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Japanese Fugo or Fire Balloons of WW II 23

Japanese Fugo or Fire

Balloons of WW II

From late 1944 until early 1945, the Japanese
launched over 9,300 fire balloons, of which 300
were found or observed in the U.S. Despite the
high hopes of their designers, the balloons were
ineffective as weapons: causing only six deaths
(from one single incident) and a small amount of
damage.
Rubberized silk balloon used for
meteorological observation during World War II
"Type B" rubberized silk balloon, recovered at
sea and reinflated. Outline of a human is
provided for scale.
The Japanese designed two types of
balloons. The first was called the "Type B
Balloon" and was designed by the Japanese
Navy. It was 9 m (30 ft) in diameter and
consisted of rubberized silk. The type B balloons
were sent first and mainly used for The preparations were lengthy because casing and fin assembly containing 11
meteorological purposes. The Japanese used the technological problems were acute. A ounces (310 g) of gunpowder and three 1.5-
them to determine the possibility of the bomb- hydrogen balloon expands when warmed by the kilogram (3.3 lb) magnesium containers of
carrying balloons reaching North America.[6] sunlight, and rises; then it contracts when cooled thermite.
The second type was the bomb-carrying balloon. at night, and falls. The engineers devised a • 5-kilogram (11 lb) thermite incendiary bomb
Japanese bomb-carrying balloons were 10 m (33 control system driven by an altimeter to discard consisting of a 3.75-inch (9.5 cm) steel tube
ft) in diameter and, when fully inflated, held ballast. When the balloon descended below 9 km 15.75 inches (40.0 cm) long containing
about 540 m3 (19,000 cu ft) of hydrogen. Their (30,000 ft), it electrically fired a charge to cut thermite with an ignition charge of
launch sites were located on the east coast of the loose sandbags. The sandbags were carried on a magnesium, potassium nitrate and barium
main Japanese island of Honshū. cast-aluminium four-spoked wheel and peroxide.
Japan released the first of these bomb- discarded two at a time to keep the wheel The Japanese Imperial Army Noborito
bearing balloons on November 3, 1944. They balanced. Institute cultivated anthrax and pasteurella
were found in Alaska, Arizona, California, Similarly, when the balloon rose above pestis, furthermore, it produced 20 tons of
Colorado, Idaho, Iowa, Kansas, Michigan,[7] about 11.6 km (38,000 ft), the altimeter cowpox viruses which is quantity to be
Montana, Nebraska, Nevada,[8]North Dakota, activated a valve to vent hydrogen. The equivalent to the whole area of the United
Oregon, South Dakota, Texas, Utah, Washington hydrogen was also vented if the balloon's States.[clarification needed] The plan of
and Wyoming, as well as Mexico and Canada. pressure reached a critical level. deployment of these biological weapon on fire
General Kusaba's men launched over The control system ran the balloon balloons was planned in 1944. The Emperor
9,000 balloons throughout the course of the through three days of flight. At that time, it was Hirohito did not admit deployment of biological
project. The Japanese expected 10% (around likely over the U.S., and its ballast was weapons on the occasion of a report of President
900) of them to reach America, which is also expended. The final flash of gunpowder released Staff Officer Umezu on October 25, 1944.
what is currently believed by researchers.[9] the bombs, also carried on the wheel, and lit a Consequently, the biological warfare was not
About 300 balloon bombs were found or 19.5 meters (64 feet) long fuse that hung from realized.
observed in America. It is likely that more the balloon's equator. After 84 minutes, the fuse Similar, but cruder, balloons were also
balloon bombs landed in unpopulated areas of fired a flash bomb that destroyed the balloon. used by Britain to attack Germany between 1942
North America. The balloon had to carry about 454 and 1944.
The last one was launched in April 1945. kilograms (1,001 lb) of gear. At first the balloons
were made of conventional rubberized silk, but Offensive
Origins improved envelopes had less leakage. An order
went out for ten thousand balloons made of A balloon launch organization of three battalions
The balloon campaign was the fourth attack the "washi", a paper derived from mulberry bushes was formed. The first battalion included
Japanese had made on the American mainland. that was impermeable and very tough. It was headquarters and three squadrons totaling 1,500
The fūsen bakudan campaign was, however, the only available in squares about the size of a road men in Ibaraki Prefecture with nine launch
most earnest of the attacks. The concept was the map, so it was glued together in three or four stations at Ōtsu. The second battalion of 700
brainchild of the Imperial Japanese Army's laminations using edible konnyaku (devil's men in three squadrons operated six launch
Ninth Army's Number Nine Research tongue) paste – though hungry workers stealing stations at Ichinomiya, Chiba; and the third
Laboratory, under Major General Sueyoshi the paste for food created some issues. Many battalion of 600 men in two squadrons operated
Kusaba, with work performed by Technical workers were nimble-fingered teenaged school six launch stations at Nakoso in Fukushima
Major Teiji Takada and his colleagues. The girls. They assembled the paper in many parts of Prefecture. The Ōtsu site included hydrogen gas
balloons were intended to make use of a strong Japan. Large indoor spaces, such as sumo halls, generating facilities; but the 2nd and 3rd
current of winter air that the Japanese had sound stages, and theatres, were required for the battalion launch sites used hydrogen
discovered flowing at high altitude and speed envelope assembly. manufactured elsewhere. The best time to
over their country, which later became known as The bombs most commonly carried by launch was just after the passing of a high-
the jet stream. the balloons were: pressure front, and wind conditions were most
The jet stream reported by Wasaburo • Type 92 15-kilogram (33 lb) high-explosive suitable for several hours prior to the onshore
Oishi blew at altitudes above 9.15 km (30,000 bomb consisting of 9.5 pounds (4.3 kg) breezes at sunrise. Suitable launch conditions
ft) and could carry a large balloon across the picric acid or TNT surrounded by 26 steel were expected on only about fifty days through
Pacific in three days, over a distance of more rings within a steel casing 4 inches (10 cm) the winter period of maximum jet stream
than 8,000 kilometers (5,000 mi). Such balloons in diameter and 14.5 inches (37 cm) long velocity, and the combined launch capacity of all
could carry incendiary and high-explosive and welded to a 11-inch (28 cm) tail fin three battalions was about 200 balloons per day.
bombs to the United States and drop them there assembly.
to kill people, destroy buildings, and start forest • Type 97 12-kilogram (26 lb) thermite (Continued on Page 24)
fires. incendiary bomb using the Type 92 bomb