メインバス(Main Bus)の概念は、組立機で最も利用され、また利用価値のある原料を中核に据えるもの。 これにより構造化された配置が強制され、利用するアイテム全てをバスから引っ張り出すしかなくなるため、「スパゲッティ工場」と格闘する良い手段となる。 これらは同時に欠点でもあり、より多くのベルトを使用するし、よってベルトのバッファにより多くのスペースを使用するのでコンパクトさからは程遠い。
バスはよく、鉄、銅、鋼の精錬から始まり、時間と距離が離れるほどにより多くの異なったアイテムを含むようになる。 ベルト(分岐先があればそれも)が飽和するほどの生産量を確保できない場合、飽和しないそれらは「偽」バス("fake"-bus)と呼ばれる。 特に、アイテムが止まってしまい、ベルトが一見運べそうに見えるだけの量を運べないせいで全てのベルトがいっぱいになっている場合は騙されやすい。 後の拡張に備えた空間のせいでこうなることもある。この場合ブループリントの仮設置が便利で、ベルトが利用不能なアイテムで一杯になることを防げる。
バスの方向が垂直か水平かは個人の好みで、十中八九後から利用拡大のために拡張することとなるだろう、分かれた生産部をどう動かすかによる。 向きごとにプレイヤーが監視できる幅もまた、この決定に影響する。 曲がり角の存在が許されないわけではないが、殆ど見られない。大概の場合、予定外の池が出てきたときくらいにしか使わないだろう。
What items one puts on a bus is personal preference. Some items are a good candidate to be built "on-site" meaning not carried by the bus but rather made where they are needed. A good example for this are copper cables as they consume more space on a belt than in form of copper plates.
Here are some things people have put on their bus in the past:
- Several belts of Iron plates, usually a multiple of four as that is the length one underground belt can go underneath of.
- Some belts of Copper plates as well, usually less than Iron plates, as of 0.15 a lot less.
- Iron gear wheels are seen on some buses as of 0.15 as they're taking up half as much room than iron plates (are denser) and see usage in a lot of recipes.
- Electronic circuits and later on even
- Advanced circuits though that may not be necessary as they just get used up quickly in other steps and aren't used in that many different products.
- Steel plates.
- Processing units are rarely seen on a bus as they are used in even less recipes than the other mentioned intermediate products.
- Plastic bars (sometimes replaces coal from where plastic is produced).
Each of these Items would get a dedicated line of belts from which one would draw from if there is need for the item.
Some people like to have fluids part of their bus which could include:
Having all possible items on a bus results in a huge wide bus with a lot of belt-buffer for expensive items and standing belts of output-items that wont get used in another process. These items are often just put into chests for personal use rather than on a bus.
The width of the bus can become a problem if it is very wide. Players sometimes choose to only build on one side of the bus until they can estimate that they wont need more belts on the bus.
It is advisable to leave space between the groups of belts of one item for underground belt to surface and for other things to cross the bus. A recommended numbers is two free spaces for every group of four belts, although leaving more space can be useful too. Same with the production that is to the side of the bus, leave space between the builds for later expansion or belts that go between, at least three, six to ten is fitting. Grouping differing items together can cause problems when splitting them off, hence only groupings of two differing items is recommended. Having smaller groups of only one or two is also not a bad thing.
When logistic robots are available one might start moving some items by robots instead of using the bus. Some players eventually phase out the main bus entirely in favor of robots. This may happen at a later stage in the game up to which a bus is a very good tool to reduce clutter. But robots have their own difficulties and require a lot more resources and knowledge of the game.
For very large amounts of items railways may be a better alternative that can not only carry large amounts of ore but also the intermediate and end-products. This can lead to designs of a base consisting of only train-stations with small logistic networks without any belts. For a comparison of belt, logistic robot and railway transport systems, refer to the Transport use cases tutorial.
When one wants to use the items on their bus one could directly take items off the bus as if it is just a belt, though that would mean an extremely long bus and useless lengths of other belts. This is sometimes done to get Items crafted into a chest for personal use like pipe which only uses Iron plates. However in most cases a belt is split away from the main bus that can deliver the resource to the factory. Split-off designs aren't strictly necessary but help immensely. The following designs have the additional property that if the incoming belts are fully saturated then the split-off belt will be full (recall that a single splitter with a single full input belt will by default split off a half-filled belt).
With splitter priorities that were added in 0.16 it is very simple to split off a belt from a main bus while ensuring good throughput properties. The design shown here makes sure that the belts on the right side are filled first, so belts can be taken from the right every time without the need to further rebalance. Thus up to a full belt can be delivered and the remaining resources can go through on the main bus.
Alternatively, one can make split-off setups without priority splitters. The idea is that one wants to draw from every belt (and lane even) equally to not have too few items at the current planned production and not have empty and at the same time standing belts of items. That way at every step along the bus a few items are split off and used up and when the production comes to a stop the items go on to be used by the next production.
The following are 2 designs for a split-off off a 2-wide bus (by reddit user /u/unique_2).
Putting a lane-balancer after a split-off is not necessary most of the time as the rest moves on if the belt has no draw or if only one lane is used. If there is enough input for the item to saturate a whole belt then putting a lane-balancer in wont help to get more items later on. Putting a lane-balancer after an inherently balanced build that produces the item is also not necessary as then half of the production pauses and the other half fills the moving lane to saturation. The following is a split-off off a 4-wide bus.
Taking two belts off of this wont produce two belts worth of output, the middle one only carries half a belt to each side! As of 0.16 Splitters can prioritize one in- and output lane, therefore the above design can supply fully saturated belts, if the splitters are set up in a way that prioritizes the output belt (to earlier production) rather than letting items go on.
The following are two designs for a split-off off a 4-wide bus that feature an in-line lane-balancer(by reddit user /u/moomaka).
The way in which materials are split off from the main bus determines which production setups in the factory are prioritized if the bus delivers less input than all the setups combined need. The split-offs shown above generally prefer setups near the start of the main bus but will also supply some limited materials to the later setups. There are alternative designs, for example using splitter priorities on can fully prefer the setups near the start of the main bus and only allow materials to go through to a later setup if that earlier setup's needs are satisfied. The priorities can be set in various ways but this should not distract from the fact that more resource input should be added whenever this becomes a concern.