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.
Construction and commissioning
I-36 was laid down on 4 December 1940 at the Yokosuka Navy Yard at Yokosuka, Japan, with the name Submarine No. 149. She was both renamed I-36 and launched on 1 November 1941. She finished her acceptance trials on 20 September 1942, and was completed and commissioned on 30 September 1942.
Service history Upon commissioning, I-36 was attached to the Kure Naval District and assigned to the Kure Submarine Squadron. She moved to Agenosho Bay for work-up in the Iyo-nada in the Seto Inland Sea. With her work-up completed, she arrived at Kure on 30 November 1942.
On 15 December 1942, I-36 was reassigned to Submarine Division 15 in Submarine Squadron 1 in the 6th Fleet. She departed Kure at 13:00 on 18 December 1942 and proceeded to Truk, which she reached on 28 December 1942.
Guadalcanal campaign Assigned to take part in submarine cargo runs to supply Japanese forces on Guadalcanal fighting in the Guadalcanal campaign, I-36 got back underway from Truk on the same day she arrived. She proceeded to the Japanese anchorage in the Shortland Islands off Shortland Island, arriving there on 31 December 1942. After the submarine arrived at Shortland after a supply run to Kamimbo Bay on the northwestern coast of Guadalcanal, I-36′s commanding officer and navigation officer went aboard I-31 on 1 January 1943 to receive a briefing on the naval situation in the Kamimbo Bay area and the cargo unloading procedures there. During the afternoon, I-36 loaded a cargo of 20 tons of rice in supply drums, then conducted a test dive off Shortland Island. She got underway for Guadalcanal at 18:00. A half an hour after dark on 3 January 1943, she surfaced at Kamimbo Bay, discharged her cargo into four Daihatsu-class landing craft, and headed back for Shortland Island, where she arrived at 07:39 on 5 January 1943.
On 6 January 1943, I-36 departed Shortland for her second supply run at 18:00. Arriving at Kamimbo Bay after dark on 8 January, she unloaded her cargo — 12 rubber containers of food — into Daihatsus, embarked 39 Imperial Japanese Army soldiers, and got back underway, returning to the Shortland anchorage at 06:30 on 10 January 1943. She left the same day at 18:00 bound for Rabaul on New Britain.
New Guinea campaign, January–February 1943
I-36 arrived at Rabaul on 11 January 1943 at 11:21, and that day the commander of Submarine Squadron 1 briefed her commanding officer on her next assignment, the delivery of supplies at Buna on the coast of New Guinea in support of Japanese forces fighting in the New Guinea campaign. She departed Rabaul at 12:00 on 14 January 1943 on her first supply run, arrived at the Mambare River estuary at Buna on 17 January, unloaded cargo and embarked 47 soldiers, and put back to sea, returning to Rabaul at 09:36 on 18 January 1943. She left Rabaul on her second run at 18:06 on 22 January 1943, arriving at the Mambare River on 24 January to unload 13 supply drums and bring aboard 39 soldiers, and returning to Rabaul on 27 January 1943. On her next run to New Guinea, she visited the Mambare on 30 January 1943, delivering 23 tons of supplies and evacuating 59 soldiers.
I-36 remained active on the Buna run into February 1943, departing Rabaul at 11:00 on 3 February, visiting the Mambare estuary on 5 February to discharge 18 tons of supplies and embark 40 soldiers, and returning to Rabaul at 08:14 on 7 February. She then began runs to Lae, also on New Guinea's coast, departing Rabaul on 14 February 1943 and delivering 45 tons of supplies at Lae after dark on 16 February, and getting back underway after embarking 90 soldiers. Early in her return voyage to Rabaul, she sighted two Allied motor torpedo boats off Lae at 01:10 on 17 February 1943 and submerged. They subjected her to a brief depth-charge attack, but she escaped unscathed and arrived at Rabaul at 10:00 on 18 February 1943. She then made her final run to Lae, leaving Rabaul at 10:00 on 20 February 1943, visiting Lae after dark on 22 February to drop off 40 tons of supplies and bring 72 soldiers aboard, and returning to Rabaul at 08:50 on 24 February 1943.
Several staff officers of Submarine Squadron 1 boarded I-36 with their luggage and documents at Rabaul, and she got underway at 0900 on 25 February bound for Truk, which she visited from 27 February to 2 March 1943. Then she headed for Japan, where she arrived at Yokosuka at 07:00 on 7 March 1943. Her crew was granted four weeks of leave at the resort at Atami while I-36 underwent upkeep and repairs.
Typhoon At 15:30 on 6 April 1943, I-36 departed Yokosuka bound for Truk. Her voyage had barely begun, however, when a typhoon struck while she was in the Philippine Sea. The weather prevented her from completing the recharging of her batteries, forcing her to stay surfaced while waves pummeled her. She turned back to try to find shelter from the worst of the storm in the lee of Miyake-jima in the Izu Islands. Early on the morning of 7 April 1943, a huge wave swamped her, flooding her control room and main engine room. Inspecting the damage, her crew found one bent piston rod in each of her diesel engines. I-36 turned back for Yokosuka, dumping diesel fuel along the way to gain additional buoyancy.
On 8 April 1943, I-36 was east of Chōshi lighthouse on Honshu when she finally was able to determine her true position for the first time since departing Yokosuka. With her starboard diesel engine repaired, she made for Yokosuka at . She reached Yokosuka on 9 April 1943 at 09:30 and subsequently began repairs at Yokosuka Navy Yard.
Aleutian Islands campaign
On 13 May 1943, I-36 was assigned to the Northern Unit in the 5th Fleet for service in the Aleutian Islands campaign. Before departing Japan for the Aleutian Islands, she took part in towing tests for the Unkato cargo container — a submersible cargo container that could carry up to 377 tons of supplies, designed for a one-way trip in which the cargo's recipients released, recovered, and unloaded it — in the Seto Inland Sea on and again from 3 to 5 June 1943. She then departed Kure at 10:00 on 7 June 1943 bound for Paramushiro in the Kurile Islands, which she reached on 13 June 1943.
Upon I-36′s arrival, her commanding officer received a briefing on the situation in the Aleutians from the commander of Submarine Squadron 1. The Americans had annihilated the Japanese garrison on Attu during the Battle of Attu of 11–30 May 1943, isolating the last remaining Japanese garrison on Kiska. Even before the fall of Attu, Japanese Imperial General Headquarters had decided on 21 May 1943 to evacuate the Kiska garrison by submarine beginning on 26 May 1943. I-36 was assigned to the effort to keep the Kiska garrison supplied while continuing the ongoing evacuation.
Towing an Unkato supply container, I-36 got underway from Paramushiro at 10:00 on 15 June 1943 for her first supply run, with an estimated time of arrival at Kiska of 19 June. She soon lost the Unkato container in heavy seas, and while heading northeast at on 17 June 1943, she nearly ran aground on Middle Reef in the North Pacific Ocean south of Buldir Island. Concerned with an alarming rise in losses and near-losses of submarines in the Aleutians — including I-36′s near-grounding — the commander of Submarine Squadron 1 ordered the suspension of the Kiska supply effort on 21 June 1943, and I-36 turned back. She was in the Bering Sea north of Kiska an hour before dawn on 24 June 1943 when Submarine Squadron 1 ordered her to abandon her supply mission entirely and return to Paramushiro, which she reached on 25 June. I-36 and the submarine refueled from the oiler on 27 June 1943.
I-36 departed Paramushiro on 2 July 1943 for an operating area east and north of Kiska. The Japanese completed the evacuation of Kiska on 28 July, and after an uneventful patrol, I-36 received orders on 4 August 1943 to return to Paramushiro. On 6 August, she got underway from Paramushiro and set course for Yokosuka, which she reached on 10 August 1943 to undergo an overhaul and have a radar detector installed.
Hawaii reconnaissance operation
On 16 August 1943, Combined Fleet Headquarters ordered I-36 to conduct a reconnaissance seaplane flight over Pearl Harbor in Hawaii, with the flight to take place on or about 20 September 1943. She embarked a Yokosuka E14Y1 (Allied reporting name "Glen") floatplane and its two-man crew and began launch and recovery tests with the plane in the Seto Inland Sea. During a launch test on 5 September 1943, one of her diesel engines broke down, and she returned to Yokosuka for repairs.
I-36 departed Yokosuka on 8 September 1943 bound for Hawaii with an E14Y1 floatplane, its two-man crew, and the Combined Fleet's Staff Operations Officer for Submarines embarked, the latter personally supervising the operation. She was north of Niihau, Hawaii, on 18 September 1943 when her radar detector picked up nearby radar emissions, and soon thereafter her lookouts sighted a large American patrol plane approaching. She crash-dived and avoided detection. At dawn on 20 September 1943, she was off the western tip of Niihau and surfaced several times to launch her plane, but made numerous contacts and submerged again each time. Deciding that a radar station on nearby Kauai could be detecting I-36 when she surfaced, her commanding officer and the Combined Fleet staff officer decided to move to waters southwest of the island of Hawaii, believing I-36 was likely to be detected there, and to postpone the flight until the next favorable moon phase in mid-October 1943.
With I-36 southeast of Hawaii on 12 October, the two officers decided to launch the E14Y1 from a point south-southwest of Oahu after dark on 16 October 1943. Accordingly, I-36 launched the plane from that point on the evening of 16 October. The plane approached Oahu at minimum altitude to avoid detection by American radar, but was detected when it climbed over Pearl Harbor to make its observations. Several searchlights illuminated it, and it dived away to head for the recovery area at low altitude. As it crossed the coast of Oahu, its observer transmitted a single dash in Morse code, prompting I-36 to head for the recovery area at flank speed. I-36 received a garbled message from the plane indicating the sighting of four aircraft carriers, four battleships, five cruisers, and 17 destroyers in the harbor, but she never saw or heard from the plane and its two-man crew again despite searching the recovery area for five hours, flashing her running lights and an Aldis lamp, and making a number of efforts to establish radio contact with it. She transmitted a report of the reconnaissance flight's results and the loss of the floatplane and its crew to 6th Fleet headquarters on 18 October 1943.
I-36 was south-southwest of Hawaii on 19 October 1943 when she sighted a convoy of six U.S. Navy fleet oilers steaming southwest at and began an attack approach, but escorting destroyers forced her to go deep and lose contact. She reported the sighting on 20 October, prompting the 6th Fleet to order the submarines , , I-169, and to intercept the convoy. She also received orders on 20 October 1943 to shell the airfield on Canton Island, which she did on 1 November 1943, firing 13 rounds. She called at Kwajalein from 7 to 9 November 1943 to refuel, then arrived at Truk on 12 November 1943.
New Guinea campaign, December 1943–January 1944