A huge undertaking in uncharted territory
LAYING the Luas tracks will almost be the easy part.
The first 18 months of construction will be spent moving 70km of utilities, including pipes for electricity, gas, water, traffic signals and telecommunications.
It's a huge job. There'll be 13 separate work sites on Westmoreland Street, and on one section of College Green outside the Bank of Ireland there are 75 separate pipes and ducts.
Despite checking utility records and doing radar investigations, the RPA doesn't know what seven of the pipes are for, so they must tread carefully.
The plan is to move utilities away from the tracks and into the footpaths, in many cases taking ownership of cellars.
"There's a huge number of cellars in Dublin, many of which come to the surface. We've identified 25, but there could be up to 400," project director Michael Sheedy said.
"We could cut the top off the cellar, or acquire part of it. The compensation would be modest, maybe a couple of thousand euro each.
"No matter how good our survey is, not until we open up the ground will we know everything. When we did the Docklands extension, we found a drain which was not recorded.
"You find stuff that's not charted anywhere, including medieval walls on O'Connell Street," he added.
"We've refined our act over the years from doing two Luas lines and three extensions. During the Docklands project, there were lots of utilities but we had no power-outs.
"You can't make an omelette without breaking an egg, but as long as people see you working efficiently, the tolerance threshold goes up. If there's a mess, people get uptight."