By rosebell
Two TBMs, Libby and Corkie, have launched on a 6km twin-bore drive beneath downtown Toronto for the Ontario Line, marking the first new subway tunnelling in the city centre in more than 60 years.
The machines are advancing from a launch shaft just east of Exhibition Station, excavating tunnels at depths of around 40m to a retrieval site west of the Don River. TBM Libby is leading the drive, with Corkie to follow on the parallel bore. Screenshot 2026 04 22 at 11.26.03
The TBMs—named after Liberty Village and Corktown—will pass through six underground station caverns along the downtown alignment: King West, Chinatown, Osgoode, Queen, Moss Park and Distillery District. Interchange with existing TTC Line 1 services will be provided at Osgoode and Queen stations.
The works are being delivered by Ontario Transit Group (OTG), a consortium of Ferrovial Construction, Vinci Construction Grands Projets and Janin Atlas, under a progressive design-build contract for project owner Metrolinx. The Ontario Line is one of the largest transit investments in Canada, with an overall project value of approximately CAD 10.9bn.
The TBMs have been selected to manage Toronto’s mixed ground conditions, including glacial tills and variable groundwater. Each machine will install precast segmental linings as tunnelling progresses.
Both TBMs will break through pre-excavated station boxes, where excavation is already complete at King West, Moss Park and Distillery District, and nearing completion at Chinatown.
On completion of tunnelling, the Exhibition launch shaft will be converted into a portal structure, enabling trains to transition between surface and underground operation. A corresponding portal is under construction at Don Yard, where both machines will be received.
The downtown alignment represents the first of two bored sections on the Ontario Line. A second tunneled section will run largely beneath Pape Avenue, from north of Gerrard Station to near the Don Valley Parkway. Construction of the second launch shaft at Gerrard and Carlaw began in 2025.
Once complete, the Ontario Line is expected to carry around 400,000 passengers per day between Exhibition Place and Line 5 Eglinton at Don Mills Road, with more than 40 connections to the wider transit network.
