A greener, more efficient rudder system designed at the University of Strathclyde is to be demonstrated as part of a €6m EU-funded research project. The GATERS project, led by the University of Strathclyde under the Horizon 2020 Fund, will see the ‘gate rudder’ – a novel propulsion and steering system – retrofitted to a commercial vessel as part of a trial.
Unlike a traditional rudder, which sits behind a ship’s propellers to steer the vessel, the U-shaped gate rudder – essentially two separate rudders – sits astride the propeller, which, as a result, acts like a nozzle around the propeller and generates additional thrust. Both rudders can be independently controlled to provide finer steering control as well as helping vessels move sideways – called crabbing – when docking, for example.
In early trials, the gate rudder is claimed to have shown fuel-saving potential of 15% in calm waters, and as much as 30% in rough seas with improved maneuverability. It is also quieter than a traditional rudder system, reduces hull wake and can help to protect the propeller from damage – particularly beneficial in sensitive environments such as the Arctic.
Professor Mehmet Atlar, who is the project coordinator from Department of Naval Architecture, Ocean & Marine Engineering (NAOME) at Strathclyde, explained, “GATERS demonstrates significantly reduced emissions from ships particularly within coastal and port areas, challenging and even exceeding the current and future legislative requirements of the International Maritime Organization and local regulations for emissions.
“As a propulsor-based solution, the gate rudder offers a significant amount of power-saving that cannot be achieved by any other single energy-saving device currently available in the market.
“An important advantage of the gate rudder system is highly effective maneuverability within coastal and port areas as well as navigating more efficiently in waves during oceangoing operations. In addition, the gate rudder system is simple, generic and flexible, and can be installed on new-build ships or retrofitted to existing ships, as well as integrated easily with other fuel-saving and emission-reduction technologies. Based on these features, the gate rudder design presents a great prospect of replacing conventional design.”
The project’s researchers will use data gathered from the sea trials to demonstrate for the first time whether the system could be applied to an existing 90m coastal cargo ship as a retrofit and to explore its applications for other oceangoing vessel types and sizes – hence, ultimately becoming the next-generation propulsion and steering system for waterborne transport. The concept of the gate rudder has also been licensed to the world’s largest propulsion manufacturer, Wärtsilä.