Ontario’s Metrolinx is marking another important milestone for its three-stop Scarborough Subway Extension as the project’s 11.9m diameter Herrenknecht TBM, Diggy Scardust, is being prepared for launch on its 7.8km journey from Sheppard Avenue and McCowan Road. Crews on site have completed building the approximately 28m deep launch shaft and parts of the TBM are currently being lowered into the shaft.
The main shield was the first piece to be lowered and will be followed by the tail can and then the cutterhead. Once assembled, Diggy Stardust will be the biggest TBM used for a transit project in Canada to date.
When tunnelling begins, Diggy Scardust will travel south, going about 10m a day, erecting the 10.7m diameter segmental lining towards Midland Avenue and Eglinton Avenue, where crews will eventually lift it out of the ground.
Soil and rocks will be removed by a screw conveyor and transported back to the launch shaft site via belt conveyor before removal from site and disposal.
In May 2021, Infrastructure Ontario and Metrolinx awarded the $757.1M contract to Strabag to design, build and finance the tunnel for the Scarborough Subway Extension.
The Scarborough Subway Extension Advance Tunnel scope of work includes:
- Tunnelling works for the 7.8km subway extension, from Kennedy Station to McCowan Road/Sheppard Avenue.
- Design and construction of launch and extraction shafts, tunnels, as well as headwalls for emergency exit buildings and stations.
- Supplying the TBM and installing segmental precast concrete tunnel liners.
- Activities necessary to build the tunnel (e.g. utility relocations, supports for shaft and headwalls, temporary power supply, lighting, ventilation, and drainage).
The Strabag team includes:
- Applicant Lead: Strabag AG
- Construction Team: Strabag Inc.
- Design Team: Arup Canada Inc., Brian Isherwood & Associates Ltd.
- Financial Advisor: Strabag Inc
The proposed Scarborough Subway Extension will bring the TTC’s Line 2 subway service nearly 8km farther into Scarborough. It will extend from Kennedy Station to Sheppard Avenue and McCowan Road, providing quick and seamless transit for those heading into and out of the downtown core and those travelling within Scarborough. The extension will replace Line 3 (the Scarborough RT), helping to reduce travel times and improve access to jobs, schools and other key destinations throughout the city.
Metrolinx and Infrastructure Ontario are working together to deliver the Scarborough Subway Extension, which is estimated to be complete by 2029-30.