Skip to main content

Researchers in Hawaii find lost Japanese WWII mega-sub

By Michael Pearson, CNN
December 4, 2013 -- Updated 0029 GMT (0829 HKT)
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
September 17, 2014 -- Updated 1239 GMT (2039 HKT)
Sean Connery says "yes," whilst David Beckham says "no." See what the famous are saying about Scotland's referendum.
September 17, 2014 -- Updated 1710 GMT (0110 HKT)
On September 18, Scots go to the polls to vote on the future of their country. Here's what you should know.
September 17, 2014 -- Updated 1720 GMT (0120 HKT)
This is "Flames of War," a slick and ominous new video from the ISIS media center.
September 16, 2014 -- Updated 1903 GMT (0303 HKT)
For years, Morten Storm moved between two worlds. A radical Islamist turned double agent is lifting the lid on some of the world's best-kept secrets.
September 17, 2014 -- Updated 0038 GMT (0838 HKT)
A man abducted alongside killed U.S. journalist Steven Sotloff tells CNN that no one from the U.S. government has tried to talk with him.
September 17, 2014 -- Updated 1508 GMT (2308 HKT)
Mulatu Astatke is the founding father of ethio-jazz: a fusion of Ethiopian music with western jazz.
September 17, 2014 -- Updated 1311 GMT (2111 HKT)
Have you been to these? The global museum list, released Tuesday, ranks 25 of the world's best museums.
September 17, 2014 -- Updated 1703 GMT (0103 HKT)
iOS 8, the latest version of Apple's mobile operating system, comes with new features that you'll enjoy.
September 16, 2014 -- Updated 1253 GMT (2053 HKT)
The Ebola virus, very deadly and currently without a cure, is fast-spreading throughout the small West African country.
September 17, 2014 -- Updated 1213 GMT (2013 HKT)
It's a surfer's paradise -- but Diah Rahayu is out on her own when it comes to professional women's wave-riding in Bali.
September 17, 2014 -- Updated 1004 GMT (1804 HKT)
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