iXSea has announced the success of the scale model Ampelmann Project, which they have sponsored. The ‘Ampelmann Project’, a research project to improve the access rate for maintenance of offshore wind turbines, is being led by the Delft University of Technology, in the Netherlands, and funded by the Dutch Government through Novem under the DEN framework. To date a scale model has been tested successfully; the next phase will involve building a full size prototype. The purpose of the Ampelmann Project is to develop a vessel-mounted transfer system that can be operated safely for more than 90% of the year. The 100MW Near Shore Wind Park off the Dutch coast has been selected as the reference site.
The result so far has been the development of a vessel-mounted Stewart platform consisting of six cylinders that can move in all degrees of freedom. By measuring the vessel motion and real-time control of the actuators in the platform, the top plate becomes stationary compared to the fixed world of the turbine. For this scale model iXSea has supplied OCTANS III, the latest release gyrocompass and vertical reference system. This is designed with a complete motion sensor that outputs true heading, roll, pitch, heave, surge and sway as well as acceleration and rate of turn. To give the system a required workability of more than 90%, it must be able to work up to and including a sea state with a significant wave height of 2.5 metres.