Effective works Phase 2 - 3
2012 : week 7
The fabrication and assembly of the steel structures for the Jacket foundations are ongoing at different yards in Europe and Asia, (Belgium-Netherlands-United Kingdom-Poland-Germany-Spain-South Korea). All the jackets for phase II are constructed. The base materials for the jackets of phase III are purchased,the construction of midsections are ongoing. 22 out of the 24 jackets for phase III are under construction at the construction yard of Smulders in Hoboken, Belgium and 14 jackets of those 22 are complete. A jacket foundation is a steelstructure of tubulars designed to support the windturbines. The height of a jacket varies between 40 and 50 m.
The pile driving works started in area B of the windfarm on Wednesday 6th of April 2011. Steel piles of 40 to 50 m are driven into the seabed by a hammer installation mounted on the jack up platform Buzzard. These so called "pin-piles" are the anchors to seal the jacket foundations into the seabed. The length of the piles depends on the soil conditions. To assure the correct locations of the piles a template is lowered onto the seabed. On Sunday August the 21st all pile driving works for the project were complete which means that 196 piles were driven into the seabed in about 4,5 months.
The jacket foundation installation for the offshore transformer station, (OTS), was executed on the 15th of August 2011.
The Heavy Lift Vessel "Rambiz" installed the first jacket foundation for the windturbines in area B on Sunday 12/06/2011 and on Tuesday 14/06/2011 this foundation was grouted to the pin-piles. On 28/09/2011, so after a period of 3,5 months, all the 24 foundations of area B were successfully installed and grouted. Preparations are ongoing for the mobilisation of the Rambiz to start the foundations installation in area A beginning March 2012.
The 33 kV infield cables, making the future connection between the wind turbines were picked up in Karlskrona, Sweden, on the 23th of July 2011 and were transported to Zeebruge by the cable lay vessel CS Sovereign. The infield cable laying works started on 12/08/11 and were completed on 3/11/2011. A cable burial vessel,called the Innovator, jetted down these cables into the seabed. Two teams of special trained people did the final hang off of the cables in the WTG foundations.
The procurement of the raw materials for the 150 kV export cable is complete and the manufacturing is ongoing in Karlskrona, Sweden. This export cable is the second connection between the windfarm and the land cables. The pick-up in the factory of this cable and the transport to the offshore site is planned for mid March this year. The mobilisation of the cable lay vessel "Stemat Spirit" has started.
A dredging vessel, the "Breughel", finished the dredging in the shipping lane "Vaargeul 1", to prepare part of the trench for the 150 kV export cable, which trajectory is crossing this shipping lane.
The steelstructure of the Offshore Transformer Station is being assembled in the workyard of HSM Schiedam, Netherlands and the internal finishings are complete. The installation of the transformers is also complete. All the preparations started for the upcoming transport of the OTS to the Thorntonbank site beginning of March 2012.
REpower, Hamburg-Germany, the contractor for the wind turbines, purchased the parts of the wind turbines. Following productions are ongoing: the towers by AMBAU-Cuxhaven Germany, the blades by LM Glasfiber Holding Denmark, the generators by VEM Germany and the gearboxes by 2 constructors, WINERGY-Vörde Germany and HANSEN-Belgium. The preparations of the onshore offloading, assembling and loading site for the windturbine components of REpower in the harbour of Ostend are ongoing.
Directional drillings were executed on land for the 150 kV land cables and the cable laying onshore is complete. These cables make the connection between the offshore windfarm and the sub-station of Elia onshore. The connections of the cables into the Elia sub-station are complete. Electrical commissioning tests on the complete onshore cable connections are successfully completed.
All the permits are obtained for a horizontal directional drilling under the dunes and for the trenching works on the beach, which will be used for the onshore landing of the second export cable coming from the windfarm offshore transformer station. The site installation is ongoing and the pipes to be drilled are arriving on site.