38 Replies to “Sunday Open Thread: New Tube for London”

      1. Because maybe sometimes something is so obviously the right thing to do that even the Seattle Times can’t find a reason to oppose it?

        A lot of things will change for the better if Prop 1 passes. Kudos to Mayor Murray for putting this together – this is the way progress is made on transportation.

      2. I suppose you’re right. I was thinking and hoping maybe they woke up or something.

        I temain more optimistic about them doing so than our remnants of a newspaper.

      3. Well, I certainly wouldn’t rule out some nefarious anti transit purpose on the part of the Times, but it it isn’t clear how this is it

    1. Wow! Have the ever endorsed a transit tax that didn’t include a substantial roads component before?

  1. One of the problems on the deep level tubes is that there isn’t much ventilation, so the tunnels get very hot. More efficient motors and better brakes mean less heat into the tunnel air, but traditional air conditioning will only make matters worse as that would dump hot air into the tunnel.

    So, one of the solutions being developed (I’m not sure if for this particular stock) they have an interesting solution that would build up a quantity of ice when the train is on the surface, and use that as the source of cooling when the train is underground.

  2. so are there no system maps at the pronto bike share stations, like every other bike share system ive seen? if so, that seems like a flaw. it helps so much to find the station and route for your destination

    1. Instead of the whole system, wouldn’t it make more sense to have a station area map with just nearby stations indicated? In other words, places you can go to return a bike if you find a full rack, or to pick up a bike if you find an empty rack. This also helps with pedestrian wayfinding.

      A full system map would such a large scale it wouldn’t be particularly usable.

    2. I see some maps on the helmet return bins.

      The full system map, as of now, isn’t very large, and is useful for knowing whether you can dock your bike near your destination, or have to keep it out (and risk going over time).

    3. The website says it gives a real-time indication of where the nearest stations are and how many bikes they have and whether they have a slot open to return a bike.

    4. Since bike share is one of the lowest cost forms of transportation other than walking (if you use it regularly and get an annual membership) it is kind of a shame that to get the best benefits of the system you really need to be able to afford a smart phone. Pronto stations are already showing up on Transit App, Spotcycle and supposedly Pronto’s own app will be available tomorrow (after the 1 PM launch time?).

      1. Yes, that is regrettable. I can’t think of a good SMS interface for bikeshare capacity information. (you really need user location and a way to show everything nearby)

  3. I’m currently in the process of designing a Seattle Metro system, a scenario where Puget Sound chose a more conventional Heavy Rail subway from the start. By 2014, there will be 14 lines in total. I’m also planning on going into depth on not just how the lines were decided, but how the Metro affected the development of Puget Sound.

    1. Very interesting; I’d love to see your result. Are you starting by pretending Forward Thrust passed, the trolleys were never torn down, or something else entirely?

      1. Something else. The Point of Divergence here is sometime in the 1920’s (essentially Robert Moses never gains the influence that he did, and things snowball from there), but the actual construction of the Metro doesn’t start until the mid 1940’s (about a decade or so early, but the geography is especially favorable in Seattle). The first two lines (Known as The Flaunteroy Line and Overlake Line respectively), do look somewhat like what was planned in Forward Thrust, albeit on different routes through the Downtown. (Something I should emphasize here, when I say Line, I mean Line. Each line has it’s own set of tracks in each direction, and doesn’t share tracks with another line during regular service)

      1. Oh, I’ve already come up with a lot. I’ve already figured out how the system in look circa 2014 (It’s going about 320 miles long), it’s more a matter of hashing out stations and putting it down on paper.

        As for Kenmore, I can say that it will have Metro service on Line 4, the Duvall Line.

      2. No, more it was named largely on account of aspirations, and partly because they wanted to save the other main suggestion “University Line” for a later line.

  4. I hope they squeezed everything out of the old tube before they started using the new one.

  5. So are the sections of the train removable? Or does the the whole train have to go out of service if one part of the car is inoperable?

  6. You all know how much I hate to throw wrenches in the conventional wisdom, but…

    Recent experience in China suggested to me that platform doors really do have a significant deleterious effect on dwell time, thus throughput, thus total line capacity.

    I came to estimate that an additional 25-30% dwell time at every single stop on a Chinese subway line is directly attributable to the longer warning phase, slower door movements, and additional seconds of synced lock-securement made necessary by the platform door approach, as compared to any equally high-volume, level-boarding legacy heavy-rail line in New York, Berlin, or London. This was true whether the platform doors were ceiling height or merely waist-height.

    On trips that covered great distances and passed through a lot of intermediate stops, you really start to notice how much this slows down the train. Even with Beijing or Shanghai’s exceedingly short waits for the next train once the first has left the station, I couldn’t help but think that the very long dwell times were costing the system multiple trains per hour, and were in part responsible for the need to continuously build parallel “reliever” lines as close as a few blocks away.

    Since London does not have the plentiful and cheap Chinese labor that would be required to build a bunch of new lines from scratch, I really hope someone is accurately assessing the platform-door slowdown effect and working it into TfL’s capacity and efficiency models. If not, the city could be in for a rude awakening when this particular signifies of modernity has the opposite of its intended effect on their easily-strained transport network.

    1. Umm, I think that some of that slowdown might be due to the fact that the Drivers are still responsible for opening and closing doors?

      1. No, the physical/mechanical process of opening and (especially) closing the double doors was truly and palpably longer than in comparable metropolitan systems. By many, many seconds, multiplied by a dozen stops or more.

        The dwell time was similar to Link (which is, of course, invariably 20 seconds longer than it needs to be). When you’re dealing with genuinely high volumes and a genuine need to scale, such seconds add up to a huge freaking problem.

    2. Compare a car stopping at a stop light vs a car stopping at one of these door holes. The first car just stops and opens its doors and people get out. The second car has to slow down to 5 mph and creep up to the door to get it exactly aligned, and often it overshoots and has to back up a bit, and forward, and then it can open the doors. I saw it in St Petersburg and it’s intrinsically slower. I don’t know why London is going with it because it was widely regarded as a failure in St Petersburg. Maybe a driverless train can slow down at just the exact time to stop right in front of the door, but with a margin of error of less than an inch, that would have to be proven.

    3. I think it really depends on the level of automation. If stopping the train is fully automated having it line up accurately with the platform doors is trivial.

      d.p., do you have experience with any other transit systems with platform doors? Did you notice the same increase in dwell times?

      1. I’ve never been on the Jubilee Line or the Paris Métro 14, but the Chinese dwell delay was equally noticeable in three different cities.

        I would also point out that “full automation” has long been standard on platform-doored airport systems, from the very old (SeaTac) to the very new (SFO, JFK). The dwell-time redundancy and intentionally slow-moving doors on these systems are generally as bad or worse than the semi-manual slowness seen in China.

        I just don’t think it’s about having drivers lining up the cars or not. It’s the mechanistic overdesign that makes it slow.

        This is a common problem with engineering that is defined uncritically as “progress”, but is often rendered by those who need not use system whose efficiency their “innovations” reduce.

      2. I’m just curious because I really haven’t heard anything about increased dwell times with platform doors. Given how widespread they are, including places with a culture of not tolerating transit inefficiencies for long, I’m not sure how much of a real issue it is when the system is designed properly.

        Then again maybe those places simply see the benefits of platform doors as outweighing their downsides.

        Speaking of APM systems while the Seatac system has some of the slowest trains of any airport I’ve been in the doors are among the quickest to open after a stop. (The dwell times are still too damn long though) Atlanta’s system is one of the slowest to open the doors after a stop (15 seconds or so) even though they use more or less the same system as Seatac. The train speed issue isn’t so much a problem there due to the close stop spacing.

      3. I experienced platform doors on the Singapore system. I don’t know if the trains were automated or not. I just remember the platform area was enclosed so it could be climate controlled.

      4. It’s a good question, Chris. While I tend to like visiting cities that are well transit-enabled, I don’t tend to be a “transit tourist” in the way many on this blog are. I don’t ride to inspect differences; I ride to get around. That’s why I haven’t seen the Jubilee Line or Paris Line 14 — I’ve been in both cities since their platform doors existed, but I guess I just happened never to need those lines.

        My point is that I was in no way expecting the dwell-drag from the various platform doors in China to be as noticeable as it was. But even after a week and a half in three very different parts of the country, it remained hard to ignore.

        It isn’t just the speed of each door (which is slightly slower than elsewhere). It’s the longer warning phase. It’s that the inner door tends to follow about a second behind the outer door. Most importantly, it’s the dwell between when the doors click-lock and when the train is released to move forward, which cost a minimum of a few seconds each time. And it’s the mirror of all of these processes upon each arrival at the next stop.

        All of these seconds transpire without anyone being able to board or alight, which really does make the process different from old-fashioned subways anywhere — in Boston, New York, or Paris, the train doesn’t sit at the platform for a single instant that people are not entering or exiting somewhere.

        Per your own point of reference: SeaTac’s doors may move less lethargically than many double-doored airport shuttles, but they still move far slower than normal subways (even Link, whose doors are hardly guillotines). But the next time you’re headed to the North Satellite, don’t notice the doors themselves. Notice the time that elapses as they latch, then the vehicle waits, then waits some more, then finally sends you on your way.

        Then imagine doing that for 20 consecutive stations.

        This is a real problem.

      5. Just to throw a wrench into this discussion: The Jubilee Line doesn’t have platform doors at all its stations. I took it just about every day when I was in London earlier this year, and none of the stations north of Westminster have platform doors. (At least as far as Finchley Road – I didn’t take it north of there, but that’s suburban enough that I don’t expect anything farther out had them either.) I don’t remember any delay lining the train up at Westminster, but I might not have noticed a couple seconds for that one very busy stop.

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