How To Set Up And Use A Main Bus Design In Factorio

As you grow your factory in Factorio, you may have trouble keeping all of your resources organized, especially if you’re prone to developing spaghetti factories. Rushing to the next tier of Science often causes these issues, as you build only what’s necessary at the moment, leaving little room for future expansion without a full teardown.

Luckily, there is a simple solution to this problem that can greatly help with organizing your factory: the main bus. This structure is essentially a never-ending line of Belts that carries almost every item you may need, letting you sprout off smaller factories to the side to refine these items into more complex components. Below, we’ll take a look at how to build and take advantage of a main bus.

What Is A Main Bus?

A main bus is a series of belt lines that contain basic items that are used in most recipes in the game. Your main bus can either extend vertically or horizontally, but there’s no functional difference between the two beyond personal preference.

The advantages of using a main bus include helping you stay organized, creating a central flow of materials, while also being easily expandable by simply extending the bus further. However, main buses take a lot more belts than other factory structures, and it can take a while to get from the start to the end of the bus in developed factories without the use of vehicles or trains.

How To Set Up A Main Bus

Before you start building your main bus, scout out a suitable area. You’ll want to find a location that will let you build in a straight line uninterrupted for a long distance, so avoid building into lakes or cliffs if you can help it.

If you do run into a lake, you can use Landfill to cover it up and keep building.

Once you’ve found a good location, all you have to do is start building your belts in a straight line. Typically, main buses are built in four-column blocks at a time, with each block of four belt columns carrying one type of item. This isn’t a strict rule, however, and sometimes you may only have need for one or two belts per block and item type.

The reason for keeping blocks in four-column blocks is so that an underground belt can pass between them.

Another thing to consider is what items you want your main bus to carry. Typically, you’ll want to have a few four-column blocks of the basics: iron plates, copper plates, and steel. From there, a few common additions are iron gear wheels, electronic and advanced circuits, steel plates, processing units, batteries, plastic bars, stone, and sulfur.

When adding materials into your main bus, be sure to use a belt balancer near the beginning so that all four belt lines are equally saturated.

The best part about using a main bus is that it is easily expandable, so you can really add any item that may be useful in multiple places throughout your factory.

How To Draw From A Main Bus

When it comes time to actually use the materials in your main bus, you’ll want to be careful that you don’t leave the rest of the belt column under-saturated. To do this, you’ll want to balance the belt as you create a fork for the departing material.

There are a few different ways to accomplish this, but the easiest is to simply re-balance the belt after you take from one column, using a standard four-column balancer. This will keep the main bus from running out of materials later down the line.

You’ll also want to ensure that your smaller factories that are using the main bus’s materials aren’t drawing more materials than are necessary for that factory, as this can cause bottlenecks and throughput issues later in the bus. Always keep in mind ratios and throughput requirements when splitting off a section of your main bus.