The 280 mm Gun at the Nevada Proving Ground Video

The testing of the Mark 9 atomic artillery shell was the Grable event, part of a much larger series of nuclear detonations under the umbrella of Operation UPSHOT-KNOTHOLE in 1953.

This operation conducted at the Nevada Test Site consisted of 11 atmospheric tests. There were three airdrops, seven tower tests, and one airburst. Conducted between March 17 and June 4, 1953, this operation involved the testing of new theories. A new and revolutionary method of producing deliverable nuclear weapons was successfully tested. Approximately 21,000 Department of Defense military and civilian personnel participated in Operation UPSHOT-KNOTHOLE as part of the DESERT ROCK V exercise.

Unfortunately, Operation UPSHOT-KNOTHOLE, particularly the "Harry" test, drew a great deal of criticism as resultant fallout levels produced increased offsite radiation exposures.

The tests comprising the 1953 Operation UPSHOT-KNOTHOLE were as follows:

ANNIE, March 17, tower, weapons related, 16 kilotons (kt)
NANCY, March 24, tower, weapons related, 24 kt
RUTH, March 31, tower, weapons related, 200 tons
DIXIE, April 6, airdrop, weapons related, 11 kt
RAY, April 11, tower, weapons related, 200 tons
BADGER, April 18, tower, weapons related, 23 kt
SIMON, April 25, tower, weapons related, 43 kt
ENCORE, May 8, airdrop, weapons effects, 27 kt [an important test in correlating blastwave and devastating precursor wave formation data of the Grable event]
HARRY, May 19, tower, weapons related, 32 kt
GRABLE, May 25, fired from 280 mm gun, 500 feet airburst, weapons related, 15 kt [equivalent to the yield of the bomb the destroyed Hiroshima, Japan]
CLIMAX, June 4, airdrop, weapons related, 61 kt

The Mark 9 nuclear artillery shell weighed 550 pounds and was fired 7 miles from the cannon firing location to the target array downrange.

The original state of this film was VERY grainy. The grain has been reduced only enough not to destroy details in artifacts resembling watercolor washing away of visual details. This film was locked away for decades in secret vaults. It therefore deteriorated over time with negelect and lack of controlled environments for what was later to be discovered as very unstable 16 mm Kodachrome I film. Colors faded, others bled through the celluloid, creating greenish to deeply blue patches in clear sky scenes, for example.

The clipping distortion of the cannon firing was in the original film and could be expected for microphones recording blasts from an 11 inches/280 mm bore cannon of 1953.