Factorio Forums

Sometimes I've found all my trains in the central base jammed - nothing moving. One train has a path planned through a signal, that signal is yellow, but the train isn't moving.
To get things moving again, you can:
- place/remove a rail - anywhere on the map
- use the train timetable to restart this train

I've managed to reproduce this issue from an autosave. About 40 seconds after loading this save, the coal train will pull out of the station just NE of the player, and after another train passes in front of it on the lake loop the coal train fails to restart.

With what version of the game was the map originally created?

WIth 0.13.0, or possibly 0.13.1/.2.

Thanks for the report,

I can confirm this behaviour, it has something to do with the signal connection i believe

I've seen the problem occur at other signals on the map too, without any circuit connections.

jonatkins wrote:I've seen the problem occur at other signals on the map too, without any circuit connections.

Ok

I've had this too. Map and junctions created on 0.12 and migrated to 0.13. I have a game save with trains in this state that I can reload at will.

For me it was always the same blueprint of a 2-lane, Left-hand-drive T junction. One of the exits repeatedly jammed up in multiple locations on the map.

I moved the exit signal one rail further away and haven't seen the problem since. At the point the curve and straight rails meet, with a signal in hand, I had the signal on the 3rd green box on the outbound side. Since moving to the 5th box I haven't seen the problem.

In the image below, the yellow signal is in front of the train and you can see the green to the right. The merge section (block 978) has a train count of 1, the outward block (2) has zero trains. Yes, the yellow signal is definitely after the junction.

Just a quick confirmation the issue still occurs in 0.13.9 - the attached save should still reproduce it.

Also, I've not been able to see any pattern to the issue. Usually it happens at junctions, but I've found stuck trains once or twice on plain lines.

The only common factor I've seen is it always seems to happen in high traffic areas of the rail network - many trains travelling close together, high density of signals, short blocks - but that could just be because more trains there increase the odds of it happening there.

I've had this happen to me multiple times in the last half hour. Some observations:

• It's always happened with signals on or in close proximity to curves, or when the train itself was on a curve. I have not ever caught the stuck trains on a purely straight stretch.
  
  It's always happened in congested areas.
  
  I have not caught it in the act yet due to poor reaction time on my part to catch a useful autosave, but my gut feeling is that it is likely that it's a missed "resume" signal. ie: train stops behind another, train ahead starts moving, train behind (on the curved rail) gets messed up due to the curve mechanics.
  
  I'm still seeing trains coming to a complete stop and restart for no apparent reason in open, uncongested lines with nothing else even on the rails ahead of them. When I see a train following another train at high speed, I see the yellow braking-distance trace following along behind the red blocks of the train ahead. At some point the yellow trace stops advancing and the leading train just pulls away while the train behind does a complete stop-and-go at a orange->green signal.
  
  Changing *anything* related to the rail network (eg: adding a signal somewhere else, adding a station somewhere else) will instantly unjam it.

After seeing the latest FFF saying a stable release was planned soon, I'd just like to remind you this is still an issue in 0.13.10.

It's not a rare issue either - it happens perhaps once an hour or so in my current game.

Is anyone able to reproduce this issue with a fresh save on 0.13.9/0.13.10?

If you migrated a save from 0.12 through the early versions of 0.13 there's a good chance your map is simply in a bad state because of bugs already fixed.

The map was started in 0.13 (early - .0/.1 probably). Would "bad state" still apply?

The save attached to the original report still reproduces the issue - can you tell from that if it's in a bad state?

I will start a new map now in 0.13.10 and see if it still occurs. However, although the issue is common, seeing it happen is rare - I usually spot it a while later, once trains have backed up throughout the base.

I started a new game in 0.13.10, and have been playing it a while now.

The new rail network isn't as congested as my previous game, but I've just found a train stalled at a yellow signal again.
Unfortunately I haven't caught an autosave that reproduces the issue, but will keep an eye out for it again.

And again I've caught this issue on this map, shortly after updating to 0.13.14
Managed to catch an autosave of this one, a couple of minutes before it occurs.

The 100MB+ save seems a bit large to attach here, so I've put it on my website:

http://www.jonatkins.com/factorio/bugs/ ... tall-0.13/

Load the 'before' save, and wait a minute or two.

Spotted a third instance of this bug in this game (started in 0.13.10), but didn't catch an autosave before it happened.

Of course, it could be happening other times too, but as I'm often out of the main base extending the rail network the rail building is clearing the problem before I see it.

EDIT: Immediately after posting this, it happened for a fourth time.

I'm still seeing this issue after upgrading to 0.13.17, so it's not solved yet. This is in my game started in version 0.13.10

However, the the save game I linked to earlier, a couple of minutes before the problem, no longer reproduces it - something must have changed the timing slightly and it no longer happens from that save. The first save though, from the game started in 0.13.0, does still reproduce it.

Is that save still useful in diagnosing the issue, or should I try and catch another instance before it happens?

I can confirm that this bug still exists alive and well as of 13.17. I've noticed that once it happens, the SAME signal will continue to cause issues until I remove it. Puling it and putting it back down does not clear this repeating failure state.

See here as well: viewtopic.php?f=182&t=31508

I noticed that in all the cases the signal was just behind a curved rail

Still occurs in the 'stable' 0.13.19
Given the number of views on this bug report it's probably a common issue, but most people aren't seeing the need to comment.

No comments from devs for a month now - would be nice to know if it's been looked into, or if more examples were needed.