The Patea Rail Bridge Project involved a full refurbishment of the steel structure to extend the life of the rail bridge.
Specifically the project involved:
- The design and construction of an access and containment system;
- Surface preparation, including an abrasive blast of the steel to remove corrosion, salts and the lead based paint, followed by a water wash to ensure a clean substrate was achieved;
- Application of the new coating via an airless spray unit and by hand in the areas that were difficult to access; and
- Bird proofing and minor structural repairs
The job brought a number of challenges to the project team, particularly around the management of the old lead based coating system and the need to maintain full operability of the rail corridor. A complex access and containment system was engineered and built by TBS to fit around the bridge structure to contain the lead based paint, enable the rail corridor to remain operational and protect workers from train movements.
Train clearance inside the containment structure was at an absolute minimum so it had to be built to withstand potential damage from contact with any loose chains or couplings on the trains. There were no unexpected delays or closures of the bridge and workers could safely continue work throughout the shift without disruption.
A strict lead management procedure was also developed to ensure that employees received minimal exposure to the lead dust and it was not released to the Patea River below. The design and condition of the bridge structure meant that there were many corroded areas that were difficult to access. Significant time and a commitment to quality control was invested in ensuring that all areas of corrosion were fully removed before repainting commenced.