Hydrogen Bomb Lost & Never Recovered! ~ February 5, 1958

1958 – A hydrogen bomb known as the Tybee Bomb is lost by the US Air Force off the coast of Savannah, Georgia, never to be recovered.

The 1958 Tybee Island B-47 crash was an incident on February 5, 1958 in which the United States Air Force lost a 7,600 pound (3,500 kg) Mark 15 hydrogen bomb in the waters off Tybee Island near Savannah, Georgia, USA. The bomb was jettisoned to save the aircrew during a practice exercise after the B-47 bomber carrying it collided in midair with an F-86 fighter plane. Following several unsuccessful searches, it was presumed lost somewhere in Wassaw Sound off the shores of Tybee Island.

The B-47 bomber was on a simulated combat mission from Homestead Air Force Base in Florida. It was carrying a single 7,600-pound (3,400 kg) bomb. At about 2:00 AM, the B-47 collided with an F-86. The F-86 crashed after the pilot ejected from the plane, but the B-47, despite being damaged, remained barely airworthy. The crew requested permission to jettison the bomb in order to reduce weight and prevent the bomb exploding during an emergency landing. Permission was granted and the bomb was jettisoned at 7,200 feet (2,200 m) while traveling about 200 knots (370 km/h). The crew did not see an explosion when the bomb impacted the sea. They managed to land the B-47 safely at Hunter Army Air Field. The pilot, Colonel Howard Richardson, was awarded the Distinguished Flying Cross after this incident for his role in piloting the B-47.

Recovery efforts
Starting on February 6, 1958, the Air Force 2700th Explosive Ordnance Disposal Squadron and 100 Navy personnel equipped with hand held sonar and galvanic drag and cable sweeps mounted a search. On April 16, 1958 the military announced that the search efforts had been unsuccessful. Based upon a hydrologic survey, the bomb was thought to lie buried under 5 to 15 feet (2 to 5 m) of silt at the bottom of Wassaw Sound.

In 2004, retired Air Force Colonel Derek Duke incorrectly claimed to have found the possible resting spot of the bomb. He and his partner located the spot by trawling the area in their boat with a Geiger counter in tow. The Air Force released its report in June 2005, which stated that high radiation measurements are from naturally occurring radioactive materials, and that the location of the bomb is still unknown.

Bomb
The 12-foot (4 m) long Mark 15 bomb weighs 7,600 pounds (3,400 kg) and bears the serial number "No. 47782". It contains 400 pounds (180 kg) of conventional high explosives and highly enriched uranium. The Air Force maintains that the bomb's nuclear capsule, used to initiate the nuclear reaction, was removed prior to its flight aboard the B-47. As noted in the Atomic Energy Commission "Form AL-569 Temporary Custodian Receipt (for maneuvers)" signed by the aircraft commander, the bomb contained a simulated 150 cap (which was made of lead).However according to 1966 Congressional testimony by then Assistant Secretary of Defense W.J. Howard, the Tybee Island bomb was a "complete weapon, a bomb with a nuclear capsule," and one of two weapons lost up to that time that contained a plutonium trigger.

Potential threat
In 2001, the United States Air Force conducted a study to determine whether the bomb posed a threat to residents of the surrounding area. The study concluded that the bomb does not pose a significant threat of exploding because it is missing the nuclear capsule. The bomber pilot stated that the weapon did not have the nuclear capsule when he took off. The Air Force says with certainty that the bomb contains conventional explosives and highly enriched uranium, which could pose an environmental or proliferation threat. The Air Force determined that it was prudent to leave the bomb covered in mud at the bottom of the sea floor rather than disturb it and risk the potential of detonation or contamination.

Image & text:wikipedia.com