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New York Computerizes its Subway System
Iphtashu Fitz writes "New York City's Metropolitan Transit Authority launched it's first fully computer controlled subway line this month. The `L' Line of the MTA that connects the southern part of Manhattan with Brooklyn was picked for this pilot program because of its relatively short length and the fact that it doesn't share tracks with any other lines. Trains on this line no longer have conductors on board, and only a single driver in the front to monitor all the systems.
What's the big deal, you may ask? After all, cities like San Francisco and Paris already have computerized subway lines. Well, having recently celebrated its 100th anniversary the MTA is one of the oldest subway systems in the United States, and one of the largest in the world. If all goes well, the MTA will continue to expand automated service to the rest of the subway system over the next 20 years. But just how safe and secure will these new automated lines be? The radio links that provide data communication between the trains and the control center are encrypted, but how long until a hacker manages to crack it?"
In New York, train dwell times--time spent in stations--can be frustratingly long, especially during rush hours. Besides people pushing and shoving to get on the train, you've also got the jokers who hold the doors for their friends who're still running down the stairs.
Without a conductor, who's going to yell at everyone to stop holding the doors? How does this work in other automated systems, like Paris's Météor?
seems that recently a portion of the subway burnt down and when the guys went down to repair it they found that the hardware driving the system dated back to the 1930's. After more digging they found that the original systems laid in the early 1900's till 1920 were still operating and actually in daily use in many other parts of the subway. point is that thing is working well that they dont want to touch the thing. the other fact is that there is no way they are going to get the thing changed without majorly affecting the daily workings of the system.
Trains on this line no longer have conductors on board
I dunno about the rest of you, but I want a conductor on the train. Things like having a human look outside the train to make sure nobody is about to get on when the doors close, having someone on the train in case of an emergancy, having someone on the train that is a detterent to crime (just imagine, would a would-be rapist be more or less likely to rape a woman if a conductor was walking up and down the cars).
And part of me feels bad for the guy losing the job, the conductor.
Continue reading the news story:
To have a truly integrated system, the city would have to continue buying all its equipment from Siemens AG, effectively giving it a monopoly.
This also raises a red flag. One company that will in effect control the whole parts system? How can we know we won't get hosed with the price?
Even if they do autimate, lets keep the conductor. Someone who knows how the train runs. Someone who can over-ride the computers if needed. Every vessel needs her captin.
Rosco: "If brains were gunpowder, Enos couldn't blow his nose."
What the MTA really needs to do is publish realtime subway position info. On billboards in the stations, on their website, on automated phone lines, as a pager/sms subscription/request service. Millions of us use it daily, wasting millions of hours of America's most productive workforce as we wait for trains, miss express connections, clog stations. The uncertainty keeps many people using cars and taxis, which make the roads even worse. Automating subways will save a few million a year in conductor costs, out of an $8B budget, which will be lost every day in the productivity of our workers. But I guess MTA contractors don't get a cut of the productivity gains from sensible priorities. Thanks Mayor Bloomberg, and Governor Pataki (who controls the MTA), and Sir Giuliani, who blew the only real chance of taking the subway back from the state for the people who it actually serves.
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make install -not war
People have tried to hack the metrocard system for years. The closest they came was a decidedly non-l33t solution involving demagnetising part of the strip relating to card expiration date. It gave access for a week, only because they MTA had the system set for "be generous". Some NYers, led by the local tabloid "The Daily News" tend to be moderate to extremely luddite when it comes to technology, and the metrocard was not welcomed with open arms. When it was first released the MTA went to great lengths to ensure that no one felt the metro card system was "ripping them off". So rather than properly rejecting expired cards (that may have had money on them, you see), they let them through. Some smartass realised that by erasing the part of the strip that contained the expiration date, the reader would automatically decide the card was expired. Since the system was set to ignore that on initial release, they got through. Once the exploit got out, they stopped it, iirc within 3 days of the first occurance (the system tracks this too, you see).
Things have changed since then, and in light of a recent subway fire that caused great inconvenience, NYers have gone the other way, wishing that the entire system was computerized. Yea, even the Daily News quite vociferously raised the cry for greater computerization in the MTA switching network.
The MTA is underfunded but not stupid or poorly run. The system is well designed and the underlying databases are also redundant and protected. The hardest part of the job for them is getting funding approved for their various efforts, they usually do a good job of executing once they get it. They've worked quite hard on this new system, it'll be a step forward in spite of the pundits.
This is an incredibly detailed simulator, going all the way down to the relay level. You can work the control panels, look at the relay schematics, and see the signals from the train operator's perspective in OpenGL.
The system simulated, developed by General Railway Signal in the 1940s, is the first "intelligent user interface" ever developed. There were many earlier signal systems, and by 1914 or so they were routinely interlocked against operator errors for safety. But this one, NX, for "entry-exit" signalling, was the first one that offered intelligent assistance to the signal operator.
The train dispatcher selects a train entering a junction full of switches, signals, and trains. The NX system will then light up all the currently valid "exits", places the train can exit the junction, checking for conflicts with other trains and timing constraints. When the operator selects an "exit", with one button push, the NX system does everything else. It sets the track switches, verifies that they're in position and locked, turns the appropriate signals green, lowers the appropriate train stops (alongside the track are mechanical devices that, if raised, will be hit by an air brake valve on any passing subway car, bringing the train to a stop), and tracks the train as it moves through the junction. As the train clears each signal, switch or crossover, that resource is released so another train can use it.
The train stops come back up behind each train (and the signalling system verifies that they do so), so that separation between trains is maintained. Even speed control is enforced. There are timers all through the system, so that when a train passes one signal, there's a minimum time before it can pass the next one. An overspeeding train will be tripped and stopped.
It's all done with relays. Big relays, with silver contacts to prevent corrosion. It's fail-safe in a formal sense - no relay coil failure, power failure, or broken wire will result in an unsafe condition. Everything is designed to "fail to red". The designers trusted gravity and solid metal, and not much else.
Situations programmer types never think of are handled. For example, a train stop might become jammed due to ice. That's not only detected, it's handled properly. If a train stop protecting a switch won't go to the up (stop) position, the signalling system won't let the switch move. (And the gear is rugged enough that when someone goes out with a blowtorch to unfreeze the thing, it will be unharmed.)
This is a very safe technology. But it requires a huge, highly trained maintenance force.