Tutorial:Train Throughput

Introduction

I'm putting this together to help other players figure out how to best utilize trains to transport items while maintaining a stable production throughput.

Main Goal

In order to ensure item throughput is maintained between both ends of a train route, the train must take less time to complete it's round-trip route than it would take for the produced items to fill the train's freight cars.

Example Problem

Let's say you're producing 600 iron ingots per minute on one corner of the map. You want to use all of that output and produce 600 iron rods per minute on another corner of your map. You want to transport those iron ingots using automated trains. I'll use this as a reference throughout the article.

Train/Station Setup

You can set up your route however you like, with as many train stations along the route as you like. Just be prepared to expand your stations, as you may need to add more freight cars to your train.

You can place locomotives on the same train facing in opposite directions, allowing for a train to travel frontwards and backwards along it's track. This may make route creation simpler, however changing the stations after the fact may be challenging and change where items are dropped off.

Single direction trains make train station setups and their subsequent expansions easier, but will require more work on route set up.

Approximate how many freight cars you may need, keeping in mind that this may change, as will your stations.

You can have multiple locomotives in the same direction, which will increase acceleration and deceleration, but will not increase max speed.

Route Duration

Grab a stop watch and time the entire route, starting and ending on the same station. If a train doesn't load/unload at a station, add 25 seconds. For simplicity, convert the final time to seconds.

For our example problem, lets say the route took 9 minutes(') and 40 seconds("), and that the train didn't load at two stations on the way:

9' + 40" + (25" * 2) =(9' * 60") + 40" + (25" * 2) =630"

Freight Car Fill Time

To figure this out we need two values: - Rate of production - Item stack size

There are 32 inventory spots on a freight car.

To calculate the fill time we would divide the maximum item capacity of a freight car by the item's production rate.

If we're producing 600 iron ingots per minute, and iron has a 100 item stack size then:

32 * 100 / 600 = 5.33' = 320"

Adjust and Re-Test

If you want to ensure the throughput is maintained on both ends of a train route, adjust the number of freight cars so that it takes longer to fill them than it takes the train to complete it's round trip.

With our above example, if it takes 320 seconds to fill a freight car, and the round-trip route takes 630 seconds, then we would need at least two freight cars for the iron ingots since it would take 640 seconds to fill them.

Since adding freight cars increases route times, make sure to time them again and ensure that proper throughput is achieved.