Iarnród Éireann has advised travellers that their 6pm service from Dublin to Cork has been cancelled.
In a message posted on its website the company said the train has been cancelled due "to operational problems associated with drivers not covering absences".
Poeple wishing to travel on the Cork train are advised to get the 6:30pm train from Heuston to Tralee and change at Mallow.
The earlier 1:30pm service was also cancelled however travellers were accommodated on the 2:30pm train.