Project Summary
A Fixed Offshore Wind Developer contracted a vessel for monopile installation, but excessive crane block motions prevented lifting tool insertion for upending of monopiles, causing delays in installation and dispute. Tadek conducted independent due diligence, hydrodynamic modelling, and operability assessment against contractual limits.
The Challenge
Monopile installation could not commence due to unanticipated operational limitations during lifting tool engagement.
- Excessive crane block motions prevented lifting tool insertion
- Upending and piling operations were consequently delayed
- No specific engineering analysis had been undertaken for tool insertion
- Tool insertion was not identified as the most restrictive weather condition
- Missed weather windows were disputed under Nominal Operability Limits and off-hire provisions
Tadek’s Role
Tadek provided independent engineering verification and technical investigation support:
- Reviewed contractor documentation and operability definitions
- Developed a validated hydrodynamic vessel model
- Analysed vessel and crane block motions
- Benchmarked in-field performance against contractual limits
- Delivered formal investigation findings with detailed recommendations to optimise the installation process and ensure compliance with engineering and operational requirements
Our Approach
Our approach combined contractual review with objective hydrodynamic analysis.
- Modelled vessel RAOs, damping and motion response
- Assessed all monopile installation stages
- Identified the lowest limiting weather condition
- Compared engineered limits with operational behaviour
- Produced evidence-based technical conclusions
Outcomes
Our analysis produced evidence-based technical conclusions:
- Lifting tool insertion process was identified as the operation with the lowest limiting weather conditions of the monopile installation process
- Engineering gaps were confirmed within contractor documentation
- In field vessel performance shown to diverge from Nominal Operability Limits
- Evidence-based findings provided to support contractual review
- Recommendations developed to improve future vessel contracting and operability definition
