The Wärtsilä 2-speed gear is designed to serve vessels having multiple operational modes or reduced transit speeds. These vessels like fishing vessels, rescue tugs, offshore support vessels and seismic support vessels can gain notable economic & environmental benefits.
The Wärtsilä 2-speed gear is available with a high degree of modularization in the 2 MW to 13 MW power range.
High propulsion efficiency
Certain single screw vessels, such as product tankers and fishing vessels, might have an extra class notation for redundant propulsion in case of a main engine failure. With such a class notation, the Wärtsilä 2-speed gear has a special functionality, since the shaft generator can be used as an electric motor, while the propeller runs at its lowest speed. Thanks to the choice of having two propeller speeds, the actual propulsion power needed to comply with the redundant class notation can be reduced significantly.
Reduced noise and vibration
The Wärtsilä 2-speed gear reduces noise emissions by up to 20 dB, both inside the ship and externally. This allows greater comfort for crew and passengers, while the reduced underwater radiated noise is important for fishing and seismic vessels, and is beneficial to marine life in general.
Fuel savings of up to 15% can be achieved compared to a single speed mechanical propulsion system, thanks to the key feature of the 2-speed gearbox: the option to reduce the propeller speed while the vessel speed remains constant.