A normal resumption of service on the green line of the Montreal metro took place at the end of the night on Tuesday.
In a message posted on its website, the Société de transport de Montréal (STM) explained that after verifications were made by its experts, it was considered safe to resume service between the Lionel-Groulx stations, in the Saint-Henri district, and Frontenac, in Hochelaga-Maisonneuve.
Monday evening, the STM reported that a water leak had detected cracks in the vault of the tunnel between the Berri-UQAM and Saint-Laurent stations, following the assessment of its engineering team.
The public carrier said Tuesday that for more than six hours, there was auscultation, hammering and observation of the vault of the tunnel and that the deterioration of the concrete was considered superficial. The integrity of the vault was therefore not in question.
Work has made it possible to remove the surface concrete that could fall.
As a preventive measure, a metal fence will be installed over the next few nights to give the STM teams time to carry out the work.
The stations that were affected from late Monday afternoon by the service shutdown are all located in the city center. These are the Lionel-Groulx, Atwater, Guy-Concordia, Peel, McGill, Place-des-Arts, Saint-Laurent, Berri-UQAM, Beaudry, Papineau and Frontenac stations.
The STM had asked the City of Montreal to divert heavy vehicle traffic between Berri and Saint-Laurent streets, on de Maisonneuve Boulevard East. This measure was lifted on Tuesday.
The Société de transport de Montréal reports that a plan to inspect the structure of the vaults in all metro tunnels has been underway for the past few years.