As far as engineering goes, the USS Scorpion was sunk by a failure of engineering somewhere. All of the likely scenarios imply such failure. Same with the USS Thresher.

So much for the infallibility of engineering in critical systems. It ain’t always there. To claim that complicated systems, no matter how destructive a failure would be, are immune to unforeseen and cascading engineering mistakes and material failures would be silly. I know you aren’t doing that, but I can’t tell what you are doing.

You envisioned a “single point of failure” that connected all securing devices. My analogy, bad or good, intended to show that only bad engineers design their controls that way. And an electrical engineer would be no more likely to make that mistake than a gunmaker.

And to tell the truth, I don’t know what I’m talking about. I know nothing about the safeguards or triggering mechanisms on nukes. It just SEEMS to me possible that a pretty good design could be prone to compromise by a short circuit as the result of a mechanical catastrophe

If the short circuit was in that totalizer, I can see where there could be problems. I’m sure it could be designed to make that possibility remote, and I can see where at least theoretically there could be a weak point.

As far as accidental detonations, clearly that hasn’t happened. However, we, that is folks like you and I, don’t have the slightest idea how many close calls there have been. Could be none, could be hundreds.

People looking at the “front” of the arming mechanism might have seen 4 different switches (or analogs) in 4 different places, whereas behind the panel doors there could ultimately been one circuit which totaled all the other responses. That circuit when shorted could have interpreted 3 “OK’s” and just left the 4th to be tripped. After all, something had to add up all the inputs, presumably in one place.

The “fulcrum” in this story is Parker Jones, the Sandia lab supervisor and his original 2-page commentary.

That’s a pretty fragile fulcrum.

Who is Parker Jones, how reliable is he, and did he have axes to grind? I can find almost nothing on him prior to this latest flap.

This is an issue for any major story where all the sources track back to a single “fulcrum” point, like one news story, one person, or one science paper.

Even with conventional weapons, like artillery shells, there are usually several layers of interlocking fail-safes, arranged in sequence and requiring deliberate actions by the gunners to activate the charge, each designed so that a failure in any will make the weapon inert. Crews are extensively drilled with dummies so that arming weapons becomes second nature, even should the gunner or bombadier is highly stressed. The result is that in combat, bombs and shells often refuse to explode when they’re supposed to, and only in cases of extreme stupidity or deliberate sabotage do munitions explode prematurely.

I’ve never handled nukes before, but I imagine the safeties would be even more extreme than with conventional bombs or rounds. For example, I would expect a key part of the fuse would be stored separately, and have to be manually inserted into the weapon by ground or air crews immediately before action, and only if action was imminent. In addition, the commander would have an additional arming switch that only he could activate. When the weapon was deliberately (not accidentally) released, the fuse would activate, and only then would the radar or barometric altimeter trigger be functional. Maybe things are different with nukes (security?) but it doesn’t seem to me it would be very difficult or expensive to design these safeguards in.