I’ve been cruising around Norway for the past 6 days and met up with the folks from Rolls-Royce and Norwegian tug operator Buksèr og Berging who gave me a first-hand look at their two new LNG-powered tugs which are servicing Statoil’s Kårstø processing plant just north of Stavanger.
This facility collects and processes hydrocarbons from 30 fields offshore Norway and receives upwards of 700 vessels per year. It is the world’s 3rd largest LPG terminal.
The two tugs are powered by lean-burn LNG-fueled C26:33L6P engines from Rolls-Royce, with a combined output of 3410kW at 1,000 rev/min. They are the first tugs in the world to be 100 percent LNG-powered. The engines drive a pair of z-drive azimuthing 3,000 mm thrusters.
They come at a higher building cost than conventional tugs, and subsequently higher contract rates, however they provide an far more environmentally-friendly option – one specifically requested by Statoil and delivered by Buksèr og Berging’s engineering staff, along with Rolls-Royce.
Steering these tugs is super straight-forward as long as you understand that the thrusters operate like a tiller, not like a steering wheel. The tug turned on a dime and was extremely responsive – although I must admit, this was the first time I had ever stood at the helm of a tugboat.
Arild Jaeger notes that his company performs around 1500 escort jobs and assists around 4500 vessels every year from their fleet of mostly in-house designed tugs. His company has long-term service contracts with seven Scandinavian terminals.
The following image shows what an active escort is:
Essentially, the tug has a huge fin built into the bow and running aft to roughly amidships which allow the hull of the vessel to be used as a steering mechanism to greatly enhance the pulling effect of the tug.
The Bokn and the Borgoy have a bollard pull capability of 70 tons, however they each have a steering pull capacity of 120 tons at 10 knots.
Jaeger notes that escort tugs are required when hazardous cargoes move in and out of port.