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Post by jimbo on Apr 14, 2021 0:42:20 GMT
Moved from the SSR Resignalling thread: The only way to smooth out run-of-the-mill issues is to do just enough intervention to get things to a point where breathing space in the timetable gets everything back to where it should be. Otherwise the service will simply never recover - there’s only so many reversing points, and only so many reform opportunities! Can someone provide a short explanation of how to reform a service?
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North End
Beneath Newington Causeway
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Post by North End on Apr 14, 2021 2:46:07 GMT
...... The only way to smooth out run-of-the-mill issues is to do just enough intervention to get things to a point where breathing space in the timetable gets everything back to where it should be. Otherwise the service will simply never recover - there’s only so many reversing points, and only so many reform opportunities! Can someone provide a short explanation of how to reform a service? Essentially the controller or signaller will pick a location where crew reliefs are booked, make a list of what trains are approaching, note down for each train how late it is and whether or not is has a crew relief, and look to see whether there are opportunities to renumber trains in such a way which by the end of it will have made the late running situation better. The key to doing this is making use of the trains which have crew reliefs, as this gives you a fresh driver who you can assume will be ready to make up any train into their own at the time scheduled. The ideal scenario is to push all the late running onto one train, and then do something else with that train (eg turn it short, or even miss a whole round trip). You’ve essential then “righted” several trains without passengers being aware, and only one or two get hit with being turned short. So take somewhere like Golders Green. Ideally you’d only touch stuff on the northbound as (1) that’s where the crew desk is so it can be closely monitored, and (2) you don’t change destinations for southbound passengers. As an example, you have a sequence of trains on a 3-minute headway with a small amount of out-of-order running and a few running slightly late. 001 +6 no relief 002 +6 relief 003 +6 relief 004 +5 relief 006 +3 no relief 005 +7 relief You could do something like 001 x 002 (departs +3 with fresh driver) 002 x 003 (departs +3 with fresh driver) 003 x 004 (departs +3 with fresh driver) 004 x 005 (departs +2 with fresh driver) 006 - 006 (departs +3, left as is) 005 x 001 (reverse Golders Green, depart in correct order, driver gets off original train and picks up new one when it arrives) By doing the above sequence of alterations, the late running has been reduced to a point where each train is close enough to being back on time that providing it makes up a minute in the run up to Edgware and back down, they will fit into the correct order at Camden, and are likely to reach their next destinations on time. Only one train has had to be turned short. Southbound passengers should to all intents and purposes see a full service apart from one cancellation from Edgware, and once that slots in everything will head south in its right order. Notice how I’ve had to be careful with what is done with trains 001 and 006 as these two don’t have a crew relief. I can still do things with them, but only if the booked driver gets there before their train is made up. For train 001 this is fine as the driver is already there before he takes over 005 and makes it 001. 006 is not being touched, so no problem there. There’s no right and wrong way of doing things, and no doubt it might be possible to find a way of getting everything on time with perhaps a Colindale reverser thrown in, or perhaps leaving one train go north late and then divert via Charing Cross on its next trip, or perhaps reverse at Tooting Broadway, or whatever. Something like the Northern is a delight as the range of options is literally endless, so you could have a batch of late running and if there’s time for the signaller to spend a few minutes thinking and planning, it can be possible to sort out 10 or so trains in one hit by using a combination of all the various options. If there’s severe late running then it’s more a case of looking at what drivers are ready to take over a train and making up accordingly, but this is more of a firefighting measure. |
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Post by d7666 on May 19, 2021 12:39:13 GMT
I only wish min line could do something along these lines on high frequency routes like Thameslink.
Time and time again I have been in TL core with an entire 15 min interval service group (like northbound to Bedford) running 12,13,14 min late. If they could only make them all 15 late, and renumber, and lose just one by turning it back, at Luton say, it would all be back in place.
The problem there though is again drivers - they are then all 15 min out of place. But that's not a blocker, it could be sorted.
Yes, I am aware the performance politics and contracts of main line TOC are not the same, where every single train is penalised for late at terminal destination - and this is more likely the over riding reason. The main line solution is skip stops to try and make up late runners at final destination, but this does nothing for passengers at or wanting to get to intermediate stations. But I am sure if LU type control was applied to routes like TL it could recover from traffic perturbation much more quickly.
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North End
Beneath Newington Causeway
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Post by North End on May 19, 2021 16:12:23 GMT
It does happen on Thameslink, but at the termini. As you say, you can only do things where there is a crew relief planned. On the Great Northern side you could theoretically do something at Finsbury Park on the up side with the Moorgate service - subject to every train being the same length and having crew changes there you could renumber a load of trains and then, for example, turn one at Drayton Park.
The other issue is that renumbering trains means the stock concerned may finish in a different location. Even on LU this can be a problem if a depot are expecting a particular train. Whilst control are entitled to take the view “delivering the timetable comes first”, the trouble is that this can then mean a no ok stock the next day when the train which was due an exam has ended up outstabled unexpectedly and the depot couldn’t do the exam. This is why it’s always a case of doing as little as possible to give the service the opportunity to recover naturally, rather than chasing every last minute.
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rincew1nd
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Post by rincew1nd on May 19, 2021 21:32:42 GMT
The main line solution is skip stops to try and make up late runners at final destination, but this does nothing for passengers at or wanting to get to intermediate stations. AIUI a train is only "on time" if it arrives at its destination and has called at all booked stations. If it arrives within the time margin but has skipped stops to make up time then it doesn't count in the punctuality figures. |
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North End
Beneath Newington Causeway
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Post by North End on May 20, 2021 0:03:00 GMT
The main line solution is skip stops to try and make up late runners at final destination, but this does nothing for passengers at or wanting to get to intermediate stations. AIUI a train is only "on time" if it arrives at its destination and has called at all booked stations. If it arrives within the time margin but has skipped stops to make up time then it doesn't count in the punctuality figures. As ever the question is whether it’s worth taking that ‘hit’ on one service if it avoids a load of reactionary or consequential delays. Control *should* be taking into account a range of factors, not least what the train and driver are scheduled to do on the next trip. It’s like playing snooker - it isn’t about being able to pot the current ball, but looking ahead to set up subsequent shots. Having said that, I’ve seen some very dubious non-stop runs on the mainline, not least stops removed but the train getting stuck behind another train so ending up getting signal checked in the very platforms being skipped! (Yes Southeastern, looking at you here!) |
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Post by norbitonflyer on May 20, 2021 6:45:05 GMT
Having said that, I’ve seen some very dubious non-stop runs on the mainline, not least stops removed but the train getting stuck behind another train so ending up getting signal checked in the very platforms being skipped! (Yes Southeastern, looking at you here!) South western do that too (SWT,SWR,it's all the same because it's actually the NR "control" who seem to be in charge and the staff on the ground are apparently expected to comply even when it is obvious the Orders From On High will make matters worse). Also skip stopping in the peak flow direction so the return contra-peak flow will run on time, which may improve their stats (because the second train will be on time) but inconveniences far more passengers. The worst excuse though is when they terminate a train short of a useful interchange (e.g Kingston instead of Wimbledon) "to relieve congestion". The congestion on the platforms doesn't seem to be a consideration! |
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Post by d7666 on May 22, 2021 14:37:15 GMT
Having said that, I’ve seen some very dubious non-stop runs on the mainline, not least stops removed but the train getting stuck behind another train so ending up getting signal checked in the very platforms being skipped! (Yes Southeastern, looking at you here!) This happens on Thameslink too. Classic example now are the xx:16 and xx:46 Luton Rainhams when the incoming service is late into Luton; if it arrives more than a couple of minutes after it's outbound should have gone, the general reaction is non-stop it to St.Pancras. I find one of these every month or so. What then happens is one of two things [1] it stays on the slow Lines, catches up with a St.Albans all station starter by about Mill Hill, and trails that one's tail lights on single yellows all the way to Blackfriars, or, [2] it sits in platform at Luton or Harpenden for several more minutes waiting free path to get on the Fast Lines, then sits again at West Hampstead waiting to get back, often ending up behind the very same StAlbans starter it would have followed as in [1]. Anyway, that was a digression. I was more aiming at wishing TL could do more of the LU type reforms when the entire service is late. I was not getting at sorting out just one train (which is what skipping stops does), but when the whole pattern in one service group is all late by a similar amount of minutes that approaches that service frequency i.e. every 15 min but they are are 12-14 min late. As a TL commuter, that happens so so often, been there, got more than one tee shirt. I think that is the thing the main line delay attribution regime is overlooking the case where the delay to consecutive trains is of the same order as the service frequency - which is where reforms make more sense. LU in this sense is high frequency everywhere, even out in the sticks of Buckinghamshire and Essex. So it works. |
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Post by zbang on May 22, 2021 17:35:02 GMT
I'd think that was a worse problem as with longer intervals, getting drivers in the right places after their breaks would be much harder. Or you have some drivers waiting an hour or so to pick up their next service. (Have to think on this.)
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The only way to smooth out run-of-the-mill issues is to do just enough intervention to get things to a point where breathing space in the timetable gets everything back to where it should be. Otherwise the service will simply never recover - there’s only so many reversing points, and only so many reform opportunities!
