Skip to main content

Researchers in Hawaii find lost Japanese WWII mega-sub

By Michael Pearson, CNN
updated 7:29 PM EST, Tue December 3, 2013
STORY HIGHLIGHTS
  • Researchers find the remains of an advanced submarine sunk by the U.S. Navy in 1946
  • The I-400 was essentially an underwater aircraft carrier
  • The Soviet Union wanted to inspect the sub's advanced technology
  • The sub represented a big shift in submarine tactics, a researcher says

(CNN) -- Researchers in Hawaii have found a mammoth World War II-era Japanese submarine scuttled by the U.S. Navy in 1946 to keep its advanced technology out of the hands of the Soviet Union.

The Hawaii Undersea Research Laboratory at the University of Hawaii discovered the I-400 in 2,300 feet of water off the southwest coast of Oahu, according the school.

"Finding it where we did was totally unexpected," lab operations director and chief submarine pilot Terry Kerby said in a university statement. "All our research pointed to it being further out to sea."

Piece of Civil War ironclad brought to surface in Savannah

At nearly 400 feet long, the I-400 and its two sister ships were the largest submarines ever built before the nuclear age.

Initially conceived as a weapon to target the U.S. mainland and capable of reaching any point on the globe without refueling, the subs were effectively underwater aircraft carriers outfitted with three folding-wing seaplanes capable of carrying an 1,800-pound bomb.

The ships were never used to attack the mainland United States and saw only limited service before Japan surrendered in 1945.

But their novel design represented a tactical shift in thinking about the use of submarines, which until then had been strictly seen as anti-ship weapons, James Delgado, director of the Maritime Heritage Program of the National Oceanic and Atmospheric Administration, said in the university statement.

Shipwreck hunters stumble across mysterious find

"Following World War II, submarine experimentation and design changes would continue in this direction, eventually leading to ballistic missile launching capabilities for U.S. submarines at the advent of the nuclear era," Delgado told the university.

The submarine was found in August, but the laboratory didn't notify the public until after informing the U.S. State Department and the Japanese government, the university said.

The I-400 was one of five Japanese submarines captured by the U.S. Navy at the end of World War II and sent to Hawaii for examination, the school said.

With tensions rising between the Soviet Union and the United States after the war, the Navy scuttled the ships to avoid their advanced technology falling into the hands of the Soviet navy in what would become one of the first intrigues of the Cold War.

The Hawaii Undersea Research Laboratory has so far found four of the ships.

Pearl Harbor survivor, 91, helps identify unknown dead

ADVERTISEMENT
Part of complete coverage on
updated 4:09 PM EDT, Tue September 23, 2014
The U.S. and several Arab nations carried out airstrikes against ISIS in Syria, intensifying the campaign against the militant group.
updated 8:18 AM EDT, Tue September 23, 2014
Her friends were raped and her brother was killed by ISIS, but 15-year-old "Aria" managed to escape.
updated 6:58 AM EDT, Tue September 23, 2014
Emma Watson lent her name and her glittery profile to the cause of feminism at the United Nations.
updated 9:06 PM EDT, Mon September 22, 2014
From Gadhafi to Ahmadinejad, Bush to Chavez: look back at memorable moments from past UNGA sessions. Richard Roth reports.
updated 3:41 AM EDT, Tue September 23, 2014
Just days after NASA's Mars orbiter reached the Red Planet, India's first mission could follow suit and make history.
updated 4:14 PM EDT, Tue September 23, 2014
Khorasan, al Qaeda's new branch, seeks new ways to attack America and Europe.
Alibaba officially became the biggest initial public offering of all time, confirming that in the final tally it raised $25 billion.
updated 10:57 PM EDT, Mon September 22, 2014
Do the Chinese really like to mix their Bordeaux with Coca-Cola?
updated 5:36 AM EDT, Tue September 23, 2014
Cape Town native, Janine Davies is South Africa's first female rider to compete on a national level.
In the largely male-dominated world of the motorsport, South African super bike racer Janine Davies is an anomaly.
updated 7:30 AM EDT, Tue September 23, 2014
The Lilongwe Wildlife Center houses over 200 animal victims and helps rehabilitate them back into the wild.
updated 6:52 AM EDT, Tue September 23, 2014
Each day, CNN brings you an image capturing a moment to remember, defining the present in our changing world.
Browse through images from CNN teams around the world that you don't always see on news reports.
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT