Cheers erupted from the hundreds of workers gathered at the Irving-owned Halifax Shipyard on Wednesday as the federal government announced it had been awarded the $25-billion contract to build 21 Canadian combat ships.

"It's Christmas. It's unbelievable," said Jamie Vaslet of the CAW Marine Workers Federation.

"When I started here 31 years ago and it was up and down and up and down and now the kids that are coming in here today, they can actually look at retiring here. It's amazing."

Vancouver's Seaspan Marine was awarded an $8-billion contract for seven non-combat vessels, while the Davie Shipyard in Lévis, Que. was shut out of the two larger contracts.

The Davie Shipyard is still eligible to bid on further contracts worth $2 billion in total, to build smaller ships. Irving Shipbuilding and Seaspan Marine are not eligible to bid on that work.

Nova Scotia Premier Darrell Dexter called the announcement a historic one for the province.

"Oct. 19, 2011 will go down as one of the proudest days in Nova Scotia's history. The day we capitalized on the waters that surround us to build a brighter future for Nova Scotia and for Canada," Dexter said to cheers from shipyard workers.

Dexter said families that have moved out west for work will now be able to come back to Nova Scotia as a result of the thousands of jobs that will flow from this single announcement — the largest military procurement in modern Canadian history.

"It means that young people now can plan on a career staying here in Nova Scotia," he told reporters.

Raymond Dart, a 35-year veteran in the shipbuilding industry, was one of hundreds of workers crammed under a tent at the Halifax Shipyard listening to the announcement made by Francois Guimont, the top civil servant from Public Works and Government Services.

Halifax Shipyard won 'fair and square': Irving

"I have three kids in here. Two of them are laid off right now, one of them is still here but it's going to mean a lot of work for them," Dart told CBC News.

"It means they can go ahead and do what they dreamed to do. Buy a house, plan a family, give me some grandchildren," he said, chuckling.

There are currently about 800 workers at the Halifax Shipyard.

A study commissioned by the Greater Halifax Partnership said Halifax winning the big contract would mean 11,500 jobs — both direct and indirect — in the province during the program's peak years. As an average, that's about 8,500 jobs per year for 30 years.

"What this means is we've got a long-term, stable outlook," said Jim Irving, the CEO of Irving Shipbuilding.

"These are big, capital intensive jobs and when you can plan these long-term jobs out in the future it gives you great stability."

Irving said he believed his shipyard won "fair and square."

"I think the fundamental piece is people. We've got a very good team. We've got great shipbuilders. Tradespeople. Men and women in the yard, dedicated and hardworking folks and our management team has worked very hard," he said.

Irving said if things stay on track, workers will be cutting steel for the new ships in late 2012 or early 2013.

"We were sure we were going to win but it's just like the lotto," said Vaslet.

"We hit it."