Whorlton Suspension Bridge
VolkerLaser is currently working on behalf of VolkerStevin and Durham County Council to carry out structural rehabilitation works to the Whorlton Suspension Bridge.
What we're doing
The single span chain bridge suspension bridge was originally opened in 1831, and was only designed to carry horse and carts with coal from the Durham coal fields to the south. In 1914 the structure was assessed, and it was recommended that a 3 tonne weight limit be imposed on the bridge which has remained in place to date. It is a Grade II listed structure and a scheduled monument. It is the UK’s oldest road suspension bridge with the deck totally supported by its original iron chains.
To date, the team has received the ‘Scheduled Monument Consent’ from Historic England, approving the refurbishment works.
Working in collaboration with the client, Atkins Realis and Durham County Council, the team spent critical time understanding the terms and conditions of the consent to ensure works are being carried out in line with Historic England’s parameters, as well as continuing with design works, collaborating with the Environment Agency, and procuring the materials needed for the project start.
Thanks to these efforts, and a number of detailed works designs, the Environment Agency has granted a permit to the team for the first stage of the works, which has allowed the structure to be cleared of vegetation using specialist rope access techniques. This has allowed the specialist team to expose the supporting masonry abutments and wingwalls in order to undertake a detailed inspection. Once completed, a temporary catenary system will be installed to provide support to the existing BT cables below the deck. The installation of this system will also be undertaken utilising rope access.
The masonry towers are in process of being covered with debris netting, mitigating any potential delay by protecting against nesting birds. Once the utility diversions are completed, scaffolding will be installed, and part removal of the towers will begin.
Progress has been slowed due to the presence of bats in the Toll House, requiring sign off in the form of Bat Mitigation Licence, however the team has continued to complete set up of a secure workshop.
During the course of the project, the whole suspension and deck structure will be removed, refurbished and re-erected. Each element will be removed from site, and refurbished in this workshop. Racking and shelving are currently being installed, which will allow for the safe storage of each element.
July 2024
Following a pause in works due to the presence of a bat in the Toll House, VolkerLaser is pleased to share the required bat license has now been issued, and works are moving forward.
The team has now completed the BT cable diversion, and facilitated the fitting of additional cables as required, and has swiftly moved onto preparatory works ahead of the cable crane installation.
On both the North and South approaches, the team has completed the foundations for the cable crane, installed thrust blocks and drilled and fixed the anchors. Pre-tensioning of these anchors and installation of a waler beam for the cable crane has been completed to the South, with the installation of the cable crane now commencing on this end of the bridge.
Elsewhere, the team has also completed full removal of the parapet handrail from the bridge.
