Question 402Steam Plants - 1st Asst/Chief

The correct answer is A) Ahead throttle will close. When both the main and standby lube oil pumps fail on a geared main propulsion turbine operating at full sea speed, the loss of lube oil pressure will cause the ahead throttle to automatically close. This is a safety feature designed to protect the turbine bearings from overheating and potential damage due to the lack of lubrication. The other options are incorrect because: B) the lube oil sump will not overflow, C) the HP turbine bearings will overheat but this is not the first thing that happens, and D) the loss of lube oil pressure will not directly cause a loss of vacuum.