FoundOcean has started work on a groundbreaking offshore wind farm off the northeast coast of the UK. The wind farm is using the latest design in Transition Pieces, adopting a bolted flange connection for all of the 73 turbine foundations. As well as the bolted flange, the Transition Pieces are also being secured using a high strength grout which is capable of being mixed and pumped using a high-output recirculating jet mixer (RJM). When complete, the wind farm will produce 219MW, enough to power 170,000 homes.
The award follows a very successful onshore trial to demonstrate that FoundOcean could exploit its 25m³/hr output RJM to mix Parex 100N grout. In achieving this, FoundOcean has taken another significant step towards industrialising the grouting process, using high-strength materials which are normally associated with the much slower batch mixing process.
The primary focus for FoundOcean has been, and still is, to deliver the right grout materials to customers using the most efficient grouting system. To date, the market has demanded blended aggregate materials, with only Ormonde, Thornton Bank and Borkum West II being the exceptions by using bulk Portland cement. Up until now, cementitious-based blended aggregate materials must be transported and mixed in batches to prevent segregation and to ensure the quality of the final material. What Parex has achieved in the formulation and preparation of their 100N Grout material has meant that FoundOcean can now offer a high-strength solution which can be transported and delivered in bulk without risk of separation. The benefit of this is that for each offshore trip FoundOcean can transport more material and grout more foundations quicker than ever before.
FoundOcean engineering director Damien Murphy explains why this is such a radical step for the renewables sector: "The non-separating Parex material enables FoundOcean to transport it in silos and therefore we can use our silo-fed RJM mixer. This will reduce cement resupply runs and nearly quadruple current high-strength grout output rates, contributing to a significant reduction in the time it takes to grout a foundation."