Balfour Beatty Regional Civil Engineering has completed restoration works to the 19th century Cragside Iron Bridge, a Grade II* listed structure situated in the National Trust owned Cragside Estate in the heart of the Northumberland countryside.
After nearly nine months of sympathetic conservation, the wrought iron bridge has been restored to its former glory and reopened to the public for the first time in 30 years.
Designed by the famous Tyneside Engineer Lord William Armstrong in 1871-72, the three span, 49 metre long, 1.5 metre wide structure was constructed across Debdon Burn, a valley running through the Grade I registered landscape of the estate. Its purpose was to provide pedestrian access from the house to the wonders of the formal garden and parkland beyond. During 1979 the bridge was declared structurally unsafe and closed to the public.
“We are delighted to have been given the opportunity to work on such a unique and historical structure,” said Managing Director (Northern), Balfour Beatty Regional Civil Engineering Neil Barnes. “By working closely with the National Trust we have successfully restored the bridge in keeping with its original design, using traditional methods of construction and minimising any impact on the listed landscape. A key factor in the successful delivery of this project was managing the interface between our operations and the many visitors to the estate.”
The £600,000 project involved strengthening and repairing the structure with two tonnes of new steel which is secured in place by extensive riveting, a traditional construction skill which has all but died out in the UK. Over 4,000 rivets were replaced across the bridge
which involved heating each rivet individually in an induction coil heater and using riveting guns.
Further strengthening works involved applying new deck bracing to the bridge, adding strength to the handrails and providing more rigidity to the bridge deck. Scaffolding was applied to the entire bridge, which allowed repairs to be carried out efficiently on different parts of the bridge at the same time. New stanchions and mesh panels have been fitted on either side of the new timber deck, completing the works.