In Conor McPherson’s bittersweet play Port Authority, now being staged by the Irish Repertory Theatre in its temporary new home off Union Square, we meet three generations of Irishmen who are at the ends of their respective emotional ropes.

As the play progresses we also realize that they don’t know or see each other, and they won’t talk to each other onstage. That makes perfect sense. If they could they might actually have to confront the frozen wasteland they’ve made of their own lives by staying silent when they should have spoken up.

McPherson decides that to be true to his quietly thwarted characters he has to keep those confrontations from occurring. So the only thing that links the three men in Port Authority is emotional damage, the damage that comes from living in a suffocating society that says this is what a man is, and all he ever can be. And in a way it’s their own fault too, for agreeing with that decision – insofar as they do.

Director Ciaran O’Reilly has given the Rep’s deceptively low key season opener a bravura fast moving production, which also takes the time to let the most intimate and human scale emotions rise to the top.

Casting gifted Northern Irish actor Billy Carter, 38, as Dermot, the sad sack husband and father who is completely out of his depth in the high flying new job he’s just landed is O’Reilly’s most inspired gamble, one that pays off handsomely.

Carter, born and raised in Bangor, Co. Down, is playing against type as this luckless working class Dubliner. For a start he’s from Northern Ireland so the accent work involved is considerable, but he’s also physically younger than the part seems to demand, so he has his work cut out for him from the moment the lights go down.

“The part is so far from removed from me,” Carter tells the Irish Voice, clearly delighted by the challenge.

“Before I was cast I was just in London playing this big part in an incredibly camp musical (The X Factor Musical, based on the behind the scenes antics of the hit TV show) and so when I came back to the USA I was looking for a role that went slightly against the grain. Then this came up.”

As a change in tone Port Authority is about as far from The X Factor Musical and the West End as you can get. In London Carter played a flamboyant gay man; in New York he plays a browbeaten Irish husband. It’s the kind of challenge that keeps things interesting as he gets to grips with his exciting new New York life after two decades of living in London.

“I’m a bit of a virgin in New York still, I’m still finding my feet. I got my green card two years ago and I’ve moved here full time,” Carter says. “The Irish Rep has been very good to me. It’s work that I’ve wanted to do and it’s given me a nice little platform in the city.”

The exposure has done wonders for his career. Carter especially enjoys working with O’Reilly and has developed a creative shorthand with the celebrated director, having previously appeared in his massively successful production of McPherson’s The Weir.

But appearing off Broadway is a long way from where he started. In Northern Ireland the path to a career in the arts is especially perilous, making eventual success 10 times more impressive.

“I wasn’t academic at school at all,” he confesses. “I left when I was 16. Then I faffed around a bit until I got very heavily involved with the local Bangor drama group and the local operatic society.

“I used to do a little bit of stand up to at working men’s clubs in Belfast too. Theater was my get out clause, to be honest with you, to be able to move away. Acting was something I really tapped into from a very early age.”

In his early twenties Carter went over to London to train as an actor thinking he would return to Northern Ireland when he was done, but being a young man he soon saw the point of staying. That’s when his career took off.

Carter’s first introduction to New York was playing on Broadway, no less. He arrived in a production of Eugene O’Neill’s A Moon for the Misbegotten in 2007, starring opposite Kevin Spacey and Colm Meaney.

“After that experience I returned to London slightly deflated because I had wanted to stay here. So I got a lawyer. The acting game has been my ticket to a wider world,” Carter says.

“I have a nice little career in London and I’ve been able to work with all the people I do. When I came to New York I met a very nice community of actors here. We’re all complaining about the same thing.”

Although he knows Irish theater and has appeared in major Irish productions, as it happens Carter has not done much of McPherson’s work before.

“I’ve done a lot of Brian Friel’s plays and Frank McGuinness’s (Carter was nominated as Best Actor by the London Theatre Awards for his performance as Edward in Someone to Watch Over Me) but not McPherson’s.”

In London especially he played a lot of English parts he says, but playing Irish roles taught him where what he calls his emotional bolt is.

“I know men like Dermot in Port Authority. He’s such a tragic character. The way it’s written has brutal honesty. They’re like confessions really.”

Finding the time in his busy schedule to rehearse part was the most challenging aspect of the production. For the first two weeks of rehearsals Carter was away filming in Bucharest for the History Channel, which makes the powerful central performance he’s turning out on the Rep stage now all the more remarkable.

“It’s amazing what a bit of fear can do for you,” he laughs. “I had to make up the ground very quickly. Dermot is a very tragic fella, even from his wife’s point of view.

“We actually learn she dated and married him in a sort of act of compassion. That’s a shocking realization. None of the characters try to hide themselves. They let you know what happened to them.”

What’s particularly interesting about Port Authority from an actor’s point of view onstage is that they can feel the stillness in the room when the actors are telling their stories.

“You can feel the audience coming with you. It can be a little naked and a little terrifying,” Carter says.

Joined onstage by James Russell as Kevin, a twenty-something lovelorn young man who can’t find it in himself to say how deeply he’s in love with the girl who’s only waiting to hear him say the word, and Peter Maloney as Joe, the retirement aged man who let the greatest love of his life pass by without a word, their respective silence in the face of suffering is the thing that most impresses Carter. It’s a silence he wants to resist in his own life.

“When I’m back in Ireland I do find myself editing things out,” he confesses. “My mother hates it if she thinks I’m showing off. You revert back to your late teens when you go back.

“When you’re coming back from America where everyone tells you everything about themselves to a place where you often can’t say a word, it can be quite a shock.”

Port Authority is playing at the DR2 Theatre, 103 East 15th Street. For tickets call 212-727-2737 or click here.