Tybee Bomb
Encyclopedia
The Tybee Island B-47 crash was an incident on February 5, 1958, in which the United States Air Force
lost a 7600 pounds (3,447.3 kg) Mark 15
hydrogen bomb in the waters off Tybee Island
near Savannah, Georgia
, USA
. During a practice exercise the B-47 bomber carrying it collided in midair with an F-86
fighter plane. To prevent a detonation in the event of a crash and to save the aircrew, the bomb was jettisoned. Following several unsuccessful searches, the bomb was presumed lost somewhere in Wassaw Sound
off the shores of Tybee Island.
. It was carrying a single 7600 pounds (3,447.3 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 airborne, albeit barely. 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 7200 feet (2,194.6 m) while the bomber was traveling about 200 knots (392 km/h). The crew did not see an explosion when the bomb struck 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.
. 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 pound 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. Nevertheless, a study of the Strategic Air Command documents indicates that in February 1958, Alert Force test flights (with the older Mark 15 payloads) were not authorized to fly with nuclear capsules on board. Such approval was pending deployment of safer "sealed-pit nuclear capsule" weapons that did not begin deployment until June 1958.
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 by the Department of Energy 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 claimed to have narrowed the possible resting spot of the bomb to a small area approximately the size of a football field. He and his partner located the area by trawling the area in their boat with a Geiger counter
in tow. Secondary radioactive particles 4 times the naturally occurring levels were detected and mapped, and the site of radiation origination triangulated.
To date, no undue levels of unnatural radioactive contamination (over and above the already high levels thought to be due to monazite
, a locally occurring sand which is naturally high in radiation) have been detected in the regional Upper Floridian aquifer by the Georgia Department of Natural Resources
.
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
lost a 7600 pounds (3,447.3 kg) Mark 15
Mark 15 nuclear bomb
The Mark 15 nuclear bomb, or Mk-15, was a 1950s American thermonuclear bomb, the first relatively lightweight thermonuclear bomb created by the United States....
hydrogen bomb in the waters off Tybee Island
Tybee Island, Georgia
Tybee Island is an island and city in Chatham County, Georgia near the city of Savannah in the southeastern United States. It is the easternmost point in the state of Georgia. As of the 2010 census, the city population was 2,990. Tybee Island is an island and city in Chatham County, Georgia near...
near Savannah, Georgia
Savannah, Georgia
Savannah is the largest city and the county seat of Chatham County, in the U.S. state of Georgia. Established in 1733, the city of Savannah was the colonial capital of the Province of Georgia and later the first state capital of Georgia. Today Savannah is an industrial center and an important...
, USA
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. During a practice exercise the B-47 bomber carrying it collided in midair with an F-86
F-86 Sabre
The North American F-86 Sabre was a transonic jet fighter aircraft. Produced by North American Aviation, the Sabre is best known as America's first swept wing fighter which could counter the similarly-winged Soviet MiG-15 in high speed dogfights over the skies of the Korean War...
fighter plane. To prevent a detonation in the event of a crash and to save the aircrew, the bomb was jettisoned. Following several unsuccessful searches, the bomb was presumed lost somewhere in Wassaw Sound
Wassaw Sound
Wassaw Sound is a bay of the Atlantic Ocean on the coast of Georgia, United States near Savannah where which the Wilmington River flows.-American Civil War naval battle:...
off the shores of Tybee Island.
Accident
The B-47 bomber was on a simulated combat mission from Homestead Air Force Base in FloridaFlorida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
. It was carrying a single 7600 pounds (3,447.3 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 airborne, albeit barely. The crew requested permission to jettison the bomb in order to reduce weight and prevent the bomb exploding during an emergency landing
Emergency landing
An emergency landing is a landing made by an aircraft in response to a crisis which either interferes with the operation of the aircraft or involves sudden medical emergencies necessitating diversion to the nearest airport.-Types of emergency landings:...
. Permission was granted and the bomb was jettisoned at 7200 feet (2,194.6 m) while the bomber was traveling about 200 knots (392 km/h). The crew did not see an explosion when the bomb struck the sea. They managed to land the B-47 safely at Hunter Army Air Field
Hunter Army Airfield
Hunter Army Airfield , located in Savannah, Georgia, United States, is a military airfield and subordinate installation to Fort Stewart.Hunter features a runway that is 11,375 feet long and an aircraft parking area that is more than 350 acres...
. The pilot, Colonel Howard Richardson, was awarded the Distinguished Flying Cross
Distinguished Flying Cross (United States)
The Distinguished Flying Cross is a medal awarded to any officer or enlisted member of the United States armed forces who distinguishes himself or herself in support of operations by "heroism or extraordinary achievement while participating in an aerial flight, subsequent to November 11, 1918." The...
after this incident for his role in piloting the B-47.
Bomb
The 12-foot (4 m) long Mark 15 bomb weighs 7600 pounds (3,447.3 kg) and bears the serial number 47782. It contains 400 pounds (181.4 kg) of conventional high explosives and highly enriched uraniumUranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
. 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
United States Atomic Energy Commission
The United States Atomic Energy Commission was an agency of the United States government established after World War II by Congress to foster and control the peace time development of atomic science and technology. President Harry S...
"Form AL-569 Temporary Custodian Receipt (for maneuvers)" signed by the aircraft commander, the bomb contained a simulated 150 pound cap which was made of lead. However, according to 1966 Congressional
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....
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. Nevertheless, a study of the Strategic Air Command documents indicates that in February 1958, Alert Force test flights (with the older Mark 15 payloads) were not authorized to fly with nuclear capsules on board. Such approval was pending deployment of safer "sealed-pit nuclear capsule" weapons that did not begin deployment until June 1958.
Recovery efforts
Starting on February 6, 1958, the Air Force 2700th Explosive Ordnance Disposal Squadron and 100 Navy personnel equipped with hand held sonarSonar
Sonar is a technique that uses sound propagation to navigate, communicate with or detect other vessels...
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
Hydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...
survey, the bomb was thought by the Department of Energy to lie buried under 5 to 15 feet (2 to 5 m) of silt at the bottom of Wassaw Sound
Wassaw Sound
Wassaw Sound is a bay of the Atlantic Ocean on the coast of Georgia, United States near Savannah where which the Wilmington River flows.-American Civil War naval battle:...
.
In 2004, retired Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...
Colonel Derek Duke claimed to have narrowed the possible resting spot of the bomb to a small area approximately the size of a football field. He and his partner located the area by trawling the area in their boat with a Geiger counter
Geiger counter
A Geiger counter, also called a Geiger–Müller counter, is a type of particle detector that measures ionizing radiation. They detect the emission of nuclear radiation: alpha particles, beta particles or gamma rays. A Geiger counter detects radiation by ionization produced in a low-pressure gas in a...
in tow. Secondary radioactive particles 4 times the naturally occurring levels were detected and mapped, and the site of radiation origination triangulated.
Ongoing concerns
The risk of corrosion of the alloy casing of the bomb is less if it is completely covered in sand. But if, due to the shifting strata in which it is buried, part of the alloy casing of the bomb is exposed to seawater, rapid corrosion could occur, as demonstrated in simulation experiments. Eventually, the highly enriched uranium could be leached out of the device and enter the aquifer that surrounds the continental shelf in this area. Storms, hurricanes, and strong currents frequently change the sands of the continental shelf near Tybee Island.To date, no undue levels of unnatural radioactive contamination (over and above the already high levels thought to be due to monazite
Monazite
Monazite is a reddish-brown phosphate mineral containing rare earth metals. It occurs usually in small isolated crystals. There are actually at least four different kinds of monazite, depending on relative elemental composition of the mineral:...
, a locally occurring sand which is naturally high in radiation) have been detected in the regional Upper Floridian aquifer by the Georgia Department of Natural Resources
Georgia Department of Natural Resources
The Georgia Department of Natural Resources is an administrative agency of the U.S. state of Georgia. The agency has statewide responsibilities for managing and conserving Georgia’s natural, cultural, and historical resources, and is divided into six divisions:...
.
See also
- Broken Arrow
- List of military nuclear accidents
- List of nuclear accidents
- 1950 British Columbia B-36 crash
External links
- Tybeebomb.com, Informational site about the Tybee Bomb
- America's Lost H Bomb, Marabella Productions & Discovery's Science Channel documentary about the Tybee Bomb (2007)
- NPR, For 50 Years, Nuclear Bomb Lost in Watery Grave (3 Feb 2008)
- BBC News, Missing for 50 years - US nuclear bomb (22 June 2009)
- The Nuclear Information Project, Nuclear Bomb Dropped in Georgia; No Nuclear Capsule Inserted, Documents Show (2004)
- Strategic-Air-Command.com, Chart of nuclear bombs, including the Mark 15
- Chasing Loose Nukes by Col. Derek Duke (as told to Fred Dungan)