Railway signal guide (official)

Finally after implementation of chain signals (or also called pre-signals) I providing to you a detailed guide how to use semaphores, and how they actually work.

Basic

Understanding the signal block mechanics

Signal block is area of the railway which ends with railtrack dead-end or another signal. If any train entire or it's part is on the block, all signals at enry of the block will become red.

Check out those scenarios for better understanding where exactly are the signal blocks:

Also you should avoid following scenarios - signal block ends with same signal as it start

Single directions signals can be passed only single direction!

If you have signal placed in one direction, train will never able to pass it vice-versa direction

To place single-direction semaphore, just after placing semaphore click once again to change direction, and again to change to vice-versa direction, and once again to revert back to double direction type

Understanding chain signals (or pre-signals)

Chain signal work like normal signal

If no train, it's green

If train in the block, it's red

It works different way in those scenarios:

Chain signal is red also when there is no free exit from the block - chain signal will not allow to pass the train, if the train is not able to exit the block.

If some of the exits from the block are engaged, and some free, chain signal will light up with a blue color. In case train can use the free exit, chain signal allows train to pass, in case train need to access the engaged exit, chain signal not allow train to pass.

Double track

Partial double track

Useful when you intend run like 2 trains on single track, you may make short double track where the trains can get around each other

Double track

Robust system for your railway network

Double track junctions

Legend

T Junction

Simple - at access to junction place the single direction chain signal, at exit from junction place the normal signal

X Junction

Follow same rules as T junction just you have 4 directions
Do not place the signals inside the junction

X Junction Advanced

With higher throughput (more trains can pass same time), but bigger place needed.
This time place signals also inside junction.. but you need maintan following rule.. between every crossing or juction need to be at least one signal.. when there will be any two crossing or junction without signals in between.. then it may not works and deadlock with train may occur

Stations on double track

Double track end-station (without turnabout)

Double track ended with 3-track custom house

Double track end-station (with turnabout)

Double track through-station (fixed direction)

Only one train per each direction same time
Train can't turn and return from same direction as he came from

Double track through-station (variable direction)

Two trains can enter same direction
Train CAN turn and return from same direction as he came from

Double track through-station (variable direction - with bypass)

Trains which not intend to stop on this station can bypass it

Understanding the limitations

While designing track you should always take into acount an maximum lenght of the train you will run on it, check following fails - trains too long for the track:


Also remember, when you will use robust two track system, there is limit how much train can be present on the track!

[Lou Sassle]

The "double track through customs" does not work for me. The trains just become confused and cant leave the border.

[Basil Peace]

I believe "Double track through-station" scheme should use mixed signals

[pawelkrzyzak]

New mixed signals - added but not explained here - combination of block and chain signal: should be placed before two way terminals following rules from the guid

[armagor]

Hi @ticho. It is one side pre-chain, and the other side regular signal.

[ticho]

Hi, what is MIXED signal, added into the game please? Could you add function and using example here in your guide? Thx.

[Levantine]

Blyatifully made!! You made my republiking much easier....

[Pacifick]

Merci !

[TogaEatingNoodle]

I have an issue under the three lane customs house. For some reason, the exit semafor that is placed next to the entrance chain one does not turn green and keep my trains trapped, any way to solve this?

[Xarro44]

If someone played with trains in factorio before playing this game, you have learnt about 85% of what you needed

[MacGregor]

OpenTTD's PBS signals would be really awesome.