UK: FoundOcean poised to commence work at Dudgeon OWF

This 402MW offshore wind farm will be located some 20 miles off the coast of the seaside town of Cromer in North Norfolk.

The planned operational lifetime of the wind farm is 25 years and as their name suggests, the foundations are one part of the development which are expected to remain solid throughout the project’s lifetime. Even onshore this would be some undertaking, particularly when one considers the dynamic loads produced by these incredible energy generating giants.

Now take the challenge offshore and it becomes understandable why Seaway Heavy Lifting, who were entrusted by the wind farm developers to deliver this important project, took the decision to engage a subcontractor who could be trusted to connect the two largest, and most important, components of the foundation. After all, over the next quarter of a century the foundations are required to withstand everything that the North Sea environment can throw at them, so it was vitally important that Seaway Heavy Lifting, the designers and the developers alike, were more than comfortable with the proposed material, that would be used to make that connection, and that the connection would be completed under tight quality assurance controls, safely and efficiently.

Enter FoundOcean and BASF. The duo have been hard at work since 2010, and their close collaboration has meant that FoundOcean has been able to continue its long tradition, dating back to when it was part of the Wimpey Construction Group in the 1960’s, of delivering reliable and safe solutions to the offshore construction sector.

It was one such solution that ultimately met their client’s expectations. The BASF material MasterFlow 9500. It not only addressed the longterm durability requirements of the project but also the necessary properties that are vital during the early construction phases.

The effects of early age cycling on a cementitious material have long been recognised as a precursor to an increased probability of later problems; problems which ultimately could compromise a system’s structural integrity. So ensuring a reliable, consistent and rapid strength build-up, even at freezing temperatures, is a critical aspect during the early phases of connecting the Transition Piece to the Monopile. Yet curing is only one part of the story, so too is the volume stability of the material. Again well documented research states that autogenous shrinkage is particularly prevalent in ultra-high strength materials, the very same materials which are used in such connections. The effects of this type of shrinkage is dramatic and in extreme cases can cause cracking and surface de-bonding, so the choice of MasterFlow 9500, which guards against all these phenomena, starts to become clear.

For a while connecting a Transition Piece and Monopile with grout became a difficult subject for the industry, but this has now become a subject of the past. Design changes and material improvements, along with tighter offshore QA controls, on the material’s placement, has once again restored confidence in this type of connection. Although FoundOcean and BASF have been at the forefront of restoring this confidence, through the introduction of technically superior products and services, they promise that their story will not stop there, as both parties continue their commitment to the research and development of their ideas and experience to improve construction productivity and safety.

FoundOcean expect to begin operations during spring of this year.