The Rail Procurement Agency (RPA) last night insisted the Luas network remained totally safe. It was responding to the latest expert report suggesting that the tracks needed to be repaired.
"About 5 per cent of Luas track will require remediation to eliminate the risk of any significant long-term deterioration. The track continues to be monitored on a weekly basis," according to a spokesman for the RPA.
The agency denied that track-widening on the Luas lines was likely in the medium term. "Two of the world's leading track experts have reported on the Luas track issue. Both carried out extensive on-site and laboratory tests, and have confirmed that the system is safe.
"However, they do recommend ongoing monitoring of the situation, and appropriate remedial works in due course."
An agency spokesman also said the contractor had accepted responsibility for carrying out the repair works, and there would be no cost to the taxpayer.
Last week The Irish Times revealed the contents of a report by two academics from the Institute for Railway Engineering at Graz University in Austria into the Luas system. It was carried out on behalf of AMB Joint Ventures, the contractors who built the lines.
It emerged yesterday that the RPA also commissioned its own study into the problems last year. Three reports from a railway expert in Munich alerted the agency to the problems with the bonding material in the concrete blocks holding the tracks in place.
The agency-commissioned study found that there could be excessive widening of the tracks in certain conditions, but, like the contractor's report, it said there was no immediate safety issue. It suggested repair work be carried out as soon as possible.
The RPA spokesman said last night that plans for the remedial works were being finalised, and the contractor had been instructed that disruption to passenger services must be kept to a minimum.
"The Railway Safety Commission has been kept fully informed throughout, and considers RPA management of this issue prudent and reasonable," he said.