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.
Yokosuka Naval Arsenal
The Yokosuka Naval District was established at Yokosuka, Kanagawa in 1884, as the first of the naval districts responsible for the defense of the Japanese home islands, and the Yokosuka Shipyards was renamed the Yokosuka Naval Arsenal in 1903. Japan had purchased five submarines from the American Electric Boat Company during the Russo-Japanese War of 1904–1905. These Holland Type VII submarines were built by Arthur Leopold Busch as he traveled to Japan during this time. Mr. Busch was a naval architect and shipbuilder who represented the newly organized company (Electric Boat Company) now located at the Quincy Massachusett's shipyard known as the Fore River Ship and Engine Company. These first five submarines became Japan's (IJN) initial entry into the theater of underwater warfare that began nearly the same time as the outbreak of the war. Another representative of Electric Boat, Frank Cable, an electrician working for Isaac L. Rice's company trained two Japanese crews in the operation of such craft.