The Scotsman reports that work has started on a new quarter-mile section of the line from Leadhills into Wanlockhead, where it is hoped trains will run from 2020.

The move comes 20 years after original plans to extend the half-mile-long track across the border from South Lanarkshire to Dumfries and Galloway. The volunteers involved hope it will be boost tourism in 1,531 ft-high Wanlockhead, which boasts a lead mining museum and Europe’s second oldest subscription library - after Leadhills - which were founded for miners.

The tiny trains on the 2ft-wide tracks - half standard gauge - terminate at Glengonnar Halt, outside the village. However, they were called on to replace buses for a week last summer when the parallel road between Leadhills and Wanlockhead was closed for resurfacing, saving villagers a 45-mile detour.

The extension breakthrough came when agreement was reached with the landowner for the work to proceed. Alan Mackie, chairman of the Lowthers Railway Society, which operates the line, said: “Thanks to an agreement we concluded with Buccleuch Estates last year, we’ve now able to access the track bed and are digging test pits to find out where the track drains need to be dug.

“We’re following the track bed of the former Caledonian Railway line, which linked Elvanfoot with Leadhills and Wanlockhead and closed in 1938.

“We’re using our railway’s digger, which we brought up by rail from our base at Leadhills, to dig the pits.

“We’ve found the original ballast still intact below the surface of the ground.”

Mr Mackie hoped the track bed would be cleared and the site of the new station levelled by next August. Trains are expected to start running in 2020 - 82 years after the last one operated.

Mr Mackie said: “Once we can run right through to Wanlockhead, it will boost passenger numbers as well as being good for tourism and attractions such as the Museum of Lead Mining and one of the world’s oldest lending libraries in the village.

“There’s a great deal of work to be done, but we’re confident our experience running trains on the line for the last 30 years will allow us to complete the extension on time.”