Sanmar built the world’s first LNG tugboat. The vessels were ordered by Buksér og Berging AS of Norway. The LNG tugboats began their service in 2014.
Tugboats are normally fueled by diesel. However, this fuel produces a number of polluting emissions. The new vessels, Borgøy and Bokn, are designed by the Norwegian tug owner Buksér og Berging AS. These are the first tugs to be fueled by the much more environmentally friendly LNG to eliminate sulfur emissions, bring particulate matter emissions down and minimize the discharge of CO2 and NOx .
Powering each of the new tugs is a pair of lean-burn gas engines from Rolls-Royce Bergen. These powerful gas engines are particularly robust, with a high degree of reliability and long intervals between overhaul. The lean-burn principle delivers high efficiency and low specific energy consumption. The engines are direct coupled to Rolls-Royce drives mounted aft in ASD configuration. The propellers have diameters of 3,000mm.
The two new 35m LNG fueled terminal tugs are trailblazers in this sector of the marine market demanding a significant step-forward in technical know-how above that of the average shipyard. Always at the forefront of innovation and technological advance, Sanmar now has a distinct lead on all other specialist shipyards in the search for more eco-friendly and economic tug operation.
This LNG tug meets the International Code of Safety for Gas Fueled ships and the DNV Classification Society rules. These involve such requirements as independent engine room spaces with ventilation of 30 air changes per hour, gas detection, automatic shutdown of gas supply and disconnection of electrical equipment, excess flow shutdown, ventilated double (sheathed) piping. Other special knowledge has been incorporated into the installation of the Aga Cryro AB 80m3 capacity double walled tank, cold boxes and gas heating systems.