Metrolinx has announced that construction is now underway for the Yonge North Subway Extension, which will aim to bring TTC Line 1 subway services approximately 8km further north with five new stations.
In the York region, excavation of the tunnel launch shaft is now complete, and work has begun to prepare the site for future tunnel works.
Located just south of the Langstaff GO Station on the west side of the existing railway tracks, the launch shaft will soon act as the starting point for a set of twin tunnel boring machines (TBMs), which will begin digging the underground portion of the extension once situated.
Once on the move, the TBMs will excavate 6.3km of twin tunnels in an effort to connect the extension to the existing Line 1 service at Finch Station.
In order to accommodate the work, reinforced concrete foundations were installed deep underground to create outer walls for the launch shaft, as well as support the surrounding ground during excavation.
Elsewhere on site, work has begun to prepare areas where excavated soil and rock from future tunnelling will be stored before being hauled away, and whilst construction work has begun, an important milestone has also been reached in the search for teams to design and build the extension’s five new stations, as well as tracks, support systems, and other infrastructure needed to bring TTC Line 1 service farther north.
Thus far, teams that qualified during an earlier request for qualifications processes have officially been invited to submit proposals to deliver the work.
Once completed, the extension of Line 1 is expected to carry over 94,000 riders a day, reduce travel times by up to 22 minutes and cut greenhouse gas emissions by more than 4,800 tonnes annually.
