Question 57 1AE01 - First Assistant Engineer

Which of the following propulsor types represents the proper terminology for electric propulsion where the drive motors are outside the ship's hull?

A Azimuthing propulsor
B Jet drive
C Cycloidal propeller
D Azipod propulsor
AI Explanation

The Correct Answer is D **Explanation for Option D (Azipod propulsor) being correct:** An Azipod (a trademarked term, but widely used to describe this technology) propulsor is a specific type of electric propulsion system used on ships. The defining characteristics are that the electric motor driving the propeller is housed in a submerged, steerable pod *outside* the ship's hull. This arrangement allows the entire unit to rotate (azimuth capability), eliminating the need for a rudder and improving maneuverability, while fulfilling the requirement that the drive motors are outside the ship's hull. **Explanation for why the other options are incorrect:** * **A) Azimuthing propulsor:** This is a general term describing any propulsor unit that can rotate 360 degrees to provide thrust in any direction. While an Azipod is an *example* of an azimuthing propulsor, the term "Azipod propulsor" specifically denotes the type where the **drive motor is located in the external pod**, fulfilling the specific requirement regarding the location of the electric motor. * **B) Jet drive:** A jet drive (or waterjet propulsor) uses an internal pump to draw water in and expel it at high velocity through a nozzle. The machinery (engine or motor) is typically inside the hull powering the internal pump, not located outside the hull. * **C) Cycloidal propeller:** A cycloidal propeller (such as a Voith Schneider Propeller) uses a series of vertically mounted blades that rotate around a vertical axis. While it provides excellent maneuverability, the main drive motor is typically mounted inside the hull, driving the complex gearbox and eccentric mechanisms internally.

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