Leaks mean further setback for tunnel

CONGESTION-weary motorists face another delay in the opening of the long-awaited Port Tunnel after a snag list revealed flawed roof panels and leaks.

Repairs are underway to replace the faulty panels and seal off the source of leaks into the passageways which were due to open to traffic in three months time.

A revised schedule now puts the opening back to some time this summer, but that relies on Dublin City Council's predictions that the problems discovered are "localised" and will not appear elsewhere.

The trouble was discovered when the concrete panels lining the tunnel were x-rayed during routine quality control checks in preparation for the planned opening of the route in April.

Dublin city deputy engineer Tim Brick said the panels were supposed to be between 300-400mm in thickness but some lining the roof in one section were found to be less than the minimum.

"In one of the cross passages in the tunnel, a small section of concrete had to be removed because it was defective and when it was removed, it exposed the rock behind which was carrying water and was leaking into the tunnel," he said.

Dublin City Council said the leakage of water through rock was a natural phenomenon and was not the fault of the contractors but they had begun sealing fissures in the rock with grout.

The contractors were responsible for the flawed panelling, however, and had undertaken to replace it. Mr Brick said the repairs were expected to take another week or two.

He described the discovery as "upsetting" but said it was confined to an area measuring about four square metres and raised no safety concerns. He confirmed that a similar problem had been resolved after it was discovered in August 2004.

A council official described the leaks as "comparable to one running tap in a tunnel nine kilometres long." Seepage of rainwater was a feature of all tunnels and the required drainage and pumping system was in place to deal with it, the official said.

Some of the water witnessed in the tunnel was there from the construction period before the structure was sealed and would not return once it had been pumped out.

The current problems are just one in a series of headaches for the tunnel since the contract was awarded for its construction in late 2000. Residents along the route of the tunnel have lodged 230 compensation claims for damage caused by the tunnelling beneath their homes.

The Government has also been repeatedly criticised for failing to order a redesign when it was discovered the tunnel was too small to accommodate the so-called supertrucks used by major British retailers such as Tesco to transport goods.

The project has also cost more than twice its original €448 million estimate and Dublin City Council is in dispute with the main contractors over a new invoice submitted which would add a further €444m to the bill.