Bay 12 Games Forum

Steel actually isn't available, my map has no flux.  Besides, it's sort of pointless now that I have adamantine (and lots of it) for weaponry, and in everything that adamantine isn't better for than steel, iron serves equally.

I've had to let my construction slide a bit, since I've been sort of slammed at work.  I've got five more reservoirs coming up, should be done after my next normal build session.  By way of making up for the silence, I'm going to post some pics that accumulated.

First off, here's my fortress plan.  The grid for the network shown here would extend all of the way across the map in x-tiles, but there's still some space up top it wouldn't cover. 
http://img35.imageshack.us/img35/4589/planm.png
It's jiggered so that the longest route to any extreme from the source is 12 pipes or so, which is pretty doable based on what I've seen from the close-in fill action. 

Secondly, and worth a mention for the fun factor, is that I had a goblin snatcher try to snatchinate one of my precious dwarf kids.  Instead of dispatching my embarrassingly effective squad of swordsdwarves, I elected to perform a small science experiment.  I imagine it played out something like this:
http://img208.imageshack.us/img208/4964/storyb.png

On a more serious, sciencey note - Magma dropped from the reservoir has some very interesting behavior.  Any benefits I accrue from the pressurized pipes disappear immediately as it falls to the ground.  The spread speed is very slow, as you might expect, and the form the magma pool takes after the initial settling is over is a DOME of magma, 15-20 tiles in diameter.  When I say dome, I mean the magma actually supports more magma a z-level above the drop point in a fairly stable configuration.  When the drop is not far along, the magma briefly stays at yet another z-level above ground.  The net effect is something akin to the topography of a sunny-side-up egg, with a large flat disc surrounding a bulbous lump of magma in the middle of the drop point. 

From this I conclude that there are only two effective ways to use this trap system as it stands - one, to center the enemies at the drop point.  This will encase them in magma and offer the sweet spectacle of both drowning and burning at the same time.  This, incidentally, is how the test went. 

Two, multiple gates surrounding the enemy are opened, surrounding them in a gradually widening flood of magma that traps them in the center, eventually closing in to immolate them.  This I haven't tried, but I'd anticipate pressure issues after about 20 seconds of flow.  The rate of replenishment is not very high if we're talking about constant flow rate, and especially near to the source pump there's not a lot of magma in the tubes to draw on.  Farther away, this might work better. 

The bonus third option is one that I'm researching right now.  I'm constructing a 46-pump water elevator to fill an auxiliary network of reservoirs from the brook, adding a cave-in-gun functionality to the reservoirs.  The brook is rather far away from existing construction, and the elevator is a lot of work, but I've got the initial 10-waterwheel pumping station constructed and active.  I sketched out a design for the water dispensing mechanism utilizing bridges to avoid having obsidian "kidney stones" (thank you, dwarves in dwarves megaproject) form and block the pipes.  I'll post it once I've constructed an example.  If anyone has bothered to figure out how to stop caveins from pause-recentering, I'd appreciate the procedure. 

Added in the framework for most of the A-ring, and filled several more stations.  At this point, it's actually looking like a viable defensive mechanism.  I'm still very pleased with the fill rate, although it is starting to take longer to repressurize after adding on a new section.  Still, the ability of the network to move magma to the endpoints is very strong and speedy - opening a gate in the pressurized system results in magma covering 12 tiles of 2x2 hallway in about as many program steps.  This has made me realize that my initial calculations about how much magma would come out of an opened reservoir are going to be way off.  Even with the pipe floodgates in place, the magma dispensed is going to be another 3/4 reservoir worth - and without the floodgates, it's more like 10 reservoirs worth as every pipe in the chain discharges into the open reservoir. 

I revised my layout a little to eliminate some extraneous linkages and make the extremes of the network more equidistant from the central tap.  I also added some work gantries to the plan so that my dwarves can path more efficiently to the various stations.  Hopefully I get a siege soon so that I can test this sucker out.  I've had some kobolds and snatchers, but they're pretty much dead by the time they decloak due to various traps and animals I have lying around my entrance. 

As you can perhaps see from the image, today my project was mostly to test the fill behavior of the reservoirs.  As it turns out, I learned some interesting stuff - maybe it was generally known, but I certainly hadn't had reason to look it up prior to this point.

-A screw pump, when pumping into a confined space, will pump until the space is as full as it can get and then cease to move liquid forward.  The other possibility I had considered was that it would continue to pump forward, either pressurizing or destroying the liquid that passed through.  This is a much more advantageous option for me, as it allows the system as a whole to "fill" and maintain maximal magma storage. 

-Magma does not (whew) leak through open space above aforementioned confined spaces when there is a power conduit of some sort (in this case, windmills above gears/pumps) filling the space.  I cannot testify to what would happen without the power linkage, or with water, or in any other direction, and am not responsible for the ramifications if someone decides to overpressure a small room in their own fort to see what happens. 

I also decided on a lever grid setup.  I have three lever rooms, spaced where I found a large enough uncluttered area throughout the fort.  They are all laid out in a miniature diagram representing the hexagonal layout of the reservoirs themselves.  The first one is the Fire Control Room.  This one has a lever for every reservoir, and opens the bridge at the bottom to dispense death and destruction.

The second two rooms concern the flow of magma throughout the grid.  After lots of thought and whiskey, I decided to arrange the grid in a more or less concentric pattern for as long as I could.  Every hex is designated by its distance from my fortress entrance.  The magma pipes that connect WITHIN a distance ring are the primary outflow of the reservoir, and are controlled from the Upper Flow Control Room.  The magma pipes that feed BETWEEN distance rings are the secondary outflows, and are controlled from the Lower Flow Control Room.  Not every reservoir has a secondary outflow, so the grid is a bit patchy.  I'm thinking of subbing in orthoclase floor tiles to represent the leverless stations just for visual completeness.

Lastly, I dedicated some time to roofing over and otherwise modifying my fortress entrance so that I could literally dump lava right on top of it and be good to go, as well as ensuring that the entryway was raised up so as to deny entry to any incoming magma flows without the need for gate systems that I will inevitably fail to activate. 

Completed the initial pumping station, as well as the first two reservoirs in the chain, although I might have to go back and modify them so they effectively fit with the rest of the network.  I've decided to go with all-at-once building, since it's easier to incorporate the pumps as I go than it is to have the masons complete things first.  Also, I get to iron out the quirks before I've left myself with 50 reservoirs to redesign.  Pictures follow:

Here's the layout as things stand - the first two stations complete, plus the initial tap and the makings of a third station. 



The bottoms of the reservoirs ended up looking pretty badass.  I went with iron doors, bridges and hatches on all of the reservoirs, since I'm swimming in it - I've got two magma forges turning out iron on repeat, and the mountain has it riddled through.



And here's the top of the canal, which serves as a conduit for my workers to access the various stations.  The windmills that power the various pumps incorporated into the reservoirs are seen at this level, which I think looks pretty awesome.  Luckily, I have a really windy clime - they're putting out the max power of 40 per mill, which is highly convenient.  If I ended up doing 20 per, or none, I had hatched a plan to set up a reactor core in the center of each hex and radiate axles out - which, now that I'm saying it, sounds awesome - but it's so much easier to just plop on a windmill for the time being.