For years, the maritime industry has been working hard to clean things up and minimize vessel emissions. Sustainable solutions are particularly in demand in sensitive ecosystems such as the Wadden Sea, which was declared a World Heritage Site in 2009. Dutch shipping company Doeksen is setting a good example by deploying two single-fuel, natural-gas-powered ferries in 2019, which will cut pollutant emissions by a significant margin. They will be powered by MTU's new mobile 16-cylinder single-fuel gas engines.
The view from Paul Melles' office window has evoked a lot of envy down the years with its panorama of the Wadden Sea which runs between the northern Dutch coast and the broad, sandy islands that guard it. On a good day, the island of Terschelling stretches out to the right, with its smaller counterpart, Vlieland, to the left. Halfway between them is a sandbank called Griend, which doubles up as a bird sanctuary. In front of his large picture window, the managing director of Dutch shipping company Doeksen, which operates ferry services to the two islands from its base in Harlingen, has set up a large tripod, and when he needs to take a moment out from his busy work schedule, he puts his eye to the telescope and surveys the scene laid out in front of him. “It's a great place to switch off,” says the 58-year-old. “And there's always something to see.”
Soon Melles' gaze will be resting every day on something he has been looking forward to for some time now: two new ferries the company ordered from the Strategic Marine shipyard in Vietnam back in April 2016. The company currently operates three ferries bringing both vehicles and passengers to the islands, plus two fast ferries, one catamaran for RoRo freight vehicles only, and a water taxi. The MS Midsland, one of the older ferries, is soon to be retired.
“We were looking for a new ferry concept that was both sustainable and innovative,” explains Melles, who used to be a seaman himself, later becoming Technical manager, and finally Managing Director of Doeksen in 2001. After a strategic study, those responsible decided to build two smaller catamarans instead of one large ferry, which not only makes the timetable more flexible, allowing more services to and from Terschelling, but ultimately also boosting efficiency, thereby also lowering operating cost. The study recommended single fuel LNG (liquefied natural gas) as the fuel of choice with the option of using BIO LNG or LBG (Liquified Bio Gas) in the future.
Newly-developed gas engine wins the day
It is of great concern to the managing director to minimize Doeksen's environmental footprint. “Climate change cannot be denied, and we simply have to do something,” he stresses. “We have a wonderful landscape and seascape right here on our doorsteps – the Wadden Sea is a world natural heritage site. Most passengers who use our ferries come here because of the beautiful natural surroundings – the lovely islands and the clean, fresh sea air.” The shipping company plies these routes frequently, so it has to take care of the environment. “This is what sets us apart. And it's why we should treat this place with care,” Melles continues. This includes things like using green electricity at all company sites, heating the terminal in Harlingen with a CO2-neutral pellet heating system, and reducing emissions given off by the fleet. Above all, however, it was clear from the outset that the two new vessels had to be equipped with environmentally-friendly propulsion systems. “Full Electric propulsion was not an option for us yet, given the battery systems currently available on the market,” explains Melles. “Terschelling is 21 nautical miles from Harlingen, meaning we would have to recharge the batteries after every trip. We just don't have that amount of time, and it's why LNG is the optimum solution for us right now.”
Compared with the gas oil normally used on our ships, liquefied natural gas has the advantage of giving off significantly less in the way of hazardous emissions. In fact, carbon dioxide emissions can be reduced by up to 10 percent, and nitrous oxides by up to 90 percent, while zero amounts of sulfur are given off, and particulate emissions are eliminated almost entirely. “When we started designing our new ferries, we knew MTU was developing a gas engine,” says the Doeksen boss. “But it wasn't quite ready, and the word was, initially, that it probably wouldn't be finished in time.” As a result, the company's managers began looking around for other options – while, at the same time, MTU techies in Friedrichshafen were pressing ahead with the development work. Their rapid progress and enthusiasm finally tipped the scales for Paul Melles: “We know MTU as a top-notch manufacturer of high-performance diesel engines that are extremely reliable. And even though this is a completely new product that has yet to establish itself, we are entirely convinced of the merits of the new gas engine.”
Challenges along the way
The few LNG-powered vessels already operating in other waters are mostly equipped with dual-fuel engines – meaning they can operate on diesel or gas as required. “This is an option we don't need, because we have a fixed route from A to B and back again,” says Melles. “MTU has developed the first single-fuel high-speed gas engine that can directly and mechanically drive a fixed pitch propeller, with transient acceleration capabilities comparable to that of a typical high-speed diesel engine. On top of all the enthusiasm and zeal of those involved, this was a major argument that really won our hearts and minds.” And so, Doeksen's two new 70-meter-long catamarans are to be fitted with MTU's new 16-cylinder Series 4000 gas engines, each with an output of 1,492 kilowatts, and will soon be ferrying up to 600 passengers and 64 cars across the Wadden Sea at speeds of up to 14 knots.
In the meantime, it was not quite clear whether the pilot project would actually be brought to a successful conclusion. Initially, certification of the mobile gas engine by Lloyd's Register, the maritime classification society, took longer than originally thought. “That was a major challenge,” says Melles, “but I have to take my hat off to MTU. They managed to speed up the processes and obtain certification in good time. That really was a great job.” Subsequently, the shipyard in Vietnam ran into financial difficulties and stopped work on the new ferries for three months. For Melles, who visited the site every six weeks or so during the entire construction period to check progress, this was a tough, exhausting time – until the banks finally agreed on new project financing, allowing it to continue.
The anticipation rises
It is now planned that the new additions to the fleet, the Willem Barentsz and the Willem de Vlamingh – named after two Frisian seafaring explorers – will arrive in Harlingen at the end of May 2019 and then, following commissioning and various tests, will commence initial trial sailings in December 2019. After that they will both be included in the new timetable as the main car ferry service on 7 January 2020. In the meantime the necessary infrastructure changes to Harlingen harbor will have been completed, including a new overnight berth for an additional vessel, minor adjustments to the pier for safe berthing and bunkering for weekly refueling. Paul Melles can hardly wait to take delivery of the new cats: “I've been working on this since the very beginning, these are my babies. It's really exciting to see something that started out as an idea being taken through to implementation. We've waited so long for this, and now it's all coming to fruition.”
For the 58-year-old, who lives 33 kilometers from his workplace and uses an Opel Ampera with an electric motor for his daily commute, there is no way he is going to miss the maiden voyage. As a former seafarer, he likes to be out on the water whenever he can – at weekends and during vacation time, preferably on his own sailboat. And during working hours, he will continue his efforts to keep the Doeksen fleet as clean as possible. He sees LNG very much as a transitional fuel. “This is a good, practical transition fuel, but a fossil fuel nonetheless, and thus finite,” he says definitively. At some point there will be working solutions for electric propulsion, perhaps also for hydrogen drive systems. But until then, he's got another idea: bio-LNG – gas produced and liquefied in biogas plants. “This would enable another major reduction in CO2 emissions,” he says. “There is the potential to obtain this in the area. And that's what we're looking into now: that's our next goal.”
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