Originally Posted by FF
"You should never operate a generator continuously at greater than 70% load,"
Larger sets (hospital in a desert) are set to work at 90% load for lowest fuel bill and longest life.
On larger cruise ships a set will be taken off line at 70% so the other running units see a better more efficient operation.
I agree with this. Back when I was doing load calculations, and later when I was reviewing and approving them, the objective was to have the generator running at 80% - 90% as much of the time as possible. It could be tough to do with highly variable loads such as AC. Most vessels I was involved with had two generators and either paralleling equipment or split buss set ups.
BTW I'm feeling a bit foolish about repeating what I was told about the propulsion engine FW pump "weakening". I immediately though of RW and oil pumps, both of which are positive displacement and therefore can weaken with impeller wear. I don't see anything sinister here as a couple of posters suggested. I'm getting the information third hand through at least one not too technical person. There was evidence of water leakage under the pump. I'm sure the captain went down to investigate the slight temperature rise, found the pump seals leaking, and sent it out for rebuild. That is taking longer than expected so something was wrong. However, agree with posts above that whatever was causing the slight temperature rise will probably still be there when the rebuilt pump is installed.
The Captain is reported to be a gauge watcher and the engine was shut down immediately upon seeing the temperature start to rise and then only used again for a couple minutes of docking. The alarm never went off. It's also possible that the pump failed entirely and his careful monitoring saved an overheat event. I hope to talk to him when he becomes available and will report on that and the machinery survey.