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Old May 7th, 2010, 12:59 PM   #1681
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2020. But you know they revise the mid-long term plans all the time.
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Old May 7th, 2010, 02:53 PM   #1682
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Amazing map!
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Old May 8th, 2010, 12:01 AM   #1683
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Quote:
Originally Posted by Abhishek901 View Post
Yeah. 40 trains per hour is achievable with today's ATO (automatic train operations) technology and I think many lines of Shanghai have ATO. But the reason for low frequency is the shortage of rolling stock as somebody suggested. So I think this is a temporary problem and will get solved with arrival of new rolling stock.
With safety doors on platforms 40 trains per hour is impossible...
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Old May 8th, 2010, 01:50 AM   #1684
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Why do safety doors slow frequency?
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Old May 10th, 2010, 11:26 AM   #1685
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I don't get that, either. It would also contradict the use of PSD's on some of the busiest Paris Metro lines (1 and 14).

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Old May 10th, 2010, 07:45 PM   #1686
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Quote:
Originally Posted by pearl_river View Post
http://www.nytimes.com/2010/04/30/wo...0shanghai.html

Shanghai’s infrastructure has been upgraded over the past several years with new roads, bridges, tunnels and airport terminals. Three weeks ago, a new 18.6-mile subway line opened in the western part of the city — the 11th since the city’s subway system first opened in 1995.

“After we won the right to host the Expo in 2002, we planned to construct 970 kilometers of underground track in the future and at least 400 kilometers by 2020,” said Zheng Shiling, who teaches at Tongji University in Shanghai. “But today, we already have 410 kilometers of underground track. We’ve fulfilled our plan 10 years early.”
Today is an historical day! After 147 years London tube lost its word leadership.
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Old May 10th, 2010, 07:58 PM   #1687
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Today is an historical day! After 147 years London tube lost its word leadership.
But only in the length. In ridership, density and reliability it lost leadership years and years ago
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Old May 10th, 2010, 11:16 PM   #1688
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Not to mention that these 410 km have been built since 1995! 15 years only.

By the way, I wonder if London has really these 408 or whatever kms as we know many tracks are shared.
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Old May 10th, 2010, 11:19 PM   #1689
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Quote:
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Why do safety doors slow frequency?
Frequency, maybe not, but the whole line capacity it sure does. These doors slow down quite much the total time of getting off-getting on, the train has to stay longer, thus reducing the line's commercial speed.

I am sorry to have told it like that above, it's not the frequency, but the total capacity of a line and especially its average commercial speed which are touched...
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Old May 11th, 2010, 12:16 AM   #1690
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Quote:
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But only in the length. In ridership, density and reliability it lost leadership years and years ago
Many people in Shanghai are also aware of differences in ticketing and station locations though.
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Old May 11th, 2010, 01:56 AM   #1691
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Quote:
Originally Posted by _Night City Dream_ View Post
Frequency, maybe not, but the whole line capacity it sure does. These doors slow down quite much the total time of getting off-getting on, the train has to stay longer, thus reducing the line's commercial speed.

I am sorry to have told it like that above, it's not the frequency, but the total capacity of a line and especially its average commercial speed which are touched...
In Shanghai the platform doors open and close at the same time as the train doors. I don't see how they affect dwell time at all.
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Old May 11th, 2010, 03:16 AM   #1692
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Typically, platform doors do add dwell time. There is usually about four to five seconds after the train has come to a complete stop before the platform doors and train doors open (and likewise, there is usually a similar wait before the train departs).

I would be dubious of achieving 40 tph on Shanghai's system, because the passenger movements are generally too high to do so. Your overall frequency is determined by the busiest station (i.e., longest dwell time) on the line. Probably, 30 to 32 tph is the max.

Last edited by quashlo; May 11th, 2010 at 03:21 AM.
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Old May 12th, 2010, 11:08 AM   #1693
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On the new lines, the drivers sometimes have to back up to align the car with the platform doors.
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Old May 12th, 2010, 12:12 PM   #1694
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Quote:
Originally Posted by Severiano View Post
On the new lines, the drivers sometimes have to back up to align the car with the platform doors.
That is because the new lines are still operated in manual mode. The automatic mode still needs some time for tuning and testing.
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Old May 15th, 2010, 06:37 PM   #1695
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Quote:
Originally Posted by _Night City Dream_ View Post
By the way, I wonder if London has really these 408 or whatever kms as we know many tracks are shared.
London has now 400 km after it shed 8 km East London line to London Overground. This length counts shared lines as one. Taking shared lines as separate one, it is around 450 km.

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In Shanghai the platform doors open and close at the same time as the train doors. I don't see how they affect dwell time at all.
That's what I was thinking of.

Quote:
Originally Posted by quashlo View Post
Typically, platform doors do add dwell time. There is usually about four to five seconds after the train has come to a complete stop before the platform doors and train doors open (and likewise, there is usually a similar wait before the train departs).
Yes, there is a lag between stopping of train and opening of doors but there is no lag between opening of train doors and platform doors. So theoretically it should not add to dwell time.

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Originally Posted by quashlo View Post
I would be dubious of achieving 40 tph on Shanghai's system, because the passenger movements are generally too high to do so. Your overall frequency is determined by the busiest station (i.e., longest dwell time) on the line. Probably, 30 to 32 tph is the max.
40 TPH has been achieved in other systems also and if they are going at 40 TPH, then surely means that those systems too would be heavily used.

Regarding stopping time at the busiest station, if the trains stops for 30 sec at the busiest stations, and it takes 10 sec for the time lags between opening and closing of doors, etc., then also it leaves a gap of 50 sec (90-40) between departure of one train and arrival of other. Modern signalling systems are capable of handling that frequencies. However if stoppage time increases at major stations, then it is a big concern.
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Old May 16th, 2010, 01:43 AM   #1696
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Quote:
Originally Posted by Abhishek901 View Post
Yes, there is a lag between stopping of train and opening of doors but there is no lag between opening of train doors and platform doors. So theoretically it should not add to dwell time.
I don't understand your logic here... Also remember that computers aren't perfect, and the operator frequently needs to realign the train with the platform doors or barriers, which easily adds another ten seconds or more. You also need to design in some slack, as no system is perfect.

In fact, I just saw one two days ago at Hongqiao Terminal 2 Station spend thirty seconds plus trying to realign twice (once going in reverse) with the platform doors. In the end, the operator opened the doors, but the train doors still weren't perfectly aligned.

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Originally Posted by Abhishek901 View Post
40 TPH has been achieved in other systems also and if they are going at 40 TPH, then surely means that those systems too would be heavily used.
Really? Take Paris, for example. The rolling stock is quite small, and the interior layout limits standing passengers, so overall, the "passenger load" per door is actually smaller. Just looking at the surface, one might say, "Well if Paris can do it, then why can't Shanghai (or xx)?" but you can't really compare the two.
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Old May 16th, 2010, 02:21 AM   #1697
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abishek was alluding to platform doors in general, and not one specific example of malfunctioning doors due to teething difficulties. similarly, you could have stated that computer controlled trains are worse than old fashioned manual controls because computers can break down. yet do computer controls make the subway any slower on average?

if the various transit systems were to be built from scratch, and had generous budgets, i'd bet they'd all choose platform doors. on the systems i've used, the platform doors opened and closed within a split second of the train's doors, not to mention all their other advantages.

then there's the 'spanish' solution, with separate platforms for boarding and exiting the trains. there, the exiting doors open before the entrance doors. yet at the same time, the process of both entry and exit are so streamlined, the total dwell time at the station is still lower than for orthodox single platform stations.
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Old May 16th, 2010, 03:29 AM   #1698
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abishek was alluding to platform doors in general, and not one specific example of malfunctioning doors due to teething difficulties.
Manual realignment of the train is not uncommon in ATO systems, regardless of whether there are platform doors / gates or not. It's just that realignment becomes an absolute necessity from a safety standpoint when you go with platform doors / gates.

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similarly, you could have stated that computer controlled trains are worse than old fashioned manual controls because computers can break down. yet do computer controls make the subway any slower on average?
What are you rambling on about? I am not making an argument for computer vs. human... I am only disputing the claim that 40 tph is achievable on Shanghai Metro with the current setup.

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if the various transit systems were to be built from scratch, and had generous budgets, i'd bet they'd all choose platform doors. on the systems i've used, the platform doors opened and closed within a split second of the train's doors, not to mention all their other advantages.
Are you reading what I posted? Probably not...
You always get hyper-defensive whenever anyone says anything about Shanghai or China in general. Just sit back and take a chill pill. :ohno

I am not arguing about time lag between opening of train doors and opening of platform doors. I am talking about time lag between train coming to complete stop and train / platform doors opening.

I am also not arguing against platform doors. Only showing that they do increase dwell time.

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Originally Posted by particlez View Post
then there's the 'spanish' solution, with separate platforms for boarding and exiting the trains. there, the exiting doors open before the entrance doors. yet at the same time, the process of both entry and exit are so streamlined, the total dwell time at the station is still lower than for orthodox single platform stations.
And your point is...? What does this have to do with Shanghai?
Or are you just rambling on because you want to sound important?
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Old May 16th, 2010, 03:47 AM   #1699
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^you know,

you stated that the installation of doors would lead to a slowdown in service intervals. from the systems i have seen, hong kong, guangzhou, singapore, and barcelona, there has been no waste of time as the doors have opened almost simultaneously. the trains always stopped on cue, and there was no backing up. and this was over hundreds of subway trips. a long long time ago, i came across a civil engineering report from a coworker that had the same conclusion. your assertion that platform screen doors would necessitate lower frequencies is not borne out in actuality.

then there are the advantages of PSD, allowing more people to safely wait on the platform, within closer distance to the actual track itself. but for the purposes of this argument, they're ignored because those doors are supposedly so slow and unreliable based on your one experience.

sadly i recognize your name from various SSP (and i have never posted there) threads, getting all po'ed over some other minutiae.

now you could continue to say that PSDs will lower the frequencies of trains;

but judging from the quality of your arguments and your demeanor, it's safe to say that you're arguing to blindly reinforce your initial assertion, or you have some beef against whatever locale involved.
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Old May 16th, 2010, 09:18 AM   #1700
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Quote:
Originally Posted by particlez View Post
then there's the 'spanish' solution, with separate platforms for boarding and exiting the trains. there, the exiting doors open before the entrance doors. yet at the same time, the process of both entry and exit are so streamlined, the total dwell time at the station is still lower than for orthodox single platform stations.
This solution cannot be implemented in already built station. You will need 1 big island platform (for boarding on both up and down trains) and 2 side platforms (for alighting) for this purpose. It would be very difficult to expand operational stations. Also it would be costly to build wider stations for this purpose.

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Originally Posted by quashlo View Post
Manual realignment of the train is not uncommon in ATO systems, regardless of whether there are platform doors / gates or not. It's just that realignment becomes an absolute necessity from a safety standpoint when you go with platform doors / gates.
I have personal experience of metro of only my city, so I cannot comment about others but here I can surely say that lines with ATO perform better than lines without ATO. I have never seen an automatic train re-aligning itself but I have seen mis-aligning in manual trains a few times.

ATO also increase the average speed of the trains because in manual trains, the driver has to slow down the train much before entering the station because he would not want to jump the stop line. He always tries for a slower halt for manually matching the doors/stop line. This wastes some time. But in ATO, trains already know when to start braking and how much braking is needed, so they enter the stations at high speed and brake much faster than manually operated trains. Since the train spends less time in the station for slowing and stopping, the actual dwell time reduces (I am counting both stopping time and braking time in the station).

And to make this property of ATO trains successful, PSDs help a lot as the trains can fearless enter the crowded stations at high speed. Without PSDs, they might need to slow down much before the station to avoid any casualty from a person falling on the tracks. So I believe that PSDs actually help in increasing frequency

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I am only disputing the claim that 40 tph is achievable on Shanghai Metro with the current setup.
What kind of current set up
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