Factorio Forums

What did I do:
I set up a new plastic factory, using a blueprint from an existing factory.
I started up the trains to deliver coal and petroleum gas.
The top tanks provide gas to one set of chemical plants creating plastic;
the bottom tanks serve a second column.

What happened:
The top tanks have filled up, as the first column is now backlogged with plastic waiting for me to set up the next red circuit factory.
The bottom tanks are empty, and the second column is waiting for petroleum gas.
However, the fluid tank still contains petroleum gas, just under 10K worth.
Everything has power, the pumps are set to unload the tank, but they are not operating. I tried manually instructing the train to go reload with petroleum gas, but even when it is completely full, the bottom tanks remain empty. They are brand new, they have not been used for any other liquid.

What I expected:
I expected the train to unload petroleum gas from the fluid wagon into the bottom tanks.
Here is the blueprint for the train unloading station in the picture: Copy blueprint

I've experienced this sort of behavior before too. But was able to get it to work by trying the other positions (you have 6 on each side). For pumps, half of the 6 positions only seem to work. I used to be concerned but after being satisfied with one pump working I moved on.

An easy fix is to not leave the decision where to unload to the game. Just use three pumps on one side of the rails to get the petroleum gas out of the wagon. According to the wiki, this is the maximum number anyways. Then, use underground pipes (possibly with a circuit-controlled pump) to feed petroleum into the storage tanks on the other side of the rails. Why do you need storage tanks on both sides of the rails in the first place?

Each tank can only have one pump connection, the top and bottom pumps target the same tanks so this can not work.

I love factorio! I had missed the limit of 3 pumps per fluid wagon. I am curious as the factory that I copied from is working - one of the top pumps and the two bottom ones are both operating. As for why I had tanks both top and bottom, if I recall I was hoping to maximize unloading speed. Thanks all!

Amarula wrote: Fri Mar 13, 2020 10:09 pm if I recall I was hoping to maximize unloading speed

Pumps are so ridiculously fast that this is hardly necessary. If you go pump -> tank without pipes inbetween you've already optimized most of it:

https://gfycat.com/linedhospitablegroundhog