April 1st Joke ?

Have you heard the joke about the Japanese submersible aircraft carriers which were supposed to sneak up to the US coast and then catapult their bombers into the air to wreak havoc on American cities? Nope? Read on – it’s not a joke.

Two Japanese submarines designed to carry bomber aircraft to launch attacks on American cities during the Second World War have been found on the sea bed off the coast of Hawaii. The vessels were captured by the United States Navy when Japan capitulated in 1945, but were hastily scuttled the following year when the Soviet Union demanded access to the vessels. The US had learned many technological secrets from the I-14 and I-201 submarines and did not want the information falling into the hands of its Cold War enemy.

Designed as underwater aircraft carriers, they were able to stow three Aichi light bombers, with folded wings, in a hangar on the deck. The aircraft were designed to be catapulted from the deck and were fitted with floats to allow them to land on water once they returned from their missions.

Aware of its inferiority in surface ships in the Pacific theatre, the Japanese Navy wished to take the fight to the enemy and the I-201 was given the task of approaching the US coast, surfacing, preparing and launching its aircraft within minutes. One of the earliest missions called for the aircraft to drop rats infected with bubonic plague and insects carrying cholera, dengue fever, typhus and other diseases on cities on the West coast of America. Five submarines were captured by the US in total and sent to Hawaii for inspection.

But in 1946, as the Soviet Union began showing an interest, the vessels were sunk by torpedoes from the USS Cabezon and sank almost 2,700ft off Oahu. The I-401 was the first to be located, in March 2005, but it has taken a further four years to locate her sister boat.

The I-14 carried enough fuel to travel 37,000 miles – or around the world one-and-a-half times – and was three times the size of other submarines of the time. It had a crew of 144, displacement of 5,223 tons and a maximum operating depth of 330ft.

Each of the Aichi Seiran bombers – whose existence was unknown to Allied intelligence – was able to carry an 800kg bomb over a distance of 650 miles at a speed of 295mph. A crew of four could ready the aircraft in 45 minutes after it emerged from the hangar on the deck and before it was launched from a 120-foot catapult on the deck.