Second Ave. Sagas

CBTC tests on L line a bit jerky

Written by

Benjamin Kabak

in

The MTA and Siemens have had a rocky relationship. The technology company won the contract to install train arrival boards along the L line and to equip the line with computer-based train control. As those projects are both behind schedule, the two sides have engaged in some finger-pointing in the past.

Now, as New York City Transit tests CBTC-equipped trains on the L line, the two companies are again dealing with some issues concerning the technology. According to an engineering report, the CBTC works as it should with one major exception: The trains suffer through an “uncomfortable jerk” as they pull into stations. Heather Haddon of amNew York has more:

In February, NYC Transit started running some overnight L trains on “automatic train operation,” where a driver simply taps a button as a computer handles most of the driving.

So far, the software may need tweaking to stop the jerking motion, along with braking errors at fast speeds, according to a report prepared by McKissack + Delcan, engineers hired to oversee the MTA’s major projects.

The snafu has not endangered passengers, NYC Transit spokesman Paul Fleuranges said. Siemens Transportation Systems, the contractor, will be held responsible in refining the software, he said.

Union leaders, worried about the potential loss of jobs that completely mechanized trains represent, used these problems to rail against CBTC. Curtis Tate, current head of TWU Local 100, called for an investigation into these problems. “We continue to have serious safety concerns,” he said.

Meanwhile, transit advocates continued to express dismay with the way Siemens has handled its projects. “This has been an ongoing saga,” Karyl Cafiero of the Permanent Citizens Advisory Committee to the MTA, said to Haddon. “Is this fine tuning going to take a month or six months?”

At some point, CBTC is scheduled to be deployed on the 7 line as well as the L. For now though, with a $28 million contract for 64 cars looming large, the city’s subways are kicking and screaming their way into the 21st Century.

Comments

10 responses to “CBTC tests on L line a bit jerky”

  1. anonymouse

    Automated train operation is generally just not as good as a (competent) manual driver, because of the limitations of technology. A driver will tend to have a constant brake rate, easing off a bit at the very end, while the computer, being more cautious, will slow down a bit earlier, coast, then apply full brake to stop at exactly the right spot. Going from full brake to stopped is what causes the jerk, and you can see it in many automated systems including the AirTrain. And it seems that overall, this is slightly less efficient than manual driving, which is why in Moscow where they run 39-40 trains an hour on some lines, all the trains are manual, even though they have had the technology for automation for at least a couple decades now.

    Reply
    1. herenthere

      Well, all that is required is just a readjustment in research and programming. A computer can be easily programmed to “ease off” at the end.

      And didn’t you report that CBTC was abandoned by Siemens and instead developed by in-house technicians?

      Reply
      1. Benjamin Kabak

        That was the bus arrival board project. Siemens sure seems ultra unreliable for transit projects.

        Reply
    2. Alon Levy

      Russia overall has really a strong public works mentality in the public sector. The communist-era companies, even those that were nominally privatized, end up in the hands of the managers or the workers, who like any solution that involves more jobs. It won’t surprise me if Moscow Metro resists automation for the same reason the TWU does.

      Reply
      1. anonymouse

        Yet for some reason, St. Petersburg and Kharkov (and possibly other cities as well) have automation. By the way, all trains in Moscow Metro are OPTO except the ones on lines 3 and 4, which still have old style wayside signals with trip stops and no cab signals/ASC (something that I think might change soon: they changed the signal system on Line 1 not too long ago). By the way, there’s also been no interest in CBTC in Russia at all. I think they’re happy enough with the capabilities of coded track circuit fixed block signalling, and more importantly with its general reliability, which is important when you’re running 40 trains an hour.

        Reply
  2. Adam G

    There’s a reason Siemens is always the lowest bidder on transit projects. The MTA needs to disqualify them and start dealing with companies that actually intend on following through.

    Reply
  3. Cap’n Transit

    An uncomfortable jerk? On the subway?

    Reply
  4. AlexB

    Is 40 trains per hour the maximum that the best technology will allow today? Could we ever get that on the L train? Even exploding Williamsburg couldn’t fill up a train line if they are coming every one and a half minutes…

    Reply
  5. The Secret Conductor

    firstly the L train reaches speeds up to 45mph and in the tube it comes close to 60mph (this is the biggest timesaver and tends to put the train ahead of schedule by almost 2 minutes). I think that is the optimal speed considering proximity of each train station to each other.

    secondly OPTO can only really work from midnight to 5:30am due to the amount of passengers on the train (its the reason why the conductor was brought back on some Rockaway shuttles due to the beach crowd). even then people would complain about safety of having 1 person on a 8 car train. not even most cops (when its just 1) go in the last cars with 2 people on the train. then there is the problem of people riding the side of the train or falling against the train while the train is taking off.

    and totally forget about asking questions in route cause it aint happening.

    Reply
  6. Platform glitch plaguing CBTC L trains :: Second Ave. Sagas | A New York City Subway Blog

    […] time technical problems have popped up in regards to the CBTC program. Last month, I wrote about jerking motions and breaking problems aboard the CBTC trains. What is interesting this month, however, is Haddon’s […]

    Reply

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