Proserv Offshore, a global provider of subsea maintenance, abandonment and decommissioning solutions and services to the offshore energy industry, has recently been awarded a substantial contract with DONG Energy to supply and operate their innovative wind generator pile cleaning solution at DONG’s Walney 1 Windfarm, located in the Irish Sea.
The specialized Marine Growth Removal (MGR) solution was initially developed and manufactured by Proserv Offshore’s Aberdeen facility for a major installation contractor in the North Sea. They required a solution to speed up the pile cleaning process and avoid possible costly maintenance work in the future.
Surface cleanliness of the pile is critical for effective grouting and all loose debris and marine growth needs to be removed quickly and effectively to prevent any costly grout removal after installation. Pile cleaning using a diving team is time consuming and costly so it was necessary to develop a solution that was fast, effective, reliable and with ease of deployment and recovery. Furthermore, it was important that the solution require minimal human intervention and could also be adjustable for a range of different pile diameters.
DONG Energy’s Installation Manager, Peter Buhl, said; “The cleaning of the mono piles prior to grouting is an important process in the build cycle. By using this tool, we eliminate any uncertainty of the pile condition prior to the grouting process taking place.”
The solution is deployed from a support vessel and placed directly upon the open pile. The surface of the pile is then cleaned by lowering a sub frame down the pile utilizing high pressure water jets mounted on a track. The jets rotate 360 degrees to clean 450mm paths around the pile to a depth of 8m. The whole cleaning process is completed within 90 minutes whereas it may take a diving team 30 hours to achieve the same result.