Growth in the number of passengers using the Borders Railway line will be held back by the building of a series of new bridges, campaigners fear.
The Campaign for Borders Rail (CBR) said at least eight more bridges over the largely single line between Newcraighall and Tweedbank are due to follow a new A7 bridge at Falahill, near Heriot. Their construction could prevent the line being double tracked in the future, campaigners say.
The group condemned the move as short-sighted, arguing that twin tracks would be required in the future if the £353 million Edinburgh-Tweedbank railway is as successful as previous line re-openings, such as Airdrie-Bathgate, Stirling-Alloa and Hamilton-Larkhall.
The bridges include replacements for demolished bridges and former level crossings removed after the former Waverley line closed in 1969, but will leave room for only one track underneath.
The total length of double track on the 30-mile line has already been reduced by one-third from 15.5 miles to 9.5 miles. The CBR said later modifications to the bridges to enable double tracking would cost up to ten times as much as their construction.
Chairman Simon Walton said: “Significant lengths of the Borders Railway will be constructed as single track. Loops are being designed to allow trains to pass in either direction.
“While there is sufficient provision for the proposed level of service, additional double track provision will be needed in future if demand levels increase, and especially if ambitions are realised for eventual extension to Hawick and Carlisle.
“What may appear to be a minor issue now – a bridge that precludes a section of double track installation – does have major significance for the future of the line.
“Is the most long-sighted policy to build rail infrastructure as cheaply as possible now, at the risk of very expensive enhancement or extension at a later date?”
Colin Howden, director of transport campaigners Transform Scotland, said: “It is remarkably short-sighted of the Scottish Government to deliver this project in such a way as to make future capacity increases more expensive.
“All recent rail re-openings have massively exceeded patronage expectations and there is every reason to expect the Borders Railway will also need increased capacity in future years.”
However, Network Rail, which is building the line and will maintain it, said the plans were “perfectly adequate” for trains to run on time.
A spokeswoman for the Scottish Government’s Transport Scotland agency, which is in charge of the project, said: “An alternative solution at Falahill has now been given planning permission and Network Rail will fully consider the viability of the alternative design before raising the matter with Transport Scotland.”