Case Study: Going up! Renovating a 136m high Severn Bridge maintenance lift
Every day thousands of commuters use the Severn Bridge, which crosses the River Severn and links South Wales with South West England. The bridge is Grade I listed and consists of four connected structures. It took three and a half years to build and was opened by Queen Elizabeth II in 1966. It replaced the 137-year-old Aust Ferry service, making transport to and from Wales easier, faster and safer, and its distinctive design has influenced bridge building around the world.
“This fantastic work, undertaken in a challenging environment, to refurbish and modernise our lift system has allowed my team to operate far more effectively."
Robert Penney, General Manager Specialist Bridges Group at Highways England
Of the many thousands of people safely crossing the bridge daily, few will be aware that each of the four 136 metre (445 foot) high towers of the central bridge section contains a lift within them. These narrow, windowless lifts are used by maintenance and repair teams to keep the listed bridge safe and in good condition.
Stannah installed two of the lifts in 1988 to replace the old series of Jacob ladders which were previously used by maintenance personnel to access the internal inspection platforms within the towers. Due to the challenging height and width requirements, the lifts themselves were completely bespoke, with each element custom built.
Since then, Stannah has gone on to provide service and maintenance on all four lifts on a regular basis. A number of Stannah engineers have worked on the Severn Bridge lifts throughout their careers, from apprentice level right through to the position of senior engineer.
Because replacement parts were becoming increasingly hard to source, in 2020, 32 years since the original installation project, it was time to upgrade one of the lifts for easier maintenance and improved reliability. The new project was to upgrade the control panels and re-wire the complete installation on one of the lifts.
Technically, one of the key challenges for the renovation project was one related to the extreme space restrictions within the tower structure. While the lift controller is at road level on the second floor, the drive and lift machinery had to be installed 90 metres above, at the top of the tower.
Access to the lift is through very narrow submarine hatch-style doors, which made it challenging to fit in some of the parts.
Additionally, because of their height, the towers sway in the wind, adding to the difficulties presented by the location. In fact, the winds that whistle across the estuary were one of the key engineering challenges to overcome when the bridge was originally designed.
It was also freezing work, as refurbishment had to take place on cold October and November days: “When working on this job, you are really exposed to the elements,” said Paul Lacey, Stannah’s Field Repair Manager. “Site safety was, of course, a critical concern, with our lift engineers not only having to work in confined spaces within the tower and windy conditions up at the top of the tower, but also having to access the site at road level next to a very busy thoroughfare and pedestrian walkway.”
The client for the lift refurbishment project was Lang O’Rourke and Highways England. Lang O’Rourke delivers engineering, construction and asset management solutions for organisations around the world, while Highways England is a government-owned company that maintains and improves England’s major roads.
The lift’s control panels needed to be upgraded and entirely rewired, and the two-speed control system and drive needed upgrading to a variable voltage, variable frequency system.
A new CAN X controller, which is designed to be flexible, affordable and reliable, was chosen for the update. The controller is faster to fit, with installation and commissioning time reduced through the use of pre-loomed plug and play modules.
The refurbishment involved fitting equipment unique to the project, designed by International Lift Equipment in Leicester.
The Stannah team worked in close collaboration between reliable suppliers and the client, ensuring that appropriate components were selected to keep the lift running efficiently and safely for years to come, and making sure all aspects of work on site ran smoothly
Of course, the solution was also about Stannah’s experience, flexibility and ability to deliver lift solutions in all kinds of settings and environments, with effective project management, and with safety always paramount.
Modernising the Severn Bridge lift has resulted in increased safety and reliability for the engineers and maintenance teams that use it. The other three lifts are in need of similar works, and it is expected that a rolling modernisation programme will be implemented in the near future to improve safety and reliability on all the bridge lifts.
Robert Penney, General Manager Specialist Bridges Group at Highways England, described the restoration work carried out on the bridge lift by Stannah as “fantastic”:
“Working with Stannah has proved invaluable to our operation of the M48 Severn Bridge. This fantastic work, undertaken in a challenging environment, to refurbish and modernise our lift system has allowed my team to operate far more effectively. The bridge is a listed structure and as such requires constant upkeep, but with reliable lift access we are able complete our inspections and maintenance work on time and safely so that its future is guaranteed. The Stannah team have done a great job delivering this project and I am very much looking forward to the next phase as we complete similar works on the neighbouring lift.”
As the Severn Bridge needs ongoing checking and maintenance, it was essential to enable this work to be undertaken as efficiently as possible.
The Stannah team spent just 12 weeks on the project. By delivering the renovated lift on time and budget, we were able to demonstrate our commitment to being true to our word, even for the most technically complex projects.