Ferry to Sail Clean Through World Heritage-listed Waters
Wärtsilä has been awarded an important retrofitting contract by the German shipyard, BVT-Brenn-und Verformungstechnik Bremen GmbH to convert the Ostfriesland, a car and passenger ferry (owned by Aktien-Gesellschaft ‘EMS’) to run on liquefied natural gas (LNG) fuel.
Ferry MV Ostfriesland: Photo courtesy of Wärtsilä
The ferry’s route is between Emden and Borkum Island on the Lower Saxon Wadden Sea National Park, an ecologically sensitive UNESCO World Heritage listed area in the southeastern part of the North Sea, and the retrofit will significantly reduce the ship’s environmental impact.
The Ostfriesland’s diesel-electric configuration will be powered by two 6-cylinder Wärtsilä 20DF dual-fuel generating sets utilising a Wärtsilä proprietary LNGPac, which is a complete system that comprises onboard liquid natural gas bunkering, storage tanks, and handling equipment with related safety and automation systems. The scope of supply also includes Wärtsilä’s patented Cold Recovery System, which utilises the latent heat of LNG in air conditioning systems, thus reducing the amount of electricity consumed in cooling compressors. Significant operational savings and an increase in overall vessel efficiency are the result.
The medium speed 20DF dual-fuel engines with a cylinder bore of 200 mm will run primarily on LNG as the main fuel, but have the capacity to switch to conventional liquid fuels if necessary.
In general terms LNG bunkering takes place from the bunkering station to the LNG tank via an insulated pipe. The LNG tank connection space compartment is mounted directly on the LNG tank which contains all the piping penetrations through the tank shell, as well as all heating media connections to the LNG evaporators.
Example of LNGPac installation: Image courtesy of Wärtsilä
The process inside this tank connection space includes all the connections and valves between the tank and the Pressure Build-up Evaporator (PBE), and between the tank and the Main Gas Evaporator (MGE), together with the evaporators themselves, although Wärtsilä say that the LNGPac gas supply system can be customised according to specific requirements. The evaporators are heated by glycol-water circulating within a glycol-water heating unit.
The Wärtsilä contract was signed in April 2013 and the work will be carried out during the second quarter of 2014 for about seven weeks.
“It is of the utmost importance for us to operate the ‘Ostfriesland’ in the most ecologically friendly manner possible, with low exhaust emissions, perfect manoeuvrability, and high reliability. Thanks to Wärtsilä’s dual-fuel technology with its built-in redundancy, the vessel will be able to operate without restrictions in the SECA and NECA sulphur and nitrogen controlled areas …” says Dr. Bernhard Brons, Member of the Board of AG ‘EMS’.