Hundreds of Irish workers are at the center of London's underground Crossrail project - a massive €17.3 ($23.15) billion tunneling project that was started in 2009.

According to a project spokesperson, several hundred Irish workers are employed across the Crossrail's multiple worksites. The total workforce is over 9,000.

John Small, a 39-year-old construction manager from Coolarty, Granard in Longford, has been working on the project for McNicholas Construction for six months. With nearly 20 years experience in tunnelling and construction, he told that he is helping other Irish construction workers find jobs at Crossrail.

He said the work is hard, but the money is good, and that entry-level workers make an average of £210 ($281) per day. Small says he's helped up to 400 workers in the past six months.

“You can’t get into this tunnel work unless you’ve a CV right,” he says. “There’ll be lads coming over and finding you – to find out what’s going on. You’ve got to get your cards right – you can’t move without a card in London, and they might not know how to make the best of their skills when putting them into a CV.”

"In this line of work too – everyone knows each other. Once a job starts I’ll be ringing you or vice-versa, and we’ll open a whole can of worms and we’ll know exactly who’s the boss and who you have to apply to for these jobs. We’ll have all the inside information. You’ve lots of boys from Donegal, Mayo, Connemara – other parts of the country too. When a job starts we’d all be aware."

Donegal-native John McNulty, who owns a pub called 'Lucky 7' in the north west of London and who is a former 'tunnel man' himself, says he frequently gets calls to the pub from firms looking to hire skilled workers.

"Just the other day the phone rang saying they were looking for four machine drivers. They’re looking for everything – everything from labourers to electricians.

McNulty says young Irish men often turn up at the bar looking for work.

“You even get guys coming back from Australia, parts of Australia where they find it may not have been as good as they expected, and taking up work here," he said.

"The pub is full of workers. All the talk is about work – maybe a few pints in between but mostly work work. When they talk about back home the feeling is things may be picking up a bit in Dublin but not in Cork or Kerry or Donegal. But they’re more than happy to be here.

The construction project has unearthed jewelry, skeletons that were once victims of the plague, pieces of ships and even medieval ice skates. Archaeological investigations, which are being overseen by the Museum of London, are being carried out at each location.

Said Small: "We’re told not to touch the remains. We know in advance where they’re likely to be. We’re not allowed to take photographs or anything. What happens is the Museum of London staff – they’re there full time – they come in and they take over and start doing the digging themselves."

The Crossrail, which is due to open in 2018 will run across London from west to east, with a central 21km section underground, reports Programme Director Andy Mitchell has said it will "overnight, increase the capacity of rail in London by 10 per cent – the biggest single expansion ever.”