Factorio Forums

Situation:
Locomotive waiting at signal before stacker of 2+ lanes with all lanes full.
Issue:
When a path through the stacker becomes clear the locomotive will proceed instantly if it was waiting at a Rail Signal, but will have a variable but significant delay if waiting at a Chain Signal.
The locomotive should behave the same regardless of which type of signal.

To Test:
In the attached save file: with the locomotive set to Automatic, remove/replace the cargo wagons to test different paths.
Toggle "Close Signal" on the connected Rail signal to compare behavior of signal types.

Details:
The shortest path through the stacker resolves instantly in the vast majority of cases, but not always. For any other path the locomotive will wait at the now-open signal for a few seconds. The usual wait is 3-4 seconds but I've seen it range anywhere from 0 all the way up to 15 on even slightly more complicated setups.
In very rare cases the locomotive will only proceed once all paths (or maybe just that shortest path?) are clear. Unable to purposefully reproduce this case.

For testing the different types of signals I have a Rail signal immediately before the Chain signal that is connected and set to be closed whenever the Chain signal is closed (Red == 1). When at a Rail signal the locomotive will move as soon as a path clears regardless of which path it is.

Thanks for the report however that's working as intended: When a train is waiting at a normal rail signal it can only ever go through that 1 rail signal so it turning green causes it to go forward. When a train is waiting at a chain signal it's waiting for a specific path through the chain signal to o pen up and if one that *isn't* that path opens up it won't immediately take that path but instead periodically re-path as it waits at the signal.

If you open up the real path the t rain is waiting on it will immediately continue.