Help with two way single track intersection rail signals.

[Gintoki Sakata]

Hi i am fairly new to game and learned most from tutorials and online videos . Most of them tell to avoid using a 2 way track . If single direction is the way to go then i will make changes but if intersections in 2 way is possible i could use some help.

My setup is like this .

A


B x c


D

So one train loops between A and D while 2nd loops between B and c . Problem is i am trying to avoid collision at intersection x . It is pretty simple if it was one direction from A - D to B-c , but i cant figure out how to signal for both direction. First train is 3 units long 2nd is 6 units long.

[Fel]

A set of two 1-way rails is definitely the way to go when you start increasing the amount of trains you are using.

Basically, there is a set of "rules" that allow you to easily do signals for those:
1/ In long stretches without intersections, have standard rail signals at regular intervals (to allow multiple trains to follow each others since they are going in the same direction).

2/ Right before intersections (for the incoming rails) and through the whole intersection, use chain signals.

3/ Right after an intersection (for the outgoing rails), use standard rail signals.

3b/ If the next intersection is too close to fit a whole train between the two intersections, treat both intersections as a single one (do not put standard rail signals in between but chain signals instead).


When you use 2-ways rails, you need to add a few important rules:
4/ All parts that are 2-ways except right around train stops should be treated exactly like an intersection.
This means that there should be no standard rail signals except for the incoming side right before a train stop (at least a train length between the signal and the train stop).

5/ If you want to "break" the chain signals to allow more than one train at a time to travel, you need a short "exchanger" where 2 1-way rails replace the 2-ways portion for at least a full train length.
In that case, put a standard rail signal at the entrance for each side (after the branching) and a chain signal before they merge again.


You can technically make 2-ways work for a while but it will rapidly become problematic in term of throughput as you add more trains.

[Gintoki Sakata]

i am having difficulty understanding part 4 . So what you are suggesting is no signals except just before a station which encases the whole length . Is it because signals are open ended so a loop will basically block itself.

I think i understand the problem stems from always checking right side .

Wish they implemented signals better that we could just assign a specific area of rails instead of given system.
Seems its time to clear those bug nests and make some more railways. Thanks !

[Fel]

You can put signals, but only chain signals (to break the rails into "blocks").
Signals on 2-ways rails is pretty much the most complex use of signals, which is part if the reason why many new players struggle with them.

[knighttemplar1960]

https://steamcommunity.com/sharedfiles/filedetails/?id=2456666499
Each station is its own block. Then you make the rail from one end all the way to the other end one block with stations that are their own blocks on the other end. The through put is very bad because only one train can use the main rail at a time.

Low through put is OK when you are just getting started but once you expand its not good enough any more and its just easier in the long run to set up one way rails to start with.

[Warlord]

Originally posted by mOj:

Hi i am fairly new to game and learned most from tutorials and online videos . Most of them tell to avoid using a 2 way track . If single direction is the way to go then i will make changes but if intersections in 2 way is possible i could use some help.

My setup is like this .

A


B x c


D

So one train loops between A and D while 2nd loops between B and c . Problem is i am trying to avoid collision at intersection x . It is pretty simple if it was one direction from A - D to B-c , but i cant figure out how to signal for both direction. First train is 3 units long 2nd is 6 units long.

Doing a quote on your post, it looks like it's more of just a big cross. So the only issue is where the two tracks meet in the middle of the cross. That's simple (and normal, for two two-way systems crossing). Simply use 8 signals. One signal on both sides of each track coming out of (or going into) the cross. This should enclose the crossing as its own block, and each branch coming out as their own.

[Gintoki Sakata]

yea warlord the formatting messed up but yea basically its intersection of 2 single track 2 way rails .
A
|
|
|
B----------------------------------------X------------------------------------C
|
|
|
D

So the problem here is i dont use 2 engines like knight templar shows but use a small loop around each station and to make it bit complicated there are couple more stations ahead of each but without intersections so once train goes ahead of A ( which is my processing center ) to a smaller collection center train signals mess up . I think i will just save some sanity and make it single side only and probably some thing like knight templar linked .
Thanks guys

[impetus_maximus]

give this a try.

https://steamcommunity.com/sharedfiles/filedetails/?id=2618298236

[Azrael]

In your space I wouldn't use a 2-way-track except if it is a route that is used by only one, at maximum two trains (then using a passing loop so they can evade each other).

[Fel]

I wouldn't use the standard rail signals on that crossing unless you are absolutely certain that trains wouldn't block each others on the 2-ways portions.

[Warlord]

Originally posted by Fel:

I wouldn't use the standard rail signals on that crossing unless you are absolutely certain that trains wouldn't block each others on the 2-ways portions.

I don't know how many trains the OP has, but I kind of assumed it was a basic setup. That is, an A-B line and a C-D line that happen to intersect, one train on each. So the signalling should be purely to keep the trains from crashing if they happened to cross at just the right time. Based on that "feeling", it feels like everyone is giving too much advice for the setup.

If I'm wrong, and there are more than 1 trains per route, then the advice changes.

[Gintoki Sakata]

thanks impetus i will test it out . Also my smooth brain just made a ♥♥♥♥ loads of t3 belts and brute forced my first satalite launch hopefully one day i will figure out how signals work :)

[impetus_maximus]

Originally posted by mOj:

thanks impetus i will test it out . Also my smooth brain just made a ♥♥♥♥ loads of t3 belts and brute forced my first satalite launch :winter2019coolyul: hopefully one day i will figure out how signals work :)

you are welcome.

don't worry, like many things in factorio you'll have an 'ah ha!' moment and you'll have signals figured out.

[SeniLiX]

Signals might be complicated to figure out, but once you get it you will be like: "Duh! it's so simple!" :P

[deno70]

https://www.reddit.com/r/factorio/comments/4f38sk/factorio_train_automation_complete_parts_23_and/

Best help I ever got for my train set up