so, train unloading stations. like proably everybody else i had the problem that just using a staight belt and a bunch of injectors will unload the wagons one after the other with greatly increases the unloading time. using one belt line per wagon instead of the whole train improves things, but even then usually one wagon will unload much faster then the others witch makes the train configuration awkward. either wait forever untill the train is empty, or waste a good part of the capacity and limit the train to a single item type per wagon.
now it is rather easy to use the circuit network to make all the injectors work syncronized. however, this too was unsatisfying to me, even with one belt line per wagon. the problem with syncronized injectors is, that tho it unloads the wagons evenly, it will just syncronize the throughput of every wagon to the throughput of the wagon with the slowest line.
anyway, after a lot of experimentation i learned that if the unlaoding station is build right, it does not even need circuits to unload all wagons balanced at full speed (or, if the demand is lower then the supply, every wagon at 1/4 of the demand).
i came up with two versions, one for a 4 lane output and one for a 8 lande output.
4 belt output:
8 belt output: