Rotech Subsea Completes North Sea Sand-Wave Clearance Job

Rotech Subsea has competed a sand-wave clearance for Van Oord at the Norther offshore wind farm in the Belgian North Sea.

Aberdeen-based subsea excavation pioneer Rotech deployed its TRS2 controlled flow excavation tool to carry out the scope of work.

The TRS2 result was that instead of the two campaigns originally programmed to clear the route, the entire scope was completed in a single campaign.

“The capabilities of the TRS2’s controlled flow technology and its ability to pre-sweep a wide corridor extremely quickly and effectively resulted in increased productivity and a reduction on the project’s total costs,” said Stephen Cochrane, Rotech Subsea director. “Sand-waves up to 2.5m in height were excavated successfully in water depths of up to 35 meters. The project was a huge success, allowing for the Norther IAC to be accessed for burial. Soil conditions were described as Very Dense Silty Sand to Clay, and the TRS2 achieved an excellent average excavation rate of 3m/min.”

With the sand-wave scope successfully completed ahead of schedule, Rotech’s recently developed RSG cable grab tool has been deployed on a cable recovery scope until February 2020.