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Royal Caribbean's Oasis of the Seas, the largest cruise ship ever built, has completed its maiden voyage across a stormy Atlantic Ocean, driven by an energy-efficient power and propulsion system from ABB.

Royal Caribbean's newest vessel crossed the Atlantic last week and was delivered to its owners in Miami, in time for its first commercial Caribbean cruise in December.

Weighing in at 220,000 tons and costing an estimated $1.2 billion, the enormous ship posed a new set of challenges for its designers. Through close collaboration between the owners, RCCL (Royal Caribbean Cruise Lines), the ship builders, STX Europe, and ABB, the project set new standards in terms of maneuverability, comfort and fuel efficiency.

Operating a ship of this size in busy ports and out at sea, where weather conditions are not always favorable, requires a special solution. ABB delivered a tailor-made electrical propulsion system, comprising three 20-megawatt (MW) Azipod propulsion units, to provide the additional reliability and manoeuvrability required.

Installing the propulsion units was perhaps the greatest technical challenge for ABB - because of the additional Azipod unit, an entirely new software system had to be put in place - but the most time-consuming job was installing the electric cabling. There are 5,000 km of electric cables and about 100,000 electric points on the vessel.

In addition to superior manoeuvrability, ABB says its Azipods also deliver fuel efficiency with savings of around 10-15 per cent compared to conventional shaft-line propulsion systems, thereby reducing fuel costs and cutting greenhouse gas emissions.

Wärtsilä engine

The ship is equipped with a total of six Wärtsilä 46 engines, three 12-cylinder and three 16-cylinder engines, generating more than 96 MW.

Wärtsilä's engines are equipped with common rail technology. As the combustion and other process parameters can be adjusted for lower load ranges, smoke emissions are said to be reduced.