Mark 39 hydrogen bomb almost went off in North Carolina

I didn't have to jump in with both feet, either. Call it a tie?

 

Indirectly the near-disaster at North Carolina is of interest for boating, and other activities that involve safety-related technology. How could three independent safety circuits fail at once? The probability for that should be very close to zero. My guess is that the safety circuits weren't truly independent but relied on one single point of failure that had been overlooked.



Erik

 

The prudent action is....keep it SIMPLE. For boats, or whatever else. Complication is just an invitation for Murphy to get to work.

The Hiroshima Bomb was of a uranium "gun" type and was armed in flight. The Nagasaki Bomb was plutonium implosion and was armed before loading into the plane. Later designs had all sorts of "safeties" built in, even having cadmium (?) chain placed in the pit to be pulled out when arming. Makes one wonder how well they would have functioned if they had to be used for their intended purpose. Oh well, perhaps we'll get to see it yet...

 

Guys, pretty much everything you need to know is on the web about how the W-39 was weaponized and fused. At this time, there wasn't a Permissive Action Link standard, each of the several labs that were designing weapons used there own system of safeties. But basically, they often acted in series. So the weapon may have decided it had been in storage for a while, then been attached to a recognizable delivery vehicle for a while, then been detached at an acceptable altitude, then freefell for a time, and all in all this fit the programmed profile. So the weapon was enabled with respect to profile. What it lacked was a command authorization.

Having said that, I don't know if this was a battery powered or RTG powered unit. The reports suggest that the aircraft's demise somehow compromised the actual weapon's circuitry. I also don't know if both were laydown weapons. They may have had a sort of self destruct system to prevent capture of the weapons. That meant the explosives, and possibly the cores, were supposed to burn. It took a couple much worse accidents to get a standard PAL system mandated, and the military hated the idea and are generally believed to have actively worked to defeat the early systems. Reading between the lines, It sounds like the weapons had many features of the first PAL standard. It may sound funny that most weapons of this era had a combination lock on them, but that was something everybody knew how to work. The locks were electromechanical, so different combos could be used to do different things. For many years, these weapons were effectively in the hands of those with physical possession of them, and prying control away from them wasn't easy.

We have had a bit of an attitude adjustment in the interim. But it helps to understand that nobody involved at the time believed these weapons were not going to be used, it was only a question of when. The future value was steeply discounted because the odds of a relevant future were considered fairly small. Living with the bomb is something we've had to learn to do, and it didn't come easily. I say this in the hope of suggesting one possible reason for the weapon to have been found in the armed position.

I am a former engineer for Minuteman at Minot. I worked with the silos and capsules, not the warheads or missiles. I never had any particular training with respect to nuclear warheads and was never involved with aircraft systems.