The railway scheme below is intended to be a train waiting line, where trains come from the right and also come from the left.
As it is, it works. But if I try to delete this chain signal:
then any train who comes from the right when there are trains coming from the left simply stops. This doesn't make sense to me, since the intermediate "exits" below are free. Why is this happening?
Chain signal doubt
Re: Chain signal doubt
What your chain signal does is mark the straight track between the junctions as one way from left to right.
Removing it turns that track into a two way. The pathfinder then prefers to go straight since each track and signal passed adds a penalty.
Removing it turns that track into a two way. The pathfinder then prefers to go straight since each track and signal passed adds a penalty.
My Mods: mods.factorio.com
Re: Chain signal doubt
What's with the left side Y junction? Make sure to have signals wrapping around every part of every junction. Make it a general purpose rule. It's for your benefit as much as it is for the trains.
Optera nailed it. The chain signal at the top causes the middle chunk to be a right way only track, while the left way only wraps around the lower path. Removing the signal restores the top path to a 2-way path. So the bottom path is left only while the top path is 2-way, this causes trains to mess up.
When building a train bypass, make sure that both directions have their own dedicated 1-way track.
Optera nailed it. The chain signal at the top causes the middle chunk to be a right way only track, while the left way only wraps around the lower path. Removing the signal restores the top path to a 2-way path. So the bottom path is left only while the top path is 2-way, this causes trains to mess up.
When building a train bypass, make sure that both directions have their own dedicated 1-way track.