Experiments with a line using multiple platforms (doubling up)

[theSeb]

I have spent some time experimenting with getting train lines to use multiple platforms for loading and unloading. Basically in theory this should allow you to potentially double the throughput at the line, since each alternating train should stop at a different platform to load and unload, thus alleviating waiting times just outside the station on busy routes. The way this works if instead of setting up a route from A1>B1 (where A and B are stations and 1 and 2 are platforms) you set up the route with 4 destinations like this A1>B1>A2>B2 or similar.

In terms of the trains these routes work well. Trains quickly go into a nice cadence and multiple trains go in and leave at the same time. With a set up like this you can potentially have two trains in the station and two trains just outside waiting to come in, which helps to alleviate congestion down the line on busy railways. Of course you could have set up two lines like A1>B1 and A2>B2 but I found that using that approach line would get the cargo and the other would get very little. Thus I was hoping that doubling up a single line would potentially solve that problem.

This works beautifully for stations where trains are unloading only. Unfortunately in terms of how the cargo is split at stations where goods need to be picked up I am having mixed success. On some lines the goods get split up, but not evenly and on others only one platform is favoured. I am still trying to figure out why that is, but I suspect it's something to do with the fact that the one portion of the journey is slightly longer than the other? What I mean is that on a route A1>B1>A2>B2, the A2>B2 portion might be a big longer by a few metres so all of the stuff goes into platform B1, thus making the A2>B2 route superfluous.

If you have experimented with set ups like these, it would be great to hear your thoughts and experience.

Kind of working here at this through station, but one platform is getting far more attention than the other. The food train stops at two platforms on the way to the food processing line.

https://steamcommunity.com/sharedfiles/filedetails/?id=1403865281

One possible example of how to set up a line like this in terms of the track layout

https://steamcommunity.com/sharedfiles/filedetails/?id=1403865410

Two trains on the same line pulling out of the station on two different platforms, after filling up (in theory, since only platform is getting crude on this route)

https://steamcommunity.com/sharedfiles/filedetails/?id=1403865517
One train pulling in to its own platform and another train on the same line leaving. If only cargo was getting split evenly, this would really give a massive boost to how much stuff you can move in a year.
https://steamcommunity.com/sharedfiles/filedetails/?id=1403865155

On the general topic of line routing… here I am experimenting with a three track set up (because I really wish the game would work well with just two tracks and hate quad tracking (or more) everything, so I thought I would try a three track layout)

https://steamcommunity.com/sharedfiles/filedetails/?id=1403865325

[chrisasnyder]

I've played with this idea a few times since TpF was released. It used to work better than it does now and the reason is interleaving which you don't mention. Interleaving is where you force every other train to be heading to the opposite platform. When interleaved two consecutive trains use different platforms. In the past, it was simple enough to select every other train and hit reverse. However, since the fall patch where they "imporved path finding" where trains would automatically head to stop1 when they encounter a problem, getting interleaving setup and not having it broken by the path finding is just to tedious. (every time you make a track modification on the line the interleaving gets reset)

I suspect the problem you have with cargo not splitting platforms is frequency for use on each platform isn't balanced. Even one train out of interleaving order will cause one platform to see a higher frequency for a while then the other. This causes a swing effect for which platorm is moving faster.

I also think you are right in small cost difference causes one platform to be favored more than the other.

The other issue I've seen with this approach is hitting the cap for the amount of waiting cargo an industry will tolerate. This is because with 2 platforms filling with cargo, an arriving train only clears one platform, and the build up on the second platform eventually causes the industry to halt prodcution. This can be minimized by using the wait for full, which will work when the industry is running at max output, but anything that causes the production to fluctuate will create problems of stalled trains since now 2 platforms have waiting trains getting a slow trickle as it ramps back up.

For me, the micromanagement of the interleaving and the sensitiviy to fluctuations make this too much trouble than it's worth.

I've found that a well constructed pull through station layout will allow a single line to handle the output from just shy of 4 industries running at maximum output of the same cargo type. This will drop significatly if there are mixed cargo types that are not split evenly. At or above 4 max industry output the platform fills up faster than a train can leave and the next pull in.

[Vimpster]

I experimented with this some time ago and had similar findings. Being unable to get balanced distribution on the platforms. Though sometimes there is just no other way to increase the volume of transport and so despite it's inefficiencies it can still be useful on occasion. I actually had to do this in my current game using ships. There simply was no more room to add more ships without queueing occuring. So I doubled the orders and then doubled the ships untill the next size ship became available.

I haven't really tried it with passengers though. So perhaps, going by your findings, there is some promise with that. But I would be curious of your setup. The thing is you can double back on a station, which I'm sure we all have done when connecting 3 or more stations with a single line. But when the middle station is a terminal station than you can essentially have something that looks the same as a double ordered type of line when really it isn't. Here is an example of what I mean: https://steamcommunity.com/sharedfiles/filedetails/?id=883319116

[theSeb]

I am only doing this for cargo by the way

[BGR]

As long as 1 raw materials supplier is connected to 1 finished goods manufacturer to supply 1 city the only entity that has control of it's production is the raw materials supplier. That raw materials supplier will flood us with more product than we have setup our vehicles to transport in one delivery cycle and more than our 1 city needs in 1 year. Thankfully this is not a problem because when the raw materials supplier throws a hissy fit and shuts down because we are not delivering more material than our finished goods manufacturer and our 1 city needs there is so much available raw material that it bridges the gap until production resumes.

The finished goods manufacturer is up to this point well behaved and under our control because it is limited by the quantity of raw materials we deliver to it. But the moment a 2nd city is connected we relinquish some of that control and give the finished goods manufacturer the ability to chose how much of the raw materials we supply will be used for each city and that is when things can go wrong.

The finished goods manufacturer may decide and often does decide to manufacture more product for one city at the expense of the other and not divide the raw materials we deliver according to the demands of the two cities. It does not seem to care that the vehicle capacity that we have provided will deliver only what the 2 cities yearly demand requires. It also does not seem to care that it is starving one city of product and manufacturing more product for the other city than it requires or that our vehicles are setup to deliver. It may even starve the older city even though that city was supplied by it first and as a result has a larger demand for it's product.

[theSeb]

So I've been running this on for a bit and it seems to be working for some of the routes at least.

Munich supply route is looking good
https://steamcommunity.com/sharedfiles/filedetails/?id=1404689863

...and so is the Berlin one
https://steamcommunity.com/sharedfiles/filedetails/?id=1404689912

[theSeb]

Having played on some more pretty much all the freight routes are splitting the cargo evenly. Great success.