Train services between Edinburgh Waverley and Helensburgh are expected to be disrupted until midnight due to overhead wire problems.
The line issue between Dalmuir and Dumbarton Central is having a knock-on effect on the service to the east of the country.
Scotrail said the Edinburgh Waverley - Helensburgh service may be revised at short notice, and will terminate at Hyndland rather than Helensburgh. Those who need to travel from Hyndland to Helensburgh can use a First Glasgow bus for the remainder of the journey by showing their train tickets.
The 6.23pm Edinburgh Waverley to Helensburgh Central train and the 6.37pm Edinburgh Waverley to Garscadden service were both cancelled due to the fault. This forced passengers for stops including Livingston and Bathgate to find alternative transport. Network Rail is working to resolve the problem with the overhead wire.