Imperial Japanese Navy Submarine I-29 and the Secret missions to Germany during WWII
The so-called Yanagi missions consisted on intercontinental travels and trips done by Axis Powers ships to exchange strategic resources and information between Italy, Germany and Japan. Due to the war ships could not further continue the exchange program and this task was assigned to submarines.
From the Imperial Japanese Navy, only five other submarines had attempted the intercontinental travel:
- I-30 (April 1942),
- I-8 (June 1943),
- I-34 (October 1943)
- and the German submarines U-511 (August 1943) and U-234 (May 1945).
Of these, I-30 was sunk by a mine and I-34 by the British submarine HMS Taurus. Later, the famous 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 subsequently was intercepted and boarded off Newfoundland.
In April 1943, I-29 was tasked with a Yanagi mission. She was commanded by Captain Masao Teraoka and met Fregattenkapitän Werner Musenberg’s Type IXD-1 U-boat, U-180 on 26 April 1943 off the coast of Mozambique. The I-29 was also known as code-named Matsu “pine tree”.
First trip: These two Axis submarines swapped several important passengers including a leader of the Indian Independence Movement who was going from Berlin to Tokyo, Also there were exchange of two tonnes of gold ingots as payment from Japan for weapons technology.
Second trip: On December 17, 1943, I-29 was planned on a second Yanagi mission, this time to Lorient, France under Commander Takakazu Kinashi. 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.
The I-29 managed to reach Lorient 11 March 1944 even though the allies had the advantage of the broken code done by ULTRA. On her way she was refueled twice by German vessels. 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
- Messerschmitt Me 163 & Me-262 blueprints to build the rocket plane Mitsubishi J8M.
After a calm trip she arrived at Singapore on 14 July 1944, disembarking her passengers. The cargo remained aboard the ship.
Just after leaving Singapore, she was attacked the “Wildcats” submarine taskforce consisting of Tilefish, Rock and Sawfish, using Ultra signal intelligence. Only one of her crewmen survived.
The I-29’s Commanding Officer, Commander Takakazu Kinashi was also among the dead. Japan’s highest-scoring submarine “ace”. Kinashi was honored by a rare two-rank posthumous promotion to Rear Admiral.