Japan's WWII Midget Sub

  • By Parks Stephenson
  • Posted 12.01.09
  • NOVA

During WWII, the Japanese Navy deployed hundreds of different sorts of submarines, but on December 7th, 1941, they debuted a particularly secret weapon—the Type A Ko-Hyoteki midget sub. Five furtively made their way toward Pearl Harbor to attack U.S. battleships. At a quarter the size of common fleet subs, the midgets were a technological marvel, far outperforming their western counterparts. Here, explore a model.

Launch Interactive

A 3-D model offers a detailed look at the tiny submarine that carried torpedoes into Pearl Harbor.

Parks Stephenson is a Systems Engineering Manager at Lockheed Martin Maritime Systems and Sensors. He has also been a contributing member of the Marine Forensic Panel and a historical advisor to various documentary films, including James Cameron's Ghosts of the Abyss. For more on Stephenson as well as in-depth information on the fifth Japanese midget sub, visit his website, i-16tou.com.


Melissa Salpietra
Tyler Howe
Dan Hart


(computer generated sub images)
© Parks Stephenson
Courtesy Yokohama Radio Museum
(archival photo of net cutter)
Courtesy Naval History and Heritage Command
(archival photos of the forward and aft battery rooms, batteries, conning tower, control room, motor room, propeller, pulley, tail assembly, torpedoes, torpedo room)
Courtesy U.S. National Archives files "Description and Photographs of Japanese Submarine No. 19"

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