On Sun, 25 Nov 2007 20:19:46 -0500, Red wrote:

Roger Long wrote:
The bigger the diesel, the more of a factor this is
which is why railroad engines are seldom shut down for maintenance.

Roger, I am under the impression that railroad diesels are run at pretty
high "idle". In fact when waiting for the various commuter trains to get
out of the way around here I get the impression of a pretty fast running
engine when they are stopped. They do not sound anywhere near idle. Is
this the case just when they are dropping off and picking up and/or is
there another time when they actually idle slower?
Red


I think that railway engines are basically generator prime movers and
run at a constant RPM all the time. At least that is the way a power
plant engine runs. It always runs at approximately rated RPM
and the governor makes small adjustments up or down to maintain the
proper frequency.


Bruce-in-Bangkok
(Note:remove underscores
from address for reply)