Train/Ore balancing

[Melter]

Hi all

Im new to grand scale smelting and trains. I was wondering, when I setup a remote ore mining operation, is it a problem to train in enough ore to keep up with large numbers of smelters? I know this seems a bit of a open ended question, but I'm curious as to whether I should be aware of any guidelines for setting up loading/unloading before setting up my stations. I have visions of large holes in the compression and my smelters sitting idle... Thanks for any advice : )

[Nich]

You will need multiple mines delivering ore. Just remember if you have 100 smelters you will need 110ish? miners (.525 items/s vs .579 items sec feel free to check my math) and that assumes none of the ore bottle necks. 2 trains per route is nice because 1 can load while another is unloading. 3 if the route is really long.

Oh and don't forget parking spots as your smelters back up so will your trains that are delivering ore. Parking at ore pick up is not quite as important but as the mines die out you will have to divert another train elsewhere or build parking at some point the mines will not be able to keep up with trains.

I am a train noob so take my advice with a grain of salt.

[urza99814]

I find one train per resource is plenty unless you're building a HUGE base. The important part is keeping it running.

I usually have a line of stack inserters and steel chests beside each train stop. So the cargo wagons unload in seconds into the chests, and then the chests take time to empty onto belts while the train is getting the next load. Do the same in reverse for mining so the miners never jam, they fill boxes to fill the train. Just set a maximum time limit (i do 30-60 seconds) so that if you do start to run out from the mines the train will keep moving what you have left until you build a new mine.

The problem I always have is getting the mine to produce enough to fill the train. Even a single cargo wagon moves a hell of a lot if it's making a round trip every few seconds! Often I'll have one train stop at two or three mining outposts before it returns to base.

[Melter]

Ok, thanks for the tips, so the train being able to keep up with volume isn't really a problem then... Im a bit of a noob at all this and just looking at the compressed belts running to the smelters it looks like a LOT of ore that seems unreasonable for a train to keep up with.

[urza99814]

Compressed blue belt carries 40 items per second
https://wiki.factorio.com/Express_transport_belt

Train cargo wagon carries 40 stacks, and your ores are stacks of 50
https://wiki.factorio.com/index.php?title=Cargo_wagon

So a train with two wagons can keep a blue belt full if it returns every hundred seconds. Loading/unloading shouldn't be more than 30 seconds total, giving 70 left, which would work out to a theoretical maximum distance of 2100 game squares before you really need more trains or wagons.
https://www.reddit.com/r/factorio/comme ... xperiment/

Belts are slower than they look!

[Melter]

Wow, thanks Urza, that is handy info you've put together there, clearly it isn't as difficult to supply as I thought : )

[Nich]

You should probably define a "large" number of smelters. To some people 48 is large and to others 480 is large. I am pretty sure 1 wagon with 24 stack inserters and buffer chests unloading can support 4 blue belts. You would need a wagon every 12.5 seconds and you would only have 5-6 seconds to get the empty train out of the station and a new train into the station

The real bottle neck with trains is loading/unloading.

[Melter]

You should probably define a "large" number of smelters. To some people 48 is large and to others 480 is large. I am pretty sure 1 wagon with 24 stack inserters and buffer chests unloading can support 4 blue belts. You would need a wagon every 12.5 seconds and you would only have 5-6 seconds to get the empty train out of the station and a new train into the station

The real bottle neck with trains is loading/unloading.

Good point, I would imagine at least 140, probably more, maybe 210, and I imagine that I would load/unload at 2 points to start with and keep adding trains till I get to keep the belts full : )

[Nich]

so is it 70 smelters/ blue belt? (40 items/s *3.5 s/item / 2 crafting speed) personally I would do 1 wagon per belt. Then you can unload from one side and only need 4 or 8 stack inserters (depending if you want to buffer or not). 3-4 wagon trains seem pretty nice to work with. lthough that is assuming no productivity/speed mods.

I have played around with 1, 2, and 4 wagon trains lightly. I have not actually made a working base because I keep wanting to try something else. Up next are 8-16 wagon trains which I have not seen anyone do. I am guessing to are so long / unwieldy they make planning/building a pain

[Melter]

Yes, 70 smelters per lane, it's all new to me all this outpost mining mullarcky. I've seen youtube vids of ppl transporting huge quantities of ore, with monstrous loading and unloading areas, it rather scared me that I might get a bit out of my depth..

[Nich]

HAHA it is a game you cant get out of your depth as long as you are having fun. I would make sure I have power armor mkII, 3-6 shields mkII, fusion power and roboports though before I do too much production. Dont want to bump up the evolution too much and have to fight behemoths without those.

After my last 4 hour clearing expidition doubled the size of my base I might start just doing outposts in the future.

[impetus maximus]

to make sure your trains transfer material as fast as possible, make sure buffer chests loading/unloading trains are balanced.
having only a few chests gobble up/drop all the material slows loading/unloading of trains.

some will use a metric ton of splitters, but there is a better way!

say you have 12 chests for LOADING two cargo wagons from your ore outpost. connect all the chests together with a green wire.
connect the last chest to the input of an arithmetic combinator set to 'ore / -12, output ore.
now run a green wire from the output of the arithmetic combinator to all the fast inserters loading the chests from the belt.
set the inserters to activate if ore < 1. (you can set it to 2 or 3 if you have non-stack inserter bonus 1 or 2)
now connect a SINGLE RED wire from each inserter to only the chest it's loading.

balanced.chests.png (333.39 KiB) Viewed 15333 times

you can do the same for unloading (onto the belt) but set the inserters to enable if ore < -1. this number must be negative.
if you use 0 there is possibility of all the chests to have an = amount, they they will stop unloading.

cheers

[Melter]

to make sure your trains transfer material as fast as possible, make sure buffer chests loading/unloading trains are balanced.
having only a few chests gobble up/drop all the material slows loading/unloading of trains.

some will use a metric ton of splitters, but there is a better way!

say you have 12 chests for LOADING two cargo wagons from your ore outpost. connect all the chests together with a green wire.
connect the last chest to the input of an arithmatic combinator set to 'ore / -12, output ore.
now run a green wire from the output of the arithmatic combinator to all the fast inserters loading the chests from the belt.
set the inserters to activate if ore < 1. (you can set it to 2 or 3 if you have non-stack inserter bonus 1 or 2)
now connect a SINGLE RED wire from each inserter to only the chest it's loading.

balanced.chests.png

you can do the same for unloading (onto the belt) but set the inserters to enable if ore < -1. this number must be negative.
if you use 0 there is possibility of all the chests to have an = amount, they they will stop unloading.

cheers

This looks absolutely genius, but have read it 23 times so far and still can't say I'm totally understanding the probable result : | Does this basically mean that the inserters will stutter collect to ensure that the the chests are maintained equally? And for offloading, you would use the same setup to output from the chests to belts right? Not from the wagon, I guess a standard stack inserter is fine for that job?

[impetus maximus]

sorry. i should have explained that.
when loading chests, if the chest the inserter is loading is above average (of all the chests) it won't load.
if it's average or below, it will. it keeps the number of ore in all the chests the same (+/- 1-3)

for unloading it keeps chests from hogging the belt.

it keeps the ore flowing though all the inserters without favoring or neglecting any.
this increases throughput.

[Miravlix]

sorry. i should have explained that.
when loading chests, if the chest the inserter is loading is above average (of all the chests) it won't load.
if it's average or below, it will. it keeps the number of ore in all the chests the same (+/- 1-3)

for unloading it keeps chests from hogging the belt.

it keeps the ore flowing though all the inserters without favoring or neglecting any.
this increases throughput.

Throughput is gained/lost due to the amount of items that can move through the design at full capacity, if the station unloads unevenly from chest, that means the station is not unloading at maximum throughput but is being limited by how much the belt can move.

This result in needing to balance chest, so you don't end up with empty chest, as an empty chest will result in lost throughput if the number of chest that is empty is higher than the minimum needed to support filling the belt.

So I have to call it alternative fact that is result in increased throughput. It can prevent losing throughput if your station is badly designed.

Also you should move to the new design, just link inserters (That drop onto the belt), set it to read hand content and "hold" (Not pulse), then tell them they should only grab new items if everything (Or is it anything, the red one) = 0. Super simple, balanced chest unloading.

[Melter]

thank you so much for the help, it will make it even more interesting to get things all sorted! All this combinator stuff is a bit of a test for me at the moment, but it looks like a good time to learn.. thanks for all the advice

[impetus maximus]

Also you should move to the new design, just link inserters (That drop onto the belt), set it to read hand content and "hold" (Not pulse), then tell them they should only grab new items if everything (Or is it anything, the red one) = 0. Super simple, balanced chest unloading.

that does work and gets the job done. however the chests can, over time become unbalanced.
i'm guessing it has something to do with tick delays. the new design is good enough for service for sure.
i just prefer the arithmetic way.

[edit] your welcome. enjoy

[Nich]

HAHA the balance loading/unloading debate again :p

It is snake oil I tell ya!!!!!

In a factory there are only 2 likely options
1. Supply > Demand
2. Supply < Demand

On very rare and specific occasions does Supply = Demand

In fact because miners decay it is most likely that you will start with case 1 hit and decay into case 2. Yes this means at some point supply will = demand but this will be a realitivly very short period.

At an unloading station
In case 1 the belt will back up causing chests to back up causing train to wait for room to unload
In case 2 the chests will always be empty when train arrives.

At a loading station
In case 1 chests will top off and miners will shut down
In case 2 chests will always empty after train arrives and then train will have to wait for miners to top it off.

[ssilk]

I want to point to a mod called "boxing". There are similars. You can put the ores into boxes, one box contains 50 ores then.

With that you can increase both: throughout of the trains/belts by factor 50 and updates per second of the game by factor 2 or 3 (less items, less CPU, but you need still to pack/unpack the boxes).
AND it changes the game-play completly, cause now you need to bring the empty boxes first. It's a logistic challenge.

EDIT: More about that topic here: viewtopic.php?f=80&t=19343

[impetus maximus]

boxing mod looks pretty darn cool. would add depth (and throughput) to trains and towns.
thanks ssilk.