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Draft graph for TT 4.1.4

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Draft graph for TT 4.1.4 19/09/2024 at 15:29 #158584
Anothersignalman
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Graph attached, prepared in Libreoffice Calc. Uses a repeating sequence of thirteen colours to represent the thirty-nine train sets operating on the mainline; does not show moves on the Picadilly line. I may be able to adjust the specific colours of each trip later to avoid following trips sharing colours, but it has to be done manually. The horizontal scale varies as required to show detail. I'm calling the graph v4.1.4 because it's a tweaked version of 4.1.3, though there may be other changes necessary before a new timetable file can be issued.

The changes against v4.1.3 as it presently exists are:
• V226-27 should depart Walthamstow 00:23:00
• V226-19 should depart Seven Sisters 18:55:30
• V236-19 should depart Walthamstow 18:50:30
• V211-31 should depart Walthamstow 00:13:00

The graph also demonstrates that V240-18E needs to be rescheduled, because it departs Seven Sisters five minutes before the previous trip (V240-18) arrives.

There are fifteen further trips which look suspiciously close, and may need their times revised:
• 08:57;30 ex Walthamstow to Brixton or 09:00;30 ex Northumberland Park Depot to Brixton
• 10:20;00 ex Walthamstow to Brixton or 10:14;00 ex Northumberland Park Depot to Brixton
• 12:22;30 ex Walthamstow to Brixton or 12:17;00 ex Northumberland Park Depot to Brixton
• 12:36;30 ex Walthamstow to Brixton or 12:32;00 ex Northumberland Park Depot to Brixton
• 13:22;30 ex Walthamstow to Brixton or 13:17;00 ex Northumberland Park Depot to Brixton
• 14:36;30 ex Walthamstow to Brixton or 14:32;00 ex Northumberland Park Depot to Brixton
• 15:05;00 ex Walthamstow to Brixton or 15:00;00 ex Northumberland Park Depot to Brixton
• 15:57;00 ex Walthamstow to Brixton or 15:55;00 ex Northumberland Park Depot to Brixton
• 16:42;30 ex Walthamstow to Brixton or 16:49;00 ex Northumberland Park Depot to Brixton
• 17:15;30 ex Walthamstow to Brixton or 17:22;00 ex Northumberland Park Depot to Brixton
• 17:35;00 ex Walthamstow to Brixton or 17:41;30 ex Northumberland Park Depot to Brixton
• 19:22;30 ex Walthamstow to Brixton or 19:17;00 ex Northumberland Park Depot to Brixton
• 21:22;30 ex Walthamstow to Brixton or 21:17;00 ex Northumberland Park Depot to Brixton
• 21:38;00 ex Walthamstow to Brixton or 21:32;00 ex Northumberland Park Depot to Brixton
• 22:57;00 ex Brixton to Walthamstow or 23:05;00 ex Victoria to Northumberland Park Depot
(These times are from the graph, so may be +/-30sec from actuals.)

@Metcontrol, are you able to check the departure times for the 31 trips listed above, and provide corrections where required?

There are also plenty of trips which must arrive 1-2min late at Brixton and Walthamstow, particularly in peak hours, because their arrival platforms are occupied.

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Draft graph for TT 4.1.4 21/09/2024 at 12:53 #158604
metcontrol
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Interesting work there. Unfortunately any of the information I can provide may have to wait a couple more days as I am nearing the end of a week of nights controlling the real thing (not the Victoria but another - I wonder which ;-) )
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Draft graph for TT 4.1.4 22/09/2024 at 18:37 #158622
metcontrol
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Right I've had a brief opportunity this evening to look at the trips you are querying.

V240-18 / V240-18E:
At some point I think a tweaking of the trip from Brixton may have occurred, which has resulted in a later arrival at Seven Sisters. The following trip has not been tweaked as it is merely a trip to the depot and has not highlighted itself as an issue. It does the job of moving said train to the depot.

Of the other 31 trips you mention, taking the following as just 1 example (I simply do not have time to go through each and every trip):

10:20;00 ex Walthamstow to Brixton or 10:14;00 ex Northumberland Park Depot to Brixton

These are 2 separate trains.
T225 departs Walthamstow 10:20:00 and runs to Brixton
T211 departs Northumberland Park depot at 10:14:00, calls at the staff platform* then runs onwards (on effectively siding roads so at reduced speed) to Seven Sisters, in time to form a service to Brixton at 10:25:30 ex Seven Sisters.

*The staff platform is a "stop as required" platform to transport staff to/from the depot at Northumberland Park. I am not sure if you know but the depot is located nowhere near any LUL station, and so some of the service/depot working etc. is tailored to provide a shuttle service to/from Seven Sisters and the depot. Dependant on whether a train needs to stop and pick up staff, the train may arrive bang on tiem or early for the onward trip towards Brixton.

At Seven Sisters there are 3 minutes between 211 and 225 departing, though 211 may arrive before its booked departure.


At the end of the day, what you have created is interesting in terms of viewing the timetable and any conflicts / service patterns throughout the day.
That said, the timetable you are analysing was created to give the sim a pretty much spot-on timetable to use. It was created using various means including the actual Working Timetable. There are over 1900 trips within the timetable, and to form the first drafts, certain methods were used to insert everything without the need to enter each and every individual train. So some trains - certainly between Seven Sisters and the depot - used template trips which were adapted and appeared through testing to all work correctly.

Whilst the timetable is pretty much spot on for the core line itself (i.e. passenger workings) you have indeed found the odd discrepancy in timings for some trips. The timetable was tested many times - trust me I tested it a lot! I would often run through most of it before Peter would add something else and I would then test again.

However your testing is obviously of a much different nature which wasn't foreseen. I would like to use the Joker card which, if you run enough sims and timetables you will come across, which is whilst the planners think things will work, and whilst everything on paper appears fine, signallers are employed in real life to overcome those very occasional times where in real life things have to be manipulated.

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Draft graph for TT 4.1.4 23/09/2024 at 08:15 #158631
TimTamToe
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For those in the UK and interested, U's programme Secrets of the Underground featured Northumberland Park Depot in the last series and mentions about the depot trains that MetControl was referring to. The episode can be found below

https://u.co.uk/shows/secrets-of-the-london-underground/series-4/episode-7/6359599808112

Last edited: 23/09/2024 at 08:27 by TimTamToe
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Draft graph for TT 4.1.4 23/09/2024 at 15:12 #158638
Anothersignalman
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metcontrol in post 158622 said:
Right I've had a brief opportunity this evening to look at the trips you are querying.

Thanks metcontrol.

I think it's evident from the last decade or so that V4.1.3 has been active that nobody would have found these issues without a graph as a reference. Unfortunately I don't have the skill set necessary to create a generalised XML to Graph translator; this required a week of manual data entry. It would also be a lot easier to spot this sort of thing if train number suffixes were a consistent number of characters, e.g. V211-02 instead of V211-2. That's something I'll look at changing in V4.1.4.

Re the time issue with V240, I'm surprised it wasn't picked up by the Timetable Validation thing; so I've opened a thread on that - https://www.SimSig.co.uk/Forum/ThreadView/55825?postId=158637

With that said, and having had a better look at the graph, I think the problem is related to the last trips of V237 and V240 possibly being swapped. Both occupy Seven Sisters platform 4 at the same time (again, not picked up by the Validator, but this would be harder to detect automatically):
V237: Finsbury 18:46;00, Seven 18:50;00-18:55;00, SevenRev 18:56;30, NorthDep 19:04;30
V240: Finsbury 18:50;30, Seven 18:54;30-18:49;30, SevenRev 18:51;00, NorthDep 18:59;00

So the solution is to push V240-18E to 18:57;00 departure, and also shift V237-18E to 18:52;30; in both cases, would 2min30sec be sufficient to clear passengers at Seven Sisters PL04?

Re the example of V211-11E form V211-11 (10:23;30 to 10:25;30) and V225-7 (10:26;30), it's three minutes between arrivals, one minute between departures. So I'm wondering if 211-11 should start from Seven Sisters a minute earlier, at 10:24;30 instead, for a 120-second headway? The line is marketed as having a 36-second headway today, but that's fairly recent. This article - https://www.londonreconnections.com/2017/ninety-second-railway-making-victoria-frequent-metro-world/ - says it historically worked on a 120-second headway in peaks, 126-second headway offpeak.

As a general principle, I'll probably end up moving the Seven Sisters trips, rather than the Walthamstow trips, to establish a minimum 120 second headway; does that sound reasonable?

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Draft graph for TT 4.1.4 23/09/2024 at 21:32 #158649
Anothersignalman
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I've now ensured that all trains are at least 2 minutes apart at Brixton, in both directions. Most changes were +/-30sec, a few slightly more than that.

I now have about 18 Walthamstow, 8 Brixton and 22 Seven Sisters potential instances of platforms being scheduled for two trains simultaneously.

For Walthamstow 1, Walthamstow 2, Brixton 1 and Brixton 2, and Seven 4, how would I go about calculating the minimum time between departure and next arrival in the same road, taking into account signal spacing, point throw time etc all under ARS? Or would it be easiest to just signal a few trains at half-speed simulation, note the times and use those measured values?

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Draft graph for TT 4.1.4 23/09/2024 at 22:34 #158650
postal
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Anothersignalman in post 158649 said:
I've now ensured that all trains are at least 2 minutes apart at Brixton, in both directions. Most changes were +/-30sec, a few slightly more than that.

I now have about 18 Walthamstow, 8 Brixton and 22 Seven Sisters potential instances of platforms being scheduled for two trains simultaneously.

For Walthamstow 1, Walthamstow 2, Brixton 1 and Brixton 2, and Seven 4, how would I go about calculating the minimum time between departure and next arrival in the same road, taking into account signal spacing, point throw time etc all under ARS? Or would it be easiest to just signal a few trains at half-speed simulation, note the times and use those measured values?
You could just do what happens in real life which often is to give the signaller an imperfect timetable and let them get on with it.

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Draft graph for TT 4.1.4 24/09/2024 at 06:43 #158651
Peter Bennet
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If there's a train every 90 second do you actually need a timetable? To what extent do the trains keep to the timetable in reality?

Peter

I identify as half man half biscuit - crumbs!
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Draft graph for TT 4.1.4 24/09/2024 at 22:17 #158660
Anothersignalman
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Peter Bennet in post 158651 said:
If there's a train every 90 second do you actually need a timetable? To what extent do the trains keep to the timetable in reality?

Peter

It's an interesting question. If you mean within the simulation, it does have an impact when considering which sets run to/from the depot tracks in what order. The same principle applies in real life for fleet maintenance cycles, keeping all sets doing roughly the same route distance on a rotating basis to smooth out wear and tear. The timetable can also be relevant when sets have to attach/divide, or if there are multiple conflict points enroute that need to be balanced; an example that comes to mind is Kensington and Newmarket junctions in Melbourne (Victoria, Australia), where you'd aim to have diverging trains crossing at both, and non-diverging trains also crossing at both. Diagram here - hhttps://victorianrailways.net/signaling/completedia/keness1918.html - so you'd want signals 4 and 23, or 4 and 25, cleared at the same time; and offset by a few minutes, you also want 3 and 15, or 3 and 48, cleared at the same time. And you space the signals, design the turnouts and set line speed at the intermediate automatics to make that scenario most likely.

If you mean from a passenger perspective, Ingvardson et al. (2018) p.300 is an interesting reference. The math is over my head, but I *think* it demonstrates that somewhere between 6min and 8min service frequencies, intending passengers change from a mostly-planned arrival at origin stations to random arrivals. This, in my view, refutes the idea that 10min (or 15min!) headways are sufficient to be marketed as "turn up and go", because people don't actually do that.

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Draft graph for TT 4.1.4 25/09/2024 at 10:25 #158663
metcontrol
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Peter Bennet in post 158651 said:
If there's a train every 90 second do you actually need a timetable? To what extent do the trains keep to the timetable in reality?

Peter
For customers no - it is why apart from on the Metropolitan Line only first and last trains are published. The system is meant to be "turn up and go" though obviously there are many exceptions to this. The Circle Line runs at 10-minute frequencies, which is way outside of people's perceptions of a frequent service when compared to the Victoria Line.

In reality yes most definitely. It is one of the Line Controller's main responsibilities to keep the line running on time to the timetable. You have to have a timetable or you would very quickly have disorder. It governs when a driver should depart a station. It relates to each driver's duty and where they should be and when. It might all seem like a random shovelling of trains down the pipe (and sometimes such lines as the Vic can certainly seem it even to those in control) but the timetable has all sorts of things relating to it that keep everything moving as it should.

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Draft graph for TT 4.1.4 01/10/2024 at 10:46 #158718
kbarber
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metcontrol in post 158663 said:
Peter Bennet in post 158651 said:
If there's a train every 90 second do you actually need a timetable? To what extent do the trains keep to the timetable in reality?

Peter
For customers no - it is why apart from on the Metropolitan Line only first and last trains are published. The system is meant to be "turn up and go" though obviously there are many exceptions to this. The Circle Line runs at 10-minute frequencies, which is way outside of people's perceptions of a frequent service when compared to the Victoria Line.

In reality yes most definitely. It is one of the Line Controller's main responsibilities to keep the line running on time to the timetable. You have to have a timetable or you would very quickly have disorder. It governs when a driver should depart a station. It relates to each driver's duty and where they should be and when. It might all seem like a random shovelling of trains down the pipe (and sometimes such lines as the Vic can certainly seem it even to those in control) but the timetable has all sorts of things relating to it that keep everything moving as it should.
(Italics mine)
Traincrew and rolling stock diagrams are very much at the heart of the issue. It brings to mind Gerry Fiennes' reflections on the London - Norwich service they put on when the Britannias were first allocated to the GE Section: that it was entirely possible to put together a set of loco diagrams and call it a timetable!

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Draft graph for TT 4.1.4 05/10/2024 at 19:26 #158753
Anothersignalman
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@metcontrol, when you developed v4.1.3, what was the reasoning for the different groups of vehicle numbering? 201/202, 203 (and presumably 204), and 205/206 reserved for trips starting from Brixton, Victoria and Walthamstow respectively makes sense, but all other sets start from Northumberland and the sequence there is non-consecutive, 211-217 then 221-227 then 230-237 then 240-247 then 250 then 271-273, so plenty of intermediate numbers not used.

Also, V227 runs morning peak only, while V247 and V250 run evening peak only, so why aren't one of those continuations of V227? Plenty of other sets enter the yard after peak and exit, same number sequence, about 5-6 hours later, and some spend even longer in the yard. It looks like:
* V227 (end 8:15am) could form V250 (start 4:15pm)
* V247 (3:45pm to 7:45pm) could fit entirely within the gap of V203 (10:30am to 11:15pm).
(Times are rounded to 15min, above.)

I think the former of these is far more likely, because the latter, V203, starts and ends the day at Victoria sidings so would need a rostered time in the depot for maintenance. Although, with that said, did the Victoria line fifteen years ago have a hot spare set kept at the depot ready to slot in and replace any other late-running set?

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Draft graph for TT 4.1.4 05/10/2024 at 20:44 #158755
TUT
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For historical technical reasons LU trains are numbered in octal (base 8, no 8 or 9). Pointless using another 'bit' for that.
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Draft graph for TT 4.1.4 05/10/2024 at 23:34 #158761
Anothersignalman
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TUT in post 158755 said:
For historical technical reasons LU trains are numbered in octal (base 8, no 8 or 9). Pointless using another 'bit' for that.

Thanks for that. It explains the lack of, for example, 218 and 219, but still leaves the question of 200, 210, and 251-253 in lieu of 271-273.

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Draft graph for TT 4.1.4 06/10/2024 at 08:05 #158762
metcontrol
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Train numbering for all LU timetables starts off initially with everything running in order and sequentially. Service patterns may then shuffle this ordering. Some lines have "self-contained" numbering systems for each service that is run.

Then, over time, this numbering is further revised when a timetable is reviewed etc. The question of why certain numbers are used can be down to many reasons. It may be that a train starting out in the evening peak ends up stabling that night in a certain place, and the number makes it stand out. It may also have a different number because, for instance, it actually only runs for a few hours then stables back in the depot.

Not only does the use of different numbers assist those trying to recover the service (as a controller it's handy to have those numbers that stand out) but from a rolling stock / depot perspective it can also dictate which physical trains are allocated to which number at the start of the day. As an example, a train due an exam on Tuesday morning, may start on Monday morning as a train which stables that night in the depot. If it is allocated to a train which "out-stables" at Brixton or Walthamstow, then by Tuesday morning it could be overdue exam and not able to run in customer service.

So the numbering may look random and it may look like certain numbers could be re-used, but there is always another reason in the background why the number itself is chosen.

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Draft graph for TT 4.1.4 06/10/2024 at 14:14 #158763
Anothersignalman
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metcontrol in post 158762 said:
Train numbering for all LU timetables starts off initially with everything running in order and sequentially. Service patterns may then shuffle this ordering. Some lines have "self-contained" numbering systems for each service that is run.

Then, over time, this numbering is further revised when a timetable is reviewed etc. The question of why certain numbers are used can be down to many reasons. It may be that a train starting out in the evening peak ends up stabling that night in a certain place, and the number makes it stand out. It may also have a different number because, for instance, it actually only runs for a few hours then stables back in the depot.

Not only does the use of different numbers assist those trying to recover the service (as a controller it's handy to have those numbers that stand out) but from a rolling stock / depot perspective it can also dictate which physical trains are allocated to which number at the start of the day. As an example, a train due an exam on Tuesday morning, may start on Monday morning as a train which stables that night in the depot. If it is allocated to a train which "out-stables" at Brixton or Walthamstow, then by Tuesday morning it could be overdue exam and not able to run in customer service.

So the numbering may look random and it may look like certain numbers could be re-used, but there is always another reason in the background why the number itself is chosen.

Hmm. When you developed V4.1.3, did you take the run numbers from the WTT or were they created fresh for Simsig?

Sets 201, 202, 203, 205 and 206 all start and end at the exact same locations, so for operational/maintenance requirements they'd need to be swapped over adhoc when those sets visit Northumberland on crew shuttles during the interpeak period; that rules out the flagging of sets for multi-day maintenance purposes. The AM/PM or short run explanations don't match the rosters as provided, since V247 and V250 are PM-only but V271, V272, V273 are mixed in with the others. If V227, 247 and V250 had unique number sequences and the others were consecutive it'd make sense. Maybe they were planned that way originally, and the form/formbys got shuffled around sometime between when the schedule was initially written and the 2009 version you'd used? i.e. perhaps V250 was the AM peak only roster, and V271, V272, V273 were PM peak only rosters? That could also explain the lack of V260-V267.

The only other reason I can think of is that perhaps it's related to which road/s the sets start or end at, at Northumberland? e.g. normal sequence roads 48-49, others 50-51 or something like that. I'd need to check if that matches the data, and it would need to be explained by specific facilities available in different parts of the yard e.g. light or heavy maintenance, wash facilities etc. distinct from regular stabling.

The reason I'm asking is because the software I have for generating graphs needs a specific number of rosters in order to display them properly. Ideally it'd be a multiple of 12, but 13 is the next-best option, so I'm trying to reduce the roster of 40 sets to 39. (38 sets, though theoretically possible, would be significantly worse for me to model.)

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Draft graph for TT 4.1.4 06/10/2024 at 15:07 #158764
TUT
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Anothersignalman in post 158763 said:
metcontrol in post 158762 said:
Train numbering for all LU timetables starts off initially with everything running in order and sequentially. Service patterns may then shuffle this ordering. Some lines have "self-contained" numbering systems for each service that is run.

Then, over time, this numbering is further revised when a timetable is reviewed etc. The question of why certain numbers are used can be down to many reasons. It may be that a train starting out in the evening peak ends up stabling that night in a certain place, and the number makes it stand out. It may also have a different number because, for instance, it actually only runs for a few hours then stables back in the depot.

Not only does the use of different numbers assist those trying to recover the service (as a controller it's handy to have those numbers that stand out) but from a rolling stock / depot perspective it can also dictate which physical trains are allocated to which number at the start of the day. As an example, a train due an exam on Tuesday morning, may start on Monday morning as a train which stables that night in the depot. If it is allocated to a train which "out-stables" at Brixton or Walthamstow, then by Tuesday morning it could be overdue exam and not able to run in customer service.

So the numbering may look random and it may look like certain numbers could be re-used, but there is always another reason in the background why the number itself is chosen.

Hmm. When you developed V4.1.3, did you take the run numbers from the WTT or were they created fresh for Simsig?

Sets 201, 202, 203, 205 and 206 all start and end at the exact same locations, so for operational/maintenance requirements they'd need to be swapped over adhoc when those sets visit Northumberland on crew shuttles during the interpeak period; that rules out the flagging of sets for multi-day maintenance purposes. The AM/PM or short run explanations don't match the rosters as provided, since V247 and V250 are PM-only but V271, V272, V273 are mixed in with the others. If V227, 247 and V250 had unique number sequences and the others were consecutive it'd make sense. Maybe they were planned that way originally, and the form/formbys got shuffled around sometime between when the schedule was initially written and the 2009 version you'd used? i.e. perhaps V250 was the AM peak only roster, and V271, V272, V273 were PM peak only rosters? That could also explain the lack of V260-V267.

The only other reason I can think of is that perhaps it's related to which road/s the sets start or end at, at Northumberland? e.g. normal sequence roads 48-49, others 50-51 or something like that. I'd need to check if that matches the data, and it would need to be explained by specific facilities available in different parts of the yard e.g. light or heavy maintenance, wash facilities etc. distinct from regular stabling.

The reason I'm asking is because the software I have for generating graphs needs a specific number of rosters in order to display them properly. Ideally it'd be a multiple of 12, but 13 is the next-best option, so I'm trying to reduce the roster of 40 sets to 39. (38 sets, though theoretically possible, would be significantly worse for me to model.)
If you go to this website

https://tfl.gov.uk/corporate/publications-and-reports/working-timetables

You can get for yourself the current working timetables and see in each of them the logic of the train numbering on the different lines. The Victoria Line one is there for you to read and see how the numbering works today.

Unfortunately I don't think the 2009 ones would ever have been uploaded but it might be possible to go back some way in time using archived pages, though I can't promise anything on that front.

Now while today's WTT might not be able to answer specific questions about 2009's numbering you can see for yourself the sort of thing that would have been a likely consideration.

The general reasons have been given in some considerable detail by metcontrol, but specifics of the kind you are after may very well be lost in time and may come down to little more that a holdover from an even earlier time or simple whim.

However if you want an accurate timetable that reflects the real timetable that did run and which metcontrol does have access to you can't play around with the numbering and will have to accept it for what it is. If you want to write a fantasy timetable very closely modelled on the real thing but made perfectly regular according to your graphing tastes you should probably commence that project at once.

Last edited: 06/10/2024 at 15:12 by TUT
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Draft graph for TT 4.1.4 06/10/2024 at 17:25 #158768
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Thanks @TUT.

Archive.org gives the January 2013 schedule here - https://web.archive.org/web/20140415231502if_/http://tfl.gov.uk/cdn/static/cms/documents/wtt-35-victoria-20-january-2013.pdf

I think this would have been the last WTT issued before the signalling upgrade went live in February 2013? I note that the departures from Northumberland are in numeric order, matching departure order, but that's out the window in the 2019 timetable you linked; in that one the 27x sequence is mixed, out of order, between the 21x-25x sequences. Both timetables also have rosters for sets 745, 746 and 747, not defined in the numbering structure and marked to "run as required"; roughly how often would these trips operate? In the 2013 schedule there are 40 sets in use, but again, the PM Peak set (252) could slot into block 203 at least in theory, so it leaves open the question of why it wasn't scheduled that way in practice.

Since this project started when I found a few issues with v4.1.3, I think the easiest short-term approach is to add a few other rosters, e.g. 204, 207, 210, until I get to the next useful multiple (14*3=42, so 204 and 210 should be enough), and just not have any trips allocated to those in my spreadsheet, with no feedback to the XML. That should let me draw the graph correctly. But I do like the idea of generating a new schedule based on the 2013 file.

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Draft graph for TT 4.1.4 07/10/2024 at 18:49 #158785
metcontrol
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TUT in post 158764 said:
The general reasons have been given in some considerable detail by metcontrol, but specifics of the kind you are after may very well be lost in time and may come down to little more that a holdover from an even earlier time or simple whim.

However if you want an accurate timetable that reflects the real timetable that did run and which metcontrol does have access to you can't play around with the numbering and will have to accept it for what it is. If you want to write a fantasy timetable very closely modelled on the real thing but made perfectly regular according to your graphing tastes you should probably commence that project at once.
Thank you for summing up more succinctly than I have.

There are lots of reasons for things LU which I have to be cautious not to stray into too deeply for fear of compromising my own position within an organisation that has always been a little less willing to divulge the details of its inner workings. There are, of course, places to source the WTTs now, and other information, but I still have to sit on the fence a bit when posting stuff publicly.

As TUT has suggested, the information within WTTs that may be available demonstrates the sort of things the Victoria Line WTT had back in 2009 plus other similar things on all the other lines. They might not go back to 2009, but the general principles remain the same.

LUL is not National Rail, and operates lots of things in a slightly different manner. However, ultimately we do need to operate timetables to accommodate a customer service, which increases for peak periods, and then paths stock to/from depots to facilitate either stabling or maintenance or preparation for services into the next peak or traffic day. There are umpteen timetables for all the sims available on this site which feature NR's way of doing what LUL do except it might be more easily visible, as there are empty stock moves and easily recognisable reasons for a train to be sent to a depot or siding.

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Draft graph for TT 4.1.4 08/10/2024 at 07:16 #158786
TimTamToe
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I'll be honest I still don't really get the point of this graph malarky.

I just enjoy the original tt, that is probably 99.9% accurate of what was at the time the timetable is based on. I'm always grateful for the knowledge of @MetControl that enabled it to be produced.

At the end of the day LU like many companies in various sectors around the world, have things for a reason. It may not make sense to those on the outside world, but is fundamental to the logistical smooth running of the company on a day to day basis.

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Draft graph for TT 4.1.4 08/10/2024 at 07:47 #158787
kbarber
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TUT in post 158764 said:

<snip>
The general reasons have been given in some considerable detail by metcontrol, but specifics of the kind you are after may very well be lost in time and may come down to little more that a holdover from an even earlier time or simple whim.
<snip>
Ah yes, the mists of time.

The letters in the second place of UK national system descriptions denote, most often, the general destination area of a train (with major exceptions for inter-regionals and locally organised service groups).

The regions, of course, disappeared entirely in 1992; the last one standing was the London Midland, all the others having disappeared in 1991.

The areas referenced were the old British Rail divisions. They disappeared under the 'Two-tier' restructuring. That took place in 1985!!!!!

Oh, and no-one ever seemed to truly get their heads around whether the letter should indicate destination or origin division. Almost always destination for Down services where the origin would be London (the London divisions all used A - and some also used B or C - as their destination code). But Up trains were ever a mix of destination and origin. That probably did depend on somebody's whim, but when a new head of timetabling arrived and changed the way things were being done, most likely the only descriptions that would obey the new policy would be new trains or those where there had to be a significant alteration (and sometimes not even then if it could be called a retiming).

As Roger Ford says (I think it's 'Informed Sources' First Law), "Never assume railways are rational organisations."

Last edited: 08/10/2024 at 07:55 by kbarber
Reason: None given

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Draft graph for TT 4.1.4 11/10/2024 at 19:58 #158800
Anothersignalman
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TimTamToe in post 158786 said:
I'll be honest I still don't really get the point of this graph malarky.

I just enjoy the original tt, that is probably 99.9% accurate of what was at the time the timetable is based on. I'm always grateful for the knowledge of @MetControl that enabled it to be produced.

At the end of the day LU like many companies in various sectors around the world, have things for a reason. It may not make sense to those on the outside world, but is fundamental to the logistical smooth running of the company on a day to day basis.

I find having an accurate graph is an easy way to prepare in advance for the next set of moves, rather than the various timetable-as-text displays. This is particularly useful when working a long section of track with multiple sub-panels to be controlled, so you know to focus on one junction for the next forty minutes, then set it to automatic and move to a different location.

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Draft graph for TT 4.1.4 13/10/2024 at 04:12 #158818
flabberdacks
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TimTamToe in post 158786 said:
I'll be honest I still don't really get the point of this graph malarky.
Anothersignalman frequently references Melbourne, Australia, whose suburban and regional controllers use the daily working timetable represented in graph format as their main planning tool. Just one way of looking at the railway, very handy for managing a double-track corridor. Less useful when there's more than two tracks.

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