Fresh pics: first Regional Connector rail tunnel under Bunker Hill

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.

18 replies

  1. Did they build a station box at 5th/Flower in case they want to add the stop to the project at a later time?

  2. One thing the Regional Connector is apparently missing is a wye at the 1st Street junction between the Gold Line East Side line and the Blue Line.

    This would allow the east side patrons to have one-seat access to Union Station as they do now. This will be even more desirable when the east side line is extended further east.

    In addition, LA Metro should route a large portion of the Santa Monica Line trains to serve Union Station.

    In reality, when the various existing lines are extended to cities further east, this could increase the congestion on the connector,

    Hopefully the Wast Santa Ana Branch will have its own access to Union Station that could be connected to the various east side lines, with underground tunnels with moving sidewalks connecting the various rail lines.

  3. It would be nice to see a detailed street map showing the proposed track locations of the underground wyes for the Regional Connector!

    • It’s basically under the intersection of Alameda and 1st. There probably is a schematic in the project’s FEIS/R.

      Steve Hymon
      Editor, The Source

  4. the word Farther is appropriate for distance such as extending a line heading to the east.

  5. Will there be a place to turn around trains mid-route once the regional connector opens? Based on ridership numbers, the current Blue and Expo lines seem to warrant higher frequency trains than the current Gold line. Will there be a mechanism to allow differing frequencies within a line once the regional connectors open or is downtown Santa Monica going to get the same train frequency as East LA Civic Center?

    • There’s no formal turnaround per se, but there (as always) will be places where trains can switch tracks and turn around. That said, there aren’t plans to do that.

      I do think that the Connector will help bump up ridership on the Gold Line. The Eastside part of the line now requires riders to first go to Union Station and transfer to the subway to travel to the heart of DTLA. That’s a huge time munch that doesn’t provide much incentive to ride. The Gold Line from Azusa also requires the transfer to continue to heart of DTLA — not quite as out-of-the way as on the Eastside part of the line, but my experience is the transfer still gobbles up five to 10 minutes. The Connector will allow those trains from Azusa to go straight into DTLA with no transfer. I think that will make the Gold Line more appealing.

      All that said, I don’t think it’s the worst thing in the world if demand is not uniform across the entire system — I think there are few transit systems in which that’s the case. The Connector will also get rid of the turnaround for Blue and Expo trains at 7th/Metro and help alleviate some of the train congestion between 7th/Metro and the junction at Washington/Flower. According to the project’s FEIR, trains could run as much as every five minutes on each of the two lines or every 2.5 minutes on the DTLA section of track the two lines will share.

      Steve Hymon
      Editor, The Source

      • Thanks, very helpful information! So assuming equal distribution between the lines going through the Connector, the shortest headway for the current Expo and Blue lines is 5 minutes (from the current 6 minute headways). I could definitely see 5 minute headways not being sufficient on present-day Expo once the Crenshaw line opens, but it sounds like given the capacity limitations of the connector (not to mention the current wye issues right as you get into downtown) the headways can’t get shorter than 5 minutes. Since Crenshaw should open before the Connector, hopefully this will give Metro some time to make any quick fixes that are necessary but that would be a very short turnaround time…hopefully Metro can get out ahead of this potential (likely) issue!

        • One other thing to consider is that eventually Crenshaw/LAX Line will get extended north and the Expo Line won’t be its northern terminus. I think once that happens, a lot of Crenshaw/LAX riders stay on the train and transfer to the Purple Line or ride north to other destinations in WeHo or Hollywood.

          Steve Hymon
          Editor, The Source

          • Here’s hoping that PPP (or some other funding source) comes in because the wait from 2019 until 2047 is a long one!

  6. how would ridership change between 7th/Flower and Washington Blvd? Do you mean congestion between 7th/Flower and Union Station?

    • The Connector would allow more trains to run on that segment. The train congestion I referenced is presently between Washington/Flower and 7th/Metro, where all Blue and Expo trains must turn around. Traffic signals are also an issue.

      Steve Hymon
      Editor, The Source

  7. Steve, rethink this sentence: “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 station with roughly 700 feet to go.” If the macine is to dig nearly 6,000 feet from the 2nd/Hope pit, that would put it down near the convention center, wouldn’t it? This misidentification is causing a conflagration on the L A Curbed website.

    • Hey John —

      Thanks for the heads up. That should be 5,120 feet from Little Tokyo Station. I fixed it.

      Steve Hymon
      Editor, The Source

  8. No plans to build switches or track to allow service between Long Beach and Santa Monica? I know that it could be done via transferring to the Green Line and Crenshaw line or just driving the 405 or PCH/Sepulveda/Lincoln, or just switching at Pico, but I imagine that interlining could potentially mitigate capacity issues at stations at Pico.