Optimal train lengths in 0.16

[Avezo]

I'm preparing to upgrade my factory and for that I need larger trains. The info I found so far was either conflicting or outdated.

I'm interested both in double headed trains and single-headed and how big they need to be to run over behemoths freely.

The only thing that seems to be consistent among what I found was that 1 engine at the back in two-headed trains counts as 2 wagons.

[Frightning]

I'm preparing to upgrade my factory and for that I need larger trains. The info I found so far was either conflicting or outdated.

I'm interested both in double headed trains and single-headed and how big they need to be to run over behemoths freely.

The only thing that seems to be consistent among what I found was that 1 engine at the back in two-headed trains counts as 2 wagons.

Choice of fuel matters, If you know what the top speed and acceleration modifiers for the fuel type you intend to use are, then you can probably modify the math I did in viewtopic.php?f=18&t=47461&p=273819 to account for it and get the optimal locos-to-wagons ratio for your chosen fuel type.

[darkfrei]

Short trains for short distances, long trains for long distances. And double unloading stations instead of waiting buffer.

[Avezo]

I'm preparing to upgrade my factory and for that I need larger trains. The info I found so far was either conflicting or outdated.

I'm interested both in double headed trains and single-headed and how big they need to be to run over behemoths freely.

The only thing that seems to be consistent among what I found was that 1 engine at the back in two-headed trains counts as 2 wagons.

Choice of fuel matters, If you know what the top speed and acceleration modifiers for the fuel type you intend to use are, then you can probably modify the math I did in viewtopic.php?f=18&t=47461&p=273819 to account for it and get the optimal locos-to-wagons ratio for your chosen fuel type.

How is that modifier applied? If it says that nuclear fuel for trains give 115% speed where exactly does that apply in that math?
Is it that

Train speed maximum:
1.2 tiles/tick=72 tiles/sec=259.2 km/h

Should be multiplied 1.2 x 1.15 and taken as new maximum speed in further calculations?

[Frightning]

I'm preparing to upgrade my factory and for that I need larger trains. The info I found so far was either conflicting or outdated.

I'm interested both in double headed trains and single-headed and how big they need to be to run over behemoths freely.

The only thing that seems to be consistent among what I found was that 1 engine at the back in two-headed trains counts as 2 wagons.

Choice of fuel matters, If you know what the top speed and acceleration modifiers for the fuel type you intend to use are, then you can probably modify the math I did in viewtopic.php?f=18&t=47461&p=273819 to account for it and get the optimal locos-to-wagons ratio for your chosen fuel type.

How is that modifier applied? If it says that nuclear fuel for trains give 115% speed where exactly does that apply in that math?
Is it that

Train speed maximum:
1.2 tiles/tick=72 tiles/sec=259.2 km/h

Should be multiplied 1.2 x 1.15 and taken as new maximum speed in further calculations?

I am pretty sure that's correct for speed, the acceleration modifier I am less sure of. I think it modifies the max power variable (which is covered in another post I referenced in my original post in the other thread). So I'd have go back and re-formulate the equations I used to get the simplified formulas for the other thread in order to handle the new fuels types. Maybe I'll dig into it at some point soon...

[Avezo]

Cool, thanks for help!

[AndrewIRL]

I'm interested both in double headed trains and single-headed and how big they need to be to run over behemoths freely.

There is no train size that can run over a behemoth that I know of. The first behemoth is killed but stops the train allowing it to get mobbed. After that the train is unable to accelerate and gets destroyed. At least that's been my experience. Extremely happy to be proven wrong, anyone?

As for train lengths, it sounds like you are driving trains into contested areas with biters around. Have you considered the new artillery wagon? It can push back the spawners from near your outposts. Warning: artillery wagons are very heavy, one artillery = 4 cargo or A=CCCC

So these two trains: LL-CCCC and LL-A will be the same speed. If you are running optimum trains as calculated by Frightning as 6 L and 13 C you could build them out as:
LLLLLL-CCCCCCCCCA
That's 6 Locos pulling 9 cargo + 1 artillery for a total cargo weight of 13, total train weight is 12+13=25.

You can also consider how fast your miners are and how distant your outposts are. One mining drill gets ore at a rate of 0.525/s. On a big ore patch, say 10x10 drills you have 100 drills and get ore at 52.5/s but you probably have some mining productivity research done, maybe level 15 for a 30% bonus. All up 68.25 ore/s without speed modules. A single cargo wagon can hold 4000 ore. So it takes 100 miners with level 15 research 4000/68.25 = 58.6 seconds to mine enough to fill one cargo wagon. Basically 1 minute per wagon. So if your roundtrip from outpost to smelter and back again, including load/unload times, is 6 minutes (1 min load, 2 min drive, 1 min unload, 2 min drive back) then a train with 6 cargo wagons would be a good fit.

A fully upgraded stack inserter moves 744 items/min. If you use 6 per cargo wagon that's 4464/min or 54 seconds to load or unload 4000 ore. It is possible to use 12 stack inserters per wagon and cut that time in half.

How far does a train travel in 1 minute? Top speed of rocket fuel trains is 298.1 km/h so with starting/stopping, traffic etc maybe they average 120 km/h. That's 2km in 1 minute, 2000 tiles or 62.5 chunks in Factorio terms. For reference a radar shows an area of 7x7 chunks.

My ore patches are usually not big enough to fit 100 miners and they are usually not a 2 minute drive away - so I use smaller trains.

[Jap2.0]

I'm interested both in double headed trains and single-headed and how big they need to be to run over behemoths freely.

There is no train size that can run over a behemoth that I know of. The first behemoth is killed but stops the train allowing it to get mobbed. After that the train is unable to accelerate and gets destroyed. At least that's been my experience. Extremely happy to be proven wrong, anyone?

They have to be quite long, however it is possible to have a very long train with enough momentum to plow through biters.
There is some discussion in this thread.

[AndrewIRL]

Extremely happy to be proven wrong, anyone?

They have to be quite long, however it is possible to have a very long train with enough momentum to plow through biters.
There is some discussion in this thread.

Aha! Proven wrong. Nice find. Total train weight of 11 needed.

These are some minimal combinations I found will democratize a behemoth biter when the train is traveling at max speed (298.1 km/h)

• 1 locomotive + 9 wagons (probably needs nuclear fuel to reach top speed)
• 2 locomotives + 7 wagons
• 2 locomotives + 3 fluid wagons

It seems you need a total train weight equivalent to 11 wagons, where wagon = 1, locomotive = 2, fluid wagon = 3, artillery wagon = 4
This is for top speed: if the train isn't up to full speed it might have inadequate momentum, it would be best to allocate sufficient safe track to reach top speed (as a side note: These numbers also work for the solid fuel top speed of 272 km/h, but if using wood/coal you'll need 12 wagon-weights)

The train does not lose speed when it wins an encounter, the game is a little indecisive on whether the locomotive takes damage or not (sometimes it doesn't) but when it does take damage it seems to suffer 53 damage meaning it can crush at least 19 Behemoths before running out of HP.