English Heritage's Iron Bridge conservation project will return the bridge to its original red-brown colour.

The Iron Bridge is the world's first bridge made of cast iron and is considered to be a symbol of the Industrial Revolution.

The new research into the original paint shades was undertaken as part of Project Iron Bridge, a £3.6 million conservation programme to restore the bridge for future generations.

Historic paint researchers studied previously inaccessible parts of the ironwork and examined parts which have become detached from the bridge over the past 200 years.

English Heritage's Senior Property Curator, Dr Heather Sebire, said:

'Uncovering the original colour of the Iron Bridge has been a fascinating mix of both archive research work and detailed forensic investigation. We had already found some clues in the archives but the decider was the results of our analysis of the historic paint, revealing a red-brown coating beneath centuries of historic dust and paintwork. That's when we knew we had found the answer to the key question about the original colour of the Iron Bridge.

'While the bridge is covered in scaffolding, visitors will be able to see it up close and personal via our public walkway, and watch our team of painters transform this revolutionary structure to its original red-brown. And of course, when the scaffolding comes down at the end of the year, we'll reveal one of the most important bridges in the world, in all its glory.'

Clues from an 18th century painting

The red-brown colour can be seen in William Williams' 1780 painting Cast Iron Bridge near Coalbrookdale. This is one of the earliest depictions of the bridge and was commissioned by Abraham Darby III, who oversaw the building of the pioneering structure.

The findings were examined by a panel of historians and representatives from heritage bodies. They were also presented to the Ironbridge Gorge World Heritage Site Steering Group.

About the Iron Bridge

Erected in 1779 across the River Severn in Shropshire, the Iron Bridge was the first single span arch bridge in the world to be made of cast iron. It was a turning point in the history of British engineering.

Recent surveys revealed that the bridge was under threat from cracking due to stresses in the ironwork dating from the original construction, ground movement over the centuries, and an earthquake in the 19th century.

Last year as part of the launch of Project Iron Bridge, English Heritage raised £47,545 in its first crowdfunding campaign. A €1 million donation from the Hermann Reemtsma Foundation also provided significant support for the project.

Find out more about Project Iron Bridge.

For more from English Heritage, follow us on Facebook, Twitter and Instagram.