The Azipod system is an azimuthing electric propulsion drive where the propulsion motor is installed inside a submerged azimuthing (unlimited 360 degrees) pod and coupled directly to an extremely short propeller shaft. The variable speed electric (AC/AC) drive produces smooth torque over the entire speed range including zero speed. Azipod units are available in up to 25MW.
The picture shows 3 x 14 MW Azipod units for Voyager of the Seas, which is currently being built for Royal Caribbean International at Kvaerner Masa-Yards Turku Shipyard. Two of the units are fully azimuthing (360 degrees rotating) and the center unit is fixed (non-rotating) and integrated to the skeg.

The Azipod concept employed on a RO-Pax Vessel also provides distinct advantages. By placing the main diesels and the propulsion motors away from the cargo area an increase in cargo capacity can be achieved. The installed power in the ship is reduced due to improved hydrodynamic efficiency and the lack of auxiliary engines. Manoeuvring time in port is reduced resulting in reduced speed in transit or alternatively, more time for loading/off-loading.

More information: http://www.abb.com/fi