Spencer Group will carry out a £10.5m programme of works to preserve the 200-year-old Union Chain Bridge linking England and Scotland.
With a single span of 449 ft (137 metres), the crossing over the River Tweed between Horncliffe in Northumberland and Fishwick in Berwickshire was the longest wrought iron suspension bridge in the world when it opened in 1820. It is credited with being a catalyst for bridge innovation, influencing the design of other famous structures such as the Clifton Suspension Bridge.
The Union Chain Bridge remains the world’s oldest suspension bridge still carrying road traffic and is both a Grade I listed building in England and a Grade A listed building in Scotland.
Spencer Group has been appointed by Northumberland County Council to dismantle the bridge and carry out a complete refurbishment and rebuild to mark its bicentenary.
The specification demands that all modifications are in keeping with the historical significance of the bridge. This means restoring, rather than replacing, the existing suspension chains – every link that can be repaired will go back in its original place – and using the same type of local sandstone to repair masonry work on the bridge’s two towers.
The timber decking will be replaced, however.
Spencer will also remodel approach roads on either side to incorporate parking for tourists visiting the bridge.
Off-site project manager Joe DiMauro said: “The Union Chain Bridge was the first of its kind in the world when it was built and needs to be maintained for perpetuity because it is such an iconic structure.
“It has been in place for 200 years and this work will ensure it will remain for another 200. Our challenge is to make the bridge as good as new, while not changing its appearance and retaining the key original parts, such as the chains and links, that make it unique and of such historical importance.”
The project is expected to take 16 months to complete, with the bridge shut to traffic for around a year.
The Union Chain Bridge is only accessible to one vehicle at a time due to its restricted width and currently has a weight restriction of two tonnes. Following the restoration and rebuild, the weight restriction will be increased to three tonnes.