Ontario Line South

Background

VINCI Construction Grands Projets (50%) and Ferrovial Construction (50%) have joined forces to create Ontario Transit Group.  The joint venture has been selected to deliver the Ontario Line Southern Civils, Stations and Tunnel contract, which is part of the future Ontario Line subway.

The Ontario Line Southern Civils, Stations and Tunnel contract covers the financing, design, and construction of the civil engineering (excluding rail systems) for a 2 x 6 km twin-tube tunnel, as well as the construction of 7 new stations. The work is expected to be completed in 2030.

This is the second major design-build-finance project that VINCI Construction Grands Projets is undertaking in Ontario, in parallel with the extension of the Confederation Line to Ottawa, where construction of 27 km of new track for 16 stations and associated works is currently underway.

Technical overview

The twin-tube tunnel is expected to be built using two earth-pressure tunnel boring machines (TBMs), making complete west-to-east blasts through six underground stations. Exhibition station, the western-most station, will be an interchange station connecting with existing rail lines, including the Greater Toronto Area commuter rail system, GO Transit.

The other six stations will initially be built using the bottom-up method, with excavation from top to bottom and structural construction from bottom to top. Five of these stations include an underground “cavern” section, excavated using the Sequential Excavation Method (SEM). The structure of these caverns will be completed before the passage of the TBMs.

Given that the new subway line will run through Toronto’s densely populated downtown core, crews will have to implement construction methods optimized for a confined space. Strict noise and vibration constraints require the use of acoustic shelters integrated into the station foundations in some areas, as well as the installation of appropriate screens around the periphery of the sites.  There is also significant heritage preservation included in station design, which requires specialized crews and work to secure heritage buildings prior to major construction.

Impact

Once complete, the Ontario Line is expected to create significant benefit to the City of Toronto.  Here are a few of the expected benefits :

– End-to-end journey time: 30 minutes or less

– Connections to other transit options: Over 40, including:

• Connections to Lakeshore West, Lakeshore East, and Stouffville GO train services
• Connections to the TTC’s Line 1 and Line 2 subways
• Connection to Line 5 (Eglinton Crosstown LRT)
• Connections to streetcar lines at 10 Ontario Line stations
• Connections to bus services at 12 Ontario Line stations –

– Ridership: 388,000 daily boardings

– Frequency: As frequent as every 90 seconds during rush hour

– Improved access to transit: 227,500 more people within walking distance to transit

– Improved access to jobs: Up to 47,000 more jobs accessible in 45 minutes or less, on average

– For lower-income residents: Up to 57,000 more jobs accessible in 45 minutes or less

– Reductions in rush hour crowding:

• Up to 22 per cent at Bloor/Yonge Station, or 14,000 fewer people, during the busiest hour
• Up to 16 per cent at Eglinton Station, or 5,000 fewer people, during the busiest hour
• Up to 14 per cent at Union Station, or 14,000 fewer people, during the busiest hour

– Daily reductions in traffic congestion: 28,000 fewer car trips every day

– Yearly reductions in fuel consumption: 7.2 million litres