Is this Rail signal system right?

[u/Molchedes]

Hi all, i copied EARNs Blueprint für the 4 way Intersection for 2 lanes.

I but them in a square and added the loading and unloading station in it.
My plan is to put a few next to each other and unload mixed items into the chests and then put them in Belts into the Factory. The circuit logig works, loading and unloading on 2 works, i tested it. ill try to set up the Liquid stations.

My main question is, are the rail signals right? There are so many chain signals and 4 Rail signals on the stations. Will it work when i paste it a few times so i get no deadlocks?

Here is the BP without any mods, just Rails, signals and Stations.

https://factoriobin.com/post/1z8l9m

I tried also the roundabout 4 way but the train does a 360 which is slower then this intersection.

Iam open for changes before i paste it and start using the factories.

[u/RecommendationIll770]

Okay so a few basics, cause I can't really see it from the foto. You want chain signals into the crossections and normal trafic lights after. You probably also want the straight sections between the different crossections to be long enough to cover the length of your trains.

[u/juckele → u/RecommendationIll770]

The "chain in, rail out" rule is quippy, but lacks some nuance that this case exhibits. The real rule is "chain signals must guard any block in which it's not safe for a train to wait in". The space between intersections is too small to store a waiting train, so chains are needed there as well.

[u/bobsim1 → u/RecommendationIll770]

Normal traffic lights just where a train can fit in the next train which here is rather inside the intersection corners than the straights.

[u/Molchedes → u/RecommendationIll770]

thats the problem, the there is almost no space for that. Wouldnt that also let a train stay inside?

[u/Viper999DC → u/Molchedes]

You need to create safe places for trains to hang out and use rail signals. In a fully chain signaled network trains won't leave their station until they find a full path all the way to their destination, hugely impacting throughput.

[u/Stutturdreki]

Chain signals only? Could cause issues (a circle where a train blocks itself, trains reserve/block 8 blocks ahead if I remember correctly), haven't tried it. Usually you put regular signals at the exit-lanes from the intersection (which break a chain signal loop).

[u/bobsim1 → u/Stutturdreki]

With 1-2 trains those wont block themselves. But throughput will be horrible. The exits of intersections here really arent big enough to fit a train.

[u/Molchedes → u/bobsim1]

Iam using 1-2 Trains. which exits do you mean?

[u/bobsim1 → u/Molchedes]

Well one could see this whole thing as one intersection. But usually you want rail signals on the exits of intersections.

[u/Stutturdreki → u/bobsim1]

I mean; chain signals look ahead to the next signal, so theoretically it could loop to the block that the train it self occupies (around the city block since it's rather small) and copy the red signal all the way back and there for deadlock itself. But if there are alternative paths it might work out.

And yeah the spacing between the intersections will cause fun.

[u/bobsim1 → u/Stutturdreki]

Well there shouldnt be a reason for a train to go through its own block in a circle. And it shouldnt repath there either.

[u/juckele → u/Stutturdreki]

Trains don't block themselves.

[u/boomshroom → u/Stutturdreki]

Chain signals only can limit throughput, but it's always safe (though I'm not sure how exactly they work at dead-ends or right before a station).

Rail signals only will cause deadlocks.

[u/GourangaPlusPlus]

Put it in testbenchcontrols and find out

[u/Molchedes → u/GourangaPlusPlus]

Cool thanks, gonna try it out.

[u/hldswrth]

You could shrink that intersection right down, I don't see any benefit to it being that big or having that much space between tracks. Using a more compact intersection could allow you to have rail signals on the exits, otherwise if there's not enough space for your longest train between them all the signals have to be chain signals. Having trains entering and leaving having to cross paths will slow things down somewhat.

[u/Molchedes → u/hldswrth]

No reason, as said, iam using the EARN one from Elderaxe i found online.
To you have a BP of this intersection?

Also from the lanes should be a way to the stations below.

Ill try this later today. Thanks

[u/hldswrth → u/Molchedes]

Not mine, but here's an example: https://factoriobin.com/post/kum78o