Prevent loading of cargo in a station

[williamsuarez]

Hello,
I have some unusual cargo routes, primarily for oil and coal. The issue is that a train doesn't just deliver coal to the power plant; it may also transport it back to the mine it originated from. However, there's another train at that mine transporting coal to a coking plant. So, some coal follows this route:

mine A ----(train 1 as desired)---> power plant
----(train 2 by accident)----> mine B
----(train 3 as desired)-----> coking plant

How can I prevent train 2 from loading cargo at the power plant?

[prissi]

Use seperate stations at the coal power plant. But for the transport back of the coal, you get extra money, so it may not be a bad thing.

[Octavius]

You may get paid for the additional distance (whether this is realistic is another matter), but it also takes more capacity, so you may need to invest in double track, longer stations etc. And these unusual routes tend to be somewhat unrealistic and unstable.

What I've occasionally noticed is the following. A flow of goods is sent from source to destination. But, the capacity of the connection is insufficient (I like to run my convoys at >80% of capacity), so some goods pile up at a station. This can be the pickup station or some intermediate station. This pile, which is likely to get larger than the capacity of a convoy, increases the transit time: goods spend a long time at a station, seeing multiple convoys pass before it's picked up. In response, the just-in-time algorithm increases the amount in transit, making the pile bigger and increasing the transit time even more.

At some point, an alternative route, with a longer base travel time, gets a shorter transit time, as there are no big piles. Now goods get a new route, taking the detour. Obviously, the capacity of the detour is even less, so it won't take long before a new pile of goods appears. And these goods taking a detour may disrupt the flow of goods that were intended to use the ways of this detour, forcing them to their own detour, which can prevent the system from recovering on its own.

Some tricks to prevent this: avoid having alternative routes in you transport network. If you have alternative routes, make sure that the preferred route operates well below capacity. Unfortunately, this increases cost. If a source only produces one product for one destination, make sure that the first link in the chain has the lowest capacity. Now the pile (if any) will appear at the pickup station, where the pile is limited by the storage capacity of the station.