Oops, The Tybee Island Bomb

How does one loose a thermonuclear bomb?

Well, on February 5, 1958, the United States Air Force lost a 7,600-pound (3,400 kg) Mark 15 nuclear bomb in the waters off Tybee Island, Georgia. During a practice exercise, the B-47 bomber carrying the bomb collided in midair with an F-86 fighter plane. To protect the aircrew (and NOT those people below) from a possible detonation in the event of a crash, the bomb was jettisoned. Following several unsuccessful searches, the bomb was presumed lost somewhere in Wassaw Sound off the shores of Tybee and Wassaw islands.

The B-47 bomber was on a simulated combat mission from Homestead Air Force Base in Florida, where they should have stayed. It was carrying a single 7,600-pound 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. The damaged B-47 remained airborne.

The crew requested permission to jettison the bomb, in order to reduce weight and prevent the bomb from exploding during an emergency or crash landing. Permission was granted by the Air Force command, and the bomb was jettisoned at 7,200 feet while the bomber was traveling at about 230 mph. The crew did not see an explosion when the bomb struck the ocean. They managed to land the airplane safely at Hunter Air Force Base in Savannah, GA. The pilot, Colonel Howard Richardson, was awarded the Distinguished Flying Cross for saving the crew and his airplane after this incident.

Some sources describe the bomb as a functional nuclear weapon, but others describe it as disabled. If the bomb had a plutonium nuclear core installed, it was a fully functional weapon. tybee bomb1If the bomb had a dummy core installed, it was incapable of producing a nuclear explosion but could still produce a conventional explosion. The 12-foot long Mark 15 bomb weighs 7,600 pounds and bears the serial number 47782. It contains 400 pounds 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 before its flight aboard 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 made of lead. But 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 by 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.

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 the search had been unsuccessful. Based on a hydrologic survey, the bomb was thought by the Department of Energy to lie buried under 5 to 15 feet 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 in their boat with a Geiger counter in tow. Secondary radioactive particles four times naturally occurring levels were detected and mapped, and the site of radiation origination triangulated. Subsequent investigations found the source of the radiation was natural.

And why do I bring this up now?

An article posted on February 12th, 2015 in the obscure “World News Daily Report” website indicated that the warhead was located by amateur divers on vacation in the shallow waters of Wassaw Sound near Tybee Island off the Georgia Coast. After examining the cylinder and reading some writing on the side, Jason Sutter of London Ontario Canada realized that it was a missing Mk-15 nuclear warhead and immediately surfaced and called 911. Authorities from the US Navy arrived and over the course of a couple of days disarmed the device and transported to Mayport Naval Base. The validity of this article has yet to be verified by a credible news source.tybee bomb

According to a post dated Feb 17th on Dr. Jeffrey Lewis’s blog on arms control the article from World News Daily Report is a fake.

To date, no undue levels of unnatural radioactive contamination have been detected in the regional Upper Floridan aquifer by the Georgia Department of Natural Resources (over and above the already high levels thought to be due to monazite, a locally occurring sand that is naturally radioactive).

If the bomb had detonated: (Blast Area)

tybee blast