Factorio Forums

I have one chain signal that wont work where it is placed I was hoping some one could explain to me why its not working where I placed it.

I think you're using them incorrectly, My impression was that they are used when there are multiple paths the train may take, so they would be placed at the entrance to a junction only

I think you reversed the usage of normal signals and chain signals. A chain signal is used to prevent a train from entering a block it can't clear, so they should be on the outer parts of the junction, with normal signals on the inner parts.

As to why this specific chain signal is red - beats me... maybe a bug?

As far as I can tell it's correct and should work as intended.
Or almost as intended - exit signals from junction should also be chain ones. You use normal signals only in places where you want the train to wait potentially.
So in theory first normal signal would be after the junction where train can stop and stay since it cleared junction and won't block anything.

Thats the OpenTTD way at least - didn't have any experience here yet.

Post a save for devs to take a look maybe.

No, I think exit signals should definitely be normal signals - you don't want a train to wait if it's already inside the junction.

sillyfly wrote:No, I think exit signals should definitely be normal signals - you don't want a train to wait if it's already inside the junction.

You are right. Chain should look forward and only let through if that signal is green.

orzelek wrote:

sillyfly wrote:No, I think exit signals should definitely be normal signals - you don't want a train to wait if it's already inside the junction.

You are right. Chain should look forward and only let through if that signal is green.

it's the entry+internal signals that must be chain signals

ratchetfreak wrote:it's the entry+internal signals that must be chain signals

This is correct. You really only need three chain signals in a well constructed T junction though - one for each path that requires crossing over other tracks. Here's an example:



There's no reason to separate the three crossing tracks (forming a triangle in your screenshot, and an asterisk in mine) into multiple blocks, because a train passing through that crossing WILL block the way through all of them, guaranteed. So a single central block for crossing traffic is all that's needed. Similarly, you don't need additional signals before the splitting and after the merging at the entrance/exits to the intersection.

As for the signal that's blinking, the track it's attached to overlaps another track and the blocks are merged. For some reason, it no longer lists what blocks lead into and out of a signal on the right side info panel anymore, and I can't find a debug option that turns that information back on. It was really helpful in diagnosing problems like this, so I hope it comes back in some form.

Tallinu wrote:

ratchetfreak wrote:it's the entry+internal signals that must be chain signals

This is correct. You really only need three chain signals in a well constructed T junction though - one for each path that requires crossing over other tracks. Here's an example:



There's no reason to separate the three crossing tracks (forming a triangle in your screenshot, and an asterisk in mine) into multiple blocks, because a train passing through that crossing WILL block the way through all of them, guaranteed. So a single central block for crossing traffic is all that's needed. Similarly, you don't need additional signals before the splitting and after the merging at the entrance/exits to the intersection.

As for the signal that's blinking, the track it's attached to overlaps another track and the blocks are merged. For some reason, it no longer lists what blocks lead into and out of a signal on the right side info panel anymore, and I can't find a debug option that turns that information back on. It was really helpful in diagnosing problems like this, so I hope it comes back in some form.

Thanks for the picture and explanation that makes sense to me why that signal was not working. I was just playing around with signals and the like with the new 0.12 and it was confusing me why that signal was not working defiantly going to steal you design in a my new game though. It is much tidier.