Subs could surface & assemble bomber aircraft in minutes.
Marine archaeologists have found two World War II era Japanese attack submarines near Pearl Harbour, decades after they were sunk by the US navy to keep their revolutionary technology away from the Soviets, who were demanding access after the war.
During WWII, the Japanese designed these submarines as the ultimate stealth weapon; they could pop up, assemble and launch bomber aircraft within minutes and then submerge. They were almost certainly built to target the critical US East Coast cities of New York and Washington as well as Panama further south. Fortunately for the Americans, WWII ended before these subs could be used, as they were developed late in 1944 and in small numbers. In fact, up to five of these subs were part of the Japanese fleet that fell into US hands after the war. They were towed to Pearl Harbour for inspection. Later, the US, chary of sharing the advanced technology used with the Soviets, scuttled the subs south of Oahu outside Hawaii without bothering to record the exact location.
Archaeologist Terry Kerby of the Hawaii Undersea Research Laboratory has looked for these submarines in manned submersibles since 1992. One, the I401, was found in 2005 and two more (the I14 and I201) were discovered this year. Two more remain missing, the I400 and the I203; the former is supposed to be one of the largest non nuclear submarines ever built.
Each sub kept up to three aircraft in a watertight hanger, each of which could be armed with 1800 lb bombs. Part of Japan's Sen Taka class, these were the fastest submarines on earth in their time, zipping along underwater at 22 knots. They could also dive deeper than any other Japanese submarine and stay underwater for up to a month. Conventional features included retractable deck guns, retractable diving planes and a sleek profile for speed.
The submarines were designed to carry and launch folding wing plane bombers by catapult within minutes after surfacing and dive underwater immediately. Experts say that the I14 could go 37,500 miles, or one and half times around the earth, without refuelling and then launch its bombers. The largest I400 submarines were 400 feet long with technology that was way ahead of the time. Nobody on earth had that kind of long range capability until the era of nuclear submarines and intercontinental ballistic missiles much later.
The US National Oceanic and Atmospheric Administration's Van Tilburg says that these samurai subs now belong to the ocean and that people should protect them as they would protect reefs and wildlife. "It is a very fitting place for them. It's dark and quiet, it's deep and cold. They can rest there for quite a while," he told the National Geographic.