Tunnel boring work set to begin for L.A. Metro rail extension

Two state-of-the-art tunnel boring machines (TBMs) will soon begin work on Section 2 of the Los Angeles County Metropolitan Transportation Authority’s (Metro) Purple Line Project, aided by the engineering and design services provided by STV, a transportation and infrastructure firm.

Working as part of the design-build team led by Tutor Perini and O&G Industries, STV is serving as the engineer-of-record and principal design firm for the 2.6-mile-long Purple Line Section 2 extension that will link Section 1 running through the Miracle Mile District with Section 3 connecting Century City to Westwood. Overall, the $6.3 billion Purple Line extension will run 9.1 miles from Koreatown to Westwood.

STV’s services include the design of stations at Beverly Hills and Century City along with the running tunnels. The firm also engineered and designed the so-called “launch box” in Century City where the two 400-foot-long TBMs will be lowered into excavations extending more than 70 feet below Constellation Boulevard to begin their 14- month journeys.

The construction of the Beverly Hills and Century City stations will use a cut-and-cover method to build entrances, platforms, and concourses along with additional space for power, ventilation systems, and communications. STV will also be providing engineering and design services for the trackwork, traction power, train control, and communications systems.

Section 1 of the Purple Line is nearly a third complete and is scheduled to open in 2023. Section 2 is expected to be completed by 2025 with Section 3 scheduled to open shortly after in 2026. Once completed, the subway ride from downtown Los Angeles to Westwood is expected to take about 25 minutes.