The book Debugging: The 9 Indispensable Rules for Finding Even the Most Elusive Software and Hardware Problems by David J. Agans, which was first published in 2002, contains the following claim:

On nuclear-powered subs, there's a brass bar in front of the control panel for the power plant. When status alarms begin to go off, the engineers are trained to grab the brass bar with both hands and hold on until they've looked at all the dials and indicators, and understand exactly what's going on in the system. What this does is help them overcome the temptation to start "fixing" things, throwing switches and opening values. These quick fixes confuse the automatic recovery systems, bury the original fault beneath an onslaught of new conditions, and may cause a real, major disaster. It's more effective to remember to do something ("Grab the bar!") then to remember not to do something ("Don't touch that dial!").

I have so far been unable to find any references to a bar, brass or otherwise, that nuclear sub engineers were instructed to grab when alarms go off, besides the book itself.

Were nuclear sub engineers ever actually told that when alarms go off they should grab a bar, or other inert object, until they have examined their instrument panel?

  • 5
    It is possible that the point of this bar (if it is a thing) was for the engineers to be braced in the event there is sudden movement of the ship rather than an effort to keep their hands from doing anything wrong. The bar may exist but the reason for it might be mistaken or misinformation.
    – Eric Nolan
    Dec 14, 2022 at 10:32
  • 4
    Or indeed, the bar may have been installed so the engineers could hold onto it during manoeuvring, then separately, engineers were trained to assess thoroughly before acting. Then after that at least one trainer told at least one engineer to grab the bar as a way to help them do that. Which would probably make the claim (marginally) true, but might be hard to find evidence for or against.
    – Jack B
    Dec 14, 2022 at 12:26
  • 2
    This picture of HMS Superb's manoeuvring room, from which the reactor is controlled, does show a grab bar below the instruments. So at least some western nuclear submarines had this... but whether it was used as described is another question.
    – Jack B
    Dec 14, 2022 at 12:30
  • This might be relevant to History.SE.
    – Schwern
    Dec 15, 2022 at 18:26


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