Started by Sirius, August 20, 2019, 10:52:05 AM
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Quote from: Freahk on August 29, 2019, 05:14:05 PMAs long as the network is small and there are no level crossings with roads, which is always true for early networks, there won't be any factors that you can't calculate.
QuoteMy first network was of that exact type. It had two lines and 5 trains on it and worked perfectly without deadlocking for 15 ingame years, which is much mre than any other type of network I ever yet created.Well for scheduled stops you have to set the shift anyway. Setting the max tolerable time would be just another one. However, one could set some default value for new scheduled stops, so for scheduled networks one could simply set this to 0 manually.
Quote from: Freahk on August 29, 2019, 10:23:32 PMYou are right, level crossings before 1835 don't have gates but still work the same as later level crossings with gates.However these aren't available in very early rail transport from ~1750 to ~1770Due to this restriction early railway lines have to be designed without level crossings.
Quote from: Freahk on August 20, 2019, 10:52:05 AMThis is often the case when a track is used by intercity and local trains. The local trains schedule will let the intercity train pass while waiting at a station.Currently, if the local train is late, the intercity train can still overtake but due to the fixed schedule slot, the local train will wait for the next slot instead of leaving the station when it could still get back in time a few stations later.
Quote from: Octavius on December 27, 2019, 09:13:54 PMActually, that will only work as long as the passing loop is long enough and has an intermediate signal to hold two local trains simultaneously, else the next intercity will get stuck behind the local train.
Quote from: Octavius on December 27, 2019, 09:13:54 PMAnother consideration is what to do when the train has excessive delay. Waiting for the next departure slot of that line only really works if it's the only line serving that platform and there's room to keep a second train on that line for a short while without causing more disruptions.
Quote from: jamespetts on December 29, 2019, 03:53:48 PMbut there is a tolerance (I cannot now remember what it is) such that if it has missed a slot by a small amount, it is assumed to be late, and will depart as soon as it is ready. Is what is being requested here the ability to customise this tolerance per stop?
Quote from: Freahk on December 29, 2019, 05:16:19 PMI guess I confused "delated" with "belated", alternatively "late" or "delayed", don't know which fits best. That means a train arriving too late at a station to get its schedule.
QuoteAbout the schedule:Six schedules a month (6:24) means a train will leave every 64 minutes, so at 0:00, 1:04, 2:08, 3:12, 4:16, 5:20 a train will depart. That's exactly the same as departing every hour at 0:00 given 6:00 per month instead of 6:24 per month, so I don't really see any difference in between "convoy X leaving stop Y at time Z" and a departure frequency.This is roughly what I requested. However, to disallow multiple trains departing late, we need to remember if a train used that slot already.
QuoteRanrans suggestions go further by allowing trains to travel slower that possible if they are in time, so allowing time reserves in between stations instead of only time reserves by waiting at a station.Whilst this can be useful in some situations, I don't think it's worth the effort unless fuel consumption gets implemented.
QuoteThe third point is in fact very useful independently of schedules but I guess it's simply another signalling system/working method than the one used in the UK.
Quote from: jamespetts on December 30, 2019, 11:04:25 AMI am not sure that I follow - what is the thing that is useful independently of schedules?
Quote from: Freahk on December 30, 2019, 11:46:27 AMIt will allow multiple trains to travel nearly constantly at the same speed as the slow train occupying the track instead of stop-and-go ing, so the faster trains don't have to accelerate from 0 as soon as the slower train left their track.This would be helpful e.g. for cargo trains that usually don't use fixed schedules but instead use wait for load.
QuoteAdditionally, if one would modify choose signals (or create a special sign, signal or waypoint) to route a train causing a speed restricton to the alternative route, this would greatly improve passing loops.
QuoteI don't think setti g a fixed maximum speed to save fuel is a good idead with schedules in mind. Grains being scheduled for lower speeds have a great chanche to get back in time using a higher speed, so I guess setting a preferred arrival time as an arrival shift in schedules is a better idea.
Quote from: jamespetts on December 30, 2019, 11:55:52 AMI can only imagine it being extremely difficult to get a reliable algorithm for convoys attempting to achieve a particular arrival time.
Quote from: jamespetts on December 30, 2019, 11:55:52 AMBut how in practical and economic terms would this actually add anything useful? What would be better about a constant speed?
Quote from: jamespetts on December 30, 2019, 11:55:52 AMI am not sure how you imagine that this would work
Quote from: jamespetts on December 30, 2019, 11:55:52 AMand how it would be of assistance;
Quote from: Freahk on December 30, 2019, 06:53:45 PMWhile this is true, the algorithm does not need to consider other trains blocking the route. The gain of target aival times would be load independant travel times, so it is much easyer to create schedules where the track will be free. The only cases where this is not possible are highly used tracks and unscheduled lines at the track. For both, buffer times in the next station or upcoming less used tracks are required anyway.
QuoteIt will increase the traffic flow, thus slightly increasing tracks capacity. More importantly it will greatly improve passing loop relyability because the following, faster train will start overtaking at the same speed as the slower one.Economically we will get increased track capacity, which can make a difference if you need to build an additional track.
QuoteWhen fuel consumption is implemented, this will also have a huge impact at fuel consumption.
QuoteIf a signal showing a speed limitation is passed, the train causing that limitation gets roted to the alternative route if the alternative route is free.Trains entering the alternative route will most often slow down due to curves, so it takes much longer to overtake if the overtaking train has to slow down. The other way round the slowdown of the slower train would even assist the process of overtaking for both trains. The faster one can overtake faster and for the slower one it is less likely to come to a complete halt.
Quote from: jamespetts on December 30, 2019, 10:30:15 PMI am still not sure that I understand the real economic significance of the signalling behaviour described compared to the existing signalling behaviour,
Quote from: jamespetts on December 30, 2019, 07:04:18 PMI do not understand this, I am afraid. Presumably, the train causing the restrictive aspect has already passed the signal, so how would one route that train retrospectively? Or have I misunderstood what you meant here?
Quote from: jamespetts on December 30, 2019, 07:04:18 PMEven not taking into account conflicting vehicle movements, this would still be extremely difficult to code.I am not sure that I fully understand how speed signals as such (i.e. something approximating the German signalling system) are able to do this; and in any event, this does not deal with the insuperable obstacles to implementing an economically meaningful representation of speed signalling in Simutrans-Extended set out above.I do not think that speed signals, as opposed to a means of limiting vehicles' top speed between pairs of stops in their schedule, is the right way to go about doing this, as it is dependant on players using a signalling system that implements speed signalling (i.e. none of the UK systems) and it gives the player no control. It also requires a large amount of other work to be done to implement speed signalling when far less work would be required to implement a schedule based speed limit system.I do not understand this, I am afraid. Presumably, the train causing the restrictive aspect has already passed the signal, so how would one route that train retrospectively? Or have I misunderstood what you meant here?
Quote from: Freahk on December 31, 2019, 03:57:36 PMI guess I need to illustrate it as soon as I'm home. In the meantime I will try to explain it from my smartphone.That choose signal/passing loop functionality is not specific to speed signalling. It also works well for any other signalling system including moving block.To make this work properly, a train has to look a few additional blocks or tiles ahead than reqiuired for working methods path reservation. iIf a train in that range is detected as being slower, that train will be marked as blocking. At a choose signal such a train will assume the path of the faster train behind the first junction after the choose signal as reserved, thus starting an alternative route search.The blocking marker will be removed from a train if it was routed to an alternative route or it passed a given number of blocs without being marked as blocking again.
QuoteSpeed signalling aims at keeping trains speed more constant than n-aspect signalling. At least in simutrans-ex, a train following a slower one will accelerate/decelerate all the time, which is extrememy fuel consuming even for modern electric trains.A scheduled maximum speed won't help much here as a slower train blocking a faster one is most often not something one would schedule but the cause of the faster train being belated.
Quote from: Freahk on December 29, 2019, 12:59:54 PMIn Germany those trains usually continue delayed after reversing at their terminus, where they have a relatively long waiting times so they can compensate a relatively huge delay.Sometimes, when they have a huge delay, trains will reverse eralyer. I don't know of any line that is missing intermediate stops to catch up.
Quote from: Freahk on December 29, 2019, 12:59:54 PMI am not quite sure if conditional delay dependant schedules are great idea in simutrans-ex. What should we do with passengers that want to leave at a skipped station?
Quote from: jamespetts on December 29, 2019, 03:53:48 PMIf we were to try to simulate speed signals in Simutrans-Extended, it would be necessary somehow to constrain the distances between signals very precisely: if the distances were too short for the speed, this would amount to an exploit, since the real life reason not to do this (that the trains would not stop in time for the danger signal and may crash) is not simulated. If the distances were too long for the speed, the player would be penalised as the trains would travel more slowly than necessary for part of the distance. This is not really a practical thing to do, so speed signalling has been omitted.