Tyre Mattress Scour Protection Trial Phase 1

Scour Protection System trials being undertaken of Lowestoft at Scroby Sands Offshore Wind Farm.

Early in 2012, Norfolk Marine Limited was tasked with the development of commercial installation methodology for the latest innovation in scour prevention systems being developed. Off-site trials and planning were completed and by August of 2012 on site works to install the tyre mattress sections began.    

Phase 1 of the trials involved installing six tyre mattress sections on the open seabed within E.ON’s Scroby Sands Offshore Wind farm development. The tyre mattress sections were lowered to the seedbed from the installation vessel and secured in position by the dive team. The mattress sections, each measuring 5 meters by 10 meters were joined together on the seabed to simulate scour protection over a cable run.

Once in position the tyre mattress sections were monitored for a period of six weeks to establish their performance and stability on the seabed. On completion of the monitoring period, 1 tyre mattress section was recovered from the seabed to complete the trial and prove the whole process from installation to removal.

During the six week monitoring period the mattress section were exposed to the severe weather conditions encountered at the site.

The trial showed that when placed on the seabed the tyre mattress sections quickly filled with sand carried by the tide and were not subject to secondary scour which is the down fall of most current scour protection systems. The tyre mattress sections once filled with sand proved impossible to move and remained stable as sand waves moved across the seabed.