Gengis,
The stuff of urban legend!! It is actually EXTREMELY unwise to physically move a spun-up IN without power on. This is because although the gyros are still spinning, there is no power to drive the platform gimbal motors to re-level/re-orient the platform. The gyros can precess without opposition and damage the gimbals by moving quite violently.
In the bay we never moved an IN until 5 mins or so after switching off.
John Farley,
I shiver at the memory; the system was called FINRAE if I remember correctly (Ferranti IN Rapid Alignment Equipment???)
Necessary to align the IN in RAF Harriers when aboard ship (on the way to the Falklands). Usually resulted in poor quality aligns that could dump at any motion detected.
regards,
KM-H