Large, two-stroke engines powering global merchant shipping are here to stay for the foreseeable future.

Engines designed within the next 5-10 years will still be in use by 2050 and beyond. The economies and practicalities of power at such scale, combined with the energy storage required for the sheer geographic distances involved cannot be replicated through alternate sources. At least so far.

For now, progress within the industry must continue to reduce the environmental impact, mostly via exhaust emissions, of marine vessels burning fossil fuels.

Wholescale reduction in the emission of Green House Gas (GHG) emissions and other air pollutants is no easy task. It may well be that a tangible net-reduction in overall GHGs from merchant shipping will need to comprise a dynamic interplay of:

• Increased engine efficiency, through engine design modifications, hybridisation of the engine, co-generation of power via a Power Take Off (PTO) or waste heat driven power generation systems
• On-board emissions abatement, or partial-abatement
• Burning of reduced-carbon or carbon-neutral fuels, both in liquid and gaseous forms

It is clear that if large scale merchant shipping is going to reach the IMO GHG reduction targets, it will require advances in engine design, innovative new fuels (and other energy storage alternatives), and a willingness on the part of the shipping companies to invest in both. What is even more clear for engine designers, is that doing as much as possible to reduce the net-carbon emissions of the engine itself, will represent a unique and powerful selling point to the ship-owner.

We have already made great strides to this end since the introduction of the Otto-Cycle gas powered two-stroke engine in 2013. The burning of Liquefied Natural Gas (LNG) in the Otto-Cycle not only propelled these engines into Tier III SOx and NOx emissions compliance, but also represented a reduction in carbon emissions of approximately 15-20% when compared to burning liquid fuels. The popularity and uptake of these engines into the marketplace speaks for itself.

That success aside, there still remains the question: can engines be designed today, that will fit with future technology and be suited for retrofit PTO or hybrid propulsion systems too?

Therein lies the focus of much of the R&D effort at WinGD. Specifically exploring the alternative fuels landscape. We have been actively collaborating with industry experts through our testing facilities, including the use of renewable fuels in our engines since 2012. To this end, we have been working with universities and commercial ventures alike, with funding from both the Swiss Government and the European Union. Through these partnerships, the renewable fuel market has been closely observed, potential fuels identified, and in some cases co-developed, before being subject to further research.

Having successfully integrated both the Otto and the Diesel-cycle combustion principles into the engine portfolio, we can apply the best combustion strategy to each fuel candidate. As a result of this research flexible fuel injectors for our engines were developed, allowing for the use of multiple renewable fuel varieties.

We can also gain further understanding of the impact on combustion and the handling and injection aspects of any future fuel. This allows us to assess if these fuels will fit into existing hardware, or if any engine modifications are required. With the evolution and development of new fuel types/combinations, due consideration is also given to the significant role cylinder lubricants play in this scenario.

Historically, two-stroke marine cylinder lubricants have performed three main functions: to physically lubricate the running parts, to neutralise any acid generated during combustion of sulphur containing fuels, and to keep the piston running components clean. While reciprocating engines will always require physical lubrication of some sort, they may burn alternative fuels, incorporate abatement of acid neutralisation and engine cleanliness and continue to evolve as alternative fuels are developed. In the context of traditional lubricant roles, renewable fuels may combust or behave in ways unlike conventional fossil fuels, requiring modified or even bespoke lubricants.

Our ability to work closely with partners like ExxonMobil enhances our understanding of future fuel and lubricant characteristics, and their combined impact on engines to ensure reliable and efficient operation.

The road to the future isn’t completely clear but what is certain is that partnerships and collaborations are the key enablers for the strong, decisive planning and action that is needed now. The potential of the technological advancements as a result has the capacity to be the transformation the industry needs.