Borders Railway overcomes 'cluster' of problems
ScotRail has said the Borders Railway is on track to "exceed expectations" on passenger numbers despite a "cluster" of problems over the summer months.
It comes after campaigner Bill Jamieson catalogued a string of cancellations due to a range of issues.
He highlighted problems with class 158 trains being used on the route which were "prone to engine overheating".
ScotRail said annual leave, sickness absence, train issues and a tree on the line had all affected services.
Mr Jamieson studied performance on the route between Edinburgh and Tweedbank between the end of March and middle of August.
He found 74 days with cancellations across a period of 143 days.
'Acts of God'
ScotRail's own figures show less than half of services - 43.4% - have reached Tweedbank on time.
"Obviously nobody can be blamed for incidents which might be termed 'Acts of God'," said Mr Jamieson.
"And a lot of the crew shortage issues were probably as a result of the conductors' dispute and should not or may not recur."
However, he said there were other factors which could have played a part, which included the use of class 158 trains.
"Class 158s seem to be prone to engine overheating whenever the air temperature approaches something that might be considered normal for summer," he said.
"This doesn't necessarily result in complete failure, but it can mean that a train with only one engine functioning will crawl up to Falahill and lose a few minutes in the process."
He said a newly opened railway in Germany or Switzerland would have been provided with new rolling stock.
"The other significant cause of delays is conflicts with other trains at Abbeyhill Junction, just to the east of Waverley Station, and at Portobello Junction, where the Borders Railway joins the East Coast Main Line," he said.
"This tends to be the basic source of late running but is exacerbated by the shortened sections of double track on the Borders Railway, which spread any initial delays to trains running in the opposite direction.
"In the worst cases, the delays bounce around the passing loops until the only way to sort things out is by a train cancellation, either of a complete service or sometimes by missing out most intermediate stops."
A ScotRail spokeswoman said there had been a "cluster" of problems in July and August which had had an effect on services.
"As with other parts of the railway network, the Borders line is subject to occasional technical faults," she said.
"As always, we do everything we can to keep customers moving when things go wrong.
"We are on track to exceed expectations as far as passenger numbers are concerned and we're working to ensure that reliability matches the demand for services on this new line."