Services were not running on a large part of the line.
Luas red line services are running with delays this afternoon after a tram broke down.
The tram broke down at the Blackhorse stop, and forced services to run a limited service.
There was no service between the Kingswood and Heuston stops, and trams were only running between Tallaght/Saggart and Kingswood and Heuston and The Point.
Services have now resumed after the tram was moved, but there are delays of up to 20 minutes on the service.
Luas says: "Red line services currently running with delays due to a broken down tram at Blackhorse.
"Failed tram is on the move so passengers please be advised trams will now run the line as normal with appx 20 min delays.
"Tickets are still valid on Dublin Bus. Apologies for the inconvenience."