RINA unveils Mermaid ship propulsion concept

RINA has unveiled ‘Mermaid’, a new ship propulsion architecture designed to assist the maritime industry in decarbonization efforts. The concept aims to increase efficiency by allowing a vessel’s two-stroke main engine to serve as its primary source of electrical power, reducing the need for less efficient auxiliary engines.

The Mermaid system integrates a shaft generator, a propeller shaft clutch, and a battery energy storage system. When a ship enters a port, the propeller is disconnected via the clutch, allowing the main engine to continue running to generate electricity directly or charge onboard batteries. These batteries can then power ship systems or provide support during critical operations.

This hybrid configuration is intended to be fuel-agnostic and is being developed for tankers, bulk carriers, and container ships. RINA estimates that the architecture could save more than 1,000 tonnes of fuel annually in certain applications. The concept also addresses the challenges of ‘slow steaming’ by allowing propulsion power to be better matched to actual operating conditions, thereby reducing the need for excess engine capacity.