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Fu-Go “fire-bomb” balloons — HBC manager sights Japanese balloon falling from the sky near Oxford House outpost
Jun 13, 2013

 

by Bruce Cherney
The manager of the Hudson’s Bay Company post at Oxford House, Manitoba, 560 kilometres northeast of Winnipeg, watched in amazement as an object fell from the sky. He rushed to the scene about 15 kilometres from the HBC post where he discovered the object was one of the most bizarre and patently absurd “terror” weapons developed by the enemy during the Second World War. 
After travelling thousands of kilometres over the Pacific Ocean, a bomb-laden balloon had plopped down in the bush in the middle of the North American continent.
The December 1945 issue of the Beaver magazine, then published by the Hudson’s Bay Company (HBC), which was recently renamed Canada’s History and is now published by the Canada’s History Society, was the first publication  to report the incident.
Quoting the Beaver article, the Winnipeg Tribune on December 18, 1945, said the balloon that originated in Japan landed near Oxford House the previous April.
“As it was the first one to be found so far east,” reported the then quarterly magazine, “no arrangements had been made in that area by the authorities for the reporting and control of these deadly objects.
“However, the post manager very diplomatically sent a code message to the (HBC’s) head office in Winnipeg, at the same time putting Indian guards on the balloon and attachments until he received further radio instructions.
“Head office speedily turned the matter over to the military authorities, and much radio traffic passed between Winnipeg and Oxford House, before the balloon and its bomb were taken over by the proper authorities.”
The Japanese referred to their Fusen Kakudan, which literally means “balloon bomb,” as Fu-Go, with Fu being the first character for the Japanese word for balloon (Fusen). Go is numerical, and thus the balloons were designated Weapon No. 32 of the Japanese Ninth Army Technical Research Laboratory.
According to Robert C. Mikesh, author of Japan’s World War II Balloon Bomb Attacks on North America (Smithsonian Institution Press, 1972), the balloons were the Japanese’s response to the April 1942 Doolittle Raid, when 16 B-25 Mitchell twin-engine bombers launched from the USS Yorkton aircraft carrier dropped bombs on the island nation. The damage inflicted on Japan was minimal — it was meant more as a psychological blow against the Japanese and a morale boast to the American public — but the Japanese military dictatorship lost “face,” which prompted the two-year project to research and design a balloon weapon to strike back at the U.S. 
The 10-metre (32.8-foot) diameter balloons were made of a type of paper made from the common Japanese kozo (mulberry) bush and gas-proofed with vegetable oil made from a type of Japanese potato, and were assembled by hand, usually by schoolgirls. Since Japan was in the midst of a food shortage, it was not uncommon for the workers to steal the powder used to make the paste sealant, as it was a viable food substance.
Another version of the balloon envelop was made from silk that was coated with a gum (B-type Rubberized-silk Balloon).
Suspended under the balloon envelop was an aluminum ring, about a metre across, which supported a control and ballast system and the bomb load (Paper Threat: The First Intercontinental Weapon System: Japanese Fu-Go Balloons, by Joel Carpenter, Project 1947). “Around the rim of the ring was a series of 32 ‘blow-out plugs,’” wrote Carpenter, “similar to explosive bolts. Each plug supported a ballast sandbag.”
Partially filled with hydrogen, the balloons were launched from several sites on the Island of Honshu, the Japanese main island. The balloons climbed to 9.5 kilometres (30,000 feet) to enter a current of high-speed wind (jet stream) that would take them west across the Pacific. When the balloons dropped below a “predetermined minimum altitude, barometric switches would snap closed, energizing circuits to the blowout plugs. A pair of ballast bags would be cut free, and the Fu-Go, lightened, would begin to climb back into the high-altitude windstream.”
If the balloon went too high, a valve opened to let hydrogen escape.
This process was repeated until the balloon traveled the 9,000 kilometres to reach North America and then released its cargo of bombs. With the aid of the fast-moving jet stream, it took just three days from a balloon’s launch in Japan to reach North America.
“When all 32 sand bags were expended, the balloon would discharge its load of bombs,” wrote Mikesh.
“As a final step, a flash-bomb attached to the balloon was supposed to detonate,” explained Carpenter, “incinerating the evidence and adding to the mystery of the device’s origin.”
The Japanese had planned to launch 10,000 of these devices. After the war, Japanese authorities admitted to the Allies that they launched 9,300 Fu-Go balloons between 1944 and 1945. The first balloons were sent skyward on November 3, 1944.
At this time, the USAF was beginning its bombing campaign of Japanese targets using B-29 Superfortresses. The first bombing missions were ineffectual as they were undertaken at high altitudes, and as a result, the jet stream scattered the bombs about so that most missed their targets (the estimate is that only five per cent came anywhere near the intended target). In addition, bombers caught in the jet stream were virtually standing still in the 320-km/h headwind, and were thus became easy targets for anti-aircraft fire from the ground. 
But when General Curtis LeMay, the commander of the XXI Bomber Command in the Pacific Theatre of Operation, ordered a change to from daytime high-level bombing to nighttime low-level strikes using incendiary bombs, whole sections of Japanese cities were easily set ablaze.
Teiji Takade, one of the scientists with the Fu-Go project, recalled that the bombardment by the USAF and the flames of conflagration sweeping the island nation resulted in the hope that the same destruction would be inflicted on “the enemy country” when the balloons were initially launched (Mikesh).
By December 1944 and January 1945, the first inklings of strange sightings were reported to military authorities. Balloons were sighted over the Pacific Ocean off the North American coast, while others were seen floating over the continent. But it wasn’t until officials recovered intact balloons that the Fu-Gos were determined to be weapon systems.
Still, no one at first believed the balloons had come directly from Japan. Some believed they were launched from submarines, which was too impractical given the high number of balloons. Another wild theory had the balloons launched from prisoner of war camps in North America by Japanese or German inmates.
The launch sites remained a mystery until geologists determined that the sand used in the balloon’s ballast came from beaches on Honshu, the main Japanese island. With the help of Canadians, who were also testing sand from balloons that landed north of the border, the U.S. military further narrowed down the location of launch sites, but the balloon offensive ended before this information was of any practical benefit.
From the onset of the balloon offensive, American and Canadian authorities tried to keep the fact that the mainland was being subjected to enemy air attack under wraps to prevent the public from panicking. 
Another more compelling reason to remain quiet about the balloons was to prevent the Japanese from getting wind, through either radio broadcasts or newspaper reports, about the effectiveness of the bombing — information that could have been used “to evaluate and improve their techniques” (Mikesh).
Yet another reason for the censorship was that the U.S. military initially believed that the balloons may be designed to carry biological or possibly chemical weapons. The basis for this fear was that the Americans had gathered some intelligence about the Japanese testing biological weapons, especially at Unit 731 in Pingfan, Manchuria.
But an investigation of the attached weapons found on the balloons that had crashed to the ground dispelled this fear. If the balloons had indeed  been carrying deadly germs, there would have been a good reason for panic to spread. 
A report by Associated Press of a “huge paper balloon, bearing Japanese ideograms” that had landed near Kalispell, Montana, appeared in newspapers on December 19,1944, but the Federal Bureau of Investigation (FBI)  warned not to discuss the balloon, so “the whole town clammed up.” The FBI said the balloon carried a single bomb, but would not confirm on where it had originated.
In Washington “military experts” speculated that it was either a barrage balloon that escaped a Japanese island outpost, a balloon brought to the U.S. by Japanese saboteurs, a new Japanese “secret weapon,” or it was a balloon launched from a Japanese submarine off the U.S. Pacific Coast. 
Newsweek carried a January 1, 1945, article entitled, “Balloon Mystery,” and a newspaper reported the same story a day later.
But these were the only reports that reached the Japanese. Still, these initial  reports proved to the Japanese high command that the concept was basically sound and allowed the program to continue (Mikesh).
On January 4, 1945, the Office of Censorship requested that editors and radio broadcasters give no publicity to balloon incidents, which was also the course followed in Canada.
“The Japanese listened eagerly to radio reports, hoping to hear of the bombs’ effectiveness,” reported the Associated Press on October 2, 1945, weeks after the war ended. “But American editors voluntarily kept the information to themselves and so discouraged the Japanese that they abandoned the project.
“The Japanese learned of only one bomb landing in the United States. It was one which came down in Wyoming and failed to explode.”
Many civilians were aware of the balloons through eyewitness and word-of-mouth accounts, but they co-operated with the U.S. and Canadian governments and kept quiet about balloon landings they had witnessed.
For example, the Oxford House incident in Manitoba was not reported until December 1945, which was months after the Japanese surrender on August 15 (the documents officially ending the war were signed on September 2, 1945).
Three months after the January 1945 request not to report the balloon incidents, the American Office of Censorship wrote newspaper editors and broadcasters: “Co-operation with the press and radio ... has been excellent despite the fact that Japanese free (unmanned) balloons are reaching the United States, Canada and Mexico in increasing numbers ... There is no question that your refusal to publish or broadcast information about these balloons has baffled the Japanese, annoyed and hindered them, and has been an important contribution to security.” 
“To their silence is credited the failure of the enemy’s campaign,” reported the New York Times on May 29, 1947.
Cheap and easy-to-build, the unmanned balloons carried a modest payload — they couldn’t by any stretch of the imagination be classified as “weapons of mass destruction” — varying from a 12-kilogram (26 pound) incendiary to one 15-kilogram (33-pound) anti-personnel bomb and four five-kilogram (11-pound) incendiary devices. A series of fire bombs were placed on the periphery of the ring, while a single anti-personal bomb was attached to the centre of the ring. The incendiary bombs were primarily intended to set forest fires — an unlikely occurrence as the balloons were launched at a time when coastal forests were soaked by heavy rainfall — while the anti-personal devices were meant to terrorize the West Coast’s civilian population.
In reality, the balloon bombs failed to achieve their intended goals. Only 285 balloons were confirmed to have reached North America (80 in Canada; two even landed in Mexico) — many fell harmlessly into the Pacific Ocean and most bombs dropped in isolated areas causing little damage or the bombs failed to detonate. 
The fact that so many balloons or balloon fragments and bombs were recovered in Canada and the U.S. was an indication of the failure of all the 32 sandbags to be released in order to trigger the detonations. And since the bombs could not be armed until their were released from their carrying device, they were usually inactive, unless handled incautiously (Mikesh).
A short film entitled, Japanese Paper Balloons, a Second World War United States Navy Training Film, shows a Fu-Go in flight and then landing on the  ground with its payload intact. In the film, an officer indicates the still attached ballast and bombs (the now declassified film is available on the Internet).
A Fu-Go balloon soon proved it could be a deadly weapon.
      (Next week: part 2)