# Ha-201-class submarine

The Ha-201-class submarine (波二百一型潜水艦, Ha-ni-hyaku-ichi-gata sensuikan) were a class of small submarines designed for the Imperial Japanese Navy (IJN). They were first deployed in 1945, but never saw combat. The Ha-201's were designed from the outset to have high underwater speed and were based on the earlier Submarine No.71 prototype. The official designation of the submarine was Sentaka-Shō type submarine (潜高小型潜水艦, Sen-Taka-Ko-gata sensuikan, "Submarine High speed-Small type"). The type name was shortened to Suichū Kōsoku Sensuikan Ko-gata (水中高速潜水艦小型, Underwater High speed Submarine Small type).

## Design and description

At the end of 1944, the Imperial Japanese Navy decided it needed large numbers of high-speed coastal submarines to defend the Japanese Home Islands against an anticipated Allied invasion (named Operation Downfall by the Allies). To meet this requirement, the Ha-201-class submarines were designed as small, fast submarines incorporating many of the same advanced ideas implemented in the German Type XXI and Type XXIII submarines. They were capable of submerged speeds of almost 14 knots (26 km/h; 16 mph).
The Ha-201 class displaced 325 metric tons (320 long tons) surfaced and 447 metric tons (440 long tons) submerged. The submarines were 53 meters (173 ft 11 in) long, had a beam of 4.00 meters (13 ft 1 in) and a draft of 3.44 meters (11 ft 3 in). For surface running, the submarines were powered by a single 400-brake-horsepower (298 kW) diesel engine that drove one propeller shaft. When submerged the propeller was driven by a 1,250-shaft-horsepower (932 kW) electric motor. They could reach 11.8 knots (21.9 km/h; 13.6 mph) on the surface and 13.9 knots (25.7 km/h; 16.0 mph) submerged. On the surface, the Ha-201-class submarines had a range of 3,000 nautical miles (5,600 km; 3,500 mi) at 10 knots (19 km/h; 12 mph); submerged, they had a range of 105 nmi (194 km; 121 mi) at 2 knots (3.7 km/h; 2.3 mph). Their armament consisted of two 533-millimeter (21 in) torpedo tubes with four torpedoes and a single mount for a 7.7-millimeter machine gun.

## Construction

The Japanese planned to build 79 Ha-201-class submarines (Submarines No. 4911 through 4989) under the Maru Sen Programme, prefabricating large sections of the boats, then completing them on the slipway. This was an ambitious goal considering the U.S. bombing campaign, which disrupted Japanese production, and by the time hostilities ceased on 15 August 1945 the Japanese had laid down only 22 submarines and completed only ten.

## Service

None of the submarines made operational patrols. Except for one submarine that was wrecked, the Allies after the war scuttled all the submarines that had been completed as well as all the incomplete ones that had been launched. Those which remained on the building ways at the end of the war were scrapped incomplete.

## Boats

| Boat # | Name | Builder | Laid down | Launched | Completed | Fate |
| 4911 | Ha-201 | Sasebo Naval Arsenal | 01-03-1945 | 23-04-1945 | 31-05-1945 | Decommissioned 30-11-1945. Scuttled off Gotō Islands 01-04-1946. |
| 4912 | Ha-202 | Sasebo Naval Arsenal | 01-03-1945 | 23-04-1945 | 31-05-1945 | Decommissioned 30-11-1945. Scuttled off Gotō Islands 01-04-1946. |
| 4913 | Ha-203 | Sasebo Naval Arsenal | 05-04-1945 | 25-05-1945 | 26-06-1945 | Decommissioned 30-11-1945. Scuttled off Gotō Islands 01-04-1946. |
| 4914 | Ha-204 | Sasebo Naval Arsenal | 05-04-1945 | 01-06-1945 | 25-06-1945 | Decommissioned 30-11-1945. Grounded at Aburatsu Bay, October 1946. Salvaged and scrapped August 1948. |
| 4915 | Ha-205 | Sasebo Naval Arsenal | 17-04-1945 | 14-05-1945 | 03-07-1945 | Decommissioned 30-11-1945. Scuttled at Iyo Nada, May 1946. |
| 4916 | Ha-206 | Kawasaki-Senshū Shipyard | 19-03-1945 | 10-07-1945 | | Incomplete at end of war (95%), sunk by typhoon 25-08-1945. Salvaged and scuttled at Kii Channel 06-05-1946. |
| 4917 | Ha-207 | Sasebo Naval Arsenal | 23-04-1945 | 26-05-1945 | 14-08-1945 | Decommissioned 30-11-1945. Scuttled off Sasebo 05-04-1946. |
| 4918 | Ha-208 | Sasebo Naval Arsenal | 01-05-1945 | 26-05-1945 | 04-08-1945 | Decommissioned 30-11-1945. Scuttled off Gotō Islands 01-04-1946. |
| 4919 | Ha-209 | Sasebo Naval Arsenal | 07-05-1945 | 31-05-1945 | 04-08-1945 | Decommissioned 30-11-1945. Scrapped August 1946. |
| 4920 | Ha-210 | Sasebo Naval Arsenal | 14-05-1945 | 10-06-1945 | 11-08-1945 | Decommissioned 30-11-1945. Scuttled off Sasebo 05-04-1946. |
| 4921 | Ha-211 | Kawasaki-Senshū Shipyard | 01-04-1945 | April 1946 | | Incomplete at end of war (40%). Scuttled at Kii Channel 06-05-1946. |
| 4922 | Ha-212 | Kawasaki-Kōbe Shipyard | 10-04-1945 | 25-06-1945 | | Incomplete at end of war (95%). Scuttled at Kii Channel, May 1946. |
| 4923 | Ha-213 | Mitsubishi-Kōbe Shipyard | 15-05-1945 | 29-07-1945 | | Incomplete at end of war (93%). Scuttled at Kii Channel 06-05-1946. |
| 4924 | Ha-214 | Mitsubishi-Kōbe Shipyard | 15-05-1945 | 15-08-1945 | | Incomplete at end of war (75%). Scuttled at Kii Channel 06-05-1946. |
| 4925 | Ha-215 | Sasebo Naval Arsenal | 22-05-1945 | 15-05-1945 | | Incomplete at end of war (95%). Scuttled off Sasebo 05-04-1946. |
| 4926 | Ha-216 | Sasebo Naval Arsenal | 27-05-1945 | 19-06-1945 | 16-08-1945 | Decommissioned 30-11-1945. Scuttled off Sasebo 05-04-1946. |
| 4927 | Ha-217 | Sasebo Naval Arsenal | 02-06-1945 | 26-06-1945 | | Incomplete at end of war (90%). Scuttled off Sasebo 05-04-1946. |
| 4928 | Ha-218 | Sasebo Naval Arsenal | 08-06-1945 | 02-07-1945 | | Incomplete at end of war (90%). Scrapped, December 1946. |
| 4929 | Ha-219 | Sasebo Naval Arsenal | 15-06-1945 | 12-07-1945 | | Incomplete at end of war (90%). Scuttled off Sasebo 05-04-1946. |
| 4930 | Ha-220 | Kawasaki-Senshū Shipyard | 10-05-1945 | | | Incomplete at end of war (20%). Scrapped, June 1946. |
| 4931 | Ha-221 | Mitsubishi-Kōbe Shipyard | 20-04-1945 | 04-08-1945 | | Incomplete at end of war (85%). Scuttled at Kii Channel, 06-05-1946. |
| 4932 | Ha-222 | Kawasaki-Senshū Shipyard | 15-05-1945 | | | Incomplete at end of war (15%). Scrapped, June 1946. |
| 4933 | Ha-223 | Kawasaki-Kōbe Shipyard | 01-05-1945 | | | Incomplete at end of war (60%). Scrapped, June 1946. |
| 4934 | Ha-224 | Mitsubishi-Kōbe Shipyard | 07-06-1945 | | | Incomplete at end of war (55%). Scrapped, June 1946. |
| 4935 | Ha-225 | Mitsubishi-Kōbe Shipyard | 07-06-1945 | | | Incomplete at end of war (45%). Scrapped, June 1946. |
| 4936 | Ha-226 | Mitsubishi-Kōbe Shipyard | 16-06-1945 | | | Incomplete at end of war (35%). Scrapped, June 1946. |
| 4937 | Ha-227 | Mitsubishi-Kōbe Shipyard | 10-07-1945 | | | Incomplete at end of war (25%). Scrapped, June 1946. |
| 4938 | Ha-228 | Sasebo Naval Arsenal | 21-06-1945 | 18-07-1945 | | Incomplete at end of war (75%). Scuttled off Sasebo 05-04-1946. |
| 4939 | Ha-229 | Sasebo Naval Arsenal | 27-06-1945 | 27-07-1945 | | Incomplete at end of war (75%). Scrapped, December 1946. |
| 4940 | Ha-230 | Sasebo Naval Arsenal | 03-07-1945 | | | Incomplete at end of war (60%). Scrapped, December 1946. |
| 4941 | Ha-231 | Sasebo Naval Arsenal | 12-07-1945 | | | Incomplete at end of war (50%). Later scrapped. |
| 4942 | Ha-232 | Sasebo Naval Arsenal | 18-07-1945 | | | Incomplete at end of war (40%). Later scrapped. |
| 4943 | Ha-233 | Kawasaki-Senshū Shipyard | 01-06-1945 | | | Incomplete at end of war (10%). Later scrapped. |
| 4944 | Ha-234 | Kawasaki-Kōbe Shipyard | 15-05-1945 | | | Incomplete at end of war (50%). Scrapped, June 1946. |
| 4945 | Ha-235 | Kawasaki-Senshū Shipyard | 01-06-1945 | | | Incomplete at end of war (10%). Later scrapped. |
| 4946 | Ha-236 | Kawasaki-Kōbe Shipyard | 01-06-1945 | | | Incomplete at end of war (40%). Scrapped, June 1946. |
| 4947 | Ha-237 | Mitsubishi-Kōbe Shipyard | 10-07-1945 | | | Incomplete at end of war (25%). Scrapped, June 1946. |
| 4948 | Ha-238 | Mitsubishi-Kōbe Shipyard | 01-08-1945 | | | Incomplete at end of war (15%). Scrapped, June 1946. |
| 4949 | Ha-239 | Mitsubishi-Kōbe Shipyard | 01-08-1945 | | | Incomplete at end of war. Scrapped, June 1946. |
| 4950 | Ha-240 | Mitsubishi-Kōbe Shipyard | 01-08-1945 | | | Incomplete at end of war. Scrapped, June 1946. |
| 4951 - 4955 | | | | | | Construction not started by end of war. |
| 4956 | Ha-246 | Kawasaki-Senshū Shipyard | 13-07-1945 | | | Incomplete ay end of war (5%). Later scrapped. |
| 4957 | Ha-247 | Kawasaki-Kōbe Shipyard | 26-06-1945 | | | Incomplete at end of war. Later scrapped. |
| 4958 - 4989 | | | | | | Construction not started by end of war. |

## Footnotes

* ↑ The 潜高小 read as "Sentaka-Shō", but the 潜高小型 read as "Sentaka-Ko-gata", 高速 read as "Kō-soku" and 小型 read as "Ko-gata" in Japanese.
* 1 2 3 4 5 6 7 8 9 10 11 12 13 Hackett, Bob; Sander Kingsepp (2015). "Sen Taka Sho Type". Sensuikan!. Combinedfleet.com. Retrieved 9 October 2020.
* ↑ 波号第201潜水艦 (Ha-Gō Dai-201 Sensuikan). The same shall apply hereinafter.