Japanese submarine I-401
Encyclopedia
The Sen Toku-class
I-400 class submarine
The Imperial Japanese Navy submarines were the largest submarines of World War II and remained the largest ever built until the construction of nuclear ballistic missile submarines in the 1960s. They were submarine aircraft carriers able to carry three Aichi M6A Seiran aircraft underwater to their...
I-401 was once the largest submarine in the world. It was commanded by Lieutenant Commander
Lieutenant Commander
Lieutenant Commander is a commissioned officer rank in many navies. The rank is superior to a lieutenant and subordinate to a commander...
Nobukiyo Nambu of the Imperial Japanese Navy during World War II. Capable of carrying three two-seat Aichi M6A
Aichi M6A
The Aichi M6A Seiran was a submarine-launched attack floatplane designed for the Imperial Japanese Navy during World War II...
1 "Seiran" (Mountain Haze) float torpedo bomber
Torpedo bomber
A torpedo bomber is a bomber aircraft designed primarily to attack ships with aerial torpedoes which could also carry out conventional bombings. Torpedo bombers existed almost exclusively prior to and during World War II when they were an important element in many famous battles, notably the...
s, the Sen Tokus were built to launch a surprise air strike against the Panama Canal
Panama Canal
The Panama Canal is a ship canal in Panama that joins the Atlantic Ocean and the Pacific Ocean and is a key conduit for international maritime trade. Built from 1904 to 1914, the canal has seen annual traffic rise from about 1,000 ships early on to 14,702 vessels measuring a total of 309.6...
.
Service history
When the I-401 was completed and commissioned on January 8 1945 in the Kure Naval District, the Second World WarWorld War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
was almost over. This left the fate of I-401 uncertain. After several attempts to launch, the I-401 set course for its first target, but was stopped by Emperor Hirohito
Hirohito
, posthumously in Japan officially called Emperor Shōwa or , was the 124th Emperor of Japan according to the traditional order, reigning from December 25, 1926, until his death in 1989. Although better known outside of Japan by his personal name Hirohito, in Japan he is now referred to...
's broadcast, calling for an end to all hostilities on August 15 1945.
On August 26 1945, the I-401 hoisted a black flag of surrender. Its unmanned planes were catapulted into the sea, all 20 Type 95 torpedo
Type 95 torpedo
The Type 95 torpedo was a torpedo of the Imperial Japanese Navy.It was based on the formidable Type 93 torpedo but had a smaller warhead, shorter range and a smaller diameter...
es were destroyed, and all codes, logs, charts and secret documents were also destroyed.
Three days later, on August 29 1945, the I-401 was picked up on 's radar. I-401 surrendered to the American ship. Lieutenant Commander Nobukiyo Nambu delivered two samurai swords, as a symbol of surrender, to Lieutenant
Lieutenant
A lieutenant is a junior commissioned officer in many nations' armed forces. Typically, the rank of lieutenant in naval usage, while still a junior officer rank, is senior to the army rank...
J.E. Balson, the Segundos Prize Crew officer.
The I-401 was finally sunk, when used as a target ship, off Pearl Harbor
Pearl Harbor
Pearl Harbor, known to Hawaiians as Puuloa, is a lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. Much of the harbor and surrounding lands is a United States Navy deep-water naval base. It is also the headquarters of the U.S. Pacific Fleet...
on May 31, 1946.
Rediscovery
On March 17 2005, the Hawaii Undersea Research LaboratoryHawaii Undersea Research Laboratory
The Hawaii Undersea Research Laboratory is a regional undersea research facility under the auspices of the U. S. government's National Oceanic and Atmospheric Administration National Undersea Research Program and administered by the University of Hawaii. Its headquarters are at University of...
's (HURL) deep-diving submersibles Pisces IV & Pisces V
Pisces V
Pisces V is a deep-submergence vehicle of the Pisces class built in 1973.Pisces V is type of manned submersible ocean exploration device, powered by battery, and capable of operating to depths of 2000 m , a depth that is optimum for use in the sea waters around the Hawaiian Islands...
located the I-401 off the coast of Kalaeloa
Kalaeloa, Hawai'i
Kalaeloa is a census-designated place in Honolulu County, Hawaii, United States. The population was 67 at the 2000 census. The community occupies the location of the former Naval Air Station Barbers Point, which was closed in 1999 and subsequently transferred to the State of Hawaii...
. The I-401 lies about 820 meters (2665 feet) off the coast of Barbers Point. The bow
Bow (ship)
The bow is a nautical term that refers to the forward part of the hull of a ship or boat, the point that is most forward when the vessel is underway. Both of the adjectives fore and forward mean towards the bow...
is broken off just forward of the aircraft hangar. The two pieces are not far apart and are connected by a debris
Debris
Debris is rubble, wreckage, ruins, litter and discarded garbage/refuse/trash, scattered remains of something destroyed, or, in geology, large rock fragments left by a melting glacier etc. The singular form of debris is debris...
field. The main hull is sitting upright on the bottom, the numbers "I-401" are clearly visible on the sides of the conning tower
Conning tower
A conning tower is a raised platform on a ship or submarine, often armored, from which an officer can con the vessel; i.e., give directions to the helmsman. It is usually located as high on the ship as practical, to give the conning team good visibility....
. Her 25 mm antiaircraft guns seem in almost perfect condition.