Infrastructure maintenance

Infrastructure maintenance

Delivering quality service requires having equipment in good condition. With the support of governmental and municipal partners, we will invest massively in infrastructure maintenance over the next few years to support our vision of excellence in mobility.

Increasing our worksites represents a major operational challenge when it comes to maintaining the service we deliver to our customers. But even with more projects, we are able to operate our network normally while performing the work.

For our customers, this work will mean more reliable service and renovated, universally accessible stations with better lighting. It’s an ambitious but responsible initiative and a commitment to our future generations.

Here is what we're doing to ensure infrastructure sustainability and our projects currently underway.

What is a waterproofing membrane?

It is a device that protects the station from water infiltrations. The membrane covers the station’s underground roof and is therefore located underground.

Many stations' waterproofing membranes date back to the stations' initial construction and have reached the end of their useful life.

Replacing a waterproofing membrane requires excavating the ground above it. We dig one to four metres deep, depending on the locations. Since pedestrian passageways and underground métro stations span over larger areas than entrance buildings, excavation may be required on nearby streets. 


Water drainage work in vaulted ceilings

Water drainage work is used to channel water that infiltrates métro stations' vaulted ceilings. It requires installing gutters along the ceiling to drain the water and direct it into a pipe system, usually hidden behind wall finishes and below train platforms, and then into a pumping pit. Afterwards, the water is evacuated from the station and sent into the municipal sewage system.

This technique helps keep stations dry and avoids inconveniences related to water infiltrations. It also helps maintain the integrity of stations' architectural and electrical components and to keep them clean.

The arched ceilings above the tracks in the tunnel and the train platforms in the stations.

The gutters used are pipes installed along the joints of the vaulted ceilings. On average, there are 16 to 18 of these gutters per station, depending on the architecture. They are an important part of the drainage system and work by channeling the water away from the station.

It is mostly rainwater and water naturally occurring in the ground below Montréal. The City of Montréal’s sewage system also tends to leak. When it does, a certain amount of that water inevitably ends up in the métro.

We have tried several techniques to reduce inconveniences associated with water infiltrations. Instead of trying to waterproof the concrete ceilings, as we once did, today we prefer to channel the water. As water always finds a way, it’s better for us to find it first!

It all depends on how deep the station is and the type of soil around it. The stations most prone to this problem are those that are below the level of the St. Lawrence River.

For example, it appears that there was an underground stream running near Frontenac station a few hundred years ago. As a result, the ground around that station is particularly saturated. That explains why, if you listen closely, you sometimes hear water running behind the station’s walls. The water is being channeled away from the station by our drainage system.

Water infiltrations are normal in all types of underground facilities. They are not worrisome and will not alter the quality of the concrete.

In the long term, all métro stations will undergo this type of work.

Because this type of work produces a lot of dust and noise that could bother transit users, our bricklayers and plumbers work mostly late in the evening and at night. When they are at work, the trains must slow down prior to entering the station. For safety reasons, their speed is limited to 32 km/h instead of the usual 72 km/h.

Absolutely. Simply comply with the pictogram signs posted on the scaffolding directing passengers to either walk below it or between it and the wall. Avoid walking between the scaffolding and the edge of the platform, as it is a restricted zone where, for safety reasons, access is prohibited.

Major refurbishment of several escalators

With a constant view to improving your transit rides, we are set to refurbish 39 sets of escalators in the métro network. An escalator running upwards should be available at all times, whenever possible, in an effort to facilitate customers' transit experience while work is underway.

Some escalators inside Côte-Vertu, Jean-Talon, Outremont, Acadie, De Castelnau, Fabre, D’Iberville, Bonaventure and McGill stations will be refurbished. These escalators will undergo a major refurbish, using a combination of new and reconditioned spare parts. These escalators were chosen because of their 30-year average age.

Most of the escalators in the métro network have been replaced over the past few years. However, there are still about sixty escalators that date back to the métro’s expansion in the 70s and 80s. When they break down, repairing them is unfortunately rather complicated. Spare parts are harder to obtain, causing further delays.

Start of work: August 2021
Type of work: Replacement of the escalator
Alternative route: An escalator will still run upwards
Service scheduled to resume : December, 31 2021

Start of work: June 2021
Type of work: Replacement of the escalator
Alternative route: An escalator will still run upwards
Service scheduled to resume : December, 1, 2021

Start of work: November, 23, 2021
Type of work: Replacement of the escalator
Alternative route: An escalator will still run upwards
Service scheduled to resume : February 28, 2022

Start of work: July 26, 2021
Type of work: Staircase renovations
Escalator: Linking the street level to the fare booth level
Alternative route: The other escalator will still run upwards
Service scheduled to resume : December, 31 2021


Incidents involving improper use are the main reason why escalators are out of service. For example, items are dropped and get stuck in the stairs or people fall down, requiring the escalators be stopped. Other frequent causes are people sitting on the moving handrail or pressing the emergency stop button for no good reason.

If an incident has little or no repercussion on an escalator, it can be started up again quickly by a station employee. If there is a chance, however, that the incident has damaged or otherwise compromised the escalator’s integrity, the equipment must be shut down until specialized mechanics can inspect it and perform any necessary repairs or adjustments before putting it back into service.


An impressive amount of escalators

The STM’s network has 296 escalators. They are used heavily due to the 250 million passenger trips made on the métro each year. In addition several of them are located next to entryways, exposing them to harsh weather conditions and temperature changes.

Work is carried out thanks to funding provided by the Ministère des Transports du Québec.

Mechanical ventilation stations

As part of our program to maintain métro infrastructure, we are building several mechanical ventilation stations in the network.

A mechanical ventilation station is a large infrastructure located between two métro stations that is equipped with two powerful fans designed to extract hot air from the métro network through inlets fitted with air vents. Ventilation stations built for the original métro network extract around 60,000 cubic feet of air per minute, while the new ventilation systems extract around 240,000 cubic feet per minute. Huge noise suppressors mitigate the noise from these fans to ensure quiet for residents living close to a ventilation station.

  1. Comfort ventilation: Regulates the ambient temperature and supplies fresh air for transit users by exchanging air from the outside with air inside the métro network.
  2. Night-time ventilation: Ensures a supply of fresh air for night workers carrying out routine maintenance.
  3. Emergency ventilation: In the event of an incident, controls smoke and provides a safe evacuation route for passengers via the nearest métro station and ensures unobstructed access for emergency first responders.

No. Once the ventilation station is operational, the noise it emits will comply with municipal by-laws. The fans are installed below ground and equipped with powerful noise suppressors. The noise level outside the building will not exceed 50 decibels, even when the ventilation station is operating at full capacity, which is unusual. The station’s noise level will be comparable to that of a household dishwasher. In fact, it will be so low that normal conversation or ambient noise could easily cover it.


No. Essentially, a mechanical ventilation station exchanges the air inside the métro that transit users breath with outside air, ensuring a constant supply of fresh air.

No. There are no contaminants in a mechanical ventilation station. Rainwater or snow falling into the ventilation shaft will be collected by the métro’s water-pumping system and released into the municipal sewage system, which is the current process throughout the métro network.

No. A mechanical ventilation station does not have the necessary infrastructure to be transformed into a métro station. No such plans have been made in this sense.

This work is necessary to ensure the longevity of the métro network’s power supply system, as existing equipment has reached the end of its useful life. More specifically, the project involves the construction of a new building, at the same location where the Lionel-Groulx garage stands today, between Greene Avenue and Rose-de-Lima Street. A public consultation about the project was held in 2018.

Current Lionel-Groulx garage seen from Greene Avenue.

An electrical substation houses all the equipment needed to distribute electrical power to the métro network. There are seven of these substations located throughout the STM’s métro network.

The existing electrical substation was built in 1978. The equipment it holds has reached the end of its service life and must be replaced.


Refurbishing an electrical substation presents a specific challenge, as the power supply to the métro cannot be cut off while the work is underway. The equipment must remain in operation to keep the métro running. For this reason, we need to build a new electrical substation and transfer the electrical loads from the old electrical substation to the new one without disrupting métro service.

To lessen the impact caused by the construction of the new building, we will build it where the Lionel-Groulx garage currently sits, between Greene Avenue and Rose-de-Lima Street.

Refurbishing the electrical substation calls for the following work:

  • Demolition of the existing garage
  • Construction of a new building to house the garage and new electrical equipment  
  • Construction of underground ducts below Greene Avenue

Other related work will be needed to ensure the longevity of underground infrastructure:

  • Replacement of a waterproofing membrane to protect against water infiltrations between the station’s main entrance building and the garage.  

Finally, all landscaping and design work affected by the construction zone will be entirely rehabilitated once the project is completed.

    • We will ensure that mitigation measures are implemented to lessen the impact of the work on the neighbourhood, such as monitoring noise levels,  spraying water to prevent dust dispersal during the demolition and excavation phases, and providing mandatory truck washing stations.
    • A communication plan consisting of various communication tools will keep nearby residents and customers informed throughout the project.
    • A traffic plan for pedestrians, cyclists, motorists and trucks will be implemented to keep traffic moving smoothly in the sector.

    This work is made possible through funding from the Ministère des Transports du Québec.

    Over the next few years, some twenty auxiliary structures, located throughout the métro network, are slated to undergo major refurbishment work.

    It’s a service building located between two métro stations that houses a variety of mechanical and electrical equipment needed for métro operations, such as  ventilation, power supply and pumping to remove runoff water. All in all, the métro network has 119 such buildings that, understandably, are not open or accessible to the public.

    Refurbishment work will mainly be carried out on the buildings’ structural, mechanical and electrical components. These renovations will serve to extend the service life of the buildings by 25 years.

    The auxiliary structures that will be refurbished have been in use ever since the métro line sections they serve went into operation, so they have reached the end of their service life.

    The work will not impact your trips or the service service on the various métro lines. The renovations will ensure, however, that all the equipment supporting métro operations will run properly for many years to come!

    This work is made possible through funding from the Ministère des Transports du Québec.

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