UPDATE: Single lane of Nipigon bridge opened to traffic

NIPIGON, Ont. -- Seventeen hours after an expansion joint split on the new Nipigon River Bridge, Trans-Canada traffic is flowing again.

The Ontario Provincial Police opened the eastbound lane of the month-old, cable-stayed bridge to traffic before 9 a.m. Monday.

Bolts holding the girder to the bearing on an expansion joint broke on the bridge’s north side at 3:05 p.m. Sunday. When the bolts released, the cables staying the bridge tightened to support it, raising it about 60 centimetres. 

Early Monday morning, engineers weighed down the bridge with 110 concrete blocks weighing 2,721 kilograms each.

Ministry of Transportation area contracts engineer Gary Weiss said safety was paramount in engineering modeling. He’s confident the added weight will serve as a temporary solution until the cause of the failure can be determined. 

“The one great thing about this bridge is its very flexible and a lot of redundancies are built into this bridge. When things move, they look worse than what they really are,” Weiss said.

“When we built this bridge, we built it so it’s not flat the whole time. We built it on a curve so that the weight brings it back down and comes to rest on the bearings.”

Minister of Northern Development and Mines Michael Gravelle was on site Monday morning. He praised construction efforts that made the bridge passible more quickly than expected.  

“Clearly, we need to understand what happened. Clearly we need to get in place measures so we can ensure it doesn’t happen again,” he said.

“Today, I’m focusing on the rather extraordinary work that has been done by the engineers and the construction people who have been able to get the traffic lane open for all traffic.

‘When this happened, there wasn’t any assurance – let alone clarity – this would be happening with in a 17 hour time frame.”

The new bridge was opened to traffic on Nov. 29 and represents half of a $106-million construction Gravelle has called the “crown jewel” of highway twinning between Thunder Bay and Nipigon.

Demolition has begun on the remaining two lanes of the old highway. The MTO expects construction will be complete in 2017.