Regional Connector crews last weekend extracted the tunnel boring machine (TBM) cutterhead and one shield segment from underground — at 4th and Flower streets in downtown Los Angeles. The TBM recently completed digging the first of two tunnels for the project and must now be disassembled and transported back to Little Tokyo, where it will begin the second tunnel later this year.
In order to lift such heavy machinery, a specialized crane was assembled over Flower Street and used to gradually lift each segment. The cutterhead alone weighs 144,000 pounds. This same type of crane will be used to lower and piece the machine back together in Little Tokyo.
To complete their work, crews transported the cutterhead and shield segment to Little Tokyo using a heavy-duty dolly. Crews waited until the middle of the night to close down 7th Street to ‘walk’ the machine across DTLA. The remainder of the TBM shield will be retrieved this weekend and the crane will be demobilized the following weekend.
The Regional Connector will connect the Blue, Expo and Gold Lines via twin 1.9-mile light rail tunnels in DTLA. When complete, Metro will operate two light rail lines. One will run from East Los Angeles to Santa Monica and the other between Azusa and Long Beach. The two lines will share five stations in DTLA and the project will make light rail trips to and through DTLA faster with fewer transfers.
The project is currently forecast to be completed in late 2021. It is funded by Measure R, a federal New Starts grant and other state and local sources.