25 April 2015

The Blue Doors Will Open

Blue doors open at old 8" platforms (shown here)
Yellow doors open at HSR height
There are noises that Caltrain's new EMU fleet might sport a double set of doors, to enable boarding at two different platform heights.  While this isn't necessarily ideal, it is a reasonable solution given the constraints of the problem.  And yet, the prospect of trains with double the usual number of doors elicits gasps of horror from some transit advocates and industry insiders.  Let's go through some frequently asked questions to explore the roots of this choice, and feel free to ask more in the comment section.

Q. Do you intend for every Caltrain platform to be rebuilt?

A. Yes!  Today, the number of Caltrain platforms that support level boarding is zero.  In order to achieve the short and predictable station dwell times necessary to operate the blended system with acceptable reliability, level boarding is an operational imperative for Caltrain. The most important thing to realize is that Caltrain will eventually have to rebuild every single platform system-wide -- if not to the same height as HSR, then to some other significantly greater height for level boarding than the current 8-inch standard.  Level boarding is not just an option; it is a necessary expense without which blending Caltrain and HSR will fail.  Every platform must be rebuilt no matter what; this is the premise from which the rest of the discussion must start.

Q. But why insist on compatibility with HSR platforms?  Caltrain and HSR are separate systems serving separate markets, so why is this compatibility thing such a big deal?

A. Compatibility with high-speed rail is important for two major reasons.

First and most importantly, the San Francisco Transbay Transit Center will be a system-wide bottleneck for both Caltrain and HSR, with just six platform tracks.  This cramped but critically important terminus will be even more constrained if the two operators are forced to use segregated platforms.  In a segregated world, opposing flows of arriving Caltrain and departing HSR could conflict in the station approach tracks, triggering cascading delays should even one train fall behind schedule.  With platform compatibility, any arriving train can be routed to any available platform, minimizing the domino-effect of delays.  The Transbay designers know this issue is the Achilles' heel of the entire design, which is why they are pushing Caltrain and HSR towards compatibility.  The risk of an occasional equipment failure or medical emergency causing a system-wide meltdown depends on the probability of such an incident, combined with the underlying resiliency and flexibility of the infrastructure.  A segregated Transbay design is asking for trouble when things don't quite go according to plan.

Secondly, compatibility has enormous cost advantages for sharing station infrastructure, as will be seen below.  The savings from sharing station infrastructure at just four locations along the peninsula (Transbay, Millbrae, Redwood City and San Jose) could easily exceed the combined cost of converting Caltrain to high platforms system-wide.

Compatible platforms if operated carefully will not interfere with HSR security or fare collection methods.  They are solely a means to maximize the utility and robustness of the Transbay Transit Center and to reduce the capital costs of building California's HSR system by about a billion dollars (yes, with a 'B').

Q. Why can't HSR just select a train design with low floors?

A. It's not that easy.  The CHSRA has expressed an understandable preference for service-proven designs, to draw from the widest range of suppliers worldwide.  Very-high-speed trains (VHST) capable of speeds greater than 200 mph typically do not have low floors.  Nearly all high-speed train designs from Europe, Japan and China for the past several decades have featured high floors, with  few exceptions.  To achieve level boarding as mandated by the ADA while still drawing from the greatest possible selection of vendors, high platforms are almost a necessity for California's HSR system.  The only 200+ mph train with a "low" 30-inch floor is the Talgo AVRIL prototype, still in development.  It does not have distributed traction, which will be important in California's mountainous terrain.

The three foregoing questions allow Caltrain's entire range of possible solutions to be encapsulated in one simple flow chart:


Notice that ALL the level boarding solutions require dual level boarding, at the 8" legacy platform height and at whatever new level boarding height is selected.  Dual level boarding is not an easy problem to solve and usually involves some degree of awkward and clunky mechanisms, be they deploying steps, wheelchair lifts, automatic trap doors, or double sets of doors.  Even the supposedly "simple" level boarding scenario at 25" suffers from this complexity, a fact that is either glossed over or completely misunderstood by most advocates of this solution.

Q. So who cares if Transbay is so constrained?  Can't Caltrain just terminate whatever overflow traffic doesn't fit at the 4th and King terminal?

A. Emphatically, No!  Transbay is a key destination that every Caltrain must serve, especially at rush hour.  75% of Caltrain riders are commuting to work, and there are more jobs located within a 1/2 mile radius of the Transbay Transit Center than within a 1/2 mile radius of all other Caltrain stops from 4th and King to Gilroy, combined!  This enormous concentration of jobs in the heart of San Francisco will only increase with the many new office towers going up today.  Terminating even one Caltrain short of this gold mine of ridership would be quite simply counter-productive, a waste of taxpayer money and a failure to meet obvious demand.

Q. Do you understand the enormous effort and cost to do this?

A. It is a large expense, but also a necessary expense.  The cost of raising platforms is not strongly sensitive to height: rebuilding to ~48" is only slightly more expensive than rebuilding to 25", 30", or any other level boarding height.  Rebuilding to the same boarding height as HSR creates an opportunity to have the high-speed rail project defray some of Caltrain's expense for the conversion to level boarding.

The cost of totally rebuilding every platform is generously $10 million per platform, placing Caltrain's system-wide level boarding tab at (very roughly) $10 million/platform x 2 platforms/station x 32 stations = $640 million, less than half of the cost of the modernization project. On the basis of cost per minute of trip time saved, level boarding beats electrification.

Q. Doesn't this whole issue just boil down to a San Francisco Transbay problem that should be solved at San Francisco Transbay?

A. No, this is not just a Transbay issue.  Rebuilding to the same interface as HSR also enables savings of more than a billion dollars where station infrastructure can be shared elsewhere:
  • The massive dual-level elevated station, the six-mile approach viaducts, and the "iconic bridge" in San Jose would no longer be required, with platforms shared at ground level within the existing footprint of the Diridon station.
  • Squeezing a fourth track under the Millbrae station, requiring hundreds of millions of dollars of tunneling expense, would no longer be required.
  • A Redwood City HSR station, configured to provide HSR service to the booming northern end of Silicon Valley, to enable Caltrain to make cross-platform transfers from locals to expresses, and to tie in future Dumbarton Corridor service, would have a much reduced footprint and would more easily fit in the available site.
Factoring in these infrastructure savings, the cost of converting Caltrain to ~48" is actually negative.  It would be unwise not to do it.

Q. Won't rebuilding all the platforms take years and be an operational nightmare?

A. It will take years, but it can happen with relatively little disruption.  Over the past 15 years, Caltrain has rebuilt 37 platforms from the ground up.  Caltrain has a demonstrated track record for planning, funding and executing platform reconstruction projects.  You'll be hard pressed to find anyone who remembers this causing major disruptions.  EMUs with dual height boarding would considerably simplify the logistics of rebuilding platforms, since each station could be rebuilt independently as funding becomes available and as the planning process progresses in each community.

Q. Will Caltrain end up with a mix of high- and low-level boarding platforms, perpetuating this strange dual boarding height situation forever?

A.  No.  The lower set of doors has only one temporary purpose: to enable boarding from 8" platforms during the transition.  All platforms would be rebuilt to ~48", and boarding from the lower level would ultimately be discontinued.  Any remaining 8" platforms would become an impediment to the blended system, because they would introduce longer station dwells with a significant probability of unplanned delay when boarding or alighting persons of reduced mobility.  Making a mess of the timetable will no longer be tolerable, so there will be a strong incentive to finish the job even at minor Caltrain stops to ensure the highest level of punctuality and system reliability.  This makes Caltrain very different from MUNI or some East Coast commuter railroads, where a mix of boarding heights has persisted for decades because there is no operational imperative for 100% level boarding.

Q. Until all platforms are raised, wouldn't accessibility and dwell time be worse than they are today?

A. No.  EMUs with dual sets of doors would board from 8" platforms with the same efficiency as Bombardier cars, with just two steps up from the platform into the lower level of the train.  (Note that trap door designs would not fare nearly as well in this respect!)

Q. Won't dual sets of doors cause passenger confusion and long dwells?

A. Boarding the train will be obvious, based on which doors open.  Alighting requires queuing at the correct door, which can be facilitated by color-coding of the doors, LED displays, and audible messages.  "Next stop, Menlo Park.  The blue doors will open.  (...)  Next stop, Palo Alto.  The yellow doors will open."  Blue and yellow are good contrasting colors that can be distinguished by color-blind passengers.  People aren't stupid, and should someone get confused, the different doors would be within a few steps and within sight of each other so any mistakes would not lead to significant delays.

Q. Won't all these extra doors displace seating areas and reduce Caltrain's seating capacity?

After conversion to level boarding,
blue doors are plugged and replaced with seats
A. Not necessarily.  Caltrain has estimated that dual sets of doors would displace between 78 and 188 seats per train, or roughly 15 to 25% of a train's seating capacity.  This is a temporary situation during the transition to level boarding, and can be mitigated by procuring extra-wide trains with 5-abreast seating and longer 8-car trains to preserve overall seating capacity.  The space lost to extra doors can be used by standees, who do not have many good options on today's Caltrain fleet.  When the platforms are all converted to level boarding, the lower doors can be removed and additional seating can be installed, especially if this feature is designed into the new EMUs from the outset.

In the meantime, to minimize the loss of seating capacity, it would make sense for Caltrain to make seating capacity a selection criterion in the vehicle procurement process.

Q. Wouldn't this create an accessibility problem, in terms of ADA compliance?

A. No.  Just like today, lifts or bridge plates would be required to board persons of reduced mobility from an 8" platform.  There would need to be an in-vehicle wheelchair lift to change levels inside the vehicle, to allow wheelchair users to board and alight at stations with different height platforms, or to avail themselves of an accessible bathroom on the lower level.  This is not a new technology; these off-the-shelf mechanisms are no more complicated than the exterior lifts used on Caltrain's gallery cars.  An example of such a lift can be seen in this video.

Q. Will bicyclists have to navigate interior vehicle steps, potentially while the train is moving?

A. Yes.  These steps could be made wider and shallower (greater tread depth) than anything in today's Caltrain fleet.  The three steps from a 25" lower level to a 48" mid-level floor could be fitted with wheel gutters to allow bicycles to easily roll up or down along the stairs.  This would make the steps far easier to navigate than the four steep steps up from an 8" platform into a 45" gallery car, turning the corner around a pole through a crowd of Giants fans--the scenario that Caltrain bicycle riders are forced to contend with today.  And riders commonly lift, turn and sort their bicycles by destination while the train is moving, so a bit of jostling isn't exactly a new thing for the bike crowd.

Q. Wouldn't trap doors resolve this whole situation with dual doors?

A. No.  Trap doors have numerous flaws, including one fatal flaw: they would preclude Caltrain passing high platforms at speed while still maintaining an ADA-compliant 3-inch gap when stopped at a high platform.  Trains sway from side to side when running at speed, and the alignment between the track and the platform edge isn't perfect; that means the space between the train and the platform needs to be wide enough to prevent platform strikes but narrow enough to comply with ADA rules.  There is currently no rail system in the United States that can do both: there is either a speed limit when passing platforms (e.g. BART) or the gap when stopped is greater than 3 inches (e.g. Northeast Corridor).  Satisfying both constraints (< 3" gap and 100+ mph past platforms) requires a small bridge step to extend from the train when stopped.  This sort of gap filler mechanism is unlikely to be compatible with a trap door configuration.  Trap doors have other disadvantages, such as increased dwell times while the trap door mechanism is moving, sensitivity to damage from dirt buildup and foreign objects commonly found on train floors, and too many steps up from a low platform during the transition period.

The Takeaway
  • Level boarding is not just an option; it is an operational imperative for the blended system.  The blended system will not work reliably without it.
  • The new EMU vehicles must enable Caltrain's transition to level boarding, or the chance to convert to level boarding will be lost for another 30+ years, the life span of the new train fleet.
  • It is appropriate for Caltrain to adopt the same platform height and width as HSR, in exchange for the funding to achieve the transition to level boarding.
  • Transitioning to level boarding is complicated regardless of the chosen platform height; there is no easy solution.
  • Dual doors are the path to level boarding with the fewest flaws, under the imposed constraint of high-platform HSR.

71 comments:

  1. A note about the Avril: It actually has a higher power/weight ratio (by about 50%!) than many other very high speed trains. But it hardly matters - Talgo is the only manufacturer with a low floor very high speed solution even under development.

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    1. Not really; one can definitely count the TGV 2N types as "low floor" as well.

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    2. Sort of... those trains have steps down into the lower level. And on the scale of the worldwide HST fleet, they are a very tiny slice of the pie, despite their increasing numbers.

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  2. Amazing how this wonderful path of electrification and the blended plan just leads to all these complications and expenses.

    Just what is a prior priority? Are rebuilding of the loading platforms to take precedence over grade separations?

    Pretty cavalier to just add $600 million to the present "modernization" project, which is now pegged somewhere in the region of $1.7 billion. Add another $3 - $5 billion for grade separations and extra passing tracks (no doubt to end up being a full 4 track system), and 2.5 billion for the TBT tunnel and we are talking pretty big dollars.






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    1. It's this or $10 billion of peninsula BART. Pick your poison!

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    2. $10B for peninsula BART sounds pretty good. Is there any chance of that happening at this point?

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  3. You're spending too much time worrying about the transition and not enough worrying about what comes after. With dual height doors, half the doors are useless after the transition is complete. In contrast, with trapdoors, or with raising the platforms half a platform length at a time, you get an annoying kludge during transition, but smooth operation with all doors opening after it.

    By the way, during Fairmount Line reconstruction, the MBTA spent $6 million on raising platforms at some stations.

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    1. Read through please. The low doors would be removed after the transition is complete. As for traps, they have a fatal flaw as described above.

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    2. SEPTA is spending almost 18 million on Exton Apparently it includes the new parking. Very likely environmental remediation. And enough space to re-lay the fourth track sometime in the future.....SEPTA....

      http://septa.org/rebuilding/station/exton.html

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    3. Clem: alright, but you're still looking at a globally unique door plan, if the plan is to have two doors per height per side per car. The Omneo would not work as well for this, because it doesn't have as many usable doors per unit of train length.

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    4. Why not have the bridge step extend from the station platform?

      That said, I prefer the half platform length option.

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    5. I don't like globally unique any more than you; it's just where I ended up based on the assumptions and constraints of the problem. Where in my flowchart did I make a wrong turn?

      @Anon: please do expand on the "half platform length option." How would this work?

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    6. How about raising all platforms one or two car lengths at a time starting from, say, the south / locomotive end?

      During the raising, you continue running today's cars, stopping the car doors short of the raised (or being raised) south end.

      As soon as you have one (or two) car-lengths of all platforms raised, you can begin running trains with one (or two) new high platform cars. These cars must be spotted at the high south end while the others are on the original un-raised platforms.

      Then you begin raising the next one or two car-lengths of platform working your way north from the already-raised south end.

      As you have that round finished, your trains can now carry more new cars at the south end and less old at the north end ... and must on a station-by-station basis be stopped such that the transition between new and old cars lines up (more or less) with the transition beween raised and original-height platform. This is accomplished with the same type of "stop here" signage in use today -- which gets moved each time more of the platform is raised.

      After enough rounds of this, you have transitioned to where you can (must!) run trains of all new high platform cars and your stations are all converted.

      Now, one big assumption for this to work is that there has to be a way run mixed consist trains. Ideally such that passengers can pass between new and old cars coupled together. Otherwise you would be unable to move between the new and old parts of the train. Initially the new part would only be one or two cars, and toward the end the new part would be most and then all of the train.

      Since the EMUs will probably be delivered over time, this might kind of work with the delivery schedule and would FORCE Caltrain to do the platform raising at a good pace since you couldn't run full length 100% new electric trains without having fully (or nearly so) raising all platforms the train is to serve.

      This also ensures that, as some have worried, we don't have a situation where some platforms take forever to get raised as the 2-door height cars would allow.

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    7. There are a number of issues here.

      1) making the imminent fleet renewal interdependent with extensive new platform construction is not gonna fly

      2) inter-operation (mixing within a consist) between old and new fleets is a big and unnecessary complication

      3) "Forcing" Caltrain to do anything doesn't work. They need to have the idea internally and run with it.

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    8. With "half platform length" I was referring to Alon's suggestion of "raising the platforms half a platform length at a time". I don't know how it would work in detail, but I suggest that caltrain could run shorter trains more frequently.

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    9. Or they could do whatever it is that SEPTA does.... SEPTA.... when they raise platforms.

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    10. Well, SEPTA uses trapdoors.

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    11. SEPTA manages to build level boarding once or twice a decade.....

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    12. Actually the newest cars in the NJ Transit fleet -- the doubledeckers -- already have the 2-door scheme. One for level boarding and one for low platforms. So this is not unprecedented.

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    13. All four doors open at stations with high platforms

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  4. Q. Do you intend for every Caltrain platform to be rebuilt?

    No, of course not. Otherwise, Caltrain would have done it by now.


    Q. Why can't HSR just select a train design with low floors?

    Because the TGV Duplex was eliminated from consideration by CHSRA.


    Q. So who cares if Transbay is so constrained?

    Nobody...apparently.


    Q. Will Caltrain end up with a mix of high- and low-level boarding platforms, perpetuating this strange dual boarding height situation forever?

    Yes.


    Q. Until all platforms are raised, wouldn't accessibility and dwell time be worse than they are today?

    Well, duh!

    Q. Will bicyclists have to navigate interior vehicle steps, potentially while the train is moving?

    Yes.

    A. These steps could be made wider and shallower (greater tread depth) than anything in today's Caltrain fleet. The three steps from a 25" lower level to a 48" mid-level floor could be fitted with wheel gutters to allow bicycles to easily roll up or down along the stairs.

    Wheel gutters? Ha ha ha ha!!!!




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    1. Snark aside, what's your better alternative?

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    2. It wasn't intended as a snark. I just think the dual-height door proposal is ridiculous. Since it is highly unlikely Caltrain will rebuild many of the platforms, this proposal is a step backwards from what we have today.

      As for a better alternative, I think you already know what that is: the European TSI spec for 550/760mm platforms. The only reason TSI platform height isn't considered for the HSR trains is for political reasons. And now you are proposing a technical solution for a political problem. That just never works (as we are seeing).

      So my better solution is for the new highly-paid Caltrain CEO to use his political contacts to fix a political problem. Since he has served as Vice-Chair of the CHSRA, that shouldn't be too difficult.

      But as a plan "B", then let me point out that boarding a 1250mm HSR train from a 760mm platform at the Transbay Terminal is not the end of the world. It is a much "less worse" solution compared to the dual-height door nonsense. Normally we prefer level-boarding because of dwell-time issues, but with CHSRA planning on having HSR trains sit around the SF terminal station for 40+ minutes, dwell-time just isn't much of an issue.

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    3. I don't agree. ADA requirements for commuter and intercity rail are really vague and inconsistent. I can point to any number of rail stations being built in Calif. which aren't level-platform. This is especially the case if the Transbay Terminal is merely considered an extension of an existing Caltrain line.

      More importantly, however, ADA requires planners to use the scheme which inflicts the least amount of inconvenience for wheelchair users. The 2-door proposal would require using an internal lift for most Caltrain wheelchair users. My alternative requires less use of the lift for fewer wheelchair riders.

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    4. I see your point and I agree that Plan A would be technically superior, but I don't share your optimism about how easy it's supposed to be to fix a "political problem". Maybe you also have a point that advocating for Plan B weakens the support for Plan A, but I worry a lot that we might end up with Plan C: no level boarding for Caltrain.

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    5. Older comment with typo was deleted

      @Drunk Engineer, I think you are falling into the mindset that "if it comes from Europe, it must be better", ignoring choices countries outside of Europe made. Most HSR are on dedicate lines, sharing tracks with conventional trains only when it is cost prohibitive to do so and treated as an exception, not the norm.

      As for why TGV Duplex is eliminated from consideration and why EMU is required for California HSR, I think Clem already explained this.

      Choosing the European TSI platform height is a non-starter for a new HSR line and would not save Caltrain any money as Caltrain will raise the platform height no matter the choice is 25'' or 48/51''. Also, I don't think there is any requirement for wheelchair to be able to traverse the entire trainset, so the internal wheel-chair lift may not be necessary on all cars and steps.

      I should stress that not all cars in an EMU set need to be in the same car shell, single-level and bi-level cars can form a EMU trainset if they are designed to do so.

      Duel-height-door EMU is a fine choice. Caltrain can either order 20-year life span cars and replaced them with new cars once all platform are raised, or the lower doors can be plugged during overhauls. Raising the platform half at the time is also fine, but still running into the problem that Caltrain cannot raise even parts of the platforms in a short period of time even with good coordination.

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    6. I don't think there is any requirement for wheelchair to be able to traverse the entire trainset, so the internal wheel-chair lift may not be necessary on all cars and steps.

      49 CFR 37.42 states: "individuals with disabilities, including individuals who use wheelchairs, must have access to all accessible cars available to passengers without disabilities in each train using the station."

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    7. That doesn't say every last nook and cranny has to be accessible.

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    8. @Drunk Engineer, the rule does not say disabled-person needs to be able to traverse the entire train. Amtrak California's California Car will obviously violate this since disabled-person space is provided at the lower-level, with no lift to upper-level provided to allow the person to access the passage way to the next car.

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    9. @Drunk Engineer: low boarding bilevels definitely do not allow wheelchair users to traverse the train.

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    10. William,
      The ADA rule says disabled persons must be able to access all cars. So no, that does not necessarily mean being able to "traverse" an entire train, but it does mean being able to board all cars. Thus (if I understand it correctly) your idea that not all cars would have lifts just is not ADA compliant.

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    11. They roll on from the level boarding platform.

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    12. @Drunk Engineer, I search online and found that each car needed to be wheelchair accessible is a fairly recent standard, otherwise trains that run with Gallery cars would violate this.

      Also from online searches, I found that for new vehicle/system to meet the ADA requirement, at least 60% of the entrance needed to be ADA compliant, i.e. level boarding, wheelchair lift, mini-high platform w/bridge plate, etc...

      Just a thought, if Caltrain adapted a 3-car or 6-car fixed EMU set with open-gangway, would each set be treated as one "car" with respect to ADA compliance and thus not all car in the set needed to be ADA accessible? Just like some newer light-rail vehicles?

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    13. Interesting question on the open gangways making each trainset "one car" from the inside for ADA compliance purposes.

      My guess is ADA didn't cover or anticipate this open gangway question ... on the one hand, if aisles were and gangways allowed a chair to roll from end to end, it may allow one to argue it qualifies as one car for ADA purposes. However, if a chair wasn't able to exit from any door, one could argue that making the chair roll all the way back to an accessible door for normal or emergency exit, that goes against the spirit (if not the letter) of the ADA.

      The best way to try to avoid this fight is to have all the interior wheelchair parking as close as practical to an accessible door ... or just make all doors accessible anyway!

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  5. Proof of payment vs fare gates? What is the CAHSR's plan for fare collection? If they build fare gate, does Caltrain follow the same path?
    If each system have different fare policy, platform cannot be shared.

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    1. While POP is not easily made compatible with fare-gate systems that CHSR is expected to use, tag-on/tag-off on train doors with smart fare mediums (RFID fare storage cards, QR code tickets, etc...) can easily be integrate into a fare-gate system, i.e. high throughput station can tag/read tickets at fare-gates, while smaller station would use on-board readers.

      Hopefully Caltrain would give this a thought, as it should not be a big leap after the Clipper adaptation.

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  6. So .... moving and raising steps are too complicated and failure prone, we read here.

    But yet the solution is ... an entire duplicate set of (failure-prone!) doors, which will certainly come with a whole set of structural compromises (weight and performance for sure, fleet reliability and availability for sure, and perhaps even fleet reliability after the transition is complete due to compromised car bodies), and yet don't provide level boarding any way.

    I don't get it.

    If you're going to go with pre-1980 high floor retro trains (and you're going to say HSR will never be double deck), then just man up (crazy disco era man!) and go with the retro moving steps -- if not quite as far as going with super-retro "trap doors".

    The retro steps are easy enough to remove when they're not needed, they have no permanent significant structural effect on the train bodies, they don't take away large amounts of interior space for redundant vestibules, they already exist and are already deployed in multiple designs.

    Lots of doors = lots of downsides.

    And the station platform transition plan -- unlike your earlier one with the wide train 30 inch level boarding for everybody -- sucks, and will suck for decades.

    I don't get it.

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    1. I just don't buy that double the doors will result in half the mean time between failures.

      The reliability of any individual door mechanism is not measured in MTBF, but in mean door cycles between failures. It doesn't take a reliability engineer to figure out that if each station stop involves cycling only two doors per car (either the high doors or the low doors, never both) then the overall reliability of the train will be no worse than a normal design with only one pair of doors.

      Doors actuators are a very mature technology, hardly the weak point in a train design. Unlike moving steps, every train design has them. If you think they drive fleet availability, there must be an RGI article that you can point at to back it up, and several metro operators with systemwide meltdowns.

      Don't get me wrong: 30" would be great, but I just don't see HSR meeting Caltrain halfway. Someone said it was politics. I don't know how to solve that. Do you?

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    2. Thanks, Clem, for your always thorough analysis and explanation of HSR/Caltrans platform compatability. Are you, in any way, related to Clem Kadiddle-hopper? (^:




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  7. I've been thinking about this post for several days, and I think it's ultimately wrongheaded. Just buy high level equipment, sell the existing low level equipment and call it a day. This is harder to do piecemeal but it can be done. There is a robust resale market for the Bombardier cars and nobody wants to keep the Gallery cars running anyway. This rather than two level boarding gives the best outcome after the (brief)transition period.

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    1. How long would it take to erect temporary high platforms at all stations?

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    2. But that is precisely the problem: you have not detailed a viable transition plan. You have waved your hands over this complicated issue.

      There is a similar trap that advocates of the 25" level boarding solution so often fall into: they have no transition plan. They think it's obvious. They think (without thinking quite hard enough) that an EMU with low doors can serve an 8" platform at one stop and then a 25" platform at the next stop. That's not feasible without moveable step gizmos, invoking all the complaints about complexity that are leveled against this 48" dual boarding height approach.

      You basically ignored one of the key constraints of the problem: there is no money available for short-term platform reconstruction.

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    3. I think the platforms could all be raised to 48" for around $200m if the project isn't combined with every other upgrade Caltrain can think to do (64 platforms, 72,000sf each at ~$40/sf + contingency). This is a sizable project, but one that could be done quickly (say over 2 weeks). I think that the expense of platform upgrades will have to be paid eventually anyway and that doing this avoids running oddball equipment for decades. Could 4 door trains be built and work OK? Sure. But why mess with them when you could just have the project done.

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    4. The temporary platforms are but a downpayment on the permanent platforms. And it's not clear how you would operate during the fleet transition: do you wait until all the EMUs are delivered to begin high platform service? Can you operate a mixed fleet? If so how do you tell passengers where to wait for the next train? How long do the temporary platforms stay? How do you handle tight locations like Menlo Park or San Mateo? And two weeks?!?

      A dual boarding height train avoids all these problems. No temporary platforms. No constraints on construction timelines or budgets. No complicated fleet phase-in issues, no problem mixing and matching. That flexibility is well worth a slightly funky vehicle configuration.

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    5. One way to quickly build platforms would be to pre-fabricate offsite as (say) 4'x4' modules made from galvanized steel. The installation would be rapid since all you're doing is moving them into place and lagging them down (yes, you would have to do some site prep, but this isn't outside the realm of what can be done). Such modules could have thin concrete tops (as some exterior stairs do) and would last for decades. As for the two week period I described, I'm suggesting a complete shutdown. So, no awkward transition period at all. Just the current crappy operation one day and 2 weeks later modern operation.

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    6. something like that, but I would use more lightweight materials. Built prefab modules of coated wood and Styrofoam. Large so you would need few of them as possible, but small enough so you could load them on a train wagon and a 'normal' crane can easily put them on today's 8" platforms.

      If you start looking at this problem from the flow of travelers you would see that with adapting the Baby-bullet station-platforms first the necessity for dual-height doors would almost half. For these few train station large platforms are probably necessary and a stop gap solution wouldn't be good enough, but it should be possible to adapt these platform concurrently with ordering new EMU's.

      The rest of the platforms you could built level boarding with prefab stop-gap elements, and slowly transform these stations in the next years.

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    7. Okay, Polystyrene if you want. See par example http://www.networkrail.co.uk/news/2014/feb/Modular-polystyrene-platform-installed-at-Peterborough-station/

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    9. All styrofoam is polystyrene. Not all polystyrene is styrofoam. Modelers uses polystyrene sheet, as a rigid yet easily-cuttable and gluable material.

      For those who don't know: Peterborough is on the East Coast Main Line, former stomping-grounds of Gresley Pacifics (A1, A3, A4 (Mallard)) Deltics, and HS125 trainsets. Rather close to Cambridge (England).

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  8. Been thinking about this one for a while and have a random question that Clem or those more familiar might be able to address: why were you so quick to dismiss a combination of trap-door / moving steps WITH extending gap-fillers? Muni Metros have exactly this: the steps raise and lower to handle street level and platform boarding, and ALSO have a two inch gap filler that extends at platforms. I'm sure over the full life cycle of a train this would be problematic, but given that its a transition-period-only thing, it seems the tech exists to build them such that they are reliable at least until they are no longer needed... no?

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    1. First, I believe MUNI cycles their steps once per run at the Market St. tunnel portal. Cycling them at every stop seems like it would invite additional dwell time delays and breakdowns, keeping in mind that those steps are already one of the leading causes of breakdowns on the Breda cars. To me, that seems like asking for more trouble than an extra pair of bog standard doors...

      Second, this design would have more steps into the train when boarding from a legacy 8" platform.

      Third, it's not clear that it would work from a vehicle packaging standpoint for a bilevel railcar design: you would no longer be able to place the doors over the wheels (due to the traps) so you would either end up with a NJ Transit-like narrow door at the ends of each car, or with a single level car. Again in my opinion that seems even more sub-optimal than two pairs of doors.

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    2. Interesting, makes sense. On cycling, MUNI does cycle a bit more frequently -- any time a disabled pax or stroller at any stop needs to board they cycle the steps up and back down, while caltrain wouldn't cycle at *every* stop -- only where the platform height changed from one stop to the next. And MUNI cars proabaly (guessing here) average 3-4x as many runs per day as caltrain. I'd hope as an interim plan (allow say ~10 years to raise all platforms) it could be reliable mechanically... the Bredas are approaching 20 years after all. Still, totally fair point.

      The packaging / wheel point is the most compelling to me, and I had totally missed it.... Having ridden Boston's commuter rail for years and dealt with the narrow doors I totally get your point, especially on a system that allows bikes...

      Thanks for the thoughts!

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    3. Trap door is definitely not a good solution, but have to say that Clem is overstating the problems with door/wheel layout. Using an articulated train (which Caltrain should be doing anyway) would put the doors away from the wheels. The Bombardier Regio 2N is one example.

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    4. Quite true, and I had even suggested the Regio 2N / Omneo wouldn't be half bad for Caltrain. But could the conductor's union really handle the redefinition of what the word 'car' means, as far as staffing levels are determined? Besides, this new-fangled articulation thing is highly suspicious, almost un-American.

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  9. +1 for articulated trains ... the US transit industry seems to have adapted to articulated buses just fine, so I think the train workers' unions will figure out car boundaries are at the bendy places instead of by counting bogies (wheel trucks).

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  10. Once Plan B is fully implemented and low level doors are replaced with seats so only high level doors remain, how will evacuations work? For example, I was on a train that hit a car back in 2011. Our train remained stopped and eventually another train arrived on the other track and we conductors made us go from one train to the other. With all high level doors, would passengers need to wait for Caltrain to bring over steps, or will there be a ladder or can we just "jump" down?

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    1. It would likely be even easier. Another train will pull up alongside the disabled train, and they will place a bridge between the doors. You then just walk across.

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    2. Maybe you should ask one of the dozens of operators around the world (and many in the US) that operate railcars with only high doors.

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    3. The tracks are often separated by too great a distance or other obstacles to make @Peter's "bridges" a workable solution.

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    4. Who told you so, Mr. Reality Check?
      http://img.47news.jp/PN/201501/PN2015013001001464.-.-.CI0003.jpg
      http://www.47news.jp/CN/201210/CN2012101201000881.html

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    5. @Anonymous, I'll help you by spelling it out more clearly for you: @Peter was talking about a train pulling up alongside a disabled high-level Caltrain ... whose tracks are often separated by too great a distance or other obstacles to make on-board "bridges" a workable solution to evacuate train-to-train everywhere a train might break down.

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    6. Where are the tracks so far separated that bridges wouldn't work?

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    7. Here's a spot. Finding others is left as an exercise for those with too much time on their hands.

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    8. They could also tow a disabled train to the next station. Caltrain will still have switchers for this purpose.

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    9. Nobody said it wasn't an unsolvable problem. Bridges won't work everywhere.

      As long as power isn't out, any train can push a disabled train ... no need wait for a diesel switcher to be fired up and trundle over to where it's needed.

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  11. (... was an unsolvable problem) Yawn. What a fascinating conversation.

    Surely there must be a way to keep it going. Sigh.

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  12. I actually think that the most likely scenario for wheelchair access would be to use the high doors for ALL wheelchair access, requiring a lift at all low-level stations, but not requiring a lift inside the train. Annoying but only true during the transition period.

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