Video report by ITV News North of England reporter Amy Welch
The oldest railway viaduct in the world is undergoing a £3.8m restoration ahead of its 200th birthday in Merseyside.
Over the next four months, the overhaul from Network Rail will ensure the structure remains safe and reliable.
Senior Programme Manager Mark Evans said: “I think it’s a testament to our forefathers and engineers of the past that when they built these structures they really didn’t know what they were going to be facing, but it really has weathered well considering its age.
“This restoration will not only make sure it looks good but will also secure passengers and freight trains for the future too.”
A team of 25 engineers are working on the project. They will be repairing the brickwork, removing weeds and plants, and installing metalwork to protect the structure.
Alongside this, they will also be using paint and historical materials to make sure the repairs are in line with its original design.
Heritage Consultant Lorna Goring said: “It’s really important that the materials and the techniques used in the repairs are appropriate for the physical properties of the structure."
More modern technology is also being used to help identify the areas where repairs are needed, 3D scanning has been used to create a computer model of the viaduct.
The viaduct is over 160 metres long, and was given Grade 1 listed status in 1966.
Local historian Dr Barry Pemberton thinks that’s not enough, and is calling for it to be given world heritage status.
He said: “There are two engineering firsts here that both changed the world.
"The Sankey Canal began the canal revolution, and the Liverpool-Manchester railway line started the railway revolution.
“Those two revolutions only exist in one place. We’re actually standing in a place of history.”
The viaduct is currently 193 years old, but with its 200th birthday in 2030 approaching these repairs will make sure it can still operate for decades to come.