Cracks in Montreal metro’s green line tunnel observed almost two weeks before closure

Montreal’s transit system (Société de transport de Montréal – STM) has confirmed to CityNews Montreal that its crews originally found the cracks in the tunnel between Berri-UQAM and Saint-Laurent stations of the metro’s green line during a routine inspection on April 13 – almost two weeks before Monday’s sudden closure.

“On April 13, during a routine inspection, cracks were observed in the vault of the intertunnel between the Berri-UQAM and Saint-Laurent stations,” wrote Justine Lord-Dufour, STM spokesperson to CityNews Montreal by email. “Following further assessment, we noticed water infiltration. It is worth remembering that it is normal for there to be water infiltration in all types of underground installations, and we have a whole system in place to manage water in our network.”

The STM then contacted the city to request that the water be turned off at this location to allow them to dry out the vault.

“After a few days of drying,” continues the STM spokesperson, “an additional assessment was carried out and led us to the preventive measures that we took on Monday, April 24, including the temporary closure of the green line between the Lionel-Groulx and Frontenac stations, in order to allow a team of structural engineering experts to auscultate, hammer and observe that the degradation of the concrete was superficial and that the integrity of the vault was not in question.”

Montreal’s metro showing signs of aging

On Monday, a major portion of Montreal’s green line of the metro system was initially closed during afternoon rush hour between Lionel-Groulx and Frontenac. Initially, the STM said service would resume at 2 a.m., but then announced that service would remain suspended for an “undetermined period of time.” It was eventually reopened to the public the following morning after 5 a.m. after the inspection showed that the cracks were superficial in nature and did not pose a risk to commuters.

Measures have been taken to ensure the area where the concrete showed cracking was safe and to remove part of the concrete where it was falling.

MORE:

• STM shuts down large portion of green line indefinitely
• Normal service resumes on the metro green line Tuesday morning

“The work made it possible to remove the surface concrete that could fall,” says the STM. “Consequently, we could ensure the resumption of service in complete safety.”

As a preventive measure, a metal fence is also being installed to give crews time to carry out work.

STM officials have acknowledged that Montreal’s 69-kilometre, 68-stop metro system, built in the late 60s, is getting older and steps must be taken to ensure its continued structural integrity.

Back in 2019, the city’s transit authority announced it would spend $1.6 billion to refurbish the aging network, with equipment upgrades, infrastructure repairs and new wheelchair-accessible elevators in a dozen stations.