Question 119Motor Plants - Assistant Engineer

The correct answer is D) Admission of reversing start air. To stop the shaft from turning prior to changing the engine rotation for a vessel with moderate headway, the admission of reversing start air is used. The reversing start air is responsible for overcoming the inertia of the propeller shaft and main engine, allowing the shaft to come to a stop before the engine rotation is reversed. This is a critical step in the maneuvering process to ensure a smooth and controlled transition between forward and reverse thrust. The other options are incorrect because: A) The way of the vessel alone is not enough to stop the shaft from turning, B) Flywheel inertia contributes to the shaft's momentum but does not actively stop it, and C) Securing cylinder lubricators does not directly affect the shaft's rotation.