Japanese submarine I-51
Following World War I, the Imperial Japanese Navy General Staff began to re-consider submarine warfare as an element of fleet strategy. Before the war, the Japanese Navy regarded submarines as useful only for short-range coastal point defense. However, based on the success of the Imperial German Navy in deployment of long-range cruiser-submarines for commerce raiding Japanese strategists came to realize possibilities for using the weapon for long range reconnaissance, and in a war of attrition against an enemy fleet approaching Japan. Procurement for a large, long-range Japanese submarine was authorized in fiscal 1918 under the Eight-six fleet program, under the designation S22.
"Project S22" was based on the latest Royal Navy design, the British K class submarine. Japanese ties to Great Britain via the Anglo-Japanese Alliance were still strong. "Project S22" was laid down at Kure Naval Arsenal on 6 April 1921, launched on 29 November 1921 and completed on 20 June 1924.
Japanese submarine I-29
Only five other submarines had 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 "I-34" by the British submarine . Later, the famous Japanese submarine 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; this marked the end of the German-Japanese submarine exchanges.