A couple of weeks ago, Metro celebrated its “Half-Way to La Cienega” event for Section 1 of the Purple Line subway extension. And since then it has reached another milestone worth celebrating – the arrival of both Purple Line Tunnel Boring Machines (nicknamed Elsie and Soyeon) at Western Ave.
The two machines, which are digging two parallel tunnels (eastbound and westbound) simultaneously, and insering the concrete tunnel lining as they go, were launched from La Brea Ave. in October, 2018.
Soyeon, digging the tunnel on the north side of the route, broke through to the Western Ave. station area on June 11…and Elsie, digging the tunnel on the south side, broke through on June 28, according to Metro’s The Source blog.
On June 11, The Source posted about the first event in a story containing video of the breakthrough moment:
“The 1,000-ton, 400-feet long TBM named “Soyeon” burrowed through the last remaining cluster of soil 50 to 70 feet below busy Wilshire Boulevard Tuesday afternoon, June 11. The TBM is one of two TBMs to mine approximately two miles of parallel subway tunnels between the future Wilshire/La Brea Station and the existing Wilshire/Western Station.”
The story went on to say:
“Soyeon was originally lowered into the ground at Metro’s Wilshire/La Brea station site in the Miracle Mile area of Wilshire last October. While advancing, the TBM burrowed about 60 feet per day. It worked five days per week, 20 hours a day.
The digging has taken eight months to reach the bulkhead — the retaining wall at the face of the Wilshire/Western subway terminus. Metro anticipated future westward subway expansion and built the bulkhead wall as part of station construction. The station originally opened in 1996.”
Then, in a second story posted in The Source on June 28, Metro announced:
“It’s official. Elsie, Metro’s second tunnel boring machine for the first section of the Purple Line Extension, has made it to Wilshire/Western Station in Koreatown. The Goliath-sized TBM made it to the station at 3:57 p.m. on Thursday (June 27) — the tunnel at left in the…photo [below].”
The two TBMs will now be transported back to La Brea, where they will be re-inserted into the station site, facing the other way, and will begin their journey toward Fairfax Ave., and then La Cienega Blvd. According to Metro, the machines are expected to reach the end of Section 1, at La Cienega, by mid-2020. Meanwhile, two other TBMs, Ruth and Harriet, will also begin the tunneling for Section 2 of the Purple Line Extension, from La Cienega to Century City, in 2020.