Voith is presenting its electric Voith Schneider Propeller (eVSP) at this year’s Electric & Hybrid Marine Expo Europe. The propulsion unit offers high efficiency and greater simplicity, as the permanent-magnet synchronous motor is already integrated in the propeller. The complete omission of gears reduces noise to a minimum and frees up critical space on the ship.
Voith has a contract to deliver eight eVSPs to the Norwegian shipping company Østensjø, to provide propulsion for four offshore wind supply vessels. The four ships are being built in Spain and are already equipped for the application of CO2-neutral hydrogen technology.
The eVSPs also offer the same improved maneuvering performance as traditional VSPs – a decisive factor for use in the offshore wind industry. Comparative calculations have shown that a VSP-driven ship can maneuver safely at significantly higher wave heights, offering the operator an economic advantage. Due to the very fast and accurate thrust adjustment, the VSP can reduce the rolling motions of the ship by up to 70%, both when the ship is moving and when it is stationary at the wind turbine.
In model tests with ducted screw propellers, an average advantage of 15% for the eVSP was measured with regard to power requirements in transit. The electric version of the VSP is also characterized by lower fuel consumption in dynamic positioning because it acts very quickly against disturbing wind, wave and flow forces.
“The eVSP offers far greater flexibility in how you arrange it into the vessel because you don't have a shaft line," explained Oliver Lenz, sales application manager at Voith. "For the 1,850kW unit, the motor has 230,000Nm of torque, so we're turning quite slow, which is a benefit for operators as you have a very robust unit, with reduced noise and less vibration.
"Beyond operators, we’re also keen to meet system integrators here at the show, to make sure we are on the right path with voltage levels, and how to best offer a complete package to shipyards.”