Irish Rail said services were returning to normal Friday evening after severe disruption was caused by a broken down train at Glasnevin Junction.
The company said the train had been moved and normal services were resuming to and from Maynooth, Longford and Sligo subject to delays.
Trains on all these routes, along with Hazelhatch, were all impacted by the incident.
The disruption began during rush hour when the 16.35 train between the M3 Parkway and Docklands experienced mechanical failure at Glasnevin.
Irish Rail sent a team to site but there were knock-on delays to a large number of trains for the evening.
Dart services were running as normal.
A delayed 17.15 Longford train was eventually freed to travel through an alternative route while a Sligo train, which had been stranded on the line, returned to Connolly and also took a different line out of Dublin.
The service failures occurred at one of the busiest commuter times of the week.
