Balloon bomb
Balloon bombs or fire balloons are unmanned, unguided balloons that carry a risk of fire or explosive charge which is automatically discarded or released after a certain time. The hit rate is correspondingly low, which is why balloon bombs never played a major role in military conflicts.
Balloon bombs were first used by Austrian troops in 1849 to suppress rebellions in Italy. In World War II , the Japanese army "wind ship bombs" set ( Jap. 風船爆弾 , FUSEn bakudan ) or "Code F-weapons" ( ふ号兵器 , Fu gō heiki ) that bombs from Japan over the Pacific to America wore. About 9,000 such balloons were launched on the east coast of the Japanese island of Honshu ; six people were killed by one of the 300 balloon bombs that actually hit the mainland.
Similar but less sophisticated balloons were used by the British from 1942 to 1944 during Operation Outward . They were of benefit to the British - in contrast to the Japanese attempts - and they successfully hindered the activities of the German Air Force .
The balloon-driving spy cameras (project name: "Moby Dick", February 1953 to June 1954) and tethered balloons for reconnaissance and anti-aircraft purposes or as an early means of transport are further applications of the principle of the American side, with more or less success used at the beginning of the Cold War military balloons.
Austrian balloon bombs
The first balloon bombs were developed in 1848–1849 by the Austrian artillery officers Franz and Josef Uchatius under the direction of Major General Franz von Hauslab . The balloons were filled with hydrogen, and a slowly burning fuse triggered the release of the explosive charge.
When Austrian troops besieged Venice in the summer of 1849 , it turned out to be impossible to force the city to surrender as there were no long-range guns to bombard the islands from the mainland. Field Marshal Radetzky therefore requested the first 14 balloon bombs on June 2, 1849.
The first attacks failed because the balloons were carried away from the city by constantly changing winds. On July 2nd, 1849, the first bomb exploded in Murano. Encouraged by this, further attacks continued to be carried out over the next eight weeks. The damage done by the balloon bombs, each loaded with 15 kg (30 pounds) of explosives, was very slight, but the psychological effect was considerable. Venice surrendered on August 2, 1849. The hit rate was so low that the KK Army refrained from using balloon bombs again.
Japanese balloon bombs
When the American General Jimmy Doolittle (then Lieutenant Colonel ) surprised Japan in the spring of 1942 with his North American B-25 "Mitchell" bombers in the so-called Doolittle Raid , he set a series of events in motion led to an attempt by Japan to attack the American mainland with bomb-carrying balloons.
In the Doolittle Raid , the medium-weight twin-engine B-25 bombers took off to attack Japanese industrial plants . The sheer boldness of the attack and the first use of bombers from an aircraft carrier startled Japan despite the long flight distance and many ditchings due to lack of fuel and forced the leadership to give a military response.
From late autumn 1944 to spring 1945, the Japanese army dropped more than 9,000 balloon bombs. The ascent took place from mainland Japan. The Americans initially assumed that the balloon bombs were launched from ships or submarines off the American coast. On the hydrogen balloon, an automatic system ensured that ballast was dropped or gas was blown off to regulate the altitude. The last “ballast” was the bomb load from several incendiary bombs or an explosive bomb, and then the hydrogen-filled balloon was ignited with an incendiary charge.
The first balloon bombs were launched two days after the start of regular US bombardments of mainland Japan on November 3, 1944. Balloon bombs were eventually found in Alaska , Washington , Oregon , California , Arizona , Idaho , Montana , Utah , Wyoming , Colorado , Texas , Kansas , Nebraska , South Dakota , North Dakota , Michigan and Iowa as well as Mexico and Canada . The last balloon was launched in April 1945. The last live balloon bomb was found in North America in 1955 with a bomb load still explosive after ten years . A bomb defused by weathering was discovered in Alaska in 1992.
Three hundred of around 9,000 weapons launched were found in the United States or observed flying over them. According to American and consistent Japanese estimates, about 1,000 balloons reached the North American target area. Despite the high expectations that were placed on them, the decentrally handcrafted paper balloons were worthless as a weapon, since apart from one incident with six dead they claimed no victims and hardly caused any damage.
The balloons were only used in autumn and winter. The intended and ultimately hardly achievable forest fires could only have been started if they had been deployed in summer. The greatest achievement was the interruption of the power supply to a reactor of the Manhattan Project . A core meltdown did not take place, the emergency power supply worked.
The balloon bombs did little damage, but had some frightening effect on the American population. The US counter-strategy was to prevent the Japanese from learning about the effectiveness of their weapon. Apart from a few censorship measures that were necessary, the press reported little of its own accord about the bombs. Hence, the Japanese believed their idea didn't work after hearing about a single, failed bomb that fell in Wyoming. In addition, two suppliers of hydrogen gas in Japan were - largely unintentionally - destroyed by American bombings. This is how the “windship bomb” project ended.
Origin and beginning
The balloon campaign wasn't the first time the Japanese had attacked mainland America. It was actually the fourth attack. In February 1942 - before the Doolittle Raid - the submarine I-17 attacked an oil field near Santa Barbara (California) and damaged its pumping station . I-25 followed in June, attacking a coastal fortification (and defacing a baseball field ) on the Oregon State coast . In September of that year, the crew of the same boat assembled a small seaplane that was carried along, which then set off several small forest fires with incendiary bombs .
The balloon bombing operation was the most serious of all these attacks on the American mainland. The idea came from the Technical Research Laboratory of the Japanese 9th Army under the direction of Major General Sueyoshi Kusaba , which worked with Major Technical Teiji Takada and his colleagues. The main consideration was to take advantage of the strong wintry winds discovered by the Japanese Air Force . Today this wind is called Jetstream .
The jet stream blows at a height of over 9,150 meters and can carry a large balloon across the Pacific in three days - over a distance of more than 8,000 kilometers. Such balloons could carry incendiary bombs and other explosives into the United States, where they could kill people, destroy buildings, or start forest fires.
The preparations for this project took a lot of time because there were major technical problems. Gas balloons expand when they are illuminated by the sun and so rise. When it gets cold at night, the balloon contracts and the aircraft sinks. The engineers of the laboratory developed a control system that at one altimeter was connected. When the balloon drove deeper than 9,000 meters, an automatic system controlled by the altimeter dropped sandbags so that the balloon rose again due to its lower weight.
Similarly, if the balloon went higher than 11,600 meters, it was steered: the altimeter opened a valve to release hydrogen from the balloon. The gas was also released at a critical overpressure ( rebound height ).
The control device guided the balloon for three days. After this time it was likely that the balloon was over the United States, and after two nights the balloon was no longer ballasted. At the end of the flight a small detonator was detonated at the top of the gas balloon, which destroyed the balloon. The actual 15 kilogram bomb was dropped, causing it to explode on the ground.
The balloon had to be able to carry a weight of around 500 kilograms, which meant that the balloon had to be ten meters in diameter and 540 m³ in volume. At first the balloons were made of conventional rubberized silk , but later a design was found that was even more gas-tight. The army command ordered ten thousand balloons made of Japanese paper - a dense and tough paper made from mulberry trees . This paper was only available in rectangles the size of a map , so it was glued in three or four layers with edible konnyaku paste. Hungry workers kept stealing and eating this paste. Many manual workers were underage girls with finer fingers than other people; They were ordered to wear gloves, keep their fingernails short and not use hairpins, probably in order not to damage the sensitive paper. The girls assembled balloons in many places in Japan and knew nothing about the purpose of these structures. When rumors got around that the balloons would fly to America and start a fire there, many of the workers found it ridiculous. Large buildings such as sumo facilities, gyms and theaters were requisitioned in order to manufacture the balloons. The balloon project was nevertheless kept quite successfully secret.
attack
The first tests of the balloons took place in September 1944 and were satisfactory. However, before the preparations were finished, American B-29 aircraft attacked the main Japanese islands. These attacks fueled Japan's desire to avenge the Doolittle Raid .
The first balloon was released in early November 1944. Major Takade observed as the balloon rose high above the sea:
- "The figure of the balloon was only visible for a few minutes after take-off, until it disappeared as a spot in the sky - like a star in the daytime."
At the beginning of 1945, Americans were shaken awake to the realization that something strange was going on. Balloons have been spotted and explosions heard - from California all the way up to Alaska. An object resembling a parachute sank to the ground over the city of Thermopolis , Wyoming. A cluster bomb detonated and shrapnel was found around the crater. A P-38 Lightning shot down a balloon near Santa Rosa, California; another was spotted over Santa Monica, also California. Pieces of Japanese paper were found on the streets of Los Angeles .
Two balloon bombs were found in a single day in the Modoc National Forest east of Mount Shasta . A bomb exploded in huge flames near Medford, Oregon; the United States Navy found balloons in the ocean. Balloon covers and devices for the balloons have been found in Montana and Arizona, as well as in the Canadian districts of Saskatchewan , Northwest Territories, and Yukon. Finally, an army pilot managed to capture a balloon and bring it to the ground intact, where the balloon was examined and photographed.
Public reaction
Newsweek magazine published an article in its January 1, 1945 issue entitled "Balloon Mystery" and a similar report appeared in a newspaper the next day. The Censor Board ( "Office of Censorship") sent a message to all the newspapers and radio stations and asked them not to mention incidents with balloons and fire balloon, so that the Japanese no news about the effectiveness got their aircraft.
From a military point of view, it was unwise to start the balloons only from autumn to spring. The bombs could have started forest fires, but at that time of the year it was too humid for the forests to catch fire. In the summer - when there is a risk of forest fire in the USA - no balloons were launched.
However, authorities were concerned about the balloons - there was a very good chance that the Japanese could cause more damage by accident. Worse still, the Americans knew that the Japanese army was working on biological weapons in the infamous " Unit 731 " in Pingfan, a city in occupied Manchuria . A balloon with highly infectious pathogens would have had serious consequences.
No one in America believed that the balloons came directly from Japan. Rather, it was assumed that the balloons were launched by Japanese special forces that landed on the US west coast in submarines. Wilder theories suggested that they were started by Germans from POW camps or even from the internment camps where all Japanese citizens living in the United States were interned .
Some of the ballast sandbags dropped by the “fusen bakudan” were examined by the US Geological Survey . In collaboration with Army Intelligence Colonel Sidman Poole , the sand was analyzed microscopically and chemically; The remains of marine microorganisms (including diatoms ) and the mineral composition were also examined. The investigations showed that the sand could not have come from an American beach or from the Pacific islands, but had to come from Japan.
Meanwhile, balloons were arriving in the states of Oregon , Kansas , Iowa , Manitoba , Alberta , Northwest Territories , Washington , Idaho , South Dakota , Nevada , Colorado , Texas, as well as northern Mexico , Michigan, and near Detroit . Fighter planes tried to intercept the balloons, but with little success, because the balloons went very high and surprisingly fast; fewer than 20 were shot down.
The geologists continued their studies of the sand and were even able to determine which Japanese beaches the sand came from. In the end, however, the results were unimportant as it was springtime and the balloon attacks would soon end.
Victims: six civilians
On May 5, 1945, five children and one woman, Elsie Mitchell, were killed by a balloon bomb near Lakeview, Oregon . The victims tried to drag such a device out of the forest when it exploded. The husband, Reverend Archie Mitchell, witnessed the accident while on an outing with some children. The five children between the ages of 11 and 13 and the woman remained the only known victims of the Japanese balloon attacks. However, one has to reckon with the fact that there are a number of balloon bombs that have not yet been found and that are still dangerous even decades later.
Japanese propaganda claimed that there was major fire and panic among the population in the United States . 10,000 dead were reported on the radio.
After the fatal incident, the press censorship was lifted so that the public could be warned of the danger of ballooning. But even without censorship, the Japanese would have had no reason to believe that they had achieved anything militarily.
Benefits and effort
General Kusaba's people sent more than 9,000 balloons on the trip, around 300 of which were found or observed in the United States. Japanese estimates assumed that around 10% of the balloons made the distance; and in fact about 1,000 balloons covered this distance. Two came back and went down in Japan without doing any harm.
The effort on the Japanese side was great, and in the meantime B-29 Superfortress bombers managed to destroy two of the three hydrogen factories in the balloon project. Without receiving any indication of the efficiency of the project, General Kusaba had to stop the balloon launches in April 1945.
On March 10, 1945, one of the last balloon bombs got caught in a power line near the Hanford nuclear facility used for the Manhattan Project - the construction of the American atomic bomb. The power went out briefly in the system until an emergency generator started.
Operation Outward in the UK
Operation Outward was the name of the British program to attack the German Empire with free-flying balloons during World War II.
During “Outward” cheap, simple gas balloons were filled with hydrogen. They carried two types of payload:
- a steel cable with the aim of hitting power lines and thus causing an electrical short circuit or
- three incendiary bombs weighing 2.7 kilograms each to set forests and dry meadows on fire
A total of 99,142 balloons were launched during Operation Outward. 53,343 carried incendiary devices, 45,599 steel cables.
Compared to the more popular Japanese balloon bombs, the Outward balloons were built much simpler. However, they only had to cover a much shorter distance, drove lower (only 4,900 instead of 11,500 meters) and also had no automatic height control. It was very easy to mass produce and only cost 35 shillings (1.75 pounds ) each .
The project was initiated by a storm that raged on the night of September 17, 1940 and tore off a number of British tethered balloons and carried them eastward across the North Sea . Some balloons reached Sweden and Denmark and damaged power lines, interrupted railway lines and destroyed the antenna of the Swedish international broadcaster. Five balloons finally even reached Finland .
A report on the damage and confusion in the affected countries reached the British cabinet . On September 23, Winston Churchill ordered that the use of balloons against Germany should be discussed.
The aviation ministry first issued a negative report, presumably because the responsible ministry for aircraft construction assumed that balloons were inefficient weapons and that making them would tie up too much energy. The Admiralty was more positive about the idea. She found that balloons were very cheap flying objects and that their use in no way endangered the lives of British people. The design of the German power grid would also be sensitive to short circuits and large forests would be suitable targets for incendiary bombs . In addition, winds above 4,900 meters would mostly blow from west to east, which would make it impossible for Germany to use balloons as a weapon itself.
After a lengthy bureaucratic battle between the Aviation Ministry and the Admiralty, the General Staff decided in September 1941 that the project should begin. The first launch site was set up in Harwich , and the first balloon flights began on March 20, 1942. Within a few days, the British received reports of forest fires near Berlin and Tilsit in East Prussia .
Reports from the German Air Force , which were intercepted by the British, quickly showed that the German fighters were trying to shoot down the balloons. This fact encouraged the British army command to continue "Operation Outward" - after all, it was a lot more expensive for the German Air Force to destroy a balloon than it was for the British to manufacture one.
Operation Outward achieved its greatest success on July 12, 1942: A balloon with an attached steel cable hit a 110,000 volt line near Leipzig . A faulty overload circuit breaker in the Böhlen power station led to a fire that destroyed the entire station.
The balloon launches continued, even if they were temporarily interrupted so as not to obstruct the Allied bombers during the major air raids. In the preparatory phase for the invasion of Normandy , the number of balloon launches decreased. The last balloon was launched on September 4, 1944.
Palestine / Israel
In early 2020, it was reported that balloon bombs were also being used in the Israeli-Palestinian conflict . These are balloons built with simple means, e.g. Partly from condoms that were filled with refrigerant as a lifting gas . Incendiary bombs or explosive devices were sent from the Gaza Strip to Israel by Hamas as a "payload" .
literature
Austrian balloon bombs
- Hans Kronberger: The Austrian balloon book. Hora-Verlag, Vienna 1987, ISBN 3-213-00016-7 .
- Monash University, Remote Piloted Aerial Vehicles: An Anthology
Japanese balloon bombs
The original English text of this article consists of "The Fire Balloons" (public domain, see below) and "Balloon Bomber" ( Memento from January 17, 2008 in the Internet Archive ), also in the public domain because it was created by a US government agency .
- The Fire Balloons by Greg Goebel, February 1, 2000, minor update June 1, 2002, accessed July 30, 2016.
- Robert C. Mikesh: Japan's World War II Balloon Bomb Attacks on North America. Smithsonian Institution Press, 1973.
- John McPhee: Balloons Of War. In: The New Yorker . January 29, 1996, pp. 52-60.
Operation Outward
- James Healy: Operation Outward. In: Aviation News Magazine. October 31 (- November 13) 1986, pp. 590-591.
- Curtis Peebles: The Moby Dick Project. Smithsonian Books, 1991, ISBN 1-56098-025-7 .
See also
- Operation Royal Marine - contact-controlled drifting mines in the Rhine 1940
Web links
- Brief description from the US Air Force Museum, Wright-Patterson AFB ( Memento from July 18, 2006 in the Internet Archive )
- Summary and sketches ( memento of February 1, 2009 in the Internet Archive ) (English)
- Basis of this article by Greg Goebel ( Memento from January 1, 2012 in the Internet Archive )
- 555th Parachute Battalion (Hanford Incident)
- Balloon Bombs ( Memento from June 9, 2008 in the Internet Archive )
Individual evidence
- ↑ Johann Werfring: K. uk balloon bombs on the city of Venice ( Memento of the original from July 19, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. In: “Wiener Zeitung”, March 18, 2010, supplement “ProgrammPunkte”, p. 7.
- ↑ Salzburger Wehrgeschichtliches Museum - SWGM ( Memento of the original from August 17, 2014 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved May 5, 2009.
- ↑ United States Department of Energy : The Handford Site Historic District. Chapter 2, section 8.2 ( Memento of February 27, 2009 in the Internet Archive )
- ^ Reply to explosive balloons Israel attacks targets in Gaza Strip. NTV.de, January 26, 2020, accessed on February 5, 2020 .
