an LRT going under a bridge.

Energizing the Hurontario LRT using traction power substations

The Hurontario LRT will feature electric light rail vehicles producing near zero emissions.

Aug 9, 2021

All of the region’s light rail transit (LRT) lines will run on electricity and the Hurontario LRT is no exception.

But the Hurontario LRT can’t just plug into a regular power outlet. It needs some special infrastructure to make it come to life.

That’s where traction power substations (TPSS) come into play.

TPSS’s are small steel buildings, similar in size to a shipping container, and are used to convert alternating current (AC) electricity from the local power supply to direct current (DC) electricity to generate consistent power to operate the light rail vehicles.

an artists rendering of a traction power substation

Once complete, the TPSS units will be similar to the size of a small shipping container. (Metrolinx image)

They are regularly used for light rail transit projects and can be found in neighbourhoods throughout North America. For instance, they are used in Toronto to power the TTC lines.

The Hurontario LRT TPSS’s will be constructed to comply with Health Canada’s standards, which means the inclusion of many features which are designed with safety in mind:

  • All electrical equipment in a TPSS is enclosed within a locked building, which provides security and absorbs sound
  • Unlike typical utility transformers that use oil for electrical insulation, the power transformer in a TPSS is a “dry type”, which means that it will not leak or catch fire
  • All TPSSs receive regular site maintenance visits to ensure everything is operating properly

How does the installation work?

The first step is the site preparation which includes environmental measures such as erosion and sediment control fencing to protect water quality in nearby bodies of water, and temporary fencing to keep the site secure.  

The site will also be made level, making it ready for the construction phase.

After the site preparation, construction crews will then install the duct banks that will connect the TPSS to the rail line.

The Hurontario LRT will feature electric light rail vehicles producing near zero emissions.

Construction crews work on site preparation for one of the TPSS units along the Hurontario LRT route. (Metrolinx photo).

Following installation of the underground duct banks, construction crews will build the concrete slab which will anchor the prefabricated TPSS units within the site.

After the prefabricated TPSS unit has been installed and secured on site, crews will clean up the site and install the power cables. The power cables not only provide the LRT with electricity, the also help monitor performance and maintenance issues.

Site restoration work includes landscaping (planting trees, shrubs, and laying sod), hardscaping (creating a turf stone driveway, perimeter curb, asphalt driveway and sidewalk rebuild) and TPSS unit architectural finishes, like cladding.

The construction for the TPSS sites will begin towards the end of the year and are anticipated to be done by fall of 2024.

Continue to watch the Hurontario LRT project progress by following the project on Twitter here.

by Erika D’Urbano Communications senior advisor