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Leading maritime solutions and services provider, Wärtsilä, says it has successfully conducted full scale testing on gas of its low-speed 2-stroke dual-fuel engine and is now introducing a full new range of engines based on its low pressure technology.

According to Wärtsilä, the implications of this for ship owners and operators are such that the new engine is already being referred to as a 'game changer' for merchant shipping.

The first engine utilising this technology, the Wärtsilä RT-flex50DF, will be available for delivery in the third quarter of 2014. Other engines from the company's new Generation X series will follow and will be available for delivery during 2015 and 2016.

Offering a broad range of benefits

The entire portfolio of Wärtsilä 2-stroke engines will be available as low pressure dual-fuel (DF) versions.

Wärtsilä says the benefits of this technology are 'significant'. Compared to other technologies, studies are said to show that Wärtsilä's low pressure DF engines offer capital expenditure (CAPEX) reductions of 15-20 percent. This is achieved through a substantially simpler and lower cost LNG and gas handling system operating at pressures below 10 bar, and by the fact that no further exhaust gas cleaning systems are needed to meet future emission regulations. The new engines are IMO Tier III emissions compliant in gas mode, and the minimum Tier II level is achieved with liquid fuel.

Furthermore, on the operating expenditure (OPEX) side, Wärtsilä's says that significant gains will be achieved with its technology. This is because no high pressure gas compression system external to the engine needs to be operated onboard the vessel, and NOx abatement systems are not required. Another main advantage, according to Wärtsilä, is that its technology allows stable operation on gas across the entire load range. This means that at low loads, there is no need to switch to diesel fuel as is the case with other technologies. Moreover, the consumption of pilot fuel is approximately just one percent of the total fuel amount, and therefore much lower than with other technologies, Wärtsilä says.

Martin Wernli, Vice President, 2-stroke, Wärtsilä Ship Power, commented: "The benefits of the new low pressure dual-fuel technology for 2-stroke engines are significant. Describing this as a game-changing development for merchant shipping is certainly no exaggeration, since the many advantages of being able to use gas and LNG as primary fuel are now, for the first time ever, available to virtually all vessel types. Our well proven technologies for both the engines and the onboard gas and LNG handling systems, can now be applied to this wider market. With the adaption of low pressure dual-fuel technology to 2-stroke engines, Wärtsilä brings the proven advantages it has demonstrated in the 4-stroke, medium-speed DF engine market to its 2-stroke low speed engine customers."

Wärtsilä's low pressure gas system is said to fulfil all safety requirements.

Leading in dual-fuel engine technology

Wärtsilä is a pioneer in the development of dual-fuel engine technology. Throughout the years, Wärtsilä's R&D work has focused heavily on these technologies. Wärtsilä successfully introduced its low pressure dual-fuel engine technology for 4-stroke engines for land based applications in the 1990s, and for marine applications soon afterwards. Since then, the company has delivered more than 1,000 such dual-fuel engines accumulating more than 7 million running hours.

"The application of natural gas as a widely accepted fuel for merchant shipping is likely to become a reality in the near future. The environmental benefits and attractive pricing that gas offers are expected to drive demand, with a resulting increase in market share for gas fuel. By introducing low pressure 2-stroke DF engine technology, Wärtsilä is accelerating this major trend since it makes the application of gas as a marine fuel easier and safer for owners, operators and yards. Wärtsilä envisages that by 2020, more than a quarter of the ordered vessels could be designed to run on gas fuel," Wärtsilä said.

Wärtsilä is currently in the process of finalising the documentation for the first of the new series of engines, the Wärtsilä RT-flex50DF. Preparations for Classification Society approvals are said to be underway.