Belt transport system

Transport belts(#1) move items, Splitters (#2) distribute the input onto both outputs 1:1, Underground belts (#3) are used to bypass obstacles.

The belt transport system is the first transport system available in Factorio, and together with Trains and Logistics Robots make up the backbone of any Factorio base. Transport belts (sometimes called conveyors) are used to transport Items. Belts don't need power for transportation. This is one of the many Mysteries of the Factorio World.

Beginner

Transport belts	Underground belts	Splitters	Max. throughput (Items per game-second)	Needed research
File:Basic-transport-belt.png Basic transport belt	File:Basic-transport-belt-to-ground.png Basic underground belt	File:Basic-splitter.png Basic splitter	13.393	Logistics 1
File:Fast-transport-belt.png Fast transport belt	File:Fast-transport-belt-to-ground.png Fast underground belt	File:Fast-splitter.png Fast splitter	26.786	Logistics 2
File:Express-transport-belt.png Express transport belt	File:Express-transport-belt-to-ground.png Express underground belt	File:Express-splitter.png Express splitter	40.179	Logistics 3

Transport belts move items. To take items from/put items onto a belt, use Inserters.

Differences between the belt tiers

The main difference between different tiers of belt is the speed at which they operate. As a belt is upgraded from yellow to red to blue, it gets faster and is able to move more items. The Physics page has some technical information on exact values for each tier of transport belt.

Merging and un-merging

Belts have two lanes that can be used for transporting. This allows for either a double flow of one material, or with some careful setup, transporting two different materials on the same belt. Mixed belts can be beneficial for smelting ore, or producing items with many different ingredients such as the science pack 3. Un-merging a mixed belt is fairly easy too, since an underground belt will block half of your belt. So there is no reason to be afraid of mixed belts at all.

   

Balancing belts

Sometimes one side of a belt will be more empty than the other. In this case, rebalancing the belt can be helpful.

The left design will only rebalance equally if one side of the belt is empty while the right version always balances equally.

   

Another example, including side balancing credit /u/Bhoedda from reddit

Advanced

Speed, Density and Throughput: About finding bottlenecks

Maximizing the throughput is important, since it will keep belts efficient. Therefore some definitions need to be introduced:

Speed

How fast does a belt move.

Density

How tight are the items put on the belts.

Throughput

This is speed * density. It describes how many items pass by in a given time.

So there are two opportunities to enhance the throughput:

More density

Sometimes items have little spaces next to each other that aren't big enough for other items to fit in. In this case reordering the items can still increase the density. This can be done by temporarily increasing the belt speed on a single tile or by merging 2 lanes with an inserter.

More speed

If the belts in the factory are already at maximum density, their speed can still be upgraded with better belts. Finding the bottleneck is the first thing that needs to be done, usually it can be discovered quite easily. There will be a part of the belt where the items don't move quickly (or at all) or stop at maximum density and suddenly they come to a point where this 'stop and go' effect releases itself, the bottleneck has been found. In most cases, this will be the place where belt optimization is needed.

Belts

Animation showing the three types of belt and their speed (from top to bottom: regular belts, fast belts and express belts).

Type	Max. throughput (Items per game-second)	Speed (Tiles per game-second)	Max. density (Items per tile)	Required technologies
File:Basic-transport-belt.png Basic transport belt	13.393*	1.875*	7.143*	none
File:Fast-transport-belt.png Fast transport belt	26.786*	3.750*	7.143*	Logistics 2
File:Express-transport-belt.png Express transport belt	40.179*	5.625*	7.143*	Logistics 3

 * experimental value: See Transport belt experiments for more detailed information.

Splitters

The behavior of splitters looks simple at first glance. But they are not that simple. Splitters have an astonishing amount of uses.

• splitters have two input-belt-sides and two output-belt-sides on which you can connect any belt or underground belt
• splitters don't shuffle the lanes on the belts; items on the left input belt lane don't change the side to the right lane (and vice versa).
• Splitting
  • if two output-belts are connected, then every input-item is put alternated on one of the two output-belts. Or in other words: it is guaranteed, that the inputed items are output in a ratio of 50% on each belt.
  • if one of the output belt lanes are full, then it tries to output on the other output belt. This is useful to fill belts.
  • a lot more details about the exact splitting can be found here http://www.factorioforums.com/forum/viewtopic.php?f=18&t=3765 and here http://www.factorioforums.com/forum/viewtopic.php?f=11&t=511&p=3019 !
• Joining
  File:T&T Belt04.jpg

  Feeding from side is only a good use, if you want to make a queue - e. g. for mines, some output-buffer
  File:T&T Belt03.jpg

  Better: The capacity of the output belt is fully used.
  • splitters can be used to join two belts into one. This has a much higher throughput than only side-inserting.
  • as with splitting, the belt lanes aren't mixed up.
  • Use faster splitter if you want to feed into a faster belt, because otherwise your splitter is the bottleneck!

Splitter prefers in most cases one input for joining

When both input belts are at full capacity, then the splitter prefers one input, or in other words: one input is only taken to fill gaps in the other input. This is not in all cases like so, see these tests, but the chances are high, that

• splitters pointing into north or west tend to prefer the right input
• splitters pointing into south or east direction prefer the left input.

The reason for this behavior is explained by the game developers:

"But there are fundamental problems with equal joining. How exactly will you define it?

Once you have available item to move to the belt on left belt, you would have to wait, if some other item on the right belt don't arrive, as it would be the time for the right belt to be activated.

But how long do you wait? And once you wait you limit the throughout of the splitter."

This behavior can be used to prioritize an item-source, for example a storage.

This is the current result: Joining with Splitters.

See about the whole story: Splitter priority when joining.

File:T&T Belt08.jpg

Left side: A splitter cascade to let only the unused items into the storage. Center: A simple storage. Right side: The splitter prefers taking the input of the upper (left) belt, so the input from the storage is lower priority.

Underground belts

File:Split-swap.png

You can turn the order of the lanes or split the lanes completely with the underground belts trick

Underground belts can be used to cross different flows of items without interfering. They move items like a normal belt.

• You can cross any number of entities and all types of ground, like water, swamps, etc. (input and output of course over water)
• You can cross other underground stuff (any number of underground belts or underground pipes). They won't be mixed.
• For the connection only the endpoints (entry-side and exit-side) are relevant.
• The maximum distance underground is 4 tiles.
• An underground belt pair with a blocked output stores up to 20 items. (Per lane? Untested!)
• If you mine an underground belt, up to 20 items are recovered, the remaining items in the underground are placed into your inventory.
• The half of the underground belt tile with a belt can accept input from the side. The other half (with a tunnel entrance) blocks incoming items.

This last fact is important, because it can be used to do some tricks.

Moving other Entities: About highways, advanced defenses and moving boxes

Moving fast can be essential to defend alien attacks in time. Running on a belt will increase or decrease the movement speed of the player accordingly to the belts speed. That is why building a belt towards your defenses can be beneficial.

However, the player is not the only unit that can be moved by transport belts. Also, biters and spitters can be moved. This can be abused to improve your defense. Firstly biters will have a harder time to reach your walls when placing express transport belt in front of them. Secondly spitters can be moved closer to your walls. That way more turrets can attack a single spitter at once.

Another useful usage are cars on transport belts. Cars have an inventory and can be filled by inserters. So they can be used as moving boxes on belt. This has several advantages: Firstly the throughput of the belt-car-boxes is amazingly high, secondly the inserter stack size bonus does apply here and make inserters more effective.

      

Expert

This section needs cleanup. It contains all links from deleted subpages or duplicate articles.

• Transport network
  • Transport belts
  • Splitters
  • Underground belts
• Transport
• Crafting network
• Logistic network
• Intersection with 4 belts from every side, outdated
• Transport belts/Transport other entities: even the car can be transported with belts.
• Why do belts not require power?: Some reasons...
• Transport belts/Speedup Walking: Walk/run in belt direction add the speed of the belt to your own.
• Transport belts/Defense: Use the Express belt to slow down the enemies
• Transport belts/Physics
• Transport belts/Turns
• Transport belts/Blocking items
• Transport belts/Side insert
• Transport belt Optimising
• Throughput and bottlenecks.
• Speed, Distance, Throughput, Compression
• Tutorial for Belt Speed, Density and Throughput
• Transport belts/Belt lane for more about usage of the two lanes of a belt.
• Transport belt Optimising
• Transport belts/Turns for details about turns.
• Transport belt Optimising about other ways to speed up this bottleneck.
• Underground belts/More uses
• Three belts in two tile-lines
• Two belts in one tile-line
• Join two lanes into one

• Splitters/Priority: splitter prefers one side for joining in most cases.
• Splitters/When is a faster splitter needed?: a basic splitter can keep up with the input of one fast belt, if the two output belts are connected and empty.
• See example usages in this thread.
• Splitters/Weighted splitters: Use splitter to achive special ratios on the outputs
  File:Factorio ratios.jpg

  Splitters/Weighted splitters
  • Splitters/Cascading: Use Cascading to fill storages only, when not needed otherwise
• Splitters/Balancer: use the two lanes of a belt.
• Splitters/Joining: more explained
• Splitters/Wormhole Trick: an empty splitter transports items faster, they disappears on input side and dive up on output side, "jumping" over about half a tile. It is questionable, how this behavior could be used. A good usage is to make something like a "micro-buffer", or a "spread-buffer" with that, because a line of 10 splitters can store about 60 items - a half stack - and the first items are delivered very fast, but the last items have the normal belt speed to move through the splitters; so the items are spread on the belts. See also Splitters as the bus - The Splitter Bus
• Splitters/Constructions: Examples of using.
• || Using belts for defense