Thrusters activate in odd pattern [2.0.76]

[coffee-factorio]

What I did:
Placed thrusters in a row using remote view in the map editor. Attached infinity pipes so they had fluid. Fired a short thruster burst towards Gleba.

Following up on a rumor from reddit, found the thrusters distribute fluid in an inconsistent pattern.
Common logic indicates that you shouldn't be able to connect thrusters like this. In fact, the map editor will refuse to construct thrusters like this while remote view allows it.

What happened:

Thrusters fired in an odd activation pattern. Pun intended.

Showing odd pattern

Screenshot 2026-02-28 031117.png (1.97 MiB) Viewed 190 times

Attempt to add thruster in map editor

Screenshot 2026-02-28 033742.png (2.03 MiB) Viewed 190 times

Result in remote view

Screenshot 2026-02-28 033821.png (2.27 MiB) Viewed 190 times

Result in flight

Screenshot 2026-02-28 033929.png (1.79 MiB) Viewed 190 times

Save attached.

I would expect:

Either all the thrusters fire, or none of them fire. Use your best judgement.
For the UI to consistently allow or disallow construction between the the map editor and the remote view.
Very much edge case performance.


Does it happen always, once or sometimes:
Tested with infinity pipes to see if the issue changed with connection. It does not. Also tested out if adding pipes on one end or another changes things.
That was neat: I flooded an infinity pipe that's supposed to be filled with oxider with fuel.
As a note, the rumor on reddit had all thrusters firing. It's possible someone manipulated the image or my memory is off. But this is what I'm seeing on my system.


Appears to be related to this post:
viewtopic.php?p=662626&hilit=thrusters#p662626

[boskid]

I am not seeing any bugs here. Thrusters have pipe connections across diagonals so first thruster gets fuel on top left pipe and oxidizer on bottom left which is correct. Second thruster sees oxidizer on the top left input which is wrong fluid and fuel on the bottom left input which is also wrong fluid and as such thruster does not work. Second thruster swaps fluids for third thruster which again works.

-- edit:

This exact scenario will not work in 2.1 due to mixed fluids.

[coffee-factorio]

May as well as call it fixed in 2.1 since at that point "none of the thrusters will swap fluid".

The only thing left is the inconsistent behavior between the map editor (I can't place thrusters) and remote view (I can). Seems like a debatable edge case, I'm not taking it too seriously. Thanks for the attention, have a good day.

[Nidan]

The only thing left is the inconsistent behavior between the map editor (I can't place thrusters) and remote view (I can).

From what I recall from the attempt of eradicating fluid mixing during 1.x (or was it still 0.18 at that point?), this is intentional. There always was some corner case resulting in fluids mixing and after fixing that one, someone used that fix to find a new corner case. In the end, the decision was to disallow mixing when building manually while not interfering with blueprints/ghosts (which includes remote view).

[Tertius]

This exact scenario will not work in 2.1 due to mixed fluids.

Does that in 2.1 mixed fluids is possible, or does that mean in 2.1 the fluid system is better protected against (accidental) mixing of fluids? Bidirectional fluid boxes are not as isolated as they should be, as far as I remember.