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Image of rails Réseau express métropolitain REM

On track with the REM

Project progress
Published on

Installing the rails is a prerequisite for running trains, the equivalent of paving the highway for cars. Although they may at first appear simple, rails have a surprising level of complexity when you take the time to look at them. 


More than just steel rods

Alignments and adjustments with switches and crossings are a real challenge for railway engineers.

Image of rails installed but not fixed on the route of the Réseau express métropolitain REM In this picture, it looks like the rails are installed and the job is done. Make no mistake, they’re in place, but there is still a lot of painstaking—and important—work to be done: alignment and final adjustment.

Rails that react to the vagaries of the weather

The warmer it is, the more the rails will expand, while the colder it is, the more they will contract. When it is finally the time to fasten the rails, they must be secured to the ties at a neutral temperature—a process called “destressing the tracks.”


Installing the rails on the Samuel De Champlain Bridge

Rails are installed on the central deck of the Samuel De Champlain Bridge. The rails must adapt to the movements of the bridge structure, i.e. the expansion or contraction of the bridge spans. How is this done? The track expansion joints allow the rails to move as the bridge moves. The joints installed on the deck are particularly imposing: they can expand up to1,000 millimetres, instead of the usual 200 to 300 millimetres.

Did you know?

Affixing the rails directly to the bridge is extremely complicated because of the temperature that affects the rail-structure interaction. In order to deliver the South Shore segment this year, crews had to work on the tracks during the 2021–2022 winter period. Installing the track expansion joints on the Samuel De Champlain Bridge in the winter was a real engineering and logistical challenge. It also required workers to be extremely resilient, as they had to contend with a very cold winter in which the mercury dipped to -20°C.

Image of the rails on the Samuel-De Champlain Bridge Close-up of the rails on the Samuel-De Champlain Bridge

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What is the status of the REM project?

  • South Shore: 17.3 km of double track* 
  • Deux-Montagnes: 4.8 km of double track* 
  • Anse-à-l’Orme: 10.3 km of double track* 

*Double track including ballast, ties, and fasteners

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Types of rails

The type of rail installation is chosen based on the conditions and constraints of each sector. 

Ballasted tracks are installed on a surface called sub-ballast. The ballast can be made of stones or gravel. Rather than being set in concrete or directly attached, this type of installation holds the rail system in place with the help of ballast. This type of rail can be seen on existing railroad rights-of-way. For example, this is the type of rail used at several locations on the Deux-Montagnes branch.

Image of ballasted tracks for the REM Example of ballasted tracks near the Du Ruisseau station

Duo-block tracks are installed using a construction method known as top down. The already attached rails are installed on a tie (sometimes called a sleeper) to keep them parallel. Once the rails are aligned in their final position and installed on the structure, the entire assembly is poured into a concrete sidewalk. This method is called top down because it starts with the fixing of the rails and ends with the pouring of concrete.

Image of duo-block tracks for the REM Example of duo-block tracks in the Griffintown area

Direct fixation tracks are installed, as the name suggests, directly to the concrete structure. First the support plate is installed, then the rails and lastly, the rails are adjusted.

Image of direct fixation tracks for the REM Example of direct fixation tracks between Fairview-Pointe-Claire and Kirkland stations

Go futher

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Rails: A field you’re interested in? 

There’s still a lot of work to be done before the REM is commissioned. Nouvlr, the consortium responsible for the construction, is in full recruiting mode.

Visit their career site or email them your application directly: [email protected]