The M69 incendiary

bomblet 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 used in

air raids on Japan During the Pacific War, Allies of World War II, Allied forces conducted air raids on Japan from 1942 to 1945, causing extensive destruction to the country's cities and killing between 241,000 and 900,000 people. During the first years of the Pa ...

and China during

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 ...

, including the

firebombing of Tokyo The was a series of air raids on Japan by the United States Army Air Forces (USAAF), primarily launched during the closing campaigns of the Pacific Theatre of World War II in 1944–1945, prior to the atomic bombings of Hiroshima and Nagasaki ...

in 1945. It was created by the Standard Oil Development Company, whose work was funded by the

Office of Scientific Research and Development The Office of Scientific Research and Development (OSRD) was an agency of the United States federal government created to coordinate scientific research for military purposes during World War II. Arrangements were made for its creation during May ...

. They were nicknamed "Tokyo calling cards". The M69 was a plain steel pipe with a hexagonal cross section in diameter and long. It weighed about . The bomblet used

napalm Napalm is an incendiary mixture of a gelling agent and a volatile petrochemical (usually gasoline or diesel fuel). The name is a portmanteau of two of the constituents of the original thickening and gelling agents: coprecipitated aluminium ...

as an incendiary filler, improving on earlier designs which used thermite or magnesium fillers that burned more intensely, but were less energy- and weight-efficient, and were easier to extinguish. In Germany they were filled with jellied oil and dropped in clusters of 36 in the non-aerodynamic M19 bomb. Over Japan they were used in

clusters may refer to: Science and technology Astronomy * Cluster (spacecraft), constellation of four European Space Agency spacecraft * Cluster II (spacecraft), a European Space Agency mission to study the magnetosphere * Asteroid cluster, a small ...

of 38 as part of the finned E-46 'aimable cluster', which opened up at about . After separation, each of the 38 M69s released a 3-foot (1 m) cotton streamer to orient its fuze downward. Upon hitting a building or the ground, the timing fuze burned for three to five seconds and then a small explosive charge (

black powder Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, charcoal (which is mostly carbon), and potassium nitrate, potassium ni ...

in the standard M-69 type deployed operationally during WW2,

white phosphorus White phosphorus, yellow phosphorus, or simply tetraphosphorus (P4) is an allotrope of phosphorus. It is a translucent waxy solid that quickly yellows in light (due to its photochemical conversion into red phosphorus), and impure white phospho ...

in a later modification, the M-69X, which did not see wide use) ignited and propelled the incendiary filling up to 100 feet (30 m) in several flaming globs, instantly starting intense fires. It was tested against typical German and Japanese residential structures at Japanese Village and German Village, constructed 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 ...

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

, in 1943. The M69 was the most successful incendiary in the tests. Against Japan, the M69 was carried in the bomb bay of the

Boeing B-29 Superfortress The Boeing B-29 Superfortress is a retired American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the Bo ...

, with a typical load containing 40

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 ...

s, a total of 1520 M69 bomblets. As they were very useful in China at

Hankou Hankou, alternately romanized as Hankow (), was one of the three towns (the other two were Wuchang and Hanyang) merged to become modern-day Wuhan city, the capital of the Hubei province, China. It stands north of the Han and Yangtze Rivers w ...

, the bombs were very effective in setting fire to Japanese civilian structures in mass

firebombing Firebombing is a bombing technique designed to damage a target, generally an urban area, through the use of fire, caused by incendiary devices, rather than from the blast effect of large bombs. In popular usage, any act in which an incendiary d ...

raids starting in February 1945 against Kobe. In the first ten days of March 1945, raids with the M69 and M47, extensive damage was done to Tokyo, to Nagoya, to Osaka, and to Kobe.World Battlefronts: Ten-Day Wonder
''Time'', 26 Mar. 1945

References

{{reflist Cluster munitions Incendiary weapons World War II aerial bombs of the United States

See also

References