A £3.4m investment is being made to repair the iconic Glenfinnan viaduct in Scotland, regularly used by “The Jacobite” trains and world-famous for its appearance in four Harry Potter films.

The repairs are part of Network Rail’s ongoing maintenance programme to ensure the viaduct that was built in 1901 is fit for the future.

At 1,000 feet long and 100 feet above the River Finnan on the West Highland Line it is the longest concrete viaduct in Scotland.

Engineers from Network Rail and its principal contractor AmcoGiffen will initially assess the condition and strength of the viaduct, before carrying out remediation work to protect it from water erosion. They will also repair the concrete and improve the track bed to keep the ballast in place.

When constructed around 1900, the Glenfinnan Viaduct took four years to build at a cost of £18,904. It is Grade A-listed, which means that Network Rail must ensure that its work does not affect its appearance, including not cleaning off marks left by water drainage. The work is expected to take just under a year to complete.

There will be no disruption to rail services during the work and no change to the viaduct’s appearance. Throughout the work, Network Rail will keep residents and businesses informed about the work and its progress.

The viaduct is an iconic landmark which attracts visitors from across the world, so we’ve worked hard to develop a solution which will help preserve the structure, respect its historic significance while minimising the visual impact of our work.

Laura Craig, scheme project manager, Network Rail

We are privileged to contribute to the preservation of this cherished landmark and will work closely with Network Rail to protect the heritage of the viaduct and surrounding area while repairing its structural integrity for generations to come.

Stephen Campbell, operations director, AmcoGiffen

ScotRail journeys on the West Highland Line, taking in the iconic Glenfinnan viaduct, are incredibly popular and it is fantastic to see this work being carried out by our colleagues at Network Rail Scotland.

There will be no disruption to any of our services during the work, and we look forward to giving as many people as possible the chance to experience the journey in the coming weeks and months.

Mark Ilderton, service delivery director, ScotRail

The scenic rail journey has become a hugely popular route between Fort William and Mallaig. It is very popular with Harry Potter fans and attracts visitors from across the world. In addition, it also provides a valued service to those living and working in the communities it passes through, so it is essential that repair works and works to safeguard the route’s future is carried out.

Councillor Ken Gowans, chair of The Highland Council’s economy and infrastructure committee