Despite the observed loss of resistance on cables and work sometimes carried out in an emergency, there is no doubt about the safety of the Pierre Laporte Bridge and, according to an engineer, it could “easily” last half a century if taken care of by the Ministry of Transport.
• Also read: No third link is required, we already have two bridges!
“Suspension bridges are bridges that are designed to last a very long time. If you take care of it, you can keep it for a long time. That’s exactly what we’re doing at the moment,” says Carl Fortin, technical coordinator in the major projects department of the Pierre Laporte Bridge.
“So I’m pretty confident that this structure will easily last another 50 years and maybe even longer,” he continues.
Photo Stevens LeBlanc
In an interview with the Journal, the engineer insists that the infrastructure is completely safe, even though the condition of the original trailers has made headlines several times in recent years (see box).
“The Laporte Bridge, if there was a problem, I can tell you that I would be the first to raise the flags and then stand up to say [qu’il] They have to close it, but we’re not there at all. I regularly go over the structure; My family, my friends walk over the structure and I can tell you if it wasn’t safe and there was even the slightest doubt, no one would walk over it,” he says.
Accelerated exchange
The Pierre Laporte Bridge, which turns 53 in November, features 160 hangers, the vertical cables that connect the two long support cables to the deck.
“In the life of a suspension bridge, it is normal for the hangers to wear out and need to be replaced during maintenance,” explains Mr. Fortin.
However, in the summer of 2022, it was discovered that a pipe had lost 57% of its original strength. An $8 million contract to consolidate 28 was subsequently awarded without competitive bidding.
Photo Stevens LeBlanc
The Ministry of Transport and Sustainable Mobility (MTMD) has since accelerated the original 15-year hanger replacement program.
The program must begin at the end of 2024 with the aim of renewing all routes by 2029. Corresponding work is also being carried out.
Since 2015, 27 lines have been replaced with new ones, 12 of which have been in the last two years.
The remaining 133 lines were never changed. Since 2022, 37 of these have been strengthened or reinforced with temporary hangers. A tender is currently underway for 13 more trailers.
“100%” secure lines
“Security [que les suspentes sont sécuritaires]“For me it is 100%,” explains Carl Fortin, emphasizing that “the Ministry of Transport will never hesitate to close a structure if it is dangerous”.
Every line taken is systematically analyzed in the laboratory, he explains.
Of those already replaced, only two had lost more than 50% of their resistance – including the one that caught the attention. Despite everything, they had not reached a risk factor that was considered critical, he said.
Photo Stevens LeBlanc
“Not all pipes are in this condition. That was the worst lockdown. The resistance is different,” he claims, believing that “we have to take care of the lines” but that the situation is not worrying.
Others, less damaged, still showed up to 96% of their original resistance.
“We don’t stand behind what’s being done elsewhere,” says Mr. Fortin. He cites the example of the Macdonald Bridge in Halifax, whose suspensions were replaced after 60 years, and the Ambassador Bridge in Detroit, for which we waited almost 100 years.
“We are there and we are not worried about the results,” he believes.
The hangers of the Pierre Laporte Bridge
- The factory has 160 hangers
- 27 have already been replaced
- 37 were secured
- A tender is underway to secure 13 more
- The full replacement and other related work is scheduled to be completed in 2029
- They are checked every year
Source: Ministry of Transport and Sustainable Mobility (MTMD)
Lots of twists and turns
November 25, 2021: Two hangers need to be replaced quickly before winter due to “accelerated wear and tear.” Heavy trucks can no longer use the right lane in every direction.
June 15, 2022: A report published by Radio-Canada recommends complete replacement of the pipes as soon as possible due to uncertainty about their condition. One hanger analyzed lost 57% of its original capacity. Minister François Bonnardel announced the next day that the work plan would be accelerated.
August 2, 2022: We learned that the Department of Transportation had awarded an emergency no-bid contract for $8 million to consolidate 28 hangers.
September 13, 2022: The painting and metallization work was put on hold in order not to put additional strain on the bridge during the replacement of the hangers, which was considered a priority. Mayor Bruno Marchand regrets that the missing information gives the impression that the file is “a mess.”
April 6, 2023 : Work on attaching the hangers can be resumed. They had been suspended for several weeks “due to health and safety issues for workers.”
July 11, 2023: The Ministry of Transport and Sustainable Mobility is finalizing a nearly $80 million contract with a consortium to support the Pierre Laporte Bridge, maintain safety and “maximize” its lifespan.
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