UXO detection for Borwin III Project

G-tec was employed on the BorWin3 framework Project to carry out a geophysical and UXO survey along the proposed cable route from the intertidal area to the offshore Borkum Island (Germany).

The aim of the seabed survey was to identify and map potential hazardous obstructions prior to the trenching and cable laying works, the data allows the Client to adapt the cable-route if necessary to avoid any anomalies found.

The objectives for G-tec were:

• To provide seabed bathymetry, seafloor imagery, sub-surface geology and magnetic measurements within the installation and associated anchor corridors.
• To locate ferro-metallic objects and identify those anomalies which model as potential UXO.
•  To determine the horizontal and vertical variations in seabed sediments.
• To confirm the location and condition of existing seabed infrastructure.

Several different techniques have been deployed on the project; magnetometry, side scan sonar, multibeam echosounder and sub-bottom profiler. Due to the location of the site it was determined that a close grid was best suited for the planned survey. Utilising G-tec’s bespoke "MagWing" - a dual vertical gradiometer frame, the survey planning and results were optimized and all the milestones achieved.

The resultant data provides G-tec’s Client all the necessary information to characterize the seabed in terms of possible hazardous obstructions and seabed profiling in order to adapt the cable-route and secure the future trenching works.