Print

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

[brucemo]

Here are the findings I said I'd post when I necro'd up this thread.

The situation in my fort was that I was going to haul magma up 145 z-levels in order to fill 9 pits to 4/7.

How I created this route is that I went exploratory mining via a 4x4 single-wide square downward ramp spiral. If I hit a cavern I sealed with a construction then re-routed around the cavern, always intending to make a route that is of optimal length, which is rarely difficult.

Eventually I hit magma sea this way and can plan my magma lift track, which I describe at length in this Reddit thread (http://www.reddit.com/r/dwarffortress/comments/1izu55/a_simple_way_to_collect_and_move_small_quantities/), for those interested.

My initial concern in previous "cursed" forts was that the ramp bug had caused a problem at a place where the route diverged, with one path going off to dead end, and another path continuing down.

This does not appear to be the problem, since in my current fort, I ended up with a pile of magma from a cart wipeout (the implication is that the cart was going up, if that's of value) in a place where there was no junction.

So this is happening in a vanilla loose spiral.

I have a save from before when I started to lift magma, and I ran this approximately three times and had cart wipeouts every time, pretty early on. In none of those attempts did I get more than 3 pits filled. I then segregated all pets into a pasture, and forbade every object (all rocks) below the magma forge level.

So pets should have not been able to go down there, I do not believe there were any kids yet, and there should have been no reason for a non- cart-pusher to go down there unless he wanted a drink of magma or something.

I ended up running 20 loads of magma up without a disaster.

I haven't proven that collisions with dwarfs or pets cause this problem, but I believe that the evidence points to this.

[AraJudge]

Is it bad of me to want to open this up again? Has anything been found out as to why this happens. I have only had it happen once so far but this is also the first fortress I have ever used a minecart in (don't know how i ever managed without one before... oh ya I didn't.. i died).

I see that mid transit my cart became  unaccessible for some reason... but why did it become unaccessible? Very strange... very strange indeed.

Anyone got any new thoughts on the matter?

[Aslandus]

I had this problem with the one minecart track I've made, my dwarves were using wooden carts to haul stone up about five z levels and one time I saw about three dwarves had gotten injured by a wild minecart. I assumed the dwarf guiding it had gotten distracted while guiding the cart and dropped it down the ramp, where a few others got hit by it. That minecart had more casualties than the minotaur that attacked six months earlier...

Next time I make a track I'll have to make sure it's not the shortest route to the next floor

[AraJudge]

Ya. I think I have managed to avoid a lot of these occurrences by making my track go from strip layer to topside in a ramp of its own. It doesn't go through my fort at all so dwarfs don't path it as the fastest way to get anywhere.

From this thread I would say that the cause is being distracted by.. say having a child, or something like that. Causing them to forget what they where doing and move to something else. I guess this could be tested by having a cart pushed up a track and then making them path to a burrow and see what happens to the cart.

If I find the time I will test it and then come back with results. Not really in a place in my current fort to test such a thing just yet.

[Loci]

I see that mid transit my cart became  unaccessible for some reason... but why did it become unaccessible? Very strange... very strange indeed.

"Unaccessible" probably means your cart was moving too fast for a dwarf to get a hold of it... which is a sign that the problem had already occurred, not the cause of the problem.

Releasing guided minecarts sounds like another "creature swapping" bug. (Creature swapping occurs when one creature moves into another creature's tile and the other creature is automatically relocated to the first creature's original tile.) Swapping momentarily distracts the swapped creature (red question mark) providing a cart on a ramp time to accelerate out of control.

[Hetairos]

It seems to occur most frequently (at least in my case) when there are other dwarves or creatures on the tracks. You might be on to something with that creature swapping thing, if it really happens; this is admittedly the first time I hear about it.

[Larix]

As circumstancial evidence i could offer that i'm very careful to keep minecart tracks separate from normal paths and have never had trouble with guided carts spontaneously getting loose.

To alleviate the problem, you can always use non-functional ramps - ramps without the proper connections, so they don't accelerate a cart. The code checking whether a track is connected is fairly lenient and will usually be o.k. with a ramp like this:

Code: [Select]

###     ###
#▲#     #╩#
#.#     #.#

actual track goes N-S, a NEW track ramp counts as connected, a S connection isn't required, and since the ramp has no connection to floor, it doesn't accelerate. I've actually built such paths as guided cart tracks and the dwarfs guided the carts along them just fine.

[omega_dwarf]

The creature swapping idea sounds like it could be the case.

I had a fort with this problem a while back (I was making a castle, and using multiple minecart tracks to move stone up from the quarry and dump it by the mason's workshop.) I think I decided it was related to dwarves dodging out of the minecart's path. I had some hatches leading to the caverns right by the end of my tracks, and I think when I moved them and floored over the holes, I got fewer if any injuries.

[Max™]

Is it weird that this gif made me think of this thread and my early accidents when I learned that ride is very rarely safer than guide OR push.

[Kamamura]

I just imagined homing mincarts loaded with explosives and serrated candy discs as anti-dragon flak battery... oh joy.