You don't need to have 2 trains parked simultaeneously. Since you draw of half the amount of items per train the buffer chests will last twice as long. So you only need top have a train at each station 50% of the time. Or argued differently: You have the same number of belts overall so the same number of trains are needed overall. But now the trains go to twice the number of stations. So half as many trains per station per minute.eradicator wrote:@mrvn:
This thread is not supposed to be a generic "good factory design" thread. It is supposed to focus on the task of unloading 2 belts per side for those who might be interested. In order to prevent further derailing (haha ) of the topic towards "but this is pointless!" i have edited the opening post and added an FAQ section which also addresses your question.
Regarding your "use more trains" idea: That does not work. If you e.g. use two trains with one belt per side each you now need to design a station to be able to constantly have two trains parked simultaeneously. Because if one of the stations is empty you lose one belt of throughput. The only gain you get is a slight increase in the time you need between two trains due to increased buffer sizes. But as you now also need twice as many trains and twice as many inserters+chests it is doubtful that you would gain much in terms of ease-of-throughput while significantly complicating your station. This is contrary to the point of making fewer stations by using high-speed unloading.
And if you have half the number of trains per minute you could use half the number of inserters and buffer chests to unload. But then you would be back where you started. The benefit of having twice the number of inserters and buffer chests to unload is that you unload twice as fast leaving more time for the trains to leave and the next to arrive without the belt going empty. Early on when you don't have maximum stack inserter bonus researched that can be a huge difference.