Airfield under the sea

4th June 2012, 13:42

In many ways HIJMS I-400 was decades ahead of her time. She was the world’s largest submarine with a length of 400-ft and a surface displacement of 3,530 tons. Above her main deck rose a 115-ft. long, 12-ft diameter, hangar housing three torpedo-bombers. These float
planes were rolled out through a massive hydraulic door onto an 85-ft pneumatic catapult, where they were rigged for flight, fueled, armed, launched,and after landing alongside, lifted back aboard with a powerful hydraulic crane. The I-400 was equipped with a snorkel, radar, radar detectors, and capacious fuel tanks that gave her a range of37,500 miles: One and a half times around the world. She was armed with eight torpedo tubes, a 5.5-in 50-cal deck gun, a bridge 25mm antiaircraft gun, and three triple 25 mm A/A mounts atop her
hangar. The advent of guided missiles and atomic bombs transformed her from dinosaur to an overspecialized undersea menacing strategic

Here is the Link:

Now if you'd care to read about how the US Navy picked up these "Beast of Burden" here is another article providing the details.

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donald h
4th June 2012, 14:41
Very interesting links, Bud.
I have certainly not come across these before in any of my history books!!


4th June 2012, 15:03
Hi Donald.....well I attempt to produce articles that are somewhat "off the beaten path".....I don't always accomplish this endeavor.....but I try to give it a go. But it is all true.....
My purpose of my articles are to generate thoughts, discussion, and comments....makes for super interesting least that is my opinion.

Hope y'all enjoy.

4th June 2012, 16:11
During World War Ii the Japanese built the largest submarines in the world, not exceeded in size until the advent of the nuclear ballistic missile subs of the 1960s. Some included hangers and catapults for use by scout planes. In the case the I-400 class, however, the aircraft to be accommodated were intended to be larger planes, specially designed for an attack on the Panama Canal.

Unfortunately, however, like most of the large diesel-powered submarines of that period, Japan's giant subs they were sluggish to maneuver underwater. They were also slower to submerge than normal sized submarines, which made them. As a result, they proved more vulnerable to attack by aircraft and destroyers then smaller, handier submarines.

4th June 2012, 16:24
The cruise to attack the Panama Canal was proceeding according to plan until Technician Third Class, Aiko Hashimoto, having replaced an aircraft fuel pump, decided to carry out an engine run whilst submerged. (Jester)

Very interesting concept, making use of the technology of the time for an attack on a specific target; a bit like the Dambusters contrivance.

John Rogers
4th June 2012, 16:25
Thats one hell of a weapon system. Great article Bud, thanks for posting it.

4th June 2012, 16:25
Excellent info........Love how the articles stimulate comments from others that has knowledge to share..... Thanks to all for taking the time to do so.