Japan's Secret Underwater Aircraft Carriers: The I-400 Submarines

🚢Japan developed the I-400 submarines, the world's largest submarines and a new kind of weapon.

🛫The I-400 submarines could launch torpedo dive bombers and were intended to bring the war directly to America's cities.

🌊The submarines had a double hull design and were nearly twice the length of a typical German U-boat.

🕒Launching the torpedo dive bombers from the submarines took around 30 minutes, making it a time-consuming and risky operation.

🇺🇸The I-400 submarines were never used in combat and were scuttled after Japan's surrender.

Were the I-400 submarines successful?

—No, the I-400 submarines were never used in combat and did not have the opportunity to prove their effectiveness.

Why were the I-400 submarines scuttled?

—The I-400 submarines were scuttled to prevent the Soviets from inspecting them after Japan's surrender.

What was the purpose of the I-400 submarines?

—The I-400 submarines were intended to launch surprise attacks on American cities and force the United States into negotiating a truce.

How many I-400 submarines were built?

—Only five I-400 submarines were built, and only three of them were completed.

What happened to the I-400 submarines?

—The I-400 submarines were scuttled off the coast of Hawaii and Japan, and their wreckage locations were kept secret.

00:25In August of 1945, the US Navy intercepted a Japanese submarine, the I-400, which turned out to be the world's largest submarine and an entirely new kind of weapon.

02:39The I-400 submarines were intended to launch torpedo dive bombers and bring the war directly to America's cities.

04:46The I-400 submarines had a double hull design and were nearly twice the length of a typical German U-boat.

05:55Launching the torpedo dive bombers from the submarines took around 30 minutes and was a time-consuming and risky operation.

07:40The I-400 submarines were never used in combat and were scuttled after Japan's surrender.