From tapping into seismic energy to mapping Toronto’s urban terrain – What’s next down the line for Ontario Line?

With the recent completion of one in a series of environmental reports, Metrolinx is another step closer to starting construction for the Ontario Line. Read more about the progress that’s in store – including one surprising tactic – as teams continue to flesh out plans for this critical project.

You can’t get to where you’re going in transit, without both a schedule as well as a map of the route. This feature is a bit of both when it comes to the next steps for the Ontario Line subway project – including the use of vehicles that dangle sensors, as occasionally a hammer is struck, to test the earth below.

The Ontario Line will add 15.6- kilometres of new subway service to Toronto’s growing rapid transit network and take people from one end of the city to the other in 30 minutes or less, with quick connections to dozens of bus, streetcar, subway and GO train routes along the way.

The project continues to gain momentum.

Getting shovels in the ground

This summer, the first shovels will break ground for the Ontario Line – specifically, the early works planned for Exhibition Station.

Image is of Exhibition station platform.
A GO train moves past Exhibition GO Station. The stop will be an important destination for the Ontario Line. (Metrolinx photo)

Ontario Line trains will run above ground at Exhibition Station, which currently accommodates GO, VIA and freight rail services. Since GO Expansion plans call for more GO train services at Exhibition Station, Metrolinx is carrying out early works for the Ontario Line in this area to ensure both projects are properly coordinated and completed quickly. Upgrades include a new station entrance, a new platform for the Ontario Line, an extension of existing passenger tunnels, and additional access to platforms

This ground breaking follows the completion of a dedicated environmental report for the work that was completed in February and will start once a construction team is chosen at the close of the ‘Early Works Tender in Market’ period this summer.

Keeping an ear to the ground

A person sits on a stool and looks at a monitor while in the middle of a street.
Against the backdrop of the city at night, an expert collects data that will help guide Ontario Line experts. Want to know more? The technician is reviewing the seismograph data received from the geophones. The seismograph measurement is triggered by the ground vibrations created by an energy source, in this case a sledgehammer on a metal plate. Time is then measured accurately until the ground vibrations have propagated through the ground and can be measured by geophones connected to the seismograph. The sledge hammer has a data cord attached to it. When the sledge hits the plate the seismograph starts measuring. The technician is watching the vibration being measured and indicating when and strike can be made. (Metrolinx photo)

People living near the route have likely already spotted teams at work surveying the landscape and occasionally drilling into the ground. Information gathered in the early stages on a project, before shovels hit the ground for construction, is a critical part of the project. A variety of investigations and surveys are used to collect information on things like street-level conditions, underground geology, and property boundaries.

Take geophysical surveying, for example, where a vehicle slowly moves down the road, with wires connected to sensors that dangle below, dragging on the surface. Occasionally, the vehicle stops, and a hammer is struck. This generates a signal that induces seismic energy waves through the ground. As the waves are reflected back to the sensors, recordings create a map of the underground – with the absolute minimum disruption of life at surface level.

That surveying wizardry is in full effect along the Ontario Line.

Topographic surveys are also underway, collecting information on existing objects on or near the surface, like buildings, streets, manholes, walkways, retaining walls, utility poles and trees, as well as differences in elevation.

All of these studies will continue along the Ontario Line route this year to inform ongoing environmental assessments and, ultimately, to help finalize design and construction plans before shovels hit the ground.

An expert looks at a device used on a street.
The Ontario Line is seeing countless important and telling tests being undertaken. (Metrolinx photo)

Eyes on the environment

Metrolinx officials say the line will fit comfortably into the neighbourhoods it will serve, respecting their important environmental features.

To do that, teams are conducting several detailed environmental assessments along the route, which will be summarized in comprehensive reports that detail the findings and recommend options to address any impacts. The assessments cover numerous topics, including noise and vibration, culture and heritage, and the natural environment. As with all environmental assessment reports, Metrolinx will consult the public on the findings and capture feedback in final reports that will be used to inform the design, construction and operation of the Ontario Line. Construction will only start after a related environmental assessment has been completed for the specific details of that work.

The assessment process started with the release of the draft Environmental Conditions Report in September 2020. It presented a series of studies that explored the existing environmental conditions along the route and its surrounding areas, along with an initial understanding of potential impacts and possible solutions. Several more detailed reports will be released in 2021 and 2022 to support sound planning, design and construction work for this critical transit project, including early works reports covering areas of the alignment where Ontario Line toiling will happen in the existing GO corridor, such as the Lakeshore East Joint Corridor.   

Keeping you informed and engaged

Image show the Ontario Line timeline.
Against the backdrop of the city at night, an expert collects data that will help guide Ontario Line experts. (Metrolinx photo)

The Ontario Line will be built with communities in mind and, in order to do that, Metrolinx continues to seek feedback and answer questions.

In early 2020, Metrolinx hosted in-person open houses before COVID-19 restrictions pushed most engagements to an online format. On the revamped Metrolinx Engage webpage, neighbourhood updates and environmental reports have been posted to keep the conversation going.

With more than 200,000 visits to online spaces, teams will be hosting an array of virtual engagements in 2021, including a round of online open houses starting this spring.

Metrolinx’s dedicated community relations team continues to be available by phone and email to listen to community feedback, provide the latest updates and answer questions. Visit here for all the latest project details and to sign up to receive updates as Metrolinx breaks new ground with this long-awaited transit project.

Story by Sara Wilbur, Metrolinx senior advisor, Subways.