# Take the A train? Try again in 2010. **URL:** \ **Category:** The BBQ Pit\ **Created:** [January 25, 2005, 12:30pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568 "2005-01-25T12:30:49Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![manhattan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/manhattan/32/7_2.png) [@manhattan](https://boards.straightdope.com/u/manhattan)\ **Post date:** [January 25, 2005, 3:37pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/41 "2005-01-25T15:37:01Z")
> [@SmackFu](#): > > I don’t think they have any idea what connected to what in that closet. Ding! There’s your three-to-five years right there. It’ll take them 18 months just to trace all the now-exposed and unconnected wires to the right signals. That said, I think they’re pulling a Scotty here and will be done with things faster than they’re letting on. ---
**Author:** ![bashere](https://avatars.discourse-cdn.com/v4/letter/b/779978/32.png) [@bashere](https://boards.straightdope.com/u/bashere)\ **Post date:** [January 25, 2005, 3:46pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/42 "2005-01-25T15:46:00Z")
> [@Eve](#): > > If Anna Karenina took NJ Transit, she’d be alive today. I have nothing useful to add to this thread, other than to say that I am stealing this joke and using it at every possible opportunity. Granted, I will do so as part of my continuing efforts to be kicked completely out of polite society, but I am still stealing it. I shall build a shrine in your honor in payment (and I shall keep my Dorothy Parker books there as homage) ---
**Author:** ![Eve](https://avatars.discourse-cdn.com/v4/letter/e/9e8a1a/32.png) [@Eve](https://boards.straightdope.com/u/Eve)\ **Post date:** [January 25, 2005, 4:00pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/43 "2005-01-25T16:00:43Z")
> [@bashere](#): > > I have nothing useful to add to this thread, other than to say that I am stealing this joke and using it at every possible opportunity. Thank you, dear, it’s always nice when my drive-bys don’t pass unnoticed. ---
**Author:** ![JohnBckWLD](https://avatars.discourse-cdn.com/v4/letter/j/d6d6ee/32.png) [@JohnBckWLD](https://boards.straightdope.com/u/JohnBckWLD)\ **Post date:** [January 25, 2005, 5:48pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/44 "2005-01-25T17:48:52Z")
> [@Barbarian](#): > > Some homeless guy managed to break into a high-security yet abandoned control room in the New York subway system, and started a fire to keep warm… Insert the word ‘probably’ between the words homeless and guy. The exact cause of the blaze is still just under investigation. That being said – (supposedly because I can’t provide a cite it back this up) – the MTA has a _Price-is-Right_-type ‘come on down’ policy at certain subway stations for homeless people during excessively cold / snowy weather. I’ll lay 2-1 odds that well intentioned, (probably unwritten) but boneheaded policy ends today. As pointed out by others, the 3-5 year estimate (longer than it took the build the E.S.B) is bureaucratic CYA-speak. ---
**Author:** ![matt\_mcl](https://avatars.discourse-cdn.com/v4/letter/m/7ab992/32.png) [@matt\_mcl](https://boards.straightdope.com/u/matt_mcl)\ **Post date:** [January 25, 2005, 6:07pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/45 "2005-01-25T18:07:23Z")
> [@](#): > > Thank you, dear, it’s always nice when my drive-bys don’t pass unnoticed. I noticed it too, and will also be using it at every opportunity. I will also be adding an additional clay figurine to my **Eve** altar. (If you’ve been having the sneezes lately, that’s because of that wank package of incense I got passed off. Sorry.) ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [January 25, 2005, 6:17pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/46 "2005-01-25T18:17:36Z")
> [@The New York Times](#): > > Officials said they believed that there were only two companies in the world that were able to repair the signals. One is based in Pittsburgh, and the other in Paris. My condolences if they go with Paris-based Alcatel. The Alcatel system installed a few years ago to “update” the SF Muni’s controls was a mess. The thing broke down so much that passengers would frequently pull the emergency door releases and walk through the tunnels to the next station. Going out on a limb to guess that the Pittsburgh option is Bombardier. Wabtech is also in that area, but is more focused on air brakes, hence the name - Westinghouse Air Brake Technology. Whoever gets the job is going to need at least a week, and probably closer to a month just to sift through the charred mess in that relay station to try and sort out where all the cables go. Then, more time to convert their notes and scribbles into clean wiring diagrams and specs for replacement equipment. Over the decades, I’m sure there’s been several undocumented repairs or modifications made in this room, making the tedious process of tracing everything out vital - “as designed” is immaterial here. They need to figure out the “as built.” On the bright side, once it’s done, the equipment will probably occupy a third of the space as the old stuff. Insulation back then was layers and layers of gutta-percha, rubber, fabric and paper, so wires that were as big around as your thumb can be replaced by wires the size of a pencil. ---
**Author:** ![Jenaroph](https://avatars.discourse-cdn.com/v4/letter/j/e8c25b/32.png) [@Jenaroph](https://boards.straightdope.com/u/Jenaroph)\ **Post date:** [January 25, 2005, 6:25pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/47 "2005-01-25T18:25:29Z")
> [@JohnBckWLD](#): > > Insert the word ‘probably’ between the words homeless and guy. The exact cause of the blaze is still just under investigation. Some homeless probably guy started the fire? ---
**Author:** ![Servo](https://avatars.discourse-cdn.com/v4/letter/s/49beb7/32.png) [@Servo](https://boards.straightdope.com/u/Servo)\ **Post date:** [January 25, 2005, 6:29pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/48 "2005-01-25T18:29:23Z")
> [@World Eater](#): > > It’s not exactly rocket science though. The tracks are split into chunks every 300 yards or so, and are electrically insulated from each other. When any section of a train occupies a chunk of track it completes a circuit indicating the presence of a train in it. **While this is going on, the signals react accordingly to the locations of the trains.** IIRC the system is set up so there is at least one buffer section between trains. Bolding mine. You said it in one sentence, but this is the single most complicated part of the signaling system. The tracks are broken up into blocks by insulators. The signals are designed to indicate the presence or absence of a train in its control length, which is a set number of blocks past the actual signal. Control lengths always overlap to at least the next signal, which means that a single block can be a part of multiple signals’ control lengths. Signals also need to indicate not only if there is a train in their control length or not [display red or yellow], but also if there is a train in the next signal’s control length [display yellow or green]. Add to this the concept of Grade Time and Station Time which enforce speed limits by using timers to keep a signal from clearing. The timer is either in effect all of the time because of track topology [Grade Time], or is only in effect when there is a train a certain distance ahead of them [Station Time]. There are also two different flavors of Grade Time: one-shot and two-shot. Don’t forget automatic key-by, the myriad intricacies of the interlock at switch points, the human interface to the whole thing from the towers, and on and on. The fact that it’s so old only makes it worse. These aren’t logical concepts playing out in a computer, but real, physical devices interacting with each other. The signaling system is exceedingly complex and a timeframe of a couple of years to fix doesn’t surprise me at all. With that said, I still have a very low opinion of the MTA and 5 years is more than likely a bit of scaremongering. ---
**Author:** ![D\_Odds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/d_odds/32/2882_2.png) [@D\_Odds](https://boards.straightdope.com/u/D_Odds)\ **Post date:** [January 25, 2005, 6:35pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/49 "2005-01-25T18:35:47Z")
> [@JohnBckWLD](#): > > Insert the word ‘probably’ between the words homeless and guy. The exact cause of the blaze is still just under investigation. > > That being said – (supposedly because I can’t provide a cite it back this up) – the MTA has a _Price-is-Right_-type ‘come on down’ policy at certain subway stations for homeless people during excessively cold / snowy weather. I’ll lay 2-1 odds that well intentioned, (probably unwritten) but boneheaded policy ends today. > > As pointed out by others, the 3-5 year estimate (longer than it took the build the E.S.B) is bureaucratic CYA-speak. This morning’s paper had a fairly detailed description including illustrations on how the fire started. The cause of the blaze is known; who did it is still assumed. [NY Newsday](http://www.newsday.com/news/yahoo/nyc-train0125,0,4168832.story?coll=ny-newsaol-headlines) > [@](#): > > The blaze apparently started after a homeless person entered an off-limits section of track at the station and ignited a shopping cart filled with lumber, Reuter said police told him. The fire spread to a relay room and caused “major, major damage,” he said. Website doesn’t seem to have the illustration from the paper. ---
**Author:** ![Billdo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/billdo/32/315_2.png) [@Billdo](https://boards.straightdope.com/u/Billdo)\ **Post date:** [January 25, 2005, 6:48pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/50 "2005-01-25T18:48:07Z")
As a follow-up to **Servo** ’s excellent summary of subway signalling, there is a detailed description of the New York City Subway’s signalling system [at this site](http://www.nycsubway.org/tech/signals/). Spending a bit of time there will show you why it is a complex process, particularly as everthing has to be designed in a fail-safe manner. ---
**Author:** ![World\_Eater](https://avatars.discourse-cdn.com/v4/letter/w/f04885/32.png) [@World\_Eater](https://boards.straightdope.com/u/World_Eater)\ **Post date:** [January 25, 2005, 6:49pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/51 "2005-01-25T18:49:13Z")
> [@Servo](#): > > Bolding mine. > > You said it in one sentence, but this is the single most complicated part of the signaling system. > > The tracks are broken up into blocks by insulators. The signals are designed to indicate the presence or absence of a train in its control length, which is a set number of blocks past the actual signal. Control lengths always overlap to at least the next signal, which means that a single block can be a part of multiple signals’ control lengths. > > Signals also need to indicate not only if there is a train in their control length or not [display red or yellow], but also if there is a train in the next signal’s control length [display yellow or green]. > > Add to this the concept of Grade Time and Station Time which enforce speed limits by using timers to keep a signal from clearing. The timer is either in effect all of the time because of track topology [Grade Time], or is only in effect when there is a train a certain distance ahead of them [Station Time]. There are also two different flavors of Grade Time: one-shot and two-shot. > > Don’t forget automatic key-by, the myriad intricacies of the interlock at switch points, the human interface to the whole thing from the towers, and on and on. > > The fact that it’s so old only makes it worse. These aren’t logical concepts playing out in a computer, but real, physical devices interacting with each other. > > The signaling system is exceedingly complex and a timeframe of a couple of years to fix doesn’t surprise me at all. With that said, I still have a very low opinion of the MTA and 5 years is more than likely a bit of scaremongering. Great post **Servo**. I guess it would help to know which quartermile of track was rendered inoperable. Looking at the trainmap of Chambers street doesn’t reveal anything super complicated. [http://www.nycsubway.org/maps/track/smdowntown.png](http://www.nycsubway.org/maps/track/smdowntown.png) I don’t mean to belittle the damage, but I can’t see why they shouldn’t be back up and running in a year. Perhaps some of that automated technology they’ve been testing on the L train can be integrated? Btw I thought they stopped keybys after the Williamsburg bridge accident. Only two companies in the world make train signals? Huh? I think we should call the A-team. 😛 ---
**Author:** ![LavenderBlue](https://avatars.discourse-cdn.com/v4/letter/l/e95f7d/32.png) [@LavenderBlue](https://boards.straightdope.com/u/LavenderBlue)\ **Post date:** [January 25, 2005, 7:34pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/52 "2005-01-25T19:34:52Z")
My husband’s very long commute just got longer. Whoever set the fire should be placed on the most crowded A train platform in front of a group of commuters with a sign around his neck reading “This is all my fault.” ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [January 25, 2005, 7:36pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/53 "2005-01-25T19:36:22Z")
[Looks like there’s just a handful of train control suppliers in the world.](http://www.tsd.org/cbtc/#suppliers) ---
**Author:** ![Eve](https://avatars.discourse-cdn.com/v4/letter/e/9e8a1a/32.png) [@Eve](https://boards.straightdope.com/u/Eve)\ **Post date:** [January 25, 2005, 8:13pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/54 "2005-01-25T20:13:48Z")
> [@lavenderlemon](#): > > My husband’s very long commute just got longer. Whoever set the fire should be placed on the most crowded A train platform in front of a group of commuters with a sign around his neck reading “This is all my fault.” Does anyone really believe the “mysterious homeless person” story? Everyone at my office thinks the MTA is just covering its ass. ---
**Author:** ![Eleusis](https://avatars.discourse-cdn.com/v4/letter/e/f4b2a3/32.png) [@Eleusis](https://boards.straightdope.com/u/Eleusis)\ **Post date:** [January 25, 2005, 11:10pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/55 "2005-01-25T23:10:32Z")
> [@Cheesesteak](#): > > I suspect that whoooshing noise isn’t the A train going by. Thank you. ---
**Author:** ![Beware\_of\_Doug](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Beware\_of\_Doug](https://boards.straightdope.com/u/Beware_of_Doug)\ **Post date:** [January 25, 2005, 11:29pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/56 "2005-01-25T23:29:59Z")
> [@Metacom](#): > > Coming up with a custom computerized control instrument that’s going to be interfaced to stuff designed in the 30’s and that’s going to be situated in a tough environment (heat, vibration, humidity, etc.) is gonna involve circuit designers, software designers, whoever-the-people-are-who-design-cabinet-enclosures, etc. And more than likely (this being New York) at least one autistic savant transit buff in very high-water black chino pants and 1970s-style serial-killer glasses frames. ---
**Author:** ![TheLoadedDog](https://avatars.discourse-cdn.com/v4/letter/t/35a633/32.png) [@TheLoadedDog](https://boards.straightdope.com/u/TheLoadedDog)\ **Post date:** [January 25, 2005, 11:37pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/57 "2005-01-25T23:37:55Z")
All that said, it’s still a “simple” block control system used by railways all over the word (and now being superceded by other technology). I don’t believe it’s a case of having to reverse engineer to find out what the old technology did. We _know_ what it did. All they have to do is keep trains apart. This is indeed complex technology, but it is very much _known_ technology. Heck they could almost\* buy an off-the-shelf product from another city’s subway system. That thing’ll be back up within twelve months. \*Yes, railfans, I did say “almost”. I know it’s not quite as simple as that. ---
**Author:** ![Muffin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/muffin/32/4341_2.png) [@Muffin](https://boards.straightdope.com/u/Muffin)\ **Post date:** [January 25, 2005, 11:45pm UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/58 "2005-01-25T23:45:56Z")
> [@gotpasswords](#): > > On the bright side, once it’s done, the equipment will probably occupy a third of the space as the old stuff. Hey, more space for homeless people to use. ---
**Author:** ![manhattan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/manhattan/32/7_2.png) [@manhattan](https://boards.straightdope.com/u/manhattan)\ **Post date:** [January 26, 2005, 1:11am UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/59 "2005-01-26T01:11:53Z")
> [@Eve](#): > > Does anyone really believe the “mysterious homeless person” story? Everyone at my office thinks the MTA is just covering its ass. I buy it. I don’t put it past the MTA to tell a whopper, but the fire department is pretty good about that kind of stuff. ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [January 26, 2005, 1:52am UTC](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568/60 "2005-01-26T01:52:51Z")
> [@gotpasswords](#): > > Going out on a limb to guess that the Pittsburgh option is Bombardier. Wabtech is also in that area, but is more focused on air brakes, hence the name - Westinghouse Air Brake Technology. I really have to advise _against_ ever using Wabtech’s stuff. You see, [Pete Puma’s](http://boards.straightdope.com/sdmb/showthread.php?t=280593) pretty much in charge of the parts we make for them. :eek: :eek: :eek: [Previous page](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568.md?page=2) [Next page](https://boards.straightdope.com/t/take-the-a-train-try-again-in-2010/286568.md?page=4)