MMT (Sweden) has recently completed a geophysical cable route survey for the Amrumbank West offshore wind farm (OWF) project for Siem Offshore Contractors GmbH. The geophysical survey was performed by MMT for the entire inner array grid cable route.
The geophysical survey included bathymetric and side-scan sonar survey as well as sub-bottom profiling. At first a magnetometer was piggy-tailed behind the towed instruments from the MMT survey vessel IceBeam for detection of unexploded ordnance (UXO). Based on the results of this magnetic anomalies survey a ROV equipped with a gradiometer array was then used for additional target inspections. The overall length of the geophysical survey was 550 km within the OWF area of 36 km². Furthermore geotechnical site investigations have been performed to verify the findings of the geophysical survey, whereby a.o. CPT tests were undertaken.
The OWF is situated within the German Bight sector of the North Sea, north of the island of Helgoland and west of the island of Amrum. Hereby the OWF will consist out of 80 wind turbine generators and shall be interconnected by an inner array grid medium voltage (MVAC) cables with a total length of up to 86km.
[mappress]
Press release, September 14, 2012; Image: mmt