The BMT-designed 70m LNG ferries, distinguished by their 100% LNG-fuelled powerbase, are environmentally-friendly and affordable ROPAX solutions for Dutch company Rederij Doeksen, operating in the Waddenzee, a UNESCO World Heritage Site.

Managing director Paull Melles has led the company drive to reduce the environmental impact of the vessels. BMT has supported the focus by provided the technical solution to reduce NOx, CO2, and noise while increasing the efficiency of the design to achieve lower operational costs.

A number of newbuild options were considered to service the increasing traffic on the ferry route between Harlingen and Terschelling, resulting in the medium-speed aluminium catamaran platform being selected thereby achieving a significant reduction in fuel consumption compared to an equivalent monohull.

The development of the hull form followed a multi design criteria optimisation approach to account for the many constraints on the projects such as integration of the LNG containment systems and shallow water operation while offering the lowest possible power requirement across the ferry’s operational range. The outcome of this work was successfully confirmed through a series of shallow and deep water model testing.

Sylvain Julien, Director of Naval Architecture at Specialised Ship Design, BMT, commented “The development of a full aluminium vessel to meet national rules that typically assumes steel construction has, as always, been a challenge. Despite this, the end result demonstrates the benefits in terms of low power consumption, and specifically for Rederij Doeksen’s operation, the low operating draft”.

The new MTU pure gas engines provide both fuel efficiency and sustainability with no marine gas oils being required for operation (in contrast to the more usual dual fuel engines). The IMO Tier III and EU stage V compliant engines each deliver 1,500 kW and drive the VETH VZ contra-rotative unit to achieve a service speed of 14 knots.

Particular attention was paid to minimising energy consumption and reducing generator set sizing. Energy saving features include a waste heat recovery and battery system to power the vessel bow thrusters and provide peak shaving capabilities.

The 70m Doeksen ferry includes; maximum capacity of 600 passengers, 66 cars, 120m truck lane, and 6 crew members. The vessel operates at a service speed of 14 knots.

The BMT-designed sisterships ‘Willem Barentsz’ and ‘Willem de Vlamingh’ were built by Strategic Marine Shipyard (Vietnam) with final outfit and commissioning being completed by Rederij Doeksen.