A total of 350 rail passengers travelling on the 10.45 a.m. Cork- Dublin train were delayed by 3½ hours yesterday when an engine broke down in Portlaoise.
A replacement engine was attached, but wasn't powerful enough to get to Dublin on schedule.
The train eventually arrived at Heuston Station at 5.20 p.m., 6½ hours after leaving Cork city. It was due to arrive in Dublin at 1.55 p.m.
A heavily pregnant woman in severe discomfort on the train was taken to the Coombe Hospital by emergency services at Heuston station.
She was attended to, but was later discharged.
The locomotive failed just before lunchtime, and a replacement engine was dispatched immediately according to an Iarnród Éireann spokesman, Mr Barry Kenny.
A full investigation is under way as to why such an unsuitable engine was attached to haul the train.
"We are investigating that," said Mr Kenny when asked by The Irish Times why a more powerful engine was not dispatched.
"Unfortunately due to resource constraints at this busy time of the week no other engine was available," he said.
"Our fleet is fully stretched at peak times, and we are under-resourced also," he added.
All passengers were offered refund vouchers to the full value of their journey under the Passengers' Charter.
Passengers travelling on to other destinations who missed connections and flights were being dealt with on a case-by-case basis by Iarnród Eireann Customer Service, said Mr Kenny.
Forms are available at Heuston station for passengers in such circumstances.
Trains following from Cork to Dublin were also affected: the 11.30 a.m. service was delayed by over two hours, and the 3.15 p.m. was late by 40 minutes, according to Iarnród.
Trains outbound from Dublin to Cork and Ennis were expected to be delayed last night as a result.