Rail commuters faced massive delays this morning after a signal fault affected a significant number of services.
Irish Rail attributed the delays to a "major signal fault" on Twitter and said services "into and out of Heuston are impacted".
However, speaking on RTE Radio One's Morning Ireland, Irish Rail spokesperson Jane Cregan said the fault is "impacting everything from Dublin to Cork and also Dublin to Athlone". She said they are not providing alternative transport, adding; "There are thousands and thousands and thousands of people impacted."
Engineers succeeded in putting a manual signalling system in place shortly before 8am.
This meant that Intercity services including Galway/Westport services into and out of Heuston began operating again at 8am.
However, delays of up to 90 minutes remain to Intercity services today.
Due to a major signal fault. There are currently no services operating into and out of Heuston. This includes Newbridge/Hazelhatch to Grand Canal Dock services. DART, Commuter and Intercity services into and out of Connolly are not impacted. Update to follow— Iarnród Éireann (@IrishRail) May 28, 2019
Ms Cregan said this morning there was no alternative transport in place for customers as Irish Rail would not be able to source enough buses to cater for everyone.
"We're hoping to have it rectified as soon as possible," she said.
"Everything from Dublin to Cork to Limerick... a train may have got as far as Charleville, the Waterford route may get as far as Kilkenny.
"It's the whole signalling system. In reality there is nothing moving in or out of Heuston."
She continued; "With the number of people impacted we're not in a position to provide buses. We're advising customers to seek alternatives... for those who have not yet got on the train.
"We will have to wait until the signal fault is recitifed. We have engineers working on the fault, but yes, there is a significant delay to customers en route to Heuston at present.
"The majority of people have not yet left the station. Because the system is down, there is nothing we can do.
"We couldn't get buses, they wouldn't have been sufficient."
At Heuston Station passengers were stranded and waiting for information.
Some were travelling for work reasons, while others were tourists on day trips.
"We were due to go to Cork for a meeting on the 7am train, and we only found out there was a problem when we got here," said Aisling Toms, who was with a group from Musgrave wholesalers.
"We actually heard it on the radio before anyone in the station told us. The notice boards were still reading 'on time' at that stage," said Niall Mullaly.
"We're trying to find a way around it, but we may just have to go back to work here in Dublin," Aisling added.
Another group of workers who were hoping to get to Cork for a meeting were waiting patiently at the main concourse.
"We work with Marks & Spencer and were due to go to Cork for three days with work," said Aisling Ryan.
"We travel by train sporadically but this hasn't happened before.
"There was no sign of any difficulty when we arrived, and we only found out at 7am when we were due to board the train.
"Our tickets are not transferable to a bus, so we don't know what will happen now. We will wait and see," she added.
The Railtours tour operator was also affected by the delays, and staff at its stand were fielding questions from customers who had booked tours with them, most of them tourists from abroad.
"We had hoped to go the the Cliffs of Moher and Bunratty, but it looks like that won't happen now," said Robyn Koch from Wisconsin in the United States.
"The guy at the stand is apologising and offering us a refund or a chance to travel tomorrow, we don't know what we'll do yet," she added.
"Maybe it was meant to be, maybe we'll have a great day in Dublin. Who knows?," she said with a smile.
Sally Frees from Canada was also booked on a Railtours trip, and said because she was on an overnight tour the company was organising a bus to transport the passengers.
"I had hope that the situation would be resolved, it has to be safety first. If I was stranded I'm sure there's lots to do in Dublin anyway," she said.