A two stage trial of the Scour Prevention Mats was undertaken at E.On’s Scroby Sands Offshore Wind Farm in 2012 and 2013 to demonstrate the Scour Prevention Mats offshore.
Stage one of the trial involved the placement of six Scour Prevention Mats on the open seabed followed by the removal of one mat. This phase of the trial focussed on developing and proving installation and removal methods of the mats. This phase also gave evidence of the seabed stabilisation ability of the Scour Prevention Mats where there was migration of sandwaves across the site.
The second stage of the trial remediated existing scour at a wind turbine monopile. The scour pit around the turbine was infilled with tyre-filled nets and Scour Prevention Mats were laid on top. Results from multibeam echosounder surveys undertaken before and soon after mat installation are shown to the right, illustrating the increased seabed level around the pile. Pre-existing secondary scour caused by rock dumping used as previous scour protection is still seen: the trial’s aim was to remediate scour immediately around the pile.
The trial successfully demonstrated that the mats stabilise the seabed onto which they are placed and encourage seabourne sediment back into previously existing scour pits.
The trials were supported by the Technology Strategy Board.