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| Timetable autocomplete? 04/01/2023 at 23:33 #149986 | |
Robyn
74 posts |
Evening, I'm progressing more with the WTT writing however a lot of the timetables that I like to write are from what I would consider to be the 'Golden Age' of the railways. I've noted, particularly in the W.R., the 'mandatory' timing pts have changed.. significantly, for example, on Plymouth: Brent WAS a mandatory timing point however it doesn't exist anymore so it was shifted to Aish, yet Aish is not in the same location so I can't use the timings through Brent. Similarly, Ivybridge has moved and is now considered a 'mandatory' timing point where previously it wasn't. On Exeter: Dawlish Warren was not a mandatory timing point but now it is. etc.. What I would like, and would help me a lot: Is basically a button/utility that allows me to pick a start and end point, and fills in all the mandatory timing points AND the passing times depending on the train type. Does such a thing exist? Could such a thing ever exist? Is there a faster way that I'm missing, as currently I'm having to work out the point-to-point times based purely on guesswork and a predicted average speed. Which, is hardly ever accurate. Am I missing something? 7-5-5, closing of comment Log in to reply |
| Timetable autocomplete? 05/01/2023 at 00:49 #149988 | |
JamesN
1611 posts |
No such thing currently exists in the sim. As to making it exist. It would be impractical to develop it natively within the program. Far too many options and variables - all of which would have to be “guessed” exactly as you are currently doing, but for EVERY train type and EVERY sim. That’s 1’000s if not 10’000s different sets of timings to be worked out. Forgive what might be an obvious suggestion, but do modern timetables not contain a rough indication of the timings you’re after? Your old-school point-point times from say, Totnes to Plymouth will likely be fairly similar to today; so can you not just use those intervals in the modern TT between the modern timing points to educate your guesswork and be in a close-enough ball park? Log in to reply |
| Timetable autocomplete? 05/01/2023 at 01:22 #149989 | |
DonRiver
166 posts |
I've been using Luke Briner's SimSig Importer for creating WTTs from spreadsheets. I've created an elaborate spreadsheet which lets me enter WTT timings pretty much as they appear in the real WTT (actually - I enter the train's start time and it creates initial intermediate timings based on time intervals between stops I can adjust per train). It pads out the WTT timings with any required for the sim, including entry points. I can then copy, paste, and tweak this data in a format SimSig Importer understands, and make 95% of the timetable in one go. I've used a bunch of formulas to assist with generating timing points automatically, inferring the timings for the SimSig mandatory ones based on a fixed offset from one of the official WTT timings. For example, District Line trains to Wimbledon, I enter in the time departing East Putney, and my spreadsheet infers the train must enter at the Westbound District entry point one minute earlier than this. But if you're doing a timetable for the time before clockface schedules you could just enter every timing point by hand and it'd still be easier doing this in a spreadsheet than in the F4 timetable editor! (named for the one in Tasmania, not in Russia) Log in to reply |
| Timetable autocomplete? 05/01/2023 at 02:01 #149990 | |
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Robyn
74 posts |
Quote:Forgive what might be an obvious suggestion, but do modern timetables not contain a rough indication of the timings you’re after?Ok this is an entirely valid question/idea. And the answer is.. Kindof? I input the times exactly as is written in the WTT documents that I have and I run heavy, very low acceleration steam train (which one would guess would be the one that would take the most time point-to-point?) and the train ends up arriving at point B a good 15 mins ahead of when it should be even when accounting for timetable allowances. I have to shift departure times back by almost 10 minutes in some cases in order for the train to arrive 'on-time' and not be ludicrously early. Which.. pardon my saying so, doesn't seem right to me? I've looked at other 'Golden Age' WTTs (Cross '55) (Exeter '22) and this doesn't seem to be a problem for them so I'm not sure what I'm doing wrong. And I don't think it would be anywhere near a complicated as it's made out to be. As the sim knows how long it will take the train to pass each point, because it has to simulate it. So create a little 'thing' the checks the train type, and runs an invisible, mock train between those points, with the length and characteristics on like 500x speed and just calculate the time taken in ideal circumstances. Then spit that number back out into the timetable editor? It may shock you all to know I am not a developer so I have no idea how practical any of this actually is. But this is how I would go about solving it. 7-5-5, closing of comment Last edited: 05/01/2023 at 02:02 by Robyn Reason: None given Log in to reply |
| Timetable autocomplete? 05/01/2023 at 03:00 #149991 | |
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Dionysusnu
580 posts |
RobJ in post 149990 said:Have you checked the maximum attained speed of the train during its run? I imagine the linespeed may well be higher nowadays, maybe by a significant amount even. It might help to lower the train category's maximum speed to the timetable era's maximum linespeed, if you have any resources for what the situation was back then. Log in to reply |
| Timetable autocomplete? 05/01/2023 at 09:26 #149993 | |
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kbarber
1764 posts |
Dionysusnu in post 149991 said:RobJ in post 149990 said:Also worth knowing the degree to which gradients are simulated in the sim, particularly if you've got the South Devon banks in your timetable. Back in the day, Dainton was a known terror with double-headed Kings on the 'Limited' probably struggling to manage 30mph (you'd need some old logs like they publish in 'Locomotive Practice & Performance' to get actual speeds) for the bulk of the climb; if the sim doesn't include full gradient data you may well find even a heavy steam train floats up there at 60mph or more.Have you checked the maximum attained speed of the train during its run? I imagine the linespeed may well be higher nowadays, maybe by a significant amount even. It might help to lower the train category's maximum speed to the timetable era's maximum linespeed, if you have any resources for what the situation was back then. Log in to reply |
| Timetable autocomplete? 05/01/2023 at 10:30 #149996 | |
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bill_gensheet
1431 posts 
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On Kings Cross, I found a 60mph maximum was a good start, but that is flat-ish. You could also set up an extra category for 'uphill steam' that you give 30mph to, and change train categories along the way. I doubt it would be perfect, but may be within the real life vagaries of train performance. Log in to reply |
| Timetable autocomplete? 05/01/2023 at 10:54 #149998 | |
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clive
2799 posts |
RobJ in post 149990 said:Actually, no, the sim *doesn't* know how long the train will take. The simulation (well, the core code) actually simulates the behaviour of the train as it goes. So each simulated second it tries different amounts of acceleration or braking, within the train's limits, determines how far the train will move with that change (also allowing for things like gradients), then checks that the train obeys all speed limits it's currently within and is still able to brake in time for any other speed limits or stops coming up. Plus anything else I've forgotten (e.g. defensive driving). All this is done on the fly - after all, a route clearing or the user putting a signal back will alter the answers. There is *no* concept of section times in SimSig. The only way to find them out is to do what the real railways (should) do: run a train on clear track and note the times. RobJ in post 149990 said: It sounds like even the lowest acceleration rate available is too high. Better simulation of train dynamics is somewhere on my huge list of things to do. Log in to reply |
| Timetable autocomplete? 05/01/2023 at 11:28 #150000 | |
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Robyn
74 posts |
kbarber in post 149993 said:Dionysusnu in post 149991 said:Going back to the Limited and gradients, I'm fairly sure the gradients are done properly as if I bung a 60mph heavy freight up Largin from Bodmin Rd(Parkway) (1:50ish rising if memory serves correctly?) it's doing no more then 15mph by the time it tops the summit at Largin and St Pinnock, which is correct.RobJ in post 149990 said:Also worth knowing the degree to which gradients are simulated in the sim, particularly if you've got the South Devon banks in your timetable. Back in the day, Dainton was a known terror with double-headed Kings on the 'Limited' probably struggling to manage 30mph (you'd need some old logs like they publish in 'Locomotive Practice & Performance' to get actual speeds) for the bulk of the climb; if the sim doesn't include full gradient data you may well find even a heavy steam train floats up there at 60mph or more.Have you checked the maximum attained speed of the train during its run? I imagine the linespeed may well be higher nowadays, maybe by a significant amount even. It might help to lower the train category's maximum speed to the timetable era's maximum linespeed, if you have any resources for what the situation was back then. I think it might just be how clive suggested it, that work needs to be done on simulating train chars better. I will sift around for a sectional appendix but I think I may come up blank on that front when working out linespeeds, fairly sure like everything else in Cornwall irl it hasn't changed in like 100 years anyway. I guess what i'm going to have to do is just brute force the times out of the sim by running test trains over every route, and save them in a spreadsheet. Interesting to know how the sim 'simulates' trains, like I said, not a developer, but just how I thought it might've been done. DonRiver, would you interested in disclosing your spreadsheet for calculating timing pts? As I have tried to make one myself but it didn't really work practically. 7-5-5, closing of comment Log in to reply |
| Timetable autocomplete? 06/01/2023 at 17:13 #150057 | |
GeoffM
6380 posts |
On ARS sims (and occasionally non-ARS sims) the timetable validator can automatically insert certain missing locations. It's simply a case of "if location A is followed by location C then insert passing time at location B at x% of the way timewise". On plain, level track with consistent speed limits, that % is simply the percent of distance from A to C that B is located (depart/pass time at A to arrive time at B). There are some quirks like pathing allowances but that's another subject for another day. Broadly speaking, it's "good enough" as an estimate for ARS at least. Where gradients or varying speed limits are involved then it's complicated further - if you wanted it mathematically perfect, that is. If not, then best estimate. As for how train characteristics are concerned, originally we literally sat on trains on level ground with no impediments to acceleration with stopwatches and speed trackers to form acceleration curves (one for each of the acceleration/braking rates). They are then adjusted for gradient and weight. When I worked at TRE we had a business need to get actual performance graphs from the train manufacturers but they refused to give them to us - confidential commercial blahblah. One company claimed to send us genuine ones but I found that they were fake (the biggest clue being massively exceeding the speed limit entering a major station), challenged them on it, and they admitted it came from their simulator. Sigh. Nevertheless, for most trains, I think our trains do reasonably well. Granted there are some cases that don't, but they can usually be tweaked. SimSig Boss Log in to reply The following user said thank you: jamesrail |
| Timetable autocomplete? 10/01/2023 at 09:34 #150100 | |
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chrisdmadd
255 posts |
Geoff, can you help me with something, when you edit a TT and validate it mid session and lets say you miss a location, the 'Next key locations' window opens and gives you the options for the missing location to be added. Would it be possible to be able to click on those locations and select one? Whenever i seem to do this they are greyed out and you cant actually select an option. This would save a bit of time!
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| Timetable autocomplete? 10/01/2023 at 12:41 #150101 | |
58050
2660 posts
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GeoffM in post 150057 said:On ARS sims (and occasionally non-ARS sims) the timetable validator can automatically insert certain missing locations. It's simply a case of "if location A is followed by location C then insert passing time at location B at x% of the way timewise". On plain, level track with consistent speed limits, that % is simply the percent of distance from A to C that B is located (depart/pass time at A to arrive time at B). There are some quirks like pathing allowances but that's another subject for another day. Broadly speaking, it's "good enough" as an estimate for ARS at least. Where gradients or varying speed limits are involved then it's complicated further - if you wanted it mathematically perfect, that is. If not, then best estimate.When you create a timetable on Derby[which is non ARS] you put the data in from the WTT & when you press validate it adds automatically a passing time at Clay Mills Jn. The only difference is that for locations you've chosen & added in the location name appears in capitals, but those locations added in once you press validate are in lower case letters except for the first character of each word in the location name. Log in to reply |