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Old January 20th, 2009, 01:48 PM   #3341
Tubeman
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Quote:
Originally Posted by Jang0 View Post
Tubeman,

In your view, what are the main bottlenecks on the existing system (by principle, as opposed to examples - although examples wouldn't go amiss).

Some of them I imagine would be:

1) Terminating stations with only 2 platforms connected by a scissor on incoming side. This reduces capacity because of conflicting train paths and limited time that each train can spend at the terminus.

2) Infrequent fixed-block signalling (JLE, for example)

3) Poorly designed stations where passenger flow inhibits short dwell-times

4) Non-grade separated junctions

And also, if you were designing a new tube line, how would you design it so that it had absolutely top capacity shifting massive numbers of people per hour?
You've pretty much hit the nail on the head with those 4.

The only quibble is for #1... having the scissors on the incoming side is actually preferable as if trains had to proceed beyond the platforms onto over-run sidings for the crossover, they would each need to be detrained before the move (i.e. closed up car by car and assurance that no passengers are on board). This came about after a fataility in Liverpool Street sidings a few years back. If the detrainment was not necessary, then you're right having the crossover beyond the terminating platforms is preferable as it removes conflicting train movements coming into the platforms (it's also better for customers, as all departures are from the same platform).

2) Yes, definitely... the JLE signalling was a balls-up as the desired ATO didn't work so traditional Westinghouse trainstop / tripcock ATP was installed, but with quite sparse signalling as it was intended to be temporary. The southern half of the Circle also used to have far denser signalling with a lot of time-controlled sections to allow higher tph, but this was all ripped out when demand fell and there was no longer a need (to save on maintenance costs)... Pity, but academic as it'll be ATO soon enough hopefully.

3) Also a real issue: busy platforms where access / egress is at one end so everyone crowds around a couple of cars and don't spread out... If a few of the busiest stations on a line have access at a similar point, this compounds the problem (the Bakerloo SB is bad for this... often the first 5 cars are sardine packed with seats to spare in the last 2 cars).

4) A no-brainer!

My 'ideal' design has the following features:

Terminal loops, including some mid-line for service recovery (similar to the Kennington Loop, but different function).

All doors on the same side: If you picture a line with island platforms throughout and terminal loops, the platforms will always be on the same side of the train.... half the number of doors, half the number of door defects, half the maintenance costs.

Overlapping door leaves: on all current stocks no more than 50% of the side of each car can 'open' at stations as for every metre of door there must be a metre of car body for it to slide onto / into. My idea is that door leaves, when open, overlap each other... this means that instead approximately 2/3 of the 'doors' side of my fantasy stock could open at each station.

Minimise seating

ATO

PEDs

Totally unstaffed trains controlled from a control room: Emergency walkway alongside the trains in the tunnels, direct Public Address from the control room into each car and the tunnels to organise an evacuation. Control room operatives despatch trains from platforms via CCTV... With the added safety of PEDs a handful of Control room staff could control the movements of multiple trains at once.
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Old January 20th, 2009, 02:04 PM   #3342
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Originally Posted by bigbossman View Post
based on the question above tubeman....

what limits trains per hour is it track space... breaking or platform capacity...

i say this because i thought... is it possible for a line to run every minute... if at every station it had two platforms for each running line... ie it would alternate which platform it would go into. so basically train A goes into platform 1, train B 1 minute behind arrives at platform 2 as train A is about to leave and train C arrives at platform 1 as train B is about to leave...
That's an interesting idea, although I guess a little unnecessary.

In my opinion there is an ideal maximum tph above which you begin to create more problems than you solve: it's all well and good having 60 tph and therefore never having to wait more than a minute for a train, but if anything goes wrong you end up with a lot of trains stacked up in tunnels very quickly.... It is always risky to have more trains than platforms, as rule of thumb. Personally I think 20-30 tph is ideal, and this can be handled with the traditional one platform per line provided dwell times are managed well.
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Old January 20th, 2009, 02:05 PM   #3343
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What is your source for that? I sincerely hope its just hearsay as that would compound the reduction in seats that is happening anyway. Although I can see why it would make sense from a fleet management point of view
From the District Line Standards Manager, who is instrumental in the S Stock project.
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Old January 20th, 2009, 02:07 PM   #3344
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Originally Posted by Jang0 View Post
Tubeman,

Where could we find up-to-date information on:

1) District track replacements - how much is done now?

2) Jubilee ATO implementation - what is left to do? when will it 'go live'?
I'm not entirely sure where that sort of information is published, even internally. I can have a look.
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Old January 20th, 2009, 02:29 PM   #3345
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tubeman wouldn't doors on one side of a train, limit the ability to use cross platform interchanges??
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Old January 20th, 2009, 03:58 PM   #3346
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Getting Underground News from the London Underground Railway Society is a good way to stay up to date with the minutae though I don't remember stuff about those particular issues.

How about two platforms for each track. One for entry and one for exiting?
Hmm. Good in theory but probably not in practice as people don't follow the rules!
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Old January 20th, 2009, 05:32 PM   #3347
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tubeman wouldn't doors on one side of a train, limit the ability to use cross platform interchanges??
I guess so... But it could be worked around.
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Old January 20th, 2009, 05:47 PM   #3348
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Quote:
Originally Posted by Acemcbuller View Post
Getting Underground News from the London Underground Railway Society is a good way to stay up to date with the minutae though I don't remember stuff about those particular issues.

How about two platforms for each track. One for entry and one for exiting?
Hmm. Good in theory but probably not in practice as people don't follow the rules!
they would if you couldn't actually exit from that platform... ie 1 way escalators on each platform... obviously there would need to be an emergency staircase...
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Old January 21st, 2009, 02:07 AM   #3349
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Does the Bakerloo line have more experienced drivers than other lines?

It seems, whenever I'm on it that that the trains go faster and the doors open quicker.

They seem to come into stations faster too, faster than the Northern/Piccadilly which are the same length...
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Old January 21st, 2009, 10:15 AM   #3350
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Do Bakerloo tube driver also switch on the heaters properly, because picadilly tube drivers dont, like this morning when it was cold and frost
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Old January 21st, 2009, 11:58 AM   #3351
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Quote:
Originally Posted by iampuking View Post
Does the Bakerloo line have more experienced drivers than other lines?

It seems, whenever I'm on it that that the trains go faster and the doors open quicker.

They seem to come into stations faster too, faster than the Northern/Piccadilly which are the same length...
The 72MkIIs have good braking / acceleration and are quite zippy: they're quite light-bodied, the drawback is that the acceleration and braking can be quite jerky (like the C Stock, which are the same generation), which is why newer stocks have much smoother acceleration and braking to prevent customers being tossed about and falling over. The 73s used to be similar, but I think the refurb added a lot of additional weight to each car.

I don't know how it works on the newer stocks, but certainly on a refurbed 'old' stock like the 72MkIIs the door open buttons can be depressed while the train is still moving (<5mph). This means the driver needs to bring the train's speed down to below 5mph, leave the 'Deadman' in 'Hold' (the braking position for platforms), and can then hit the door open buttons while the train is still coming to a halt, meaning they open instantly the train stops.

I think on newer stocks the train must be fully stationary before 'door open' buttons are active, which will add a couple of seconds to the dwell time (that's a guess, purely from my experience of never seeing the doors open on a 92 / 95 / 96 TS with the train still moving).

But yes, the Bakerloo Line has the best drivers and the management team is second to none
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Old January 21st, 2009, 12:01 PM   #3352
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Quote:
Originally Posted by Amuse2000 View Post
Do Bakerloo tube driver also switch on the heaters properly, because picadilly tube drivers dont, like this morning when it was cold and frost
Might be the theormostat issue I mentioned previously?
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Old January 21st, 2009, 03:45 PM   #3353
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Tubeman,

Having trawled through a good 2/3rds of this thread (and it's taken a while to do so!), have you thought about whether it be good to have a FAQ somewhere, as it seems to me that a lot of the same old questions get asked repeatedly!
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Old January 22nd, 2009, 01:56 AM   #3354
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Quote:
Originally Posted by Tubeman View Post
The 72MkIIs have good braking / acceleration and are quite zippy: they're quite light-bodied, the drawback is that the acceleration and braking can be quite jerky (like the C Stock, which are the same generation), which is why newer stocks have much smoother acceleration and braking to prevent customers being tossed about and falling over. The 73s used to be similar, but I think the refurb added a lot of additional weight to each car.

I don't know how it works on the newer stocks, but certainly on a refurbed 'old' stock like the 72MkIIs the door open buttons can be depressed while the train is still moving (<5mph). This means the driver needs to bring the train's speed down to below 5mph, leave the 'Deadman' in 'Hold' (the braking position for platforms), and can then hit the door open buttons while the train is still coming to a halt, meaning they open instantly the train stops.

I think on newer stocks the train must be fully stationary before 'door open' buttons are active, which will add a couple of seconds to the dwell time (that's a guess, purely from my experience of never seeing the doors open on a 92 / 95 / 96 TS with the train still moving).

But yes, the Bakerloo Line has the best drivers and the management team is second to none
Thanks for that. I think the 95TS doors can be opened before the train stops, I've seen it happen a couple of times. They don't ever seem to do it on the 67TS, I would have thought they did, as ATO means train operator's hands are less busy...
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Old January 22nd, 2009, 02:29 PM   #3355
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I had a Victoria line train driver who opened doors before stopping on Tuesday evening. It seems to be done rarely, but on almost all lines.
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Old January 22nd, 2009, 09:46 PM   #3356
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Quote:
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Tubeman,

Having trawled through a good 2/3rds of this thread (and it's taken a while to do so!), have you thought about whether it be good to have a FAQ somewhere, as it seems to me that a lot of the same old questions get asked repeatedly!
Good idea... Any suggestions for questions? Saves me repeating myself!
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Old January 22nd, 2009, 11:49 PM   #3357
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How about these for starters:

1) What do you think of:
Tube
DLR
National Rail
TfL
Ken/Boris

2) What are the current proposals for London's Transport?

3) Why can't we have more tph on the Underground?

4) Why is the tube so unreliable?

5) How does ATO work on Victoria/Central/DLR ?

6) Why is it so expensive to build anything these days?

7) Will the Bakerloo ever be extended to the South?

8) Will Crossrail solve all London's problems?

9) What would your ideal tube line look like, and where would it go?

- I reckon I could answer most of these, but I'm really thinking of the next person that comes along!
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Old January 23rd, 2009, 11:16 AM   #3358
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"For starters" ?? Poor Tubey has been answering every question of ours for over three years! (thanks again)

Maybe I can help out a bit with the (IMHO) easy ones.

3) It would be bloody unreliable. Might be possible with a completely new line without budget cuts, new stock, new signals, well-behaving passengers and so on, but on the current network I reckon 20-30 tph is already a massive challenge.

4) The network is the oldest in the world and has in the past been underfunded.

6) Our standard of living. It could be cheaper but we'd have to bring back the worker class that existed a century ago but nobody wants that.

8) No. London isn't stuck in a time bubble and its needs will continue to change if not outright grow.
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Old January 23rd, 2009, 12:09 PM   #3359
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you missed the point!

These questions are supposed to be for his FAQ, so that he doesn't have to keep answering the same ones over and over again!

Also, by putting more detail in his FAQ, they'll probably be better answers too, because it's unlikely that he would provide that level of detail every time he's asked.
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Old January 23rd, 2009, 12:22 PM   #3360
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Sorry, bit of a late night last night, skipped to the last post and didn't remember the on-going discussion!

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