Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[Large Wereroach]

Cheers, fellow Urists.
I've done some google and read the wiki, but could not find a satisfying answer so far, so for Armoks sake, I'll just ask here.
* will rocks or other stuff lying on a track derail my minecarts?
* what is the exact de-railing speed and do ramps (downward in my case) trigger a derail?
My specific situation is that I've built a track alomst 200 z-Levels deep and at some point or another the cart will drop its cargo. I've done some amateurish !Science! by building track stops and setting them to different frictions, but stuff will be dropped anyway, altohugh at different places. I've come to fine-grain a setting that finally had the cart go the whole way with neither dropping anything nor stopping halfway. Worked alright for at least 20 tours or so, but now it starts dropping again.
My level ramps are all in a straight line , so EW-Track - EW-Ramp - EW-Track everywhere. The location where the cargo drops is situated some way off the next stockpile and clearing the track does not have a high priority, it seems. But anyway, someone here surely knows whether a clay boulder on the track would have a cart drop the cargo?

[Fleeting Frames]

Ctrl+F on minecart wiki

1. Ctrl+F "colli" - 2nd is Danger section - "If an unlucky dwarf or creature fails to dodge a minecart, they can be injured." & "Danger does not always involve living victims: careless route designation can also result in minecarts careening off tracks or colliding with each other. If this occurs, the items may be scattered; this can cause even more hauling jobs than the minecart aimed to eliminate. "

I suppose it could use a clarification that non-minecart items laying on the floor do not affect the minecart - but you presumably observed that yourself.

2. Ctrl+F "speed" - first on page is link to controlling speed - "Minecarts can reach extremely high speeds, especially when descending multiple Z-levels. A minecart will derail at a track corner if its speed exceeds 0.5 t/st (tiles per step), unless the route in the direction of travel is blocked: "

or Ctrl+F "derailing" - fourth is " "Derailing" can happen when a cart moves at speeds in excess of 50000 - carts will ignore track corners unless forced to obey them by walls or other obstacles blocking the straight path. "


Your case, however, is neither of those - no, it's what's described just below the last - "The "shotgun" effect takes place when a collision changes a cart's movement speed by more than 55000".

What's happening to cause the collision is cart jumps - " Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the Checkpoint Effect is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill."


Every tile can be a ramp instead - you use twice as many tiles as you need to+whatever you use for slowing down at the end. Bonus note: I generally recommend using bidirectional rampways such as in the moonhome and deathgame maps in my signature, but it's too much of a hassle to readapt; I'd instead ensure minecart always enters the descending rampway at same speed and build track stops as necessary to stop the jumping into a wall. (you can later link the stops to levers to ensure the cart does jump at desired z-level, and, say, through a fortification).

[Large Wereroach]

Hi there, and thanks a lot for answering!

I suppose it could use a clarification that non-minecart items laying on the floor do not affect the minecart - but you presumably observed that yourself.

No, actually I didn't . One of my first cartruns hit (of course...) an unsuspecting dorf and inspecting the cart on the next runs always reminded me of that collision ("spatter of Urist McInnocents blood"), so I expected general interaction with things the cart runs over.
When the cargo is dropped, it takes forever until the cart is hauled back to the starting point ("micromanaging" around it to carve new stops with stockpiles on the drop levels also takes forever...), so my test-runs are few and far between and lack reproducability. -> being certain that the debris on the tracks is not an issue makes it at least easier to tweak the braking stops...
Also the cart will happily drive on down to z -195 after dropping stuff on level -70 or -130 or -189, so I was assuming it would not exactly "derail" but merely lose its load (like: cart going down the ramp, but cargo too inertial to make the drop along with it).

Your case, however, is neither of those - no [...] What's happening [...] is Carts that approach a downward slope at a high enough velocity will also make a jump, (or rather, ignore the ramp and fly forwards) but will not do so if the Checkpoint Effect is exploited through an impulse ramp before the actual downhill as the impulse ramp "tricks" the cart into thinking it has already started going downhill."

OK I've come across the term "impulse ramp" several times, maybe I actually should read up on it. The idea of re-carving 200 levels worth of 6x2 tiles isn't very appealing though, so for now I'll try some better placed stops for braking.
Thanks again!
LW

(post scriptum: it's only 153 levels... pita nonetheless)

[PatrikLundell]

It cannot be stressed enough how important it is to ensure critters don't walk on the tracks, as the hauling jobs to remove the critter bits + equipment tends to result in more bits as the haulers are smashed. The entrances and exits have to be blocked to creatures or visitors trying to leave fortresses under lock down, cats, diplomats, etc. may well walk on the tracks.
I've used pressure plates hooked up to doors in the past, but have been told statues work well as being impassable to critters but passable to mine carts, although I so far haven't made a track to test it out.

For downwards travel I use a drop chute, i.e. a track that ends at a vertical shaft landing at a ramp with carved tracks at the bottom, and I use impulse ramps to propel the cart back up along a track circling the drop shaft (requires some tuning to ensure the dropping cart hits the wall at non load dropping speed to fall straight down rather than landing on a track and return up).

[Fleeting Frames]

Yeah, the aftermath does look kinda like cargo expels itself from descending minecart at speed. More that minecart that is on an accelerating ramp is always going to be accelerated, even if they didn't roll onto it and were, instead, just dropped on it or stored on a stockpile on the ramp.

For understanding minecart physics, I recommend Larix's 10 lessons. Shorter than the wiki, though it is only really about track/ramp movement.

6x2...Oh, six parallel tracks? Okay, that might be a pita indeed to build track stops for that. In that case, I'd recommend going through it with a macro to designate NS tracks over each set of six ramps, from z-level before the earliest point where it expels cargo, thus rendering them non-accelerating.

[Large Wereroach]

Hi there, no it's not 6 tracks, only 6 tiles per layer, like ramp_ew, track_ew, track_en, track_sw, track_ew, ramp_ew (you get the idea, the names may be wrong ).
I managed to tweak the brakes underway, so now the whole route goes smoothly and no cargo is lost. Thanks for hinting me in the right direction. On re-reading the wiki I found that I completely underestimated the difference in braking-power from "medium" (500) to "high" (10000). A medium trackstop is of course next to useless on a downward spiral like that with hardly any horizontal movement but some 20-30 layers downward chimneys, so not very surprising that the cargo got dropped at the same spot "although I've just built a medium brake right in front of it".
Thanks again, very nice folks here

[Schmaven]

I just tested statues on the tracks and they do allow carts to pass but not dwarves.  I imagine them as having gaps perfectly shaped for minecarts to fit through but not dwarves.

As far as re-designating 200 z-levels is concerned, I highly recommend looking into macros.

[Large Wereroach]

I did it with a Macro... got one tile wrong, namely digging away the ramp on one side... I only found it out when my digging dwarf was hanging around somewhere in the deep and wouldn't do much. When it became clear that's because all the ramps are removed, I started another Macro-Session: construct ramp... ctl-p, ctl-p, ctl-p, cavern layer, ctrl-,ctrl-p,ctrl-p, layer where I did one thing manually slightly different, ctrl-p, ctrl-p. I mean, it's not even 200, only 153 levels, but that was enough for this game. I wanted to do it all with rollers upwards at first. No way, this will maybe be done in the next game  . For now I'm happy with clay going downward alright and a poor dwarf guiding up the brick-loaded cart.

[Schmaven]

Control + u lets you specify how many times to repeat the macro, then just cntrl + p once plays it that many times.  No need for spamming it manually

[Large Wereroach]

Nice  Man, there sure are a lot of tweaks and details to this game