The E77 balloon bomb was a U.S. anti-crop
biological munition based on the design of Japanese
Fu-Go balloon bomb. The E77 used feathers as a vector to disseminate anti-crop agents from a hydrogen-filled balloon and was first developed in 1950.
Background
In the late stages of
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
, Japan employed thousands of incendiary and antipersonnel weapons via unmanned balloon, using some 9,300 of these devices, releasing them into the high altitude
jet stream
Jet streams are fast flowing, narrow thermal wind, air currents in the Earth's Atmosphere of Earth, atmosphere.
The main jet streams are located near the altitude of the tropopause and are westerly winds, flowing west to east around the gl ...
to travel over the Pacific Ocean to the North American mainland.
[ The Japanese use of these balloon munitions inspired the E77, though no direct connection was made between the two.][Whitby, Simon M. ''Biological Warfare Against Crops'',]
Google Books
, Macmillan, 2002, pp. 157–67, ().
History
Development of the E77 balloon bomb began in 1950. The design of the E77 was based on the design for the World War II Japanese bomb and approved by the Army's Chemical Corps Technical Committee in April 1951. At time of its development the E77 represented one-sixth of all U.S. biological munitions efforts.[ The E77 was designated a "strategic weapon" and readied for deployment but was never used in warfare as subsequent developments in munitions supplanted the E77,][ especially the 750-pound E86 cluster bomb.][Wheelis, Mark, et al. ''Deadly Cultures: Biological Weapons Since 1945'',]
Google Books
, Harvard University Press, 2006, p. 218, ().
Specifications
Similar to the Japanese fire balloon on which its design is based, the E77 utilized a hydrogen
Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...
-filled balloon
A balloon is a flexible membrane bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. For special purposes, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), ...
. Suspended from the balloon envelope was a 32 inch by 24 inch balloon gondola. The E77 was an anti-crop munition, designed to disseminate anti-crop agents, such as wheat stem rust.[ The balloon bomb employed a dissemination method similar to that of the M115 anti-crop bomb, or "feather bomb".][ This dissemination method combined a culture of anti-crop agent with a light-weight vector, in this case, feathers.][Smart, Jeffery K. ]
Medical Aspects of Chemical and Biological Warfare
'': Chapter 2 - History of Chemical and Biological Warfare: An American Perspective,
PDF
: p. 51), '' Borden Institute'', Textbooks of Military Medicine, PDF via Maxwell-Gunter Air Force Base, accessed December 9, 2008.
Tests involving the E77
At least three separate sets of tests were conducted with the E77 balloon bomb. From October to December 1954 41 E77s were launched at Vernalis, California, which demonstrated that the munition met "military characteristics" to create high levels of plant infection on targeted crops. Further testing in 1958 showed that when cereal rust spores were delivered via an oil-based vector (wet spores) that they remained viable for longer periods in less than ideal environmental conditions. Subsequent investigations at Fort Detrick and the University of Minnesota
The University of Minnesota Twin Cities (historically known as University of Minnesota) is a public university, public Land-grant university, land-grant research university in the Minneapolis–Saint Paul, Twin Cities of Minneapolis and Saint ...
came to several positive conclusions about the effectiveness of oils as carriers of the rust spores.[
]
See also
* History of military ballooning
* Mitchell Recreation Area
* Union Army Balloon Corps
References
Further reading
*Mikesh, Robert C. ''Balloon Bomb Attacks on North America: Japan's World War II Assaults'', Aero Publishers, 1983, ()
* Webber, Bert. ''Silent Siege-III: Japanese Attacks on North America in World War II'', Webb Research Group, 1992, ().
{{U.S. biological weapons
Balloons (aeronautics)
Biological weapon delivery systems
Cold War weapons of the United States
American Theater of World War II
Balloon weaponry
Biological anti-agriculture weapons