Danish Kriegers Flak Offshore Wind Farm

The Project

OceanIQ^® provided route engineering services for all 72 inter array cable routes for this major offshore wind farm located 15 – 40 kilometres off the Danish coastline in the Baltic Sea. Once complete, the wind farm will be Denmark’s largest offshore wind farm with 72 turbines and a production capacity of just over 600 MW.

The project presented the particularly challenging task of locating and analysing over 6,000 boulders identified within the survey corridors. Utilising a combination of GIS software, data and high-resolution bathymetry results from route surveys along the proposed cable corridors, the team carried out a thorough analysis of the boulder sizes, weights, frequency and distribution. The intelligence was used to identify which boulders along the cable routes could be removed by Global Marine Group’s PLP240 pre-lay plough, picked up using a grab, or those which would be immovable.

This detailed analysis led to a boulder risk mitigation strategy based primarily upon avoidance of larger or heavier stones whilst retaining routes which maximised the burial potential and protection for the cables. The inter array cable routes also had to avoid the potential unexploded ordinance (pUXO) targets identified by a thorough UXO survey campaign.

Boulder density mapping and careful selection of the very largest boulders to be picked ahead of the ploughing operations led to an extremely successful first project for the PLP240.