The client required a solution for attaching retrofit cathodic protection to 88 windfarm monopiles using remote intervention. Four connection points per monopile were required allowing the anode mattresses to be positioned on the seabed around each pile.
Proserv provided their HMS 3000 friction welding technology and worked together with a third party tooling supplier to provide a solution that enabled the welding of M16 carbon steel studs directly to the monopiles. These studs allowed the cables from the anode mattresses to be placed on the seabed which were directly connected to the monopile providing the required cathodic protection. Proserv’s solution allowed the welding tool control panel to be integrated with the ROV and the hydraulic feed taken directly from the ROV’s HPU.
Proserv carried out an initial weld qualification process which was approved by DNV, laying the foundations for the offshore scope to be undertaken at a later date. During offshore operations Proserv provided a HMS 3000 friction welding system consisting of a subsea weld head and subsea control system which was integrated into the ROV and subsea stud changer. All welds were completed to the client’s satisfaction with real-time data issued to the client demonstrating the project was carried out in-line with DNV approved procedures.
The provision of the HMS 3000 system and stud changer allowed for the project to be completed without the need for diver intervention. The DNV qualified weld procedure gave the client confidence that welding operations would provide the requisite cathodic protection without compromising the structural integrity of the monopiles during the welding operation. The provision of the cathodic protection has extended the working life of each monopile.
- No need for diver intervention
- Cost savings through preventative maintenance
- High quality, high integrity approved cathodic protection solution