THE sound-proofing roof tiles in the €751m Dublin Port Tunnel are set to be removed -- because they keep falling down and won't stick on.
Hundreds of foam tiles on the roof of the tunnel are to be taken down this weekend after they started to fall down on trucks, sparking potential safety concerns.
More than 300 metres of the soundproofing tiles will be removed and the area painted instead.
When the foam tiles starting falling down there were immediate concerns that there was a potential safety risk as drivers might believe they were concrete and swerve suddenly to avoid them.
When the authorities tried to stick them back up, they just fell down again. The tiles cover part of the side walls and the roof of the tunnel for the first 150 metres in each direction and were designed to reduce the noise of the trucks as they entered and left the tunnel.
But the National Roads Authority (NRA) decided they were also of limited use for this purpose and the falling tiles caused major maintenance headaches.
A NRA spokesman said the cost involved in removing the tiles would not be significant and would be accommodated in the maintenance budget for the tunnel.
The authority said that as part of the tunnel construction, acoustic foam tiles were placed on the roof of the tunnel for 150 metres on either approach to evaluate their effectiveness in absorbing the noise of vehicles passing through. The NRA said they reviewed the effectiveness of the tiles and concluded they were of limited value.
The tiles were also causing a significant workload as they kept falling off and had to be stuck back on.
However, even with the adhesive, the tiles continued to fall off.
The upshot is that the authority decided to remove the tiles and coat the empty spaces with ceramic paint. The operation will take place tonight and tomorrow during the routine night-time shutdown for maintenance.
The tunnel, which opened in December 2006 at a cost of €751m, has removed more than 6,000 trucks from the city's quays.
However, the truckers are forced instead to use the congested M50 to access the tunnel and Dublin Port.