Client: BHP Billiton Mitsubishi Alliance (BMA)
1. Project Background
Stacker reclaimers SR1 and SR2 at Hay Point Services were due to be replaced with new machines. However, due to quality problems and delays in delivery from China, it became necessary to keep SR1 and SR2 in production for at least two more years. CMP Engineers was engaged to review the strategy for extending the life of SR1 and SR2 until the new machines were to be delivered. The strategy involved detailed inspections and repairs to any defects detected, with scheduled shutdowns for maintenance:
- Monthly: inspection and repair (~3 day shutdown)
- Every 3 Mt: inspection and repair (~7 day shutdown)
- Every 9 Mt: inspection and repair (~10 day shutdown)
Operational restrictions were also recommended, including use in stacking mode only for a interim period and a subsequent full shutdown. The alternative was significant repairs to high-risk areas to extend life for at least 2 years, possibly up to 5 years.
2. Challenge
The main challenge was to ensure the continued safe and reliable operation of ageing stacker reclaimers beyond their intended service life. This required a thorough technical review of the proposed remediation work, including:
- Structural and weld repairs
- Inspection of critical components such as the counterweight, luffing cylinders, pendants, slewing cones, and BW shaft
- Managing time and budget constraints, as the machines needed to remain in production and the financial case for the work had to be justified
Specific technical concerns included the effectiveness and longevity of weld repairs, the unknown internal condition of the counterweight, adequacy of inspection regimes for pendants, and the need for advanced NDT methods such as phased array UT.
3.Solution
CMP Engineers conducted a comprehensive review of the life extension strategy, including:
- Technical assessment of previous reports and recommendations
- Attendance at meetings and workshops to discuss value improvement and scope
- Endorsement of the proposed remediation work, with recommendations for more thorough inspection of the counterweight and consideration of alternatives to complete replacement
- On-site workshops and collaboration with the client to challenge and refine the scope, ultimately agreeing to implement the proposed strategy
- Oversight of weld repairs and structural remediation, with detailed QA documentation and adherence to BMA Hay Point specifications
- Key technical recommendations included inspecting the counterweight by cutting windows and removing concrete as needed to assess welds and steelwork, continuing with current inspection methods including phased array UT, replacing slewing cones rather than ongoing repairs, and maintaining documentation on the current condition of all major components.
4. Outcomes
Tangible Results:
- SR1 and SR2 remained in production, avoiding costly downtime and ensuring operational continuity for BMA.
- The financial case for the remediation work was analysed and shown to be justified by the client.
- Successful completion of weld repairs and structural remediation, with QA documentation and compliance with industry standards.
Intangible Results:
- Strengthened client trust through transparent communication and technical expertise.
- Enhanced reputation for CMP Engineers in delivering solutions for complex asset management challenges.
Key Learnings:
- Early engagement and thorough technical review are critical for successful life extension projects.
- Collaboration between engineering teams and clients leads to better outcomes and value improvement.
Client Feedback:
- The client agreed with the scope as proposed and endorsed by CMP Engineers, with positive feedback on the technical review and recommendations.