Leading engineering specialist Spencer Group is set to begin work next month to refurbish and rebuild one of the world’s oldest suspension bridges.
A programme of essential works is planned to preserve the 200-year-old Union Chain Bridge linking England and Scotland, which was the longest wrought iron suspension bridge in the world when it opened in 1820.
The structure has a single span of 449ft (137m) over the River Tweed from Horncliffe in Northumberland to Fishwick in Berwickshire and is credited with being an influence on the design of later famous structures including 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.
Hull-based Spencer Group was appointed by Northumberland County Council to dismantle the bridge and carry out a complete refurbishment and rebuild to mark its bicentenary.
All modifications must remain in keeping with the historical significance of the original bridge - for example the works will need to restore, rather than replace, 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: '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 extensive works, including:
- removing the entire timber bridge deck and laying a new deck, using timber sustainably sourced from managed woodland
- 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
- refurbishing the towers using sandstone from the same nearby quarry as used originally to match the colour and geological characteristics, along with the same type of mortar
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.
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.'
The project is expected to take 16 months to complete, with the bridge inaccessible for around a year. During this period, drivers will be redirected 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.
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.
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.
