The pipe, (announcement over the intercom) is "Brace for Shock". They will also include what the threat is, and on what side of the ship (if they can). Port or Stbd. After the crunch, they
will should pipe, "Ship's company, unbrace". Which should then be followed by the action alarm bong bong sounding three times, "Emergency Stations, Emergency Stations (with further info/instructions as the situation requires) such as Fire/Fire/Fire, fire in (location), Zone (location), or Flood/Flood/Flood etc. Section base teams close up. (There are variations to what could be piped dependent upon the situation. At sea or in harbour. Working day or after hours. A confirmed emergency or a sensor indication of fire/flood/smoke etc. Get's complicated for you landlubbers...
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What should happen after everyone is told to unbrace, that the Damage Control Teams for each assigned Section Base should adopt action dress and proceed to their respective base. There should also be a concurrent rapid survey conducted of your immediate surrounding area to if possible to assess any indication of fire/flood/casualty prior to heading out to your assigned station. Hopefully by the 6 minute mark or better (desired) all the Section Bases are closed up (manned and ready), rapid surveys for damage have been made and any reports of damage sent up the chain, and command/HQ1 is directing the appropriate orders and actions to deal with the situation.
Of course Jim, it's like the Army in your drills to respond to say an ambush, you know what needs to be done and you do it as it becomes second nature. To close up for Action Stations etc the mark is 6 min or better. I have seen a close up for a real emergency flying stations, middle of the night in 3 1/2 minutes. A good crew, well drilled, is a beautiful thing to see.