Factorio Forums

While manually upgrading the main bus, I came across a situation where one belt spills into another. The spill is rare and happens once per several hundred items.

The schematics are as follows:
Belt 1 and 2 are parallel and adjacent and contain different kinds of items. Belt 1 is yellow (slow) and belt 2 is red (fast). Both are almost full but not compressed.
At one tile, belt 1 enters underground (yellow underground), and on the next tile belt 2 widens into a splitter (red/fast splitter). The splitter occupies the space belt 1 would have used if it didn't go underground.
Both arms of the splitter get some items from belt 1 in this case, but very rarely.

The version I'm playing is 0.17.74.

What exactly are you considering the bug? That items can enter an underground belt from the side?

What Loewchen describes is a feature of underground belts detailed here:
https://wiki.factorio.com/Belt_transpor ... belt_lanes

amirlb wrote: ↑Fri Nov 15, 2019 1:35 am At one tile, belt 1 enters underground […]
Both arms of the splitter get some items from belt 1 in this case, but very rarely.

But it sounds like the items spill out of the underground in this case. Can you post a screenshot?

I revisited my previous saves on the same map, before and after the stray items appeared on the incorrect belt, and tried to reproduce both there and in a cheat map. Couldn't recreate it, so please consider this a false alarm.

There's no bug as far as I can tell.

Is there a proper way to close this report?