Critical 48-volt network issue prevents power restoration as engineers work to identify source
Dublin’s Luas Green Line remains out of service for a second day following a power outage Wednesday, with no trams running between Broombridge and Brides Glen while engineers work to resolve a critical safety system fault.
Luas operator Transdev confirmed all Red Line services are operating normally, with disruption confined to the Green Line.
Engineers identified the problem within a “critical low-voltage safety” system—the 48-volt network that links substations to the central control room—rather than the overhead power supply that directly powers trams.
“It is part of the safety network that links substations to the central control room and allows power to be safely controlled and monitored across the line,” a Transdev spokesperson explained.
The safety system is designed to shut down overhead line power during emergencies. “The system is currently detecting a fault condition, and for safety reasons will not permit power to be fully restored until that condition is resolved,” the spokesperson said.
Multiple Luas technicians are working to identify the fault’s source and restore power, though Transdev has not provided an estimated timeline for service resumption.
The prolonged suspension affects thousands of daily commuters who rely on the Green Line to access Dublin city center, Dundrum shopping district, and residential areas along the route. The timing compounds disruption for Christmas shoppers and workers during the busy pre-holiday period.
During the suspension, Luas tickets are being accepted on Dublin Bus, Irish Rail services from Broombridge, DART trains, and Go Ahead bus services, providing alternative transport options for affected passengers.
Transdev apologized for the inconvenience, emphasizing that safety considerations prevent power restoration until the fault is completely resolved and verified.
The Green Line typically carries significant passenger volumes, making extended outages particularly disruptive to Dublin’s public transport network. The suspension also affects connections to mainline rail services at several interchange points.
The incident highlights the complexity of modern tram systems, where multiple safety and control networks must function correctly before passenger services can operate. While frustrating for commuters, the cautious approach ensures no services run until all safety systems are confirmed operational.
Passengers are advised to check the Luas website and app for updates before traveling and allow extra time for journeys using alternative transport options. Real-time information continues to be updated as engineers progress with fault identification and repair work.