旧日本海軍潛水艇「伊４００」

Recently the Yomiuri News on-line reported the following:

旧日本海軍の潜水艦「伊４００」ハワイ沖で発見

　米ハワイ大の海洋調査研究所は３日、旧日本海軍の大型潜水艦「伊４００」がハワイ沖の海底で見つかったと発表した。

　「伊４００」は全長約１２０メートルで、戦中、米本土への攻撃用に開発された。給油なしで地球を１周半できたとされ、原子力潜水艦が開発されるまでは世界最大級だった。

　米海軍は戦後、旧ソ連への技術の拡散防止などを理由に撃沈した。同研究所が今年８月、深さ約７００メートルの海底で発見したという。

（2013年12月5日00時20分  読売新聞）

(試譯文)

     The Oceanographic Investigation Research Institute of the U.S. University of Hawaii on the 3rd announced that a large-sized submarine of the Imperial Japanese Navy the "I- 400" was found on the seabed off Hawaii.

     "I-400" was about 120 meters in full length and was developed to attack the US homeland during the War. Until the nuclear submarine was developed, it was the world's largest class and supposedly it was able to go around the earth 1 and a half times without oil refueling.

     After the war the US Navy sank it for reasons of non-proliferation of the technology to the former Soviet Union etc. The research institute said that in August this year they discovered it on the seabed at a depth of about 700 meters.

(00:20 on December 5, 2013    Yomiuri Shimbun)

 According to the Wikipedia, I-400 could store and launch at least two attack aircraft armed with one torpedo or 800 kg (1,800 lb) bomb. Obviously the technology level of Japan was very high during the early 1940s.