Japan needed a larger boat able to oppose craft such as the American Elco PT boat. The Type 51 began with a rough sketch of a Schnellboot and a privately owned boat from the same German builder. Proper German drawings arrived later, but Japan lacked the same experience in mixed-material small-boat construction and the same fabrication methods. Adapting the design to local techniques created further problems that required more alterations. The resulting boat resembled a Schnellboot in outline while differing substantially in construction. The alternative proposed here was to enlarge and improve the Type 14 around methods Japanese yards already knew.
Notable Point · 1:20:57-1:24:01
Why Japan's Type 51 was not a German Schnellboot
German drawings could not supply the manufacturing experience needed to reproduce a Schnellboot in Japanese yards.