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Post by stapler on Jun 22, 2015 10:58:30 GMT
The TfL website currently boasts of the following capacity increases:
Meeting London's growing demand
London's population is set to increase from 8.4 million today to around 10 million by 2030. The new modern signalling systems and new trains we're introducing will increase capacity to help us meet this challenge.
Bakerloo line:
25% more capacity (the equivalent of up to 8,000 customers per hour)
Central line:
25% more capacity (the equivalent of up to 12,000 customers per hour)
Piccadilly line:
60% more capacity (the equivalent of up to 19,000 customers per hour)
Waterloo & City line:
50% more capacity (the equivalent of up to 9,000 customers per hour)
The Piccadilly line currently serves 210 million customers a year and demand is expected to grow 20% by 2020. The Piccadilly line has therefore been prioritised as the first of the four lines to benefit from the new trains and signalling system.
I can see that marginal increases could be achieved eg. by signalling upgrades, but I can't see how the Central Line (eg) could deliver 25% by that means. Longer trains are out, so how can these figures be realistic? Or perhaps the increases are merely to bring off peak hours into peak frequencies?
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Post by snoggle on Jun 22, 2015 12:23:24 GMT
Surely part of the assumed increase is delivered by the proposed new rolling stock design which allow more people to be squashed inside each train? It's not all down to signalling capacity but that will be part of the scheme. It looks to me that LU's new objective is 36 tph in the peaks if infrastructure can cope with it. That will also be a factor in driving up the capacity increases being predicted.
I'm more concerned about whether stations can cope with ever increasing volumes of people being decanted from trains or trying to board them.
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Post by Chris M on Jun 22, 2015 12:33:18 GMT
That is a good point about station capacity.
In some cases, there is little that TfL can do without a major rebuild of the station - Camden Town comes immediately to mind. Sometimes a key issue is that pedestrians exit onto a narrow pavement that becomes blocked very easily leading to congestion down into the station - exit 2 at Leicester Square, particularly in wet weather, is the one I'm most familiar with.
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Post by stapler on Jun 22, 2015 12:48:39 GMT
So the "capacity increase" may just be further cramming in, doubtless in the walkthroughs between cars. Seeing the behaviour of these on sharp curves (eg Liv St-Bank, Central) will be interesting.....
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Post by snoggle on Jun 25, 2015 16:31:45 GMT
So the "capacity increase" may just be further cramming in, doubtless in the walkthroughs between cars. Seeing the behaviour of these on sharp curves (eg Liv St-Bank, Central) will be interesting..... Not sure it's fair to say "just cramming in" but inevitably crowding will worsen even if trains are designed to maximise standee space. If we look at the evidence of recent upgrades then the aim has been to improve line speeds, improve run in / run out times, do the best with dwell times and manage turnround times at termini. If we end up with fully automatic trains then turnrounds could be extremely short in future as on the DLR. It's probably clear that 36 tph is all that can be achieved on the very busiest lines. We may also end up with platform edge doors to allow separation of fast moving trains from overcrowded platforms. In short it has to be a package of measures to achieve the largest possible capacity increase. |
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Post by stapler on Jun 25, 2015 16:57:14 GMT
As far as the Central is concerned,of which I have most recent experience, that means 18tph on each of the eastern branches or a train approx every 3 minutes, still too few EG) to deal effectively with the situation between Leytonstone and Stratford, though Crossrail may help west thereof.
More Loughton-Woodford reversers will be needed to relieve gross overcrowding at inner stations.
Are platform doors practical on open-air platforms?
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Post by Chris M on Jun 25, 2015 17:50:17 GMT
Platform doors have the same advantages and disadvantages regarding platform and PTI safety whether they are indoors or outdoors. Other factors, e.g. airflow management are obviously different.
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Post by will on Jun 25, 2015 18:14:20 GMT
Would the capacity increases on the central line not be achieved by running 36 tph for 3 hours in each peak period rather than just for half an hour in the morning peak?
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Post by Deleted on Jun 25, 2015 18:57:54 GMT
More Loughton-Woodford reversers will be needed to relieve gross overcrowding at inner stations. When you say 'Woodford reversers', d'you mean Woodford via Hainault's? I don't think they're gonna wanna do that. If you mean Woodford via Snaresbrook, that's - that's not a good idea. Mind you, who knows what remodelling might take place at Woodford with this round of resignalling. Maybe reversing at Woodford could become a possibility in future. Although I think extending trips, rather than shortening them, is the name of the game these days. Would the capacity increases on the central line not be achieved by running 36 tph for 3 hours in each peak period rather than just for half an hour in the morning peak? Indeed currently the dizzying heights of 34 tph is the maximum. |
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Post by superteacher on Jun 25, 2015 18:58:12 GMT
Would the capacity increases on the central line not be achieved by running 36 tph for 3 hours in each peak period rather than just for half an hour in the morning peak? The Central line's max frequency is currently 34tph. I'm not sure that 36tph is possible with the current infrastructure, |
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Post by Deleted on Jun 25, 2015 18:59:08 GMT
Would the capacity increases on the central line not be achieved by running 36 tph for 3 hours in each peak period rather than just for half an hour in the morning peak? The Central line's max frequency is currently 34tph. I'm not sure that 36tph is possible with the current infrastructure, It's not possible with the current fleet I can tell you that for nowt!  |
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Post by will on Jun 25, 2015 19:57:57 GMT
if the Central had a larger fleet of trains would 36tph not be possible? How many trains is the Central Line to receive under the new Tube for London project 100?
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Post by stapler on Jun 25, 2015 20:00:25 GMT
More Loughton-Woodford reversers
I mean, eastbound trains reversing at Loughton or Woodford to provide an emptier westbound train with more capacity at stations west thereof
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Post by Deleted on Jun 25, 2015 20:39:42 GMT
Reversing eastbound trains at Woodford currently is not a good idea.
The first problem is that trains must go via 21 road, which is usually full of, or awaiting the imminent arrival of, the Hainault train.
The second problem is that trains must go via 21 road. For trains going to the bay platform, this adds 1¾ minutes eastbound and ¾ minutes westbound. For trains reversing off platform 3 this wouldn't add anything to the eastbound trip, but would add to the westbound trip. Obviously reversing east to west off platform 3 isn't an option anyway because it would delay the eastbound main unacceptably and would create chaos and confusion with people having to faff around changing platforms.
The third problem is that trains must go via 21 road, which is a multiply conflicting move with the main line.
Conceivably a remodelling of the layout at Woodford - perhaps back to how it used to be before the remodelling in the 90s - along with resignalling could relieve some of these problems a bit. But not by very much. There would still be multiple conflicts and the necessary low speeds and increased journey times further increase the effect on the main line. Add to this the fact that the Woodford via Hainaults already impose similar problems and it would absolutely decimate the service on the main line.
The fourth problem applies currently and will continue to apply whatever upgrades are carried out. There is too much demand east of Woodford. Trips are being extended network wide, not shortened. There is no way it would make sense to curtail trips to Woodford.
Loughton is a bit more conceivable, it's actually a very flexible location. However, I'm not sure you can put enough trains through it in both directions and add even more reversers.
I think what you're much much more likely to see is the larger fleet enabling more trains to run the full length and keep up the frequency through the centre. Neither Epping - nor even Hainault - are exactly overstretched at this point, even with just two platforms at Epping. Same goes for Ealing Broadway I'd say - and probably West Ruislip too. Anyway, the number of trains you can put through the pipe is fixed and if the idea is to shorten trips so that trains arrive at places like Stratford emptier (having served fewer stations and therefore not had time to fill up), I think you're shooting yourself in the foot a lot. Taking trains away from stations east of Woodford will mean that trains serving those stations will be much busier. Dwell times will be adversely affected and they will arrive at Woodford and stations west of it busy. Meaning that the people there will have more trouble getting on. And then more of them will have to pile onto the "emptier" Woodford reversers.
Now, add to this picture the effect on capacity of points 1-3 above and...
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Post by stapler on Jun 25, 2015 20:56:15 GMT
Agree Woodford is an operating nightmare. But not so Loughton. The situation at present is effectively that the fare structure (epping, Theydon in Zone 6 cf Brentwood-Broxbourne- Shenfield with much higher farees)) is subsidising car commuters to drive long distances and clog up those two places, and jam-pack the trains so people who live further down the line can't get on!
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Post by Deleted on Jun 25, 2015 21:06:52 GMT
I'm sure superteacher will agree with me that the obvious solution is actually to turn more trains at Grange Hill (via Woodford) (Tongue in cheek) |
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Post by stapler on Jun 25, 2015 21:09:47 GMT
No, tongue out!
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Post by Deleted on Jun 25, 2015 21:18:57 GMT
Those who have no voice are ignored; that's why I keep my tongue in my cheek |
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Post by superteacher on Jun 25, 2015 21:33:21 GMT
I'm assuming that the 100 kph running trial was not successful?
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Post by stapler on Jun 26, 2015 7:54:51 GMT
It may just be a misimpression, but I have been aware of higher speeds on the Central Line recently at weekends, and "waiting for the clock" at stations more than usual
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