World’s First LNG-Powered Icebreaker Refuels at New Tornio LNG Terminal

[thackney]

World’s First LNG-Powered Icebreaker Refuels at New Tornio LNG Terminal
https://gcaptain.com/worlds-first-lng-powered-icebreaker-refuels-at-new-tornio-lng-terminal/
February 5, 2019

The world’s first LNG powered icebreaker, Polaris, has fueled up for the first time in Tornio, Finland, home to the Nordic countries’ largest liquefied natural gas terminal.

The bunkering took place Saturday, February 2nd, in the icy Röyttä Harbour.

The diesel-electric icebreaker, Polaris, joined the fleet of Finnish icebreaker operator, Arctia Ltd., in September 2016. The vessel operates under contract with the Finnish Transport Infrastructure Agency, which is responsible for Finland’s icebreaking services and for making sure that Finland’s harbors can be accessed throughout the year.

Use of LNG fuel makes the Polaris one of the most environmentally-friendly icebreakers in the world.

“This is the third winter in the demanding, icy conditions of the northern Baltic Sea for the world’s first LNG-powered icebreaker. Polaris has met our expectations with flying colors proving that it is truly a next generation icebreaker,” says Markus Karjalainen, Head of the Winter Navigation Unit of FTIA....

[Elderberry]

https://en.wikipedia.org/wiki/Polaris_(icebreaker)#Power_and_propulsion

Power and propulsion

Like all Finnish post-war icebreakers, Polaris has a diesel-electric power plant and propulsion system. However, she is the first icebreaker in the world to be powered by dual-fuel engines capable of using both low-sulfur marine diesel oil (LSMDO) as well as liquefied natural gas (LNG) as fuel. The dual-fuel power plant reduces exhaust emissions and complies with both IMO Tier III emission limits as well as the special requirements of the Baltic Sea Sulphur Emission Control Area (SECA).[66] In average winter conditions, the vessel has an autonomy time of 10 days when operating on liquefied natural gas, which is stored in two vertical tanks with a total volume of 800 cubic metres (28,000 cu ft). Fuel oil, stored in separate tanks with a combined volume of 2,500 cubic metres (88,000 cu ft), provides additional 20 days of endurance in similar ice conditions.[2]

The power plant, located amidships at the main deck level, consists of two 9-cylinder Wärtsilä 9L34DF and two 12-cylinder Wärtsilä 12V34DF four-stroke medium-speed dual-fuel generating sets fitted with exhaust gas economizers. The smaller straight engines are rated at 4,500 kW (6,000 hp) each while the bigger Vee engines have an output of 6,000 kW (8,000 hp) each. In addition, the vessel has one 8-cylinder Wärtsilä 8L20DF auxiliary engine, rated at 1,408 kW (1,888 hp), that can be used to produce electricity when the ship is at port.[67] The combined output of the electrical power plant, which can produce power for all shipboard consumers with any combination of generating sets depending on the power demand, is about 22.5 MW. There is also a separate emergency diesel generator.

Polaris features a novel propulsion system consisting of three electrically driven ABB Azipod propulsion units, one of which is located in the bow of the vessel. The stern propulsion units are rated at 6.5 megawatts each while the azimuth thruster in the bow has propulsion power of 6 megawatts. Each ice-strengthened Azipod unit has a four-bladed stainless steel propeller with removable blades and weighs 135 tons.[65] This new type of propulsion system was selected to fulfill the strict operational capability requirements set by the Finnish Transport Agency particularly in ridged ice fields.[68] The combined propulsion power of the three propulsion units, 19 megawatts (25,000 hp), makes Polaris the most powerful icebreaker ever to fly the Finnish flag as well as the most powerful icebreaker built specifically for escort operations in the Baltic Sea.

Based on ice model tests carried out before the vessel is delivered, Polaris is capable of continuously breaking level ice with a thickness of 1.8 metres (6 ft) at 3.5 knots (6.5 km/h; 4.0 mph) and maintain a speed of 9.2 knots (17.0 km/h; 10.6 mph) in 0.87-metre (3 ft) unbroken ice. While the ice in the northern parts of the Gulf of Bothnia does not get thicker than about 1 metre (3 ft) even during the hardest winters, the high icebreaking capability allows the vessel to operate efficiently in all prevailing ice conditions, particularly heavily ridged ice fields, and maintain a high average escort speed through the winter. In open water, the vessel has a trial speed of 17 knots (31 km/h; 20 mph).[2]

The icebreaker, which has a bollard pull of about 214 metric tons,[34] can also be utilized for emergency towing of stricken vessels.[2]