In 2001, Network Rail, working with principal contractor Balfour Beatty, began work to put an end to the myth of the never-ending task of ‘painting the Forth Bridge’.
In the 1990s, after over a century of punishment from Scotland’s harsh elements and following years of repainting and repair works, the bridge was suffering from exposed old paint layers flaking and detaching from the steel and encouraging corrosion. But the bridge was about to undergo a pioneering process that would last nearly a decade and would see the bridge reborn.
The first stage was to assess the safest way to do the job. Every inch of the structure had to be reached in order to fully restore the Victorian icon – without disrupting the east coast mainline rail link. To overcome this challenge, impressive scaffolding systems were tailored to sections of the bridge, with new support points fabricated and welded to the structure to support this framework. Some sections even had to be suspended below the bridge.
The next stage was to use blasting techniques to reduce a section at a time back to clean steel in preparation for the bridge’s new coat of virtually impermeable paint. Before blasting took place, inspections were made of the century-old steelwork – most of which was found to be in excellent condition with only minor repairs required. Up to twenty tonnes of debris were removed per hour by industrial vacuum extractor units, while climate-controlled, optimum conditions were created to apply the new coating system, which had previously been used in the North Sea oil industry.
The painting process began with a coat of special, anti-corrosion primer before high-build epoxy glass-flake epoxy paint was applied, by hand, to each of the 6.5 million rivets and all of the leading edges of surfaces before the same specialist coating could be applied to the whole structure. Once the correct thickness was achieved, the famous topcoat could be applied. Known as ‘Forth Bridge Red’, the final layer of paint was specifically created to emulate the original red oxide colouration the bridge had when first opened in 1890.
The restoration operation was completed in December 2011, marking the first time the entire structure had been repainted in its history. And, with an expected lifetime of 20-25 years, the myth surrounding the continual repainting the Forth Bridge has become another part of this iconic structure’s history.