On Wed, 20 Aug 2003 23:10:27 +0100, Mark Rand
wrote:

On Wed, 20 Aug 2003 00:59:00 -0500, David L Peterson wrote:


Problem is that the inlet end of the HP rotor and the IP rotor are at approx
1000 deg F during normal running. When the turbine is shut down the rotors are
more than hot enough to sag under their own weight. Either sagging or hogging
can occur with uneven cooling of any part of the rotor.

OK, now that makes a lot of sense, thanks for clearing that up.

Typically the barring
gear will be used for 48 hours after a shut down. If the electrical barring
gear is unavailable or trips due to a bent rotor, then the hand barring gear
will be used and the rotor will be turned by 1/4 turn every five minutes to
reduce the problems.


Mark Rand
RTFM

Cool, didn't know they had provisions for barring it over by hand
while assembled. How much does it take? (length of bar, number of
people, or is it through the reduction so it's just a lot of pulls)
The electric drive seemed to have a pretty big motor on it when I saw
it.