Norfolk Marine Ltd has installed its Tyre Filled Net (TFN) Scour Remediation System at E.ON’s Scroby Sands Offshore Wind Farm.
The system has been installed on 5 monopile foundations at the site to provide protection against further scouring of the seabed at the foundation bases.
After extensive testing and development, including scale modelling at HR Wallingford’s new Fast Flow Facility, the TFN system was installed in late 2015.
The TFN System captures and maintains natural seabed sediments, thus reinstating the seabed with naturally occurring materials. This prevents further scouring around base of subsea structures and protects cables at the critical interface between trench and J tube. For new build sites, the system can be installed after monopile and cable installation has been completed and thus reduce upfront investment in scour protection systems, Norfolk Marine explained.
HR Wallingford concluded: “Our analysis of the short term impacts showed that the nets were effective in preventing and reducing scour around monopile foundations.”
E.ON Operations & Maintenance Manager, Steve Johnson, commented: “The TFN System developed by Norfolk Marine Ltd gives a cost effective alternative to rock dumping or sand/stone filled geotextile bags. The TFNs can be easily removed for cable maintenance, and can be reinstalled, without the need for expensive dredging.”