High Quality Content by WIKIPEDIA articles! The Type 93 (designated for Imperial Japanese calendar year 2593) was a 61 cm (24 in)-diameter torpedo of the Imperial Japanese Navy (IJN). It is commonly referred to as the "Long Lance" torpedo by most modern English-language naval historians, a nickname being given after the war by Samuel E. Morison, the chief historian of the U.S. Navy, who spent much of the wartime in the Pacific Theater. The "Long Lance" was by far the most advanced naval torpedo in the world at the time. The Type 93's development (in parallel with a submarine model, the Type 95) began in Japan in 1928, under the auspices of Rear Admiral Kaneji Kishimoto and Captain Toshihide Asakuma. At the time, by far the most powerful potential enemy of the Japanese Navy was the United States Navy's Pacific Fleet.