Japanese submarine I-29

I-29, code-named Matsu (松, Japanese for "pine tree"), was a B1 type submarine of the Imperial Japanese Navy used during World War II on two secret missions with Germany. She was sunk while returning from the second mission.

Construction
This was the most numerous class of Japanese submarines – almost 20 were built, of which only one (JAPANESE SUBMARINE I-36) survived. These boats were fast, had a long range, and carried a seaplane, launched via a forward catapult.

The keel of I-29 was laid on 20 September 1939 at the Yokosuka Naval Arsenal and launched on 29 September 1940. She was commissioned on 27 February 1942, into the 14th submarine squadron under the command of Lieutenant Commander (later Captain) Izu Juichi (伊豆壽市).

Yanagi missions
The Yanagi missions fell under the Tripartite Pact which provided for an exchange of personnel, strategic materials and manufactured goods between Germany, Italy and Japan. Initially, cargo ships were used to make the exchanges, but when that was no longer possible submarines were used.

Few submarines attempted this trans-oceanic voyage during World War II: JAPANESE SUBMARINE I-30 (April 1942), JAPANESE SUBMARINE I-8 (June 1943), JAPANESE SUBMARINE I-34 (October 1943) and the German submarines GS U-511 (August 1943) and GS U-234 (May 1945). Of these, I-30 was sunk by a mine and I-34 by the British submarine HMS Taurus (P399). Later, the famous Japanese submarine JAPANESE SUBMARINE I-52 would also share their fate. In 1945 the German U-234 had completed part of the voyage to Japan when news of Germany's surrender to the Allies was announced, and the submarine was intercepted and boarded off Newfoundland; this marked the end of the German-Japanese submarine exchanges.

Missions
I-29 participated in missions supporting the Operation Mo attack on Port Moresby in New Guinea, and also in the futile search for Task Force 16 which had launched the Doolittle Raid on Tokyo in April 1942.

I-29's reconnaissance of Sydney harbour on 23 May 1942 resulted in the attack on Sydney Harbour by Japanese midget submarine

First exchange


In April 1943, I-29 was tasked with a Yanagi mission. She was commanded by Captain Masao Teraoka, submarine flotilla commander – indicating the importance of the trip. She left Penang with a cargo that included two tons of gold as payment from Japan for weapons technology. She met Fregattenkapitän Werner Musenberg's Type IXD-1 U-boat, GS U-180 on 26 April 1943 off the coast of Mozambique.

During this meeting that lasted over 12 hours due to bad weather, the two submarines swapped several important passengers. U-180 transferred Netaji Subhas Chandra Bose, a leader of the Indian Independence Movement who was going from Berlin to Tokyo, and his adjutant, Abid Hasan. I-29 in turn transferred two Japanese Navy personnel who were to study U-boat building techniques in Germany: Commander (later posthumously promoted to rear admiral) Emi Tetsushiro, and Lieutenant Commander (later posthumously promoted to captain) Tomonaga Hideo (who was later connected with the German submarine GS U-234). Both submarines returned safely to their bases. I-29 landed her important passengers at Sabang on Weh Island, located to the north of Sumatra on 6 May 1943, instead of Penang, to avoid detection by British spies. Bose and Hasan's transfer is the only known record of a civilian transfer between two submarines of two different navies in World War II.

Second exchange
On December 17, 1943, I-29 was dispatched on a second Yanagi mission, this time to Lorient, France, under star Japanese submarine Commander Takakazu Kinashi Japan's highest-scoring submarine "ace". At Singapore she was loaded with 80 tons of raw rubber, 80 tons of tungsten, 50 tons of tin, two tons of zinc, and three tons of quinine, opium and coffee.

In spite of Allied Ultra decrypts of her mission, I-29 managed to reach Lorient on 11 March 1944. On her way she was refueled twice by German vessels. Also, she had three close brushes with Allied aircraft tracking her signals. One of which was an attack by six RAF aircraft including two Mosquito F Mk. XVIII fighters equipped with 57 mm cannon from No. 248 Squadron RAF off Cape Peñas, Bay of Biscay, at 43.66°N, -5.85°W, and the protection provided to her during the entry into Lorient by the Luftwaffe's only long range maritime fighter unit, V Gruppe/Kampfgeschwader 40 using Junkers Ju 88s. At least one Ju 88 was shot down by British fighters over Spanish waters. The Kriegsmarine also provided an escort of two destroyers and two torpedo boats.

She left Lorient 16 April 1944 for the long voyage home with a cargo of 18 passengers, torpedo boat engines, Enigma coding machines, radar components, a Walter HWK 509A rocket engine, and Messerschmitt Me 163 and Messerschmitt Me 262 blueprints for the development of the rocket plane Mitsubishi J8M. After an uneventful trip she arrived at Singapore on 14 July 1944, disembarking her passengers, though not the cargo.

Sinking
On her way back to Kure, Japan, she was attacked at Balintang Channel, Luzon Strait, near the Philippines by Commander W. D. Wilkins' "Wildcats" submarine task force: USS Tilefish (SS-307), USS Rock (SS-274) and USS Sawfish (SS-276), using Ultra signal intelligence. During the evening of 26 July 1944, she was spotted by Sawfish which fired four torpedoes at her. Three hit I-29, which sank immediately at 20.1°N, 121.55°W. Only one of her crewmen survived. Kinashi was honored by a rare two-rank posthumous promotion to rear admiral.

Media

 * I-29 is the submarine shown in the 2004 Bollywood film Netaji Subhas Chandra Bose: The Forgotten Hero where Netaji Subhas Chandra Bose travels with the German submarine U-180 around the Cape of Good Hope to the southeast of Madagascar, where he is transferred to the I-29, greeted aboard by her captain Masao Teraoka and continues the rest of the journey to Imperial Japan.