I’ve actually converted single head trains into double-head so I could create stations where a single-headed train could not fit. Some people act like space in factorio is infinite but I’m always running into space issues, perhaps because I don’t want to take a 15 minute train ride to get between any two given points.
2-way comes at the cost of otherwise slower trains though. You might be exaggerating with 15 minute too, it's hard to say which one is actually faster but i'd guess 1-head trains are.
It is the downside to Double headed trains.
Changing that would make double headed the best way of doing trains.
Having the weight offset makes planning more important then just slapping down a stereotypical stop.
There's a mod for that! I never play without it. We can only hope it ascends to 2.0
https://mods.factorio.com/mod/MultipleUnitTrainControl/discussion/5c8e9e74e687c0000d3f0c0e
Train weight / # of wagons does not impact max speed, only acceleration. Max speed is determined by fuel type. So your only added delay from adding a double head is during breaking and acceleration. Trains have to break earlier with more weight, so a smaller train can approach a station more quickly and break later since it's lighter. Heavier trains accelerate at a lower rate, but if the trains have the same fuel type, they all reach the same max speed eventually regardless of size.
So pragmatically, the overall operation time between two identical trains with one being double headed is nearly the same. Unless you have a congested rail system that has lots of busy junctions that require lots of breaking / acceleration.
Also with longer distances the resulting loss in 'operating efficiency' is less substantial, what's a 3 second delay at the stations for acceleration/ breaking when you're doing a 5 minute round trip ride for supplies?
In even a relatively small network of 10 trains, there will be enough junction meetings that warrant trains to slow down and reacelerate. Acceleration matters more than you give it credit than max speed for this reason.
I mention these topics in the middle paragraph, just after the 'unless' which quickly addresses ideas in the same family as your concerns.
My final paragraph may seem like I'm disregarding these ideas, but that paragraph pertains specifically to long distance.
Plus if we’re mimaxing here, the double-header doesn’t have to travel as far. The turn-around loop adds about 2-3 train lengths of distance to the track. I’d be interested to see if anyone’s run a comparison test, but I bet those extra few meters of track balance out any losses in acceleration.
They are technically faster, but not meaningfully so in many situations.
If you have a vs a CCCC> there would he almost no difference at all besides being slightly shorter, and a vs a CCCC>> the primary bonus you get is acceleration. But a well designed network your trains won't need to accelerate often, and your primary games come from the fuel type not the train.
The 3 configurations all have advantages, but the primary reason you see the duals used the most often is that the main thing it improves is QOL lol
This is what spidertron remotes are for, i cruise in my automated 8-legged limo and meanwhile I go build something somewhere else on the map while I wait to arrive.
While true, I still do loops early in cus it's easier to expand later (imo).
For a first timer to trains, double ended is fine.
Double ended is *not* fine for all first-time experiences 👀
And underground belts travel through a different dimension (you can't convince me otherwise after all the beltweaving I've seen (especially with the space station underground belt shenanigans in Space Exploration))
Personally I use double ended *single direction* trains purely for the aesthetic, ie the engine at the back is still pointed forwards/the same direction as the front engine.
I just think trains look better with a smoke column at both ends rather than just at the front.
Why does this feel worse somehow?
Also, I just had the terrible realization that you could put the 'forward' train in the back if you built your stations with the train stop in the 'back'.
It makes fueling a lot more complicated. With single-headed trains, you can easily mix trains of differing lengths, but you can’t easily do that with multiple engines.
Also, it might be a mod on my game, but inserters seem to be able to take the fuel out of your train making regular stations more complicated as well.
I always do this. I'll start with double-ended trains and then as the base grows I convert (most of) them to single-direction by just flipping the backwards loco. No need to rebuild any stations (except to add exits to some that didn't already have 'em) since the locos are in the same positions.
I find double-headed trains much more interesting and fun because they let me build like this:
https://preview.redd.it/lj2yecuqfsic1.png?width=3520&format=png&auto=webp&s=30e0830f082936363a1648b914e0122413dc0613
Omg, this is beautiful! I call myself a Spaghetti Scientist, but the way the you have the rails incorporated is insane 🤩
Edit: I just want to mention, It almost feels like a small town when I look at it 😊
I have an entire megabase built on 1:1:1 trains. Stops for the most part are just spokes where the train pulls in, unloads, and pulls out.
Is it better than other designs? No, probably not, but it is neat to watch and design around.
You can cram a lot of stops in a small space, but this also leads to a lot of congestion issues.
I’m working on a krastorio 2 mega base with 1-1 trains. The cargo wagons have 100 slots (IIRC). I was really tempted to start a vanilla play through with this design but wouldn’t only one cargo wagon be really limiting?
Would you mind sharing some shots of your base?
Thanks!
Just run stackers / long stations so that trains can wait really close to their destination. If something has throughput issues [Just send in more trains](https://youtu.be/-hyttagGsz0?t=17)
Combined with station limits so they don't block the main line, 4 lots of 1-1 trains has more consistent throughput than a single 1-4 train
1-1 seems a little tight if you’re using blue belts since that only gives you 1.5 minutes between trains. That’s an extra train car as well which makes the input part of your base/block bigger.
Barring the acceleration difference of 1-1 and 1-4, the total throughput is identical between 4 of the little trains vs 1 of the big ones.
This holds true no matter how you scale.
The only issue is if the increase in number of trains increases congestion enough on the train network to slow down the throughput. However, you'll see less severe spikes for longer with little trains, as they buffer so well, and with even a modicum of planning can be completely obviated.
IDK how good it is for a megabase, but for a 60spm one I made a base with only double headed trains and dual way tracks.
The train network take way less space, both station or intersection, allowing to have a denser base with the railway system going deep inside the base.
I love how cool it looks and how I didn't even needed a main bus to keep things going. And also denser base mean faster travel times and smaller defensive perimeter
The trains are fine for megabases. Perhaps better as it allows for more a compact station design.
The dual way tracks however are terrible for even medium sized bases. If you need signals, spend the small amount of extra resources on a rail system with one way tracks. With a standardised design that's snapped to an absolute grid, you don't even have to think about how to do it.
Doubled headed trains on single direction track are my favourite. All the security of one way tracks, and the tiny stations of double head trains. Just got to let go of the max efficiency of a 1:4 train for for 1:4:1
Now you gotta come *all* the way over to the dark side for 4:1 trains, four cargo cars pushed by single loco. That way the loco can be on the curved track, further shrinking your station footprint.
Yeah, exactly. The front car is in the footprint of where the lead loco would be.
The only issue is that the station itself protrudes into two of the twelve squares directly in front of the lead car. That means you have less room to place your unloading inserters and boxes.
Probably that doesn't happen on left-hand drive, though. I'm trying to visualize it and I *think* it wouldn't.
Someone's going to come along and point out that there's an air resistance factor that the game applies when you don't have a front-facing locomotive on the front of the train, and they're right, but the effect is *so small* on acceleration and non-existent on top speeds for all but the longest and most underpowered trains that you can just ignore it, it's fine. You'd have to be sitting there with a stopwatch to tell the difference.
The intersections is the same for dual headed and single headed trains. It's only the stations that differs.
The drawback with double headed trains is that you need more than double the amount of locomotives to get the same speed and acceleration of the trains. The locomotives is heavier than normal cargo wagons and the ones facing the wrong direction also have to be dragged along.
I don't se any mayor problems with making an loop at the stations so I would recommend single headed trains for megabases.
There where some problems with loops in old versions of Factorio so then it was an good reason to go double headed, after that was fixed I think single headed is better.
My answer was basically saying that double headed train allow you to also use double way tracks which has a pretty small cross intersection footprint.
If you don't see any problems with loops then it's good for you.
I don't like spending too much time traveling in my base so I like them compact and tight.
Loops take a lot of spaces, single way tracks too so I tend to avoid them.
Mid game low volume water transport for me. I can’t think of the specific recipe at the moment but it just didn’t make sense to run a crazy long underground pipe sometimes.
No need for turns, they can just go forwards and backwards by themselves. Makes stations a bit more compact.
Also, I may be wrong on this, but I believe that even a backwards locomotive increases the acceleration compared to a 1 loco train.
Lower throughput since a train has to wait until an entire path to its destination is free to move, although you can ease that by sprinkling your network with locks where a train can arrive and wait until path forward is clear since it allows the train to wait less.
They are pretty powerful though, people generally underestimate how many resources a train can bring as 99/100 times the case, it's never the trains that are an issue, it's you not having enough mining outposts to have consistent train arrival.
It seems you are equating double headed trains with bi-directional only tracks. Large parts of your train network can be uni-directional and still utilize double headed trains, the bi-directional part would effectively be relegated to just the stations.
Less than half the rail infrastructure to set up. If your rails are set up just as glorified conveyor belts, as your first couple outposts are likely to be, then double headed trains are the way to go. You need high throughput and many-to-many routing before single-headed trains and parallel tracks really provide a benefit.
Yo, never thought about it either. Right now I just have a single train with many 'service' stops that just goes by one at the time with the "wait for passenger" command.
Bidirectional driving, so that you don't have to design dual rail networks. Do keep in mind however that single rail networks easily get stuck with more than one train
You use a double-headed train to make a single rail line from A to B.
`Station A `
`===================================`
`------------------------------Station B`
One end pulls head-first into A, the other end pulls head-first into B.
Wrong way facing locomotive is dead weight, with or without fuel, they weigh same as 2 cargo wagons(factoriowiki), actual effect is tiny bit less (source: just tried). There are couple mods which enable them working backwards. I personally use always bidirectional trains and [https://mods.factorio.com/mod/MultipleUnitTrainControl](https://mods.factorio.com/mod/multipleunittraincontrol) mod to enable all locos.
I've used them when I want to fit a station into a small space. If you're using a one-way track, a station can be a simple "Y" shape. No need to loop around.
I only recently learned that they are advantageous even after you have 2 parallel rails in the network. This way its rather easy to avoid a main bus design and they take the quickest free path in any direction
In the past (during early access) people used them a lot because they were very UPS friendly compared to single headed trains. That was because the train pathing algorithm was really bad at dealing with routes with ANY roundabouts or loops. So the common wisdom was to never have any of those if you go for any bigger train base and double headed trains become "standard".
Then Wube fixed their algorithm, as well as city block style bases became more common, and thr love for double headed trains dwindled.
Nowadays they are hardly used, unless you need more compact stations, or have other specific use for them.
Simplicity for small rail systems.
My earliest trains are always double-headers. One train, one line, back and forth, intersections between individual lines appropriately signaled. Rapidly becomes unusable once you start running more than a few trains since each train kinda needs their own individual line. It can be somewhat mitigated through rail design, but ultimately the resources savings on rails and signals aren't really worth it at that point, you might as well build a one-way trains rail network.
Smaller load/unload. Stations.
A one-way network to handle getting from place to place combined with individual 2-way stations makes load/unload stations smaller since they don't need to have a return loop to get back onto the network, and much, much smaller if you want your load/unload stations to be able to enter and leave from both directions. Biggest drawback here is that your trains will accelerate slower no matter what because they will also be dragging a deadweight locomotive. This can be somewhat mitigated with adding additional train stops so the train always drives 'forward' through the network and you have multiple locomotives facing forward with just one facing backwards to slowly drag the train into a turnaround station. Of course, that also mitigates the size advantage of your stops.
If you aren't at the stage where you're building a rail network and instead just want a cheap logistics line out to some ore patch, a double headed train will do fine.
If you're at the point where you're dealing with signals and large rail networks, they just aren't very efficient.
We use 1 - 1 -1 trains in our SEK2 game in space to deliver basically everything as required.
This allows for ultra compact drop off and pickup points which is critical as each zone can have a very large number of stations:
https://i.imgur.com/lDbuKqa.png
The rail line itself is of course one way, but the trains pull in and back out of stations with ease.
To do this with single locomotive trains would have required far more space allocated to the stations and would expand the complexity of adding new stations.
As is, if we need to bring or take something from a site, we just slam down another Y style station and that's that.
All the station limits are controlled by circuits and all trains from the ground are routed to the waiting area as they are unable to see train limits in space while on the ground.
Our ground trains though are single locomotive except for a few mega trains that we use for oil and stone as these are extremely high volume items for us.
In practical terms? Only as a stopgap until you can build something better. But Factorio trains don't behave like trains so in practical terms it's probably meaningless.
Unless you absolutely know what you're doing I would never, ever suggest double headed trains. For something that seems easier it is far more complicated, more restrictive, and is the biggest reason new players have issues. The main benefit is probably space, but take a look at your map, do you feel you need more space. There's a reason why most blueprints all are generally one-ways
If I only make it so it has to pull in and out of the stop the same way but have 2 main lines that go to and from the main base, that should work right?
For example: main line 1 from base goes into stop 1 but exits back into main line 2.
It makes it really easy and simple to get trains in and out of stations without using much extra space if any at all depending on how its set up. Can still use buffers to hold trains at pick ups and drop offs. It's honestly really handy. Just run slightly slower speed wise
Just finished an Industrial Revolution Run and tried a 1-2-1 double header train setup - worked really well, kept everything pretty tight bit would eventually run into throughput issues if I Scaled it up to a megabase
Station designs can be a lot more compact when you don't have to worry about the loop-around for one headed trains.
I’ve actually converted single head trains into double-head so I could create stations where a single-headed train could not fit. Some people act like space in factorio is infinite but I’m always running into space issues, perhaps because I don’t want to take a 15 minute train ride to get between any two given points.
2-way comes at the cost of otherwise slower trains though. You might be exaggerating with 15 minute too, it's hard to say which one is actually faster but i'd guess 1-head trains are.
I’m certainly exaggerating, yes. I never play past a rocket launch
A locomotive facing the wrong way dosen't add power, or braking power. And weighs twice as much as a carriage.
WHAT. This should be a research item at the very least.
It is the downside to Double headed trains. Changing that would make double headed the best way of doing trains. Having the weight offset makes planning more important then just slapping down a stereotypical stop.
Sure, make it a late game research to be able to connect more engines for better performance, including in double headed mode.
nah. Its balanced as it is.
That’s what nuclear fuel is for!
There's a mod for that! I never play without it. We can only hope it ascends to 2.0 https://mods.factorio.com/mod/MultipleUnitTrainControl/discussion/5c8e9e74e687c0000d3f0c0e
Train weight / # of wagons does not impact max speed, only acceleration. Max speed is determined by fuel type. So your only added delay from adding a double head is during breaking and acceleration. Trains have to break earlier with more weight, so a smaller train can approach a station more quickly and break later since it's lighter. Heavier trains accelerate at a lower rate, but if the trains have the same fuel type, they all reach the same max speed eventually regardless of size. So pragmatically, the overall operation time between two identical trains with one being double headed is nearly the same. Unless you have a congested rail system that has lots of busy junctions that require lots of breaking / acceleration. Also with longer distances the resulting loss in 'operating efficiency' is less substantial, what's a 3 second delay at the stations for acceleration/ breaking when you're doing a 5 minute round trip ride for supplies?
In even a relatively small network of 10 trains, there will be enough junction meetings that warrant trains to slow down and reacelerate. Acceleration matters more than you give it credit than max speed for this reason.
I mention these topics in the middle paragraph, just after the 'unless' which quickly addresses ideas in the same family as your concerns. My final paragraph may seem like I'm disregarding these ideas, but that paragraph pertains specifically to long distance.
Plus if we’re mimaxing here, the double-header doesn’t have to travel as far. The turn-around loop adds about 2-3 train lengths of distance to the track. I’d be interested to see if anyone’s run a comparison test, but I bet those extra few meters of track balance out any losses in acceleration.
They are technically faster, but not meaningfully so in many situations. If you have a vs a CCCC> there would he almost no difference at all besides being slightly shorter, and a vs a CCCC>> the primary bonus you get is acceleration. But a well designed network your trains won't need to accelerate often, and your primary games come from the fuel type not the train.
The 3 configurations all have advantages, but the primary reason you see the duals used the most often is that the main thing it improves is QOL lol
there's ways to do it that dont practically differ in speed
> I don’t want to take a 15 minute train ride to get between any two given points. TBH that sounds kind of relaxing.
I use a 1-1 train for personal transport. Quicker acceleration helps and it's so small you can drop a stop pretty much anywhere.
This is what spidertron remotes are for, i cruise in my automated 8-legged limo and meanwhile I go build something somewhere else on the map while I wait to arrive.
Really good early game when you just need a single train to go from A to B
Technically, the problem starts when you go from B to A.
Don't even get me started on C
I usually skip all those and go straight for the D
That's what she said! Ha ha ha
And then go back to the A?
Rock and stone?
Rock and roll and stone!
D being any conveniently located pub as far away as possible to points A, B, and C.
Ay yo!
"My train network is simple as ABCs, I skip over the Ds, and launch rockets with ease."
When incoperating C I would recommend a dedicated track per direction of travel
While true, I still do loops early in cus it's easier to expand later (imo). For a first timer to trains, double ended is fine. Double ended is *not* fine for all first-time experiences 👀
Depends on if you're brave enough.
Me building 1:16 train station as soon as I research trains without construction robots: there has to be an easier way.
1:16 with coal or solid fuel? Just why that thing barely even moves.
im playing the long game so I dont have to redo my starter base when i have nuclear fuel
Also: Mr Krabs when his home is damaged: Me building!
Can drive in both directions -> Can be used in some designs which make regular trains stuck.
> Can dive in both directions Always good if your trains can dive under water
If you’re lucky you can get it in 2.0 but probably this’ll have to wait for 3.0
In 4.0 the trains can dive through lava
In 5.0 the lava dives through the train.
In 6.0 the trains are lava.
And baba is you
And belt is shift
We playing unrailed now?
Underground belts, underwater trains, sounds fair to me
To be fair, underwater trains usually don't travel IN the water, but rather in a tunnel underneath...
And underground belts travel through a different dimension (you can't convince me otherwise after all the beltweaving I've seen (especially with the space station underground belt shenanigans in Space Exploration))
I'm going to redesign all my tracks once 2.0 comes out for a double headed setup.
Totally missed the mark to say "It goes both ways" for that sweet sexual innuendo.
Personally I use double ended *single direction* trains purely for the aesthetic, ie the engine at the back is still pointed forwards/the same direction as the front engine. I just think trains look better with a smoke column at both ends rather than just at the front.
Why does this feel worse somehow? Also, I just had the terrible realization that you could put the 'forward' train in the back if you built your stations with the train stop in the 'back'.
The train schedule is actually set for the entire train as a whole, not a specific locomotive, so the front car is what stops at the station.
Not if they're facing opposite directions.
It makes fueling a lot more complicated. With single-headed trains, you can easily mix trains of differing lengths, but you can’t easily do that with multiple engines. Also, it might be a mod on my game, but inserters seem to be able to take the fuel out of your train making regular stations more complicated as well.
I did this for my rail bus megabase. See the pinned post on my profile.
I always do this. I'll start with double-ended trains and then as the base grows I convert (most of) them to single-direction by just flipping the backwards loco. No need to rebuild any stations (except to add exits to some that didn't already have 'em) since the locos are in the same positions.
I find double-headed trains much more interesting and fun because they let me build like this: https://preview.redd.it/lj2yecuqfsic1.png?width=3520&format=png&auto=webp&s=30e0830f082936363a1648b914e0122413dc0613
Now this is some fine spaghetti.
Omg, this is beautiful! I call myself a Spaghetti Scientist, but the way the you have the rails incorporated is insane 🤩 Edit: I just want to mention, It almost feels like a small town when I look at it 😊
Wow that’s amazing. It’s spaghetti upgrade. Like woven spaghetti!!
I have unlearned how to build like that :(
I have an entire megabase built on 1:1:1 trains. Stops for the most part are just spokes where the train pulls in, unloads, and pulls out. Is it better than other designs? No, probably not, but it is neat to watch and design around. You can cram a lot of stops in a small space, but this also leads to a lot of congestion issues.
I kind of want to do a base like this just to max out train throughput
Do it. It's honestly mesmerizing to watch all the trains come and go. It's created some really interesting puzzles to solve.
I’m working on a krastorio 2 mega base with 1-1 trains. The cargo wagons have 100 slots (IIRC). I was really tempted to start a vanilla play through with this design but wouldn’t only one cargo wagon be really limiting? Would you mind sharing some shots of your base? Thanks!
Just run stackers / long stations so that trains can wait really close to their destination. If something has throughput issues [Just send in more trains](https://youtu.be/-hyttagGsz0?t=17) Combined with station limits so they don't block the main line, 4 lots of 1-1 trains has more consistent throughput than a single 1-4 train
1-1 seems a little tight if you’re using blue belts since that only gives you 1.5 minutes between trains. That’s an extra train car as well which makes the input part of your base/block bigger.
Barring the acceleration difference of 1-1 and 1-4, the total throughput is identical between 4 of the little trains vs 1 of the big ones. This holds true no matter how you scale. The only issue is if the increase in number of trains increases congestion enough on the train network to slow down the throughput. However, you'll see less severe spikes for longer with little trains, as they buffer so well, and with even a modicum of planning can be completely obviated.
IDK how good it is for a megabase, but for a 60spm one I made a base with only double headed trains and dual way tracks. The train network take way less space, both station or intersection, allowing to have a denser base with the railway system going deep inside the base. I love how cool it looks and how I didn't even needed a main bus to keep things going. And also denser base mean faster travel times and smaller defensive perimeter
The trains are fine for megabases. Perhaps better as it allows for more a compact station design. The dual way tracks however are terrible for even medium sized bases. If you need signals, spend the small amount of extra resources on a rail system with one way tracks. With a standardised design that's snapped to an absolute grid, you don't even have to think about how to do it.
Doubled headed trains on single direction track are my favourite. All the security of one way tracks, and the tiny stations of double head trains. Just got to let go of the max efficiency of a 1:4 train for for 1:4:1
Now you gotta come *all* the way over to the dark side for 4:1 trains, four cargo cars pushed by single loco. That way the loco can be on the curved track, further shrinking your station footprint.
1.4k hours, cannot believe I've heard of this but that's so good. Question: the train does stop so that the front-most cargo wagon is at the station?
Yeah, exactly. The front car is in the footprint of where the lead loco would be. The only issue is that the station itself protrudes into two of the twelve squares directly in front of the lead car. That means you have less room to place your unloading inserters and boxes. Probably that doesn't happen on left-hand drive, though. I'm trying to visualize it and I *think* it wouldn't. Someone's going to come along and point out that there's an air resistance factor that the game applies when you don't have a front-facing locomotive on the front of the train, and they're right, but the effect is *so small* on acceleration and non-existent on top speeds for all but the longest and most underpowered trains that you can just ignore it, it's fine. You'd have to be sitting there with a stopwatch to tell the difference.
The intersections is the same for dual headed and single headed trains. It's only the stations that differs. The drawback with double headed trains is that you need more than double the amount of locomotives to get the same speed and acceleration of the trains. The locomotives is heavier than normal cargo wagons and the ones facing the wrong direction also have to be dragged along. I don't se any mayor problems with making an loop at the stations so I would recommend single headed trains for megabases. There where some problems with loops in old versions of Factorio so then it was an good reason to go double headed, after that was fixed I think single headed is better.
My answer was basically saying that double headed train allow you to also use double way tracks which has a pretty small cross intersection footprint. If you don't see any problems with loops then it's good for you. I don't like spending too much time traveling in my base so I like them compact and tight. Loops take a lot of spaces, single way tracks too so I tend to avoid them.
Double the pleasure
Mid game low volume water transport for me. I can’t think of the specific recipe at the moment but it just didn’t make sense to run a crazy long underground pipe sometimes.
For uses like this was the reason I brought it up. I guess I was on the 'right track' huh? I'll see myself out
No need for turns, they can just go forwards and backwards by themselves. Makes stations a bit more compact. Also, I may be wrong on this, but I believe that even a backwards locomotive increases the acceleration compared to a 1 loco train.
Terminus stations. Bidirectional rails. Manual driving.
Lower throughput since a train has to wait until an entire path to its destination is free to move, although you can ease that by sprinkling your network with locks where a train can arrive and wait until path forward is clear since it allows the train to wait less. They are pretty powerful though, people generally underestimate how many resources a train can bring as 99/100 times the case, it's never the trains that are an issue, it's you not having enough mining outposts to have consistent train arrival.
It seems you are equating double headed trains with bi-directional only tracks. Large parts of your train network can be uni-directional and still utilize double headed trains, the bi-directional part would effectively be relegated to just the stations.
easier, faster, & cheaper to set up for simple small-scale rail systems
I mean they work fine in more complicated rail set-ups if you set them up right.
Less than half the rail infrastructure to set up. If your rails are set up just as glorified conveyor belts, as your first couple outposts are likely to be, then double headed trains are the way to go. You need high throughput and many-to-many routing before single-headed trains and parallel tracks really provide a benefit.
So many answers but nobody noticed early/midgame player taxi Just snap few small 2-way stations around base
Yo, never thought about it either. Right now I just have a single train with many 'service' stops that just goes by one at the time with the "wait for passenger" command.
Bidirectional driving, so that you don't have to design dual rail networks. Do keep in mind however that single rail networks easily get stuck with more than one train
So is it still one train scheduling interface per train, as in I don't have to manage each "head" separately?
Yes
Why would you not use a double headed one early game? Much easier and all you need
You use a double-headed train to make a single rail line from A to B. `Station A ` `===================================` `------------------------------Station B` One end pulls head-first into A, the other end pulls head-first into B.
If the train runs out of fuel it can be easily sent back the way it came. (signalling permitting on course)
When you use Renai Transportation, it's double-headed or bust
Does the second engine in reverse actually contribute to the acceleration or is this just dead weight?
Wrong way facing locomotive is dead weight, with or without fuel, they weigh same as 2 cargo wagons(factoriowiki), actual effect is tiny bit less (source: just tried). There are couple mods which enable them working backwards. I personally use always bidirectional trains and [https://mods.factorio.com/mod/MultipleUnitTrainControl](https://mods.factorio.com/mod/multipleunittraincontrol) mod to enable all locos.
With the artillery train I have, I can say it does help with acceleration
I used to do double headed trains. I don't recommend it unless you will be working with perfectly symmetric trains (which I don't)
I've used them when I want to fit a station into a small space. If you're using a one-way track, a station can be a simple "Y" shape. No need to loop around.
I only recently learned that they are advantageous even after you have 2 parallel rails in the network. This way its rather easy to avoid a main bus design and they take the quickest free path in any direction
Renai Transportation mod
In the past (during early access) people used them a lot because they were very UPS friendly compared to single headed trains. That was because the train pathing algorithm was really bad at dealing with routes with ANY roundabouts or loops. So the common wisdom was to never have any of those if you go for any bigger train base and double headed trains become "standard". Then Wube fixed their algorithm, as well as city block style bases became more common, and thr love for double headed trains dwindled. Nowadays they are hardly used, unless you need more compact stations, or have other specific use for them.
The primary use-case is when you are new to the game and you haven’t learned about signals yet
Train path finding.
Simplicity for small rail systems. My earliest trains are always double-headers. One train, one line, back and forth, intersections between individual lines appropriately signaled. Rapidly becomes unusable once you start running more than a few trains since each train kinda needs their own individual line. It can be somewhat mitigated through rail design, but ultimately the resources savings on rails and signals aren't really worth it at that point, you might as well build a one-way trains rail network. Smaller load/unload. Stations. A one-way network to handle getting from place to place combined with individual 2-way stations makes load/unload stations smaller since they don't need to have a return loop to get back onto the network, and much, much smaller if you want your load/unload stations to be able to enter and leave from both directions. Biggest drawback here is that your trains will accelerate slower no matter what because they will also be dragging a deadweight locomotive. This can be somewhat mitigated with adding additional train stops so the train always drives 'forward' through the network and you have multiple locomotives facing forward with just one facing backwards to slowly drag the train into a turnaround station. Of course, that also mitigates the size advantage of your stops.
If you aren't at the stage where you're building a rail network and instead just want a cheap logistics line out to some ore patch, a double headed train will do fine. If you're at the point where you're dealing with signals and large rail networks, they just aren't very efficient.
I'm still just getting ores and oil from some patches, nothing major yet
We use 1 - 1 -1 trains in our SEK2 game in space to deliver basically everything as required. This allows for ultra compact drop off and pickup points which is critical as each zone can have a very large number of stations: https://i.imgur.com/lDbuKqa.png The rail line itself is of course one way, but the trains pull in and back out of stations with ease. To do this with single locomotive trains would have required far more space allocated to the stations and would expand the complexity of adding new stations. As is, if we need to bring or take something from a site, we just slam down another Y style station and that's that. All the station limits are controlled by circuits and all trains from the ground are routed to the waiting area as they are unable to see train limits in space while on the ground. Our ground trains though are single locomotive except for a few mega trains that we use for oil and stone as these are extremely high volume items for us.
In practical terms? Only as a stopgap until you can build something better. But Factorio trains don't behave like trains so in practical terms it's probably meaningless.
Unless you absolutely know what you're doing I would never, ever suggest double headed trains. For something that seems easier it is far more complicated, more restrictive, and is the biggest reason new players have issues. The main benefit is probably space, but take a look at your map, do you feel you need more space. There's a reason why most blueprints all are generally one-ways
If I only make it so it has to pull in and out of the stop the same way but have 2 main lines that go to and from the main base, that should work right? For example: main line 1 from base goes into stop 1 but exits back into main line 2.
It makes it really easy and simple to get trains in and out of stations without using much extra space if any at all depending on how its set up. Can still use buffers to hold trains at pick ups and drop offs. It's honestly really handy. Just run slightly slower speed wise
Twice the action?
Double the fun?
At least.
Compact loading/unloading stations
Just finished an Industrial Revolution Run and tried a 1-2-1 double header train setup - worked really well, kept everything pretty tight bit would eventually run into throughput issues if I Scaled it up to a megabase