Question 636Steam Plants - Assistant Engineer

The correct answer is D. An emergency supply of oil in the gravity tank will provide time to crash stop the turbine and gears. The reasoning behind this is that the gravity tank is designed to provide a backup supply of lubricating oil in the event of a failure of the main and standby lube oil service pumps. This emergency oil supply allows the operator to safely shut down the engine and turbine before any critical bearings fail. The other options are incorrect because the turbine and reduction gear bearings will not immediately fail if the main lube oil pumps fail, and the hand pump is not intended to provide full emergency lubrication. The gravity tank is the proper emergency system to allow a controlled shutdown.