Managing cargo at a transfer hub

[feroxium]

Hey all!
(playing 112.2 r6390M, with pak128 incl. most of the snfos mlm-maglev & subway station stuff)

After setting up some passenger buslines, I have built a very simple (and profitable ) freight train system:

• A train from a sand pit brings sand to a station in the middle of the route over a single rail.
• The middle station is right next to a coal mine
• The middle station is one single station, with two unconnected platforms
• Another train (twice as big) brings coal and sand to a glass smelter.

So:
Sand----->Coal----->Glass,
with sand being "consolidated" with the coal at the coal mine.

The problem:

The second train seems to grab random amounts of coal & sand. Sometimes there is a ton of sand stored at the glass smelter and it keeps waiting for coal, and vice versa. It does seem to always get both in one trip, but the amounts seem a bit random. The freight carts for sand and coal are shared (bulk goods), so I can't just make a train with 2 types of carts. Is there any way to regulate the cargo a bit more, apart from making a completely separate track from the sand pit?

Thanks in advance!

[Ters]

You don't need a separate track, but you might need to tweak how you use the trains. I'm not quite sure what your problem exactly is, but having the second train twice as big as the first means that it takes two trips by the first train to fill up the second when there is no or little coal to transport from mine to smelter.

Some rather generic alternatives are:

   
• Let the sand train run all the way to the smelter, but sharing the same track with the coal train. Time for some signals, if you haven't used them already.
• Reduce the capacity of the second train to the same as the first, but keep the capacity of the line the same by either having twice as many trains on it, or perhaps the second leg is just half as long as the first or twice as fast so that the second train can make two trips while the first can only make one. This likely also means use of signals.
• Have the second train not wait for a full load, just 50-75 %. This might however ruin it's profitability.

[feroxium]

Thanks for the response!

The tracks are all single, with one train going back and forth. I didn't want to extend the sand line to the glass plant, or use multiple trains, because i'm still a bit low on funds, and the operational profit is a bit uncertain as well.

But your response gives me more insight in the options, so I think i'll just accept the problems for now untill I have a bit more funds/income and have the ability to optimize. Or i'll sell the first train, and let the second one alternate between sand/coal.

[feroxium]

Hmm, I seem to have run into a similar problem yet again.

Transporting glass (and grain of course) to a brewery, which works fine!
Now I was thinking, well, that train with the "piece goods" wagons bringing glass to the brewery can just as well transport the beer back, as they use the same wagons as well, and there is a town with a supermarket pretty close to the glass factory. Way more efficient than having an empty train going back.

But if I put it on "wait for 100% load", it just waits, it doesn't take the beer back to the glass mill. Is there anything I can do about that?

Nevermind. I have to remind myself it works different from openTTD with its explicit load/unload/transfer orders... I finished the complete line to the supermarket with a small freight boat, and once the path was 100% complete, it magically started working!

[Ters]

My experience is that it is difficult having freight trains which carry goods both ways wait for a load. Especially when the goods carried in one direction is used to produce the goods going in the other. Sooner or later, it locks up because the train is waiting forever for goods that won't be produced until the train has transported more goods from the other station. One can try and tweak the the max waiting time and the load percent, but both can lead to low profits, perhaps even trains operating at a loss.