Roodee Viaduct, located just outside Chester, measures in at 108ft long and consists of three spans across the Special Area of Conservation (SAC) designated River Dee.
The scope of works included:
- 3 level Scaffolding to the underside of the structure, piers and 5 lattice girders
- Grit Blasting to an SA2.5 standard to provide a key for the application of a 3 coat protective paint system.
- Design, Fabrication and Installation of a new public walkway and access staircase
- Steelwork Strengthening to the superstructure with Concrete infill to the supporting piers
The bridge carries two ballasted tracks and also has a pedestrian walkway running alongside it. Taziker Industrial (TI) were tasked with carrying out the strengthening and refurbishment of the existing bridge structure, as well as the replacement of the walkway. We engaged with numerous stakeholders as part of this project, as well as tackling extremely restricted access to the work site.
In collaboration with our Consulting Engineers, Hyder Consulting, we used specialist software to produce a model of the walkway, which allowed us to produce accurate, detailed fabrications drawings. These drawings meant that our specialist engineering division were able to accurately fabricate the walkway extremely quickly, whilst also minimising waste.
The location of the viaduct meant that TI had a number of key stakeholders that needed to be engaged and brought along as the project developed. Its proximity to Chester Racecourse, as well as a public footpath that runs alongside it meant that negotiating access was complicated. In addition, the River Dee is designated as an SAC due to the types of vegetation and fish that inhabit it and part of the project was funded by Chester Council. TI were praised for the proactive way in which we dealt with multiple stakeholders and addressed their concerns.
Learning and Innovation
Access to the work site was the biggest challenge we faced on this project. We were not permitted to use Chester Racecourse as an access point, so could only gain access via the public footpath and through the original brickwork arches. This restriction meant that we couldn’t use wagons or traditional mobile cranes to transport materials to site. Instead, we utilised a special compact mobile crane that was able to offload material from the wagon and transport it along the footpath and through the brick arch to the work area. We also worked closely with our Consulting Engineers to design the stairs and walkway so it could be transported in small sections and installed using a mini ‘Spider Crane’ that was small enough to manoeuvre into position.