What type of train network to build around? (train size)

[BLuehasia]

so i been seeing people talk about train networks build around the size of your train and if a locomotive is on each size.

is this more personal choice?

pros and cons?

the most i ever down was adding to my network was one locomotive and 4 wagons.

[Aeternus]

It depends on the scale of your network, and can be important for the type and size of crossings you have to make, and the size/layout of the stations. I typically run 2-4 (locs/wagons) unidirectional trains for heavy cargo, 1-2-1 for distant mining outposts, 1-2 for fluid transfer, and some smaller trains for low volume traffic (such as acid to uranium mines). It is a personal preference you have to decide for yourself. Bigger trains means fewer in transit, which can help with congestion. More locomotives in the trains movement direction means faster accelleration.

[BLuehasia]

im really wanting to go larger now, i have a train network that has 30 trains on it from one wagon to 4 wagons,

the network is a 2-way system, and its just jam packed, im moving in my game to a new location in my world and will start over with a 4 lane track and wondering if i should build it with only a locomotive on one side, or one on each side.

[Dimanper]

It depends on the scale of your network, and can be important for the type and size of crossings you have to make, and the size/layout of the stations. I typically run 2-4 (locs/wagons) unidirectional trains for heavy cargo, 1-2-1 for distant mining outposts, 1-2 for fluid transfer, and some smaller trains for low volume traffic (such as acid to uranium mines). It is a personal preference you have to decide for yourself. Bigger trains means fewer in transit, which can help with congestion. More locomotives in the trains movement direction means faster accelleration.

1-2 for fluid transfer? Isn't fluid wagon weights three times as much as cargo wagon? I'm running 3-2 trains with fluid wagons just to keep that sweet 1 locomotive to 2 cargo wagons ratio, otherwise fluid wagon trains would just slow down trains with cargo wagons (2-4).

[Mehve]

If you build a network for certain train size, but then decide you want to go bigger, you can run into a lot of problems with waiting bays, close intersections, etc. So it's good to have an end-game size in mind when you start laying rail seriously.

[AndrewIRL]

wondering if i should build it with only a locomotive on one side, or one on each side.

Edit: Updated since one Loco = 2xCargo as pointed out by Dimanper

Source

In the game code, locomotives have a weight of 2000, and cargo wagons 1000 regardless of what's IN either. Every unit has a "friction" value, and I believe its the same for both. Power-to-weight ratio is not the sole determinate to acceleration and top-speed, as the added friction from length will reduce both of those values. Turns have no effect on train speed or acceleration.

viewtopic.php?f=5&t=17639

The ratio of loco/wagon will affect top speed and a loco at the end of the train like L-CCCC-L counts as an extra wagon getting pulled.
https://www.reddit.com/r/factorio/comme ... comotives/

Two locos and five cargo:

Code: Select all

LL-CCCCC,  ratio = 2.5, top speed = 239.4
L-CCCCC-L, ratio = 7  , top speed = 119.6

Two locos and four cargo:

Code: Select all

LL-CCCC,  ratio = 2, top speed = 259.2
L-CCCC-L, ratio = 6, top speed = 134.6

The convenience of dual head costs about 48% in top speed.

You cannot get a ratio of 2 on dual head.
2.50: LL-C-LL
2.33: LLL-C-LLL
2.25: LLLL-C-LLLL

I think you can compensate with solid or rocket fuel. Haven't tried.

Lower speeds means less throughput => more trains needed => more congestion
but wait, there's more
Lower speeds means more time between stations per train => more congestion

So you get a double whammy congestion effect. If the train is twice as slow then it blocks an intersection or a rail section for twice as long, doubling congestion. If it twice as slow then it only delivers good at half the rate so you need two - double the congestion.

All told your congestion is quadrupled when train speed is halved. Fast trains FTW.

[Dimanper]

wondering if i should build it with only a locomotive on one side, or one on each side.

The ratio of loco/wagon will affect top speed and a loco at the end of the train like L-CCCC-L counts as an extra wagon getting pulled.
https://www.reddit.com/r/factorio/comme ... comotives/

Two locos and five cargo:

Code: Select all

LL-CCCCC,  ratio = 2.5, top speed = 239.4
L-CCCCC-L, ratio = 6  , top speed = 134.6

Two locos and four cargo:

Code: Select all

LL-CCCC,  ratio = 2, top speed = 259.2
L-CCCC-L, ratio = 5, top speed = 153.8

The convenience of dual head costs about 40% in top speed.

To get a ratio of 2 on a dual head you need to match cargo wagon count to loco count on each end LL-CC-LL or LLL-CCC-LLL making the trains much longer.
...

You can't get ratio of 2 with double header trains, since for every locomotive you add on one side you need to attach another locomotive on the other side to pull it in opposite direction and keep ratio of 2.
LL-CC-LL = LL-CCCCCC, wich has ratio of 3.

[saturn7]

To begin I use double headed trains with 2 wagons (1-2-1). They are easy to set up and have enough capacity for short routes, and it's easy to run different trains for iron/copper/oil.

Once I get outposts farther away and a higher resource demand (say >5k iron/minute) and robots sort the ores, I will build a new train network for one-way trains (while leaving the old trains running until the resources are depleted). The best one-way choice I found was 2 locomotives and 4 wagons each (2-4). They have a great acceleration, good throughput, and still have a reasonable length so stations are easy to design.

One I need really high throughput (>100K/minute), I might consider building local hubs and use even longer trains to transport the resources between the hubs.

[AndrewIRL]

You can't get ratio of 2 with double header trains, since for every locomotive you add on one side you need to attach another locomotive on the other side to pull it in opposite direction and keep ratio of 2.
LL-CC-LL = LL-CCCCCC, wich has ratio of 3.

Went searching for a source on this and found:

In the game code, locomotives have a weight of 2000, and cargo wagons 1000 regardless of what's IN either. Every unit has a "friction" value, and I believe its the same for both. Power-to-weight ratio is not the sole determinate to acceleration and top-speed, as the added friction from length will reduce both of those values. Turns have no effect on train speed or acceleration.

viewtopic.php?f=5&t=17639

Making you right and me wrong. I've updated my post to account for the L = CC weight difference.

[Serenity]

You can start with setting things up for L-CC-L trains. That's fine for the start. But try to space things so stations and waiting yards can be extended to L-CCCC-L when needed

[BLuehasia]

*head spins*