First Tunnel Boring Machine Arrives for Yonge North Subway Extension

This report by Farshad Fazaeli is based on information published by Metrolinx.

A significant delivery for the Yonge North Subway Extension occurred on October 26, with the arrival of the first of two tunnel boring machines (TBMs). This TBM is designated to dig one of the twin 6.3-kilometre tunnels that are part of the extension. The machine has been delivered to the tunnel launch shaft site located in York Region.

The TBM features a prominent red maple leaf emblem, and its large circular cutterhead is designed to rotate and carve out one of the new subway tunnels. This process will begin once the machine is fully assembled and prepared for operation. Currently, work to assemble this first TBM is underway. A crane is being utilized to lower the machine's various pieces into the launch shaft, where the complete assembly will take place. This marks a crucial step, bringing the Yonge North Subway Extension closer to the commencement of tunneling activities. The second TBM, when it arrives, will undergo a similar assembly process.

In parallel with the TBM assembly, crews are actively preparing the launch shaft site for future tunneling operations. This preparation involves the installation of essential equipment and support systems that the TBMs will require once they begin their excavation work. Both tunnel boring machines are planned to initiate their underground journey from this launch shaft.

The Yonge North Subway Extension project aims to extend the TTC Line 1 subway service approximately eight kilometers further north. This expansion will establish rapid transit connections from downtown Toronto to various areas including Vaughan, Markham, and Richmond Hill. The extension is designed to include five new stations, which will be situated at Steeles, Clark, Royal Orchard, Bridge, and High Tech.

Once assembled, the two TBMs will tunnel southward from the launch shaft. Each machine will be responsible for digging one of the twin tunnels. These tunnels will ultimately connect the new subway extension to the existing Line 1 service at Finch Station. The Yonge North Subway Extension is projected to add over 94,000 transit rides to the network daily. This is expected to result in reduced travel times, potentially cutting them by up to 22 minutes, and is also anticipated to decrease greenhouse gas emissions by more than 4,800 tonnes annually.

According to Metrolinx. Source: Metrolinx