Next steps for the Davenport Diamond Guideway project
With the temporary diversion track up and running, construction can begin on the elevated guideway.
Sep 8, 2020
As GO trains pass through the section between Bloor Street and Davenport Road, Barrie line customers might not notice they are travelling on track that has been shifted to the side.
Since May 2020, construction on the Davenport Diamond project has been entirely focused on a temporary diversion track.
“Getting the diversion track safely up and running was the first major milestone for the Davenport Diamond project. It signals the start of construction on the elevated guideway, making it a significant achievement for all,” said Kent Barber, Metrolinx project lead.
Most of the diversion track was built in the months leading up to the September long weekend, while trains ran on the main Barrie line. The last few pieces of the puzzle, however, had to be carried out while no trains were in service.
A major track closure on the Barrie GO line over the September long weekend allowed crews to make the necessary connections between the new diversion track, the existing main line track and the intersecting CP Rail freight tracks.
At the two far ends, crews connected the diversion track to the main line. This is known as a track tie-in, and one connection took place near Bloor Street and the other near Davenport Road.
Crews cut the existing track, pulled it over to line up with the diversion track, and welded the two together. At Bloor, about 80 metres of main line track were pulled over, compared to the 100 metres at Davenport to account for the curve in the track.
North of Dupont Street, where the Barrie GO line meets the CP Rail freight tracks, more connections were made. As the GO track (i.e. the diversion track) now intersects with the CP tracks at a different point, a temporary diamond that aligns with the diversion track was installed at this new intersection. The existing diamond was decommissioned and removed.
Before the diversion track was built, a couple of major works took place. First was the construction of a shoring wall northeast of the diamond to support the diversion track structure next to an open excavation at the neighbouring development. And second was the relocation of the northeast signal arm at Wallace Avenue to align with the diversion track and maintain safety at this crossing.
The diversion track was built in stages, beginning with clearing and grubbing of vegetation to make room for the new track. Next, grading activities, including laying down sub-ballast, created a strong, even ground. Once a solid foundation was attained, pre-ballast was laid, followed by track and ties, and finished off with ballast.
At 1.7 kilometres long, the diversion track runs from just north of Bloor Street to just north of Davenport Road.
“The diversion track is the result of a lot of hard work and detailed planning by all parties. Now that it’s successfully in operation, we can shift our focus to the heart of this project, the elevated guideway, and we’re really excited to get started on it,” said Mathew Hanna, Design-Build Director for Graham Commuter Rail Solutions.
With the diversion track up and running, the portion of existing main line no longer in use will be decommissioned and removed to allow construction to begin on the elevated guideway.
by Teresa Ko Metrolinx communications senior advisor