Having a nightmare with train signals

[wadson]

Hi,

Noob here in both Factorio and posting in forums. I'm absolutely loving this game, however I've run into bit of an issue with train signals and I would really appreciate any assistance I can get. I have completed the in game tutorials and messed about with trial and error - even watching YouTube tutorials and still can't figure out what I'm doing wrong . Things were going great until I added another train into the mix of my locomotive iron ore run and hoping some one could help me figure out what I'm doing wrong? Been at this trying to figure it out all morning haha. I'm trying to allow one train to be off loaded and then go off on the other track, which then allows the waiting to approach for it's off loading, with the same happening at the opposite end during loading. I've attached a couple of screenshot to help with what I mean. Hope you folks can help , this is the only issue I've struggled with so far. PS the damage to the trains is where they have crashed into each other during testing the signals out.

[SoShootMe]

Can't see any screenshots. Uploading a save might also be helpful.

[wadson]

Sorry about the screenshots not sure what happened there. I have hopefully uploaded the save file. Thank you for your response. Excuse the file name this was when my railway was actually working haha.

[wadson]

These are the screenshots that were originally meant to be attached. Its not the most ambitious rail network yet, but we have to start somewhere I suppose.

[Impatient]

Have you read this?

https://wiki.factorio.com/Tutorial:Train_signals

[Kyralessa]

The most basic rule of thumb, which will handle just about every signaling situation:

Use chain signals before shared track, and regular signals after shared track.

Have a look here:

https://wiki.factorio.com/Tutorial:Trai ... in_signals

Notice in the first picture how the track between the two trains is shared with track crossing it. That's where you use a chain signal, so you don't block the intersection while waiting.

In the second picture, it's the same way, with a few additional chain signals in the middle, but the basic principle is the same: Before entering the shared block, chain signal; after exiting the shared block, regular signal.

[SoShootMe]

Sorry about the screenshots not sure what happened there. I have hopefully uploaded the save file. Thank you for your response. Excuse the file name this was when my railway was actually working haha.

First of all, near "poorprogramming", the junction is broken. Looking from the south, the western line needs to start turning earlier to join up with the east-west track at the station.

Please do read the tutorial Impatient mentioned. A key comment in it is this:

Trains are only allowed to go past signals that are on the right hand side from direction of travel.

After fixing the junction, you can get your track working with just one signal at each end of each of the twin tracks, before they start to merge (four signals in total). Because of the quoted comment, twin track may be considered either left- or right-hand drive. Given your track, the latter makes sense, which means placing signals on the "outside" of the twin tracks:

poorprogramming.jpg (178.29 KiB) Viewed 2879 times

Martin Steffen.jpg (165.39 KiB) Viewed 2879 times

[Serenity]

Signals also indicate direction. At the beginning of the station rail piece where trains can go both ways place two signals exactly opposite each other. Then on the one-way track a signal on either side.

EDIT: with multiple trains going to one station you need a chain signal before the merge/split so that the train waits there and lets the train in the station out

[wadson]

Thank you all so much for the replies. I will definitely read the wiki tutorial thanks Impatient . SoShootMe, Serentity and Kyralessa thanks for your advice it makes a lot more sense now, and I'm sure once I've read/consulted the tutorial link things will become clearer for more complex routes/networks. EDIT:- That's me got it sorted now, I did exactly what you guys and the tutorial said and one train was running fine and the other was highlighting the error message, I could not work out what the issue was. I ended up deleting one of the stations from the train and re-entering it and all seems to be working now, strange. Again thanks so much for the help folks . EDIT number 2:- PLEASE MAKE SURE ALL YOU TRAINS ARE THE RIGHT WAY ROUND! What a dunce.

[SoShootMe]

Signals also indicate direction. At the beginning of the station rail piece where trains can go both ways place two signals exactly opposite each other. Then a the one-way track a signal on either side.

Signals on the bidirectional track sections aren't needed in wadson's case, because they are at the ends of the line. More importantly, if signals are placed on the bidirectional track, the signal on the twin track for a train heading to the station must be a chain signal, otherwise a train heading to the station may block a train in the station from leaving it (deadlock).

Typical signaling for a merge/split between bidirectional and unidirectional parts of a rail network, which makes a Y shape with "in", "out" and "in/out" rails, is to have signals on the "in" and "out" rails plus a pair on the "in/out" rail, with all being chain signals except for the "out" signal. However, the signal protecting (at the entrance to) a block containing a train stop should be a rail signal.

[Serenity]

I haven't checked what he built exactly, but if you don't have two signals somewhere making a track two-way you get a "no path" error. Either in or out depending on which one is missing.

The part about the chain signal is true. And he does use multiple trains per station. When I know that's the case the station gets a waiting area, which of course uses a chain signal. It's personal preference, but when you know that there is always only going one train to a station there is no need to take extra precautions. You just need to know what you're doing and what works for the current situation.

For an ore station you may want to plan ahead and prepare for multiple trains, but for things like a shuttle or building train I don't bother


Here are two stations on the left side both going to a shared station at the top (chain signal on the top before the entrance):

Trains.jpg (260.16 KiB) Viewed 2773 times

Also shows how to signal an intersection. Chain before a crossing and normal after. Normal signals before merges.

[SoShootMe]

I haven't checked what he built exactly, but if you don't have two signals somewhere making a track two-way you get a "no path" error. Either in or out depending on which one is missing.

The paired signals nearest each of the stops in your screenshot are not needed (it's the same situation as in wadson's screenshots). Look at the block containing the split/merge. Move the signals a little towards the end of the track and look again. Keep going... All you're doing is extending the bidirectional part between the paired signals and the split/merge point, and you can keep extending it until it reaches the end of the track.

Also, I think the rail signal opposite the chain signal near the east stop is redundant, as there's no way for a train to approach it heading north.

On closer inspection, with the signals as they are (without removing the pairs I mentioned above), the signals immediately before the pairs on the way to the lower stops should be chain signals (if you remove the pairs, they should be rail signals). For example, park a train at the west stop, drive the other train to the north stop, then send it to the west stop. Each train faces a red signal due to the other.