Proserv is a global leader in subsea applications, providing flexible and reactive engineering solutions, from the installation and maintenance of the structure through to decommissioning at the end of field life. Our areas of expertise include decommissioning contractors and engineers, abandonment services, and subsea and marine technology.

Subsea and marine technology for offshore wind turbines

The generation of electricity through offshore wind power has developed rapidly over the last few years. As the renewable energy sector continues to grow, more offshore-based wind turbines are being installed to meet the growing demands for wind energy.

Owner operators and installation companies are therefore continuing to look at ways of improving efficiencies and reducing maintenance lifecycle costs using innovative solutions and technologies.

Marine growth removal (MGR)

When installing a wind turbine, any delay between mono pile installation, transition piece placement and grouting operations can be costly as marine growth and other surface debris can often quickly appear on the mono pile surface. As surface cleanliness of the pile is critical for effective grouting, all loose debris and marine growth needs to be removed quickly and effectively to prevent any costly grout removal after installation.

Proserv has designed, developed, manufactured and tested a MGR tool. Already considered standard equipment by major industry-leading contractors within the European offshore renewable energy sector, the MGR tool produces excellent results every time.

Hydraulically controlled cleaning tool for offshore turbines

The MGR tool is a specialised solution deployed from a support vessel and located directly on the open pile. The surface of the pile is then prepared by lowering a hydraulically controlled cleaning sub-frame down the pile. Utilising high-pressure water jets mounted on a track, a full 360° by a 450mm-wide path is cleaned around the pile.

Once the carriage has completed a full rotation around the track, the support fabrication is lowered to the next position and the surface preparation process is repeated in the opposite direction.

This process continues until all the transition area has been prepared to the required standard. Once complete, the rotations are ceased and the lowered fabrication is pulled back up the pile to its secured transport position within the top located fixture. The whole tool can then be lifted and placed back on to the deck of the support vessel ready for the next pile deployment.

MGR tool benefits

Using the MGR tool, a pile of 4.7m in diameter can be completely prepared to a depth of 8m in less than 2hr. Considering it would take a diving team over 30hr to achieve the same result, this is a significant time saving for our customers.

The tool’s functions, including a circular track speed, jet rotation and jet pressure, are fully adjustable and controlled by the operator onboard the deployment vessel. The hydraulic power, high-pressure water and electrical power to the observation camera system are supplied via an umbilical. All support equipment, including the high-pressure, high-volume jetting pump, is located on the support vessel.