Question 169General Subjects - 1st Asst/Chief

The correct answer is D) Stern tube shaft. The stern tube shaft is the section of the main propulsion shafting that passes through the hull penetration to the closest watertight bulkhead. This shaft is supported by the strut and strut bearing as it exits the hull. The stern tube provides a watertight seal around the shaft as it passes through the hull, preventing water ingress. This is a critical component in the overall shafting arrangement for a vessel with a strut-supported propeller. The other options are incorrect because they refer to different sections of the shafting system. The tail or propeller shaft is the section that connects the propeller to the stern tube shaft, the line shaft runs between the engine and the stern tube shaft, and the thrust shaft is responsible for transmitting the engine's thrust to the hull.