Report raises concerns about Pierre Laporte Bridge safety

Report raises concerns about Pierre Laporte Bridge safety

Ruby Pratka, Local Journalism Initiative reporter

ruby@qctonline.com

Provincial officials have been scrambling to reassure Quebecers about the safety of the Pierre Laporte Bridge over the past week, after a Radio-Canada report raised concerns about the viability of some of the 160 suspension cables that hold the bridge in place.

The report, by journalist Marie-Pier Bouchard and based on information obtained by journalists working for the network’s flagship investigative show, Enquête, alleges that the cables holding up the giant suspension bridge are “weaker than they’ve ever been,” accord- ing to the results of recent stress tests carried out in a lab at Montreal’s École Polytechnique.

“Every suspension line is composed of two vertical steel cables that link the two immense carrying cables to the bridge deck,” Bouchard wrote. “Two of the five lines were urgently replaced last fall and one of the cables had lost 57 per cent of its original strength. … The test consists of gradually pulling on each cable until it breaks, which makes it possible to know its residual resistance.” A report by two engineers from the Ministry of Transport (MTQ), obtained by Enquête and based on test results over the past few months, found that a “significant and rapid deterioration” of the resistance of the suspension lines had been observed. The report’s authors recommended that the cables be replaced “sooner rather than later.” Furthermore, Enquête revealed that MTQ engineers had been calling for some of the cables to be replaced as early as 2016. Last year’s replacement of two cables resulted in weeks of disruption to traffic on the bridge.

In the wake of the Radio- Canada report, the MTQ announced its intention to “accelerate” the planned replacement of the cables.

“If there was the least doubt about the safety of the Pierre Laporte Bridge, we would not hesitate to modify traffic rules, reduce the allowed load or close the bridge, despite the disruptions that may result,” the MTQ said in a statement. “We are taking the information recently made public very seriously.”

The statement added that thorough inspections of the bridge are conducted “at least every two years” and contracts had already been issued for the “consolidation” of existing suspension lines and the replacement of 19 suspension lines over the next three years. “The MTQ is aware that the Pierre Laporte Bridge is a key link for the greater Quebec City region, and all the necessary measures are being taken to ensure that it remains functional for the coming decades,” the statement said.

Premier François Legault and Transport Minister François Bonnardel have assured the public that the bridge is safe. The MTQ and the Association professionnelle des ingénieurs du gouvernement du Québec did not respond to inquiries from the QCT by press time.

The Pierre Laporte Bridge, the longest suspension bridge in Canada, opened to traffic in 1970. An estimated 125,000 vehicles cross the bridge each day.