Her Work Done on Crenshaw’s Underground Railroad, Harriet the Tunnel Boring Machine Retires

Earlier today, Streetsblog L.A. got the chance to go deep below Crenshaw Boulevard to attend Metro’s retirement ceremony for the tunnel boring machine (TBM) that has completed its work on Metro’s Crenshaw/LAX line. The machine is named “Harriet” after the heroic abolitionist Harriet Tubman.

The new Crenshaw/LAX line started construction in early 2014. The project is currently over 60 percent complete. The 8.5-mile line will extend through South L.A. and Inglewood from the Expo Line’s Crenshaw/Exposition Station to the Green Line’s Aviation Station. The new light rail includes portions above, below, and at grade.

For a good overview of the Crenshaw/LAX project, watch a fly-through video embedded in this earlier SBLA article.

Despite some construction delays, including some due to heavy rains this winter, the Crenshaw/LAX line is expected to open to the public in Fall 2019.

Harriet dug two one-mile-long tunnels at the north end of the Crenshaw/LAX line. The tunnels extend below Crenshaw Boulevard from Exposition Boulevard to Vernon Avenue. This stretch of the line will have three underground stations: Crenshaw/Exposition, Martin Luther King Jr. Boulevard, and Leimert Park. South of Vernon Avenue/Leimert Park, the line runs on the surface.

There is no elevator at Metro’s construction site at Leimert Park. Event attendees were lowered down into the construction site via a metal cage lowered and raised by a crane.

The Leimert Park Station underground box is cavernous–quite a bit bigger than completed Metro subway stations. At the northern end of the site sat Harriet’s 21.5-foot diameter cutter head, attached to its 30-foot-long cylindrical shield. The fully-assembled tunnel boring machine is 400 feet long, weighs 950 tons, and is operated by a crew of 75 workers in three shifts.

Harriet began tunneling at Expo/Crenshaw on April 26, 2016 and completed its first tunnel on October 20. It was then shipped back to Expo/Crenshaw, and dug its second tunnel from November 29 through April 6. The TBM tunneled at a rate of roughly 60 feet per day.

The retirement ceremony featured brief remarks by Metro leadership including board Chair John Fasana, County Supervisor Mark Ridley-Thomas, boardmember Jacquelyn Dupont-Walker, CEO Phil Washington, and contractor representative Peter Shea. Washington stressed the importance of this major transportation infrastructure project, improving lives now through creating middle class jobs, and later through improved mobility helping South L.A. access education and jobs.

Below are more photos from today’s event.

Congratulations on your underground railroad, Harriet!

For more information on the Metro Crenshaw/LAX line, see Metro’s project page.