cicerone imposter wrote:
Not true: There are safety features on nuclear bombs that are error proof. That's the reason there have never been anything perilously close to a nuclear explosion. What you may have read in the media are all false. I worked with them for four years.
The very large bombs that we carried in bombers in the 1960s had four safety features.
#1 required a certain amount of electrical current to be applied to the bomb to rotate a cylinder therein. Rotated one way, all the pathways needed for the bomb to detonate were open. Rotated the other way, all the pathways were blocked and detonation was impossible. Electrical current could only be applied if both the pilot and the bomber (who were in different sections of the plane) simultaneously held down a button.
Unfortunately wiring was sometimes faulty, and there were a number of instances where bombs got enough current to arm themselves without the crew even realizing it until the plane was back on the ground.
#2 required a large pin to be pulled out of the bomb (something like pulling the pin from a grenade). This pin was connected to a rope that went to the pilot, who would pull the pin by pulling on the rope.
#3 required a heavy strip to be pulled from the bomb. One end of the heavy strip was permanently attached to the bomber, and when a bomb was dropped and fell from the plane, the strip would be pulled out by the bomb falling away from the plane.
#4 required the bomb to sense that air was rushing by it at a high velocity (consistent with freefall after being dropped from the plane).
Unfortunately there were two cases where a plane broke apart in midair and the rope in #2 snagged, pulling the pin out as the plane started to come apart, then the bomb fell from the plane as the plane broke apart further, which also pulled out the strip from #3, and then the freefalling bomb sensed the air rushing by appropriately, so #4 was also activated.
In both cases the only
thing that prevented a full-yield explosion was #1. The electrical current had not been applied to either bomb.
But given all the cases where faulty wiring did apply electrical current to bombs without anyone realizing it, we were very very lucky.
In one of the two "almost" cases, the bomb was a 4 megaton dirty bomb set for groundburst. I haven't found conclusive data on the other case, but I suspect that that bomb might have been even worse yet.