In March 2018, we agreed to invest £22m in refurbishing Edinburgh's North Bridge. The project was allocated £12m in the Capital Investment programme 2018-23. A further £10m was allocated as part of our 2018/19 budget. £14.131m of additional budget was allocated to the North Bridge Refurbishment project on 18 February 2021. This brought the budget to £36.421m which is currently included within the our Capital Investment programme.
Inspections to North Bridge carried out between 2014 and 2017 had identified many defects and potential dropped object hazards. These findings resulted in the removal of loose material and installation of netting to make the underside of the bridge safe. Structural assessments confirmed no impacts on the bridge's load carrying capacity. Since Balfour Beatty were appointed in 2018 to carry out the refurbishment works, the project team has uncovered multiple structural and safety defects, many of which were in areas not accessed for 120 years.
We are trying to keep disruption to the public to a minimum as the works take place beneath the bridge and on top of the deck. The parapets next to the footpaths are being painted and need temporary hoardings but pedestrian access is being maintained as best as possible.
The works to North Bridge include:
- Repair, grit blast and repaint all structural steelwork
- Repair, remould, grit blast and repaint the cast iron façades
- Repair the topside and underside of the bridge's reinforced concrete deck
- Install cathodic protection and structural health monitoring systems to the reinforced concrete deck
- Repair and improve the footway paving and underdrainage
- New waterproof membrane and carriageway surfacing
- Improve the structural drainage systems
- Replace the steel secondary structures over the abutments and piers with reinforced concrete slabs
- Remove all redundant utility pipes and ducts and rationalise those services that remain
- Replace the expansion joints
- Restore and repair the King's Own Scottish Borderers War Memorial located on the east plinth of the bridge's south pier
- Install permanent platforms to improve access provisions for future inspection and minor maintenance
- All temporary scaffolding required to access the structure
The benefits of refurbishing the North Bridge include:
- Restore and maintain the historic and vital link for current and future generations
- Install permanent platforms within the bridge structure to improve access provisions for future maintenance
- Community benefits which are an essential part of the project delivery, one of the main elements being education via engagement with, for example, schools and universities. There are also opportunities being provided by the contractor for placements and career support in the development of young people.
The work is now expected to be complete in 2024. This is partly due to measures being taken because of the Covid-19 pandemic and the necessary repairs revealed since gaining full access to the entire structure. The project team have been able to open up and inspect sections of the bridge not seen since construction over 120 years ago. This access has uncovered significantly more deterioration on all three spans of the bridge, leading to more extensive repairs than first anticipated.
History of the bridge
The North Bridge was constructed over the period 1894-97 by Sir William Arrol. They were also the contractor responsible for the construction of the Forth Rail Bridge.
The last major refurbishment works were undertaken in 1933. Later in the early 1990's, painting was undertaken to the decorative facings and new parapets were installed with decorative covers of spheroidal cast iron.
The bridge is category A designated, situated in the Edinburgh World Heritage Site linking the Old and New Towns.