Although the project had faced a critical preparation and mobilisation schedule on Wednesday 20 April 2011, the newly built 5000 mT Heavy Lift Vessel (HLV) Oleg Strashnov sailed on schedule for its maiden trip to the Sheringham Shoal Offshore Wind Farm location.
The vessel was loaded with 4 220 Ton, 25-meter-high transition pieces, each with a 5-meter diameter, that were installed on top of the existing foundation piles in water depths ranging from 15 to 22 meters. These transition pieces form the basis for the windmills that will later be placed on top of the structures by other contractors.
The HLV Oleg Strashnov successfully completed the installation of the four transition pieces as scheduled, and returned to port to collect another load of transition pieces and foundation piles. During the campaign, the HLV will shuttle between Vlissingen, the Netherlands and the Field, installing 4 piles and 4 transition pieces at a time. In total, SHL is to install 71 transition pieces and 66 mono piles.
The mono piles, each with a diameter of approximately 5 meters, weigh between 375 and 531 ton and are up to 61 meters long. Recently, the Oleg Strashnov has successfully installed the two topsides that collect the power from all windmills in the field and export it to shore for distribution to households. The installation will span the summer season of 2011.
Source: shl, May 17, 2011