Early construction work on the Scarborough subway extension has been underway for the past year, but officials say tunneling on the 7.8-kilometre expansion of TTC Line 2 is now underway.
Transportation Minister Caroline Mulroney's office confirmed that the tunnel boring machine began its southbound journey from Sheppard Avenue and McCowan Road on Tuesday morning.
Staff at Metrolinx, the provincial transit agency overseeing the project, said the machine, roughly the length of three GO Transit train cars that will create a tunnel with a diameter the width of more than three TTC subway cars, will move about 10 meters a day. The entire journey is likely to take a little more than two years to complete.
As it proceeds south along McCowan and Danforth roads before turning west under Eglinton Avenue East, soil and rock will be continuously removed via a conveyor belt as the tunnel liners are placed.
The tunnel boring machine will eventually be removed at Midland Avenue and Eglinton Avenue East. Construction crews have already begun work to move Eglinton Avenue East north of where it currently meets Midland Avenue, as it will be necessary to remove the machine from where the current roadway is located.
The extension is estimated to open in 2030 and both Mulroney's office and Metrolinx staff said it is estimated that more than 100,000 people will pass through the three new stations.