The Challenge
Buchan Offshore Wind Farm’s ambitious floating wind development – located 75km northeast of Fraserburgh on the Aberdeenshire Coast – faced the complex challenge of determining optimal anchoring solutions for turbines ranging from 15 to 24MW capacity. As one of the first major North Sea floating offshore wind projects proposed, the stakes were exceptionally high.
The project required comprehensive anchor foundation screening and concept design activities to provide essential technical input for the Environmental Impact Assessment (EIA) and regulatory submissions. With geophysical and geotechnical site investigations completed but with the site Ground Model still under construction, Buchan needed expert consultancy support to advance critical consenting activities with limited preliminary data.
The challenge was compounded by the site’s identified variable ground conditions, which posed significant installation risks that needed careful assessment across multiple anchor technologies.
Our Solution
Drawing on our specialised floating wind expertise and familiarity with the NE8 site area from our previous ScotWind screening work, Ternan Energy deployed a comprehensive anchor assessment package:
- Foundation Screening Excellence: We conducted systematic site screening based on installation limitations, evaluating four distinct anchor solutions: driven anchor pile, suction anchor, drag anchor, and suction embedded plate anchor (SEPLA).
- Advanced Design Methodology: Our anchor concept design followed DNV standards (DNV-ST-0119, DNV-ST-0126, DNV-RP-C212, DNV-RP-E302 and DNV-RP-E303), assessing three Ultimate Limit State (ULS) load scenarios to create a design envelop of required anchor sizes.
- Integrated Risk Assessment: We provided detailed installation assessments, scour protection concept design, and identified key technical constraints to inform project planning and risk management.
The Ternan Approach
Unlike generic engineering consultancies, we approached this challenge as an anchor design expert:
Technical Excellence
Our team brought deep expertise in floating structure anchoring from both the offshore wind and oil & gas sectors. When evaluating SEPLA solutions, we could immediately assess critical factors including embedment requirements, keying behaviour, and suction bucket installation limitations to deliver realistic, implementable designs.
Site-Specific Understanding
Having previously scrutinised the NE8 area during our ScotWind site screening work, our team possessed invaluable familiarity with local conditions. This head start enabled us to rapidly identify key issues that Buchan would face with anchor design and installation at the project location.
Risk-Based Engineering
Our systematic screening approach prioritised installation limitations as the greatest risk factor, particularly for the challenging ‘hard’ soil conditions identified. We developed clear criteria based on predicted installation feasibility, providing Buchan with transparent risk assessments for different installation scenarios and enabling a zonation of the site.
Measurable Outcomes
Our anchor design services delivered critical project advancement:
- Enabled EIA Submission: The anchor sizing and installation requirements we provided formed essential inputs for Buchan’s EIA, directly supporting their offshore consents application
- De-risked Installation Planning: Our detailed assessment of installation challenges and requirements helped Buchan understand the practical constraints and opportunities across different anchor technologies
- Informed Design Selection: By evaluating multiple anchor concepts against site-specific conditions, we provided Buchan with the technical foundation needed for confident design decisions
- Regulatory Confidence: Our adherence to industry-standard methodologies and comprehensive risk assessment gave Buchan the technical assurance needed for robust regulatory submissions
The Client Perspective
Edward Unwin, Lead Offshore Engineer for Buchan, said: “The expertise provided by Ternan was valuable in helping our offshore consents application. The support in completing the anchor foundation studies ensured we could progress with confidence and deliver a robust submission at this important stage of the project.”
Ewan Fielding, Senior Geotechnical Engineer at Ternan, shared his thoughts: “Floating wind presents a diverse range of anchoring solutions, and our collaboration with Buchan enabled us to assess these options in detail. This partnership reflects our commitment to delivering practical, engineering-led solutions that help accelerate the offshore wind industry’s growth.”
Why Ternan?
As an independent, employee-owned consultancy with deep floating wind expertise, we bring a uniquely integrated approach to anchor design challenges. Our engineers aren’t simply following standard procedures – they’re experienced floating foundation specialists who understand the practical realities of North Sea installations.
Previous to this work, our support to the Buchan team with onshore cable corridor and substation location studies had already demonstrated our value-add approach, making us the obvious choice for their offshore anchoring challenges.
For renewable energy developers navigating the complexities of floating wind anchor design and consenting, our specialised services offer the ideal combination of technical expertise, regulatory knowledge, and practical installation understanding.
Looking Forward
Ternan is proud to play a part in advancing projects like Buchan that contribute to the necessary transition to clean energy. By applying our expertise at the earliest stages of development, we help our clients navigate regulatory requirements, de-risk technical challenges, and unlock opportunities that bring large-scale renewable energy projects closer to reality.
For more information about our floating wind anchor design services for your next renewable energy project, please contact Ewan Fielding, Senior Geotechnical Engineer, ewan.fielding@ternan-energy.com.