Japanese were planning attack on Panama Canal in the final days of WWII

LARRY C. BOWERS Banner Staff Writer
Posted 12/7/15

Here’s a little more “infamy” from the history of World War II in the Pacific, which almost brought the war to mid-America.

In the final days of the war, according to historians, the …

This item is available in full to subscribers

Japanese were planning attack on Panama Canal in the final days of WWII


Here’s a little more “infamy” from the history of World War II in the Pacific, which almost brought the war to mid-America.

In the final days of the war, according to historians, the Japanese were considering a plan to attack the Panama Canal, the primary route for America’s transport of troops and supplies from the east coast of the U.S. to the Pacific Theater.

A similar plan had been drawn up at the start of the war, when the Japanese attacked Pearl Harbor, but the campaign was called off. The revived plan was put together later as Japan was building a group of super submarines, underwater aircraft carriers which housed three suicide bombers each.

At the end of May 1945, according to historical documents, final preparations for a secret mission were taking place at the aerial operations division of Imperial Japanese Headquarters.

The secret operation was intended to shatter confidence among those in the U.S., much like the raid on Pearl Harbor. It was a bombing raid on the Panama Canal, which would curtail the waterway’s access to the Pacific.

If it had been successful, the U.S. would have been forced to send troops and supplies overland to the West Coast, or south around South America.

The plan was born right after the Doolittle Raid on the main island of Japan, the first U.S. raid on Tokyo in April 1942. After that, Japanese strategists were determined to launch a counterstrike against America.

At the instigation of Admiral Yamamoto, a series of 15 giant Class I-400 submarines were ordered, each able to carry three special-duty aircraft. These 5,223-ton submarines, with a range of 37,500 nautical miles, were twice as large as the largest vessels in the U.S. Navy, and could remain at sea for four months without refueling.

A catapult stretched from the spacious cylinder-shaped hangar in the starboard hold, forward to the bow.

The aircraft built to take off from the submarines were twin-seater Aichi M6A1 Seiran seaplanes, specially designed for the Panama Canal operation. The Seirans were all equipped with German Daimler-Benz 400 horsepower engines and were designed as the world's first “throwaway airplanes.” They would drop off the crew after the raid, be ditched from the submarine, and sink at once.

To help ensure that the raid on the Panama Canal came as a surprise, the Japanese planned to attack not from the east, but from the Caribbean Sea to the west. Four submarine aircraft carriers would launch their 12 aircraft shortly before daybreak.

A 25-year-old pilot, Lt. Atsushi Asamura, was assigned to lead the operation, which was planned for mid-July 1945. The plan was to drop bombs and torpedoes on the canal gates and the nerve-centers of the Panama Canal.

As soon as the crews had been taken back on board and the aircraft sunk, the submarine motherships would submerge as rapidly as possible.

The Seiran unit was formed on Dec. 15, 1944, and was officially known as the 613th Air Corps. It’s commander was a Capt. Arizumi, an officer of the 1st Japanese Submarine Flotilla to which the giant submarines belonged.

The new unit was under the overall command of the 6th Fleet in Kure. Two of the best-known members of the newly formed Seiran Corps were officers Nobuo Fujita and Shoji Okuda. Both had been involved in the first and only previous air raid on the U.S. That attack was from Submarine I-25 on Sept. 9, 1942. A Yokosuka E14Y1 was used on that raid, a direct ancestor of the Seirans, according to historical documents.

That 1942 raid in Oregon was an attempt to start a wildfire on the West Coast. Bombs were dropped into the forest, but caused limited damage.

The I-25 submarine was later destroyed by the American Destroyer USS Patterson off New Hebrides on Sept. 3, 1943,

exactly one year from the raid on the Oregon forest. Fujiti and Okuda had previously left the submarine.

The Oregon raid marked the only time during World War II that an enemy plane dropped bombs on the United States mainland.

The Seiran and submarine crews began preparation exercises on April 2, 1945. It was determined that 1,760 pounds was the heaviest bomb load the Seirans could risk carrying on their catapult takeoff. The hangers had been camouflaged with dummy chimneys to disguise the huge submarines from U.S. reconnaissance planes.

On June 25, 1945, Imperial Japanese Headquarters halted preparations for the Japanese attack on the Panama Canal, and issued new orders.

In view of the American threat to the Japanese islands, the 12 Seiran aircraft were ordered to find a suitable opportunity to launch a kamikaze raids (Operation Hikari) against U.S. aircraft carriers; but the Japanese surrender came before the operation was carried out.

With these rapid changes at the end of the war, and a change of plans at the start of the war in the Pacific, the Panama Canal was spared.


No comments on this story | Please log in to comment by clicking here
Please log in or register to add your comment


Print subscribers have FREE access to clevelandbanner.com by registering HERE

Non-subscribers have limited monthly access to local stories, but have options to subscribe to print, web or electronic editions by clicking HERE

We are sorry but you have reached the maximum number of free local stories for this month. If you have a website account here, please click HERE to log in for continued access.

If you are a print subscriber but do not have an account here, click HERE to create a website account to gain unlimited free access.

Non-subscribers may gain access by subscribing to any of our print or electronic subscriptions HERE