H-bomb nearly detonated on East Coast in 1961, author writes

A U.S. hydrogen bomb nearly detonated on the East Coast in 1961, with a single switch averting a blast that would have been 260 times as powerful as the device that flattened Hiroshima, a newly published book says.

In a recently declassified document, reported in a new book by Eric Schlosser, the supervisor of the nuclear weapons safety department at Sandia National Laboratories in Albuquerque said that one simple, vulnerable switch prevented nuclear catastrophe.

The Guardian newspaper in London published the document Saturday.

Two hydrogen bombs were accidentally dropped over Goldsboro, N.C., on Jan. 24, 1961, when a B-52 bomber broke up in flight. One of the bombs apparently acted as if it was being armed and fired: Its parachute opened and trigger mechanisms engaged.

Parker F. Jones at Sandia National Laboratories analyzed the accident in a document headed, “How I learned to mistrust the H-Bomb.”

“The MK39 Mod 2 bomb did not possess adequate safety for the airborne-alert role in the B-52,” he wrote. When the B-52 disintegrates in the air it is likely to release the bombs in “a near normal fashion,” he wrote. He said the safety mechanisms to prevent accidental arming were “not complex enough.”

The document said the bomb had four safety mechanisms, one of which is not effective in the air. When the aircraft broke up, two others were rendered ineffective.

“One simple, dynamo-technology, low-voltage switch stood between the United States and a major catastrophe!” Jones wrote, adding that it could have been “bad news — in spades” if the switch had shorted out.

Schlosser discovered the document, written in 1969, through the Freedom of Information Act.

It is featured in his new book on nuclear arms, “Command and Control,” which reports that through FOIA he discovered that at least 700 “significant” accidents and incidents involving 1,250 nuclear weapons were recorded between 1950 and 1968.