'Go to nearest depot'

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trainrover
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'Go to nearest depot'

Post by trainrover »

I used to specify depots when ordering trains to be serviced when necessary for them to do so, and I experienced no hassle. Now building multiple depots at key points around the network I'm currently building all for the intention of smoother flow and the fewest jams possible, my trains now take to calling at depots to be serviced WHENEVER they need to. Is this servicing operation quite normal with the 'Go to nearest depot' order, or might something be genuinely amiss with this particular instruction, because my timetables are severely being compromised?
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Re: 'Go to nearest depot'

Post by Alberth »

Did you add slack to account for detours taken by the vehicles?

To see why you need this, imagine that you are a bus driver, driving circles A -> B -> C -> A ...
You always drive at max speed. I am in the bus, and have measured that each leg takes 10 minutes exactly.
So far so good. You drive around, and arrive everywhere exactly on time.

Now suppose we add a depot between A and B. It takes 1 minute exactly to service the bus. To keep things simple, assume servicing is done every time we drive A -> B (if not, it takes longer to run into trouble, but the end result is the same).
In this situation, A -> B takes 11 minutes instead of 10. However, I didn't measure it again, and still use 10 minutes time for each leg.

In my book, you arrive 1 minute too late at B. Since you are already driving at max speed, you cannot increase speed to catch up, and thus you will also arrive 1 minute late at B, and similarly at C and at A.
The second round of A-> B, you're going to be 2 minutes late at B. With no way to catch up, you stay 2 minutes late.
etc etc

Pretty soon my times are completely useless.


What happens here is that any second you loose is not recoverable. The time table doesn't account for it.
The solution is pretty simple, add some duration to each leg (eg 10.5 minutes for each leg). If we are ahead of time, we wait until the right moment to leave has arrived. If we are late, we leave as soon as possible.
Since you driving at max speed makes us arrive early, eventually we will catch up again (unless we stop at another depot of course).



I don't know if depot servicing on route is common, probably not. Most people prefer to play without breakdown. I do play with breakdown and servicing enabled, as I like the additional challenge that it brings. As you found out, precise timing isn't possible any more (with just servicing already, with enabled breakdowns it gets worse). You have to build additional tracks and platforms to handle lack of predictable arrival times.

Decide whether you like a challenge, and play accordingly :)
Being a retired OpenTTD developer does not mean I know what I am doing.
trainrover
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Re: 'Go to nearest depot'

Post by trainrover »

Oh yes, I've plenty of slack for each of my depots, i.e., Ctrl+Autofill will most often replace my 6 days' worth of timetabling with mere single days (because the trains needed no servicing when being instructed to retime their altered routes).

Maybe I hadn't elaborated enough there. Let's say a fleet of my trains calls at stations A, B, C, D, E, F, G, and lastly H; on the return leg, the order of called at stations is simply reversed. Yet from A to B and from H to G are single Go-to-nearest-depot orders (X), i.e., A X B C D E F G H, then H X G F E D C B A. My (our?) problem is that the trains will immediately respond to their servicing needs wherever they be along their routes, which invalidates any utility/usefulness to there existing a Go-to-nearest-depot order. You see, ordering which depot a train must call at bears no problem, but letting a train circumstantially select which 1 of the huddled 2, 3 or even 4 nearby depots to call at has so far been both completely useless and MEDDLESOME (grrrrr), because my trains will go, e.g., ..D X E.., ..C X B.., etc., etc., which more often involves lengthy and awkward detours.
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Re: 'Go to nearest depot'

Post by leifbk »

I don't have much experience with trains, but I always insert unconditional "go to depot" orders in every vehicle's orders lists for each round-trip, unless it's a very short route; then I make the depot order conditional. Also, it won't do to just order them to go to the nearest depot; I set an explicit "go to Flardinghattan Depot" which usually is their place of origin. This way, the depot stop will be included in the timetable as part of the route. If the route is longer than the regular maintenance interval, I'll insert a second depot order, usually at the other end of the route. (With vehicles moving at 20 km/h, you may even need to place a depot in between the end points to give your horses a well-deserved rest.)

I've used this method successfully for 4-horse mail wagons running on shared orders and shared timetables from 1700, and they'll run flawlessly for more than 200 years, until they are replaced by automobiles. But like Alberth says, you need to give your vehicles some slack to enable them to catch up with the timetable. I'll usually give them 4 days on each station rather than the default 1 day; they'll shorten that interval (and still take all available cargo) if they're late.
trainrover
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Re: 'Go to nearest depot'

Post by trainrover »

Alright, then I'll revert to specifying particular depots to be called at. Thank you all.

By the way, members' fixations on horses & wagons fascinates me, and so I'm now resolving to try them out myself in my next map.
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Re: 'Go to nearest depot'

Post by Baldy's Boss »

There's always the simplest method of forcing service...remove the section of track that bypasses a depot entrance so that every train that reaches it must enter.
trainrover
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Re: 'Go to nearest depot'

Post by trainrover »

Hmmmm, hang on .. I'm glad to be rereading your replies during another day. Now some way through the midst of reapplying my depot orders, was/is(?) my problem in fact the sub-category (i.e., 'Always go', 'Service if needed', & 'Stop') of depot ordering, because I'm still making them conditional, i.e., service if needed? You see, when I'd used to specify the depots, callings were mandatory, plus the servicing interval wasn't 450 days either like I've been setting it this map around.
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Re: 'Go to nearest depot'

Post by Eddi »

trainrover wrote:My (our?) problem is that the trains will immediately respond to their servicing needs wherever they be along their routes, which invalidates any utility/usefulness to there existing a Go-to-nearest-depot order.
this behaviour is wrong. you should provide a savegame that shows this and open a bug report.
You might not exactly be interested in Ferion, but if you are, have fun :)
trainrover
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Re: 'Go to nearest depot'

Post by trainrover »

I'd probably be wasting the devs' times were I to do so, for I have a hunch that I've compromised the game state of the downloaded scenario (RIGHT) from the outset from having lumped in new goodies (accessories .. newGRFs). I say this now because of subsequently trying to add in JUST 1 more goody. No quirk occurred just last year from drawing upon some speedy inter-city coaches, but this time (i.e., "subsequently") around, all those coaches default to tourists, and upon immediately refitting the models to passengers, their capacities all jump to around 350 passengers. There, that's a reason why not.
trainrover
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Re: 'Go to nearest depot'

Post by trainrover »

T@-d@hhh It's just dawned on me how to properly utilise "Go to nearest dépôt"...with highly-served facilities, having a pair of depots nested nearby to one another is necessary - headways tighter than roughly 11 minutes a piece, say - as embarking on just a single depot obliges following trains to needlessly await their own entries while their predecessors exit the measly single shed. The trick is to NOT protect the depot approaches with any signal there along, and - T@-d@hhh - it works, i.e., alternate depot is successfully chosen when chief choice happens to be occupied itself, although I haven't bothered trying such a set-up with any signal along either approach. I'll post a video once said high throughput return to my game 🍸

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