During maneuvering operations for a direct...

During maneuvering operations for a direct...

Question 1 of 270705eccefa3bacbc34ba4d47d1a

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?

Question 1 of 27070

Q

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?

🔍 Key Concepts

• Direct-reversing, low-speed diesel engines and how they change rotation • What actually slows or stops the propeller shaft when the vessel still has headway • Difference between engine-side forces (air, lubrication, flywheel) and hydrodynamic forces on the hull and propeller

💭 Think About

• When the ship has moderate headway, what is physically resisting the propeller’s rotation as you try to stop or reverse the engine? • Which option represents a natural effect rather than an active control or adjustment by the engineer? • Which choices directly affect engine internal operation, and which affect the propeller through the ship’s motion in the water?

✅ Before You Answer

• Identify which options are engine control actions (things you do in the engine room) versus natural physical effects. • Consider how a freewheeling propeller behaves when the ship is still moving through the water but the engine is being brought to a stop. • Ask: Before you can admit reversing air, what must already have happened to the shaft, and what helps that happen when the vessel still has forward speed?