The tunnelling of the underground section of the Metrolink is set to run under the Houses of the Oireachtas creating a noise akin to “a washing machine” for the duration of its construction, public representatives have been told.

The revised Metrolink plan, which was announced last Tuesday, is set to include an underground tunnel beneath Leinster House which will run between the Tara Street and St Stephen’s Green stations.

Public representatives attending a private briefing held by the National Transport Authority (NTA) last week raised concerns around the level of noise pollution that would be caused by the construction of this underground tunnel.

Former minister for justice Michael McDowell, who attended Tuesday’s meeting, told The Irish Times he was one of a few attendees who raised the issue of noise disruption at Dáil Éireann which, he was told, “would be equivalent to having a washing machine in the room next door”.

“It’s a tunnel and to build a tunnel anywhere in Dublin it’s going to make a lot of noise for anyone nearby,” said Mr McDowall.

“I live beside the Luas and if you live in the city you have to accept that noise.” He said he had joked at the meeting that the decision to tunnel below Government buildings had “a bit of a Guy Fawkes feel to it”.

The briefing, which was held by senior National Transport Authority and Transport Infrastructure Ireland (TII) representatives, did not hear comment on how long the construction beneath Leinster House would take.

‘Farcical suggestion’

The NTA confirmed last week that the metro, which had been due to run from Swords to Sandyford, will terminate at Charlemont north of Ranelagh where it meets the Luas Green line.

The NTA said it would tunnel past the Charlemont stop to allow the conversion of the Luas to metro “to occur at an appropriate point in future” but that the upgrade would not be required “for some time – perhaps 20 years or so”.

Speaking in response to a question from Green Party leader Eamon Ryan on the extension of the metro to Sandyford via UCD, Taoiseach Leo Varadkar said on Tuesday he would be open to considering the proposal but did not want to “hold up the project” any further.

Mr McDowall said there would “clearly be a delay” if the entire line was rerouted and described the Taoiseach’s consideration of the project as a “farcical suggestion” given that the NTA were intent on constructing a tunnel beyond the Charlemont stop.

Building this tunnel for future construction would be “completely inconsistent” with rerouting the line to Belfield, he said.

“I’m relaxed about the tunnel, it would make no difference to me. I wouldn’t see it or be aware of it. What I’m against is the cannibalisation of the Green Line into a metro station. But if you’re going to reroute it there clearly will be a delay.”

Mr Ryan, who also attended Tuesday’s private briefing, said the NTA was engaging with his proposal of turning the metro line southeast once it reaches Charlemont and sending it in the direction of UCD en route to Sandyford.

He proposed the metro would stop off at four stations; Donnybrook, where the bus garage could be redeveloped to include a station; UCD, directly connecting the university with Trinity and DCU; Stillorgan where there are “huge sites for development” and finishing up at Sandyford.

“The advantage of that is you can manage the increase in capacity that we will need on the Green line,” Mr Ryan told the Irish Times.

“All the growth will be from Sandyford and further south. It’s about four stations, it’s about six kilometres and it’s eminently doable.

“You don’t need a whole new strategy, this is a public consultation exercise. I don’t think there has to be a big delay. I think it’s now a political issue for the Government to ask the NTA to look at this and to give them the necessary direction so it doesn’t get stuck in glue. I’m hopeful that may well now come to pass.”