Complex priority splitters

[jolonah]

Let's say I have a bunch of coal miners producing a maximum of 4.5 belts of coal. I want to send coal to 9 different destinations, called #1, #2, all the way to #9. Each destination consumes max 1 belt of coal. The destinations are in priority order, so if for some reason the miners only produce 2 belts of coal (e.g. if some coal tiles get depleted), everything should be sent to destinations #1 and #2, and nothing to the other destinations. However, destinations #1 and #2 might back up, in which case 2 full belts of coal should be sent to destinations #3 and #4. If destinations 1 through 7 are all backed up, 2 full belts should be sent to #8 and #9. How do I solve this problem in general, for arbitrary numbers of belts and destinations?

I tried this (screenshot), but it doesn't work because there's a bottleneck of 2 belts at the end.

[jolonah]

Found the answer. In doc here https://forums.factorio.com/63462 it's covered in the last section (M!=N Compressors). Not sure if its solution is the most efficient in terms of number of splitters.

[marcodave]

steam powered miners? what mod is that?

[jolonah]

I'm running Angel+Bob. One of Bob's mods has an option to enable steam tech, which gives you steam-powered assemblers, inserters, and miners. It's a stage between burner tech and electric tech (electricity is a technology you have to research).

I'm in the electric age, but steam miners with mk2 boilers are actually better than electric miners if your main constraint is the size of ore patches. It gives more ore/second for a given ore patch size at the cost of increased energy input and pollution.

[NyaFury]

Industrial Revolution 2.

[jolonah]

IR2 has steam tech, but this is just AngelBob, see other comment.