EXPERTS have warned that cracked concrete discovered on the route of Edinburgh’s tram line just hours after testing began could become a serious maintenance problem.
The cracking was found by the Evening News in concrete under an elevated section of track close to the Edinburgh Park tram stop.
The fault was discovered as contractors were walking alongside one of the trams, which was making its maiden journey from the Gogar depot to Edinburgh Park on Tuesday in a new phase of the testing programme.
The discovery is the latest problem for the £776 million project, which had appeared otherwise on track - according to the council’s revised timescale - to leave a history of budget blowouts and management errors behind it ahead of next year’s service launch.
An Edinburgh-based chartered structural engineer firm, which did not want to be named, said the cracking was “most likely associated with shrinkage after casting the concrete”. A written assessment of the damage said: “I would imagine that the contractor should be asked to confirm the cause and provide a solution for remedial work.”
A “soft spot” in the concrete base that had cracked when it took the load of a tram for the first time was cited as the other likely cause.
Professor Lewis Lesley, technical director of light rail company Trampower, said it was clear expansion joints had not been added to the concrete.
He said: “What will happen is the reinforcement wires will rust and then the concrete will break apart. It’s clearly going to be a maintenance problem.
“They would need to check for any further cracks and fill them with an epoxy cement grout, but it indicates that this is a bit of a rushed job and they didn’t quite get it right.”
The council said the problem would be monitored, but did not confirm the cost or time needed to fix the fault. The affected stretch of track has largely been finished, but is still being managed by contractors.
Green transport spokesman Councillor Nigel Bagshaw said: “If there’s a problem with the way the track has been laid then it’s for the contractor to put it right as soon as possible – and check whether it has occurred elsewhere – in order to avoid any further delay to the overall tram project.”
Transport expert Simon Johnston, editor of Tramways and Urban Transit magazine, said tram testing was designed to pick up not only problems linked to the vehicles, but with the track itself.
He pointed out there had been similar problems with Dublin’s tram system found during the testing phase, saying: “It’s not that unusual for them to find things like this, but of course remedial works are going to have to be carried out.”
A council spokesman said: “Cracking within concrete is common and the majority of cracks, such as this one, have no structural influence on performance.
“The contractor and the council have a monitoring process in place for this type of thing and, of course, all aspects of the tram system will be thoroughly tested and checked before we go into operation.”
A ROCK AND A HARD PLACE
CONCRETE had to be replaced as many as three times on Shandwick Place after bungled jobs that failed to pass quality tests.
Contractors were told to cover the extra costs after tram workers were found to have poured incorrect concrete levels in the West End across a stretch up to 500 metres long.
Sleepers used to stabilise the tracks were then cracked during drilling to remove the rest of the incorrectly laid concrete from Shandwick Place to Haymarket.
Repairs along the stretch took four months to finish.
Manor Place to Shandwick Place will be the final section of road to reopen, with traffic to return to normal along the stretch from next Saturday.