Dual-Fuel Finds A New Backer

A long and determined endeavor to promote the dual-fuel engine concept in the deepsea LNG carrier sector, one of the last bastions of the steam turbine, has been rewarded by a powering deal covering a new breed of French gas tanker.

The installation selected for the 75,000-cu m newbuild contracted by Gaz de France at Chantiers de l'Atlantique not only gives Wartsila's DF series its head in the LNG carrier segment, but also signals a breakthrough for electric propulsion in the gas tanker market.

The four L50DF, six-cylinder dual-fuel engines will drive generators to meet the ship's entire electrical power needs for propulsion and shipboard services.

The machinery will maximize usage of cargo boiloff as gas fuel, and Wartsila claims that the high efficiency of the engine type promises much lower fuel consumption overall, and substantially lower stack emissions, compared with conventional steam turbine plant.

Rated at 5,700-kW apiece and derived from the successful Wartsila 46 medium-speed diesel, the engines allow for automatic switchover from gas to marine diesel oil in the event of an interruption to the gas supply, while continuing to deliver full power.

The Gaz de France project also represents another milestone as the first to adopt the CS1 membrane cargo containment system newly-developed by specialist engineering firm Gaztransport & Technigaz (GTT).

Due for handover by the St. Nazaire yard in 2004, the seminal class of LNG carrier will be allocated to the trade between Algeria and France, transporting LNG from Skikda to Fos, near Marseilles. The schedule calls for round-voyages of about one week at a service speed of 16-knots, achievable using three of the ship's four main gensets.

The vessel is also likely to be deployed for spot market fixtures, such as shipments to the U.S. For transatlantic passages, a speed of 18.5-knots should be attainable with all four gensets in operation.

Other stories from May 2002 issue


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First published in 1881 Maritime Reporter is the world's largest audited circulation publication serving the global maritime industry.