Loading pattern for multiple convoys to the same destinatination.

[Venkat]

Hello,

My query is with respect to this example.

I have a coal mine and it is connected to a Steel Mill. I am running 4 train convoys to this Steel Mill. I notice that a train which is already partially loaded is not completely loaded and dispatched before the other trains are loaded. For example, TRAIN 1 is showing 79% capacity. I expect that this train is loaded till 100% and then dispatched before other trains that arrived later are loaded. In this case, all the trains are loaded simultaneously.

What is the exact behaviour in such a scenario. Can this be changed?

Regards,
Venkat

[ӔO]

Open the line management window, then click on the line that is sending coal to the steel mill.
Click on "update line" and then you will get to change the schedule. At the top of the schedule you should see a "minimum load: #". Change this to 100 for the coal station.

[DirrrtyDirk]

That still would not prevent the other trains from being loaded while the first one isn't full yet - and as far as I understood, that's the issue here.

[Isaac Eiland-Hall]

I do believe the only way to force one of several trains to load fully would be to build a system in which the trains must queue for a single station.

[Combuijs]

What is the exact behaviour in such a scenario.

I'm not sure, but I think the trains are loaded alternately. Every time there is something to load the program looks which train was loaded last time and then loads the next one. This guarantees that no train will be forgotten. So, say all trains have the same capacity and the load increases 20% every time you will get:

train 1: 0 - 20 - 20 - 40 - 40 - 60 - 60 - 80 - 80 - 100 (and away)
train 2: 0 - 00 - 20 - 20 - 40 - 40 - 60 - 60 - 80 - 080 - 100 (and away)

If one train is already 40% full and one completely empty you get:

train 1: 40 - 60 - 60 - 80 - 80 - 100 (and away)
train 2: 00 - 00 - 20 - 20 - 40 - 040 - 60 - 80 - 100 (and away)

This algorithm is for instance necessary when playing with more players. The load is then proportionally divided.

Can this be changed?

No, not to my knowledge.

[Venkat]

Ok, understood. I will have to play differently then.

Thank you all for the clarifications.

Regards,
Venkat.

[skreyola]

Perhaps there could be a simuconf.tab option (in single-player mode) to fill trains exclusively when they are over 50% (or at least for over 75%) filled? It's a pain to have a train sitting at 90%, a new train enteres the station, and then both trains are sitting there loading and not making any money.
Or just change it so that if all the available trains at a station are owned by the same player, the fullest one gets loaded first? Or gets loaded at a much higher rate than others at the station... This would even out a lot of things, including traffic and vehicle utilization, so that you don't have lines where one train is raking in 100k credits while three others are pulling in 1k. Eh? It would also help traffic in road stops with many bays, because you wouldn't have them all sitting there and then all reaching 100% at the same time and all trying to race for the exit at once!

[VS]

skreyola: If you don't let all trains load but queue them before station, they will all get even profits as they'll have to wait for each other.

[Venkat]

Hi,

Further to this, what is the solution when each convoy is 8 tiles long and there are 4 such convoys. In such a case, all these convoys occupy a minimum of 8X4=32 tiles. for a 256x256 tiles this is a good chunk of the available real estate....

Venkat.

[mobo]

Well queue them all in front of the station - as said - and if you see there is always 2 or more waiting, then you simply have too many trains, and can sell some.

edit: Actually i dont quite get it, seems like you misunderstood something. By queuing we mean that the trains wait on the track between coalmine and steel mill, this track needs to be built anyway, so this part of real estate is already lost. Of course you need a double track, or at least some short pieces of double track in between so the trains cann pass each other. But you already have built that too, if you successfully run 4 trains on one way/connection.

[Venkat]

The suggestion provided by mobo is not applicable for all scenarios. What happens in the case that the good has to be shipped to the other end of a 1024x1024 map? Is there a better way to keep the supply chain running for that factory? You could use air for transport, however, the largest cargo that a plane can take is 25 crates of boxed good. There is no provision for transporting bulk cargo other than rail over large distances. Ships are generally slow for the purpose.

A question I always wanted to ask other simutrans players. Do you have arbitrary length train convoys or have fixed length ones. I use the fixed length of 8 tiles for all my trains (passengers as well as goods.)

Regards,
Venkat.

Regards,
Venkat.

[Combuijs]

The suggestion provided by mobo is not applicable for all scenarios.

Oh yes, it is!!! Where ever your train is waiting, it is occupying a number of tiles. That can be in a station, that can be waiting before the station, but it always uses the same amount of space.

Do you have arbitrary length train convoys or have fixed length ones

Fixed length, in my case 6. Fixed length because it is easier to mix train traffic on a track (block size) or platform (station size). In real life freight trains are much longer than passenger trains, so you might use two sizes that are multiples of each other (for instance 6 and 12).

[VS]

I'll illustrate - with illustrations Both examples are refineries served mostly by trains.


First example: Approach through tunnel under the refinery. Then, the track splits into 3 branches. I think the one at the bottom was for unloading oil, because it has shortest queueing track in front of it - looks like only 2 trains can wait. The other two platforms are for loading plastics and gasoline, and both have a longer queueing track in front - 5 and 6 trains can wait.


Second example - approach from the left, queueing around the refinery. Oil is supplied by another train on the right side outside screen.

Is this still too big?

[mobo]

How illuster* ! 

*creepy old fashioned and not very common german word for funny/entertaining

[skreyola]

skreyola: If you don't let all trains load but queue them before station, they will all get even profits as they'll have to wait for each other.

True.
However, they don't complain of being stuck if they're on a platform. I know, better manage your capacity, but with intermediary factories, there can be a lot of wait and hurry-up, so you need more capacity at peak than at other times.
Also, I just like building big stations.

I know not everyone likes this scheme, but couldn't it be an option in single-player games so the player can choose which model to use?

@mobo: Doing so limits your ability to build networks where multiple lines use the same trunk track.

[inkelyad]

However, they don't complain of being stuck if they're on a platform.

So, we just need a way to build very cheap "waiting station".

[nitromefan]

To prevent this problem

Option 1 : Make the trains Que for the station
Option 2 : Have one platform per train.

Both of these will work Venkat

[Stubbsy]

So, we just need a way to build very cheap "waiting station".

Well would something like this work...

You make a station to the side of it and make the trains stop there, have choose-signals at the start of the station of course, then have signals at the end. Then all of the stations there lead off onto one track which leads straight to the Station next to the factory..

[Isaac Eiland-Hall]

Thank you, Stubbsy, I'm completely stealing that idea - and I'm going to use it for truck convoys, too.

[Stubbsy]

hehe  always here to give out my ideas

[Isaac Eiland-Hall]

Please note that nitromefan has been changed to a "Lounger"; therefore, any followups for them from this thread should be directed there.

For more information, see here: http://forum.simutrans.com/index.php?topic=5620.0

If this post is a double-post, it is intentional.

Please continue the thread. If you have any questions about this post, please start a new topic in the Help Requests board.

[Stubbsy]

and that means? 

[Isaac Eiland-Hall]

http://forum.simutrans.com/index.php?topic=5620.0

[Stubbsy]

ahhh fair do's xD

[skreyola]

So, we just need a way to build very cheap "waiting station".

No. This will not work. They will report stuck unless they are in their own destination waiting. But if they're in that station, they're going to sap some of the load. Even if you put the station in their line, they will still report stuck, because they won't be waiting in the waiting station but in whatever block ends beyond it.
I think that an acceptable solution would be to make it so that if two trains are bound for the same destination with the same cargo type(s), and one of the trains is at 75% or more, and the other is at 10% or less, the stationmaster will only load the 75% full train until it can leave. I know, any changes to the loading code would be difficult, but the loading does seem a little bit funky in game. Especially when an empty train comes in and keeps a train from getting the last 5% needed to go and make money.

[inkelyad]

But if they're in that station, they're going to sap some of the load.

'Waiting station' must be just for waiting. No storage capacity, no goods transfer, really cheap.

[Isaac Eiland-Hall]

"really cheap" is a problem - make a nice long station, then add one warehouse, and you have a too-cheap goods station

[skreyola]

'Waiting station' must be just for waiting. No storage capacity, no goods transfer, really cheap.

I meant the main station, when I said they would sap good from that station.
I understood the concept of a waiting station, but then you either have the train stopping there and then proceeding on to the next signal, or you have your main station sitting empty while the train 'waits' in the waiting station, and that means goods are piling up, which is why you had more than the absolute minimum number of trains in the first place.