WSP, with the client’s representatives, visited prospective suppliers, to complete vendor audits prior to appointing suppliers and then progressing to inspection activities during the manufacturing stages.
Our audit findings were shared with EPC contractors and their suppliers to best influence quality processes during manufacture. As Hydro Tasmania were not able to travel out of Australia during the unprecedented COVID pandemic, WSP provided vital support for a wide range of activities and key FAT inspections both remotely and in person.
As the distributors and runners are manufactured in various locations in Europe.
Our scope covers:
- Inspections of each runner at raw material stage (NDT) through to checks at final machining (homology, NDT) and shop balancing.
Distributor fabrication and trial assembly inspections.
- Inspection of guide, thrust and turbine bearings (work ongoing), shafts.
- Inspections during the fabrication of generator stator frames in India and Austria. As work was carried out under a Framework contract with multiple work packages issued, we were additionally required to undertake essential visits driven by inspection findings.
Our approach
We recognise the unique design of each power station. Our role was to assist Hydro Tasmania with the Quality process, inspection planning and manufacturing phases, including a review of processes and inspection and test plans (ITPs). Hydro Tasmania benefited from our considerable global supply chain experience and our strategy to influence and improve quality performance and control during manufacture. WSP’s goal was to provide project continuity of resources, add value, work with main contractors, whilst respecting our third-party status to achieve a common end goal.
Outcomes
The most notable technical challenge was the dynamic balancing of each Francis runner in the workshop prior to delivery. These units were 5, 7, and 10 Tonne runners which presented a number of technical challenges. With our support, all the units were successfully balanced.
Significant issues were found during our inspection of the Wilmot fabricated operating ring, resulting in the item being remade which has successfully been installed and commissioned, meeting specification requirements and resulting in significant cost savings.
During 2015 inspection of the cast hub for the Cluny Kaplan turbine, significant surface defects were observed during machining (>1000). WSP assisted with the NDE technique to complete the inspection and provided close supervision of the excavations and subsequent weld repairs. For Francis runner casting upgrade inspections, we identified defects missed by the sub-contractors. Subsequently, our experience and due diligence ensured the runners were repaired in accordance with specification and objective evidence was provide to the client in WSP’s detailed Quality Reports.
As protective coating process issues, coating system issues, damage to guide vane housing bearings and head covers were identified; our interventions have reduced process pitfalls and ensured coating longevity.
We witnessed the trial assemblies of all distributors to ensure high accuracy for line boring and to avoid potential issues on site. As a result, detrimental issues were highlighted and rectified at source within Europe, significantly reducing the impact of project delays, and the avoidance of high site costs.
During the COVID pandemic, we were able to help expedite bearing manufacture in Europe, by remote inspection and the mobilisation of site visits (ensuring strict COVID working protocols were strictly followed).
For the Trevallyn runner, the wrong weld consumable had been used during casting upgrade. We were able to support the process providing vital information during the FAT and beyond.
WSP continues to receive exceptional feedback from Hydro Tasmania confirming that our involvement significantly helps during the installation and commissioning.
Continuity has ensured that historical pitfalls are avoided and helped the sub-contractor chain understand the requirements of the client requirements, particularly in instances where a sub-contractor does not have a ‘first-hand’ understanding of site conditions.
