Factorio Forums

Be very careful when renaming stations, there may just be a train somewhere that makes deadlocking decisions.

The trains current destination was Iron, which is west.

What I surmise happened is that while the train was going south to west in the roundabout, I placed a same name station up north. It rerouted, but then I removed the stop while the train was in the south west block and beyond the junction. It decided to go west again but was blocking itself.

I wonder if it's possible to get around this edge-case without making a bigger roundabout

It is. No roundabouts, at all viewtopic.php?f=194&t=41486 I have explained my own quite intuitve railway setup, you might wanna take a look.

JackGruff wrote:[I wonder if it's possible to get around this edge-case without making a bigger roundabout

R
Increasing the roundabout size will not fix this.
viewtopic.php?f=41&t=26409#p232819

Removing the chain signals from inside the roundabout does. Just make sure none of your trains are longer than the size of the roundabout:
https://gfycat.com/PlainGoodnaturedAlpi ... igerbeetle

This is a more generalized problem which can affect other intersections types as well:
https://gfycat.com/JaggedAmusingAzurevasesponge
https://gfycat.com/GrandPoorGoshawk

Yeah, you have to get rid of the signals on the loop. This is the roundabout that I use. The bypass tracks here aren't needed to avoid deadlocks, they're just for speed:

reallyLost wrote:Yeah, you have to get rid of the signals on the loop. This is the roundabout that I use. The bypass tracks here aren't needed to avoid deadlocks, they're just for speed:

And I was hoping the inner signals being chains would avoid the need to get rid of them, which is what I read somewhere that's what they were good for in a roundabout. Could I please get a blueprint string for your intersection, btw?

Could make the roundabout bigger and use standard signals not chain signals.

- If the distance between each signal is large enough to hold a train and they separate the roundabout into 4 sections at a minimum, then trains wont bottleneck plus more then 1 train can go through it at a time. More of an oval then a 'round'about. But is the same principal, the long train is my construction train, my automated trains are 1 engine with 4 cars. Those loops are large enough to hold 2 small trains or even the long train without blocking the main straight lines.

- if the roundabout is divided into enough sections so multiple trains can't occupy enough sections to occupy all sections of the roundabout (depending on your layout and where the trains may go), they wont bottleneck. Not exactly as I described, but remove a car from that train and add signals to the lower half and it will be. This also plays into the layout remark. My factory was to the west, an outpost was to the north, other outposts were to the east. Trains will only go east <-> west or from the left side to the north and back. Think I had a few dozen trains use this roundabout since it was the closest to the factory and there were never any bottlenecks. Even if a train tried to u-turn due to accidental station naming, it wont block itself because they are regular signals, not chain signals.