July 16, 2010
First wind turbine installers with Voith Schneider propulsion
Voith Turbo has released some further information on the Voith Schneider Propeller (VSP) systems in the two enhanced GustoMSC 9000C design wind turbine installation vessels that the Lamprell Energy Ltd. shipyard in Dubai is building for Fred Olsen Windcarrier AS.
Equipped with four jack-up legs, the 131.m x 39 m vessels will each have three Voith Schneider cycloidal propellers aft and and three tunnel thrusters forward and will have a transit speed of 12 knots.
According to Voith Turbo, the vessels will have an input power of 11.4 MW, 5 300 tons maximum load, an operating platform covering some 3 200 square meters and an installation crane capable of lifting loads weighing up to 800 tons up to a height of 24 meters.
High performance, maneuverability and reliability are the key requirements for the propulsion system. The three VSP ensure propulsion and accurate positioning.
For the jack-up process, the vessels have to hold their position with extreme precision. This is where the advantages of the VSP in direct combination with the dynamic positioning system come into special effect. It only takes three seconds for the drives to reverse. This prevents the ship from making leeway, which is normally inevitable due to the swell of the sea. The moment when the vessel is lifted from the water is particularly critical. During this transitional phase of lifting, the VSP delivers significantly better thrust than other propulsion concepts, says Voith Turbo.
The VSP also allow a simple hull shape. The ships can thus be built with an hydrodynamically efficient design that has a positive impact on consumption figures and emissions -- something that Voith demonstrated by model testing.
The vessels also have intelligent Voith Roll Stabilization (VRS). If weather conditions are difficult - a frequent occurrence in offshore wind parks - the VSP reduces the rolling motions of the vessel.