Mark 1 nuclear bomb

E850515

The Mark 1 nuclear bomb, also known as "Little Boy," was the first nuclear weapon used in warfare, dropped by the United States on Hiroshima, Japan, in 1945.

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Statements (49)

Predicate Object
instanceOf fission bomb
gun-type nuclear weapon
nuclear weapon
approximateYieldTNT 13–18 kilotons
15 kilotons
carriedBy B-29 Superfortress NERFINISHED
category Nuclear bombs of the United States
World War II weapons of the United States
cityCasualtiesEstimate tens of thousands killed immediately
countryOfOrigin United States of America
surface form: United States
dateOfUse 1945-08-06
deliveryMethod aerial bomb
designedAs gun-type assembly
designReliability considered highly reliable due to gun-type design
detonationAltitude about 1,900 feet
about 600 meters
detonationType air burst
developedBy Manhattan Project NERFINISHED
United States Army NERFINISHED
diameter about 28 inches
about 71 centimeters
droppedBy United States Army Air Forces NERFINISHED
droppedByAircraft Enola Gay NERFINISHED
era Cold War precursor
firstOfType first nuclear weapon used in warfare
fissileCoreType uranium projectile and target
followedBy Fat Man design family
Mark 3 nuclear bomb
hasAlias Little Boy NERFINISHED
historicalSignificance first atomic bomb used in combat
initiated nuclear warfare era
length about 10 feet
about 3 meters
mass about 4,400 kilograms
about 9,700 pounds
museumExhibit replicas displayed in various museums
operator United States Army Air Forces NERFINISHED
precededBy Manhattan Project test devices
program Manhattan Project NERFINISHED
safetyTesting no full-scale nuclear test before combat use
targetCity Hiroshima NERFINISHED
targetType urban area
usedAgainst Hiroshima NERFINISHED
usedAgainstCountry Japan NERFINISHED
usedBy United States NERFINISHED
usedInConflict World War II
usesFissileMaterial uranium-235
warheadType pure fission
yearOfUse 1945

Referenced by (1)

Full triples — surface form annotated when it differs from this entity's canonical label.

Nuclear bombs of the United States hasPart Mark 1 nuclear bomb