L.A. Metro Celebrates Unveiling and Naming of Tunnel Boring Machines for Purple Line Extension Project

April 26, 2018
Metro joined elected officials and community members in L.A.’s Mid-Wilshire District for a ceremonial naming and unveiling of its tunnel boring machines that will dig twin four-mile subway tunnels.

The Los Angeles County Metropolitan Transportation Authority joined elected officials and community members in L.A.’s Mid-Wilshire District for a ceremonial naming and unveiling of its tunnel boring machines that will dig twin four-mile subway tunnels under Wilshire Boulevard for the Metro Purple Line Extension Project. Subway tunneling is expected to begin later this summer.

Metro Board Chair and Los Angeles Mayor Eric Garcetti awarded TAP Cards and other prizes to students who won contests to name the TBMs and create illustrations for the TBM tail shields. Over 1,700 votes were cast for the contests from across L.A. County. The names “Elsie” and “Soyeon” (pronounced “So-Yun”) were selected from a winning entry submitted by Fairfax High School student Marianne Gutierrez. Soyeon is Korean for “bright” and “beautiful” and was named after female astronaut and mechanical engineer Yi Soyeon.  Elsie was named after Elsie Eavers, the first female to be elected as a member of the American Society of Civil Engineers.

Lauren Park, a third-grade student from Palm Crest Elementary in La Canada who also goes to Prism Art School in Koreatown after school, won the art contest. Her winning illustration showed her ideal community, which included Purple Line Extension service. Metro will issue commemorative TAP cards featuring Lauren’s winning artwork at 7th Street/Metro Center, Wilshire/Vermont and Wilshire/Western Purple Line Stations beginning April 26

“I’m proud to introduce our two newest Angelenos — Elsie and Soyeon — who embody the ambitious, resilient spirit of Los Angeles,” said Metro Board Chair and Los Angeles Mayor Eric Garcetti. “Their work will bring us one step closer to realizing an integral part of our transportation future — a 25-minute subway ride from Downtown to the Westside.”

Metro has received the cutterhead and shield for its tunnel boring machines, which are now staged at Metro’s Wilshire/Fairfax station construction yard. TBMs will ultimately be assembled at the Wilshire/La Brea station site and will first travel east to Wilshire/Western in Koreatown. From there, parts of the TBMs will be retrieved from underground, with the rest moved back to the La Brea Station through the new tunnel.  TBMs will then be reassembled and relaunched west to Beverly Hills as part of the first construction segment.  Metro contractor Skanska, Traylor Shea, a Joint Venture, is builidng this portion of the project.

“The Purple Line Extension will be a game changer for the entire L.A. region,” said Metro CEO Phillip A. Washington. “We are working aggressively to provide fast, frequent, reliable subway service between our county’s two largest employement centers. This high-priority transit line is part of a much larger countywide transportation building boom that will create an infrastructure inheritance for future generations of Angelenos.”

The TBMs are manufactured in Germany by Herrenknecht AG. They weigh approximately 1,000 tons, are 450 feet long and are 21.5 feet in diameter. They will advance about 60 feet per day once digging begins. Twin tunnels will be separated from each other by approximately 16 feet of soil. Tunnels will be approximately 50 to 70 feet deep, though some areas will be deeper. TBMs will tunnel five days per week, 20 hours per day and take approximately two years to mine both subway tunnels.

Naming of the TBM is a mining tradition that dates back to the 14th century. Saint Barbara, the patron saint for military engineers and miners, has been revered by underground workers as a symbol of protection and good luck for centuries. This homage evolved into the tradition of giving tunneling machines a female name before digging begins.