A train derailed on Saturday evening after hitting cows near Cardross.
The train remained upright, with one wheel leaving the track, after the incident at around 6.40pm on Saturday, November 28.
The collision occurred at a low speed, with no-one injured as a result.
Train services were disrupted until the end of Saturday.
Helensburgh services terminated at Dumbarton Central and alternative transport was arranged.
Services ran as normal on Sunday.
A spokeswoman for ScotRail Alliance said measures are in place to prevent animals getting on the line, although sometimes they get through.
She added: "The collision occurred at low speed and the train remained upright on the track.
"No injuries were reported and all passengers were quickly transferred to another service and returned to Helensburgh Central.
"Our engineers were on site quickly to rerail the train and reopen the line. Services ran as normal on Sunday.
"We thank our customers for their patience and understanding as we dealt with this incident."