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 () 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: (April 1942), (June 1943), (October 1943) and the German submarines (August 1943) and (May 1945). Of these, I-30 was sunk by a mine and