Spencer Group’s bridge division has completed the latest instalment of maintenance works at the Grade I-listed Menai Suspension Bridge ahead of the crossing’s bicentenary in 2026.
Workers replaced and painted 168 of the 208 wire rope hangers on the bridge to restore the full structural integrity of the structure, which is an essential road traffic link between mainland Wales and the Isle of Anglesey.
After completing earlier projects, including the replacement of footpath panels and the installation of emergency failsafes on the 417m-long bridge, Spencer Bridge Engineering’s team began the hanger replacement project in autumn 2023 and recently installed the final hanger.
To respect the heritage and historic features of the bridge, the team worked closely with suppliers throughout a rigorous period of development and testing to design the specially fabricated hangers and sockets.
A significant achievement
The hangers, which range in length from less than 1m to over 14m, were fabricated to a stringent specification, with an incredibly narrow length tolerance by specialist Swiss steel manufacturer Fatzer.
The hangers were installed when the bridge was reconstructed in 1938.
To undertake the works, Spencer’s bridges team also designed bespoke equipment, including a detensioning rig and pin pusher to safely remove the existing hangers while protecting the surrounding bridge structure.
Spencer said the completion of the hanger replacement programme to schedule marks a significant engineering achievement for the team given the complexity of the task and the speed with which it needed to be designed, procurement and supply chain challenges, and adverse weather conditions over the works period.
A successful project
The bridge was shut without prior notice on 21 October 2022. A statement from the Welsh government at the time said it was closed for essential maintenance work following safety recommendations from structural engineers.
The bridge was initially shut completely in both directions but was soon reopened to foot passengers. On February 2023, the bridge was reopened to traffic in both directions, subject to a 7.5t weight restriction.
The weight restriction has been temporarily lifted to allow all vehicles to use the bridge during winter and will be reinstated when restoration works restart after February 2025.
Spencer Bridge Engineering’s project manager, Tom Inglis, said: “The project posed a number of significant challenges, including working in a harsh environment with strong winds and wet weather, but we have a large and diverse skillset which enables us to draw on past experiences to develop solutions.
“One of the factors which made this project so successful was the close relationships we have developed over a number of years with the client, UK Highways A55 Limited, and our suppliers. Those relationships were especially important to deliver this challenging project on time.”
