Mar
30

Once more unto the Second Ave. rabbit hole

By · Published in 2011

ADI, the Second Ave. Subway TBM, has begun to dig out the route's eastern tunnel. (Photo by Benjamin Kabak)

The MTA hosted no ribbon-cutting ceremony yesterday nor did local politicians make the trek underground to mark the occasion, but this past week was a big one for the Second Ave. Subway. Adi, the tunnel boring machine that had recently finished digging out the west tunnel, got to work on the east tunnel, the MTA has announced.

Since June 2010, Adi had been hard at work digging out 7162 linear feet for the western tunnel. It mined from 92nd St. underneath 2nd Ave. to 65th Street. Crews will have to blast out the final three blocks to connect the eventually downtown track with the preexisting tunnel underneath 63rd St.

The eastern tunnel, though, will connect through to the unused half of the F train’s 63rd St./Lexington Ave. stop. The second tunnel will be 7800 feet long, and the authority described the route: “On its journey, the second tunnel will make a tight, westerly curve into the existing 63rd Street Station. Once completed, the tunnel will receive the concrete lining which provides the permanent tunnel structure.”

The MTA again reiterated that the Second Ave. Subway remains on track for a December 2016 revenue service date, but as we know, the authority’s construction timelines tend to be somewhat flexible near the end. No matter the eventual wrap date for Phase 1, it seems as though economics, politics and a tunnel boring machine will push the Second Ave. Subway off the pages of the city’s history books and onto the subway map before too many years are up. Too much work has happened for the line to fail now.



24 Responses to “Once more unto the Second Ave. rabbit hole”

  1. Alon Levy says:

    Off-topic, a colleague from Barcelona tells me that in Madrid they save money by keeping the TBMs at the end of the tunnel, for easy future extensions. Could this be done in New York to make future phases of SAS cheaper?

    • Depends on the lease terms for the TBM. What isn’t going to happen, but should, is planning and funding of Phase 2 before Phase 1 is completed. That way, they could use the same TBMs. Although they would likely to have to turn the thing around to drill north instead of south.

      • Scott E says:

        They don’t need the TBM for Phase 2, except to make the curve from 120th & 2nd to 125th & Lex, under the existing 4/5/6 station (I’m not sure where the launch box goes). It’s all either existing tunnels, or cut-and-cover stations.

      • Justin says:

        Whatever happened to the 3 billion reclaimed by the feds from the canceled NJ Transit Tunnel project? I know New York’s politicians have bid on that for the MTA. Florida’s governor also canceled a high speed train that the federal government was going to pay 90% off. NY and California have bid on this money as well. Since is going to take 5 more years before Phase 1 is complete, its possible that NY might actually get money from these canceled projects and be able to fund phases 2 and 3. We can pray for it!!!

        • Alon Levy says:

          The Florida HSR money comes out of a separate pot, usable only by intercity trains that call themselves high-speed (of which none is actually high-speed, except California and Missouri, but that’s a separate issue).

          The Jersey ARC money I’m not sure about. Didn’t it come out of an earmark, which means it’s not automatically distributed to other grant applications?

    • Redbird says:

      This is not out of the question, but there are several issues to consider.

      (1) Will the next tunnel project use the same type of TBM? (Right now ESA, 7-Line Extension, and SAS all use different types of TBMs–slurry shield, double shield, main beam respectively). If you are fairly certain of the geology of future portions, this might be a good idea.

      (2) After digging the 14,000 or so feet of tunnel, the TBM will need MAJOR rehab. ADI has been rebuilt several times now, after each job. Before it started its current run, it underwent somewhere around $10M of rehab. This would likely need to be done before the next run as well. There becomes an issue of who takes liability for this–does the MTA warranty that the next contractor gets a functioning machine? I would guess a contractor who builds tunnels would be better able to rehab a machine (to meet their needs) than the TA would. I can see very costly construction claims coming out of this.

      (3) Restriction of “means and methods.” Typically, the contractor is left to choose the exact equipment they want to use to fit their plan of attack for a job. If the TA starts dictating what machine to use, you lose a lot of contractor creativity on how they want to build. For instance, the MTA allowed the contactors choice of a main beam TBM or a segmental liner machine (double shield) and the contractor’s got to choose what they thought was a better machine.

      (4) Also, the cost of the TBM itself if minor compared with labor in the NY market. Sandhogs cost $100/hour (including benifits) for 8 hours, after which they make double time. This coupled with arcane labor agreements that require certain numbers of men on each operation (several times what is used abroad–where labor is much cheaper) are what make the cost of digging a tunnel so high in NYC. Until the labor rules are relaxed, costs will still be very high.

      • Alon Levy says:

        The reason my colleague cited for Madrid’s keeping the TBMs is that there’s no need to extract them and then put them back in every phase. This means there’s no need for a new launch box for every extension.

        Also, although all European countries are cheaper than the US, even notoriously high-cost Britain, Spain has unusually low construction costs. Implementing some of the practices used in Madrid could therefore cut the costs in New York independently of contractor and labor rule reforms, which should be undertaken regardless.

  2. Clarke says:

    Are they going to leave southern stub tracks to allow for a seamless integration of Phase III? (I’ll venture a guess…probably not.)

    • Jerrold says:

      THAT is a very good question.
      Advance planning always pays off.
      Imagine what the ESA project would be costing now if the lower level had not been included when they built the 63rd St. tunnel.

      • Clarke says:

        Imagine if ESA would have even happened if the lower level of the 63rd St tunnel hadn’t been included.

        • al says:

          No lower level on the 63rd st tunnel would had put the MTA into a bind where green lighting a subway to LIRR connection (with signal and rolling stock upgrades) would had been the only option to increase service levels between Long Island and Manhattan.

          One could imagine the B/Q/F and maybe the BMT Jamiaca or Myrtle Ave over the Christie Street connection into Queens over the LIRR, and maybe an elevated line over AMTRAK, BQE, GCP, and Van Wyck to LGA, Mets/USTA/FMCP, and JFK.

  3. Frank B. says:

    Perhaps it would be cheaper to simply purchase a tunnel boring machine and use it to drill tunnels all throughout the city, on a long-term basis, rather than simply leasing one over-and-over again. Drill to Staten Island! Drill throughout Queens!

    Even if it costs $10 million to rebuild each time, I imagine it would still be cheaper. Or would we have to use expensive labor, so it wouldn’t even be worth the trouble?

    • R. Graham says:

      As mentioned above. Each TBM is different for a variety of reasons. The TBM being used in LIC is specifically made to tunnel through soft most ground while leaving a pre-cast liner that’s strong enough to stand on it’s own.

      The TBM that was used to dig the 7 line extension is smaller than both the one being used in LIC for ESA and Adi being used to drill the SAS. It’s made to drill through bedrock and just large enough to drill a IRT size tunnel. The second newly built IRT tunnel in this city in quite a long time when you don’t include the 1 line rebuild after 9/11 but do include the new South Ferry Station.

      The TBM used for the SAS is large and made for drilling through NY bedrock, but is not designed to handle soft ground. When the TBM reached soft rock in the 70s area of Second Avenue the ground had to be frozen ahead of the TBM. Yes frozen to ensure the ground wouldn’t collapse and then the sandhogs had to immediately add a special re-enforced liner to prevent against current and future destablization.

  4. Eric F. says:

    How the heck did they get that thing into Manhattan?

    • On a truck in pieces. It was reassembled underground.

      • Eric F. says:

        Just getting it there/assembling it must have been an enormous project. That’s one aspect of NYC that never ceases to amaze me. Similarly, all the materials being trucked into the Groudn Zero site each day must constitute an enrmous weight and volume, but it seems to occur with very little disruption and visibility.

        • Hank says:

          I live right by the SAS launch box and it’s been impressive watching the assembly and operation of the TBM.

          That being said, stub tunnels for Phase 3 should DEF be included in this run.

          Couldn’t add that much more cost.

  5. Morgan says:

    Do you know anything about restitution for this on going project? I live on the battle ground at the corner of 96th and 2nd and am slowly losing any hope of sanity. The noise is constant and deafening. Any hope for relief? Or compensation for the annoying daily disruptions?

Trackbacks/Pingbacks

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  2. […] news earlier this week that the tunnel boring machine digging out the Second Ave. Subway will soon start to burrow out the eastern tunnel, the MTA has again been forced to scale back the project. Due to the $10 billion gap in the capital […]

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