Round about dead lock with 30 trains

[warzouz]

Hi,

I've a quite advanced game with a lot of trains using double rail tracks and round about (12 of them on the network)

That went well until I've too much trains for my network, I've 30 trains now.

Trains get locked on round about every 15 min . Here is my default layout.

Can you help me fix the round about setting ?, thx

[Loewchen]

Remove the chain signals in the N, E, S and W position. If you want more throughput, do not use roundabouts.

[Bauer]

The locked train "though" at some point that going to a non-south direction would be the best path. Then it changed its mind while being in the roundabout.
Solutions:
- As Löwchen pointed out already: Avoid roundabouts.
- Design you train network such that every path from A to B is nonambiguous.

Re second proposal: Probably the problem is that you have a big circuit around your base. Make it a very big roundabout. Also use 2-headed trains and use dead-end stations only.

[warzouz]

OK, that's a huge undertaking.m

I played Factorio for few years but I never really went farther than the rocket. May base can handle sending rocket every 10min (maybe a bit faster). I'm increasing the base to alow researching AND sending rocket. The trains are using empty/full conditions so they shouldn't driver around too much, but when something is wrong (resource patch shutting down) trains starts spinning.

At that moment, there is a increase in train circulation and lock appear.

I'm working on reducing train rotation bu forcing a delay even if empty/full.

[DaveMcW]

Roundabouts with internal chain signals are not safe. This is a known bug.

No-signal roundabouts work fine, except they don't have very good throughput.

[Koub]

You may want to look at this topic.
It is a huge compendium of different railway intersections, tested for throughput and deadlockability.
Seeing your roundabout, you should search "2-lane" in the OP.

[imTheSupremeOne]

Wow! 30 trains... Btw how do u enable all that arrows on the track, and what they are showing?

[Loewchen]

Wow! 30 trains... Btw how do u enable all that arrows on the track, and what they are showing?

Chosen path of the train. Hover cursor above locomotive.

[warzouz]

31 trains now. Trains are 2 wagons (very few are 1 wagon)

I've solved my problem by removing my refuel station and adding roboports all over core base. The problem was when trains can't go to unload, they skip it and go to refuel then come back to load. The train traffic double or triple.

As I removed the refuel area for most trains, they stay on their loading stop when no unloading is available.