It’s more than a bridge. It’s a link between Edinburgh’s Old and New Towns; it’s a vital transport link; it’s a structure with engineering history attached; and it’s one of the city’s most popular viewpoints.
If you hadn’t already guessed, it’s North Bridge – and it’s finally nearing the end of a years-long and eagerly awaited refurbishment that should see it not only looking brand new, but also fit for another century of use.
By the time it is finished next year, North Bridge will have taken longer to refurbish than it did to build. But that shouldn’t be altogether surprising, given the evolution of a complex project designed to protect a key part of the city’s built history and culture.
In terms of time and costs, the original plan for £22million over two years had to be radically revised as the scale of the problems facing the refurbishment were revealed by detailed inspection, layer by layer. Factor in the discovery of asbestos in the structure, the global pandemic and its attendant restrictions, and you begin to see the issues faced. Come next year, it will be seven years and £86million to see the project through to a successful conclusion.
And now the city is looking forward to finally unveiling the fruits of a gargantuan task carried out by the international infrastructure group Balfour Beatty for the Council. If you pause at the use of “gargantuan” here’s a few interesting statistics that may convince you:
- The bridge is 160m long, almost 25m wide, and is made up of three spans each of more than 50m
- A colossal, enveloping scaffold was built for the bridge, requiring 300,000m of scaffolding tubes
- The cast iron façade and its decoration has been stripped off and sent to specialist off-site blacksmiths to be sensitively checked and restored
- On average each day, 100 operatives have been onsite
- Within each span, an average of 500-600 sites requiring strengthening and repair were identified and dealt with
- 80,000 new, heritage-friendly, bolts have been installed in the structure
- New road surfacing and footpaths are being laid
- A new permanent access platform will be created under the bridge to allow better and easier future maintenance
North Bridge, which has the highest A-listing in terms of its architectural importance, has an important place in bridge-building history, built in the Victorian era as it was by Sir William Arrol, who also built the Forth Bridge and Tower Bridge in London. It took from 1894-1897, and the foundation stone was laid by then Lord Provost Andrew McDonald in 1896. The ornamentation was designed by the city architect of the time, Robert Morham.
Stephen Knox, Services Manager for the City of Edinburgh Council, explained that keeping the road open or partially open while the work had been ongoing had been one of the challenges, and added:
“There’s actually only a very small amount of work being done on the top of the bridge – the vast majority of the work is being done underneath.
“There’s a vast array of complex steelwork, that’s all been surveyed, assessed and repaired, often requiring new bespoke pieces to be designed and fabricated, and that’s all to facilitate the bridge being suitable for service for many years to come.
“Most of the engineering is hidden, covered in this beautiful cast iron façade which doesn’t play a structural part – but it’s been a very important part of the refurbishment.”
Rory McFadden, Project Director at Balfour Beatty added: “Grit blasting, repairing and repainting all structural steelwork and entirely replacing large sections of the bridge’s concrete deck are just some of the works that were needed to restore the North Bridge.
“Specialist welding of the cast iron façade components continues at a workshop offsite. At the workshop the components are dismantled, blast cleaned, tested for defects and fractures, after which components are very carefully welded back together. Waterproofing has been improved, and we have improved the ducting for power and technologies.
“Hundreds of paving slabs and kerbs that were damaged have been replaced appropriately to the heritage of the bridge. The lighting columns have been repaired where necessary and repainted.
“It has been an absolutely mammoth task, but one we have been delighted to be involved with given the importance of the bridge – not just in terms of its amazing history but also because it is such an important feature of the life of the city.”