ToolFusion
πŸ“‹ Case Study

MeyGen Tidal Array Mooring & Foundation Retrofit (Scotland)

Excessive seabed scour around gravity foundations causing chain uplift and tension instability

πŸ—οΈ Project Overview

First commercial-scale tidal stream array in Pentland Firth, UK

🎯 Challenge

Excessive seabed scour around gravity foundations causing chain uplift and tension instability

πŸ”§ Design Approach

Installed articulated rock armor aprons + flow-deflecting sills; upgraded mooring from 3-point catenary to 4-point semi-taut with synthetic fiber secondary lines

πŸ“ Design Diagram

Seabed (0 m RL) Foundation Scour: 3.8 m Scour: 1.2 m Articulated Rock Armor Sill (0.6 m H) 3-Point Catenary 4-Point Semi-Taut Synthetic Secondary Lines Design Metrics β€’ Scour depth: 3.8 m β†’ 1.2 m β€’ Kβ‚˜/Kβ‚š: 0.32 β†’ 0.71 β€’ U/Uκœ€ = 1.2 (tidal flow) MeyGen Tidal Array β€” Mooring & Foundation Retrofit Water Surface Tidal Flow

AI-generated project design illustration

πŸ“ Key Calculations

Scour Depth Reassessment

dβ‚› = 2.0 Γ— D Γ— (U/Uκœ€)⁰·⁢⁡
Result: 3.8 m (reduced to 1.2 m post-mitigation)
Validated via physical model testing at HR Wallingford

Mooring Stiffness Ratio

Kβ‚˜/Kβ‚š
Result: 0.32 β†’ 0.71
Improved platform station-keeping bandwidth

πŸ“Š Results

Scour stabilized within 6 months; mooring line fatigue cycles reduced by 64%; array availability increased from 71% to 89%

πŸ’‘ Lessons Learned

  • β€’Scour mitigation must be co-designed with mooring stiffness
  • β€’Synthetic secondary lines significantly reduce peak loads on primary chains
  • β€’Real-time tension monitoring enabled predictive maintenance

βœ… Key Takeaways

  • 1Scour mitigation must be co-designed with mooring stiffness
  • 2Synthetic secondary lines significantly reduce peak loads on primary chains
  • 3Real-time tension monitoring enabled predictive maintenance