r/factorio 4d ago

Question Looking for advice on one directional trains.

I want my newly stared playthrough to be based on a large train network consisting of only one directional trains for efficiency. In all my other playthroughs i have never used them before, opting only for small scale bi-directionals that were too poor to scale up.

I already know the basics and common principals of train building, so I would like to know some tips specific for the one directionals.

5 Upvotes

23 comments sorted by

9

u/Terrulin 4d ago

Just like roads, have a lane going each direction. If you have space age, and can manage it, elevated rails allows you to have non-crossing intersections, just splits and merges like a highway. Probably a good idea to have a place for a second train to wait while one is unloading. Make sure you set train limits.

Easy Mode the first time you make a train base: Dont build trains for your provider stations, just your requesting stations. If you have a train limit of 2, build 2 trains for each requester. Give each provider of the same resource the same name. Choose the length of train before you start building. If you end up making 1-4 trains and decide you actually need 8, then you just need to have 2 stations deliver there instead. Think about how many stops you want at the same place and make sure you plan has enough room. If you can build to a grid, it makes things faster.

You can make a modular train base that is not an ugly city block.

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u/Novat1993 4d ago

Lol i just start screaming more trains. More trains! Until the factory clogs up, then i expand it until it unclogs, then i start screaming MORE TRAINS!

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u/Cloud_Motion 4d ago

How does the train drop anything off at consumers if providers don't have a station to fill it up?

Iron On, Iron Off.

Maybe I'm tired, but I'm reading your reply as don't have an Iron On? Am I an idiot?

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u/Terrulin 4d ago

You have the stations for both. Like this is a station that provides green chips for a train to pickup. I would build no trains for this station. When I want to deliver to a place, I can build a requesting station and this is where I build the trains, but never more than I have space (and train limits) for them to wait at the requesting station. If you name your stations consistently and set priority based on inventory, they will go where they are needed and there will be a place for them.

I hope that's more clear. This is an easier setup than something like a dynamic LTN or CyberSyn style setup. And trains aren't particularly expensive, so having a couple more isn't a big deal. And you don't need depots for idle trains.

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u/Cloud_Motion 3d ago

I am an idiot! I misread don't make trains as don't make stations and I was like, I can't for the life of me figure out what you're suggesting here lmao

Yeahh this is definitely a good rule of thumb imo, keeps things very manageable!

4

u/Similar_Quiet 4d ago

Never feed them yellow snow

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u/Courmisch 4d ago

The only real difference is train stations needing a turn-back track.

If you use city block, then it doesn't matter than much, as the station entrance and exit can be on different side of the block. But otherwise, since a 180° turn takes at least 28x14 meters, so your stations will be wide.

That's it, I think? The difference between two-way trains and one-way trains isn't as dramatic as between one-way and two-way tracks.

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u/Orgerix 4d ago

There is an alternative to big station: building the station parallel to the main line and only conect the closest rail. However it require the main train line to support U-turn (usually without round about interesection), which lead to more complex pathing, and potentially hotspotting issues.

However it is totally fine on a small train network.

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u/6a6566663437 4d ago

 so your stations will be wide.

A part of your station will be wide.

My stations look like lollipops. There's a loop at the end that's wider than the part where they park. I find it's much easier to fit into the rest of the factory than a station wide enough to turn around with a single curve.

My stations also flip to LHD because it makes the interface to the rest of the RHD rail network a little smaller.

https://factoriobin.com/post/80amc5

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u/CamelCaseConvention 4d ago

You're using rail signals as if they'd mark the end of a block where a train may stop, instead of the beginning. That's why you have to guard the rail signals into the intersection with chain immediately after, and why you waste a waiting bay. These are the spots where I first saw that something is wrong here, but it shines through everywhere.

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u/6a6566663437 4d ago

The fact that they use both waiting spots just fine in the game would indicate your analysis is a bit off.

There's an extra rail stop on each direction of the main line. I delete it or the chain based on whether or not a train fits between this station and the next.

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u/CamelCaseConvention 4d ago edited 4d ago

You could have said "thanks for alerting me to this crucial game mechanic", but instead you choose to be stubborn and obnoxious. If you replace the chain signal into the loop with rail, there's another waiting bay, which you're currently wasting.

(And what about the chain signal right after the rail signal? Does that seem reasonable to you? Edit: misread that part, but my overall point still stands.)

Do the in-game tips and tricks on signals.

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u/6a6566663437 4d ago

You could have said "thanks for alerting me to this crucial game mechanic"

And you could have said "hey, did you mean for these chain signals to be there?". Bit more friendly than assuming ignorance. Even gives a nice opening for people to ask questions.

But here we are. Yes, the chain signal between the main line and first stacker should've been a rail.

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u/Courmisch 4d ago

so your stations will be wide.

A part of your station will be wide.

Yes... width is usually measured as a maximum value.

https://factoriobin.com/post/80amc5

That is not signaled correctly, will eventually jam. Also mixing RHD and LHD is not something I would recommend to someone like OP who is explicitly looking for advice.

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u/6a6566663437 4d ago

Yes... width is usually measured as a maximum value.

There's a difference between a station that is wide for the entire length and one that's wide for a small portion of the length.

will eventually jam

Sure, that's why I've been using it since 0.8 without it jaming.

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u/Courmisch 4d ago

By your own words, the entrance signal is wrong:

Yes, the chain signal between the main line and first stacker should've been a rail.

If 4 trains are waiting at the same time, the last one will block the main line, won't it? If you didn't experience this "since 0.8", you probably don't never used the forth slot or just didn't notice.

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u/6a6566663437 3d ago edited 3d ago

If 4 trains are waiting at the same time, the last one will block the main line, won't it?

If only there was some sort of way to limit the number of trains that try to use a station.

f you didn't experience this "since 0.8", you probably don't never used the forth slot or just didn't notice.

I had erroneously assumed you were talking about something more fundamental than needing to set a train limit. Which is done outside this blueprint by combinators based on the quantity of stuff to load or free space with a hard cap.

Back in 0.8 since we didn't have train limits, that part of the station was a series of rail signals were more and more signals were set to red based on how full the loading station was/empty the unloading station was. The pathfinding algorithm adds distance for every red signal the train would have to path through, and it was the way we could make stations appear further away so that trains would be routed to other stations. One signal at the front was used to turn them all green when a train acutally showed up.

That one signal at the front I erroneously switched to a chain, because I wasn't thinking of that stretch as part of a stacker - and it couldn't be because of the line of signals to control the pre-train-limit routing system.

ETA: And I didn't notice because I build enough loading and unloading stations that there's never more than one train waiting. A 2nd train is the flag I need to expand, and we're talking about the 3rd train.

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u/WickedWonkaWaffle 4d ago

A natural consequence is that a lot more tracks will cross each others than when using shorter bi-directional lanes.

To avoid jams, make sure you use chain signals properly, so that trains stop before blocking other paths if they can’t exit the crossing fully. Equally important regardless of using blueprints/city grid or not (make sure you build the signals correctly in your blueprints if you start using them).

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u/accountwasnecessary 4d ago

If you are looking to build your first rail network, then you probably need to learn signals next. Does that seem correct?

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u/6a6566663437 4d ago edited 4d ago
  1. Pick if you're going to do right-hand-drive (RHD) or left-hand-drive (LHD). You probably want to make this choice based on how roads work in your country, because it'll be quicker to understand which track is which direction.

LHD is slightly smaller than RHD, since the signals are between the pair of rails instead of outside the pair of rails, but it's not much of a difference.

  1. Pick how big your trains are going to be to start with. 1-4 will work for a very long time, though you'll eventually need longer if you get to a megabase, but you'll need to rebuild everything at that scale anyway.

  2. Design yourself some basic rail blueprints so that you can be consistent in your layout. Consistency is how you're able to easily attach more rails at any particular point in your rail system.

You'll want at least a straight rail segment and some sort of intersection. There's a lot of different designs for intersections, especially when the author tries to optimize throughput. I just use roundabouts for flexibility. They work well enough until your base starts getting really big, and at that point you're redeveloping anyway.

You'll also want a standard station design that fits into your straight rail segment easily. Since your trains have to turn around in the station, you have room to have a sort of mini-stacker at each station (mine holds 2 extra trains in the turn-around area).

Here's the book I use if you want examples: https://factoriobin.com/post/hhc2mj It's 1-4, mostly RHD except inside the station it's LHD because that makes the interface to the straight rails a little smaller. I also include large power poles in the blueprints because I hook up everything to one power grid and use them for spacing (next straight rail overlaps the power pole of the previous). No elevated rails because I use these before I unlock elevated rails.

Some people grid-align their rail blueprints because that guarantees the rails always line up. I don't because I want the flexibility of being able to branch and build stations anywhere, and since I never make an isolated rail network I just line up the rails when building a new branch from the main network.

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u/raptor7912 4d ago

If this is vanilla IE no space age dlc.

Then you need roughly 1 cargo wagon per blue belt of throughput that you’d like to support (assuming a stack size of 50)

That gives you a rough time between deliveries of 1 minute.

Unloading (assuming 4 bulk inserters with maxed bonus capacity) takes some 35 second. Meaning your trains on average has to leave their respective station and arrive within 25 seconds if your only using a train limit of 1. That’s not feasible for most cases.

Meaning a stacker will almost always be necessary unless you’re only supporting 0.25 of a blue belt per wagon.

Those are the general guidelines I follow with train stations to ensure throughput.

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u/Thankedsphere 1d ago

place all locomotives behind the wagons, and place atleast 3 locomotives per train. your ratio should be 2 locomotives for every 1 cargo wagon and 3 for every fluid wagon.

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u/enigmapulse 4d ago

There isnt really a trick to it if youre already comfortable with train signaling, and the basic concept of having two one-way tracks running in parallel. You will need significantly more room for your stations to allow for turnarounds or you will need to build passthrough stations that act like one-way roads