North Bridge Refurbishment
Project value: £17.5 million
Sector: Infrastructure
Local spend within 40 miles: 100%
Local labour within 40 miles: 82%
Spend with SME subcontractors: 81%
Waste diverted from landfill: 98%
Local jobs created: 22
Project procured via: Scape Civil Engineering framework
"As part of our broader plans to create a people-focused Capital under the long-term City Centre Transformation programme, the road running over the bridge will eventually benefit from active travel improvements, connecting to our growing network of walking and cycling-friendly routes."
Councillor Lesley Macinnes
Transport and Environment Convener | The City of Edinburgh Council
The City of Edinburgh Council need a full refurbishment to secure one of Scotland’s most iconic structures, which is rapidly deteriorating.
After years of heavy use, exposure to the elements and limited maintenance due to poor access, the historic, Grade A-listed North Bridge is beginning to crumble.
Identifying a growing risk to both the railway underneath and passing pedestrians, the council opted to refurbish the three-arch bridge and install a permanent platform to improve the ease of future maintenance.
The project, awarded to Balfour Beatty by The City of Edinburgh Council, via the SCAPE Civil Engineering framework aims to repair, conserve and replace the historic structures supporting this landmark.
The iconic North Bridge is a three-span structure passing directly over Waverley Station and linking the Old and New Towns, which are both UNESCO World Heritage Sites.
In its current form, the bridge was constructed circa 1895, and although remedial maintenance work has been completed over the years, this has been difficult due to access limitations.
To minimise the risk of falling debris, the first critical task will be to place crash decks under each of the bridge’s three spans, preventing anything from falling to the ground during the complex inspection and repair work that will take place.
The restoration and upgrades will be phased, and include:
- Structural steelwork repair
- Strengthening and maintenance works
- Grit blasting and repainting of the structural steelwork
- Repairs to the cast iron facades and the underside of the bridge’s concrete deck
- Replacement of expansion joints and joints at road level
- Installation of permanent platforms for future maintenance access
During enabling works, the latest technology has been used to maximise efficiency working closely with the council, an effective BIM Execution Plan (BEP) has been created. The existing structure has been 3D laser scanned, using drones, and modelled. This has informed decisions on buildability and clash detection, and the model will also help the council with planning and undertaking future maintenance on the bridge.
The focus on health and safety is of utmost importance, with ongoing toolbox talks, mobile apps and training to ensure the site team remain vigilant.
As with any project, there are many stakeholders that need to be kept updated, including the council, Historic Scotland, Network Rail and local businesses - regular communications are being circulated to keep all parties informed of the progress.
The council wants to extend the life of this historic bridge and create a structure that over the next 25 years will not require any further works, other than inspection and minor maintenance.
A key focus of the project is to remove the risk of any further objects falling from the underside of the bridge onto the railway and rail station below.
Additionally, the installation of the permanent maintenance access platforms will provide access for undertaking thorough inspection and maintenance – something that has not been possible until now.
Community benefits 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 Balfour Beatty on placements and career support in the development of young people.
The bridge sits above a live railway station and railway lines, as well as Market Street, which carries both vehicles and pedestrians. The logistics of maintaining access to a complex live site such as this needs careful consideration and management throughout.
An access scaffold needs to be suspended from the existing bridge to enable works to be completed. This is a delicate balance of providing enough scaffold to deliver the works without putting too much strain on the existing structure.
Network Rail are kindly providing space for the works to be carried out as well allocating areas for the materials to be stored. The works are taking place above the live railway, which is particularly difficult as the works has to be carried out over 75 Nr 2hr night time possessions of the railway.
When completing the permanent works, the challenge will be weaving steelwork and other materials into and out of position through the temporary access scaffold and existing steel bridge – not an easy task, as there are 6,300 existing steel members in the bridge and approximately 250km of scaffold tubes, with 60,000 scaffold clips and 15,000 13ft scaffold boards.
100%
local spend within 40 miles
81%
SME spend
22
local jobs created