LUAS bosses have rejected calls from Dublin City Council to put power lines underground, writes Paul Melia.
The council opposed plans to use overhead power cables in the proposed link-up of the two Luas lines because of their impact on the capital's architectural heritage.
But the Railway Procurement Agency (RPA), which plans to link the Sandyford and Tallaght lines, rejected the council submission, as it could cost "tens of millions" of euro.
The overhead lines would have to be removed from more than 35km of track and replaced with an underground system, which would add considerable expense to the project.
The RPA also said that underground power lines were "unproven" technology and it could not gamble that they would work.
In a submission to An Bord Pleanala, the city council said the Luas would travel from St Stephen's Green to Dawson Street, College College, across O'Connell Street and to Parnell Square and pass by some of the city's most significant buildings.
College Green had a "progression of exceptional classical buildings", including the Bank of Ireland, and they should not be compromised by cables and wires, it said.
An Bord Pleanala is expected to announce a public hearing into the project in the coming weeks. Planning permission was sought last June to construct the link, called Luas Line BXD.