Final preparations for the tunnel boring machine (TBM) arrival at Flower and 4th streets in downtown Los Angeles are underway on the Regional Connector project.
This weekend, the Financial District intersection will be closed from 7 p.m. Friday, July 7,through Monday, July 10, ending at 5 a.m. This first closure (in a series of ten weekends) will allow crews to begin the process of installing the strand jack gantry crane that will be used to remove the cutterhead and shield portion of Angeli (the tunneling machine’s name) when tunneling for the first of the twin tunnels is completed.
In the meantime, here’s a fresh batch of photos of the tunnel between the future Grand Ave Arts/Bunker Hill Station near 2nd and Hope and 4th and Flower. To date, Angeli has dug 5,120 feet from the Little Tokyo station with roughly 700 feet to go.
One big challenge with tunneling efficiently is quickly troubleshooting mechanical issues and efficiently moving the whole tunnel assembly line forward in the tunnel with all its support wiring, pipping and conveyor systems . In these photos you can see crews maintaining water lines, building temporary tracks and installing new tunnel ring segments.
After the TBM breaks through at 4th and Flower, the machine will be retrieved from below ground and the massive pieces will be transported by truck back to Little Tokyo. The TBM’s trailing gear will be sent backwards through the finished tunnel.
The cutterhead and shield will be lowered back into the ground and reunited with the trailing gear at the Mangrove Yard in Little Tokyo and the TBM will be relaunched to being digging the second tunnel by the end of the summer. The second tunnel is scheduled to completed by the end of 2017.
The Regional Connector project is building twin 1.9-mile rail tunnels under DTLA that will tie together the Blue, Expo and Gold Lines to create faster and more frequent light rail rides to and through DTLA. When the project is complete, Metro will begin running two light rail lines — one between Azusa and Long Beach and the other between East Los Angeles and Santa Monica. The two lines will share five stations in DTLA, making it very easy to transfer between them.
The project is funded by Measure R and state and federal grants.