Service history
Upon commissioning, I-366 was attached to the Yokosuka Naval District and was assigned to Submarine Squadron 11 for workups in the Kobe area. [2] She later moved to Kure where one of her diesel engines broke down in early September 1944. [2] Repairs took until early October 1944. [2] With her workups complete, she was reassigned to Submarine Squadron 7 on 2 October 1944, [2] and she arrived at Yokosuka in early November 1944. [2]
Transport missions
At 16:00 on 3 December 1944, I-366 departed Yokosuka bound for Pagan in the Mariana Islands on her first transport mission, carrying 51 metric tons of food and ammunition. [2] Shortly after her departure, she encountered a storm, and lost several supply containers filled with rice on her afterdeck that were washed overboard. [2] On 10 December 1944, she was on the surface recharging her batteries when she detected an aircraft and crash-dived, intending to dive to 130 feet (40 m), but a valve malfunctioned, causing her to descend to 290 feet (88 m) and develop a leak through her periscope shaft. [2] She arrived at Pagan on the evening of 14 December 1944, transferred her cargo to Daihatsu-class landing craft, embarked 49 passengers, including some military pilots, and got back underway after only four hours. [2] At least 10 of her passengers were wounded personnel, and six of them died during the voyage to Japan. [2] She arrived at Yokosuka at 10:00 on 28 December 1944 and disembarked her 43 surviving passengers. [2]
After arriving at Yokosuka, I-366 began a refit, during which a Type 13 air-search radar was installed. [2] As of 1 January 1945, she was part of Submarine Squadron 7 along with the submarines I-361, I-362, I-363, I-367, I-368, I-369, I-370, and I-371. [2]
With her overhaul complete, I-366 departed Yokosuka on 29 January 1945 for her second transport voyage, bound for Truk with a cargo of aviation gasoline and spare parts for the Nakajima C6N1 Saiun ("Iridiscent Cloud"; Allied reporting name "Myrt") reconnaissance aircraft of the 141st Naval Air Group, which needed the fuel and parts for reconnaissance flights over the United States Navy anchorage at Ulithi Atoll. [2] Soon after departure, her crew discovered that her shortwave radio mast would not retract, so she returned to Yokosuka. [2] With the mast repaired, she again put to sea that evening, spent the night of 29–30 January 1945 in the Tateyama Bight, and then set out into the Pacific Ocean. [2] During her voyage, one of her lookouts reported sighting an Allied cruiser on southwesterly headed at 04:48 on 10 February 1945. [2]
On 12 February 1945, I-366 arrived at Truk, where she unloaded 33 tons of fuel and some other cargo. [2] She then headed for Mereyon Island at Woleai in the Caroline Islands, which she reached on 16 February 1945. [2] She unloaded 51 tons of food and ammunition into nine Daihatsus, embarked 42 or 43 passengers (sources disagree), and got back underway, bound for Yokosuka. [2] During her voyage, she sighted an Iwo Jima-bound Allied convoy in late February 1945. [2] She arrived at Yokosuka on 3 March 1945. [2]
Kaiten carrier
Submarine Squadron 7 was deactivated on 20 March 1945 and I-366 was reassigned to Submarine Division 15. [2] Meanwhile, after reaching Yokosuka, I-366 was converted from a transport submarine into a kaiten suicide attack torpedo carrier, the conversion involving the removal of her 140-millimeter (5.5 in) deck gun and Daihatsu-class landing craft and their replacement with fittings allowing her to carry five kaitens on her deck. [2] Unlike some of the other Type D1 submarines, she was not equipped with conventional torpedo tubes. [2]
While I-366 was undergoing conversion, U.S. forces captured advanced bases and anchorages in the Kerama Islands southwest of Okinawa between 26 and 29 March 1945, [2] and the Battle of Okinawa began when U.S. forces landed on Okinawa itself on 1 April 1945. [2] With her conversion complete, I-366 and the submarine I-367 were designated the Shimbu ("God's Warriors") Kaiten Group, [3] and on 2 May 1945 I-366 received orders to get underway on 4 May 1945 for the kaiten base at Hikari, where she was to load kaitens, and then deploy to the waters between Okinawa and Ulithi Atoll to attack Allied ships. [2] While conducting kaiten launch exercises off Hikari on 6 May 1945, however, she detonated a magnetic mine at around 12:00, and the explosion damaged her propellers and stern planes. [2] A tug from Hikari arrived and took her under tow. [2] The damage prevented her from taking part in the Shimbu mission. [2]
I-366 underwent repairs at the Kure Naval Arsenal in Kure. [2] While she was under repair, a new radar was installed aboard her. [2] By 20 July 1945, her repairs were complete and she was engaged in kaiten training. [2]
By 1 August 1945, I-366 was part of the TamonKaiten Group along with the submarines I-47, I-53, I-58, I-363, and I-367. [2] With five kaitens on board, she got underway from Hirao that day bound for a patrol area southeast of Okinawa. [2]
On 11 August 1945, I-366 sighted an Allied convoy 500 nautical miles (930 km; 580 mi) north of Palau and attempted to launch all five of her kaitens. [2] Two were defective, but she launched the other three at very long range. [2] I-366 did not detect any hits, and her navigator opined that all three kaitens had run out of fuel before reaching the convoy and their pilots had suffocated. [2] I-366 nonetheless claimed three Allied transports sunk in the attack, although postwar analysis assessed no damage to the convoy's ships. [2]
I-366 set course for Japan. While she was en route, she received word on 15 August 1945 that Emperor Hirohito had announced the end of hostilities between Japan and the Allies that day. [2] She arrived at Kure on 18 August 1945 [2] and surrendered to the Allies in September 1945. [2]
I-58 was a Japanese B3 type cruiser submarine that served in the final year of World War II. Her only significant wartime success came with a conventional torpedo attack upon USS Indianapolis on 30 July 1945. She was modified to carry Kaiten manned torpedoes, making several attacks that inflicted minor damage in exchange for every Kaiten launched being sunk. The submarine surrendered in September 1945, and was later scuttled by the United States Navy.
I-370 was an Imperial Japanese Navy Type D1 transport submarine. Completed and commissioned in September 1944, she served in World War II and was converted into a kaiten suicide attack torpedo carrier in January 1945. She was sunk in February 1945 while operating during the Battle of Iwo Jima.
I-159, originally I-59, was an Imperial Japanese Navy Kaidai-class cruiser submarine of the KD3B sub-class in commission from 1930 to 1945. During World War II, she made two war patrols in the Indian Ocean, took part in the Battle of Midway, and served as a training submarine before ending the war as a kaiten suicide attack torpedo carrier. She surrendered at the end of the war and was scuttled in 1946.
I-55, later renumbered I-155, was an Imperial Japanese Navy Kaidai-class cruiser submarine of the KD3A sub-class commissioned in 1927. Early in World War II, she supported Japanese forces in the invasion of Malaya and the Dutch East Indies campaign before assuming training duties in Japan, interrupted briefly in 1943 by her participation in the Aleutian Islands campaign. She became a kaiten manned suicide attack torpedo carrier in 1945 before surrendering at the end of the war. She was scuttled in 1946.
I-57, later I-157, was an Imperial Japanese Navy Kaidai-class cruiser submarine commissioned in 1929. During World War II, she supported Japanese forces during the invasion of Malaya in December 1941, the Dutch East Indies campaign in early 1942, and the Battle of Midway in June 1942. She then served on training duties — except for a brief period of participation in the Aleutian Islands campaign in 1943 — until she was converted into a kaiten manned suicide attack torpedo carrier in 1945. She surrendered to the Allies at the end of the war in 1945 and was scuttled in 1946.
I-16 was one of five Type C cruiser submarines of the C1 sub-class built for the Imperial Japanese Navy, Commissioned in 1940, she deployed a midget submarine for the attack on Pearl Harbor and for an attack on ships at Diego-Suarez in Madagascar, conducted an anti-shipping patrol in the Indian Ocean, and took part in the Guadalcanal campaign, New Guinea campaign, and Bougainville campaign before she was sunk in May 1944.
I-47 was the second of three Type C cruiser submarines of the C2 sub-class built for the Imperial Japanese Navy. Commissioned in July 1944, she operated as a kaiten manned suicide attack torpedo carrier during the final year of World War II. Surrendered at the end of the war, she was scuttled by the United States Navy in 1946.
The second I-53 was the second of three Type C cruiser submarines of the C3 sub-class built for the Imperial Japanese Navy. Commissioned in February 1944, she operated primarily as a kaiten manned suicide attack torpedo carrier during the final year of World War II and sank the destroyer escort USS Underhill (DE-682). Surrendered at the end of the war, she was scuttled by the United States Navy in 1946.
I-36 was an Imperial Japanese Navy B1 type submarine. Completed and commissioned in 1942, she served in World War II, operating in the Guadalcanal campaign, New Guinea campaign, Aleutian Islands campaign, and the Marshall Islands. She finished the war as a kaiten manned suicide attack torpedo carrier, operating against Allied ships at Ulithi Atoll and in the Philippine Sea. The only submarine of her class to survive the war, she surrendered to the Allies in September 1945 after the end of the war and was scuttled by the United States Navy in 1946.
I-43 was an Imperial Japanese Navy Type B2 submarine. Completed and commissioned in 1943, she served in World War II and was sunk during her first deployment in February 1944.
The second I-56 was an Imperial Japanese Navy Type B3 submarine. Completed and commissioned in June 1944, she served in the late stages of World War II and took part in the Philippines campaign at the time of the Battle of Leyte Gulf. She then operated as a kaiten suicide attack torpedo carrier, including during the Battle of Okinawa, before she was lost in April 1945.
I-44 was an Imperial Japanese Navy Type B2 submarine. Completed and commissioned in January 1944, she served in the late stages of World War II, she conducted war patrols in the Pacific Ocean as a conventional submarine before she was converted into a kaiten suicide attack torpedo carrier. She then conducted kaiten operations during the Battle of Iwo Jima and the Battle of Okinawa before she was sunk in April 1945.
I-368 was an Imperial Japanese Navy Type D1 transport submarine. Completed and commissioned in August 1944, she served in World War II and was converted into a kaiten suicide attack torpedo carrier in January 1945. She was sunk in February 1945 while operating during the Battle of Iwo Jima.
I-361 was an Imperial Japanese Navy Type D1 transport submarine. Completed and commissioned in May 1944, she served in World War II and conducted transport missions between Japan and Wake Island until she was converted into a kaiten suicide attack torpedo carrier 1945. She was sunk during her first kaiten mission in May 1945.
I-363 was an Imperial Japanese Navy Type D1 transport submarine. Completed and commissioned in July 1944, she served in World War II and conducted transport missions between Japan and outlying islands until she was converted into a kaiten suicide attack torpedo carrier. She survived the war, but sank after striking a mine in the weeks immediately following its conclusion.
I-367 was an Imperial Japanese Navy Type D1 transport submarine. Completed and commissioned in August 1944, she served in World War II and conducted transport missions between Japan and outlying islands until she was converted into a kaiten suicide attack torpedo carrier. She survived the war, surrendered to Allied forces in 1945, and was scuttled in 1946.
I-372 was an Imperial Japanese Navy Type D1 transport submarine. Completed and commissioned in November 1944, she served in World War II and was sunk in July 1945.
Ro-41 was an Imperial Japanese Navy Kaichū type submarine of the K6 sub-class. Completed and commissioned in November 1943, she served in World War II and conducted six war patrols, sinking a destroyer escort USS Shelton (DE-407) on one of them, before she was sunk in March 1945.
Ro-46 was an Imperial Japanese Navy Kaichū type submarine of the K6 sub-class. Completed and commissioned in February 1944, she served in World War II, including operations related to the Marianas campaign, the Philippines campaign, and the Battle of Okinawa. She disappeared in April 1945 during her fifth war patrol.
Ro-109 was an Imperial Japanese Navy Ro-100-class submarine. Completed and commissioned in April 1943, she served in World War II, operating off the Solomon Islands, New Guinea, the Admiralty Islands, Truk, the Philippine Islands, and Okinawa. She was sunk in April 1945 during her tenth war patrol.
Japan
