On 17 July 1962, a caravan of scientists, military men, and dignitaries crossed the remote desert of southern Nevada to witness an historic event. Among the crowd were VIPs such as Attorney General Robert F. Kennedy and presidential adviser General Maxwell D. Taylor who had come to observe the “Little Feller I” test shot, the final phase of Operation Sunbeam. The main attraction was a secret device which was bolted to the roof of an armored personnel carrier, a contraption called the The Davy Crockett Weapon System.
The Davy Crockett shell weighed about seventy-six pounds, and it vaguely resembled a watermelon with fins. At thirty-one inches long and eleven inches in diameter, the projectile was too large to fit inside the gun, so it perched on the top while an attached rod was inserted into the barrel. The shell could be fired from a four-inch-wide recoilless rifle which could lob the bomb a little over a mile, or a larger six-inch-wide version which could heave it up to two and a half miles. The launchers were mounted to jeeps and personnel carriers, and each was operated by a three-man atomic squad. The Davy Crockett was also designed to detach from its vehicle, allowing the teams to relocate on foot and dispatch their miniature mutually-assured-destruction from a handy tripod mount.
The rudimentary atomic bomb did not include an abort feature, so Davy Crockett was committed to destruction once it was en route. Even with the help of the spotter gun and rifled barrel, both of the Davy Crockett launcher designs were somewhat sloppy in their accuracy, so the detonation was likely to be several hundred feet from the target.
Any person within a quarter-mile radius of the Davy Crockett explosion would face almost certain death. Those within the first 500 feet would be exposed to enough radiation to kill within minutes or hours, even with the protection of tank armor. People at about 1,000 feet from the blast would experience temporary fatigue and nausea which would then pass, but this misleading “walking ghost” condition leads to a painful death after a few days of apparent well-being. Those beyond a quarter-mile would have better chances of survival, though many would require extensive medical care, and perhaps never fully recover from their injuries. Those lucky enough to be more than one-third of a mile from ground zero would be spared most of the harmful effects, but the mutations in their DNA would give them an increased risk of cancer later in life.
The Davy Crockett’s timer allowed a minimum shot distance of about 1,000 feet, but such inept use of the weapon would certainly result in the deaths of the firing team. In most cases, the approaching Soviets would be at least one mile away, leaving the Atomic Battle Group personnel outside of the hazard zone. Even if the launcher’s lack of accuracy resulted in relatively few enemy casualties, the radioactivity from the hail of fission bombs would render a large swath of earth uninhabitable for about 48 hours, allowing time for American and NATO forces to mobilize.
In addition to being the smallest nuclear device ever developed by the United States, the Davy Crockett also has the distinction of being the last atomic device tested by the US in the open atmosphere. At least it didn’t lead to a nuclear bomb almost being detonated over North Carolina like in this case, where a nuclear bomb 250 times the size of Hiroshima bomb came very close to detonating and wiping out North Carolina.
You can see an actual Davy Crockett at the wonderful Don Pratt Museum in Clarksville on the base of Fort Campbell, It is only one of seven places that is can be seen in the US.
The Davy Crockett in more detail