The United States did not have a good year in 1958, especially when it came to transporting nuclear weapons. There was the incident where a nuclear bomb was dropped on a little girl's playhouse. There was the plane carrying a nuclear warhead that caught fire and burned for seven hours, in Morocco.
And then there's one that still haunts the coast of the Southeastern United States five decades later — the loss of a four ton thermonuclear bomb off the shore of Savannah, Georgia.
Playing war games with a nuclear bomb
A mid-air collision between a United States F-86 fighter and a B-47 bomber carrying a Mark 15 Mod 0 nuclear bomb during a simulated combat scenario left the fighter destroyed and the bomber with a damaged fuel tank and engine. And yes, flying a simulation with a detonation-ready nuclear bomb is bizarre, but it provides the most accurate preparation for a combat scenario.
After attempting to land the broken bomber (one to three times, depending on the source), the pilot of the B-47 obtained permission to jettison the nuclear bomb off the coast of Georgia.
Regardless of how asinine this plan sounds, it is the preferable of the two options — forcing a crash landing in a populated area would kill the crew and contaminate the area, creating an international incident in the process. The incident is the definition of a Broken Arrow scenario — a situation where a nuclear weapon is released, but without intent to harm.
The search is on
The bomb landed somewhere near in Wassaw Sound, near the mouth of the Savannah River and a very popular tourist destination, Tybee Island, known for its beautiful and secluded beaches available to locals. The bomb plunged into 15 to 20 feet of water, before sinking another five feet into a tomb of sand and silt.
The U.S. military searched for the unexploded nuclear bomb for nine weeks without success, using divers and ships to probe the area around Tybee Island... very, very gently. The bomb still lies somewhere off the coast 55 years later, with a 2001 recovery effort carrried out by the United States Air Force unsuccessful.
The official statement from the United States government is that the bomber jettisoned an "incomplete" nuclear bomb - one containing a chemical explosive and enriched uranium , but lacking the plutonium core necessary to initiate a fission explosion. But an official Congressional document from 1966 contradicts the idea of an incomplete bomb, stating that the crew jettisoned a complete bomb. A completed MK-15 is capable of a 1.7-3.8 Megaton explosion if detonated properly, creating a 20-30 kilometer thermal blast radius.
So where is the nuke now?
The current location of the MK-15 nuclear bomb is unknown, thanks to the passage of time and the twenty-three hurricanes and tropical storms that have hit the area since 1958.
Air Force retiree and Savannah local Derek Duke narrowed down the position of the bomb to an area the size of a football field in 2004, after spending his free time measuring ambient radiation while boating around the area, but he now believes his data is inconclusive. As of 2001, the United States Air Force believes the bomb is safe where it lies and poses little to no threat to local citizens or the ecosystem.
The condition of the bomb is an enigma — the outer metal alloy shell should be fine if it is resting in a coffin of silt. But if the bomb has been disturbed and came in contact with salt water, the metal would quickly erode, allowing the contents to seep out and distributing uranium into the water. Disturbing the bomb, if found, could also pose a danger to the recovery team if it is actually a complete nuclear bomb, containing the plutonium detonator.
Even if the abandoned MK-15 really is incomplete, some enriched uranium surrounded by four hundred pounds of TNT is essentially a dirty bomb — a dirty bomb resting just off the shore of a vibrant United States port. Recovering the bomb and the enriched uranium inside would be a coup for any nation looking to skip a few steps to becoming a nuclear power.
The top image is by T3rmin8tor on DeviantArt.
F-86 image courtesy of the USAF archives, with other images courtesy of the the United States Government, Tybee Bomb, and Google Maps. Sources linked within the article.