satxdiver: just be slightly correct your insight into the problem, the issue is not with the diesel generator sets on board the ship. There are 6 such sets, and the power from them can be distributed as required to propulsion motors or the hotel requirements of the vessel. The current problem is with the actual electric motor than turns the shaft. Some of the electrical windings within that motor are not working, and thus the motor can not turn as fast as when all the winding are in good order. During the refit they will either: A) cut a large hole in engine room plating, remove the defective motor and then place a new one aboard, or B) strip down the defective motor and rebuild it while it is in place within the engine room. So far, it would appear that option A is favoured.