And so it begins: Tunnel boring now underway for Broadway Subway

Dec 28, 2023

The tunnel boring machine named "Elsie" for the SkyTrain Millennium Line extension has now begun its journey from the site of Great Northern Way-Emily Carr Station in the False Creek Flats towards the site of Arbutus Station in Kitsilano.

It is one of two five-km-long tunnels that will be bored from the staging area next to Emily Carr University of Art & Design, which will double as the station construction footprint after tunnel boring work is fully finished.

While "Elsie" will create the Millennium Line's eastbound direction tunnel, a second boring machine named "Phyllis" will build the second tunnel for the westbound direction. The assembly process for "Phyllis" began in mid-September, and she will be launched separately this winter.

To mark the occasion, the provincial government did not stage a typical tunnel boring groundbreaking ceremony with dignitaries and media.

The machines are named after Elizabeth (Elsie) MacGill and Phyllis Munday — decorated British Columbians who were leaders in engineering and mountaineering.

Each machine has a diameter of six metres and a length of 150 metres. From the tunnel boring pit, they will bore twin tunnels at a pace of about 18 metres a day, with each machine manned by eight to 12 staff around the clock.

If all goes as planned, it will take about one year for each machine to reach the intersection of Cypress Street and West Broadway — the site of a track switch just east of the future Arbutus Station.

The machines will pass through the excavated pits of five subway stations directly below Broadway — at Main Street (Mount Pleasant Station), Cambie Street (Broadway-City Hall Station), Laurel Street (VGH-Oak Station), Granville Street (South Granville Station), and Arbutus Street (Arbutus Station).

Mount Pleasant Station. #BroadwaySubway #SkyTrain pic.twitter.com/tSUKkkKsNs

— Kenneth Chan (@iamkennethchan) June 19, 2022

Early October 2022: assembly process for Broadway Subway tunnel boring machines, Elsie and Phyllis. (Government of BC)

Early October 2022: assembly process for Broadway Subway tunnel boring machines, Elsie and Phyllis. (Government of BC)

About 200,000 cubic metres of excavated soil and rock will be transported to the pit by a conveyor system. The concrete rings that will line the tunnel were manufactured in Nanaimo and have been transported to the pit.

When it opens in late 2025, the seamless Millennium Line Broadway Extension will reduce public transit travel times between Commercial-Broadway Station and the new terminus of Arbutus Station to just 12 minutes. Between Lafarge Lake-Douglas Station in Coquitlam and Arbutus Station on a one-train ride with no need to transfer, it will take about 47 minutes. Upon opening, the extension is expected to see 150,000 boardings per day.

The entire project carries a cost of $2.83 billion with $1.73 billion going towards the private contractor consortium led by Spanish engineering giant Acciona and Italian tunneller Ghella.

Ghella selected German tunnel boring machine equipment manufacturer Herrenknecht as its supplier for this project.

Early October 2022: assembly process for Broadway Subway tunnel boring machines, Elsie and Phyllis. (Government of BC)

Tunnel boring machine "Elsie" drilling for the Broadway Subway. (Government of BC)

The tunnel boring process for the Broadway Extension is different from the Canada Line, which used a single TBM for both of its tunnels by returning the machine back to its starting point for its second run, while the Evergreen Extension used a single large TBM with a width of 10 metres (33 feet) to build a single tunnel that contained the tracks for both directions.

However, the subway is not the region's first tunnel boring project since the completion of the Evergreen Extension. Metro Vancouver Regional District's various water supply projects have used smaller TBMs to complete major piping lengths.

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