Factorio Forums

I made a new Factorio world and decided to try to use trains. Is there any problem with this t-junction?

Edit: Sorry forgot the photo.

The signals within the curves will cause problems.
Also it's recommended to use chain signals as "entrance" signals, else your trains will stop in the intersection, deadlocking the other trains.

Is it necessary to use chain signals for when there is a merge in the track?

If two (or more) tracks merge to one, it's good to have chain signals, they read the state of the signal in front of them.
For example if you have 3 tracks merging to one, you place before the merging point chain signals and a normal signal after the merging point. the trains will then stop in front of the junction instead of on the junction.

Could you refer me to a t-junction design? I am having a bit of trouble.

swap the standard signal in the curve between the two tracks for a chain signal.

I use this.


But I ususally use some kind of passing place in order to be able to run two or more trains on a single track.

Hmm. I've tried that design but I don't like that only one train can move through the junction at once. I guess a passing place will do.

problem with Kajanor's T is that trains going opposite directions will be stopping for one another since they share a block.

here is what a right side drive should look like.
for you left side drive people like myself. (i live in the US BTW)
[edit] improved version

ToxicTiger wrote:I guess a passing place will do.

Well I use a completely different design: every train line has it's own track running through the map.
They are connected to a "central junction" where all the tracks run together.
This looks like this:

Shoutouts to my small screen...
The two tracks where a train is waiting are entrance tracks with passing places. All the other tracks are going to the outposts or the base.

In order to merge down 5 tracks down to one, I use this setup:


This thing works somehow.

Kajanor wrote:

ToxicTiger wrote:I guess a passing place will do.

Well I use a completely different design: every train line has it's own track running through the map.
They are connected to a "central junction" where all the tracks run together.
This looks like this:
Image
Shoutouts to my small screen...
The two tracks where a train is waiting are entrance tracks with passing places. All the other tracks are going to the outposts or the base.

In order to merge down 5 tracks down to one, I use this setup:
Image

This thing works somehow.

I thought circles were bad for junctions. But still interesting.

ok i found a another reason that left side drive is better than right side drive.
this T allows trains to go opposite direction including making a turn.
couldn't place the two signals i have circled on a right side drive T.

ToxicTiger wrote:I thought circles were bad for junctions. But still interesting.

As I said, this thing works somehow.
I know that roundabouts easily break things in Factorio.
But as there is not more than one train per roundabout running in that thing (= 2 trains can pass this thing as long as they only use one roundabout), they won't block each other.
All the other trains which want to use that thing have to wait until all the trains on the outpost tracks, moving towards the roundabout, have passed through. From my experience this is kind of a bottleneck of my factory but at least it works without brain damage.
I just can't explain how things work...

impetus maximus wrote:ok i found a another reason that left side drive is better than right side drive.
this T allows trains to go opposite direction including making a turn.
couldn't place the two signals i have circled on a right side drive T.

Well if you prefer right hand drive then you could just move a track one forward like this.

ToxicTiger wrote: Well if you prefer right hand drive then you could just move a track one forward like this.

true.

ToxicTiger wrote:

impetus maximus wrote:ok i found a another reason that left side drive is better than right side drive.
this T allows trains to go opposite direction including making a turn.
couldn't place the two signals i have circled on a right side drive T.

Well if you prefer right hand drive then you could just move a track one forward like this.

I thought you were the one seeking help ,now im confused

just want to also give examples of left side drive for other users.

ToxicTiger wrote:

impetus maximus wrote:ok i found a another reason that left side drive is better than right side drive.
this T allows trains to go opposite direction including making a turn.
couldn't place the two signals i have circled on a right side drive T.

Well if you prefer right hand drive then you could just move a track one forward like this.

This is wrong, it will cause a deadlock. Never place normal signals inside a junction.

It's actually pretty hard to deadlock a 3-way junction regardless of signalling, it requires there be a deadlocked loop from one of the exits to one of the entrances.

After much monitoring and tweaking, I deem this to be the perfectly signalled 3-way intersection:
Only downside is it's a bit chunky, but it will never deadlock, trains that do not cross will not stop each other, and trains that do cross will be allowed to pass as soon as the other train has left the crossing. Pretty sure this is as efficient as possible.

Note that I use chain signals on the exits too, this is because I noticed in some cases I had signals somewhat close to the intersection that caused a train to stop at a regular signal just past the intersection, but due to the length of the train it blocked the intersection. Using chain signals on the exits means you need much longer trains (or some stupid signalling) to block the junction.

EDIT: Something similar can be seen in the OP's image, say a train is Westbound but there is a train sat after the junction so the leftmost signal is red. The train will stop at it and even a single locomotive (I think, might need a wagon) will block the junction.

Deadly-Bagel wrote:After much monitoring and tweaking, I deem this to be the perfectly signalled 3-way intersection:

Okay, your intersection was slightly different from what I use. And I can't wrap my brain around if the differences matter or not... I use driving on the left despite being in the US because I like having the signals inside the rails...

So, here is your solution on the left and mine on the right, is there a functional difference? If so, what is it?