As shown in the illustrated electric propulsion control scheme for a twin screw vessel, when the two shaft speeds are within 5% of each other, the bridge may select "shaft synchro-phasing mode". What statement is true regarding the purpose of this operating mode? EL-0168

Correct Answer: Option C — The respective shaft speed and shaft position sensors are used to achieve identical shaft speeds and propeller synchronization to minimize shaft vibration.

Shaft synchro-phasing uses both speed and position feedback to align the propellers of a twin-screw vessel. By maintaining a specific angular relationship between the blades, the system minimizes hull vibration and noise caused by pressure pulses, ensuring smoother operation and reduced mechanical stress on the shafting and stern tube bearings.