Montreal blue line extension starts excavation with giant tunnel boring machine

Construction of Montreal’s long-awaited blue line metro extension is moving into the underground phase.

A massive 9.7-metre wide tunnel boring machine was unveiled Monday. It will dig through rock to create the tunnel from the future Vertières station to the Anjou station — a stretch of 4.6 kilometres.

While officials say similar machines have been used extensively in Europe, this is the first time one will be used to build a Montreal metro tunnel.

“It’s a historical moment today. We’re really thrilled to be here today,” said Aref Salem, chairman of the board of directors of the STM.

A massive cutting wheel will soon begin digging through the earth, carving out the tunnels.

“It has, I guess you can call them teeth,” said Maha Clour, the executive project director of the STM Blue Line Project. “So once it turns, it grinds the rocks.”

Once the machine breaks apart the rocks, it sends them back through the inside of the drill to be deposited at the Vertières station construction site.

It’s being described as an “engineering feat rarely seen” in the province since it both excavates and finishes the tunnel in a single pass.

The machine is expected to excavate the rock at an average rate of 10 to 15 metres per day. Tunnelling won’t stop until the work is complete — at some point in 2028.

The tunnel boring machine arrived in Quebec in October and needed to be assembled. The components were recently successfully lowered to approximately 20 metres below ground level.

“Which means that we won’t ever hear it or even feel it once it’s travelling under Jean-Talon East Street,” Clour explained.

Once the tunnelling is done, the machine will be returned to German manufacturer Herrenknecht.

A handful of government officials were on hand for the unveiling of the machinery Monday, including Salem, Quebec Minister of Transport and Sustainable Mobility Jonatan Julien, and Quebec Minister responsible for the Metropolis and the Montreal region Chantal Rouleau.

They say Montreal’s East End has waited roughly 40 years for the project to move forward.

After being discussed for decades, the project was greenlit in 2018 and construction officially began in 2024.

“We are in time, in budget. It’s very important for us,” Rouleau said.

The entire blue line extension project, which has a price tag of $7.6 billion, won’t be complete before 2031. It will add five stations to the blue line, with names paying tribute to women and communities that have marked Montreal’s history.

“It’s a game-changer for the east of Montreal,” Salem said. “We’re adding five stations. We’re on time, on budget so far.”