LA County Metro Unveils Two New TBMs for Purple Line Extension
The Los Angeles County Metropolitan Transportation Authority (Metro) on Monday unveiled two new tunnel boring machines (TBMs) for the authority’s $9.3 billion Purple Line Extension project, which will connect subway transit service from downtown Los Angeles to the city’s westside by 2027.
The new TBMs will be used to dig two subway tunnels between downtown, and the Los Angeles neighborhood and business district Century City and the city of Beverly Hills for Section 2 of the 9-mile subway extension project. Section 2, of three, broke ground in February and will include 2.59 miles of track with two new Metro stations, Wilshire/Rodeo and Century City/Constellation.
When complete in 2027, the Purple Line will connect Metro’s Wilshire/Western Station, in the city’s Mid-Wilshire/Koreatown’s district, to the westside in 25 minutes, versus a current car or bus commute of one hour or more. The subway extension is expected to increase service by 17,000 new riders; an estimated 60,000 riders currently use the subway daily. The project is funded by ballot-elected sales tax devoted to transportation investments – Measure R approved in 2008 and Measure M in 2016 – and federal grants.
The Purple Line’s expansion reached a major milestone last October, when two TBMs began carving out twin tunnels for the project’s Section 1. Section 2 tunneling will begin early next year, and the four TBMs will work simultaneously. Manufactured in Germany by Herrenknecht AG, the TBMs each weigh 1,000 tons and are 400 feet long and 21.75 feet in diameter. Metro expects the Section 2 TBMs to advance 60 feet per day and operate tunnel five days per week, 20 hours per day for a projected 2 years to completion. Tunnel depths will range from 50 feet to 120 feet.
Metro says it received the cutterhead and shield for its TBMs, now staged at Metro’s Century City Station construction yard, where they will be built before digging eastward to Wilshire/La Cienega in Beverly Hills. Tutor Perini O&G, Metro’s Section 2 contractor, is building this portion of the project.
Beverly Hills Mayor John Mirisch said at the unveiling ceremony that his city looks forward to Metro’s future exploration of public transportation beyond heavy rails, “that can lead to other forms of public transportation into an integrated system that ultimately will have the goal of getting people from point A to point B whenever we want to go as quickly as with our own cars.”
“I think that will ultimately represent the true democratization of public transportation and all of us should be on board with that,” Mirish said
Metro also announced student winners of contests naming the TBMs and illustrating their tail shields. Sixth-grader Ruby Santamaria’s winning entries for “Harriet” and “Ruth” were named after abolitionist and Underground Railroad “conductor” Harriet Tubman and U.S. Supreme Court Justice Ruth Bader Ginsberg. Third-grader Hans Smallwood’s illustration rendering the Purple Line Extension subway under Rodeo Drive won the art contest.
Meanwhile, Metro says that, beginning June 22, Expo Line service at the 7th St/Metro Center and Pico stations will close for construction work as part of the Blue Line Improvements Project. Metro expects the stations to reopen in late August.
Created in 1993, Metro is a multimodal transportation agency that transports 1.3 million passengers daily on 2,200 clean air buses and six rail lines.
