Spencer Bridge Engineering were appointed by Northumberland County Council to carry out a programme of essential works to preserve the 200-year-old Union Chain Bridge linking England and Scotland. The works involved fully dismantling the bridge in order to carry out a complete refurbishment of the bridge components, restoring them to their original condition. This was made possible through the use of a series of suspended underdeck access platforms, access cradles and an overhead cable crane which allowed the project team to access any area of the bridge whilst it was being dismantled.
The project involved the removal of the entire timber bridge deck using a suspended underdeck access platform and overhead cable crane, alongside the removal of all hanger rods using access cradles and an overhead cable crane.
The scope also involved the removal of all suspension chains, the refurbishment of the existing masonry towers using sandstone from the same nearby quarry, Swinton, as used originally to match the colour and geological characteristics, along with the same type of mortar. The project team were also required to restore the chains to their original strength, with links repaired instead of replaced wherever possible. Each link and chain that was able to be repaired went back in its original place.
Furthermore, the team installed new suspension chain anchorages either side of the bridge, re-installed the refurbished suspension chains and installed the brand-new hanger rods using access cradles and an overhead cable crane. Works all included a new deck using sustainably sourced timber from managed woodland, alongside completing necessary resurfacing work.
The key aim of this project was to ensure that all modifications were in keeping with the historical significance of the bridge whilst allowing it to continue to provide safe passage for bridge users in the future. This included restoring, rather than replacing, the existing suspension chains and using the same type of stone to repair masonry work on the bridge’s two towers.
A bespoke tagging and tracing system allowed the site team to tag, remove and refurbish bridge components, ensuring that they were put back in their original position on the bridge upon completion.
The approach roads from both England and Scotland were also remodelled to incorporate parking for visitors to the bridge, which remains open to both vehicles and pedestrians and continues to serve as a popular tourist attraction.
