During maneuvering operations for a direct reversing large, low-speed, main propulsion diesel engine, which of the following actions is used to stop the shaft from turning prior to changing the engine rotation for a vessel with moderate headway?

Correct Answer: Option D — Admission of reversing start air

Admitting compressed air configured for reverse rotation creates opposing pneumatic torque in the power cylinders against the vessel's forward headway, rapidly braking the propeller shaft so the engine can successfully start and run astern.