Sif Group in the city of Roermond is working hard on the production of 43 steel foundation piles for the Eneco Luchterduinen Wind Farm.
Ultimately, these piles will be installed 23 kilometres off the coast between Noordwijk and Zandvoort. What makes these foundation piles special is the fact that the wind turbines will be mounted directly on top of them, representing an innovative new technique which has only previously been applied in a relatively small number of cases.
A flange is the flat edge at the end of a pipe. In view of the direct impact of the pile driver on the foundation pile, the 30 centimetre wide flange connection presented a challenge during the design process, because this is the part to which the wind turbine towers are connected by means of nuts and bolts. Eventually, the team decided to make the outer edge of the flange horizontal for driving purposes with a slight downward slant towards the inside. This ensures that the surface to which the bolts will be attached will remain intact during the piling process.
The production of the piles at Sif Group started in November 2013. The flanges were made in Spain and will be welded onto the piles in Roermond, after which the completed units will be installed at sea in the second half of this year by main contractor Van Oord. Eneco Luchterduinen will be operational by the end of 2015, at which time it will generate green power for approximately 15,000 households. The wind farm is a joint operation between the Japanese company Mitsubishi Corporation and Eneco Group.
Press release, February 21, 2014; Image: eneco