Ontario Construction News staff writer
Excavation has been completed for the tunnel launch shaft of the Yonge North Subway Extension, marking a key construction milestone as Ontario advances the subway expansion into York Region.
Crews have removed about 70,000 cubic metres of soil to prepare the site where two tunnel boring machines will begin excavating the project’s twin 6.3-kilometre tunnels. The launch shaft extends 10 metres below ground and required about 11,000 cubic metres of concrete and 860 tonnes of reinforcing steel.
“TRACCS recognizes the completion of excavation at the Yonge North Subway Extension’s tunnel launch shaft as a major milestone that brings this transformative transit project another step closer to reality,” said Mark Salsberg, chairperson for Transit Rail Association for Canadian Contractors, Maintainers, Operators and Standards (TRACCS). “As the project advances toward tunnelling, it continues to demonstrate the economic and community benefits of investing in public transit, supporting 4,300 jobs annually, connecting nearly 23,000 jobs to reliable transit and helping build a more sustainable and prosperous Ontario.”
The extension will extend the TTC’s Line 1 subway almost eight kilometres north from Finch Station into Markham and Richmond Hill, adding five new stations at Steeles, Clark, Royal Orchard, Bridge and High Tech.
With excavation complete, the next major phase will see the tunnel boring machines begin construction of the underground tunnels. The province has also issued a request for proposals to pre-qualified teams to design and build the extension’s stations, trackwork and support systems. Utility relocation work is already underway to prepare for future station construction.
Construction of the extension supports about 4,300 jobs annually and is expected to generate more than $3.6 billion in economic benefits. The province also says the project will reduce personal vehicle travel by about 7,700 kilometres during rush hour each day and cut greenhouse gas emissions by more than 4,800 tonnes annually.
“Completing excavation at the Yonge North Subway Extension’s tunnel launch shaft and inviting qualified teams to bid on the project’s final major contract reflect a growing momentum building behind this extension,” said Michael Lindsay, president and CEO of Metrolinx. “As we get ready to receive the tunnel boring machines that will carve out the extension’s twin tunnels, we’re looking forward to starting the next phase of building this important project.”
A new Bridge Station will serve as a regional transit hub, providing connections to GO Transit rail and bus services, as well as York Region and local bus routes.
The federal government is contributing $2.24 billion toward the project. In September 2024, Ontario and York Region signed an agreement in principle establishing the framework for project delivery, funding and operations.
The project is part of Ontario’s $70-billion transit expansion program, which also includes the Ontario Line, Scarborough Subway Extension and Eglinton Crosstown West Extension. The province says the broader capital plan includes transit-oriented communities around future stations, with plans for more than 40,000 new homes near the High Tech and Bridge stations.
