Leading engineering specialist Spencer Group will begin work next month to refurbish and rebuild one of the world’s oldest suspension bridges.
Spencer Group will carry out a programme of essential works to preserve the 200-year-old Union Chain Bridge linking England and Scotland.
With a single span of 449ft (137m), the historic crossing over the River Tweed from Horncliffe in Northumberland to 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 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.
A key element of the project will be to ensure all modifications are in keeping with the historical significance of the bridge. This will include 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.
Spencer Group Managing Director Gary Thornton said:
“We’re delighted and honoured to have been selected to carry out such an important project. It’s both a pleasure and a privilege to have been given the responsibility to preserve this precious structure for future generations.
“We will be bringing many years of accumulated knowledge and expertise to this project, from working on iconic bridges across the UK and Europe.”
The project will involve:
- Removing the entire timber bridge deck using a suspended underdeck access platform and overhead cable hoist.
- Removing all hanger rods using access cradles and an overhead cable crane.
- Removing all the suspension chains.
- Refurbishing 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.
- Restoring the chains to their original strength, with links repaired instead of replaced wherever possible. Every link and chain that can be repaired will go back in its original place.
- Installing new suspension chain anchorages either side of the bridge.
- Re-installing the refurbished suspension chains.
- Installing the new hanger rods using cradles and an overhead cable crane.
- Laying the new deck, using timber sustainably sourced from managed woodland, and completing resurfacing work.
Spencer Group will also remodel the English and Scottish approach roads to incorporate parking for visitors to the bridge, which is accessible to both vehicles and pedestrians and is a popular tourist attraction.
The project is expected to take 16 months to complete, with the bridge inaccessible for around a year. During this period, drivers will be re-directed by a short diversion.
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.
Joe DiMauro, Off-site Project Manager for Spencer Group, 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.”
Amid growing concerns about the condition of the famous structure, a funding bid was submitted to the National Lottery Heritage Fund (NLHF) by Northumberland County Council, Scottish Borders Council, Museums Northumberland and community group Friends of the Union Chain Bridge.
Northumberland County Councillor, Glen Sanderson, Cabinet Member for Environment and Local Services, said:
“This is a truly great project, which must be the largest and most ambitious cross-council joint endeavour ever.”
Councillor Gordon Edgar, Scottish Borders Council’s Executive Member for Roads and Infrastructure, said:
“This is another hugely positive step forward for such an important project.
“We’re now looking forward to work starting as the next chapter of Union Chain Bridge’s unique history gets underway.”
The Union Chain Bridge in numbers
- 200 years old.
- 449ft (137m) single span.
- 444 chain rods.
- 31 tonnes of wrought iron chains.
- 800 cast iron chain pins.
- 170 wrought iron hangers.