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LNG ferries are here to stay

Wärtsilä believes that LNG is the future of shipping. And, as concern for the environment continues to grow, while the regulatory landscape becomes ever stricter, more and more vessel operators around the world are starting to agree.

Text: ISABELLE KLIGER Photo: Wärtsilä

Passenger vessels represent one of the most promising opportunities for LNG shipping. Not only do these vessels typically remain near the coast – and therefore close to the all-important fuel source – they also tend to operate in Emission Control Areas (ECAs), where clean fuel is not an option but a must. Twentyfour7. has taken a closer look at two of the world’s first LNG-powered passenger vessels – Viking Line’s Viking Grace and Reederei Cassen Eils GmbH’s Helgoland ferry.

World’s largest LNG-powered passenger ferry 

Delivered in 2013, the Viking Grace was the largest LNG-powered passenger vessel at the time. With its ground breaking dual fuel technology supplied by Wärtsilä, the vessel can operate without restrictions in SECA (Sulphur Emission Control Area) and NECA (Nitrogen Oxide (NOx) Emission Control Area) sulphur and nitrogen monitoring areas.

Wärtsilä’s scope in the project included the supply of four 8-cylinder, in-line Wärtsilä 50DF main engines, the transverse bow and stern tunnel thrusters, as well as two stainless steel fixed pitch propellers with propeller shaft lines, including environmentally sound shaft line seal systems, the LNG tanks and fuel supply and handling equipment with safety and automation systems. Wärtsilä also supplied a sound-absorbing system to minimise noise generated by the engine, thus increasing passenger comfort. A low noise level is also of importance due to the route of the vessel, which passes through the Turku and Stockholm archipelagos.

“We’ve been working with Wärtsilä for many years, and most of our ferries are already fitted with their engines,” says Kari Granberg, Manager NB Project and Technical Development, Viking Line. “However, apart from being the natural choice, Wärtsilä also presented the best proposal, from the point of view of both of technology and cost – so it was an easy decision to make.”

In 2007, when Viking Line first started looking into building a sustainable new vessel, choosing the right fuel was not as straightforward as it might seem. 

Securing LNG supply

“We didn’t like the idea of using Heavy Fuel Oil (HFO) with a scrubber for environmental reasons, while marine gas oil was too expensive. LNG was an option but, at the time, there was no supply of LNG in the Baltic Sea – so we were in a bit of a tight spot,” continues Granberg.

The choice of LNG was facilitated when Viking Line’s gas supplier AGA decided to build an LNG terminal in Nynäshamn, south of Stockholm. This terminal has been the exclusive provider of LNG to the Viking Grace since it was delivered in 2013.

Three years into its service life, the Viking Grace is approaching 24,000 running hours, and Granberg confirms that he is extremely satisfied with its performance for a number of key reasons.

LNG is sustainable and efficient

“The first and most obvious reason is the environment benefit,” he explains. “Running on LNG enables us to reduce greenhouse gas emissions by more than 15%, NOx emissions by 92% and particle emissions by 84%. Meanwhile, sulphur emissions are close to zero.”

There are also efficiency gains to be made from an LNG engine. Despite being 60% larger than the average Viking Line vessel, the Viking Grace uses only 16,000 tonnes of LNG per annum compared with the 24,500 tonnes of HFO consumed by the smaller diesel vessels. What is more, the Viking Grace also requires significantly less maintenance. While maintenance is typically done on an HFO engine after 16,000 to 18,000 operating hours, Wärtsilä’s dual-fuel engines require maintenance after 24,000 hours.

The Viking Grace is covered by a five-year maintenance agreement with Wärtsilä. As part of this agreement, Wärtsilä provides a broad range of services for the vessel, including engine maintenance planning, maintenance work, condition monitoring, spare parts supply, technical support and workshop services. The objective is to extend service intervals, while improving the logistics for spare part deliveries, and ensuring optimal operating efficiency and fuel consumption, thereby reducing costs.

Granberg also explains that the engine room on an LNG-powered vessel is cleaner than a conventional engine room. It requires less day-to-day maintenance and, as a result, fewer crewmembers are needed. In addition, the Viking Grace consumes only 18% of the amount of chemicals and 20% of the lubricant of Viking Line’s other vessels.


“If we were building a new vessel today, we would definitely go with LNG again,” confirms Granberg.

First LNG-fuelled German ferry

An even more recent addition to the LNG ferry fleet is Cassen Eils’ Helgoland ferry, the first-ever newbuild LNG-fuelled German seagoing vessel. Powered by a complete Wärtsilä LNG propulsion solution, the ship completed its maiden voyage on 11 December 2015. Operating between Cuxhaven and the island of Helgoland, the ferry’s route takes it close to the UNESCO World Heritage-listed Wadden Sea National Park, an ecologically sensitive area in the southeastern part of the North Sea. In order to minimise exhaust gas emissions, the Helgoland ferry operates primarily on LNG using two 9-cylinder Wärtsilä 20DF medium-speed dual-fuel engines. 

“We are very proud to be operating the first newbuild German vessel fuelled by LNG,” comments Dr. Bernhard Brons, Managing Director of Reederei Cassen Eils GmbH and CEO of AG EMS. “Compared with conventional diesel fuel, this ship will produce 20% less CO2, 90% less NOx, and almost zero SOx and particulates. Thanks to Wärtsilä’s dual-fuel technology with built-in redundancy, the vessel can operate efficiently and without restrictions in the Wadden Sea National Park. Furthermore, it was very important for us to select a reliable and experienced partner who was able to deliver a complete propulsion package.”

Wärtsilä has also retrofitted AG Ems’ Ostfriesland with two gas-powered, dual-fuel, 6-cylinder in-line Wärtsilä 20DF engines. The MS Ostfriesland, which re-entered service after conversion in the spring of 2015, also operates close to the Wadden Sea.

“The owners of Cassen Eils went for LNG because they wanted the cleanest and first zero-emission ship in this area. It was also important for them to find an experienced partner with a strong understanding of the short sea passenger shipping business,” says Matthias Becker, General Manager Marine Solutions, Wärtsilä Germany.

LNG is the future – in spite of cheap oil

“In my opinion, LNG is the shipping fuel of the future,” continues Viking Line’s Granberg, adding that he maintains this opinion in spite of the low cost of oil at the present time. 

“If you take a short-term view and base your decision on the current oil price, the alternative would be to use HFO with a scrubber. While this option cuts sulphur emissions, it doesn’t have any of the other environmental benefits of LNG,” he says.

“I think it’s highly unlikely that oil will remain at its current price for very long. Taking a more long-term view, I’m convinced that LNG will, once again, be the most sustainable AND cost-effective option on the market,” concludes Granberg. 


100 BC

Canadian operator BC Ferries is in the process of building the second in a series of three new Ropax ferries at the Remontowa shipyard in Poland. As more and more ferry operators are opting for gas, this build hardly seems novel. However, one of the three 8-cylinder Wärtsilä 20DF engines destined for installation on this ferry will be the 100th Wärtsilä 20DF dual-fuel engine built, just 4.5 years after the first one was shipped from the factory. 

“Once again, the advantages of Wärtsilä’s dual-fuel technology, and the fuel flexibility and environmental benefits delivered by this technology, have been emphasised with this milestone 100th delivery. The Wärtsilä 20DF shows that these benefits are as important for auxiliary applications, such as generating sets, as they are for main engine applications,” says Stefan Wiik, Vice President, Engines, Wärtsilä Marine Solutions.

The 100th Wärtsilä 20DF engine is to undergo its Factory Acceptance Test (FAT) within the coming weeks with representatives from BC Ferries in attendance.

“We congratulate Wärtsilä on this milestone delivery. We take our responsibilities for environmental compliance very seriously, which is why these additions to our ferry fleet will operate primarily on liquefied natural gas. The Wärtsilä dual-fuel technology is highly advanced and well proven, and we are confident that the Wärtsilä 20DF engines are the right choice for this application,” says Mark Wilson, Vice President, Engineering, British Columbia Ferry Services Inc.


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