Yonge North Subway Extension
Extending Line 1 subway service nearly 8 km north from Finch Station to Richmond Hill.- Projects & Programs
- Yonge North Subway Extension
- What We're Building
- Tunnel launch shaft and portal
Tunnel launch shaft
The launch shaft is temporary construction infrastructure that will serve as the starting point for two tunnel boring machines (TBMs) as they dig 6.3 kilometres of twin tunnels for the Yonge North Subway Extension.
Located south of the future Bridge Station, this deep, reinforced excavation is where the machines will be lowered into the ground before beginning their journey south to Finch Station, the current northern terminus of the Yonge branch of TTC Line 1.
As of July 2026, almost 70,000 cubic metres of soil has been removed from the launch shaft site and approximately 11,000 cubic metres of concrete and 860 tonnes of reinforcing steel has been used to form the walls and base of the structure. TBM assembly is now underway at the site.
During tunnelling, the launch shaft site will store construction equipment and materials needed for tunnelling, including the concrete segments that will be used to build the tunnel walls. A conveyor system will carry excavated soil and debris from the TBMs back to the shaft, where it will be collected and hauled away to be safely disposed.
Once tunnelling is complete, the machines will be lifted out of the ground near Finch Station, leaving behind the twin tunnels that will carry Line 1 subway service farther north into York Region.
Images
Aerial view of the tunnel launch site, showing the main launch shaft and supporting infrastructure being built for future tunnelling operations. (July 2026)
Aerial view of the tunnel launch site, with Highway 407 and the Richmond Hill skyline in the background. (July 2026)
One of two tunnel boring machines for the Yonge North Subway Extension at the manufacturer’s factory in Germany, ahead of its journey to Canada.
Construction timeline
Local construction
Click the icons on the map for the latest construction notices and other related information.
Tunnel portal
After tunnelling is complete, the launch shaft site will be converted into the tunnel portal — the permanent structure where Line 1 subway trains will enter and exit the underground tunnels.
The portal will be built on the same footprint as the launch shaft but is finished in a very different way. The temporary shaft infrastructure will be removed before permanent reinforced concrete foundations and walls are installed, followed by waterproofing and drainage systems. These will keep the tunnels dry and stable, and make sure subway trains move safely between the surface and tunnels.
Images
A tunnel portal under construction for the Eglinton Crosstown West Extension.
Community updates
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Get in touch
We're committed to keeping you informed and engaged every step of the way as we build the Yonge North Subway Extension.
Our team is here to answer your questions, address issues, and provide the information you need. Reach out to us any time at YongeSubwayExt@metrolinx.com or 416-202-7000.
You can also book a meeting with us online or at our community office in York Region.
