With the Wärtsilä 20DF, Wärtsilä is extending the benefits of dual fuel (DF) technology to cover the entire power range. The engine offers ship owners and operators a compact unit that brings all the advantages of fuel flexibility to auxiliary applications, such as generating sets or as the prime mover in smaller vessels.
Based on the well proven and reliable Wärtsilä 20 diesel engine introduced in the early 1990s, fuel flexibility means the engine can be optimized for constant speed generating sets, as well as variable speed mechanical drives, for main engine applications.
The Wärtsilä dual fuel engine capability enables ships to be operated on either conventional liquid marine fuels (LFO, HFO or liquid bio fuel) or LNG. The switch between fuels can be made seamlessly without loss of power or speed. Such fuel flexibility enables compliance with emission regulations in controlled areas, while giving operators the option of determining the fuel according to cost and availability.
When operating in gas mode, the Wärtsilä 20DF engine is already compliant with IMO Tier III regulations without any secondary exhaust gas purification systems. Also, when fuelled by gas, the SOx and CO2 emissions are notably reduced and smokeless operation is attained.
In liquid fuel oil mode, the Wärtsilä dual-fuel engines are fully compliant with the IMO Tier II exhaust emissions regulations set out in Annex VI of the MARPOL 73/78 convention. The engine is able to operate efficiently and economically on low sulphur fuels (<0.1% S), making it suitable for operation in emission-controlled areas.
Installed alongside Wärtsilä 34DF, 46DF or 50DF main propulsion machinery, a Wärtsilä 20DF generating set completes the multi-fuel engine room concept. Compact and light, the Wärtsilä 20DF is intended for use in those vessel types where the Wärtsilä 20 is currently installed.
As well as being an ideal mechanical-drive prime mover in smaller applications, such as small cargo vessels, ferries or tug boats, it is also an excellent choice for harbour generating set applications in a wide range of vessel types.
The latest development of the LNG infrastructure provides clear evidence of the increasing importance of LNG fuel to the marine industry. Wärtsilä has a lot of experience and know-how throughout the LNG value chain, and we are confident that their solutions are what we need for this latest expansion to our fleet.
Three new LNG-fuelled Ro-Pax vessels being built for Swedish ferry operator Stena RoRo will feature a broad scope of Wärtsilä solutions. The ships are under construction at China Merchants Jinling (Weihai) Shipyard and will operate with Wärtsilä engines and propulsion machinery when delivered in 2024 and 2025. The order was booked with Wärtsilä in Q4 2021.
Having a single supplier of a large scope package provides multiple benefits in the form of system compatibility, and seamless interfacing during the procurement phase of the project. This notably lessens the risk of project delays.
“We are very familiar with Wärtsilä’s ability to supply reliable and highly efficient solutions in line with our operational and sustainability requirements. In particular, their experience and leading know-how in LNG technologies is especially important to us as we move to decarbonise our services,” says Per Westling, Managing Director, Stena RoRo.
“We are delighted to help Stena RoRo bring the latest new vessels in its E-Flexer series to market, and to work once again with Wärtsilä to ensure these vessels have highly efficient and environmentally sustainable propulsion,” said Ni Weisong, Vice General Manager, China Merchants Jinling (Weihai) Shipyard.
“We have earlier supplied a similar scope of solutions for Stena newbuild projects, and it is especially gratifying to receive this repeat order. The cooperation between our companies and with the shipyard has been excellent, and we look forward to another successful outcome,” says Roger Holm, President, Wärtsilä Marine Power.
The vessels, each around 200 metres long, are part of a series of E-Flexer class ferries ordered by Stena RoRo for European line service. For each ship Wärtsilä will supply Wärtsilä 46DF dual-fuel main engines, Wärtsilä 20DF dual-fuel auxiliary engines, two gearboxes, two controllable pitch propellers (CPP), the tunnel thrusters, and the fuel gas supply system.
The use of LNG as a marine fuel is viewed by Wärtsilä as being an important transitional solution in the drive towards decarbonising shipping. LNG bridges the gap between conventional diesel fuels and future zero-carbon alternatives yet to be widely available, a decarbonisation strategy fully supported by both Wärtsilä and Stena Line.
Wärtsilä is working closely with Stena RoRo to ensure that one of the vessels meets DNV’s Silent-E class notification. This recognises that underwater noise from the vessel is controlled to protect vulnerable environments and involves careful configuration and design of propulsion and onboard equipment to offer low noise while maintaining high efficiency.
Wärtsilä will also supply the ships with Nacos navigation and automation, as well as integrated control alarm and monitoring system MCS Platinum together with the performance monitoring system. The vessels will also feature Wärtsilä’s Smart Panoramic Edge Camera System, eliminating blind spots and creating a 360°, birds-eye view of the ships surroundings, offering a significant advantage when docking.
The equipment is scheduled for delivery to the yard commencing in Q4 2022.
Stena RoRo specialises in custom-built vessels, as well as standardised RoRo and RoPax vessels. The company leases about fifteen vessels to operators worldwide, both to other Stena companies and third parties. Stena RoRo specialises above all in applying its technical expertise to the design and production of new ships and the conversion of existing ships for delivering tailored transport solutions to its customers.
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Image caption: Wärtsilä will provide dual-fuel engines and a wide range of other systems to three more E-Flexer vessels under construction for Stena RoRo © Stena RoRo
Wärtsilä in brief
Wärtsilä is a global leader in innovative technologies and lifecycle solutions for the marine and energy markets. We emphasise innovation in sustainable technology and services to help our customers continuously improve their environmental and economic performance. Our dedicated and passionate team of 17,500 professionals in 200 locations in more than 70 countries shape the decarbonisation transformation of our industries across the globe. In 2020 Wärtsilä’s net sales totalled EUR 4.6 billion. Wärtsilä is listed on Nasdaq Helsinki.