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IN THE SCHOOL OF OCEAN AND EARTH SCIENCE AND TECHNOLOGY AT THE UNIVERSITY OF HAWAI'I AT MANOA

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SUB-7b: IJN I-401 (main body)

Composite: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodySurvey: I-401 main bodyHistoric photo: I-401 alongside tenderHistoric photo: Captain Kijiro NambuHistoric photo: I-400 dry dock sternHistoric photo: I-400 dry dockHistoric photo: I-400 14 cm deck gunHistoric photo: I-400 class at seaHistoric photo: I-400 tailHistoric photo: I-400 with USS EuryaleHistoric photo: I-401 Binoculars-Bowfin MuseumHistoric photo: I-401 conning tower


HURL Artifact No. SUB-7b *Denotes approximations and speculations
Name: I-401 (main body) Lost: 31-May-1946
Artifact Type: Submarine Found: 17-Mar-2005
Nationality: Japanese Dive No: PV_608/PIV-136
Class or Make: I-400 Location: Barber's Pt.
Model: Sen Toku Depth (m): 811m
Purpose: Long range, Aircraft HURL crew: M. Cremer, S. Price, J. Smith/T. Kerby, C. Wollerman
Serial Number: n/a Additional Dives: PIV-158, PIV-211
Built/Launched: 3/11/1944; Sasebo Naval Yard, Japan
Length: 300' (400.3')
Width: 39.3'
Height: 23'
Circumstance of Loss: Sunk as target by torpedo (By USS Cabezon SS-334) Crew Personnel/Position: 157 Officers and Men (In some cases, excess of 200)
Reason of Loss: Test Mk 18 torpedo exploder *Prevent foreign intelligence gathering Crew Survivals/Fatalities: Capt. T. Ariizumi (SubDiv 1 Cdr); (Committed suicide prior to arrival in Japan)
Artifact History: Originally built to attack Gatum Locks at the Panama Canal. Later plan was change to attack the fleet at anchor in Ulithi Atoll. A rendezvous was missed and the war ended before the attack could be made. Sub was captured at sea by the USS Segundo SS-398 enroot to Japan. Later it was taken to Oahu and studied by Navy Intelligence and finally sunk in a torpedo exercise.
Artifact Condition: Main body is sitting upright. Wood on deck is depleted giving internal view of free flood area. Deck gun on back deck is in pristine condition and pointing stbd. Entire hangar bay is missing. Conning tower remains in good condition, although stripped.
Additional Information: Submarine weighed 6,560 tons, had 4 diesel engines, a range of 37,500 miles @ 14kts, could make 6.5 kts submerged and 18.75 kts on the surface. It had a hanger by that would house 3 Aichi Seiran aircraft. Maximum operational depth was 330'. Armament consisted of 8 torpedo tubes, 20 torpedoes, (1) 14cm deck gun, 1 single and 3 triple 21mm anti-aircraft guns. There were 3 Sen Toku submarines built and they were the largest submarines in the world until 1965. The lazy figure eight hull configuration may have inspired the Russian Typhoon class submarines built 40 years later.