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Post by saphil on Dec 5, 2014 13:31:07 GMT
On two occasions recently myself and other passengers have had great difficulty boarding at Farringdon (Eastbound) in the morning peak because it takes so long for the people to get off the train that the doors are closing before we can get on. I appeciate that there is a timetable to attempt to keep to but it would be nice to actually pick up the passengers waiting for the train! My perception is that the problem has got worse with the introduction of the S stock, possibly because more people can get on the train (further up the line  than previously. Maybe some slight timetable adjustments are needed to allow for a slightly longer stop at busy stations? Phil |
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North End
Beneath Newington Causeway
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Post by North End on Dec 5, 2014 13:38:54 GMT
On two occasions recently myself and other passengers have had great difficulty boarding at Farringdon (Eastbound) in the morning peak because it takes so long for the people to get off the train that the doors are closing before we can get on. I appeciate that there is a timetable to attempt to keep to but it would be nice to actually pick up the passengers waiting for the train! My perception is that the problem has got worse with the introduction of the S stock, possibly because more people can get on the train (further up the line than previously. Maybe some slight timetable adjustments are needed to allow for a slightly longer stop at busy stations? Phil The problem is that if you include too much dwell time in the timetable then it restricts the number of trains which can be run through the location - in extreme cases this can restrict the throughput for the entire line. However, if you don't include the dwell time in the timetable then trains will likely just dwell anyway, and then run late, so you can't win either way, but obviously passengers boarding and alighting as quickly as possible helps. From a driver's point of view, the driver will attempt to allow everyone to board - but the bigger picture sometimes comes in to play, if the train has a large gap in front then there are likely to be a number of trains close behind, therefore in this situation is can make sense to leave people behind. It's frustrating to those left behind, but if not done the train can accrue 30-60 extra seconds at each successive station, so the problem just gets worse and worse. |
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Post by saphil on Dec 5, 2014 14:22:08 GMT
From a driver's point of view, the driver will attempt to allow everyone to board - but the bigger picture sometimes comes in to play, if the train has a large gap in front then there are likely to be a number of trains close behind, therefore in this situation is can make sense to leave people behind. And then the same thing happens with the next train as there are now even more people trying to get on it! I understand the problem but it's almost like the passengers are regarded as an inconvenience to letting the trains run on time  . I'm not sure anything can be done about it but it's an unfortunate side effect of being able to cram more people into S stock trains. |
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Post by orienteer on Dec 6, 2014 17:15:09 GMT
Since S stock is walk-through, you can try boarding at a different point on the platform. Regular travellers tend to position themselves on the train near the platform exits at their destination, so these are the busiest points.
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class411
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Post by class411 on Dec 6, 2014 17:58:04 GMT
Is this by any chance made worse by a certain type of passenger who cannot be bothered to get up from its seat until the last detraining passenger is stepping out of the door.
I don't know if this happens as much at peak times but it can certainly delay things, as all the entraining passengers who have been politely waiting and think the way is clear have to take a step back to accommodate the numptie who has left it well past the last reasonable moment.
(Obviously, for some, this is sometimes a result of not realising that it is their station, but there are others - you can observe them if you are on the train - who seem to make this a policy.)
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Deleted
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Post by Deleted on Dec 6, 2014 18:08:31 GMT
North End is right. Although it does seem a roundabout way of inferring passengers are an inconvenience, it is a fact that the constraint on service headways at some locations is not signalling or track but dwell times (Canary Wharf and probably Kings Cross C&H are good examples). Plans to increasing the tph on the Jubilee will need to be coupled with careful management of dwell times at Canary Wharf and no doubt in the future the same will be true of some Sub Surface locations too.
One positive effect of new signalling however is that headways are better managed by automatic regulation so the random long gaps that result in heavy loadings should be reduced.
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North End
Beneath Newington Causeway
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Post by North End on Dec 6, 2014 20:29:04 GMT
North End is right. Although it does seem a roundabout way of inferring passengers are an inconvenience, it is a fact that the constraint on service headways at some locations is not signalling or track but dwell times (Canary Wharf and probably Kings Cross C&H are good examples). Plans to increasing the tph on the Jubilee will need to be coupled with careful management of dwell times at Canary Wharf and no doubt in the future the same will be true of some Sub Surface locations too. One positive effect of new signalling however is that headways are better managed by automatic regulation so the random long gaps that result in heavy loadings should be reduced. Hmm, I'm not entirely convinced Seltrac achieves this. It certainly works hard to prevent early running, but I can think of three specific examples of times when very minor out-of-course running has given me massive gaps in front during peak times, with consequential massive loss of time due to long unloading/loading times. Having said that, it goes without saying that the system is only as good as the signaller operating it! |
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class411
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Post by class411 on Dec 7, 2014 8:19:33 GMT
What on earth is "King's Cross C&H"? Assuming it's not just a typo for H&C. |
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Post by superteacher on Dec 7, 2014 10:07:14 GMT
What on earth is "King's Cross C&H"? Assuming it's not just a typo for H&C. Same thing. |
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class411
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Post by class411 on Dec 7, 2014 10:33:34 GMT
What on earth is "King's Cross C&H"? Assuming it's not just a typo for H&C. Same thing. Not really. Except, I suppose in the same way that CBB is the same thing as BBC or E&A is the same thing as A&E. In each case, one is an accepted abbreviation and the other is just likely (intended?) to confuse. |
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Post by superteacher on Dec 7, 2014 10:44:26 GMT
Not really. Except, I suppose in the same way that CBB is the same thing as BBC or E&A is the same thing as A&E. In each case, one is an accepted abbreviation and the other is just likely (intended?) to confuse. But the point is that you knew exactly what it meant! |
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class411
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Post by class411 on Dec 7, 2014 10:54:58 GMT
Not really. Except, I suppose in the same way that CBB is the same thing as BBC or E&A is the same thing as A&E. In each case, one is an accepted abbreviation and the other is just likely (intended?) to confuse. But the point is that you knew exactly what it meant! No, the point is I did not know what it meant. The clue is in the post asking what it meant.  I had an idea what it might mean. This forum is awash with acronyms and initialisms that are opaque to those who do not work for LU (and, I suspect, in many cases, those that do). So if someone, for no good reason, reverses a perfectly standard abbreviation, it could just be a typo or brain-fart or it could be something technical concerning railway working. |
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Post by domh245 on Dec 7, 2014 10:56:25 GMT
It might well be "Circle and Hammersmith (& city)"
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Post by superteacher on Dec 7, 2014 11:02:11 GMT
But the point is that you knew exactly what it meant! No, the point is I did not know what it meant. The clue is in the post asking what it meant. I had an idea what it might mean. This forum is awash with acronyms and initialisms that are opaque to those who do not work for LU (and, I suspect, in many cases, those that do). So if someone, for no good reason, reverses a perfectly standard abbreviation, it could just be a typo or brain-fart or it could be something technical concerning railway working. Having read your previous posts on this forum, it strikes me that your knowledge of the underground is of a reasonably sound level. I don't for one second believe that you didn't know what C&H meant in that context. I agree that H&C is the more common abbreviation, but even that is by no means official. In ant case, it's Sunday morning and getting into such a pedantic discussion as this is quite low on my list of priorities.  |
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Deleted
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Post by Deleted on Dec 7, 2014 13:09:16 GMT
Not really. Except, I suppose in the same way that CBB is the same thing as BBC or E&A is the same thing as A&E. In each case, one is an accepted abbreviation and the other is just likely (intended?) to confuse. Why would it be "intended" to confuse? What a silly thing to say. C&H is the acronym I have generally seen used - admittedly internally - since the changes to the Circle and Hammersmith & City line services as well as being the current - internal again - organisational title. H&C means Hammersmith and City not Hammersmith and Circle. If you don't know what something means there's no harm in asking politely rather than a somewhat pompous "what on earth". |
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Post by Deleted on Dec 7, 2014 13:22:19 GMT
North End is right. Although it does seem a roundabout way of inferring passengers are an inconvenience, it is a fact that the constraint on service headways at some locations is not signalling or track but dwell times (Canary Wharf and probably Kings Cross C&H are good examples). Plans to increasing the tph on the Jubilee will need to be coupled with careful management of dwell times at Canary Wharf and no doubt in the future the same will be true of some Sub Surface locations too. One positive effect of new signalling however is that headways are better managed by automatic regulation so the random long gaps that result in heavy loadings should be reduced. Hmm, I'm not entirely convinced Seltrac achieves this. It certainly works hard to prevent early running, but I can think of three specific examples of times when very minor out-of-course running has given me massive gaps in front during peak times, with consequential massive loss of time due to long unloading/loading times. Having said that, it goes without saying that the system is only as good as the signaller operating it! You're right Seltrac on its own doesn't solve this. It does generally keep even headways without signaller intervention but if there's a gap appearing in front of any train the signaller will have to intervene to hold an earlier train back or send a train out of a reversing location early. Not many options to do this on the Northern but there are plenty on the Jubilee. The interventions needed to get such trains running on each other's time are easier than for legacy signalling, as you probably know. For example reschedule the late train to run 2 minutes late and the train leaving a reversing location rescheduled as 2 minutes early and the system will hold them to this for the rest of the journey. |
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North End
Beneath Newington Causeway
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Post by North End on Dec 7, 2014 14:19:40 GMT
Hmm, I'm not entirely convinced Seltrac achieves this. It certainly works hard to prevent early running, but I can think of three specific examples of times when very minor out-of-course running has given me massive gaps in front during peak times, with consequential massive loss of time due to long unloading/loading times. Having said that, it goes without saying that the system is only as good as the signaller operating it! You're right Seltrac on its own doesn't solve this. It does generally keep even headways without signaller intervention but if there's a gap appearing in front of any train the signaller will have to intervene to hold an earlier train back or send a train out of a reversing location early. Not many options to do this on the Northern but there are plenty on the Jubilee. The interventions needed to get such trains running on each other's time are easier than for legacy signalling, as you probably know. For example reschedule the late train to run 2 minutes late and the train leaving a reversing location rescheduled as 2 minutes early and the system will hold them to this for the rest of the journey. It seems to occur from time to time at Camden southbound and Kennington northbound. In the examples I'm thinking of, a train has been held up coming south from Edgware by the train in front. Once that train has gone on to the Charing Cross branch, the delayed train has then been signalled on to the Bank branch in order, whilst at the same time a Barnet train has been held in Platform 4 which could have been run in front to avoid the gap. In this example at the time the Bank train left Camden, the train in front of that was at Old Street, which is approx 8 minutes, and this was in the middle of the evening peak! It doesn't help that the system appears to require the train leaving Camden Platform 2 to fully clear the platform and overlap before the following train gets a target point, I've seen this effect standing on the platform, and also in the cab when the target speed jumps straight from Stop to 35 mph. This is the equivalent of having a railway with every platform having multi-home signals but one stuck in the middle having only one home signal! Not impressive. I'm not sure if this is a known issue or if this may get addressed in some kind of software drop? I've seen the same happen at Kennington northbound, leave Morden on time heading for the CX branch, catch up with the train in front somewhere around the Claphams (just like you used to under manual signalling!), lose 2 or 3 minutes between there and Kennington in consequence, then cross over to the Charing Cross branch to find a packed platform at Kennington, and then lose masses of time going north. Meanwhile, at the time of crossing over at Kennington there were 2 or 3 trains in the loop which could have been run out in front. As I said, the system is only as good as the signallers, but I'm beginning to observe this starting to form a trend. |
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Post by Deleted on Dec 7, 2014 14:36:46 GMT
You're right Seltrac on its own doesn't solve this. It does generally keep even headways without signaller intervention but if there's a gap appearing in front of any train the signaller will have to intervene to hold an earlier train back or send a train out of a reversing location early. Not many options to do this on the Northern but there are plenty on the Jubilee. The interventions needed to get such trains running on each other's time are easier than for legacy signalling, as you probably know. For example reschedule the late train to run 2 minutes late and the train leaving a reversing location rescheduled as 2 minutes early and the system will hold them to this for the rest of the journey. It seems to occur from time to time at Camden southbound and Kennington northbound. In the examples I'm thinking of, a train has been held up coming south from Edgware by the train in front. Once that train has gone on to the Charing Cross branch, the delayed train has then been signalled on to the Bank branch in order, whilst at the same time a Barnet train has been held in Platform 4 which could have been run in front to avoid the gap. In this example at the time the Bank train left Camden, the train in front of that was at Old Street, which is approx 8 minutes, and this was in the middle of the evening peak! That sounds like the junction working. If it is in "normal" there is a prediction threshold during which it will hold the junction waiting for the "in turn" train to proceed. I think only if it is predicted to be less than 30 seconds (maybe 60 I can't remember) will it hold and if the predicted arrival delay is greater then the next available approaching train will be able to grab the junction. Not sure why a train would be held for longer than that - and as you point out even if the system is holding a train the signaller can intervene. It doesn't help that the system appears to require the train leaving Camden Platform 2 to fully clear the platform and overlap before the following train gets a target point, I've seen this effect standing on the platform, and also in the cab when the target speed jumps straight from Stop to 35 mph. This is the equivalent of having a railway with every platform having multi-home signals but one stuck in the middle having only one home signal! Not impressive. I'm not sure if this is a known issue or if this may get addressed in some kind of software drop? I wasn't aware of that one but this may be because the platforms are marked as "unallowed zones" that are used to prevent trains stopping part way into platforms. The train behind can't get a target point until the UZ is clear. The Jubilee set-up has recently been altered to reduce the impact of these and, provided there are no big issues identified, that change should come to the Northern at some point I've seen the same happen at Kennington northbound, leave Morden on time heading for the CX branch, catch up with the train in front somewhere around the Claphams (just like you used to under manual signalling!), lose 2 or 3 minutes between there and Kennington in consequence, then cross over to the Charing Cross branch to find a packed platform at Kennington, and then lose masses of time going north. Meanwhile, at the time of crossing over at Kennington there were 2 or 3 trains in the loop which could have been run out in front. As I said, the system is only as good as the signallers, but I'm beginning to observe this starting to form a trend. I was going to use Kennington as a good example of where a signaller could be pro-active in pushing trains out early (but with a change made to its timing to ensure it stays early, otherwise the system would try and hold it back). Same thing can be done at Willesden, Wembley and North Greenwich on Jubilee. |
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than previously. Maybe some slight timetable adjustments are needed to allow for a slightly longer stop at busy stations?
. I'm not sure anything can be done about it but it's an unfortunate side effect of being able to cram more people into S stock trains.
