Leading Guidelines for Design of Suction Caisson Foundations

The Carbon Trust has published the Offshore Wind Accelerator (OWA) Suction Installed Caisson Foundation Design Guidelines, to increase industry confidence in the use of suction caissons.

This important document brings together the latest understanding and research to provide clarity and guidance for engineers looking to design suction caissons for foundations in offshore wind. The guidelines provide an overview of the critical factors to consider when incorporating these designs and give practical support to engineers in order to manage the design process efficiently and cost-effectively.

Suction installed caissons have seen increased acceptance in the offshore wind industry due to their potential for low-noise and quick installation, and suitability to certain challenging soil conditions, which enables them to compete on a commercial basis with traditional monopile and jacket designs.

The OWA has been instrumental in the commercialization of suction installed caissons with Universal Foundation’s Monobucket and SPT Offshore’s Suction Bucket Jacket, originally selected as winners of the foundation design competition back in 2013. Subsequent OWA projects then demonstrated their viability and application offshore, as suitable foundations for met masts and a full-scale turbine. Now, suction installed caissons can be seen supporting the latest generation of 8MW turbines at Vattenfall’s European Offshore Deployment Centre in Scotland and Ørsted’s Borkum Riffgrund 2 in Germany.

The guidelines were written on behalf of the OWA by an expert author team, led by geotechnical consultancy Cathie Associates and consisting of subject matter experts from the University of Oxford and SPT Offshore. The participation of OWA partners ensured the guidelines matched expectations of developers, and are applicable to offshore wind projects in different geographies.

The Guidelines are available for download here.

Elson Martins, Manager of the OWA Foundations research area, the Carbon Trust, commented:
“We are excited to continue to support innovation in the offshore wind sector. The publication of these guidelines represents the culmination of 18 months of hard work and collaboration and an important landmark for this foundation design concept as it continues to drive down the costs of offshore wind.”

Jamie Irvine, Senior Engineer from Cathie Associates commented:
“The guidelines provide the industry with a long sought after methodology that gives greater clarity to designers and developers on the key issues concerning the design of suction caissons. These guidelines are for the geotechnical design of suction caissons and present the current state of knowledge and good industry practice for SICF design. As lead authors, we hope this guidance enhances confidence in the use of suction caissons in the offshore wind industry and facilitates design and review process.”