||
| 407 | Kawasaki-Senshū Shipyard | 1943-01-16 | 1943-09-13 | 1944-01-21 | Sunk by north of the Admiralty Islands 1944-05-24. | ||
| 408 | Kawasaki-Senshū Shipyard | 1943-01-16 | 1943-09-13 | 1944-01-31 | Sunk by USN patrol bomber southeast of Saipan 1944-05-24. |