Five Ashtech ProFlex 500 GNSS receivers are helping guide the operations of the self-propelled offshore wind turbine installation vessel Bard Wind Lift I during construction of the first commercial wind farm in the German North Sea. The GNSS receivers are used for the jackup's every manoeuvre, including precisely positioning the vessel, assisting it to accurately jack itself up from the seabed on 71m long legs, and install foundation piles.
Denmark's Eiva provided the positioning solution for Bard, the new wind farm's German designer, builder and operator. Eiva created and installed the special positioning system employing five of the Ashtech receivers integrated to a survey grade gyrocompass and a motion sensor. Two of the receivers are located on two of the jackup's legs, another antenna is located on the 500t crane boom at the stern of the vessel, and a fourth is on the supply barge lying alongside to assist the crane operator during lifting operations.
Lasers measure the distances between antennas and distance to the deck during pile driving. All sensors are interfaced to Eiva's NaviPac software to manage placement of the piles. A fifth ProFlex 500, placed on a separate platform in the Bard ƶijϻ 1 operational area, acts as a reference station to provide accuracies described as ‘centimeter-level'. OE