An electric train has been tested on the main line between Edinburgh and Glasgow for the first time.
The ScotRail Alliance train operator said it marks a step forward for the major project to electrify the line, which has faced several delays.
The electric train, which has still to be fitted with interiors, travelled between Edinburgh and Linlithgow at 2am on Wednesday, the first time an electric train has travelled on any section of the route.
Full testing of the new trains is due to start when safety checks on the remainder of the route are complete.
Ian McConnell, ScotRail Alliance programmes and transformation director, said: "Yesterday's trial was a hugely important step towards completing the electrification of the line between Edinburgh and Glasgow.
"Having a train run on the route is one of the final phases of the electrification process.
"That it has gone so well tells us that we are almost ready to begin the next stage - which is to start fully testing the new trains themselves."
He said the new trains would enable "cleaner, greener travel".
The Edinburgh Glasgow Improvement Programme (EGIP) was originally costed at £742 million, with the first electric services expected to come on to the route in 2016, a deadline that was pushed back until July 2017, then December 2017.
Last month, First Minister Nicola Sturgeon confirmed there was a further delay and told MSPs it is due to Network Rail being "behind" on the electrification of the route, and also in slippage by train manufacturer Hitachi in delivering the new electric trains.
Hitachi Rail Europe programme manager Andy Radford said: "It's positive to see that progress is being made on Edinburgh to Glasgow electrification.
"We're hopeful that we'll be given permission to start full testing soon so we can guarantee the trains can run for passengers safely.
"We've now got trains at our factory in Newton Aycliffe ready to travel to Scotland as soon as they can run on new electric power line."
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