Researchers in Hawaii find lost Japanese WWII mega-sub
December 4, 2013 -- Updated 0029 GMT (0829 HKT)
- 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
Today's five most popular stories
Part of complete coverage on
September 30, 2014 -- Updated 1550 GMT (2350 HKT)
Experts believe that ISIS may be using a Spanish enclave to bring jihad to Europe.
September 30, 2014 -- Updated 1300 GMT (2100 HKT)
With an efficient subway, inexpensive taxis and a good public bus system, Hong Kong is normally an easy city to navigate ...
September 28, 2014 -- Updated 2332 GMT (0732 HKT)
CNN's Ivan Watson was in the middle of a pro-democracy protest in Hong Kong when things got out of hand.
September 30, 2014 -- Updated 1353 GMT (2153 HKT)
The world's animal population has halved in 40 years as humans put unsustainable demands on Earth, a new report warns.
September 30, 2014 -- Updated 1249 GMT (2049 HKT)
Every day, refugees and migrants risk their lives as they seek a new life. Now, a new report puts a figure to the number of victims.
September 30, 2014 -- Updated 1442 GMT (2242 HKT)
Mainstream commentators must promote positive role models to Muslims feeling victimized, writes Ghaffar Hussain.
September 29, 2014 -- Updated 0613 GMT (1413 HKT)
Two men familiar with inside knowledge of ISIS speak with CNN's Arwa Damon.
Explore CNN's interactive that explains ISIS' roots, what it controls, and where its support comes from.
September 25, 2014 -- Updated 2010 GMT (0410 HKT)
In his first-ever interview as the Emir of Qatar, Sheikh Tamim bin Hamad Al-Thani defended his country against allegations of funding terrorism.
September 27, 2014 -- Updated 1503 GMT (2303 HKT)
The North Korean leader hasn't been seen for weeks, leading to speculation that he is in poor health.
September 24, 2014 -- Updated 0154 GMT (0954 HKT)
Haider al-Abadi hopes airstrikes don't lead to "of another terrorist element" instead of ISIS.
September 25, 2014 -- Updated 1319 GMT (2119 HKT)
The United States couldn't do it on its first try. Neither could the Soviets.
September 24, 2014 -- Updated 1529 GMT (2329 HKT)
CNN's Nima Elbagir reflects on a harrowing trip to Liberia where she covered the deadliest Ebola outbreak in history.
September 26, 2014 -- Updated 1423 GMT (2223 HKT)
Contrary to public opinion, rats can actually save lives -- Apopo's rats have actually saved thousands.
September 30, 2014 -- Updated 1336 GMT (2136 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.