GATE RUDDER™ by Wärtsilä reduces a vessel’s fuel consumption by replacing the drag of a traditional rudder system with a thrust-enhanced arrangement. The arrangement also provides excellent manoeuvring capabilities and improves the noise and vibration signature. Placing the high-lift rudder foils on either side of the propeller enables turning at higher speeds and faster course changes.
Wärtsilä’s collaborative partnership with Kuribayashi Steamship Co., Ltd. will accelerate the deployment of gate rudder technology across many vessel classes. The combination of Wärtsilä’s propulsion and machinery integration expertise and the Japanese patent holder’s gate rudder technology and know-how will enable ship owners throughout the marine sector to benefit from the technology concept.
GATE RUDDER™ by Wärtsilä is an innovative energy-saving and manoeuvring device with a unique design formed of two foils on either side of the propeller. During transits, the resulting thrust performance benefits from the hydrodynamic effects of the propeller and steering system. Unlike a traditional rudder arrangement, during transits the gate rudder foils can rotate their angular position, changing the hydrodynamic load on both the propeller and the foils. This is proven to have a positive effect on efficiency, particularly during varying sea conditions, weather or currents. For manoeuvring purposes, the function of the foils changes to a thrust-directing device.
The resulting reduction in fuel consumption depends on the vessel type, its operational profile and on the reference propeller and rudder. The main application for gate rudder technology so far are single screw vessels. Vessels with a gate rudder technology installed, have reported fuel savings as high as 20%.
Gate rudder technology also improves manoeuvring performance by making it possible to turn with higher turning speeds. Using the crabbing mode, significant thrust can be generated sideways. This benefits the crabbing or pivoting mode, depending on the combined use with a bow tunnel thruster.