Operators of Dublin's Luas system today insisted that flaws found on suburban sections of track are not an immediate risk to public safety and repair work is not urgent.
Ger Hannon, RPA
An engineering study commissioned by the system's builders, AMB Joint Ventures, found that nearly five miles of both the Red and Green Line had deficiencies in the underlying bonding material.
The polymer/cork substance is designed to reduce noise and vibration at certain sections of track. But particularly where the tracks turn around bends the bonding is separating leading to cracks allowing water in.
"The debonding is gradually more serious with sharper curvatures of the alignment and manifests itself by opening of fissures and cracks which permit penetration of water into the load carrying system," the report says.
Safety is not yet affected but it warns that left untreated "reliability and proper functioning of the system" would be "uncertain".
The report recommends a number of measures be taken to strengthen the track structure and the Rail Procurement Agency said today the repairs would be carried out shortly and should not affect services.
RPA spokesman Ger Hannon said the flaws were only present on accessible suburban sections of track and not at city centre locations. The affected sections are mounted on concrete slabs and attached by metal clips, such as along the Grand Canal on Davitt Road.
When the work is completed, AMB will be able to guarantee the lines for up to 50 years with minimal maintenance.
"We can carry out the work over the next few months and it should take place over several weeks depending on the level of resources we apply to it," Mr Hannon said.
"We need to know that this work will last 50 years. The work should not involve disruption and passengers shouldn't know that it's going on.
"It will be carried out at no extra cost to the Exchequer."
The engineering study was carried out by the Institute for Railway Engineering at the University of Graz in Austria.
Additional reporting PA