Grinding...

A unit trip can also be caused by things one does not expect...

The position of the shaft is monitored by so-called proximitors which detect how the shaft behaves in the bearings.
Normally the shaft rotates smoothly at 3000 revs per minute but when the alignment is not good or the bearing is defective the shaft is going to bump through the bearing and that expresses as vibrations.
Yesterday the shaft ran smoothly when it was still "cold" but today when the steamturbine was heated up the shaft shifted a bit and a small roughness on the shaft came near the proximitors and they "saw" high vibrations which caused the unit to stop automatically.

Here the cover of the bearing has been taken off and with a piece of sandpaper the shaft is smoothened..
The shaft is turning very slowly at 1 RPM by means of a hydraulic ratchet (a haulic motor)

We are trying to start up in a few hours..

Here is the bearing located in the front.