The builders of the $523 million North Shore Connector, which is to open to the public Sunday, have won the Alliant Build America Award.

North Shore Constructors, a consortium of contracting firms, is among 16 recipients to have “demonstrated the very best when it comes to building a better America,” according to the Associated General Contractors (AGC) of America, the group bestowing the honor.

AGC spokesman Brian Turmail said the complexity of the connector project impressed the judges.

“That there was essentially zero margin for error in the tunneling work that needed to be done or risk either creating a leak in the tunnel underneath the river, or actually undermining the foundations of some large and historically significant buildings in Downtown and the North Shore side of Pittsburgh.”

The connector links the Port Authority's subway at the downtown Gateway Station to 2 stops on the North Shore at PNC Park and Heinz Field.

Recipients were chosen by a panel of experts in various fields of construction. Turmail said they evaluated each project based on complexity, innovative techniques, and coordination with partners.

He said the connector gives contractors the ability to demonstrate their mastery of construction.

“They had to thread a very, very, very narrow needle through an extremely small hole and do it without margin of error, which gets really complex when you’re talking about construction and essentially digging a large hole in the ground,” said Turmail. “You got to do it exactly right; there was no margin to get this wrong.” 

Turmail said a lot of this year’s award winners were publicly funded like a renovation to the Pentagon, and the U.S. Consulate in Tijuana, Mexico.