LNG carrier propulsion has traditionally beenrnbased on a steam turbine power plant. Thernmain reason for this has been the ability tornutilise cargo boil-off gas as fuel. Thisrnpropulsion system is also considered to bernvery reliable. However, the economical andrnenvironmental disadvantages of steam turbinernpropulsion are driving operators to seekrnalternative means for LNG carrier propulsion.rnHandling of the boil-off gas sets therntechnological limits for alternative LNGrncarrier propulsion system. Recentrntechnological advances have finally broughtrnsome solutions that enable to displace thernsteam turbine propulsion. One technology isrnbased on reliquefaction of boil-off gas, thernother on using it as a fuel.rnIn addition to operating economy andrnenvironmental issues, also the very specialrnrequirements of LNG carrier operation have tornbe considered carefully when selecting thernpropulsion power plant. Safety andrnredundancy are the most important featuresrnrequired from the alternative power plant.rnElectric propulsion based on W?rtsil? dual fuelrnengines is shown to be a strong alternative forrnLNG carrier propulsion system (figure 1).
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