Is this intersection going to work?

[mikedubayou]

https://steamuserimages-a.akamaihd.net/ ... E15FD2AE5/

Before I go throwing this all over the place, Id like to get any advice here.

[Feardis]

Would it work:
depends what you're looking for...
It will work BUT this is by far.... a long way from being optimized... and definitely not for use if you expect having high train throughput

You can try this:
http://prntscr.com/eo6gn5

Or if you have to keep you lane very close to each other, then your setup + added signals (although I don't recommend it)
http://prntscr.com/eo6grb


Or this very popular and common one here:
https://i.ytimg.com/vi/aT_PjRqU664/maxresdefault.jpg

[mergele]

As long as you don't want your trains turning left or need very high throughput it will work.

[Engimage]

This intersection will work without errors but it has the following problems:
1. Trains can only turn right which is most likely a major issue as trains can't return the same way they came
2. The whole intersection is a single signal chunk so any train entering it will effectively block any others from entering. This is true even for trains on oncoming courses.

I would personally discourage you from:
1. Using tracks that close from each other. This leads to the situation where you just can't fit required signals in between like you have currently.
2. 4-way intersections are bad. Just try to avoid them. Or you have to end in solutions like MadZuri's design https://i.ytimg.com/vi/aT_PjRqU664/maxresdefault.jpg

[Aeternus]

4 way intersections have their time and place - if you're branching out towards mining outposts with low traffic volume, they can work. The disadvantage of them is bottlenecking traffic volume, but the advantage over multiple meshed 3 way connections is deadlock prevention - the entire intersection remains blocked until traffic has cleared it after all.

Your design can be improved to this to allow full turning from any side to any side:


For higher traffic volumes a roundabout is more efficient, but for low traffic volume, this design works well. You got room to put big power poles in the middle as well, so you can run power to any outposts between the tracks (in my screeny I also run red and blue circuit signals).

[Engimage]

4 way intersections have their time and place - if you're branching out towards mining outposts with low traffic volume, they can work. The disadvantage of them is bottlenecking traffic volume, but the advantage over multiple meshed 3 way connections is deadlock prevention - the entire intersection remains blocked until traffic has cleared it after all.

Your design can be improved to this to allow full turning from any side to any side:


For higher traffic volumes a roundabout is more efficient, but for low traffic volume, this design works well. You got room to put big power poles in the middle as well, so you can run power to any outposts between the tracks (in my screeny I also run red and blue circuit signals).

This intersection defies the most important rule.
You have to get NORMAL signals on the exit from your intersection and a chain signal on the entrance. This will open up chain signal if the exit block (after normal signal) is free letting your train not only enter the intersection but also exit it completely. If you put a chain signal on exit this would mean that both entrance and exit signals will be dependent on the next normal signal on the route which might be really far forcing a train to block intersection until it actually exits that second block with a normal signal before it. So the troughput is way exessively overlimited.
So this intersection, while it will work fine with no other intersections nearby, will be a major bottleneck in the train traffic.

[aober93]

Sure works ,but its not good. No left turns

[Aeternus]

This intersection defies the most important rule.
You have to get NORMAL signals on the exit from your intersection and a chain signal on the entrance. This will open up chain signal if the exit block (after normal signal) is free letting your train not only enter the intersection but also exit it completely. If you put a chain signal on exit this would mean that both entrance and exit signals will be dependent on the next normal signal on the route which might be really far forcing a train to block intersection until it actually exits that second block with a normal signal before it. So the troughput is way exessively overlimited.
So this intersection, while it will work fine with no other intersections nearby, will be a major bottleneck in the train traffic.

Gah, you're absolutely right. That was a bit of a rushjob that screeny ^.^ Forgot something.

[reallyLost]

For higher traffic volumes a roundabout is more efficient, but for low traffic volume, this design works well.

I don't understand why would you ever use that design over a roundabout for any traffic volume. As far as I can tell it just uses more track for no advantage, does it not?

[Aeternus]

For higher traffic volumes a roundabout is more efficient, but for low traffic volume, this design works well.

I don't understand why would you ever use that design over a roundabout for any traffic volume. As far as I can tell it just uses more track for no advantage, does it not?

This design is slightly more compact, and somewhat simplistic. It uses slightly fewer rail then the roundabout with bypass, slightly more then the roundabout without bypass. But yea, if you have the room, roundabouts are the way to go.

[impetus maximus]

intersections MUST have separate blocks for opposing tracks in my opinion.
trains stopping for trains that aren't crossing it's tracks is poor design.

here is the 4 way intersection i came up with. (left side drive. i live in the US)

max's.4way.png (717.36 KiB) Viewed 15246 times

up to 3 trains can pass each other without stopping inside it. from S to W, E to N, and N to E for example.
the only thing that i can tell a round-about has over this, is the ability for a train to turn around.
which i have no use for.

[reallyLost]

intersections MUST have separate blocks for opposing tracks in my opinion.
trains stopping for trains that aren't crossing it's tracks is poor design.

Yeah, absolutely. Nothing else is ever going to scale to any moderate amount of traffic.

up to 3 trains can pass each other without stopping inside it. from S to W, E to N, and N to E for example.
the only thing that i can tell a round-about has over this, is the ability for a train to turn around.

Well, a roundabout with bypass lanes can also have the same three trains passing each other. The roundabout will be slightly larger though.

[Aeternus]

intersections MUST have separate blocks for opposing tracks in my opinion.
trains stopping for trains that aren't crossing it's tracks is poor design.

here is the 4 way intersection i came up with. (left side drive. i live in the US)

max's.4way.png

up to 3 trains can pass each other without stopping inside it. from S to W, E to N, and N to E for example.
the only thing that i can tell a round-about has over this, is the ability for a train to turn around.
which i have no use for.

Very nice design. You can add roundabout functionality by connecting the tracks where they split initially. Add a chain signal and it shouldn't hamper throughput

[Optera]

I have yet to see a rail network having roundabout or spiral junctions.
This design has more throughput than roundabout, looks realistic and can be easily used for left and right hand driving.

The image is from this album http://imgur.com/a/Kv77Z

[Aeternus]

I have yet to see a rail network having roundabout or spiral junctions.

Railway loops are not uncommon. Here's an example of a rail station with endloop at a cargo dock:


And here's an example of my own primitive design:

[Optera]

I have yet to see a rail network having roundabout or spiral junctions.

Railway loops are not uncommon. Here's an example of a rail station with endloop at a cargo dock:

image

As you said yourself that's a reversing or terminal loop, not a roundabout.
I was explicitly talking about roundabouts and spirals.

And here's an example of my own primitive design:

image

Tramways all over Europe have similar junctions.
However you'd hardly ever see 90° junctions in regional or international lines. I know only of one station in Germany that has 2 lines intersecting at almost 90° with one of them being elevated above the other.
Usually the two lines are merged into parallel tracks for the station and split again afterwards.

[DaveMcW]

1. Real life hates roundabouts and 90° corners because trains can't turn that quickly.
2. Factorio hates roundabouts because of path recalculation bugs.

[Hannu]

However you'd hardly ever see 90° junctions in regional or international lines. I know only of one station in Germany that has 2 lines intersecting at almost 90° with one of them being elevated above the other.
Usually the two lines are merged into parallel tracks for the station and split again afterwards.

I read about that some time ago, when I planned switches for my garden railway. Stress to rails is larger at high angles, because there are gaps in rails. Therefore such junctions are avoided if possible. They may be used on light tram rails, but they are not allowed on regular lines in Finland (as far as I know our rules are relatively similar than in other European countries)

[Optera]

I read about that some time ago, when I planned switches for my garden railway. Stress to rails is larger at high angles, because there are gaps in rails. Therefore such junctions are avoided if possible. They may be used on light tram rails, but they are not allowed on regular lines in Finland (as far as I know our rules are relatively similar than in other European countries)

Security regulations in Austria are very strict too, we invented bureaucracy after all.
Those intersections in the middle of nowhere we all build in factorio and ottd are illegal here.
Industrial spurs and other lines are not allowed to join a line outside a station and must be extended as parallel tracks into the nearest stations switches.

[Mehve]

...
2. Factorio hates roundabouts because of path recalculation bugs.

Is that a fact? I tend to stick with roundabouts by virtue of a "why not?" mentallity, unless I specifically want to deny the trains the option, but I've never noticed/encountered any particular bugs. But this is a definite thing?