**UPDATE 15 Jan 12**: The Costa Concordia does not have azimuthing “pod-type” thrusters.
Many modern cruise ships are unique from other ships such as tankers, containerships, and most warships, in the fact they do not have rudders. Quite a number of these vessels use high voltage (11KV or 6.6KV) electrically-powered motors located outside the hull which turn the propeller. Because they are fed by electricity, and not by a drive shaft originating from inside the hull, these motors are able to pivot (or azimuth) in any direction, eliminating the need for a rudder. This also makes them highly efficient and eliminates the need for tugboats while entering or leaving port.
Reports indicate that the captain of the Concordia, Francesco Schettino announced that the ship was experiencing electrical problems at the time of the grounding. Considering that the ship was leaving port, and the engines are driven exclusively by electric power, a loss of power to the engines may have resulted in a complete loss of steering.
But would it?
International regulations require a backup power system for the ship’s steering system. Had the Costa Concordia lost power to the electrical bus feeding the engines, the backup power system should have kicked in immediately and the ship may have had the opportunity to maintain a safe outbound course.
The exact location of the ship versus the location of the outbound channel at the time of the incident is still not exactly clear, but whatever their position, the ship managed to get a massive rock embedded in the hull…