Bay 12 Games Forum

There are couple of possible overseer-triggers, simplest that I know being cat under a hatch with pressure plate immediatelly out of it, but none are quite instant (without involving dfhack, anyhow).

Yeah, DFHack really does uncork the bottle.  I guess one could just use teleport to move any critter onto or off a pressure plate.

In any case, I prefer ones that rely on the exploit where a raised bridge marked momentarily for deconstruction becomes statue-like for the purpose of letting objects pass.

I did not know that effect.  Presumably the actual in-universe switching gets done by redirecting a minecart that will be along promptly because it's running in a repeating circuit?

Also, it might be that you could replace 1x1 retracting+raising bridge with 2x1 raising bridge, if the water being atomsmashed on retracting bridge tile doesn't harm the operation (it functions as drain, so...).

Yes, that does work and would save two blocks and four mechanisms for the pressure plate linkages (plus more mechanisms for arming lever linkages).  I couldn't remember whether a raising drawbridge destroyed water above the whole bridge or just its hinged edge, the wiki didn't make it clear, and I just didn't feel like testing it when I knew the two-bridge implementation would give the measured aliquot I needed.

This sort of thing walks along the boundary between honest play and exploitive cheating.  One's personal palate determines how much exploit can be swallowed.

[HomerSimpson]

DOH!

[/HomerSimpson]

I knew that about track stops.  I've used that track stop behavior, mostly to fixup after bugged haul route loading^footnote.  Just never occurred to me to use it to dump water onto a switch.  Four years of college...wasted.

A nice benefit of this scheme is that it's simple to choose from ON vs OFF or momentary vs persistent behavior:
- Prompt ON or prompt OFF behavior determined by whether pre-dump level is within or outside switch level range
- Prompt momentary ON if there is adjacent space to drain dumped water away, prompt persistent ON if not
- Prompt persistent OFF if no adjacent drain space
- Prompt momentary OFF might be trickier; need to lower level back into ON range.  Linked drawbridge blocking drain space (possibly diagonal) might do it.

^footnote For some reason a route and stop intended only to dump minecarts brought up full of magma for use can get tangled up with instructions for another route and stop to load the emptied minecarts for travel back down to the filling station.  I think there may be an indexing problem when a erroneous stop (on an unrelated route) got deleted and fixed; I didn't report or search for the bug because I haven't tried hard enough to isolate the root cause nor demonstrate repeatably.  The Q&D workaround (and likely robust avoidance design) was to redirect dumpage to a new, distinct QSP stockpile.  Made my dozen-magma-loads-per-trip operation slightly more tedious, but not enough to rework the layout.

IIRC, there was something involving cancelling a partially-built construction. Can't remember the details.

The wiki says cancelling a partially-built construction can drop the building materials into open space beneath.
https://dwarffortresswiki.org/index.php/DF2014:Trap_design#Canceled_construction_deadfall

While that might be fun for observers below, I don't see how it can (directly) send a signal to activate a mechanism linkage.  That is, I don't think there's a way to park anything on the unfinished construction that can trigger a pressure plate below when the construction is cancelled.  Pressure plates don't respond to ordinary items like construction materials.

I suppose one could confine a critter atop a pressure plate in the drop zone.  The living creature holds the pressure plate ON until falling material turns him into a corpse and lets the plate toggle OFF.  While that might work (with some careful planning to avoid spurious triggers during setup and reset), to my taste killing a critter per shot seems wasteful and the initiation seems a bit exploity (emphasis my taste, which is more willing to accept the overseer's hand than an implementation convenience detail of letting works in progress hang mid-air)

Aquifers are easy once you get below them. Find the first cavern, build a drain, and dig up into the aquifer however you want.

This, IMHO, is the key to generalized aquifer penetration.

Everybody wants to end up with nice wide passages through the aquifer layers to avoid traffic bottlenecks.  I like to separate that problem from the more pressing chore of just getting any passage at all through the aquifer.  Once a drain (to cavern or through map edge) can be established, it's simple to open arbitrarily large spaces in aquifer layers.  Then I can put vertical access wherever I want, as wide as I want, without any aquifer complications.

All aquifer layers (true aquifer, not the damp stone below) but the bottom can be drained handily into the aquifer layer below by digging down (or up+down) stairs into the upper layer over up (or up+down) stairs into the lower layer.  When there's another aquifer layer below, you need only one pumping operation from the upper layer to enable access to dig the first down-over-up stairs combination.  The pump can then be dismantled while the rest of the upper layer is dug out with down-over-up stairs, as widely as you require.  Small areas of the upper layer can be simply mined out to leave flat floors (leaving pristine aquifer tiles beneath), to simplify pump placement to start working the next layer down... and securing an initial stairwell through the bottom aquifer layer.

Digging the down stair from the layer above reveals the composition of the tile below, and probably indirectly whether that layer is aquifer or merely damp from aquifer proximity.  If it's a permeable soil or rock tile that can support an aquifer, the next layer is also aquifer; if it's clay or some non-permeable stone, it's (probably) not (I had one multi-biome embark with puddingstone that carried the aquifer way, way down, which I abandoned without complete understanding).

So...you need only one pump (moved layer to layer) and zero wall/floor/stair construction+deconstructions to get down to the bottom aquifer layer, and recognize it as such by the first up+down stair dug in it.  That bottom aquifer layer can swallow all the water leaking from the boundary of all shallower layers, but until you establish a drain there's no place for it to go.  Whatever you dig out in the bottom aquifer layer will fill with 7/7 water.  Non-aquifer rock (or clay) below won't absorb water, so the up-over-down stairs combo won't dry out the bottom aquifer layer.

Fortunately, a single pump placement can drain two tiles enough to let you build isolating walls if the directly or diagonally adjacent tiles aren't full of water.  This lets you punch a single (1x1) up+down stair through the last layer, with a little care not to dig too close to that point with the upstairs draining the layer above.

To clear an arbitrarily large area (at least 5x5 [7x7 counting boundary walls]) area of an aquifer layer that is NOT the bottom aquifer layer, start with an up+down stair dug from the (now) dry layer above.  This will reveal the composition of the layer below, and whether it's another aquifer layer (if not, skip this part and jump to ).  Dig a ramp in the third tile away for intake of a pump to discharge into your stairwell.  While pumping, dig down-over-up stair combinations in the upper and lower aquifer layers next to the ramp:

X up+down stair
^ up ramp
d down or up+down stair (up or up+down stair in layer below)
. original tile, unmined

Aquifer layer *overlying*another*aquifer*layer*

.......
.......
.......
...X...
.......
.......
..d^d..


Once you have a couple down-over-up stairs dug, you can stop and dismantle the pump and extend the down-over-up stairs as far as you like; include stairs to the layer above for access, and then dig out the ramp with down-over-up stairs to clear out the aquifer tile below.  Don't designate too large an area at at a time; if too many down stairs get dug too far away from up stairs below, water flowing to distant up stairs will keep your miners from digging closer up stairs drains.  At best, job cancellations will greatly impede progress and designation calculations can leave unmined aquifer tiles below to muck up final drainage; you might even put yourself in an unrecoverable situation.  Before moving on to the next layer, check to be sure every intended aquifer tile actually got mined away; a single straggler left by a job cancellation is easy to fix now, but can bite you hard later.

With water falling from upper aquifer layers into lower aquifer layers, there's no hurry to construct sealing walls.  Yeah, the falling water might impose a slight FPS burden, but in early days with low population and little junk there's FPS to spare.  I defer sealing until after everything is drained, busy work for dorfs with nothing better to do.

If the next aquifer layer might be the bottom of the aquifer, don't dig anything too close to where you intend to put the final piercing up+down stair.  That tile and the tiles where you'll put its sealing walls needs unmined neighbors for protection from all the water coming from the rest of your diggings; mine the penultimate layer in this pattern:

X aquifer-penetrating up+down stair location
^ up ramp
d down or up+down stair (up or up+down stair in layer below)
_ any mined, walkable (floor or stair) *NOT* mined below

Aquifer layer *overlying*bottom*aquifer*layer*

ddddddd
dd___dd
d_____d
d__X__d
d_____d
dd___dd
ddddddd


Dig the outer down-over-up drains before the undrained interior area, to minimize cancellation delays from water produced by the last interior aquifer tiles.

Channel out the tile and set the pump to drain the final penetrating stair location.  While pumping:

THREE times: Dig ONE up ramp orthogonally adjacent to stair location, and construct a sealing wall there

Dig up ramp at the fourth orthogonally adjacent location.  Construct the central up+down stair first, then the fourth sealing wall.

There's no need to construct walls in the diagonally adjacent tiles (aquifers bleed only orthogonally), but DO NOT MINE THOSE TILES until the penetrating stairwell connects to the drain system.  If you want to put walls there (belt and suspenders?), you'll need to leave more tiles unmined (or allow for more pump relocations) to avoid bulk drainage spoiling the construction.

Construct down (or up+down) stairs in the layer above, and dismantle the pump.  You can now dig up+down stairs to get below the aquifer (and the damp layer just under it).

Dig stairs straight down to the depth of your drain channel layer, at least three levels (preferably more) below the bottom aquifer layer.  At least at drain channel depth and at the second layer below the aquifer, mine laterally to the boundary of the aquifer area you want drained.  Dig up+down stair drains around the periphery, from the second layer below the aquifer to your drain channel level.  Dig your drain channel to the caverns (or map edge; DON'T FORGET TO SMOOTH AND FORTIFY MAP EDGE TILES TO ENABLE DRAINAGE OFF MAP!).

To minimize job cancellations and FPS drag, up in the aquifer I find it best to dig out all but the outside two tiles of the area to be sealed (one buffer plus where the sealing wall will be constructed) and dig the peripheral drain under the sealing wall position.

First dig out the complete drain system below the damp sub-aquifer layer.  Then dig up-stairs from the drain upwards, all around the periphery, one layer at a time, all the way to the top aquifer layer.  Working up one layer at a time avoids job cancellations when an upper tile gets dug first and its water impedes access to dig the tile adjacent or below.

Once the peripheral drain reaches the top of the aquifer, dig out the one-tile buffer zone in each aquifer layer, again working layerwise but top-down through the bottom aquifer layer.  Simple mining would probably work, with a bit more cancellations, but I stick with the proven down-over-up stairs method.

Work strictly top-down when walling off the periphery; a wall on a lower level can obstruct the drain enough to make sealing the level above, or even removing the errant wall construction, impossible (I think).  Before building any walls on a level, double check to be very certain that every interior aquifer tile has been mined away; as walls increasingly inhibit drainage flow, even a single aquifer tile can flood a level.  Don't forget to dig out the "buffer" tiles around the initial penetration stairwell when the bottom aquifer layer has drained enough; some water will flow into the initial stairwell, but you did connect its bottom to your drain, right?

Once everything's drained away, your miners can remove up stairs from the bottom aquifer layer to leave you flat floors.  Alas, upper layers will be riddled with down stairs until you construct floors.  I haven't yet had the need, but you can probably dig out small areas to leave floors suitable for clay or sand collection (not possible from constructed floors nor down stairs...not sure about up+down stairs).

This procedure takes about a game year to clear a 30x60 (or so) region through a two or three layer aquifer (longer to finish sealing walls, but there's no real rush if the drain's out of the way); first breakthrough takes only a few weeks.  A nice benefit is safe access to the large magnetite cluster and platinum that always seems to lie in the damp stone right at my fort.  Digging the drains gives a bit of stone for early buildings and mechanisms.  I can put stairwells wherever I want through the drained area without hassle.  All that soil mining trains legendary miners, ready to be deadly killers in my first elite infantry squad.

Maybe I'm doing it wrong, but a single double-slit operation takes several months per penetration and still focuses traffic.

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b) it's the track stop, not the hauling route, that dumps anything in the minecart in the chosen direction, and (virtually?) immediately.  Besides, we don't want stuff to linger indefinitely in limbo waiting until the minecart fills up.

Yup, it's a good idea to set up more frequent dumping conditions.

No.  For a minecart quantum stockpile you don't need to set up *any* dumping conditions at all, other than building the track stop to automatically dump toward your quantum pile.  Hauling route dumping and departure conditions shouldn't come into play at all.

The track stop automagically dumps the minecart before the route stop can even notice whether it's full.  The hauling route should consist of a single stop (conveniently located on the track stop, so the dwarves will put the assigned minecart there); with nowhere to go, departure conditions don't matter.  Or shouldn't, anyway; for my QSPs I always delete all the offered conditions from the route stop, using it only to designate what to pick up from which stockpile (to be promptly dumped by the track stop onto the quantum pile).

Immortal-D, you could probably also benefit by learning to use minecarts; you can use them to quantum stockpile stone (or other objects), and you get the benefit that dwarves can use wheelbarrows to get the stone to the stockpile that feeds the minecart, so things will go much more quickly (and with no need to fiddle with dumping).

The long and short of it: create a stone stockpile that allows wheelbarrow use. Next to it, have your dorfs carve a single tile of track (to do this, first smooth the room and then designate two tiles of track to be carved; you may then un-designate one of the two). Finally b-(C)onstruct a track stop on the tile of track, set to dump in any direction except back into the stockpile you've designated.

Now that that's done, create a single-tile stone stockpile wherever you set the stop to dump, and create a (H)auling route that takes from your feeder stockpile and dumps when full, and that has a minecart.

It sounds like a lot, but once you learn the trick it's very handy. You can also use this as the basis for learning about minecarts in general, which are a cool feature.

Sounds like more than it needs to be.  In particular, I struck out some superfluous stuff above:

a) no need to carve or build the track segment; just build the track stop, set to dump onto the quantum stockpile tile (*not* back onto the "feeder" stockpile).

b) it's the track stop, not the hauling route, that dumps anything in the minecart in the chosen direction, and (virtually?) immediately.  Besides, we don't want stuff to linger indefinitely in limbo waiting until the minecart fills up.

c) the track stop does need to be orthogonally adjacent to the quantum stockpile tile so the minecart can dump directly onto it.  There's no fundamental reason either must be near the "feeder" stockpile, but the further it is the more time dwarves will spend carrying stuff from there to the minecart; that includes walking across the feeder stockpile that we're automatically draining into the quantum pile, so for good speed don't make that more than a few tiles bigger than to accomodate its wheelbarrows.

Track would matter to *guide* the minecart to the next hauling route stop (without track a guided minecart would be *carried* to the next route stop; without any track, a minecart could be *pushed* or *ridden* away... or just sit there).  Hauling route minecart fullness criteria are about when the minecart should be moved on to the next route stop.

A quantum stockpile needs neither... you want the minecart to sit right there and dump whatever it's got as soon as it gets it.  The track stop implements the dumping behavior; the hauling route stop defines what gets loaded into the minecart, where it comes from, and that there's no reason for the minecart to leave.

Minecarts and their interface are a bit tricky to learn (the distinction between *track* stops and *route* stops, and how you often need one but not the other, caused me some confusion).  Quantum stockpiles are one of the best applications, and a good way to begin.

Pressure plates stay triggered for 100 ticks after they're released, but the bridge won't raise again if it's pressed right after that.
Doors will kill vermin when they close, leaving remains, so they will get stuck.

Huh.  Guess I FUBAR'd my prior test of bridge and floodgate operation by minecart pushed across pressure switch.  Tore it down and built it all again; now the bridges and floodgate wink out after the minecart passes.  Haven't tested whether they stay open long enough to operate my latches, but should do.

Thanks for setting me straight.