First tunneling machine reaches future Wilshire/La Cienega subway station

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In this and the following two pics, the tunnel boring machine arriving last week at Wilshire/La Cienega Station. Photos by Ken Karagozian for LA Metro.

Metro today announced that its first Tunnel Boring Machine (TBM), named Elsie, on Thursday broke through to the Wilshire/La Cienega subway station in Beverly Hills. It is the first of two TBMs that will reach this last station on Section 1 of the Metro D Line (Purple) Extension project.

Tunneling for the first four-mile section of the subway project is now two-thirds complete. More than 90 percent of the tunnels have been mined safely and Metro anticipates completing tunnel mining this summer. Excavation for all three subway station boxes beneath Wilshire Boulevard has been completed.

Elsie, the 1,000-ton, 400-feet long Tunnel Boring Machine (TBM), started west at the Wilshire/Fairfax station on May 29, 2020, and broke through to the Wilshire/La Cienega station site about one mile away on February 25. Metro’s first TBM “Elsie” arrived at Wilshire/Fairfax on April 4, 2020.

Reaching this milestone is a significant win for Metro. Section 1 of project tunneling has presented challenges that have been successfully overcome by the project. En route to Wilshire/La Cienega, the agency’s modern, high-tech TBMs have mined through a unique combination of soils and geologic conditions, including tar sands and methane gas.

Metro’s TBMs were first lowered into the ground at Metro’s Wilshire/La Brea station site in the Miracle Mile area of Wilshire in October 2018. While advancing, the TBM tunneled about 60 feet per day. They worked five days a week, 20 hours a day.

Metro’s TBMs are pressurized, closed-face machines that minimize ground settlement during excavation. The tunnel is lined with precast concrete segments that are bolted together to form a ring. Segments are also gasketed to make the joints between segments water- and gas-tight.

When tunneling is finished for this project section, both of Metro’s TBMs will have mined nearly half a million cubic yards of earth — the equivalent of filling 2.3 million bathtubs with dirt.

The TBMs were manufactured in Germany by Herrenknecht AG. Metro has contracted with Skanska Traylor Shea (STS), a joint venture to design and build the first section of the project.

The $9.3-billion Metro Purple Line Extension is a nine-mile underground subway project that will extend the Metro Purple Line from its terminus in Koreatown to Westwood/VA Hospital in West Los Angeles. Section 1 is expected to be completed in 2023, Section 2 in 2025 and Section 3 in 2027.

For more information on the Purple Line Extension Project, go to www.metro.net/purplelineext.

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8 replies ›

  1. I really wish we get on the ball with planning an extension to Ocean BLVD.

  2. Talk about a WIN! I’ve been advocating for this subway extension under Wilshire since the service to Wilshire and Western first started! I’ve watched this closely, through all of the delays and debacles and the methane gas issue, when THAT started in the 1980s, canceling the original route up Fairfax! So, now I’m a lot older and just hoping I live long enough to enjoy total vindication and ride that first train to Westwood!

  3. Nice work. Mining through the Tar Pits area can’t be easy. Is there any TBM video available from that section?

  4. Do these tunneling machines wear out after each phase or does the MTA and its contractors just discard them in order to rid themselves of these oversized piece of equipment that are in their way?

  5. So, Metro owns these machines? Or does the contractor? This article keeps saying “Metro’s TBMs”. My understanding is that the contractor owns them.

    • Hi Just a Person;

      The contractor owns them. But as it’s our project and we’re paying for them, we oft refer to them as Metro’s.

      Steve Hymon
      Editor, The Source

      • Under that logic you should refer to the USPS’s delivery equipment as yours. And you should refer to the saw of the carpenter who is working on your house as yours. You are paying for the service and in the second case, the project. But, you don’t own the items. Unless the contract is very special, Metro has no (potential) claim on the TBM’s.