1879. If you are underway at full speed on a vessel fitted with a main propulsion turbine pressure lubrication system, which of the following actions will be necessary upon complete loss of lube oil pressure?

Loss of lube oil pressure at full speed requires immediate action to rapidly decelerate the turbine shaft and prevent bearing damage; closing the ahead throttle and admitting astern steam via the guardian and astern throttles provides the fastest safe method for deceleration.