Azipod

Azipod is an electric podded azimuth thruster produced by ABB Group. Developed in Finland jointly by the shipbuilding company Masa-Yards and ABB, Azipod is a marine propulsion unit consisting of a fixed pitch propeller mounted on a steerable gondola ("pod") which also contains the electric motor driving the propeller.

Although "Azipod" is a registered brand name, it is sometimes used as a generic trademark for podded propulsion units manufactured by other companies, such as Queen Mary 2's Rolls-Royce Mermaid pods.

In the traditional azimuth thrusters such as Z-drive and L-drive thrusters, the propeller is driven by an electric motor or a diesel engine inside the ship's hull. The propeller is coupled to the prime mover with shafts and bevel gears that allow rotating the propeller about a vertical axis. This type of propulsion system has a long tradition throughout the 1900s and today such propulsion units are produced by a number of companies around the world.

In the Azipod unit, the electric motor is mounted inside the propulsion unit and the propeller is connected directly to the motor shaft. Electric power for the propulsion motor is conducted through slip rings that let the Azipod unit rotate 360 degrees about the vertical axis. Because Azipod units utilize fixed-pitch propellers, power is always fed through a variable-frequency drive or cycloconverter that allows speed and direction control of the propulsion motors.

The pod's propeller usually faces forward because in this pulling (or tractor) configuration the propeller is more efficient due to operation in undisturbed flow. Because it can rotate around its mount axis, the pod can apply its thrust in any direction. Azimuth thrusters allow ships to be more maneuverable and enable them to travel backward nearly as efficiently as they can travel forward. In order to get the most out of it, shiphandling training on simulators and manned models is required.

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