Process initiated to use a tunnel boring machine for the Blue line extension

The use of a tunnel boring machine (TBM) is planned for most of the excavation work. This specialized piece of equipment will also line the metro tunnel with pre-made concrete segments or voussoirs.

“This will be the first use of a TBM in the long history of the STM,” says Marie-Claude Léonard, Interim CEO of the STM. “It will allow us to speed up the excavation process and will help us to build high-quality infrastructure as we extend the Blue line of the Montréal métro.”

“The publication of the pre-qualification notice is great news for the STM and represents another step toward the execution phase of this structuring project for the STM, its clients and citizens of the East.” added Éric- Alan Caldwell, Chair of the STM Board of Directors.

Multiple advantages

The TBM method of tunnel excavation and construction is faster than traditional methods, which will help to keep the project on schedule. Perfect for a rocky subsurface such as the blue line extension, the TBM also has the advantage of being less disruptive to neighbourhoods on the surface, as it causes less noise and vibration.

The specialized machine will also provide lasting results and more waterproof tunnel walls, due to the use of pre-made concrete rings that will be installed along the way as the TBM bores through the ground. From an environmental perspective, the TBM has the added advantage of operating on electrical power, thus less polluting.

The TBM used for the blue line extension excavation work should be able to move at an estimated rate of 13 to 15 metres a day, on average.

Help name the TBM
The public will be invited to help the STM choose a name for the TBM. The details of the naming process will be unveiled after the contract has been awarded.

Technical image of a TBM