Classification society RINA has introduced a new ship propulsion concept designed to reduce reliance on auxiliary engines by using the vessel’s main engine to generate onboard electrical power, according to Ship & Bunker.
The concept, named Mermaid, was unveiled in a press release issued Thursday, as reported by Ship & Bunker. It combines a shaft generator, a propeller shaft clutch, and battery storage integrated with a vessel’s two-stroke main engine.
How the System Works
According to Ship & Bunker’s report on RINA’s announcement, the system allows the propeller to be disconnected from the main engine while the vessel is in port, enabling the engine to keep running solely to generate electricity or charge onboard batteries. Once the main engine is shut down, the charged batteries can continue supplying power to the ship.
RINA said the setup is intended to lower bunker fuel consumption, cut emissions, and reduce operating costs by making fuller use of the main engine rather than relying on separate auxiliary engines for power generation, Ship & Bunker reported.
The concept also has an application during slow steaming, where RINA said the system can help better match engine power output to actual operating conditions, according to the report.
Potential Fuel Savings
According to Ship & Bunker, RINA’s internal analysis indicates that Mermaid could save more than 1,000 metric tonnes of fuel annually in certain applications, though the specific vessel types or operating profiles used in that analysis were not detailed in the report.
RINA described Mermaid as fuel agnostic, meaning it can be applied regardless of the fuel type used, and said it is suitable for a range of vessel types including tankers, bulk carriers, and container ships, Ship & Bunker noted.
The report also states that RINA is now progressing the concept into a more detailed design phase, having gathered feedback from shipowners and shipyards.
Does This Matter to You?
Fuel efficiency technologies that reduce auxiliary engine use directly affect bunker fuel consumption patterns, which is relevant to vessel operators and bunker buyers tracking fuel demand and cost-saving retrofit options. A concept claiming savings of over 1,000 mt of fuel per year, if adopted at scale, could have implications for onboard fuel planning and emissions compliance strategies, particularly as the source notes applicability across tankers, bulk carriers, and container ships.
However, RINA’s concept remains in a developmental stage, with the design still being refined based on industry feedback, according to Ship & Bunker. The direct commercial or operational impact for the wider fleet is not yet clear from the available information.
Gulf Bunkering does not provide operational or security guidance. This article is for informational purposes only. Operators should consult flag state authorities, P&I clubs, and relevant advisories for decisions relating to transit planning.
Sources: Ship & Bunker
