Project Summary
Tadek led the structural and lifting design for subsea concrete block installation forming part of a major UK marine infrastructure development. Specialist lifting frames and transport engineering were developed to ensure precise placement, controlled subsea release, and fully DNV-compliant offshore execution.
The Challenge
Installation required precision handling of six concrete block designs across three assembled rows beneath the seabed.
- Four bespoke lifting frames required for varying block geometries
- Integrated Torquer lifting system required subsea release verification
- Strict survey tolerances for sequential block placement
- Interface coordination between lifting, grouting and rock bag backfill
- Monitoring of subsea connection detachment during set-down
Tadek’s Role
Tadek acted as design authority for lifting, rigging and transport engineering.
- Full structural design and fabrication drawings for four lifting frames
- Design reports, method statements and operational storyboards
- Rigging and lifting plans compliant with DNV-ST-N001
- Seafastening design for offshore transportation
- Engineering assurance across fabrication and mobilisation phases
Our Approach
Our approach prioritised structural integrity, operational clarity and offshore practicality.
- Defined design specifications and lifting load paths at concept stage
- Integrated survey and installation tolerances into frame design
- Developed offshore-ready procedures with site team input
- Coordinated contractor interfaces and compliance reviews
- Provided continuous engineering support during execution
Outcomes
The works were executed safely and in accordance with programme requirements.
- Four certified lifting frames designed, fabricated and load-tested
- DNV-compliant documentation and risk assessments delivered
- Efficient offshore and onshore coordination achieved
- Rapid mobilisation within suitable weather windows
- 41 of 67 blocks successfully installed as programme progresses
