Engine designer WinGD suggests that rather than concentrating on future fuels, new engine concepts and long-term decarbonisation pathways, shipowners need to address the more immediate question of reducing emissions from vessels currently operating.
With this in mind, the company has produced a new white paper, LNG-Fuelled Fleets Reducing Emissions: VCR retrofitting as a ready solution. It examines how Variable Compression Ratio (VCR) technology can be applied to existing LNG dual-fuel engines to deliver measurable emissions reductions within the timeframe set by the IMO’s 2030 targets.
The reality is that most of the ships trading in 2030 will not be newbuilds, meaning that decarbonisation solutions must extend beyond future engine platforms and focus on improving the performance of engines already in service. VCR is available as standard on X-DF2.0 engines and retrofit-ready for existing X-DF LNG dual-fuel engines. It is designed to enable shipowners to improve efficiency, reduce methane slip and extend regulatory compliance without waiting for fleet renewal.
Importantly, the solution can be applied to RT-flex50DF engines. There are around 50 engines in the global fleet that could be retrofitted, extending the benefits of VCR technology to a broader installed base of LNG dual-fuel vessels already in operation.
By dynamically adjusting the compression ratio in real time, VCR optimises combustion across varying loads and operating conditions. In practice, this translates into lower fuel consumption in both gas and diesel modes, alongside significant reductions in methane slip at partial loads.
A key design objective with VCR was to ensure it could be deployed with minimal impact on vessel operation. The system is fully integrated into the engine control architecture and requires no crew intervention. VCR retrofits can be carried out during scheduled dry-dockings. This allows operators to turn planned maintenance into a performance upgrade, avoiding additional off-hire time while delivering tangible environmental and commercial benefits.
According to WinGD, the commercial case for VCR is clear. Since its launch in 2023, more than 170 orders have been placed for VCR systems. While early uptake has been strongest in the LNG carrier segment, interest is broadening, with orders now spanning PCTCs, bulk carriers and container ships. The growing adoption is considered to reflect a wider industry realisation: improving the efficiency of LNG engines already in service is a fast and scalable way to reduce emissions this decade. For many operators, VCR can offer a practical way to deliver measurable results now, rather than waiting for future fuel pathways to mature.
VCR supports longer-term fuel strategies. While optimised for LNG today, the technology is compatible with future fuels, helping shipowners manage uncertainty while protecting asset value. It does not rely on unproven infrastructure or future regulation; it is claimed to deliver measurable improvements using technology that is available now, offering a credible path to reducing emissions, lowering operating costs and extending the useful life of existing assets.
The white paper, LNG-Fuelled Fleets Reducing Emissions: VCR retrofitting as a ready solution, explores the performance data, engineering considerations and real-world retrofit experience behind VCR in more detail and is available for download here.
Image: VCR can be retrofitted during normal drydocking (source: WinGD)
