A Train Station Grows At Transbay ... (pt. 1)

by BruceMcF Thu Apr 16th, 2009 at 04:27:59 AM EST

... Hopefully it's not a Bonsai

Burning the Midnight Oil for Living Energy Independence

I was able to get an interesting look into the proposed future of Intercity Travel in the Bay at the Transbay Terminal (TBT) in San Francisco.

Senate Info Hearing on High Speed Rail in California

Note that I am not trying to give "objective reporting" on this issue but rather to give vent to my reaction to watching the hearing online ... see The Troubling Discord Between Transbay and High Speed Rail Authorities for a less hot under the collar reaction.

One piece of information is that in California, when one public authority has the funding for sufficient staff and another doesn't, and it comes to a fight, it is considered fair game for the staffed up authority to toss up spin and red herrings and biased analyses, confident that the other authority does not have the capacity to answer promptly.

Diary Rescue by Migeru

Part 3, which considers the option of operating the Transbay Terminal as a through-service terminal rather than as a route terminus, was already posted on the European Tribune, here.

The Players

The Transbay Terminal is a transit/development project, so they have their own organization, the Transbay Joint Powers Authority. They have a staff of seven, including a principle engineer.

The California HSR Authority (CHSRA), is the small commission that has been responsible for pushing the California HSR through the planning phase. According to their testimony at the meeting (I think it is the executive directory, Mehdi Morshed), two years ago, they were pushed into doing everything possible through contractors, and they only have a staff of three, and it would seem do not have a principle engineer. They are also completely broke ... they have been running on IOU's to their contractors, because of the California state budget crisis, and are waiting on bond sales to be cleared to be able to actually pay some bills.

Caltrain is the rail service that runs between San Jose and San Francisco on right of way and track that was bought from a former private owner. They operate under a board of directors with three members representing the city and county of San Francisco, three members representing the San Mateo County, and three members representing Santa Clara County.

So north to south along the Caltrain line, that's San Francisco, Silicon Valley (San Mateo County), and San Jose (Santa Clara County). The representative from San Mateo and Santa Clara are from area transit authorities.

The Old "Ambush At The Hearing" Trick

Late on in the piece is the technical guy from the Transbay Terminal (TBT) project putting in all sorts of arguments against changing the design of the TBT "train box", without concern or regard for whether the arguments would be considered fair or impartial by a disinterested third party.

He compares:

the station stopping time at a through platform to the station stopping time at a terminal platform;
the terminal turn-around for a regional rail service running between San Jose and San Francisco with the terminal turn-around for a long distance rail service for a train that arrived from Anaheim/LA (or even, in Stage 2, San Diego); and
the number of services on single routes in Japan and Europe with the number of services for the main northern terminal for multiple routes in California

In other words, red herring tossed out at such regular intervals that quite a pile has accumulated by the time he's done.

He isn't the only one with tricks up his sleeve ... one of the Senators asked after the terminal capacity at Anaheim. The answer, by the way, was six platform tracks for what is supposed to be the secondary Southern Terminus when the full system is complete ... two more than the TBT proposes for HSR, at what is supposed to be the primary Northern Terminus.

How many HSR services should be allowed for?

On the other hand, the California High Speed Rail Authority (CAHSRA) is making claims that seem hard to buy, with nothing more than "our engineers tell us" advanced to back them up. They seem to have asked for an ability to support 12 trains per hour (tph), with 40 minute platform dwell times, claiming that they need 9 to 10 platform tracks.

Does 12 tph with 40 minute dwell times translate to 9 to 10 platforms? That's 1 1/2 trains per hour per platform, 12 divided by 1 1/2 is 8 in the mathematics that I am accustomed to teaching.

More than that, where is 12 trains per hour coming from? That is a technical requirement for through stations, because the HSR line is designed to permit trains to run at five minute intervals, and along the line, you cannot allow one service to block the next in line.

For the terminal station, the question is the number of services that might start or end at the station. For the California HSR system:

Connecting LA and the Bay is the backbone transport market for the HSR system ... there could well be demand for one LA/Anaheim Express and, half an hour later, one LA/San Diego Express
The Central Valley will be within three hours by an all-stops HSR to both LA and the Bay ... and within two hours of one, the other, or both. So in addition, one all-stations HSR service per hour during the middle of the day is something that needs to be provided for ... bearing in mind that while this is a smaller transport market, the HSR will grab a larger share of the total market
Given one or more Bay/LA Expresses per hour and an all-stops to capture all trip-pairs (even the ones that the ridership modelers neglected), a Semi-Express from SF to San Diego will cater to the transport market of the larger population centers to the Bay and LA.

So this is 4 trains per hour ... 1 train per hour on four distinct services ... without even considering a Fresno special, or a spur at Mojave for Las Vegas.

And when the 400 seat single level, single set trains start filling up, its better for building ridership to first increase frequency before increasing capacity of each train. 2 LA/Anaheim Expresses per hour, Express LA / Semi-Express San Diego, Semi-Express LA / Express San Diego, Local to Fresno, Semi-Express to LA, Semi-Express to Fresno then Local to LA ... and we are already at 6tph, without any capacity to support the occasional special service like a Fresno Express or, if a branch line is added at Mojave, a Las Vegas service.

Twelve trains per hour may be aiming too high, but six trains per hour seems to be aiming for the bare minimum.

Given the massive cost of building more capacity after the original foundation has been laid, the capability for eight (8) HSR trains per hour seems to be a perfectly reasonable expectation for the primary northern terminus for the system.

And its not like the idea of using the TBT as the main northern terminus for an HSR network is a new idea ... San Francisco voters voted for that back in 1999 long before the win on Prop 1A converted it to a project with a better than 50:50 chance of succeeding.

Following the trail of red herring

Now, when someone deploys deceptive comparisons and unbalanced comparisons, I have a reflex reaction ... a pile of red herring is normally used to cover something up.

And that something seems to be is a design flaw.

The TBT "train box" includes two "tail tracks", which allow trains to get off the platform, either for overnight parking or for non-passenger operations like restocking and cleaning, without using up space in the tunnel.

In theory, this means a train can arrive at an arrival platform, unload passengers (which is a very quick operation, since trains have far fewer passengers per door than airplanes), move to the tail platform to make room for the next train, get trash taken out, seats needing deep cleaning looked after, food and beverage restocked, and then get moved to the departure platform.

And the TBT tunnel access is designed with three tracks, which eliminates all sorts of potential bottlenecks:

Both Caltrain and HSR services arrive in the TBT on the central track. At the speeds they are traveling, trains running at three minute intervals is a commonplace occurrence around the world, so one entry track can certainly support up to 20 trains per hour total ... 24 if the signalling and switching can support two and a half minute separation, as in some busy tunnels on the East Coast.
A Caltrain service departs from the Caltrain island platform using the "inner" tunnel track, which opens up the platform for an arriving Caltrain service
After the departing Caltrain service has left, the arriving Caltrain service switches over to the "inner" track to get to the Caltrain island platform
HSR services run directly to the central arrival island
HSR services unload, go to the tail track for restocking and clear the arrival platform for the next service, then go to the departure platform, then depart using the "outer" tunnel track

This is a system that allows three different islands to be accessed with little interference, because only two islands get incoming trains, and because each type of service has its own dedicated departure track ... so they can arrive in sync, dwell in station for different lengths of time, and leave on their own schedule.

In particular, it allows the HSR trains to be in the station for over 40 minutes, while only occupying the platforms for 30 minutes each, raising the capacity of four platforms to eight trains per hour. Voila!

This also makes it easier to organize efficient movement of passengers, since passengers are either leaving or arriving at each HSR platform ... there isn't a problem at the platform level of departing passengers getting in the way of arriving passengers.

So with this, four platform tracks support can support 8 trains per hour, with 40 minutes station dwell time per train ... which is to say, while not extremely ambitious, adequate to the needs of the planned HSR system with enough spare capacity to allow for growth.

The Design Flaw

The design flaw may not jump out at you, but its in the sketch, taken from the 2003 "locally preferred option" design for the TBT Environmental Impact Report. The right hand side is the tunnel from the present end of the rail line. The left hand is the turn to the tail tracks.

Now, the HSR platforms have to be designed for long trains ... once the capacity is filled with 8 car, 400 seat trains, they can be extended to 16-car, 800 seat trains, and then by moving to bi-level trains, 1400 seat trains. That means a 1,320 foot long platform. That means that the bottom two islands are for the HSR and the top island is for Caltrain. The bottom two platforms need to be stretched a bit, and the middle one straightened somehow ... but at the hearing, the TBT technical person said that that had all been fixed up.

So, stepping through the pictured design:

Counting access tracks, three tunnel tracks split up to make six platform tracks. So far, so good.
For Caltrain to operate as described above, a switch will have to be added so Caltrain services can get from the middle tunnel track to the "inner" tunnel track which leads to the Caltrain platform. And since the outbound train has to leave the Caltrain platform before the inbound train can arrive, that switch is no real bottleneck.
The two Caltrain platform tracks are connected directly to the Caltrain exit track, so that will work just fine.
For the HSR trains to operate as described above, the central island is the arriving platform, connected directly to the tunnel track that brings trains in. That will work just fine (well, the curves are awfully tight, so they can't move as quickly as they should, but if they are all moving at the same slow speed, they will all be in sync).
That leaves the bottom island as the departing platform. The two platform tracks at this island are connected directly to the HSR exit track, so that will work just fine.
And the tail tracks ... are not connected to the bottom platform track. Instead, the bottom platform track comes to a dead end. That is not just fine. Indeed, assuming that the TBT has the staff that they likely know all of this already, that might be what the pile of red herring is supposed to cover up.

What can be done to straighten up the mess? One approach is to swap the Caltrain platform from top to bottom ... and trim a substantial piece from the front (right hand side) of the bottom platform. In fact, trim enough from the front that the switch between the two platform tracks is after the single tunnel track has rounded the corner.

Note that this is just a rough sketch

Trimming off the front of the bottom island allows the middle island to straighten up. Straightening up the middle island allows the top island to straighten up.

The middle island can be straightened up a bit by extending the tail track directly from the middle platform, with switches switches connecting the top island, which gives more room before the platform track must bend to form the rail track.

This might not be enough for 1320 ft. of straight platform, but it'll be a lot closer ... and, after all, the CAHSRA is probably overstating how much straight platform they need, since the platform only needs to be straight for the passenger car portion. A little bit of bend for the driver cars at the front and rear of the train can be tolerated. If this can get 1200 ft. of straight platform with a 60 ft. curved part on either side, that certainly seems like it ought to be OK.

So, if both sides are wrong, who is going to admit it?

The question that puzzles me the most is not the technical one ... as tight a squeeze as it may be ... but the political one. The TBT authority have made public claims that present a picture of basically being ready to go, except for the fantastical demands of the CAHSR authority. The CAHSR authority has made fallen into the trap of making an ambit claim that they will have to strain to support ... but if that costs them the political argument, the fact that the TBT train box is an inadequate design is likely to be lost in the collapse.

The only player that strikes me as having the opportunity to say, "wait a minute, here's a fix that won't cost all that much to implement" is Caltrain. But ... under the solution above, they are giving up a 900 ft. platform, connected to the tail tracks, for what could end up being a 800 ft. platform, with only one connection to the tail track, and that connection only available when the closest HSR platform track is empty.

To Be Continued ...

Anyway, that's the puzzle. But there's another possibility ... one which might be of more appeal to Caltrain ... so I am going to end this with an ellipses.

...

A Train Station Grows At Transbay ... (pt. 1) | 30 comments (30 topical, 0 editorial, 0 hidden)

Re: A Train Station Grows At Transbay ... (pt. 1) (4.00 / 4)

I read somewhere on the California HSR blog that SNCF may be interested in picking up the operating side, so its of course important to get the northern terminus right.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Sun Mar 22nd, 2009 at 02:11:43 PM EST

Re: A Train Station Grows At Transbay ... (pt. 1) (4.00 / 2)

I see your "Dead Heart" and raise you a "Beds are Burning":

Be nice to America. Or we'll bring democracy to your country.

by Drew J Jones (pedobear@pennstatefootball.com) on Sun Mar 22nd, 2009 at 08:48:40 PM EST
[ Parent ]

Hah! I see your Burning Beds and raise you ... (4.00 / 2)

... Truganini in chains. It even has the word "train" in it.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Sun Mar 22nd, 2009 at 09:44:06 PM EST
[ Parent ]

Re: A Train Station Grows At Transbay ... (none / 0)

Could you expand the intro to better explain the players to Europeans? Whose project is the TBT, what are the opposed interests? (I already had a hard time figuring these out while reading you guys at CaHSR.)

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Mon Mar 23rd, 2009 at 10:42:28 AM EST

Re: A Train Station Grows At Transbay ... (none / 1)

I'm not a Californian, so often who are the players is confusing to me.

Its a bunch of quasi-independent authorities, and each is, of course, trying to play a game of pass the hot potato as far as the cost of the train-box goes. That's why the TBT is trying to leap on the stimulus funds to get money for the train-box ... and also probably why the train-box was under-engineered in the first place.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Mon Mar 23rd, 2009 at 11:15:23 AM EST
[ Parent ]

Re: A Train Station Grows At Transbay ... (none / 0)

No, I am asking about more basic things. I have no time or bandwidth right now to watch the video, so I am not even clear about things like:

which is the authority with money and which is the one without?
is TBT a private, public; wholly independent, or somehow Caltrain- or San Francisco municipal council-linked organisation?
what exactly are the oppsed demands? IIRC one side wants a bi-level train box for more platforms; from the above, it appears that's TBT, but based on CHSRA's demand for 9-10 platforms, it would seem it's them.

Also, a bit of North American terminology: by "platform", you mean something for boarding a train along a single track, right? E.g. half of an "island platform" that is flanked by two tracks?

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Mon Mar 23rd, 2009 at 11:53:27 AM EST
[ Parent ]

Re: A Train Station Grows At Transbay ... (none / 1)

All the players are public authorities under different boards, as described in the update "The Players" in the diary.

North American terminology ... this always trips me up too, since I started riding trains in Oz, which used Commonwealth expressions ... a platform is a physical structure, an island platform will have two platform tracks. Wherever possible I try to say "island" and "platform track" and avoid "platform", but I probably do not entirely succeed.

TBT has money to start building the main building, but not to build the train box. They are trying to get the train box funded out of HSR stimulus funds.

As noted in the update, "The Players", CHSRA has no money at all right now. They are partially bond funded for $9b thanks to Prop 1A, and some of those bonds could be used for overheads and planning, but the bonds could not be sold because of the California budget crisis. The first post crisis state bond sale is scheduled for this week.

Whether CHSRA is seen as having no money, or access to $9b plus, they want to be on the hook for as little money as possible for the access tunnel and TBT train-box itself. Tunneling is expensive, and they have tunneling of their own to do south of San Jose and north of Los Angeles.

As in the update, the TBT is a transit/redevelopment authority, so they are public, operating under an independent board, with most of their funding so far coming from the state, some from the participating cities, very little from the transit-hating Bush administration, and hoping for much more from the Feds.

Claiming that they are a HSR project makes more Federal money possible ... CHSRA does not want that money tallied against their total, since under current economic conditions, they may need more Federal funding than they were hoping for, if they cannot get as much private funding as they were hoping for.

The opposing demands:

CHSRA wants 400m straight platforms, and 9 to 10 of them, and access capacity for 12tph. At least they say they do. What they really want? Unclear.

TBT seems to want a train-box that they can claim satisfies their long-standing local statutory requirement to serve as the terminus for both Caltrain and HSR, ideally without spending a dime of their own money. From the clip, building their original train box design as part of the original structure cuts the projected cost from $490m to $390m. If they can get $390m from the Feds to do that, they'll be very happy.

If the access tunnel can wait for eight years to start building, they are obviously just not going to worry about it, assuming that it can be sorted out closer to the time. By contrast, the California HSR authority is going to want to make sure that their share of the tunneling cost is as low as possible.

The TBT does not seem to see the train-box as something that will substantially increase the property value of the properties they are developing, so from that perspective there would be no incentive to do more than the bare minimum. For Peak Oil, De Nile seems to be more than a river in Egypt.

For the CA HSR authority A train box with an effective capacity of, say, 5 1/3 tph would mean a dramatically different mode of operation, and likely mean when they do their ridership survey a lower projected ridership, which would then undermine the size of the bids they can hope to receive to operate the services. So if I was guessing, they would be hoping to get the main northern terminus that does the most good for their ridership projections, without allocating more than the bare minimum in their budget to it.

A narrower but deeper 2-deck train box, with two side platforms and one island in each level and the mezzanine in between, could offer 6 HSR terminating platforms and 2 Caltrain platforms connected to tail tracks ... which could then be rolled out in two stages, with the mezzanine and lower deck done first, and Caltrain temporarily using two of the platforms intended for HSR, and then the upper deck and tail tracks built, and the lower deck side platforms rebuilt to HSR platform height.

6 platforms is plenty for 40 minute maximum allowable platform dwells (what the CHSRA asked for) and the 8tph access capacity.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Mon Mar 23rd, 2009 at 02:09:08 PM EST
[ Parent ]

Re: A Train Station Grows At Transbay ... (4.00 / 2)

To explain in a bit more detail.

The Transbay Joint Powers Authority is not all that independent. Its board includes the head of San Francisco MTA (an appointee of Mayor Gavin Newsom), a representative of Mayor Gavin Newsom, an elected AC Transit (Oakland-Berkeley-East Bay) board member, a member of the Caltrain board, and Chris Daly, one of the left-wing members of the San Francisco Board of Supervisors.

What this means in practice is that the TJPA board is basically run by elected officials from SF. San Francisco voters have on several occasions approved the Transbay Terminal project and the downtown extension and have created some pools money to do this.

The California High Speed Rail Authority Board is more independent, for whatever value it has (more on this later). Its members are appointed by Governor Arnold Schwarzenegger and confirmed by the state legislature, but the governor has taken a less overt role in leading the board than Newsom has with the TJPA.

These quasi-independent board have a weakness in that they're not clearly personal domains of a powerful figure (whether that's the mayor of San Francisco or the governor of California). So it's not quite as simple as Gavin or Arnold or anyone else coming in and saying "get this done".

In practice the TBT is San Francisco's project and Gavin Newsom has in fact asserted a very strong role in ensuring it gets built. Newsom has not had a big place in the HSR project. If he somehow gets elected governor next year (he is a candidate but I do not expect him to win) then he would be in a commanding position to resolve this dispute by potentially appointing new CHSRA members.

There's also a proposal to create a "Department of Railroads" within state government, to house all rail programs and regulation within that instead of under the Department of Transportation. That would include moving the CHSRA into a Department of Rail. I'm not sure that's the best idea, but it is out there.

There is no opposition to the TBT project. The CHSRA is making this weird "omg we need a second level to the trainbox" argument without really explaining why, at a late date, and the SF political leadership is trying to figure out wtf this is about.

And the world will live as one

by Montereyan (robert at calitics dot com) on Mon Mar 23rd, 2009 at 10:44:41 PM EST
[ Parent ]

Re: A Train Station Grows At Transbay ... (pt. 1) (none / 1)

For the terminal station, the question is the number of services that might start or end at the station.

Let's look at CHSRA's figures in this projection (page 5/pdf page 9). It's only for Phase 1, but at full capacity, and foresees a more complex service pattern than you (one more comparable to SNCF's and JR East's service pattern than say RENFE's). The table for peak hours is formulated a bit confusing about frequency, so I re-calculated it for every two hours and every direction:

(express with multiple stops only in the megapolises): 1 train
(express with stops only in 4 main stations): 2 trains
(semi express, with more stops in the Central Valley): 1 train
(semi express only to LAUS, with evenly distributed stops that include Sylmar): 4 trains
(semi express only to LAUS, with evenly distributed stops that include Palmdale): 4 trains
(semi express, with more stops nearer to LA): 1 train
(all-stations SF-Merced): 3 trains
(all-stations LA-Merced): 3 trains

That's 16 trains from TBT every two peak hours, or 8 every hour.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Mon Mar 23rd, 2009 at 11:07:12 AM EST

Re: A Train Station Grows At Transbay ... (pt. 1) (none / 0)

Thanks for that. I think there is likely to be more ridership than the CAHSR schedule contemplates in the origin/destination pairs in the "tail" of the ridership distribution, especially in the CV, so put more emphasis than they did on building up the all-stations frequency ... but yes, going from a two-tier to a three tier Express, Limited, and all-stops would also add tph.

All of which says that an upper ceiling of 6tph is awfully low ... and the incremental cost of expanding the box, that is, the addition to the cost from doing it in two stages, can easily be greater than the original cost of building the three-island box in the first place.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Mon Mar 23rd, 2009 at 11:31:54 AM EST
[ Parent ]

Platforms (none / 1)

After reading the rest of your diary, I am very much puzzled.

What is the (expected future?) train frequency on Caltrain?
If only two platforms are for departing trains, that means that just to support 8 tph, maximum platform waiting time is 15, not 30 minutes. (For 12 tph, just 10 minutes.)
(Sidenote: a 15 minute period at each departure platform allows for a 40-45-minute train turnaround with uniform 15-minute cycles at each of two arrival, tail, and departure tracks. A 10 minute period at departure platforms would require four tail tracks operating in a - perhaps more realistic - 20-minute cycle.)
I must ask, what is the planned curve radius? For, curved platforms even where you have cars is not at all unheard of, so I am not sure why they require straight platforms. (Below: Cologne main station, and my own photo at Le Mans)

* Those tail tracks must be pretty long already to accomodate 400m trains. Has no genius considered a loop-back through station, at least for the Caltrain part?

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Mon Mar 23rd, 2009 at 11:47:47 AM EST
[ Parent ]

Re: Platforms (none / 1)

In reverse:

* Yes, a loop-back through station was originally a design option, it seems to have died somewhere early in the process, pre-2003. The tail tracks are shallow, cut-and-cover tunneling, I believe they will probably have had to bore to get a loop-back ... the loop-back would be extending well beyond the property being re-developed for the TBT project, so that would be much more expensive eminent domain for cut-and-cover on the turn.

And, yes, the original design spec was to stable four Caltrain trains, two per track ... they tend to run fairly short, but if they get to ten cars EMU, there's the capacity to hold a single full-length HSR set. AFAIU, they run the tail track through to a foundation of a freeway.

I am unclear about the CHRSA demand for 400m of straight platform ... if I was to guess, I would guess that they can not provide detailed specification of what would be an acceptable platform curve radius for the extremes of the platforms (the middle portions are straight in any event because of structural support columns extending through the box to foundations beneath) and so are laying out an ambit claim that is on the safe side.
On turn-arounds (that is, the Sidenote), once I hit arrival, tail, departure station and platform dwells that seemed comfortable to me as maximum allowables, I didn't press it any more. There's nothing I have heard about maximizing tunnel track throughput, and with 3 minute headways, that seemed to me on the access track to be 4 service slots, alternating between Caltrain and HSR, an open slot, repeated four times.

The alternation is because of the trainbox throat track design ... with independent egress track there is no need for Caltrain access to crossover HSR egress, and visa versa, so alternating HSR and Caltrain access means there is an egress slot for each service immediately preceeding each access.

* On Caltrain, I think its about 6 tph, but on the other hand, there are other standard gauge regional rail services being pushed for, and they would of course want to connect to Caltrain as well as to the intermodel (Bus at the TBT, BART a block away) transfers there.

The present Caltrain terminus at 4th and (mumble) would continue to be a Caltrain station, so if Caltrain hits capacity they can always start alternating between services terminating at the current terminus and services terminating at the TBT.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Mon Mar 23rd, 2009 at 01:33:37 PM EST
[ Parent ]

Re: Platforms (none / 0)

Will it be possible to extend the line northwards after this ?

Un roi sans divertissement est un homme plein de misères

by linca (antonin POINT lucas AROBASE gmail.com) on Mon Mar 23rd, 2009 at 08:16:27 PM EST
[ Parent ]

Re: Platforms (none / 1)

There's not really where northward to go, this is downtown SF ... three short blocks and your at the Embarcadero and the piers.

There is the notional possibility to head east in a tunnel under the bay to Oakland, if they dug a new transbay tunnel. Locals from SF on the CA HSR blog seem to think this is not a politic issue to raise at this point in time.

The possibility exists of a people mover to connect underground to the BART stations from the TBT (1/4 mile, a block away) ... its penciled into the designs, but it seems as if without funding.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Mon Mar 23rd, 2009 at 11:38:47 PM EST
[ Parent ]

Re: Platforms (none / 1)

Oh, and on this point

"If only two platforms are for departing trains, that means that just to support 8 tph, maximum platform waiting time is 15, not 30 minutes."

... yes, with three minute headways in the tunnel, 12 minutes to debark, then to the tail track, then 15 minutes to embark, minus time to get from the tail to the platform.

OTOH, there is a dedicated mezzanine the full width of the train box, so with one island is a dedicated arrival island and one island is a dedicated departure island, and boarding an empty train after most passengers have been marshalled into the correct bunch in the mezzanine level seems like it could be made into a fairly quick proposition.

Still, there seems to be "mission creep" with some commentators at the California HSR blog in terms of shorter and shorter station dwells being "reasonable", including biased spin being tossed in by the TBT engineer, so maximum allowed platform dwells for the French, Spanish and German HSR services would be useful real world information.

(And, yes, Japanese terminal platform dwells seem likely to be Sugoi! ... amazing ... but if the system has to run to Japanese human tolerances to avoid delays, I don't think that will happen in California.)

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Mon Mar 23rd, 2009 at 01:44:39 PM EST
[ Parent ]

Re: Platforms (none / 1)

maximum allowed platform dwells for the French, Spanish and German HSR services would be useful real world information.

Unfortunately, I don't have those data (if they are fixed at all -- I don't think they are in Germany at least), but I will make some notes.

First, it may be that East Asian high-speed is really a better comparison than Europe. CHSR traffic will be shuttle-like: keeping to dedicated lines with relatively short total travel times. However, In Europe, longer high-speed train runs continuing on conventional track are more typical, especially in Germany. (The exception is Spain, but there, station capacity is adjusted to an expected massive future growth, so currently they aren't pressed.)

So, in Europe, turnaround times may be lengthened by a buffer for delays, and shortened by a service concept foreseeing most of the work (like filling up tanks) during the night, when there is time anyway. As a rule of the thumb, 1-1.5 hours would be normal for stops including cleaning/checking. Some numbers:

Paris Gare de Lyon:

The surface station has 22 tracks. TGVs depart at a maximum 9 tph, an additional 6 non-TGV trains also depart in the peak hour. I couldn't track down French circulation plans, but extrapolating for a maximum capacity from the minimum 4-minute headways, I get 60-minute turnaround times.
AVE:

Barcelona Sants, Sevilla Estación de Santa Justa both have 6 normal-gauge tracks for high-speed trains, but only a maximum 3 tph; Málaga's Estación María Zambrano even 5 tracks for a max. 3 tph -- though, not evenly distributed. There are 10 minute headways, so one can assume a capacity of 6 tph with, again, 60 min turnaround times.
Germany:

The shortest turnaround I found with a brief search was 53 min, for turnarounds including a visit to the maintenance yard: 109 min(!). More relevant for CHSR is the example of the onetime Metropolitan, which ran a short tight schedule between Cologne and Hamburg: turnaround times were down to 34 minutes.

As for East Asia: in Tokyo, both JR Central and JR East operate up to 11 tph, but the former from 4 tracks while the latter from 6. Taipei Main Station has 4 tracks for THSR trains, with a maximum 5tph right now.

Now, it is one thing whether Japanese precision can be copied in SoCal, another is passenger discipline, yet another the size and efficiency of maintenance crews. So I don't think 12tph is possible in the TBT on four platforms (e.g. 20 minute turnarounds).

By the way, is the operation of the 3 access tracks in the tunnel with one track strictly for the total incoming traffic, and two for departures, an explicit design feature, or your interpretation? Because I don't like that. Three tracks with a proper train signalling in bi-diretional operation might be better, but unless Caltrain is electrified and gets modern EMUs, I would prefer to not run 'em on the same track at all.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Tue Mar 24th, 2009 at 07:01:25 PM EST
[ Parent ]

Re: Platforms (none / 0)

First, yes, this is part of Caltrain getting modernized and getting all modern EMU's.

As far as bi-directional track, its a mile plus of tunnel with two very tight turns, and transit time to clear the track is likely to be fairly long. With each tunnel track directly connecting to one island (pair of platform tracks), clearing a pair of platform tracks then filling them would be an even longer period the platform is idle.

With the system pressed for platform dwell time, the freedom of completely parallel movements for each island comes at a substantial reduction in total train capacity.

Now, without a fracking through track looping back to the present terminal (clenches fist and shakes it in a vaguely western direction at the TBT authority), dedicated two-way track has substantial higher throughput capacity than bi-directional track.

The penalty, of course, is that there is no longer completely parallel movements per island.

However, with a central access track and an egress track on each side, then it can be set up to allow parallel HSR access and Caltrain egress, and parallel Caltrain access and HSR egress.

That means that if Caltrain and HSR services enter in alternation, there is an open slot for HSR egress before each HSR access, and an open slot for Caltrain egress before each HSR access.

It could equally well be two access and a central egress, but since the total station dwell capacity limit is at the TBT trainbox side of the tunnel, if the access and egress capacities are to be unbalanced, the larger capacity should be allocated to egress.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Tue Mar 24th, 2009 at 08:51:56 PM EST
[ Parent ]

Re: Platforms (4.00 / 2)

two very tight turns

How tight?

With each tunnel track directly connecting to one island (pair of platform tracks), clearing a pair of platform tracks then filling them would be an even longer period the platform is idle.

From the arrangement described in your diary, at least the Caltrain platforms can be reached from two of the tunnel tracks. Making just one of the tunnel tracks bi-directional, e.g. the Caltrain departure track, would already be an improvement. It would add the possibility of a Caltrain and a CHSR train arriving in parallel, which, due to eventual delays, is more important than the possibility of two departures in parallel.

E.g., in addition to these possibilities:

...now you would gain this one:

Even better would be another connection between the two outer tracks, so that a Caltrain departure opposite a parallel Caltrain+CHSR arrival is possible.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Wed Mar 25th, 2009 at 04:40:44 AM EST
[ Parent ]

Re: Platforms (none / 0)

How tight?

I don't know ... I have seen claims they are too tight to be workable. Other than vague happy talk, all I can find is the fuzzy diagram from a 2003 document that was part of the Environmental Impact Report process.

When I say in the post that I don't know if its physically possible ... that's part of it. Swinging the central platform tracks so they come in #2 and #3 from the outside, and the tail track so they go out #1 and #2 from the outside, buys some straightening. Probably not enough, though.

When I was sketching out an operations table, I included one empty slot for four full slots on the access track for delays.

On the CAHSR blog, Brandon in San Diego pointed out that Prop 1A requires 5 minute headways on the HSR network, so on the operation model above, with alternation between HSR and Caltrain built in, an argument can be made that 2 1/2 minute headways would be required by the funding legislation. Tighter headways does not increase platform capacity, so if they can arrive at 2 1/2 minute headways, that could be one open slot for each pair of inbound services.

Its parallel arrival HSR / departure Caltrain and parallel arrival Caltrain / departure HSR that is the point of having an egress track on either side of the access track ... eliminating that crossover between access and egress tracks at grade (or at least, putting it off to the mouth of the tunnel, when its a "half-dive" ... cheaper because the tracks have to dive into the tunnel in any event) ... is what that accomplishes.

As for bidirectional operations on the Caltrain egress track, if the Caltrain egress track is taken down first, to dive under the common access track to the tunnel, it can be a central branch, switched to both sides of the two way track out of the current terminal at 4th, which is about 2km away.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Wed Mar 25th, 2009 at 11:42:03 AM EST
[ Parent ]

Re: Platforms (none / 0)

Even better would be another connection between the two outer tracks, so that a Caltrain departure opposite a parallel Caltrain+CHSR arrival is possible.

From the diary:

The only player that strikes me as having the opportunity to say, "wait a minute, here's a fix that won't cost all that much to implement" is Caltrain. But ... under the solution above, they are giving up a 900 ft. platform, connected to the tail tracks, for what could end up being a 800 ft. platform, with only one connection to the tail track, and that connection only available when the closest HSR platform track is empty.

So, yes, the above, which would make it operationally feasible to squeeze 8tph into four terminal platforms, and which may or may not be physically feasible, does knock on to make things even worse for Caltrain. Efforts to squeeze extra capacity out of the same infrastructure tend to generate bad trade-offs like that.

If there is going to be three tracks, the ideal would be an access track on the one side, an egress track on the other, a bi-directional track in the middle with switches at several points along the tunnel, and an adequate 3:6 fan out including as many dives as necessary to avoid blocking movements.

But the TBT is a property redevelopment project using a transit project as its hook, with the location itself the wrong place for a central rail terminus, and while cut and cover tunneling for the station throat can be useful as an excuse to take over and redevelop certain sites, extra money for an adequate platform access or extra tunneling for dives (and its basically tunneling in mud, so it'll be fairly expensive) ... they are kind of "only if someone else pays for that part".

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Wed Mar 25th, 2009 at 11:56:43 AM EST
[ Parent ]

Re: Platforms (none / 1)

Málaga's Estación María Zambrano even 5 tracks for a max. 3 tph

Typo. Should be: 2 tph.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Wed Mar 25th, 2009 at 04:07:15 AM EST
[ Parent ]

Re: Platforms (none / 0)

Richard Mlyrnik says on the Caltrain HSR Compatibility Blog:

Start with "pretty much any ICE or EC stopping at Leipzig Hauptbahnhof."
There are thousands of other examples.
eg ICE 692: ... -- Stuttgart 08:47 08:51 -- Frankfurt(Main) 10:08 10:13 -- ...

Is there any way to find the turn-around times for HSR trains at Leipzig Hauptbahnof?

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Mon Mar 30th, 2009 at 11:20:45 PM EST
[ Parent ]

Re: Platforms (none / 1)

Does "turn-around" refer to the train changing direction, or to emptying the train, cleaning it, and starting a new route. If the former, HSR can be turned very quickly indeed. I suspect the 30+ minutes refer to the latter, and you'll have a hard time finding these figures by simply studying the schedules.

by gk (gk (gk quattro due due sette @gmail.com)) on Thu Apr 16th, 2009 at 04:44:30 AM EST
[ Parent ]

Yes, it does appear that when ... (none / 0)

... CHSRA is saying 40 minutes, they are talking about route terminus operations.

The most important route terminus operations for building ridership, of course, are the infrequent ones ... the operations to prevent a train swap from creating a service delay, and to prevent one service delay from cascading to multiple service delays.

But if they are through services through a terminal, with the route terminus located somewhere else, then that time buffer is also located somewhere else.

The restock, full clean, high frequency safety checks, etc., that are scheduled as the normal terminus operations are an efficient way to use the time, but for corridor trains that are not operating around the clock, many of them do not have to be done when they are, but are more spreading the work around and not letting the time buffers built into the system go to waste.

More on this in Part 3.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Thu Apr 16th, 2009 at 01:40:18 PM EST
[ Parent ]

Re: Platforms (none / 0)

As gk said. Frankfurt Hbf is another terminal station where almost all long-distance trains (be them ICE or loco-pulled IC/EC) change direction, but don't end their run, and thus the time is short. Also true for most trains in Stuttgart Hbf, andmany in Munich Hbf.

To complicate matters, in Germany, many long-distance trains run in circuitous routes -- e.g. a train may run a big half-circle from Berlin through Dortmund Frankfurt, Stuttgart to Munich, then go North through Nuremburg to Hamburg; or alternatively through Leipzig back to Berlin... and in such a case, the "terminal station" is a matter of choice.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Fri Apr 17th, 2009 at 11:26:38 AM EST
[ Parent ]

Re: Platforms (none / 0)

Uhh, and sorry for a very belated reply, didn't catch it.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Fri Apr 17th, 2009 at 11:27:15 AM EST
[ Parent ]

Re: Platforms (none / 1)

That was the discussion on the Caltrain HSR compatibility blog ... if the TBT is used as a through-service terminal rather than as a route terminus, at least when trains are turning around, its not the platforms that are a bottleneck, but rather the requirement to offer 5 minute headways to the HSR.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Fri Apr 17th, 2009 at 07:06:18 PM EST
[ Parent ]

Re: Platforms (none / 1)

But, NOT using it as a terminal station is pretty stupid, aint' it.

On one hand, from the passengers' point of view, it will be a terminal station -- meaning that all passengers of the arriving train will get off, and all passengers on the departing train will board there. You can't use the 6 minute turns in Frankfurt as example for that -- 10-15 minutes in Vienna Westbahnhof is more like it.

Then, you'd have to service trains in LA after a full turn (that would be up to 7 hours 20 minutes without servicing, with runs in 213-minute train pattern #3 both ways), or devise an operation plan in which runs from LA to SF are always followed by a run from SF to Merced, where there would be time for servicing.

All in all, I have a very bad feeling about this TBT project. The seeds of several future problems will be planted, even with the improvements you sketch in the second and third diaries.

_{*Lunatic*, n.

One whose delusions are out of fashion.}

by DoDo on Sat Apr 18th, 2009 at 04:57:26 AM EST
[ Parent ]

10-15 minute turns are plenty short enough ... (none / 1)

... four platforms and 15 minute turns permits 12tph with a 5 minute time buffer for each turn.

The TBT project will, of course, be studied in future years as an vestige of the Kamikaze Century, when the location of bus ramps onto a road bridge could determine the location of what was supposed to be the main rail hub of a city like San Francisco ... because the rail hub part of it was tacked on as something that sounded good, with the plan of getting trains in and out left for later.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Sat Apr 18th, 2009 at 07:13:12 AM EST
[ Parent ]

Also, note that platform terminus ... (none / 0)

... capacity is much less of an issue at the Southern end, because as the system builds out, it becomes a "Y", with an Anaheim terminus and a San Diego terminus (well, its an "X" including Sacramento, but with the bulk of northbound routes heading to the San Jose / San Francisco side). Anaheim platforms are at grade, and they are building the platforms to the CHSRA request, while if the San Diego terminus is at the Airport, that will be able to act as a through platform when needed to avoid getting bottlenecked.

I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.

by BruceMcF (agila61 at netscape dot net) on Sat Apr 18th, 2009 at 01:57:35 PM EST
[ Parent ]

A Train Station Grows At Transbay ... (pt. 1) | 30 comments (30 topical, 0 editorial, 0 hidden)

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A Train Station Grows At Transbay ... (pt. 1)

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