Conflict at 4 Track Rail Platform

[harsha.g3]

I have used "Train Holden Station" from the workshop which consists of 4 tracks in the station. Can someone suggest me how to merge 4 tracks into 2 tracks before and after the station along with signalling system. Trains should run in both ways and I have tried all possible solutions with blocks and chain signals but getting conflicts like at some instance, two trains are coming on the same track from both sides at a time. Give me solution for this.

[Bastardo]

I usually let three tracks enter/exit my 4-track stations, to/from a two-track mainline railroad. The two outer tracks go in, while the middle track goes out. At some point I split the middle track into two. Closer to the station building I let the two outer tracks be mixed, with a connection back to the closest section of the splitted middle track. This way any train can safely return back, while the entering trains are put to wait.

On the other side I use a similar setup.

Just make sure you keep some space on each side of the station, so that you can have at least a full train standing in queue waiting.

[fjorkar]

hello Bastardo could you please send a photo of your setup ?, your solution fascinates me

[Bastardo]

Next week I will try to upload a screenshot of the setup.

[fjorkar]

Originally posted by Bastardo:

Next week I will try to upload a screenshot of the setup.

[Bastardo]

Ok! Managed to upload a screenshot of the setup somewhat earlier than anticipated :)

In this example the 4-track station is connected to the 2-track mainline railroad on both sides of the platform. On the right in this picture the mainline is also supported by a parallel third track for additional inbound traffic.

The role of the middle track could be switched/reversed, depending on which of the tracks from the mainline that it connects to/from.

https://steamcommunity.com/sharedfiles/filedetails/?id=2558876353

[barry.zandstra]

Originally posted by Bastardo:

https://steamcommunity.com/sharedfiles/filedetails/?id=2558876353

That appears to be an excellent terminal station. However, if this setup is mirrored on the other side, and used as a through station, there will be deadlocks. The train on the bottom track that is now cleared to proceed to the bottom platform could pass the blue pre signal. At that point, the platform is still empty so the next light is green. Meanwhile, on the left, the same platform is obviously empty, because it's the same platform. The pre signal on the left, therefore, will be blue. So a train from the left could proceed towards the same platform, after the first train already started moving.

When (not if) this happens, one of the trains enters the platform first, causing the other train to get a red light, forcing it to wait right on the switch. Unless the first train reverses out, this is a deadlock that must be manually broken by the player.

A system with dedicated platforms per direction is more reliable (if you need a through station). Another fix is to replace the mixed signals at both sides of the platform with chain signals, but this obstructs traffic flow. Or make traffic from both directions enter on one side and exit out the other.

[Bastardo]

You are probably correct. It depends on how much of your traffic that is bound for passage through. I have experimented with other and more advanced track layouts but often find this setup being the best compromise. At least when you run with a mixed fleet of local, regional and intercity trains. Here I have had some 15 trains connected to the station without any major mishap, but if you run with a bigger share of intercity (or other stop-and-passage trains) I would recommend changing two of the four station tracks to single direction only (one pointing in each direction). But here is where the train pathfinding code still fails, as the other trains that are set to change direction after the station stop don’t recognize which tracks that are unfavorable to enter.

So again, this is my best compromise to what we have to play with in terms of pathfinding at the moment. Perhaps to combine with a not-too-distant circulation track on each side of the station area, where trains could change their direction if required.

[The Mustachioed Marxist]

Originally posted by barry.zandstra:

Originally posted by Bastardo:

https://steamcommunity.com/sharedfiles/filedetails/?id=2558876353

Another fix is to replace the mixed signals at both sides of the platform with chain signals, but this obstructs traffic flow.

How does that obstruct traffic flow? What case am I not seeing?

[harsha.g3]

Thank you for the screenshot, i tried but still conflict occurs at when 2 trains are coming to occupy from both ways on a single platform at same time

[barry.zandstra]

Originally posted by The Mustachioed Marxist:

How does that obstruct traffic flow? What case am I not seeing?

Remember, the setup is mirrored on the other side, since we are talking about using this as a through station.

Imagine the train on the bottom track advances, and reaches the switch. A train approaching on the lower track from the other side is now unable to enter the switch on the left, since there is no clear path to the next block signal, so the chain signal will be red. You are blocking the switch for arriving trains on both sides if either is engaged, irrespective of whether the train on the switch is arriving or departing.

Furthermore, after a train departs from the platform and clears the switch, it occupies the first block past the switch. This means the signal must be red, which prevents any trains moving in the same direction from entering the switch or proceeding from the switch to the platform, since the next block signal ahead is red.

If you make the platforms all one way, on the other hand, you don't need all those chain signals, so trains can run much closer together. (This does have the drawback that trains can't reverse at the station.)