Swedish port operator takes delivery of hybrid icebreaking tug

The Port of Luleå in Sweden has taken delivery of a newbuild Robert Allan Ltd-designed hybrid icebreaking tug from Spain’s Gondan Shipbuilders.

The 36- by 13-metre Vilja will be used in ice management, firefighting, and navigation aids service duties in the Port of Luleå as well as assist ships and conduct coastal towing in the northern sector of the Gulf of Bothnia.

The LR-classed vessel is equipped with a hybrid propulsion system featuring diesel main engines, shaft motor/generators, and electrical battery energy storage. It is capable of operating on the electrical battery power only or utilising a single main engine in the hybrid diesel-electrical mode, or on two main engines in diesel-mechanical mode with possible battery boost.

Main propulsion is a hybrid configuration with in-line shaft motor generators (M/Gs) and comprises of a pair of Wärtsilä 8L26 diesel engines, each rated at 2,720 kW at 1,000 rpm, and each driving a Rolls Royce US355 controllable pitch Z-drive unit, rated 3,100 kW at 1,000 rpm. The additional boost is provided by two shaft motor/generators, and electrical battery energy storage.

During trials, Vilja achieved a free running speed of 14.6 knots and bollard pulls of 89 tonnes in mechanical mode and 98 tonnes in boost mode.