The merger of three Japanese engine and propulsion manufacturing giants holds considerable promise for continued R&D and technological advancements
When NYK Line’s pure car truck carrier (PCTC) Sakura Leader was delivered in late 2020, it achieved several milestones at once.
In a testament to Japanese maritime technology, Sakura Leader is powered by enginebuilder IHI Power Systems’ two-stroke, low-pressure Otto-cycle X-DF engine, built by Shin Kurushima Toyohashi Shipbuilding, and has a gas supply system from Mitsubishi Shipbuilding.
Capable of carrying 7,000 vehicles, Sakura Leader is the first large LNG-fuelled car carrier to be built in Japan, with a sister vessel to follow in 2021.
Providing the prime movers for the two car carriers represents one of the first plum contracts since the creation of IHI Power Systems (IPS) – literally a Japanese propulsion powerhouse – formed through the merger of three long-standing manufacturers: IHI, Diesel United and Niigata.
With a maximum power output of 11,920 kW, Diesel United’s DU WinGD 8X52DF represents the latest thinking in dual-fuel engine technology. According to the group, the low-pressure gas injection system is safer and cheaper, the latter because it reduces the cost of the gas supply system. The group also claims lower capital and operating costs because of the absence of a high-pressure compressor. For safety reasons, the engine uses low-pressure LNG.
Built under license from Winterthur Gas & Diesel (WinGD), the engine also ticks the boxes on IMO’s regulations on emissions and underpins the Japanese government’s policy on zero-emission targets in shipping. In fact, the government has designated the PCTC as a flagship project.
“The X-DF engine can produce less CO2, SOx, NOx and particular materials than general diesel engines,” a spokesman said. “Especially for NOx, this is a big point that X-DF [engines] can meet the regulation values without using post-processing devices such as exhaust gas recirculation and selective catalytic reduction.” The engine is now available in seven models. According to IPS’ spokesman, they range from the small X40DF to the large X92DF.
Diesel United and its technical partner, WinGD, are continually developing dual-fuel technology. As Marine Propulsion reported, in June 2020 the Swiss group unveiled an exhaust-recycling system for X-DF2.0, its second-generation dual-fuel engine platform that slashes methane emissions, the current target of policy-makers around the world, as well as of the IMO. The system is also claimed to boost the engine’s performance when fuelled by LNG and the emerging wave of carbon-neutral fuels.
Technically known as iCER, the system improves combustion control through the use of inert gas. “By adjusting the circulation rate of inert gas and controlling parameters like fuel admission and ignition timing, we can increase compression ratios for greater efficiency,” promises WinGD’s global director of sales, Volkmar Galke. “The result is optimised combustion through closed-loop control, regardless of ambient conditions and load.”
“Niigata is working on the world’s first ammonia-fuelled tugboat”
Meantime Sakura Leader is a tribute to NYK Line’s commitment to LNG. Over the next decade all its car carriers will be progressively switched to the fuel. NYK Line has also set itself a deadline of zero-emission sailing through the use of hydrogen and ammonia as fuels within the next 15 years. Given the close connections between the groups, it is certain that IPS will be involved in this mission.
At the opposite end of the scale, IPS subsidiary Niigata is working on another pioneering project – the world’s first ammonia-fuelled tugboat. In late 2020 the group signed with class society ClassNK and NYK Line to start the research and development and, if the technology adds up, move on to the construction of the vessel. NYK Line will be responsible for the design of the hull and fuel supply system. IHI Power will build the high-output engine and exhaust-gas aftertreatment, and ClassNK will conduct the assessment of the tugboat’s safety.
The Japanese powerhouse has high hopes for ammonia. “If it is possible to commercialise marine equipment that uses ammonia, a candidate for a next-generation fuel, and establish a method for operating the vessel, it is expected that the Japanese maritime industry will make a significant contribution to decarbonisation of the international shipping sector,” IPS announced in September in what amounts to a mission statement.
This latest project builds on an earlier successful collaboration. In 2015 Niigata delivered two four-stroke, dual-fuelled 6L28AHX-DF engines for the azimuth stern drive harbour tug Sakigake for NYK Line. Capable of operating on MDO and LNG, the engines drive two fixed-pitch ZP-31 Z-Peller thrusters. While burning MDO, the ASD tug can achieve IMO Tier II compliance, and in gas mode, IMO Tier III compliance. Since Sakigake’s delivery, 6L28AHX-DF engines have found their way into multiple dual-fuel tugs, such as KST Liberty, Maju Loyalty, PSA Aspen and Transko Rajawali.
The merger in 2019 put together a literal powerhouse of manufacturers – Diesel United, Niigata Power Systems and IHI under the umbrella of IHI Power Systems – that promises to have an important influence on ship propulsion in coming years. Each company will retain its own special expertise. IHI continues to develop the highest-tech forms of power, such as aero engines.
Diesel United specialises in large-bore diesel and dual-fuel engines for ships and land. Its space-saving Pielstick four-stroke has long been a favourite for cruise ships, car ferries and roros, in part because of its lower engine height compared with competing low-speed, two-strokes.
As for Niigata, it concentrates on small- to medium-sized diesel and gas engines as well as Z-Pellers. Niigata’s inventory boasts the latest dual-fuel engine installed on the Sakigake tugboat; the AHX series medium-speed diesel popular for offshore support vessels, tugboats, passenger ships and fishing boats; the big-selling HX medium-speed diesel that has been steadily improved over the years, for instance with fewer components, less vibration and noise; and high-speed diesel engines like the 500 kW 20FX developed for the Japanese navy’s patrol vessels.
Right from the start, Niigata has always prided itself on innovation – its PC4.2BV launched in 1933 was then the largest engine in the world, producing 23.8 MW, and powered large ferries and roro ships. Even now, the engine can be re-tuned to meet Tier II regulations. Niigata has been working towards cleaner engines for two decades. Back in 2008 it unveiled the 28AHX, a medium-speed diesel engine compliant with IMO’s Tier II regulations. Six years later, the manufacturer released the medium speed, dual-fuel AHX-DF that met Tier III regulations.
And with the extra resources of the merger behind it, other innovations surely lie ahead.