A major piece of equipment essential to digging the new Montreal metro blue line extension tunnel has fully arrived in Montreal. It’s called a tunnel boring machine and, once assembled, will measure 10 metres wide and 140 metres long. A specialized piece called the cutter head will dig through the rock to create a tunnel and send the debris up conveyor belts to the future Vertieres metro station to be trucked away. “It’s basically building the backbone of the blue line extension,” said project chief Maha Clour, pointing out that crews have reached the bottom of their excavation at two of the five future metro sites and now will need to tunnel horizontally to link them all. In the spring, the tunneller will be lowered into the bottom of the site to begin its 4.5-kilometre journey across Saint-Leonard and Anjou. “It’s going to be rolling between 18 to 40 metres in depth,” said Clour. “It’s one of the great aspects of a tunnel boring machine is that it’s very little perceivable from the surface.” Assembling the massive tool is a challenge for workers, though. “We have pieces up to almost 200 tons on site that we need to handle,” said project manager Vincent Murphy. “That’s why we have a 650-ton crane in order to be able to lower these pieces down into the excavation site once it’s assembled.” Currently, there are nearly 100 pieces that were shipped from Germany and need to be put together like a puzzle. The equipment was brought to the Port of Montreal, then taken by truck to the site along Jean Talon East in the middle of the night to not disrupt traffic. “We’re building in a very dense urban area and we’re very conscious about it,” added Clour. “We’ve got walls that ensure noise level control. We’ve got dust control, we’ve got vibration control.” The tunnel boring project costs about $1.1 billion of the total $7.6 billion blue line extension. The boring machine can travel about 10-15 metres per day, meaning it will take about two years to finish the job. The first metro cars are expected to be running in 2031. “We’re on budget, on scope, on time, and we’re very proud of what’s going on,” said Clour.
