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 the 6.3-kilometre journey of the future tunnel boring machines (TBMs).
It is a deep, reinforced excavation where the two TBMs will be assembled and lowered into the ground to start tunnelling.
Located south of the future Bridge Station, the launch shaft will allow the tunnel boring machines to begin their journey south to Finch Station, where they will be lifted out of the ground and retired once tunnelling is complete.
Almost 70,000 cubic metres of soil has been removed from the launch shaft site (as of July 2026) 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.
Work is now underway to prepare the site for the arrival, assembly and testing of the two tunnel boring machines. Once ready, the machines will be lowered into the launch shaft to begin digging the twin tunnels that will carry extended TTC Line 1 subway service farther north.
The launch shaft site will be used to store construction equipment and materials needed for tunnelling, including the concrete segments that will be used to build the tunnel walls. Excavated soil and debris from the tunnel boring machines will travel along a conveyor system back to the shaft, where it will be collected and hauled away to be safely disposed.
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
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.
