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No path for train in automatic mode, despite having signals

Posted: Sun Oct 01, 2017 7:26 am
by makapse
I was recently running a successful factory and suddenly, one of my train lines suddenly says that "no path" available for automatic mode, but it used to run normally before and there is no signal locking and I can run the route manually. Can anyone please tell what is causing this issue? Also, if someone points out how to attach the save game, I can also do that if needed.

Re: No path for train in automatic mode, despite having signals

Posted: Sun Oct 01, 2017 8:02 am
by Kyralessa
There can be several reasons to get a "no path" message:
  • Your train doesn't have a locomotive facing the correct direction.
  • There's a break in the track between your locomotive and your destination.
  • The signals are placed incorrectly.
If you're completely stumped, manually move the train a bit along your expected path, then switch it to automatic again. Keep doing this, and at some point you'll get to where the "no path" message goes away. Then at least you've narrowed down where the problem is.

If the problem is signaling, try removing signals until the problem goes away. If you remove too many, the worst that can happen is you'll get a couple of damaged locomotives which you can easily repair. Once you've removed enough signals that there's a path again, you can see whether you need to add any back.

Re: No path for train in automatic mode, despite having signals

Posted: Sun Oct 01, 2017 9:42 am
by Engimage
I would say most of times "No path" is a result of misplaced signals.
And most common issue is marking a rail fragment "one way only" while it should really be 2-way. You got to remember that if you place a signal without its counterpart on another side of the rail this particular spot will be one way only so if you need to place such signals, say you need a chain signal before intersection, then you absolutely need to put its counterpart if you want trains to move both ways here. Counterpart signal may differ from original so you might have chain signal one way and normal backwards.

And yes, check if your train has a locomotive facing correct way. If you want a train move both ways (Terminus stations) you need locomotives facing both ways in your train. Trains can not reverse in auto mode.

Re: No path for train in automatic mode, despite having signals

Posted: Sun Oct 01, 2017 10:23 am
by Loewchen
makapse wrote: if someone points out how to attach the save game, I can also do that if needed.
Post reply -> Upload attachment in the bottom left.

Re: No path for train in automatic mode, despite having signals

Posted: Sun Oct 01, 2017 6:08 pm
by makapse
I will post the save file tonight when I am on a better net. The file does'nt want to be uploaded on my crappy mobile net. No mods installed. I just deleted a section of the track and rebuilt it. The problem started after that.
And the route used to run earlier. I can still run it manually. and moving it doesn't matter at all

Re: No path for train in automatic mode, despite having signals

Posted: Mon Oct 02, 2017 7:20 am
by makapse
Please find the attached save file. The train route is second iron pickup to iron drop.

Re: No path for train in automatic mode, despite having signals

Posted: Mon Oct 02, 2017 8:50 am
by impetus maximus
second iron pickup station doesn't seem to be valid.
notice when i mouse over it doesn't show where the engine, cargo wagons would be?
invalid.station.png
invalid.station.png (131.81 KiB) Viewed 182121 times
i moved it left 1 block and the train seems to work fine.

Re: No path for train in automatic mode, despite having signals

Posted: Mon Oct 02, 2017 9:43 am
by makapse
Thanks a lot.
I have no idea what caused this.

Re: No path for train in automatic mode, despite having signals

Posted: Mon Oct 02, 2017 10:08 am
by impetus maximus
no problem. if you place the stop, remove the track next to it, add the curve it no longer functions as a station.

Re: No path for train in automatic mode, despite having signals

Posted: Mon Oct 02, 2017 2:16 pm
by Jap2.0
Yep. Looks like you placed it on a straight piece of rail one tile past the beginning of your curve, then deleted that rail to make the curve, which starts on the tile of the train station (and train stations can't go on curves - even if they could, I doubt that it would line itself up if you changed the rail type)

Re: No path for train in automatic mode, despite having signals

Posted: Wed Apr 28, 2021 6:21 pm
by Aanokint
PacifyerGrey wrote:
Sun Oct 01, 2017 9:42 am
I would say most of times "No path" is a result of misplaced signals.
And most common issue is marking a rail fragment "one way only" while it should really be 2-way. You got to remember that if you place a signal without its counterpart on another side of the rail this particular spot will be one way only so if you need to place such signals, say you need a chain signal before intersection, then you absolutely need to put its counterpart if you want trains to move both ways here. Counterpart signal may differ from original so you might have chain signal one way and normal backwards.

And yes, check if your train has a locomotive facing correct way. If you want a train move both ways (Terminus stations) you need locomotives facing both ways in your train. Trains can not reverse in auto mode.
Years later and this message saved me! Just getting into trains after 150hours. After trouble shooting my rail, I now have three locomotives on one rail network with 7 destinations! Got my Trans-Factorio Express achievement too after I had it all set up properly! Thank you!

Re: No path for train in automatic mode, despite having signals

Posted: Thu Jan 27, 2022 8:56 pm
by darkben7
PacifyerGrey wrote:
Sun Oct 01, 2017 9:42 am
I would say most of times "No path" is a result of misplaced signals.
And most common issue is marking a rail fragment "one way only" while it should really be 2-way. You got to remember that if you place a signal without its counterpart on another side of the rail this particular spot will be one way only so if you need to place such signals, say you need a chain signal before intersection, then you absolutely need to put its counterpart if you want trains to move both ways here. Counterpart signal may differ from original so you might have chain signal one way and normal backwards.

And yes, check if your train has a locomotive facing correct way. If you want a train move both ways (Terminus stations) you need locomotives facing both ways in your train. Trains can not reverse in auto mode.
Five years later, thanks man!