[0.8.8] mining output on conveyor T leads to traffic jam

[sparr]

In the attached screenshot I have conveyors in a T junction, combing east+west into northbound traffic. A mine is injecting ore from the south side of the T. When ore from the west (and only the west) hits the T at exactly the same time as the ore from the south, there is a jam. You can see an example about 3 tiles north of the T in this screenshot, where there is an ore in the middle of the conveyor and one off the left edge. Those two ore and all the other ore in the left lane move at half speed, while ore in the right lane passes them by.

If this sort of jam is meant to be annoying, then it's a bug that it only happens in one direction or from one side..

If not, then the whole jam situation is a bug.

[BurnHard]

Had been discussed already a few times, conclusion always was: "Difficult to fix, just don't build it that way"

[ssilk]

Every item is 0.28 tiles wide, so there is space for a "third lane", if two other items are pressed to the third in the middle. The outer item is then pressed to the border of the belt, which slows them down. It would be a ground laying change in the belt physics to remove this behavior - not to mention how this change can look, because it is just physics.

I mean, it is not a game problem, I think it's a documentation problem.

[sparr]

I'm not bothered by the existence of a third lane.

Should the third item jam the conveyor? If so, why does it only ever jam on the left side? (I suspect emergent behavior due to alignment/rounding)

[immibis]

You used to be able to send items down the middle of a conveyor, then they made it so the items snap to the left or top side. I don't know why they did that, but it explains why it only happens with the left or top side.

[ssilk]

For miners: left. For inserters it depends on their rotation. Rotation changes, when the inserter tries to fetch things on belts, which nearly drove out out reach. Can also happen, if you rebuilt something, or if you repair destroyed stuff.

The whole stuff is much better understandable, if you turn on the collision boxes in the debug mode and turn game speed to 0.3 or so.

In combination with turns, especially 180 degree turns, this will lead to blocking belts, the item is turned out of the belt, stops and blocks all following.

For me, as edited above, it's not a bug. It's some kind of layout or situation, which should be avoided. That must be learned, can be documented.

But from the game I await here a bit more help. A notice, that a belt blocks, a blinking warning, if a item on belt and item on ground are touching for more than some dozen seconds.