Irish Rail have confirmed the delays are now roughly 45 mins to services into and out of Heuston station.
They also said that delays are not quite as bad for Newbridge/Hazelhatch Grand Canal Dock services.
Irish Rail said a cable was stolen from its signalling system between Newbridge and Kildare. Services through the Phoenix Park tunnel are also affected.
Due to overnight vandalism of signalling equipment between Newbridge and Kildare, there will be significant delays to all services into and out of Heuston this morning. Delays of up to 60mins to all services are expected
— Iarnród Éireann (@IrishRail) October 9, 2019
Irish Rail spokesperson Jane Cregan said via Breaking News: “We have a special manual signalling system in place that takes longer for trains to get through that section of track.”
“We apologise to all of our customers that are impacted by this vandalism that happened overnight and we are working to minimise the disruption, but we expect that delays will persist through the morning peak.”
She added that the service would be completely repaired by this evening in time for the post work peak.