Tunnel boring for Broadway Subway reaches full completion

Tunnel boring machine Elsie breaking through at South Granville Station on the Broadway Subway on February 8, 2024. (Government of BC)

The project to build the Broadway Subway has reached its largest milestone yet: the full completion of the entire tunnel boring process.

Last Friday, April 26, the tunnel boring machine named Elsie broke through the Cypress Street wall at the eastern end of the Arbutus Station pit, marking the end of her journey in building the subway’s eastbound tunnel.

This follows Phyllis’s initial arrival at Cypress Street on March 20. Phyllis is the tunnel boring machine for the westbound tunnel.

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It took Phyllis 50 days to dig the four-block segment from Granville Street — the western wall of South Granville Station — to Cypress Street, while her sister Elsie completed the same segment in 52 days.

However, the final breakthroughs of Phyllis and Elsie at Cypress Street were muted — literally. Instead of the usual dramatic entrance view of concrete cracking and falling apart to reveal the machine’s cutter head, the breakthroughs at Cypress Street have looked a little different. According to the project office, due to softer ground conditions in the Arbutus Station area, both tunnel boring machines broke through into a specialized pressure chamber that collects the rubble.

broadway subway elsie tunnel boring machine arbutus station april 26 2024

Tunnel boring machine Elsie breaking through at the Cypress Street wall of Arbutus Station on April 26, 2024. (Government of BC)

broadway subway phyllis tunnel boring machine pressure chamber

Tunnel boring machine Phyllis breaking through at the Cypress Street wall of Arbutus Station on March 20, 2024. (Government of BC)

broadway subway pressure chamber tunnel boring breakthroughs

Special pressurized chambers for the final breakthroughs of the tunnel boring machines at Arbutus Station. (Government of BC)

The process of disassembling and lifting Elsie from the extraction area at Cypress Street is now underway, which has already been accomplished for Phyllis.

Both tunnel boring machines first began their 5 km-long journey with a staggered launch weeks apart in Fall 2022 from the tunnel boring staging pit at the intersection of Thornton Street and Great Northern Way, which doubles as the pit for Great Northern Way-Emily Carr Station. Elsie was initially the lead tunnel boring machine, before being overtaken by Phyllis in the middle of 2023.

Tunnel boring was originally scheduled to reach completion in late 2023 to maintain the project’s schedule of reaching completion and opening in early 2026. It remains to be seen how the delays will impact the precise completion and opening timeline.

The remaining work on the overall construction project could not fully advance until tunnel boring reached completion. Now that tunnel boring is done, the equipment for tunnel boring will be removed, and construction can pick up in pace for all subway station structures, and the tracks and equipment within the lengths of tunnel.

Tunnel boring was supposed to begin in Summer 2022, but the launch of the machines was delayed due to a weeks-long strike of Lower Mainland concrete plant workers, which pushed the subway’s opening from late 2025 to early 2026.

Then, there were more extensive delays in the middle of 2023. Compared to other station pit pass-throughs, both machines also experienced a much longer maintenance dormancy and boring pace at Broadway-City Hall Station in the late spring and early summer of 2023. According to the provincial government, extra precautions were taken before boring beneath the Canada Line tunnel underneath Cambie Street.

arbutus station broadway subway tunnel boring april 18 2024

Tunnel boring and construction on Arbutus Station at Cypress Street, as of April 18, 2024. (Kenneth Chan/Daily Hive)

Upon opening, Broadway-City Hall Station will become one of the region’s busiest SkyTrain stations, as it will be transformed into a seamless interchange hub between the Millennium Line and Canada Line.

Each construction pit for Broadway-City Hall Station and Arbutus Station is two city blocks long, as both stations are also immediately adjacent to a major crossover track switch.

The Arbutus Station pit is two blocks long between Cypress Street and Arbutus Street, with the eastern block between Cypress Street and Maple Street used for a major track switch enabling trains to turn around from the terminus station, and the western block between Maple Street and Arbutus Street used for the subway station structure itself.

The $2.8 billion, 5.7-km-long extension of the Millennium Line will add six subway stations to the SkyTrain network. A length of five km is underground, but there is also a 700-metre-long elevated segment between the existing VCC-Clark Station and the tunnel portal just before Great Northern Way-Emily Carr Station.

In Summer 2024, the new infill Capstan Station on SkyTrain Canada Line will finally open roughly midway between Bridgeport and Aberdeen stations. Capstan Station was originally supposed to reach completion in Summer 2023.

Later in 2024, major construction work will also begin on the 16-km-long, eight-station Surrey-Langley Extension of SkyTrain Expo Line, which is scheduled to reach completion by late 2028 at a cost of $4 billion. The Broadway Extension and Surrey-Langley Extension will mark the first time the major construction work timelines of two SkyTrain extension projects overlap. With the Broadway Extension and Surrey-Langley Extension, the SkyTrain network will reach a milestone length of over 100 km.

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