Five years before Quebec closed part of the Mercier Bridge due to dangerously deteriorating steel plates on the span’s provincial side, an inspection found plates on the federal side were corroding and had to be replaced.
The report said repairing the plates – steel connectors that hold together the bridge’s girders and beams – should be a top priority.
“These gusset plates play a major role in the integrity of the bridge structure,” the report stated. “Therefore, the progress of corrosion at these plates must be monitored, and, if necessary, a capacity assessment should be done to evaluate more accurately the behavior of the material affected by the corrosion.”
The inspections were commissioned by Jacques Cartier and Champlain Bridges Inc., which owns the federal side of the Mercier.
Ottawa reinforced about 50 gussets in 2008, replacing two and repairing the rest. Meanwhile, Quebec, long criticized for neglecting transportation infrastructure, decided not to do work on its gussets.
The Mercier’s federal half was built in the late 1950s, while the provincial part that was closed for gusset repairs went up in the early 1930s.
The 2006 report, by an engineering firm, paints a troubling picture of the Mercier at the time.
For example, it warns the bridge’s side curbs and median were so deteriorated that cars that accidentally plowed into them could be launched into oncoming traffic or off the bridge.
Follow-up federal inspections in 2007, 2008 and 2009 also disclosed in response to the access-to-info request, found that repairs helped improve the overall condition of the bridge’s federal half.
The disclosure that federal officials were advised about gusset deterioration as early as 2006 is another indication Transport Quebec may have missed crucial corrosion on the provincial side.
If the deterioration had been caught earlier, traffic disruptions that affected tens of thousands of commuters during the Mercier closing could have been avoided.
To fix its gusset plates, Transport Quebec closed two of the Mercier’s four lanes on June 14. One of the closed lanes reopened Sept. 6. But, to allow for ongoing gusset work, the bridge still goes down to two lanes overnight and on weekends. All four lanes are to be permanently reopened by December.
This summer, Quebec initially refused to make public the inspection of its side of the Mercier, finally relenting in September under pressure from the public, engineers, politicians and the media.
In September, Transport Minister Pierre Moreau said provincial plates deteriorated “at a faster rate than what was expected” and the damage could not have been caught earlier.
Independent engineers question this version of events, noting corrosion does not speed up.
The 2006 inspection report recommended 37 repairs, nine of which were classified as “A” priority jobs, meaning they were “necessary to maintain the integrity of the system’s structure and of its auxiliary components.”
The first item on the list of top-priority repairs: gusset plates, which, the report said, should be reinforced by 2010.
The report recommended close to $32 million in federal repairs.
The $74-million federal expenditure is part of a $174-million Mercier overhaul that Ottawa and Quebec began in 2008 and that is to be completed by 2014. Quebec has not said how much it has spent on the project so far.
The 2006 federal inspection was the last general inspection of the bridge.