The cruise liner MILLENNIUM built by Chantier l’Atlantique for Royal Caribbean/Celebrity Cruises has pioneering machinery installation. For the first time in merchant ships for some 25 years, gas turbines are used for the primary power. In addition, the ship features the first shipboard use of Mermaid podded propulsors. The power plant arrangement is based on the use of two General Electric gas turbines driving Brush alternators each delivering 25MW. These are supplemented by the output from a Fincantieri turbine which draws steam from a waste-heat boiler fitted in the exhaust lines from the gas turbines, to drive 9MW alternator.
59MW of electrical power generated in this way, 39MW is available for propulsion, with the rest satisfying all other shipboard needs. The MILLENNIUM is powered by Mermaid units developed by Alstom and Kamewa, which have the unique facility of shaft seals and the entire pod replaced while the ship is afloat.
Many “green” benefits are claimed from this novel propulsion concept, with NOx emissions reduced by 80%, and the use of higher quality fuel reducing SOx quantities by 98%. The internal space saved resulted in an addition 40 passenger and 20 crew cabins available. Reduced noise and vibration allows 26 cabins with aft-facing verandas to be built over the stern.