RAILTRACK HAS put a 20mph (32km/h) speed limit on part of the East Coast Main Line in Scotland after fears of subsidence caused by abandoned mine workings.
The 1. 5km section of the line is at Dolphingstone in East Lothian.
An assessment of the area is under way to help engineers decide what remedial works will be needed.
A Railtrack spokesman described the speed limit as 'precautionary' but said the track had was being monitored round the clock. On-board equipment is also being used on trains.
Engineering options are likely to include grouting, installation of a geotextile blanket, track bed replacement or use of a reinforced concrete slab. All will involve temporarily diverting the railway.
A similar problem in 1999 prompted Railtrack to spend £6M relaying the track bed at Wallyford, 1km from Dolphingstone (GE June 2000).