For Santos’ Ningaloo Vision FPSO Special Survey 8 dry dock, we avoided major delays by replacing a prescriptive repair scope with an engineering-led, risk-based approach. By reshaping inspection and steel renewal strategy before the vessel reached the yard, we cut steel renewals by 45%, reduced repair complexity, and took hull steelwork off the critical path – saving significant time, cost, and operational disruption.
The challenge
Santos faced a dry dock campaign where hull structural repairs were trending far larger than expected. Early inspections showed a high number of anomalies and, under default IACS scope, this translated into approximately 248 tonnes of steel renewals and around 1,900 repair worksheets – putting SS8 schedule certainty at risk for Ningaloo Vision.
Key challenges included:
- More defects than anticipated, driving up renewal quantities.
- Default Class requirements implying large crop-and-renew volumes irrespective of risk.
- Hull steel repairs moving onto the dry dock critical path, threatening return-to-field and production restart.
- High uncertainty in tonnage, manhours and emergent work.
- Risk of extended time off station with significant commercial impact.
Our solution
We partnered with Santos to reshape the entire repair strategy using targeted inspections, risk-based engineering and live scope control – without compromising Class or safety.
Our work included:
- Optimised inspection planning by starting inspections early, targeting high-risk areas, and ensuring all details needed for repair scoping and Class acceptance were captured before arrival in the yard.
- Risk-based engineering using stress and corrosion assessments plus FMECA to justify alternatives to like-for-like crop-and-renew, enabling cold repairs and fitness-for-service where appropriate.
- Establishing the standard IACS baseline scope, then iteratively refining it as verified inspection data and engineering calculations became available.
- On-site shipyard support, including rapid TQ close-out, emergent repair scoping, and live steelweight tracking using our TruHull digital twin to maintain transparency and control.
The outcome
Our approach delivered a safer, faster and more predictable SS8 campaign for Ningaloo Vision, with hull steelwork removed from the critical path.
Key outcomes delivered:
- 45% reduction in steel renewals, from approximately 248 tonnes down to 135 tonnes.
- Repair worksheets reduced from around 1,900 to approximately 1,000, significantly reducing congestion and coordination effort.
- Estimated 30-40% reduction in manhours, materials, cost and schedule driven by reduced steel volume and fewer hot-work repairs.
- No compromise to Class or certification, supported by in depth understanding of defect risk, and monitoring of known defects, such as mandated ROV inspections of ballast tanks.
- Reduced time off station, supporting an earlier return-to-field and production restart.