Liquefied natural gas has been used as marine fuel on ferries and other large vessels, but smaller workboats haven’t adopted the more environmentally friendly and less expensive LNG until now. The delivery of the Borgøy to Norway’s Buksèr og Berging from builders in Turkey sets a milestone as the first LNG-powered tug in the world.
Described as a “terminal tug,” the new boat is now working Statoil’s Kaarstoe Gas Terminal.
The 115'×50'×25' tug was designed in-house in partnership with Marine Design AS in Norway. Sanmar Shipyard in Istanbul, Turkey, also contributed to the engineering.
Another key partner for the innovative project was Rolls-Royce, which provided the propulsion package including Bergen engines, LNG systems and the propulsion units.
The two spark-ignited LNG engines are each rated at 1,705 kW (2,286 hp)@1,000 rpm. Each turns a 118"-dia., controllable-pitch, four-bladed CuNiAl propeller. Schottel provided the 333-kW (446-hp) bowthruster. Bollard pull is listed at 68 metric tons. Service speed is 13.5 knots.
The two 240-kW gensets are powered by Scania diesel engines.
A hydraulic, escort-capacity Karmoy towing winch on the bow has a drum capacity of 250 m and a line pull of 130 tons at 0-275 m/min.
Accommodations include six bunks in two single and two double cabins built to “North European Standards” including heated floors in the heads. Sound levels at 80 percent engine load are 60-65 dB in the cabins, wheelhouse corridors and mess area.
Using LNG fuel eliminates sulfur emissions, brings particulate matter emissions down close to zero and reduces the discharge of CO2 and NOx by 26 and 80-90 percent respectively.