"the majority [of heat comes] from the train hitting the brakes as it pulls into the station, an intense friction that gives off an exorbitant amount of warm air."
I wonder if regenerative brakes can be installed (or are already installed...)
All of the newer “NTT” cars have regenerative braking[1]. NTT cars make up, as far as I can tell, the majority of current revenue-service rolling stock[2] (but there’s still a lot of older cars in-service).
Seems like they'd keep heat from the train from making its way onto the platform. And if platforms are air-conditioned, they'd keep that air from escaping into the tunnels.
Doors only work if they can line up with every single train that services said platform. Unfortunately, not all trains share door positions, and most platforms will see a mixed fleet of trains. The new trains have consistent door positioning, but the old ones are still in good working order and aren't due for retirement until late 2020s-early 2030s.
It is still doable, you can start by splitting the running stock by similarly aligned doors run them on few line and start with the few lines which are now already aligned.
Realistically by the time you are even close to half the 470 stations it will be late 2020's anyway. Then you can aim for full coverage as the stock is deprecated.
It is more likely the $1-2 million per station cost is not high priority as say CBTC which will improve revenue as it increases capacity.
The problem is that none of the lines except two of them are separated enough. Separating them to the degree required for this to work is not possible, because the crazy interlining is the only way to provide many trips in a patchwork system that was originally three competing subways; many transfers would not be available, and the remaining ones would not be able to handle the resulting transfer volume. It would also not be desirable, because right now reroutes are commonly used to maintain service in case of problems or maintenance; doors restricting fleets to lines would reduce operational flexibilty.
The problem is also too large to segregate. We are talking about a third of the current fleet that is not compatible with new train door placements. Even after the oldest of these are retired with projected future train orders, it will be about a tenth of the fleet, larger than the entire Boston T rapid transit fleet.
Maybe this could be solved by having platform doors that open in all the required positions?
You could either add extra platform doors or make platform doors that are wider than the train doors and open part way to match the train.
Unfortunately, if cars have different lengths, it increases permutations a lot. But you could handle even that by building a wall made entirely of doors (staggered on two door tracks), so the gap between any two doors can open up to any desired width.
One neat, low techregenerative braking system used in some places is having the stations built slightly higher than the rest of the network. As the train comes into the station, the slope helps it slow down, and then when it leaves the station, the slope helps it accelerate. Never underestimate the energy stored by moving a fully laden train a few centimetres up.
Curious to hear from someone who may know more about HVAC than me:
Why don’t subway stations simply install giant industrial mini-spit-style air conditioners in these stations? It doesn’t seem particularly hard to rout a few dozen tubes of coolant down to a station while keeping the compressor and expelling heat outside.
> It doesn’t seem particularly hard to rout a few dozen tubes of coolant down to a station while keeping the compressor and expelling heat outside.
It's hard when you're spending $90.4M to install 3 elevators.
That said, while mostly it's just an annoyance, the heat really is a hazard at a handful of stations; people are regularly blacking out at union square while waiting for the L.
The ducts get very large, so trying to fit them in existing infrastructure is a big challenge. Also consider that much of original 'spare' space has been repurposed for additional systems (CCTV, PA, additional power etc).
It's different for new infrastructure where this can be allocated more readily at a smaller marginal cost.
Air conditioning in a large, unenclosed space is quite costly and inefficient. Stations typically have passive ventilation (in most NYC stations along most of the length of the platform, plus entrances). And then there’s the massive tunnel that lies between stations. The London Underground (which is referenced in the article) did a lot of things, but they didn’t try to air condition the stations. They did in-station air circulation, active ventilation from surface air, heat exchange cooling from existing cool water sources, and heat re-capture to heat homes.
Then, of course, more specific to NYC, is that it’s more worthwhile presently to spend money on making the trains run more smoothly (whereby passengers will spend less time in the station), as the system has major issues there (and not enough money as-is).
> giant industrial mini-spit-style air conditioners
With mini-splits, the piping carries refrigerant (which actively participates in the thermodynamic cycle, rather than just being a simple heat exchange fluid), but the problem is that you need quite exacting standards for the air-tightness of the system, the materials used, and the pressures can be quite high. Also, combining multiple refrigeration units is...tricky.
Usually the way industrial-scale cooling/refrigeration is done is with devices called "chillers", in which all the refrigerant is entirely captive inside the chiller unit, and all you do with the chiller is hook it up to a supply of cooling water to dump heat into (or directly expose it to outside air), and you feed it water that it will cool down. Also give it an electricity hookup.
You then use the chilled water to cool down whatever you want. The advantage is that you've reduced the problem to just moving around water -- which isn't a mixture of multiple exotic fluorocarbons and compressor lube oil with special handling needs, it's just bloody water (don't drink it though, there's all sorts of dissolved metals and antifreeze and biocides).
Modern chillers are wonders of engineering, some even have active magnetic bearings that levitate the moving parts with fancy diagnostic/instrumentation systems that can tell you, to the micrometer, the position of the levitated shaft (not kidding, http://cgproducts.johnsoncontrols.com/yorkdoc/160.78-o2.pdf page 37).
But yes, it's absolutely possible to do what you suggest, it's just that you'd end up moving chilled water and not refrigerant.
20 years ago, the MTRC in Hong Kong started to install platform screen doors to seal off the platforms and reduce their air conditioning bill as most of the cool air was of course just going into the tunnels.
That investment paid for itself within a few years.
Evacuating the heat from the train is another issue that must be addressed but it’s far from being an unaddressable one and there are already many examples of other cities implementing workable solutions.
Having doors installed along the platform has a number of advantages beside air conditioning: increased safety (no more suicides and accidents), more platform capacity since people can get right to the edge of the platform, potential increase in network capacity since trains can enter the station faster as they don’t have to slow down early to enter the platform at low speed to avoid passengers accidents.
Older networks like London, Paris and New York have a much harder time implementing these measures as they are often very deep and their infrastructure are old and quite vast, but they each have projects to tackle these issues, although in the case of New York, the cost will probably slow down adoption (not least because of the crazy Union requirements).
The problem with doors in New York in particular is that not all generations of rolling stock have doors in the same location. Unlike MTRC, where one line has its own rolling stock and there is no interoperation between different lines, many services, each with different door positions, can utilize the same platforms. And basically the only way to have a door configuration compatible with all rolling stock is to not install any doors at all.
You could replace the rolling stock, but all of it is in good operating condition, and the last of the oldest cars with non-compatible doors would be retired in the 2030s.
Air conditioning is also a huge challenge; traditionally, New York's subway has been cooled using the piston effect of trains, with frequent grates open to the surface to draw in air. With air conditioning those large, frequent openings are now a curse.
The separate fleets are assigned to individual lines (which are better thought of as services). But there are 36 of them, pretty much all of which interweave with each other. The R, for example, at some point shares track with the N, the W, and the M, which in turn share track with the Q, the D, and the F, which in turn share track with the E, the B, the G, and so on and so forth. And this is before we consider the fact that in New York, trains are often rerouted due to service changes onto tracks they don't normally serve, and sometimes are changed after years of change in ridership patterns; installing platform doors incompatible with certain trains would reduce operational flexibility.
Untangling the lines is not possible, partially because the system was designed to provide as many one seat rides as possible, and partially because the current subway is a patchwork mashup of three separate, competing subway systems; if you were to separate the lines, some trips would just not be possible via transfers, and most transfer complexes would not be able to handle the amount of passengers changing trains.
To answer how many cars are not compatible, that would be 2025 subway cars out of a total of 6148 (at least according to Wikipedia.) Of these, 625 were built in the late '80s and are not due for retirement til the 2030s. To put that in perspective, the late '80s fleet is bigger than the entire Boston T rapid transit fleet (Green and Silver Lines not withstanding)
So about a third of the fleet is incompatible right now. I assume the problem is equally bad in both A division and B division (fat trains and thin trains for those reading along).
The track sharing doesn't seem like a huge deal in my proposal. Services usually don't share track across trunk lines. I can't think of any platforms that are shared by trains on different trunks. As an example you could probably get away with enforcing A/C/E are new cars only. Worst case you delay installing the barriers on the shared track segments. There's also the obvious solution of using the L and G as the system test case (yet again). MTA should take the opportunity while the L is shut down anyway for the Canarsie tunnel repair clusterfudge.
You're right that it would reduce operational flexibility a bit. In theory service reroutes should be uncommon enough for this to not matter. But you and I know better. If I were to draft this as a serious proposal I'd look at reroute probabilities, come up with some way to estimate the cost incurred by inflexibility, and optimize the installation of platform walls to balance this cost constraint.
> I can't think of any platforms that are shared by trains on different trunks.
* 2/5 - Flatbush in Brooklyn, White Plains Road in the Bronx
* E/F, M/R - Queens Blvd
* A/B/C/D - Central Park West
* F/G - Culver
* B/D/N/Q - South Brooklyn
* J/M/Z - Broadway (Brooklyn)
> There's also the obvious solution of using the L and G as the system test case (yet again).
The L was considered for a platform door pilot during the shutdown. It was shelved in favor of bringing full accessibility to Union Square. IMO platform doors are quite far down the list for things that we could spend billions of dollars on, rather than full accessibility, or speeding up CBTC, or what have you, especially given the complexity vs benefit ratio.
you win today's subway knowledgeablity test and get +50 authentic New Yorker points. You may cash these points in at any Duane Reade for assorted prizes including a "get out of Time Square or Jail free" card.
The IRT and BMT Eastern Division all use cars that have doors at the same place, so that's not an excuse to not try platform doors. You could make the test station one of the L train stations that's going to be closed for two years and install them at a super leisurely pace. (The L is basically completely isolated from the rest of the system, and already requires special rolling stock for CBTC. And it's going to be closed for two years for other repairs.)
Even if varying door locations were the problem... Tokyo has many lines that share rolling stock among 3 or even 4 separate rail companies, and they still have platform doors. There are just a lot more doors in the station than on each train.
There simply is no interest or money for platform doors in NYC. Even though people fall onto the tracks and are killed, even though many stations suffer from capacity problems because there aren't enough safe places to stand, even though people holding train doors delays every train multiple minutes a day... we're simply allergic to the concept. I've never even heard it seriously proposed.
The major IRT lines save for the 7 operate mixed fleets of NTT and R62/A equipment, none of which share door positions IIRC. The Eastern Division still uses old rolling stock like R42s from time to time. The last time they tried getting rid of cars prematurely, the R179 order came in late and they were forced to run what cars remained had more aggressively, degrading reliability.
> You could make the test station one of the L train stations that's going to be closed for two years and install them at a super leisurely pace. (The L is basically completely isolated from the rest of the system, and already requires special rolling stock for CBTC. And it's going to be closed for two years for other repairs.)
This actually was a proposal. It was recently killed in favor of bringing elevators to Union Square, a major subway complex that is not ADA accessible. Which is really why they haven't caught on as a serious engineering proposal; the list of things that would be much better value for money is long, such as systemwide ADA accessibility, CBTC signalling, replacement of rolling stock, refurbishment of dilapidated, water-damaged stations, etc. You could easily come up with $50B worth of upgrades, extensions, etc. before platform doors became a priority. And they're not even that feasible.
> There are just a lot more doors in the station than on each train.
Got a source for this? This is intriguing because I've never heard of something like this. But this also introduces the complexity that the right doors have to open at the right time, lest a blind person walk into a gap between trains and die. Which is a lot to ask from an agency that can barely maintain something as mundane as elevators and escalators.
"But this also introduces the complexity that the right doors have to open at the right time, lest a blind person walk into a gap between trains and die. Which is a lot to ask from an agency that can barely maintain something as mundane as elevators and escalators."
Without any doors, nothing stops people from walking into a gap between trains and dying. So adding doors (even too many doors) isn't going to make the situation any worse. It'll make it better because there will be fewer gaps, even with too many doors all opening at once.
> The major IRT lines save for the 7 operate mixed fleets of NTT and R62/A equipment, none of which share door positions IIRC
Do they not? The R62 and R142 cars are both the same number of doors and of the same length [1] [2], and the moving platforms at some stations would, I think, require the doors be in approximately the same spot, no?
> The Eastern Division still uses old rolling stock like R42s from time to time.
Yes, but the R42 and R143/R160 have the same overall length and door count (and the spacing appears to be the same as well) [3] [4]
As an aside: it’s quite frustrating that the measurements given on the datasheets are of varying frequency.
I read this as “IRT Eastern Division and BMT Eastern Division”, and was very confused what the IRT Eastern Division was, but I think you mean all of the IRT? Indeed, the IRT (except R188) would require similar door locations already because of the moving platforms at some stations.
> I've never even heard it seriously proposed.
There were apparently budgeted funds in the 2014 Capital Plan [1], but it was just designs.
How about just using large strip curtains? Hang them from the ceiling and people can just push through them where the carriage doors stop. Should be cheap to install too.
That would neither really restrict airflow to the point where AC would be feasible, or prevent passengers from falling onto the tracks. Not sure what that would solve as a problem.
The large heavy strip curtains would restrict airflow, especially ones that are attached top and bottom. Yes they wouldn't stop people falling on the tracks, but a least they could be installed without costing billions.
One option is to increase the distance between the train and the doors, so that there's enough of a "vestibule" for people to move around in when a mismatch occurs.
I have seen platform doors arranged like what you described at an inter-city railway station. Unfortunately this is unlikely to work for hot and gross subway systems like the NYC subway, where platforms tend to be narrow and overcrowded.
Every time there's some cool thing shown somewhere in the world, you have people telling excuses why it can't be done where they live.
Close to the NIH synfrome but not quite the same.
There are some valid concerns, but I often feel the first reaction tends to be quite negative.
Maybe it doesn't make a comment people feel would be worth writing to say "great, let's do that here too!"
The biggest problem is indeed cost. Installing platform doors on the platforms throughout the system has been estimated in the past at US$1 million per station (US$400–500 million) in 2012 [1] and US$1 billion in 2013 [2]. But those estimates seem incredibly low now given more recent per-station costs elsewhere (CA$10 million, €2.6 million) [3], and the fact that NYC subway construction is higher than most other major cities [4]. As for depth, most NYC subway stations are directly below the street.
I’d be surprised if NYC builds platform doors before Communications-Based Train Control (CBTC).
Yes, and I mentioned that (and the same article) in my post :). But even if you ignore NYC being more expensive, the more recent estimated per-station prices in Paris and Montreal would come to around US$1.5–3 billion for all of NYC’s stations. If NYC remains around 6x the price in Paris, then that’s around US$9 billion for platform doors in NYC.
Anyone who has taken the subway (MRT) in Singapore knows that stations definitely don't need to hot and gross. It maybe different because we don't need full HVAC but rather only air conditioning, but taking public transport has only ever been pleasant (except when it breaks down).
Maybe some principles can be applied to other subway systems?
Regarding the heat generated from braking. I was surprised to find out that in our (very small) subway system the stations are higher than the rest of the track. This slows down the train as it is approaching the station and helps it regain speed when it leaves the station. A quite obvious idea, but must admit I might have not thought about it.
In some cities they are building district cooling [1] (comparable to district heating). Might be quite a difficult solution in densely built areas of course.
I would assume the incline would be impossible without seeing the horizon, because the car also accelerates.
I guess you mean the increased gravity feeling at the bottom of the track?
Right. I traveled once on a long-distance bus line that acted like a zero-gravity plane for a split second, as it went over a bump in the road. Just wondering if the experience would be comparable :)
The Central Line in London has some of its stations designed in this way, and you can certainly feel the slope when the train enters or leaves the station.
After riding the Central Line frequently for one year I got used to that feeling and start to think that there is something missing when I ride other lines...
The other day I calculated that the subway trains in Warsaw must give off as much heat during braking as a 70-100kW heater working continuously.
And that's a conservative estimate given that I assumed the interval between trains going a given way to be 5 minutes - during the rush hour they're twice as frequent.
Not to mention the collective body heat of a few hundred people waiting on the station which is (!) of the same order.
NYC city subway is one of the low points of the city.
On the other hand, it has this cinematic charm that I like as a tourist. But if I was going to work everyday and seeing this neglect, I'd rather had some renovations done.
52 comments
[ 5.2 ms ] story [ 131 ms ] threadI wonder if regenerative brakes can be installed (or are already installed...)
[1] http://web.mta.info/nyct/facts/ffenvironment.htm
[2] http://www.thejoekorner.com/carassignments/index.html
https://en.wikipedia.org/wiki/Platform_screen_doors
Seems like they'd keep heat from the train from making its way onto the platform. And if platforms are air-conditioned, they'd keep that air from escaping into the tunnels.
And of course they can also help with safety.
Realistically by the time you are even close to half the 470 stations it will be late 2020's anyway. Then you can aim for full coverage as the stock is deprecated.
It is more likely the $1-2 million per station cost is not high priority as say CBTC which will improve revenue as it increases capacity.
The problem is also too large to segregate. We are talking about a third of the current fleet that is not compatible with new train door placements. Even after the oldest of these are retired with projected future train orders, it will be about a tenth of the fleet, larger than the entire Boston T rapid transit fleet.
You could either add extra platform doors or make platform doors that are wider than the train doors and open part way to match the train.
Unfortunately, if cars have different lengths, it increases permutations a lot. But you could handle even that by building a wall made entirely of doors (staggered on two door tracks), so the gap between any two doors can open up to any desired width.
Why don’t subway stations simply install giant industrial mini-spit-style air conditioners in these stations? It doesn’t seem particularly hard to rout a few dozen tubes of coolant down to a station while keeping the compressor and expelling heat outside.
It's hard when you're spending $90.4M to install 3 elevators.
That said, while mostly it's just an annoyance, the heat really is a hazard at a handful of stations; people are regularly blacking out at union square while waiting for the L.
It's different for new infrastructure where this can be allocated more readily at a smaller marginal cost.
Then, of course, more specific to NYC, is that it’s more worthwhile presently to spend money on making the trains run more smoothly (whereby passengers will spend less time in the station), as the system has major issues there (and not enough money as-is).
With mini-splits, the piping carries refrigerant (which actively participates in the thermodynamic cycle, rather than just being a simple heat exchange fluid), but the problem is that you need quite exacting standards for the air-tightness of the system, the materials used, and the pressures can be quite high. Also, combining multiple refrigeration units is...tricky.
Usually the way industrial-scale cooling/refrigeration is done is with devices called "chillers", in which all the refrigerant is entirely captive inside the chiller unit, and all you do with the chiller is hook it up to a supply of cooling water to dump heat into (or directly expose it to outside air), and you feed it water that it will cool down. Also give it an electricity hookup.
You then use the chilled water to cool down whatever you want. The advantage is that you've reduced the problem to just moving around water -- which isn't a mixture of multiple exotic fluorocarbons and compressor lube oil with special handling needs, it's just bloody water (don't drink it though, there's all sorts of dissolved metals and antifreeze and biocides).
Modern chillers are wonders of engineering, some even have active magnetic bearings that levitate the moving parts with fancy diagnostic/instrumentation systems that can tell you, to the micrometer, the position of the levitated shaft (not kidding, http://cgproducts.johnsoncontrols.com/yorkdoc/160.78-o2.pdf page 37).
But yes, it's absolutely possible to do what you suggest, it's just that you'd end up moving chilled water and not refrigerant.
Evacuating the heat from the train is another issue that must be addressed but it’s far from being an unaddressable one and there are already many examples of other cities implementing workable solutions.
Having doors installed along the platform has a number of advantages beside air conditioning: increased safety (no more suicides and accidents), more platform capacity since people can get right to the edge of the platform, potential increase in network capacity since trains can enter the station faster as they don’t have to slow down early to enter the platform at low speed to avoid passengers accidents.
Older networks like London, Paris and New York have a much harder time implementing these measures as they are often very deep and their infrastructure are old and quite vast, but they each have projects to tackle these issues, although in the case of New York, the cost will probably slow down adoption (not least because of the crazy Union requirements).
You could replace the rolling stock, but all of it is in good operating condition, and the last of the oldest cars with non-compatible doors would be retired in the 2030s.
Air conditioning is also a huge challenge; traditionally, New York's subway has been cooled using the piston effect of trains, with frequent grates open to the surface to draw in air. With air conditioning those large, frequent openings are now a curse.
Just shove all the old trains on a single line for now and install the platform doors on that line in the 2030s.
Untangling the lines is not possible, partially because the system was designed to provide as many one seat rides as possible, and partially because the current subway is a patchwork mashup of three separate, competing subway systems; if you were to separate the lines, some trips would just not be possible via transfers, and most transfer complexes would not be able to handle the amount of passengers changing trains.
To answer how many cars are not compatible, that would be 2025 subway cars out of a total of 6148 (at least according to Wikipedia.) Of these, 625 were built in the late '80s and are not due for retirement til the 2030s. To put that in perspective, the late '80s fleet is bigger than the entire Boston T rapid transit fleet (Green and Silver Lines not withstanding)
So about a third of the fleet is incompatible right now. I assume the problem is equally bad in both A division and B division (fat trains and thin trains for those reading along).
The track sharing doesn't seem like a huge deal in my proposal. Services usually don't share track across trunk lines. I can't think of any platforms that are shared by trains on different trunks. As an example you could probably get away with enforcing A/C/E are new cars only. Worst case you delay installing the barriers on the shared track segments. There's also the obvious solution of using the L and G as the system test case (yet again). MTA should take the opportunity while the L is shut down anyway for the Canarsie tunnel repair clusterfudge.
You're right that it would reduce operational flexibility a bit. In theory service reroutes should be uncommon enough for this to not matter. But you and I know better. If I were to draft this as a serious proposal I'd look at reroute probabilities, come up with some way to estimate the cost incurred by inflexibility, and optimize the installation of platform walls to balance this cost constraint.
* 2/5 - Flatbush in Brooklyn, White Plains Road in the Bronx
* E/F, M/R - Queens Blvd
* A/B/C/D - Central Park West
* F/G - Culver
* B/D/N/Q - South Brooklyn
* J/M/Z - Broadway (Brooklyn)
> There's also the obvious solution of using the L and G as the system test case (yet again).
The L was considered for a platform door pilot during the shutdown. It was shelved in favor of bringing full accessibility to Union Square. IMO platform doors are quite far down the list for things that we could spend billions of dollars on, rather than full accessibility, or speeding up CBTC, or what have you, especially given the complexity vs benefit ratio.
Even if varying door locations were the problem... Tokyo has many lines that share rolling stock among 3 or even 4 separate rail companies, and they still have platform doors. There are just a lot more doors in the station than on each train.
There simply is no interest or money for platform doors in NYC. Even though people fall onto the tracks and are killed, even though many stations suffer from capacity problems because there aren't enough safe places to stand, even though people holding train doors delays every train multiple minutes a day... we're simply allergic to the concept. I've never even heard it seriously proposed.
> You could make the test station one of the L train stations that's going to be closed for two years and install them at a super leisurely pace. (The L is basically completely isolated from the rest of the system, and already requires special rolling stock for CBTC. And it's going to be closed for two years for other repairs.)
This actually was a proposal. It was recently killed in favor of bringing elevators to Union Square, a major subway complex that is not ADA accessible. Which is really why they haven't caught on as a serious engineering proposal; the list of things that would be much better value for money is long, such as systemwide ADA accessibility, CBTC signalling, replacement of rolling stock, refurbishment of dilapidated, water-damaged stations, etc. You could easily come up with $50B worth of upgrades, extensions, etc. before platform doors became a priority. And they're not even that feasible.
> There are just a lot more doors in the station than on each train.
Got a source for this? This is intriguing because I've never heard of something like this. But this also introduces the complexity that the right doors have to open at the right time, lest a blind person walk into a gap between trains and die. Which is a lot to ask from an agency that can barely maintain something as mundane as elevators and escalators.
Without any doors, nothing stops people from walking into a gap between trains and dying. So adding doors (even too many doors) isn't going to make the situation any worse. It'll make it better because there will be fewer gaps, even with too many doors all opening at once.
Do they not? The R62 and R142 cars are both the same number of doors and of the same length [1] [2], and the moving platforms at some stations would, I think, require the doors be in approximately the same spot, no?
> The Eastern Division still uses old rolling stock like R42s from time to time.
Yes, but the R42 and R143/R160 have the same overall length and door count (and the spacing appears to be the same as well) [3] [4]
As an aside: it’s quite frustrating that the measurements given on the datasheets are of varying frequency.
[1] https://www.nycsubway.org/perl/caption.pl?/img/cars/sheet-r6...
[2] https://www.nycsubway.org/perl/caption.pl?/img/cars/sheet-r1...
[3] https://www.nycsubway.org/perl/caption.pl?/img/cars/sheet-r4...
[4] https://www.nycsubway.org/perl/caption.pl?/img/cars/sheet-r1...
In R62s, doors are parallel to each other on each side of the car. [1]
However, it was found that because passengers like to crowd at doors, passengers wishing to exit from either side would just crowd in the same place.
To ease crowding, the NTTs have wider, offset doors, so that not everybody is standing in the same place [2]
The gap fillers at Union Square are very long, which is why they can line up with multiple door positions. [3]
[1] - https://en.wikipedia.org/wiki/R62_(New_York_City_Subway_car)...
[2] - https://en.wikipedia.org/wiki/R142A_(New_York_City_Subway_ca...
[3] - https://i.ytimg.com/vi/rHyfbrJ8ge4/maxresdefault.jpg
I read this as “IRT Eastern Division and BMT Eastern Division”, and was very confused what the IRT Eastern Division was, but I think you mean all of the IRT? Indeed, the IRT (except R188) would require similar door locations already because of the moving platforms at some stations.
> I've never even heard it seriously proposed.
There were apparently budgeted funds in the 2014 Capital Plan [1], but it was just designs.
[1] http://web.mta.info/capitaldashboard/allframenew_head.html?P...
There are some valid concerns, but I often feel the first reaction tends to be quite negative.
Maybe it doesn't make a comment people feel would be worth writing to say "great, let's do that here too!"
I’d be surprised if NYC builds platform doors before Communications-Based Train Control (CBTC).
[1] https://www.wnyc.org/story/283792-nyc-mta-tepidly-explores-p...
[2] https://www.nytimes.com/2013/01/29/nyregion/mta-says-subway-...
[3] https://www.thetransportpolitic.com/2017/09/26/the-case-of-t...
[4] https://www.nytimes.com/2017/12/28/nyregion/new-york-subway-...
https://www.nytimes.com/2017/12/28/nyregion/new-york-subway-...
Maybe some principles can be applied to other subway systems?
In some cities they are building district cooling [1] (comparable to district heating). Might be quite a difficult solution in densely built areas of course.
[1] https://en.wikipedia.org/wiki/District_cooling
After riding the Central Line frequently for one year I got used to that feeling and start to think that there is something missing when I ride other lines...
And that's a conservative estimate given that I assumed the interval between trains going a given way to be 5 minutes - during the rush hour they're twice as frequent.
Not to mention the collective body heat of a few hundred people waiting on the station which is (!) of the same order.
China's subways are all air-conditioned.
On the other hand, it has this cinematic charm that I like as a tourist. But if I was going to work everyday and seeing this neglect, I'd rather had some renovations done.