Hurtigruten cuts costs with propulsion retrofits
A series of propulsion retrofits over the past four years have cut fuel costs and emissions across Hurtigruten's 14 ships
Norwegian ferry and cruise operator Hurtigruten has revealed details of an extensive, multi-year retrofit programme to reduce fuel costs and cut emissions across its 14 vessels.
Four vessels – Richard With, Nordkapp, Nordnorge and Kong Harald – have received Promas Lite propulsion retrofits from Rolls-Royce between 2013 and early 2017. The work involved fitting a pre-fabricated bulb to the existing flap rudders, adding hubcaps and installing optimised blades on controllable pitch propellers. The work, which also aimed to reduce noise and vibration levels, cut fuel consumption by between 3.5% and 4.2% on the four vessels. The Norwegian government contributed 80% of the cost of the retrofits – which cost around NOK7 million per ship in total – from the NOx Fund after reductions in emissions were independently confirmed by DNV GL.
“This means the payback on investment is less than a year,” noted Tor Geir Engebretsen, chief operating officer and senior vice president maritime operations, Hurtigruten. “Without the NOx Fund contributions it would be a very different business case.”
A further three vessels – Midnatsol, Nordlys and Trollsfjord, have had main propeller systems changed from twin contrarotating thrusters to twin controllable pitch Azipull thrusters, also provided by Rolls-Royce. Four vessels – Polarlys, Midnatsol, Trollsfjord and Finnmarken – have received upgrades to meet Tier II NOx emission limits including new Napier turbochargers, modifications to cylinder heads on Wärtsilä engines and switching to single pulse exhaust systems.
Meanwhile, onboard its 90-series ships featuring MaK engines, the operator has been able to eliminate cylinder oil use. The vessels were originally intended to burn heavy fuel oil – before Hurtigruten switched to Shell’s 0.5% sulphur marine special diesel (MSD) across its fleet – and the owner worked with MaK to confirm that cylinder oil was not needed with the engines running on low-sulphur diesel. Engebretsen reported that the company had been able to reduce cylinder oil use on the vessels subsequently, reducing cost and emissions.
Further details of the Hurtigruten retrofit programme and its polar expedition newbuilds will be published in the May issue of The Motorship.