The M33 cluster bomb, also known as the (M33) Brucella cluster bomb, was a U.S. biological cluster bomb developed in the early 1950s and deployed in 1952. It was the first standardized biological weapon in the U.S. arsenal.

History

The U.S. Army Chemical Corps selected ''

Brucella suis ''Brucella suis'' is a bacterium that causes swine brucellosis, a zoonosis that affects pigs. The disease typically causes chronic inflammatory lesions in the reproductive organs of susceptible animals or orchitis, and may even affect joints and ...

'' as its first mass-produced

biological agent Biological agents, also known as biological weapons or bioweapons, are pathogens used as weapons. In addition to these living or replicating pathogens, toxins and Toxin#Biotoxins, biotoxins are also included among the bio-agents. More than 1,2 ...

in 1949. Tests at

Dugway Proving Ground Dugway Proving Ground (DPG) is a United States Army facility established in 1942 to test biological and chemical weapons, located about southwest of Salt Lake City, Utah and south of the Utah Test and Training Range. Location Dugway Provin ...

followed in 1950 and 1951. These tests paved the way for the first mass-produced biological weapon in the U.S. arsenal in 1952.Croddy, Eric and Wirtz, James J. ''Weapons of Mass Destruction: An Encyclopedia of Worldwide Policy, Technology, and History'',
Google Books
, ABC-CLIO, 2005, p. 75, (), accessed November 13, 2008.

Specifications

The M33

cluster bomb A cluster munition is a form of air-dropped or ground-launched explosive weapon that releases or ejects smaller submunitions. Commonly, this is a cluster bomb that ejects explosive bomblets that are designed to kill personnel and destroy vehi ...

was a biological munition that initially carried the biological agent ''

''. The M33 held 108 M114 anti-personnel bombs; each M114 held about 320 milliliters of ''B. suis'' culture.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 The Borden Institute is a U.S. Army “Center of Excellence in Military Medical Research and Education”. In 1987, U.S. Army Colonel Russ Zajtchuk conceived the idea for a “Center of Excellence in Military Medical Research and Education,” u ...

'', Textbooks of Military Medicine, PDF via

Maxwell-Gunter Air Force Base Maxwell Air Force Base , officially known as Maxwell-Gunter Air Force Base, is a United States Air Force (USAF) installation under the Air Education and Training Command (AETC). The installation is located in Montgomery, Alabama, United States. ...

, accessed November 13, 2008. Besides ''B. suis'' the M33 was tested with other agents throughout the 1950s. The M33 was an air-released munition: released at high altitude, it would eject its bomblets while still aloft. Each bomblet would then explode using its own detonator.Regis, Edward. ''The Biology of Doom: The History of America's Secret Germ Warfare Project'',
Google Books
, Macmillan, 2000, p. 140-56, ().

Issues

The M33 presented a special logistical problem. The agent used, ''B. suis'', required refrigeration which created a logistical "nightmare". In addition, experts calculated that to attain a proper infection rate over an area of one square mile up to 16 separate M33s were required; around 1,500 individual bomblets. The large number of

biological weapon Biological agents, also known as biological weapons or bioweapons, are pathogens used as weapons. In addition to these living or replicating pathogens, toxins and Toxin#Biotoxins, biotoxins are also included among the bio-agents. More than 1,2 ...

s made transport of the weapons for 1952 tests more difficult. The M33 cluster bomb was never used in battle.

Tests involving the M33

The M33 cluster bomb was used in a series of tests from August-October 1952. At

, Utah, the Army Chemical Corps exposed over 11,000

guinea pig The guinea pig or domestic guinea pig (''Cavia porcellus''), also known as the cavy or domestic cavy ( ), is a species of rodent belonging to the genus ''Cavia'', family Caviidae. Animal fancy, Breeders tend to use the name "cavy" for the ani ...

s to ''B. suis'' via air-dropped M33s. Although the guinea pig trials caused one Chemical Corps general to remark, "Now we know what to do if we ever go to war against guinea pigs", the tests resulted in the realization that the M33 could not compete with the casualty volume caused by

atomic weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission or atomic bomb) or a combination of fission and fusion reactions (thermonuclear weapon), producing a nuclear expl ...

References

{{U.S. biological weapons Biological weapon delivery systems Cluster munitions Military equipment introduced in the 1950s