The structural strengthening and refurbishment of a 4 lane highways bridge between Hamilton and Motherwell, requiring Grit Blasting, Painting and Repairs whilst under live load.
The scope of works included:
- Scaffolding installed above the River Clyde, encapsulated to contain contaminant material generated during the refurbishment process
- Grit Blasting to an SA2.5 standard using 440 tonnes of expendable abrasive
- Application of a three coat paint system, protecting the structure for 25 years using 9,300 litres of paint.
- Steelwork Repairs to strengthen the structure, which carries 4 lanes of traffic from the M74
The bridge carries 4 lanes of the A273 across the River Clyde in North Lanarkshire and is a vital link between the towns of Hamilton and Motherwell. The 4 span steel structure required Grit Blasting and the application of an industrial paint system in order to halt corrosion across its 12,664m² of steelwork.
During the Blasting phase of the contract 440 tons of expendable abrasive was used to remove the dilapidated paints and areas of corroded steel to a standard of Sa 2½. To negate the risks of flooding upon the Clyde, all abrasive was removed nightly using an industrial scale vacuum to transfer the lead contaminated abrasive into a sealed vacuum skip.
Condition led steelwork repairs were undertaken to restore areas of steelwork lost to corrosion, additional strengthening repairs were delivered to increase the capacity of the bridge given the anticipated increase in traffic on the A273 dual-carriageway due to future development in the area.
Using airless spray and traditional brush painting techniques, a three coat protective paint system was applied to the steelwork to provide corrosion protection up to a maximum life expectancy of 25 years. The bridge was finished in a bold red colour.
Learning and Innovation
During October 2005 an unprecedented amount of rainfall fell in the Glasgow area, this led to the level of the River Clyde rising by 3 metres, eventually peaking just 20cm below the bottom boards of the scaffold. Upon this project we developed systems to protect staff and secure the scaffolding against flooding in short periods; these then fed further processes designed to combat high wind speeds and manage emergency incidents.