Another report on problems with the Luas tracks has come into possession of The Irish Times. This report deals with the repairs necessary to ensure that bends on the tracks can be made safe in the long term.
The assessment of a system of repair using direct fastenings on the Luas track, commissioned by the company that carried out the construction, was carried out by experts in Utrecht in the Netherlands.
The purpose of the study was to establish if track fastenings could be used to tie the track to the concrete supports underneath in the light of the faulty bonding material identified in the first report revealed in The Irish Times.
It found that the concrete supports would need to be manufactured to a very high standard to take the horizontal forces. It said problems had arisen with track fastenings in Antwerp where a non- reinforced mortar layer began to crack shortly after the track went into service. Damage occurred at most fastenings.
"The plinth design must allow for tensile forces around the anchor to be taken, making reinforcement necessary. Furthermore, the correct construction of the plinth is very important taken the high load concentrations.
"The quality of the constructed plinth, including the flatness of the surface, should be checked. A construction method whereby the plinth is constructed by pouring under the baseplate pad is advised against. The connection between the plinth and the foundation is of importance for a correct load distribution."
The study concluded that as far as the Dublin tracks were concerned, the mortar plinth would have to be replaced by a reinforced concrete plinth that was constructed before the baseplate and baseplate pad were put in place. As long as the concrete supports were built to the right specifications, the Dublin light rail system would be "fit for purpose".
