Safeguarding the Forth Bridge

Our teams and contractor, Balfour Beatty, are currently refurbishing and repainting the North Queensferry approach span of the bridge.

We began work in February 2021 by building a bespoke encapsulated zone on the 130-year-old structure and are due to finish in the coming months.

The fully enclosed scaffolding net allowed safe access to the bridge while preventing any disruption to rail services and to minimise noise for the local community.

We grit blasted the old layers of lead-based-paint from the structure and inspected the bridge for damage.

Our teams then repaired any damage and applied a new glass flake epoxy paint using the iconic Forth Bridge red colour. Now completed, this job will not have to be carried out for another 30 years thanks to the new paint system.

The Forth Bridge has been an important part of Scotland’s Railway for more than a century. Our work on the approach spans is vital to ensure we continue to maintain a safe and reliable railway.

Working on a structure of this scale is a major challenge for our engineering teams but the main challenge is preserving this iconic piece of civil engineering:

• it was the first major structure in Britain to be made of steel and its construction resulted in a continuous East Coast railway route from London to Aberdeen
• it has three double cantilevers with two 1,700ft suspended spans between them, at the time the longest bridge spans in the world
• as required by the Admiralty, the rail level is 150ft (46m) above high water
• each of the towers has four steel tubes 12ft (3.7m) in diameter and reaches to a height of 361ft (110m) above high water
• their foundations extend 89ft below this into the riverbed, making the total height from foundations to the top of the towers 137m
• the total length of the bridge, including its approach viaducts is 2,467m; the main structure itself measures 1,630m portal to portal.

We announced a major refurbishment project on the Forth Bridge in 2001. Over the following 10 years, we covered the sections of the bridge with significant scaffold access to prepare it for sandblasting and repainting.

Just like our most recent project, we removed the old paint, carried out steelwork maintenance and then applied the new paint. We applied the new paint by airless spray and by hand to an area of 230,000m².

The techniques and paint we used during this refurbishment meant the bridge didn’t require a new paint until now. This finally put an end to the myth that painting the Forth Bridge is a never-ending task.