JGR wrote: ↑23 Apr 2021 19:54
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Hafting wrote: ↑23 Apr 2021 15:36
Roll-through train depots have a small problem: Every time a train is about to roll into one, I get a "lost train" notification. The train get through to the station - no problem with routing. But I get spammed with these messages. I can only guess the pathfinder consider the train "lost" because it doesn't always consider the new roll-through option?
I have two depots back to back, in front of a station. And another double depot next to this, for higher throughput. The trains have no depot order, only an order to get to the station on the other side. This so it may use either the left or the right double-depot, depending on availability. I use realistic braking, if that makes a difference.
An idea for further enhancement: Merge adjacent depots into a single larger depot. One may then give a train a depot order, and it will use whatever entrance it finds unobstructed. Just like stations with multiple platforms.
In general, it's best to always have at least one service at depot order in the order list for trains, road vehicles and ships.
Unfortunately, trains sometimes need to
not have a depot order: The amount of cargo moved, may need a higher frequency of trains than a single depot can handle. (FIRS, when you boost an already good mine with engineering supplies.) A depot order will have all trains queue up for that depot, limiting freight capacity to how many trains a single depot can handle.
One alternative then, is to have two depots, placed so the train must go through one or the other in order to reach the next station. No depot order, but the train will be serviced on every roundtrip. (There being no direct route to that station, so the train goes through the first uncongested depot and gets serviced) If the roundtrip is very long, have several such double depots spread out to prevent trains from seeking out a random depot for emergency service.
A much more cumbersome alternative is to have two sets of trains (A and B), which are serviced in different depots, using depot orders As you get more and more goods, you have to be careful to buy more trains in pairs - this is the cumbersome part. If trains from set A and B don't alternate perfectly along the line, then depot queues and delays still happens. No such problems with double depots and no depot order.
At the moment the pathfinder does not look through drive-through depots for so that trains don't use them as a shortcut (and for implementation simplicity).
Simplicity, I understand. You surely have more pressing issues than my wishes.
But the pathfinder would not use the double depot as a shortcut unnecessarily. It already avoids unnecessary trips through single depots, preferring direct railway. Surely, the pathfinder knows the depot represent a delay. The only case I see trains going unnecessarily through depots, is when the direct route is blocked by other trains. That is acceptable and wanted behavior.
Getting the "lost train" message for every train, means drive-through depots aren't useful unless there is a depot order. With a depot order, no erroneous lost train message.
The drive-through depot theoretically allows more throughput than the ordinary depot - as incoming trains don't need to wait for leaving trains. They only need to wait for the previous incoming train, which goes at a "depot speed" slower than "normal speed". For that reason, having two sets of drive-through depots may still be necessary for high throughput.
In practice, a single drive-through depot does not work well, at least not with realistic braking: One train rolls into the depot. As soon as it is in, the next train reserves a way into the depot and start rolling. This is as it should be - but unfortunately, the first train is prevented from transferring to the 'leaving depot' when the second train has reserved a way into the 'entering depot'. The result is that
all trains on this congested line gather in 'entering depot'. Eventually, no train is trying to get in. Only then are trains transferred to the 'leaving depot' and is able to go to the next station.
This problem does not happen when I have two sets of drive-through depots. A train will roll into the left drive-through. Before all of it is inside, the next train arrives at the split, and finds an unobstructed way into the right drive-through. When the first train is fully inside the left drive-through, the second train is still blocking the split, so the third train cannot immediately reserve a path into the left drive-through. So train1 gets the time it needs to transfer to the 'leaving depot'. This works very well, except for the continuous messages about 'lost trains'.
Interesting, and good to know.
Plus, it can be later suggested to be pushed upstream, if not buggy.
