Rederij Doeksen’s new LNG catamaran Willem Barentsz has entered service. Its sister ship Willem de Vlamingh will follow in September. They are the first (single-fuel) LNG-powered ferries in the Netherlands.
They are also the first ships in the world in which single fuel LNG engines directly drive rudder propellers with fixed propellers. The ships will be deployed on the ferry link to the Dutch Wadden Islands Vlieland and Terschelling. The Willem Barentsz entered service on Friday 3 July.

The introduction of this new LNG ferry concept, combined with heat recovery, more efficient hull lines, lightweight construction, and solar panels means a significant reduction in harmful emissions: -10 per cent CO2, -90 per cent nitrogen oxides (NOx), -100 per cent sulphur oxides (SOx), -95 per cent particulate matter. The shipping company’s ambition is to progressively blend the LNG with bio LNG or LBG as soon as this becomes sufficiently available. This will make it possible to reduce CO2 emissions even further.

Bumpy ride

‘The road to this fantastic moment has been long and bumpy due to all kinds of circumstances, not in the least because of the corona crisis, but the result of all efforts is impressive and something to be proud of,’ says Paul Melles, director of Rederij Doeksen. ‘The Willem Barentsz differs from its predecessors in many ways. In this design we have always taken the guest experience and the vulnerable environment of the Unesco World Heritage site the Wadden Sea as our guide.’

Originally, the aluminium catamaran car ferry was supposed to be delivered at the end of 2017 along with sister ship MV Willem de Vlamingh. Vietnamese shipyard Strategic Marine suffered financial difficulties while constructing the vessels. This meant that although the keels were laid on on 15 July and 9 August 2016, the ships could not be launched until 8 and 12 January 2019. Finally, Doeksen decided to bring the ships to the Netherlands for finishing, but they suffered water damage during transport causing yet more delays.

Unique engines

BMT developed the vessels from concept to detailed design. Sylvain Julien, director of Naval Architecture, explains: ‘As always, it was a challenge to develop an all-aluminium vessel that complies with national regulations that are generally based on steel structures. Nevertheless, in addition to a carefully optimised hull shape, the end result shows the advantages in terms of low energy consumption and, specifically for Rederij Doeksen’s ferry routes, the low operational draught.’

For each of the two new ferries, Rolls-Royce Power Systems supplied two pure gas engines. The 16-cylinder MTU series 4000 engines have a power output of 1492 kilowatts and allow the ferries to reach a top speed of 14 knots, while their temporary acceleration capacities are comparable to those of a typical high-speed diesel engine.

‘We are pleased that the ability of our first single-fuel high-speed gas engines to directly drive a fixed propeller was one of the main reasons that convinced Rederij Doeksen to choose to work with us,’ says Knut Müller, Head of Naval and Governmental Business at Rolls-Royce Power Systems. ‘We would like to thank our regular partner Rederij Doeksen for the trust they have placed in our new technologies and wish the new fleet members all the best.’

Heat recovery

Residual heat usually disappears into the air or is dumped into the sea, but not on board the two new LNG catamarans. To re-use the heat present in the exhaust gases of the engine to drive an electric generator, the catamarans are each equipped with two efficiency PACKs from Orcan Energy, each of which generates a net electrical efficiency of up to 77 kW. The residual heat recovery system covers the entire energy demand for this bow thruster installation. As a result, the use of the two efficiency PACKs means an annual CO2 reduction of 318 tonnes each – a saving of 260,000 litres of fuel and 462,600 kWh per year.

The new construction project actively contributes to the theme “Sustainable development of ports and energy transition” from the Pioneer Programme Wadden Fund 2012-2013. The Wadden Fund awarded Rederij Doeksen a subsidy of € 1,207,500 for this project.