Oct
04

A look at the 20 Year Needs: Articulated trains

By

The open gangway of an articulated train in Paris.

I haven’t been to Paris in a while. My one and only trip to the City of Light came in 2001, and even then, I remember riding articulated train sets on the Metro. To a city rat who hadn’t experienced too many other subway systems, these seemingly endless trains were a revelation. They seemed — and were — more spacious than New York’s limited cars and allowed for better passenger flow and more people to ride with a little bit of extra comfort. Why didn’t New York have these, I’ve often wondered.

Over the years, we’ve heard a variety of excuses emanating from any number of U.S. transit agencies. While we have articulated buses, trains with open gangways haven’t yet arrived in the states. Some say that articulated trains can’t handle New York’s curves; others say that it’s a new thing requiring extensive testing. Whatever the reason, we sacrifice capacity and flexibility for the rolling stock we have.

But the MTA seems to be considering articulated trains as they look to the future. In the 20 Year Needs Assessment released this week, articulated make an appearance. Buried in the back as part of the effort to develop a 21st Century system was the following:

As the MTA continues to purchase new buses and subway and commuter rail fleets, it must incorporate state-of-the-art design concepts and technologies to minimize energy consumption, maximize carrying capacity, reduce loading times, and meet the expectation of a tech-savvy generation of new travelers. In particular, consideration should be given to trainsets with open gangways between cars, similar to the design of articulated buses. This will both maximize carrying capacity, and allow passenger to move to less-crowded areas of the train, balancing loading and unloading times at all doors.

The articulated trainsets aren’t arriving with any of the current rolling stock orders. The R179s and R211s won’t feature open gangways. So it’ll likely be until the mid-2020s that we see any such cars hit the rails in New York. By then, the R62 cars currently in use on the 1 and 3 lines will be nearing retirement age, and the 1 in particular would be a prime line for articulated cars as, outside of the old South Ferry station, the curves are essentially non-existent.

So why then don’t we have these open gangways already? Back in 2009, Yonah Freemark tackled the question and received the following response from an MTA spokesman: “MTA New York City Transit had considered an articulated train which was proposed by Kawasaki under the R110A contract. The proposal was, however, rejected by us due to the impact it would have had on the project’s budget and schedule…We may take another look at articulated trains in the future if and when we have a budget for Research and Design for an entirely new subway car.”

Basically, as with anything new, it cost too much. But now the MTA has a twenty-year plan and a vision for future train sets. If the tunnels can handle them, the next-gen rolling stock should have open gangways. It’s a minor improvement that can make a dent in reducing overcrowding and improving ease of movement in crowded subway cars.



Categories : Rolling Stock

99 Responses to “A look at the 20 Year Needs: Articulated trains”

  1. Alon Levy says:

    It always annoys me when they say “cost too much.” How much extra will it cost?

    • al says:

      It annoys me when people conflate articulated with enclosed open connecting gangways.

      Part of the resistance to is resistance to extra cost that can bring down ownership costs via increased capacity and/or decreased ownership cost. Upsetting the existing order can bring out naysayers and enemies. The current MTA bureaucracy doesn’t encourage innovation and deep analysis of the way they do things.

      The MTA should look at the gains from plug doors vs existing pocket doors, and what the PANYNJ did with the PA1 train set order back in the mid 60’s. Plug doors allow for thinner side walls and improve passenger compartment’s clear width. The PA1 design’s bulge maximized train car volume. If the MTA wants more capacity without adding rolling stock count, expanding yards, lengthening yard tracks, and extending platforms, this is the route.

      The Crash Energy Management Systems developed for heavy rail and HSR should be adapted for subway cars to reduce the weight of future trains. The R160’s 86,000 lbs empty weight reflects an older design philosophy – heavier better – is way heavy, and might not handle anything beyond a low speed crash without telescoping. Bringing a 60 ft B Division back down below 70,000 (pre-rebuild R32) would make for less wear on tracks and elevated structures. Lower weight also improves energy consumption, acceleration and braking distance (esp emergency braking distance). All of which would improve direct and indirect ownership costs.

      Gearless traction systems, axles with differentials/independent wheels, and steering axles that follow curves and not grind up wheel flanges and rails would also greatly reduce the noise profile of subway trains moving through switches and around curves. They would also reduce track and wheel maintenance/replacement costs.

      • Spendmore Wastemore says:

        “The Crash Energy Management Systems developed for heavy rail and HSR should be adapted for subway cars to reduce the weight of future trains.”

        And make the occasional crash less severe.
        Something as simple as
        1) Add a crushable, quick-change extension at the train ends. There hould be room for 3 ft with no real issues parking or running. The trains seem to have the same front and back for long periods, and the extensions could be changed in minutes in a shop.
        2) Design the couplers to telescope under crash force and the small area between cars to catch and crush (so one car can’t climb over/under the next).

        You can absorb a lot of energy in 18 or 36 inches. Multiply that by several cars and a major wreck can become a modest one.

        Now quit slowing the trains to a crawl half a mile before every switch or historic accident site.

        They won’t, it makes too much sense.

      • Alon Levy says:

        Crash energy management is billed as an alternative to a buff strength requirement that doesn’t even affect the subway.

        On subways, the correct approach to crashes and derailments is not to have them, even more so than on mainline rail.

  2. TransitTransient says:

    It sounds good in theory, but (semi-seriously) what happens when a car inevitably has a terrible smell? Now you lose a double length car instead of confining it to just one.

    • Danny says:

      You just follow the best practices of the many other cities that already use these kinds of trains. It’s not like you’re reinventing the wheel here. I can see this being a benefit if the A/C goes out in one car – at least you’ll get some cool air flowing in from the cars next to it.

      • Matt says:

        You may be underestimating the traveling ability of New York City bum stench.

        • Henry says:

          To be fairly honest, separate cars doesn’t always solve the problem, either. It already has the ability to penetrate the doors at times (particularly if the bum is at the end of a car).

        • Spendmore Wastemore says:

          That’s a political issue. NYC has collectively decided that people have the freedom to defecate on themselves +/or never wash and to bless others with their presence.

          In my experience, it tends to be only politically minded people with private cars +/or money who hold this view.

  3. marv says:

    Let’s clarify what is gained and lost with these cars to determine if the extra cost is worth it.

    gained:

    *more passenger space/passengers per train (due to removing both the gap between the cars and the thickness of the skin of the cars
    *passenger distribution as people with move more freely which then allows more even boardings and shorter dwell times
    *safety as passengers are not trapped in a car

    lost:
    *added cost
    *containment of fire, smells, hoodlums, adverse heating/cooling adversities due to units breaking down
    *operational flexibility as breaking down train sets and swapping in an out individual cars is more difficult.

    Is it worth it? – I am not sure at this time.

    • Nyland8 says:

      gained:

      *while riding the L Train stretch between Bedford and 1st Ave, we get to watch acrobatic pole dancers go tumbling from the front of the train all the way to the rear … and back … before they pass the hat.

      lost:

      *our eardrums in the process.

    • Alon Levy says:

      In most modern rail systems nowadays trains are semi-permanently coupled into sets even when they don’t have gangways. It makes maintenance easier since all cars in a set have the same history.

      Gangways are actually better at containing hoodlums since passengers can escape. SNCF in fact specifically started ordering trains with gangways for safety reasons.

      • lawhawk says:

        Gangways also reduce ability for people to fall between cars as they can now – out of negligence, stupidity, or accidents. It also limits (or prevents) idiots from getting out on top of the subway cars as has happened in the past.

        Closed gangways would be a significant safety improvement and expand the car capacity – an issue with limited funds to build new capacity and the time it takes to build out the new signal systems.

        This new effort should come with an effort to standardize door placement across the rolling stock.

        All in all, a good thing that the MTA should seriously consider.

        • Bgriff says:

          Unfortunately (with respect to any possible platform screen doors effort or the like) the MTA seems committed to keeping a mix of door placements — the 20-year plan also calls for new B-division cars in both 75-foot and 60-foot variants.

          • Andrew says:

            It does? Where did you see that?

            All I see is this sentence: “For the purposes of this plan, it is assumed that the B Division will continue to operate a mixed fleet of 60 foot and 75 foot cars; and the cars to be purchased in the 2015-2034 period will be 75 foot cars, based on the length of the existing R-46 and R-68/R-68A fleets.” It’s a working assumption to preserve both options – in the absence of a decision, this planning document has to make an assumption one way or the other in order to come up with numbers.

            • Henry says:

              Isn’t the new B Division car order for 75 footers?

              • al says:

                Has anyone seen the (75′) Toronto Rocket in Toronto in action over switches?

              • Andrew says:

                Source?

                The sentence I quoted above clearly implies that the issue is still under evaluation, or at least that it was at the time that the plan was written.

                  • Andrew says:

                    “NYC Transit is currently evaluating train and car configuration options for the R211 fleet.”

                    There is virtually no physical way that open gangways could be compatible with a 75 foot layout (within the confines of the NYC subway), yet it’s explicitly listed as under consideration.

                    The opening sentence isn’t worded clearly, but it’s simply giving the size of the fleet if the ultimate decision is to order 75 foot cars.

                    • Joey says:

                      If open gangways require slightly shorter car bodies (and I’m highly skeptical that they do), then shorten the bodies by a couple of feet. What matters is length over coupler faces, and door spacing.

                    • Andrew says:

                      Here’s what happens when 75 foot cars go around sharp curves on the subway:
                      http://www.youtube.com/watch?v=bZXP4vTRPDE

                      The end excess is simply too great (and the trucks can’t be slid out to reduce the end excess, because the center excess would then be too great for the clearances around the subway system).

                      None of this applies to 60 foot cars. Any discussion of possible open gangways on the B Division refers to 60 foot cars.

                      And I am referring throughout to length over coupler faces.

                    • Joey says:

                      The angle between the cars is large, as is the difference in space between the inner edges and outer edges of the cars, but to my knowledge that’s not anything open-gangways can’t handle. And they don’t increase the envelope of the cars by any appreciable amount. If there aren’t clearance issues with separate cars, there won’t be clearance issues with open-gangway cars.

                    • Andrew says:

                      Sorry, I don’t understand what you’re saying. How would open gangways deal with 0:46 and 2:49? What happens to the people standing in the gangway when the train rounds those curves?

                    • Henry says:

                      What exactly would be the difference between a articulated bus making this curve and an articulated train? If an articulated bus can round a corner without injuring passengers in the accordion section, what would make it any different from an articulated train?

                    • Andrew says:

                      Articulated buses are different from articulated trains, and articulated trains are different from non-articulated trains with open gangways.

                      The rear section of an articulated bus has only one axle, so there’s no end excess issue.

                      An articulated train has the trucks underneath the articulation joints, so, again, there’s no end excess issue. There is, however, a potential center excess issue if the cars are not significantly shorter than the ones they are replacing.

                      A non-articulated train with open gangways has the exact same end excess issue as a non-articulated train without open gangways, plus, obviously, the need to provide safe passage between cars on the sharpest curve or crossover in the system. It’s a real engineering challenge. I don’t know if it’s feasible, and if it’s feasible I don’t know what it would cost.

      • Owain says:

        An additional safety benefit is that articulated trains would also allow police officers to observe far more of a train from one position than they can at present. They would also make for a faster evacuation through the length of a train in the case of fire, too.

    • BBnet3000 says:

      A/C units breaking is probably better on articulated trains, as the a/c is shared between all the units.

    • Bolwerk says:

      I think most of those gains and losses are fairly minor.

      But how many more people can fit on an articulated train? Assuming 5 articulated pairs, which probably wouldn’t even be that maintenance-intensive, it would seem to me that you get a few hundred square of space. It’s something, but not even a carload per train.

  4. Larry Littlefield says:

    If they don’t standardize the door placement, how can they have platform doors?

    We just had a discussion of platform doors on this site, and now they are discussing moving the doors again for a new car class.

    • Alon Levy says:

      Why do articulated trains have to have different door placement from non-articulated ones?

      • Larry Littlefield says:

        The Triplexes certainly did. And, by the way, the Triplexes didn’t last as many years as the Standards. Which is another reason why NYC Transit should standardize.

        • Alon Levy says:

          I’m thinking less about the Triplexes and more about modern subway cars in Singapore, Shanghai, Vancouver, Paris, and other cities. The length per car in those cities is the same as on the non-articulated trains the newer trains replaced, and the door placement looks similar to that on non-articulated trains.

          • Andrew says:

            Do Singapore, Shanghai, Vancouver, and Paris have articulated subway cars? They have cars with open gangways, but I don’t believe they’re articulated.

            Larry was discussing truly articulated cars, like the Triplexes. In order for a pair of cars to share a truck, each car often has to be shorter, and that affects door spacing.

            • Alon Levy says:

              No, although there exist trains with articulated bogies with car length up to 20 meters (on the TGV). But this discussion was never about articulated bogies, and always about open gangways, or walk-through trains, or whatever you want to call them.

              • Andrew says:

                In his references to door spacing and to Triplexes, Larry Littlefield was clearly referring to actual articulation. You didn’t understand him because you assumed he was talking about open gangways. He was not.

                Yes, there are truly articulated trains, but they’re quite uncommon in the context of subway/metro/urban heavy rail systems. Nobody says that articulation can’t coexist with long cars, but articulation with long cars requires a wide clearance envelope, which most subway systems cannot provide.

    • Epson45 says:

      Unless it was mention on this site. MTA will still have a mixed fleet of 60 ft and 75 ft cars… R-211 cars will be 75 ft.

      So much standardized fleet!

      • FivePoint says:

        “R-211 cars will be 75 ft”

        Source please?

        • Bgriff says:

          20-year Needs Assessment mentions it.

          • Larry Littlefield says:

            Again, makes no sense. This isn’t about wanting or not wanting platform doors. It’s whether they should be precluded for the 50-year life of the new cars.

            I often wondered who was behind the shift in door position. The union, because they felt platform doors might limit the need for conductors, or management. It appears to be management.

          • Andrew says:

            Where’s that?

      • Bolwerk says:

        The MTA has such a big fleet that it can have a few sub-fleets with different standards based on its needs and not raise costs significantly. And all cars can (and, on new models, presumably do) have standardized components, whether division A or B.

        The hard part, as Larry mentions, is sensibly standardizing the doors – or coming up with a platform screen solution that accommodates significant variance in door spacing.

  5. John-2 says:

    Since the BMT did more than just experiment with multi-section cars back in the 1920s and 30s, hearing the MTA’s explanations now on why it can’t be/hasn’t been done sounds like people who know better — as far as what they could put on the system — but simply don’t want to engage the issue until they can do it on their own terms.

    (It would actually be interesting if they could ever get the Transit Museum’s D Type cars running again, to use their on the Holiday Special and gauge passenger reaction to the cars on their multi-section feature.)

    • Michael says:

      Exactly, I’m surprised to here this is viewed as something new when the BMT used to run 3 car articulated sets.

      Articulated trains have many advantages beyond the open gangways.
      They can run faster on tight curves
      have lower maintenance costs due to half as many bogies.
      Are safer, and less likely to derail of jack-knife.

      This is a long overdue change to make a more efficient system. The next ind trains should be articulated to help with the systems tight curves.

    • BruceNY says:

      I’ve actually ridden on the BMT D-Type “Triplex” on Transit Museum fan trips in the past. I think that they don’t use this during the Holiday Specials because they have enough IND R-types to form a complete train and can use those for normal service, while one Triplex unit is too short (137 feet), and they’re not compatible with R1-R10’s.
      I have yet to ride on a BMT “Standard”. I recall seeing one being painstakingly restored in the Coney Island shop on another Transit Museum tour, but that was maybe 15 years ago. Does anyone know the fate of that car?

  6. Henry says:

    How well would an articulated car be able to handle curves, such as switches used for GOs and things of that nature?

    • Handsome Johnny says:

      The 122 3-section “D Type” cars operated from the mid-1920’s to the mid-1960’s and were able to handle curves. So were the thirty or so 5-section “Multisection” BMT articulateds. What is the logic underlying your view that articulated vehicles cannot handle curves as well as those connected by standard couplers?

  7. Scott E says:

    Was this reference specifically in the context of subways? I would expect to see articulated trains on Metro-North and LIRR before the subway. Less curves, less crowds, and so forth. It just seems like a more logical place to start. Then again, most of the commuter trains are relatively new.

    • BBnet3000 says:

      Crowding is a reason for the added capacity of articulated trains.

    • Henry says:

      You could maximize capacity on the LIRR and MNRR by removing that third seat before you went on to articulated sections.

      • SEAN says:

        NJT’s bilevel cars removed the third seat. Speaking of witch, the MTA needs to invest more in bilevel cars them selves especially after the power issues last week. They can be designed to fit both the East River Tunnel & under Park Avenue.

  8. Adam says:

    Articulated railcars can always be designed to handle New York’s curves. In fact, if they’re designed properly they could probably do a better job than the existing cars. And it’s not like this is brand new technology. I’m sure they could just modify some of the rolling stock they use in places like Barcelona to fit our dimensions and replace pantagraphs with third rail paddles (then again I think flood-prone lines should use pantagraphs instead of third rails anyway).

    • BruceNY says:

      This is not a new concept for New York to design into by any means. In addition to the BMT Triplex, which were used in large numbers, they also had other articulated train models: “The Green Hornet”, the stainless “Zephyr”, the “Multi-Section”, and the elegant “Bluebird”. Sadly, other than the Triplex, all were eventually scrapped.

  9. John T says:

    The newest London Tube trains are articulated, they run on the Hammersmith & City line, which is over 100yrs old.

    NYCT should have taken the opportunity with the R142 on because they are already fixed sets of 4-, 5- and now 6=car (R188s) trains. Maintenance is much improved since the 1970s when too many BO trains would seriously reduce service. The overreaction then where single car R62s & R68s, which later were rebuilt into sets anyway.

    I don’t understand the big deal here. Must we wait for the PATH to order these first?

    • Adam says:

      PATH is an FRA railroad; I don’t think they can have articulated cars until they sever the one connection to the NEC next to the Harrison shops.

  10. Charles Moerdler brought up the idea of articulated trains for the commuter rail systems at the last LIRR committee meeting. While they probably wouldn’t be able to work as he intended them to for the LIRR, I’d say it’s a good possibility we could see some sort of articulated train coming to the subway in future car orders.

  11. Demetria says:

    In a system in which any kind of meaningful expansion has been ruled out , the only way to expand is by adding capacity. This was done in the 1950s with the platform lengthening now, and is being attempted now with CBTC. One would imagine the logical next step (and possibly the cheapest considering rolling stock has to be replaced anyway) would be articulated trains. And any talk of “New York’s curves” precluding such trains is nonsense. Yes, New York has curves. So do many systems. Technology advances have made this argument mute.

  12. tacony palmyra says:

    You don’t need to go to Europe to see articulated trains in action. Toronto has ’em: http://en.wikipedia.org/wiki/Toronto_Rocket

    They’re very smooth, quiet, comfortable, and handle crowds well.

    • Even the Hudson-Bergen Light Rail just across the river has articulated trains to some extent. It’s not a completely unknown concept, it just hasn’t been attempted in New York yet.

      • SEAN says:

        I was thinking about HBLR while reading the other comments, but those cars have only two articulated sections as compared to what the TTC has in it’s fleet.

  13. RB says:

    Echoing “tacony palmyra”. You don’t need to go to Paris. This technology is ~350 miles from here.

    Toronto has had these trains on the Yonge/University/Spadina line for several years now. They are very nice and allow people to board wherever they like and exit at a different spot. Bunching and crowding within the trains is minimized.

    • SEAN says:

      Meanwhile the TTC is expanding two of it’s subway lines northward. One is going to Vaughn, & the other is going to York University in Brampton.

  14. Rob says:

    Although the novelty and curve excuses have been rightly discredited, what abt the question: HOW MUCH capacity could they add? Enough to be worth considering them, aside from maintenance savings, etc.?

    • Joey says:

      Even if the capacity gain is only marginal, the improvements in safety and passenger convenience probably justify them on their own. There’s a reason they have near universal adoption on other continents.

    • Bogstandard says:

      10% or thereabouts

      • Andrew says:

        That doesn’t seem credible. Open gangways add space for a few more people to stand at each car end.

        A 10 car train of 60 foot cars has a guideline capacity of 1450. Are you seriously suggesting that adding 8 gangways would provide space for 145 additional people on the train? That’s 18 people per gangway – per NYCT’s guideline of 3 sq feet per standee, you’re saying that the space between cars that’s currently unavailable for standees but would become available is 54 sq feet per gangway!

        At a very generous estimate, I’d say that each gangway couldn’t be possibly be larger than 30 sq feet (5 ft long x 6 ft wide), or 10 people per gangway -> 80 people per train -> a 5.5% increase in capacity. And even that, I think, is a stretch.

  15. nycpat says:

    Lots of New Yorkers want to know: Where do you go to the bathroom on an articulated train?

  16. Andrew says:

    Watch your terminology. Articulation and open gangways are entirely different things, and a train can have either one or the other or neither or both. Some of the comments above refer to articulation, and others refer to open gangways.

    Articulation refers to shared trucks between cars. Most articulated cars have open gangways, but the converse is not true, certainly not on heavy rail transit systems – very few heavy rail transit systems have articulation, while open gangways are becoming fairly common. (Articulation is more common on light rail systems.)

    Articulated trains are potentially cheaper than non-articulated trains, because there are fewer trucks – but if the cars have to be shorter in order to compensate, that benefit quickly vanishes. I doubt we’ll see articulated trains here.

    Open gangways don’t necessarily require shorter cars, although I doubt 75 foot cars could have open gangways in New York. Whether 60 foot cars would be compatible with open gangways depends on the radius of the sharpest curve in the system (or in the portion of the system that these cars would potentially run on). I certainly haven’t done the engineering study, but the answer depends on the specific details of this specific subway system – simply declaring that other systems have open gangways isn’t sufficient.

    And while, if open gangways are feasible, there would be definite benefits, there would also be downsides, most notably cost.

    • Henry says:

      If the MTA were to go with open gangways, wouldn’t it be possible for the MTA to reduce car size and increase gangway size while maintaining a 75 ft distance between the middle of the gangways?

      • Joey says:

        Car length is more properly measured over coupler faces rather than the length of the car body anyway. That’s the measurement you want to keep constant.

        • SEAN says:

          Thanks for the clarafication. I was watching a few YouTube videos on the Toronto Rocket & you can clearly see the various car sections as if they are seperate units, but of course they are not. I will say this, they are quite sleak looking with the stainless steel shell & sloaping front ends at the cab posissions.

    • Alon Levy says:

      The sharpest curves in New York are on the IRT, where car length is the same as on Paris Metro Line 1, which has open gangways.

      When someone says “New York is special,” the first assumption must be that they suffer from NIH syndrome, not that they’ve actually checked and found an insurmountable difference between New York and other cities.

      • Andrew says:

        This is your engineering study?

        • Alon Levy says:

          “It’s done already in a system with the same track geometry as New York”? Yes. It’s better than any “but it’s different here” argument you’ve made.

          • Andrew says:

            Have you looked at every switch on the system, every yard lead and yard track, to determine the actual maximum curvature? Have you compared the truck spacing in Paris vs. New York? (If the trucks are closer to the center of the car in New York – and I have no idea if they are – then the end excess is greater.)

            I am not discarding the notion of open gangways in New York. I am saying that a detailed engineering study, revolving around the specific details of New York’s system (which are different from the details in Paris), needs to be done before anybody can make a definitive statement regarding feasibility, cost, etc. I would like to see open gangways if they are practical, but I don’t know if they are.

            I don’t even understand why you’re focusing on the IRT – the oldest cars on the IRT aren’t up for retirement for another 11 years. The next car order is the R211 order, to replace the R46’s. If the R211 order is for 75 foot cars, then open gangways are almost certainly off the table. If it is for 60 foot cars, open gangways might make sense. But even ignoring the open gangways themselves, 940 60 foot cars cost a lot more than 752 75 foot cars.

            • Alon Levy says:

              Because the IRT has the worst curvature – and incidentally it’s not even on revenue track but at City Hall, so unless people in the forums are just mentioning City Hall because it used to be revenue track, it also applies to yard track.

              The curvature on the BMT should be as compatible with 60′ open gangways as the curvature on the IRT with 51′ open gangways, based on the square-of-car-length law.

              In photos, the R142 bogie placement seems the same as the one on the MP 89.

              http://en.wikipedia.org/wiki/F.....arison.JPG
              http://en.wikipedia.org/wiki/F.....-MP89-.jpg

              940 60-footers with open gangways have more capacity than 752 75-footers with no covered inter-car connections. What’s the cost of providing the same extra capacity by upgrading signaling?

              • Andrew says:

                Because the IRT has the worst curvature – and incidentally it’s not even on revenue track but at City Hall, so unless people in the forums are just mentioning City Hall because it used to be revenue track, it also applies to yard track.

                First of all, a technicality: City Hall is revenue track. But how about crossovers from one track to another? New York has many more than Paris, and some are quite tight.

                Whether or not the IRT has the worst curvature, it also has the shortest cars. The feasibility of open gangways on 51 foot cars has no bearing on 60 foot cars!

                The curvature on the BMT should be as compatible with 60? open gangways as the curvature on the IRT with 51? open gangways, based on the square-of-car-length law.

                I’m sorry? The square-of-car-length law? I’m not familiar with that law.

                I’d hope that the folks working on the potential car design are doing so through actual engineering assessments based on actual track layouts.

                In photos, the R142 bogie placement seems the same as the one on the MP 89. http://en.wikipedia.org/wiki/F…..arison.JPG http://en.wikipedia.org/wiki/F…..-MP89-.jpg

                I’d hope that the folks working on the potential car design are not basing their work on gut feelings derived from small internet photos.

                940 60-footers with open gangways have more capacity than 752 75-footers with no covered inter-car connections. What’s the cost of providing the same extra capacity by upgrading signaling?

                Nice try, but NYCT replaces signal systems when the old signal system is life-expired, and CBTC is the standard for all future NYCT signal systems (after the Dyre Avenue line).

                NYCT isn’t going to spend an undetermined sum of extra money to adopt a car design that yields undetermined benefits and might or might not be feasible given the actual physical infrastructure that they’ll be placed into. The evaluation process will first determine a specific design that is feasible (assuming one exists, which I think is likely) and will then identify the benefits and the costs (monetary and otherwise) of that specific design. If the benefits significantly outweigh the costs, or if the costs significantly outweigh the benefits, then the decision is obvious. More likely, the outcome will be fuzzy, and somebody will have to make an informed decision based on the facts.

                • Alon Levy says:

                  “Undetermined benefits” like more capacity, which New York doesn’t need. Okay.

                  Re the square-of-car-length law, it’s just geometry. For a fixed car layout, scaling the car’s length by a factor of x will also scale the associated gaps coming from the difference between an arc and a chord (inter-car gaps as well as train-platform gaps) by a factor of x^2.

                  Unlike you, I don’t actually trust the MTA to make an informed decision based on facts. The MTA is extremely resistant to adopting successful industry practices from outside the US, and when it’s trying to change its practice, it ends up reinventing the wheel – see, for example, Walder’s ideas of commuter rail ticket taking. Other US agencies have a history of being uninformed or dogmatic about practices abroad when pressed. Bay Area transit activist Richard Mlynarik reports that when he mentioned Japanese train turnaround times to Transbay Terminal planners, one of them responded, “Asians don’t value life the way we do.” And when Stephen Smith asked the FRA about the buff strength limit, the FRA lied that US trucks are heavier than European trucks. I don’t think the MTA is so much more forward-thinking that it wouldn’t say something similar if it actually started answering Stephen’s questions.

                  • Andrew says:

                    “Undetermined benefits” like more capacity, which New York doesn’t need. Okay.

                    Care to quantify? Cost-benefit analyses are impossible without quantification of both costs and benefits. The MTA doesn’t have an unlimited capital budget.

                    Re the square-of-car-length law, it’s just geometry. For a fixed car layout, scaling the car’s length by a factor of x will also scale the associated gaps coming from the difference between an arc and a chord (inter-car gaps as well as train-platform gaps) by a factor of x^2.

                    Very good. Now tell me how open gangways will perform on a 60 foot B Division car with B Division truck spacing designed to accommodate the sharpest curves on the B Division.

                    Unlike you, I don’t actually trust the MTA to make an informed decision based on facts. The MTA is extremely resistant to adopting successful industry practices from outside the US, and when it’s trying to change its practice, it ends up reinventing the wheel – see, for example, Walder’s ideas of commuter rail ticket taking. Other US agencies have a history of being uninformed or dogmatic about practices abroad when pressed. Bay Area transit activist Richard Mlynarik reports that when he mentioned Japanese train turnaround times to Transbay Terminal planners, one of them responded, “Asians don’t value life the way we do.” And when Stephen Smith asked the FRA about the buff strength limit, the FRA lied that US trucks are heavier than European trucks. I don’t think the MTA is so much more forward-thinking that it wouldn’t say something similar if it actually started answering Stephen’s questions.

                    Nice rant (although I got bored midway through and stopped reading), and you have every right to disagree with whatever MTA decisions you disagree with. But we’re not at that stage yet – we don’t even have the basic facts on the ground on which a decision can be based. How about we let the car designers and engineers come up with feasible designs and quantify the costs and the benefits of each of those designs? Once that’s done, the MTA decision-makers will weigh the options and make a decision, and I’m sure you’ll disagree with it. But at least you’ll be able to disagree based on facts.

  17. Ed C says:

    You might want to check this out:

    • This doesn’t prove anything really.

      • Andrew says:

        No, but it does demonstrate a potential challenge.

        And an open gangway that narrow wouldn’t be terribly helpful – it’s certainly much narrower than on the MP89.

        • Alon Levy says:

          Why not? Open gangways narrower than full width are still useful for some space and for getting easily between cars.

          See for an easily accessible example from Seoul here. Except that the car in the video is unrealistically empty.

          • Andrew says:

            It virtually eliminates any possible capacity benefit, and once somebody’s standing in the gangway, he or she blocks passage.

            A gangway like that is better than what we have now, but only marginally so.

          • Nyland8 says:

            Oppan Gangway Style !!

            Seriously though, it seems quite obvious that there are benefits to open gangways – and perhaps articulated train sets too.

            And anyone who has ridden the most recent vintage articulated busses knows that not only standing and moving room, but even some seating can be gained by proper design of open gangways. By comparison, it seems like NOT having them is a waste of space.

            • Andrew says:

              Certainly there are benefits. Nobody’s denying it. The questions are (a) what sort of open gangway is feasible in New York, given the specific physical characteristics of New York’s infrastructure; (b) how can the benefits be quantified; and (c) how can the costs be quantified. If the benefits are great and the costs small, then, obviously, do it. But if the benefits are small and the costs great, then it may not be a worthwhile investment.

              Articulated buses are 50% longer than non-articulated buses. Trains with open gangways are exactly the same length as trains without open gangways; the capacity gain is only in the small space between cars. You’re overstating your case.

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