CHAMPLAIN BRIDGE

EXTREME MEASURES are being taken to repair new cracks. One thing is certain: This will be painful.

The patient’s condition is deteriorating quickly. Extreme measures must be taken.

After more cracks were found on an already-fissured Champlain Bridge beam, federal officials have closed another southbound lane on the span, sparking an even bigger traffic crisis that will last until at least mid-December.

That’s bad news for the people in the 160,000 vehicles that cross the Champlain daily.

To reinforce the rapidly deteriorating beam, the federal bridge authority will have to use two techniques that it has never tried before.

The announcements followed last week’s decision to close the left-hand southbound lane after a first dangerous crack was found.

That closing has caused traffic chaos, particularly during the afternoon rush hour toward the South Shore.

On Friday, the sudden closing of a second lane caused a kilometres-long traffic jam on the Montreal approach to the Champlain, as cars, trucks and buses squeezed into one southbound lane on the bridge.

On Monday, the pain will be felt on the Montreal-bound side, as it will be down to two lanes. Normally, in morning rush hour there are three car/truck lanes to Montreal, plus a lane for buses.

Despite the grim news and extraordinary reinforcement measures, the general manager of the Jacques Cartier and Champlain Bridges Inc. insisted the bridge is safe.

“The problem beam is connected to six other beams. They are knit together. The other six beams are behaving very well, and they and the piers are supporting this problem beam,” Glen Carlin said.

“The fact that we’re finding ourselves with two lanes closed is an indication that we are being very prudent. If necessary, if it comes down to that, we will close a third and fourth lane to ensure the safety of the public.”

The beam in question runs along part of the edge of the bridge’s deck. It is one-third of the way from Nuns’ Island toward the South Shore.

A two-phase reinforcement plan is in the works.

Phase One of the repair strategy will involve the installation of a “super beam” above the cracked beam.

The federal bridge authority has had one of these enormous steel beams ready since 2009 for such an emergency. Until now it has not been needed. Two more are on or- der and are to be delivered next year.

The super beam will be installed on top of the Champlain and then fastened in six spots to the cracked beam under the bridge, Carlin said.

By mid-December, the first phase should allow all three southbound lanes to open, though they will be narrower and the speed limit could be lower than usual, he said.

In the spring, Phase 2 kicks in.

When the weather improves, workers will install a “modular truss” under the cracked beam.

That truss will act as a sort of external skeleton for the problem beam, providing reinforcement from below.

The bridge authority has a modular truss on standby but has never needed to install one before.

Once the truss is in place, the super-beam is to be removed.

With the truss installed, all lanes are to reopen at their regular width and speed limit.