Today the fourth and last steel jack-up leg was settled into its jacking position on the wind turbine service vessel ‘WIND SERVER’, currently under construction at Nordic Yards in Wismar for Danish customer DBB Jack-Up Services.
During the past eight days the four huge steel pipes, which were transported to the Wismar shipyard by sea from Cuxhaven, were vertically raised and installed one by one with the aid of a giant lattice boom crane supplied specially for this project. Assistance was provided by the floating crane ‘Enak’, which from the opposite base helped to guide the legs during the erection process.
Afterwards, the land-based crane lowered and inserted the steel legs into the tube guides of the vessel. The raising and installation took two days per leg.
The four 72 meter long steel legs, each weighing 430 tons, have a diameter of 3.70 meters. Upon arrival at the work location, the ‘WIND SERVER’ jacks these stilts down onto the seafloor and raises itself above the water. The innovative jacking-system ensures a safe working position for the maintenance of offshore wind turbines in water depths of up to 45 meters.
The on-board crane has a lifting capacity to service even the large 5 to 8 MW turbines. The 80 meters long and 32 meters wide vessel will be delivered to DBB Jack-Up Services this summer.