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Dwarf Fortress => DF Dwarf Mode Discussion => Topic started by: Larix on March 06, 2015, 06:23:30 pm

Title: Soldiers are overrated (non-military defences presentation)
Post by: Larix on March 06, 2015, 06:23:30 pm
The dwarfs of Degelkol, Galleywheels, don't think much of military prowess. Consequently, they have no standing military and in fact no citizens with significant military skill.

That doesn't mean they are pacifists. Their wealth has attracted many goblins and other hostile creatures. To keep themselves safe, the people of Galleywheels have built many traps. However, the items found in the "traps" folder are generally only the backup plan, goblins are mashed by various other contraptions.

N.B. Both Galleywheels and Blamelesscloister are .34.11 forts. I've tested the concepts in .40.24 and they still work, although the exact efficiency may have changed in some cases. Hard to say with un-co-operative goblins who rarely bother to show up.

Exhibit one: automated Atomsmasher.

(http://i.imgur.com/KI3gSoX.jpg)     (http://i.imgur.com/MlqFgYA.jpg)   

Two 3x10 bridges that must be travelled lengthwise. The two doors in the middle enclose one tile of water (pond, filled from above). Whenever a door is opened, water spreads off the tile, the pressure plate in it (responds to 0-5 water) fires and indirectly triggers a 200-step repeater that controls both bridges. Bridges change state roughly every 105 steps. Creatures on the bridges while they raise are thrown around (unless they're on the wall tile, where they get crushed right away), stunning them, often breaking bones and effectively preventing them from moving forward. Creatures in the corridor while the bridges come down are crushed, destroyed with no remains. Very convenient, since it cuts out all the goblinite hauling. Since it's triggered by an opening door, trapavoiders are caught, too. On the downside, it also crushes merchants, diplomats and citizens when allowed.

Between uses, the water cell must be refilled via pond order. That's visible to the right - it's the level above. The traps are the backup in case some flyer gets through the pond opening. The connection between the smasher and the fort is through a raisable control bridge. For added safety, a citizen-triggered pressure plate frequently hinders dwarfs from commiting suicide by bridge - it opens a hatch cover in their path. If the control bridge is up, invaders will not path into the crusher.

To prevent mis-crushes, the repeater is triggered indirectly:

(http://i.imgur.com/wYLIMNp.jpg)

The hatch to the left responds to the trigger, but the cart can only enter the proper activation loop when the hatch in the southeast (orthoclase) is also open. That hatch is controlled by a dedicated "arm bridge" lever.

This was our first defensive machine, and it's been the go-to device when dealing with goblin/troll siege forces. No hauling, little mess, very efficient. It can't be used when an invasion force includes large animals and is useless against semi- and megabeasts (bridges break when trying to lift or crush something too big).

For the big stuff, our recourse was
Exhibit two: spike corridor. Once again, pretty simple:

(http://i.imgur.com/HX7A1KO.jpg)

Doesn't look like much, but these fifteen spike assemblies took out numerous large war beasts, a few titans, a roc and a dragon and two demons. It's run off a minecart repeater tuned to optimum period of 82 steps per full spike cycle. It takes four pressure plates to achieve this, which isn't optimal.
To the north and below, the corridor continues through several weapon traps, which in fact took care of a few particularly nimble victims.

The spike corridor gets triggered by lever-pull and can be selectively shut to the outside world or the fort.

Since the entrance to the spike corridor is rather exposed, we built an extra door just for diplomats (originally also for migrants):

(http://i.imgur.com/VWCAAGP.jpg)

A spider-web of underground tunnels, leading to a bridge-lock, guarded by a few weapon traps and a war dog. Since the entire surface is set to "restricted" pathing, it safely channelled migrants through the underground passages when we still got migrants. Dog and traps take care of ambushes and thieves that try to sneak in with the diplomat.

The caverns under Galleywheels were home to several massive beasts. While it's entirely possible to lure them with an artefact piece of furniture and poke them with spikes, we decided to try out some minecart applications:
with impulse ramps and/or the checkpoint effect, carts can be set to perpetual motion. A sufficiently heavy cart can deliver quite a punch, and with ramps, it can keep giving additional punches after the first one. The first design was a simple accelerator coil, tried out against goblins:

Exhibit 3a - goblin exploder

(http://i.imgur.com/Zd4tQTP.jpg)

Cart circulates counter-clockwise in the six-ramp cycle, reaching maximum ramp speed. When the door to the south is opened, the cart exits, at bone-breaking speed. Anything not substantially heavier than the (metal) cart will be blown apart, but it seems to only hit one opponent at once. The cart is re-cycled by an impulse ramp on the collision spot, sent around the southwestern loop over a hole in the floor (so even if a crowd wants to enter, everyone tries the door instead of going around).

Not fully satisfactory, since with large opposing forces, the cart can get stopped on a flat tile. I think this test device failed half-way through an ambush.

Thus, improvement:
Exhibit 3, high-speed minecart grinder

(http://i.imgur.com/eI9K6wA.jpg)

A twelve-ramp loop. To get the cart around corners without losing ramp acceleration, corners go up a level. On the level above, there's another impulse ramp sending the cart back down on the other side. No matter where the cart collides with a target, it cannot be fully stopped. I built two grinders in a row, in case something got through the first one, and a lockable door and spike array, in case something got through the second. Nothing got through the first so far. Actually, we seem to have run out of forgotten beasts. Yes, that design has killed three forgotten beasts (not at the same time).

The design works against goblins, too:

(http://i.imgur.com/toX1O77.jpg)

And against trolls ;)

To make the whole thing start- and stoppable at will, carts are first deposited on mechanically operated hatches. However, those hatches attract trolls (and forgotten beasts). They have to stand inside the grinder to destroy the hatches, so that's actually still useful, but once the hatch is gone, there'd be no more way to stop the cart. So we _also_ installed one 1x1 retractable bridge in a corner of each grinder cell.

Large crowds can clog the grinders. It seems that a cart can only push one creature per tile, and large/heavy creatures, especially when there are several in one tile (like trolls while taking a hatch apart), can block a cart's movement into their tile.

So, not perfect, but adequate. Can deal with normal sieges.

It's also possible to build grinders with much less floor space - two ramps per cart are enough:

Exhibit 3b - chain of tiny grinders

(http://i.imgur.com/MDezZlK.jpg)     (http://i.imgur.com/eDy1kHm.jpg)

The trolls got to grinder Nr. four out of nine. Once again, trolls clump together to take down hatches, blocking the cart until they spread out again. The grinder chain took out 26 units of a siege, which broke the morale of the rest.

Each grinder cell consists of two straight ramps, nothing more. Since they touch each other, they "lean" in opposite directions. A cart will keep bouncing between these ramps at substantial speed forever, or until offered an exit (above). That's what that mess of doors and hatches is for - it allows extracting the carts from their cells and in fact deposits them back onto their hatches, ready for operation at the flick of a lever. The nice thing about this design is that every tile of path goes straight through minecart-occupied ramps, there's no way to sidestep them.

There's another way of crushing things with minecarts: by dropping from above. Due to a rather weird bug, minecarts deliver collision damage through solid floors to creatures directly below. Out of curiosity, we tried this out against forgotten beasts, as well:

Exhibit four: minecart percussion corridor

(http://i.imgur.com/9VsSJjr.jpg)

A row of rollers pushing west, a tile of floor and a pit. Looks quite unassuming. Carts touch the rollers and get pushed west. Carts coming from floor do not enter downward ramps at all, they always jump. Carts jump past the pit, smack into the wall and fall down.

(http://i.imgur.com/mbUDr1x.jpg)

Into a simple double-ramp pit. After hitting the floor, the carts climb out east, towards the roller that throws them back in.

And on the level below that, through unbroken floor:

(http://i.imgur.com/AlGIjJk.jpg)

Those were six forgotten beasts, of various materials up to gemstone. Ten copper minecarts regularly punching from above >> forgotten beaasts.

I've tried the design against HFS, and it works quite well. Very beefy types can take quite a lot of punishment, but if you manage to keep them under the carts for long enough, they should succumb eventually. Haven't tried it against goblins, feels like overkill. Percussive minecarts can be had without power, too.

Something i haven't built in Galleywheels, but which also works remarkably well:

Exhibit 5: powered minecart grinder

(http://i.imgur.com/43qrjGL.jpg)

The six roller pairs in the centre-south are the grinder. Each roller pair tosses a heavy, massively loaded cart back and forth when powered. Nothing gets through. This simple setup has taken out 444 units (mostly hostile) so far. It's backed up with traps and coupled with bridges to offer an alternative path and/or block path through a busy grinder - to keep traders alive. It's built in a glacier with practically no planning, thus the spaghetti pathing.


The main downside of automated defences is that they're largely static. The best magmacannon does nothing for you when the goblins aren't in the target zone. Waiting for the enemy to enter your prepared crusher/spike corridor/trap field can become quite boring. Fortunately, most creatures with legal path _will_ move at some point. And if they just won't, you can always flood the area with magma.

(http://i.imgur.com/dR2N2sq.jpg)
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Terff on March 06, 2015, 10:23:06 pm
This is glorious, as a person who hates setting up military this sounds delicious
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: YAHG on March 06, 2015, 10:24:20 pm
My favorite is the percussive minecarts.  :o
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Cattani on March 06, 2015, 10:33:08 pm
This is inspirational. Feeling like returning to the older version and try learning minecarts because of this. Thanks for the motivation!

I feel like I'm enjoying some 60% of game content at most because of minecart ignorance. It's hard being lazy.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Max™ on March 06, 2015, 11:25:03 pm
Worth noting that a lot of formerly safe designs are rendered null by climbing and jumping.

What's interesting to me is that I see enemies jump a couple of tiles across the edges of murky pools when I'm kiting them around one to get some space, periodically I'll catch a flash of blue background on something which nothing else is close enough to hit, ergo they jumped.

Similarly I had my full-plate parkour dorfs including one disproving the old "untraversable ramps are safe" idea that I have since tested in adventure mode. Gotta make something that has to climb back UP through the untraversable ramps to keep out climbers while allowing wagons to pass freely.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Larix on March 07, 2015, 09:00:55 am
These designs are DF2014 compatible - they all have very strictly controlled entrances that can't be bypassed with climbing or jumping. The only other entrance to the fort is the underground caravan entrance which touches the edge between two trees. This makes it completely inaccessible (to non-flyers) from the rest of the map for DF2012, but the raising bridge across the caravan path and an "airlock" of two door-blockable passages with a bunch of cage traps between them gave sufficient security against the freak goblin squad that spawned on the caravan path. It should still be possible to construct a hermetic seal for the caravan path with bridges.

A fully no-soldiers fort really depends on very strict pathing control, which can be easily achieved by burrowing into the ground and having few if any outside installations. That's more of a limitation in DF2014, where wood and fruit from aboveground trees are a very attractive ressource.

By the way:
I'd very much like it if we could have an invention exchange.

If you (anybody) have made clever, simple, ingenious or silly automated defences in a recent fort, why not show off your work? Anything that's not just a trap field or training room ;)
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Naryar on March 07, 2015, 09:37:00 am
I have tried magma guns, but none of them worked due to minecart slowdown in magma. I believe magmafalls are the solution.

I do believe I should be able to do some non-standard magma traps as well.

The minecart designs seem good. Not fond of atomsmashers as defensive traps though. They trivialize the game.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Spehss _ on March 07, 2015, 11:26:36 am
The minecart percussion corridor sounds amazing. I'll have to try that sometime.

I have a concept idea for a trap corridor where a line of automatic water cannons launch water blobs into a corridor 1 tile wide, with grates as the floor to allow the water to flow back into the cannon to be reused for ammo. The goal is to have goblins have to path through the corridor and getting smashed into the wall opposite the water cannons and get blown apart. Basically have goblins run perpendicular and only 1 tile away from the mouths of however many water cannons it takes to line a corridor, so they get shot at pointblank range with a super-heavy ball of water traveling at max velocity and get knocked into the wall and blown apart by the force.

I have yet to set anything up though, because I have neither the experience with building such minecart contraptions nor do I have the time or dedication to see the project through to the end.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: milo christiansen on March 07, 2015, 03:19:09 pm
I build something called a "seesaw of Armok" when I want a big trap. It is something like your "minecart percussion corridor", except instead of using power to control the cart it drops it from above and uses a bridge to keep it from escaping the pit until I want to shut it off.

The design is more complicated because I use the same lever to contol both the bridge and the hatch cover.

The system works like this:

The lever is flipped, raising the bridge (one z up) and opening the hatch cover (two z up), this drops the cart two z onto one of the ramps.
With the bridge blocking the floor above the ramps the cart oscillates rapidly (eg everything dies).
When the lever is flipped again the cart leaves the pit, crosses the bridge, crosses a pressure plate crosses an impulse ramp and the goes up a normal ramp (this ramp is covered by a second hatch cover that is linked to the pressure plate). Once it is up on the next level it continues down a relatively long track until it hits a ramp with no upper exit, neatly turning the cart. The cart then goes back, crosses the hatch cover and ends up parked on the hatch cover it started on.

The activation delays of the various parts means the cart cycles through the system twice before stopping, as the upper hatch cover takes that long to close.

Sorry no picture, I don't have a save handy with one built, but if you download Rubble (see sig) the "addons/User/Macros/Milo's Entry" directory has image blueprints (including an annotated .xcf with build instructions) of a fortress entry that has one.

I got the idea (and name) from a Masterwork community fort, I forget who was running it, but it was pretty cool.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Max™ on March 07, 2015, 09:29:55 pm
I uh... never got to fully use my back-up defense.

Largest siege was about 5 years in and I think it was like 80 gobs and trolls total, my military at the time had been training for a while, the civvies were all in civilian leather+crossbow or hammer uniforms, and despite having the military stay up on the entrance platform and letting the gobs come to them, Mr. McLegendary and his squad still ended up battling their way down the stairs, past the elevated wagon access (in case of magma flooding) and up next to the open-air cisterns for the dual pump-stack.
Spoiler (click to show/hide)
Worth noting that the troll way to the left by itself didn't come from that direction (the walls direct the magma northward into the forests that way) as invasions tended to come from the southwest, he was actually part of the group making up the trail of bodies down there but one dorf grabbed him by his ear and threw him somehow, earning the name and job Urist McTyson, Trollbiter from me.

I came back with McLegendary and his wife later and activated the pumpstacks while dropping the pistons because why not... there's no place like home:
Spoiler (click to show/hide)

There are a couple of bait targets for trolls that I was gonna test out early on, having a weapon rack and armor stand behind fortifications to see if building destroyers would try to get to them. Turned out the nearby gobs were pretty far away after all.

The two structures to the left and right in the flooded screenshot are the exits for the pumpstacks which link to a set of axles hooked to a 4 wheel reactor. Since the reactor wouldn't shut off even if I closed the hatch over the feed tile I linked a gear from the two axles to a set of rooms full of gears and pumps that suck down enough power to kill it when hooked up.

The pumps themselves draw from a cistern around the forge level which was filled by the volcano, with back-up reservoirs above-ground surrounded by fortifications because it looks cool and I got bored waiting for the gobs to arrive, which is the main problem with not using a military at all... a clean trap corridor is just depressing, a clean military can still be hurled at hell or something.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Niddhoger on March 07, 2015, 09:57:36 pm
These would be more impressive if they weren't largely a long list of exploits.  You can still make pit traps/force mobs to fall 20+ z levels or even use tons of semi-trained animals as fodder (20+ cave crcos and some GCS do wonders for goblin infestations).  However, impulse ramps and atom-smashing bridges are too exploity for me, if you could set up the minecarts without the impulse ramps that would be great. 

The spike traps are fine though, so long as you don't use pathing abuse (opening/closing doors to force gobbos back and forth over them).
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: RocheLimit on March 08, 2015, 01:00:52 am
While I mainly use a military for the surface attacks, I go with an automatic cage trap system for the caverns.

My comment as a complete description of it, but to summarize it there are two main lines of capture; the initial basic cage hall & the building destroyer halls.  A silk-cage trap hall is added later when a GCS or a web FB is caught.

Here is my current trap system, with 8 captive FB's. 
Z=+1 Water cells above each FB holding cell of the trap, and levers for controlled refilling/draining.
Spoiler (click to show/hide)
Z=0 Cage hall for cageable cave beasties, building destroyer cells for FB's, and a web trap for cleanup.
Spoiler (click to show/hide)
Z=-1
Spoiler (click to show/hide)

It's not for every fort, but it does it's job very well.

And here is a gif from a prior fort of the system in action.
Spoiler (click to show/hide)

That said, I have been meaning to experiment more with powered minecart halls.  I previously tried a few times in DF2012 to get a minecart water shotgun to work (never succeeded) and I did get an impulse ramp grinder working a few times.  I found cleanup on those systems to be a bear though.  Last one I got to work in DF2012 worked great for the first few sieges, then I could not for the life of me find the proverbial sock: I watched helplessly as my entire fort walked into the grinder. 

I think I need to work more with magma.  I hear it does wonders.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Larix on March 08, 2015, 07:32:33 am
Oh, i like those! The water-plate triggered by a destroyed or opened building is one of my favourite little tricks, a good way to bypass the TRAPAVOIDER tag.


Quote from: Niddhoger on March 07, 2015, 09:57:36 pm
if you could set up the minecarts without the impulse ramps that would be great. 

See motorised grinder near the end. That one uses no ramps at all, and it's the device with the highest kill count.

Anyway, shotguns and high-speed grinders can be set up without _impulse_ ramps, but
1. it'd lose so much cadence it'd be hardly worth the bother
2. it'd still use ramps, and _all_ ramps are exploity, not just impulse ones. Whenever you have ramps of any kind in a minecart circuit, you're getting checkpoint effects (quasi-teleportation when leaving ramps) or fake ramps (cross levels without ramp acceleration/deceleration).

I'm a dwarf of low morals when it comes to minecart construction, i use all options i have.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: taptap on March 08, 2015, 05:18:02 pm
For me the percussion trap is the coolest system and the one requiring least maintenance. Most challenges are likely too easy for Larix, but anyway: Make a magma mist trap, that applies only the magma mist to the target.

I use submerged pressure plates (someone told me, my first step into fluid logic) as well. As you need the other floor anyway, you could also put a hanging submerged pressure plate in the floor above, this has little benefit as a trigger (saves a door :)), though it might theoretically keep it save from fire breath. The door holding fluid above theme could probably be used to make special utility doors. Say a door that allows fast passage (as long as magma hangs in the air before falling, but messing it up for building destroyers) or in a single use minecart evacuation track (ridden minecart in a track with some water opens door and passes fast before magma falls that blocks the path with obsidian).
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Detros on March 09, 2015, 08:25:14 am
Quote from: taptap on March 08, 2015, 05:18:02 pm
Say a door that allows fast passage (as long as magma hangs in the air before falling, but messing it up for building destroyers) or in a single use minecart evacuation track (ridden minecart in a track with some water opens door and passes fast before magma falls that blocks the path with obsidian).
Nice! We need a bunch of starship-like evacuation pods.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: taptap on June 16, 2015, 06:14:33 pm
I have a good trap to offer. Maybe I can do proper !!science!! after all?

1. Magma trench, no ramps at z-2
2. Minecart circuit, with some speed regulation both against too high speeds, i.e. cart jumps over the whole trench, and too low speeds, i.e. minecart falls into trench, z-1
3. Invader path at z+0 (next to the magma trench, so I did in the prototype)

When activated the minecart circulates, bouncing off the magma a few times per round, producing steady magma mist each time it bounces.

This trap design is certified as energy class A+, since no (?) magma is wasted. (It certainly works with the amount of magma, my slow minecart magma lift can handle.)

I have a working prototype, but the speed regulation is still somewhat whacky.

Spoiler (click to show/hide)

Edit: While this works with a holding area, where enemies are exposed for a while, it is likely not working that great for 3 wide bridges or so, like magma mist traps with submerged minecarts bouncing around.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NJW2000 on June 18, 2015, 05:03:47 am
I am totally inexperienced with large traps, but have a volcano, and a river, and have often wondered if something like this might work

M=magma
W=Water
 :)=miner
O=hollow/obsidian

          M
    :) O
          W

 These would be stacked, in a huge column, with a legendary miner on each one. Can I get miners to automine the obsidian, and would this setup even create obsidian? Would depths be important as well?

The intended effect is a column which rapidly fills with stones, which may fall zlvls till they impact many floors below.

Would most of the stone likely be obsidianized? And would the water drown the miners? Would I have to control depth by alternating the design floors with other floors? And would the supply of rocks be fast enough with, say, 8 legendary miners, to have much impact?
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NW_Kohaku on June 18, 2015, 10:12:32 am
Quote from: NJW2000 on June 18, 2015, 05:03:47 am
I am totally inexperienced with large traps, but have a volcano, and a river, and have often wondered if something like this might work

M=magma
W=Water
 :)=miner
O=hollow/obsidian

          M
    :) O
          W

 These would be stacked, in a huge column, with a legendary miner on each one. Can I get miners to automine the obsidian, and would this setup even create obsidian? Would depths be important as well?

The intended effect is a column which rapidly fills with stones, which may fall zlvls till they impact many floors below.

Would most of the stone likely be obsidianized? And would the water drown the miners? Would I have to control depth by alternating the design floors with other floors? And would the supply of rocks be fast enough with, say, 8 legendary miners, to have much impact?

I haven't done them myself, but generally, you want to work with pumps, not miners, and it works better if you put the two fluids above one another, not on the same floor.  The lower one may be best to work with floodgates next to bridges (probably the water) and the one above can be pumps (for slower magma).  That should create a cave-in machine.

If you have them both on the same floor, letting water and magma leak into a tile on the same level, you have the problem of obsidian being created right on top of the exit.  If you have a dwarf right on that diagonal, then the fluids will travel the diagonal to hit your dwarf, which causes obisidianizing of your dwarf.  If you're channeling the diagonal, I'm pretty sure the dwarf pulls the boulder back with them. 
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NJW2000 on June 18, 2015, 12:51:43 pm
Wait, so how would a cave-in machine look? Would the bridges be removed/lifted to let the magma fall?
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NW_Kohaku on June 18, 2015, 02:19:29 pm
Quote from: NJW2000 on June 18, 2015, 12:51:43 pm
Wait, so how would a cave-in machine look? Would the bridges be removed/lifted to let the magma fall?

Bridges do not provide support, which is why you'd use them to funnel water, as any wall touching nothing but bridges will instantly cave-in.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NJW2000 on June 18, 2015, 03:04:33 pm
So the setup

     B
   BOB
     B

with what beneath the obsidian?
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NW_Kohaku on June 18, 2015, 03:32:12 pm
I would make it like the following:

Code: [Select]
Side View:
  ░≈≈░
  +RR+
░~~  ~~░
++D  D++

░ = Wall
+ = Floor
~ = Water
≈ = Magma
R = Retracting bridge
D = Drawbridge

For the purpose of reading this, floors take up every other row.   

The drawbridges can be lifted towards their sides to shut off water flow, and the (magma-proof!) retracting bridges can be shut to turn off the device.  When bridges are down and hatches are open, water pours into the gap in the bottom middle, as does magma. 

This form of design would require pump stacks. 

In practice, it should be capable of easily raining "orbital strikes" of obsidian down on a path that is 2 tiles wide by however big a trough you can reliably pump full long.  Hypothetically, it should be capable of obsidian-casting a slab that slams the whole killzone in a single strike. 

You will almost certainly need to re-carve the killzone upon use, although you might be able to set up optional ramps, where, as each successive floor is hit with a cave-in, it creates a new floor for a new path to the fortress that can be pathed across.  Remember, cave-ins obliterate constructed floors or things like bridges, so building a floor or bridge through the excavated obsidian allows you to easily set up multiple floors that are struck at once.

In practice, this thing is utter overkill for goblins. 
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NJW2000 on June 18, 2015, 03:45:01 pm
Sooo... the retracting bridge keep the magma from falling onto the target, while the drawbridges surround the whole thing?

How would this work against demons?
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NW_Kohaku on June 18, 2015, 04:50:12 pm
Quote from: NJW2000 on June 18, 2015, 03:45:01 pm
Sooo... the retracting bridge keep the magma from falling onto the target, while the drawbridges surround the whole thing?

How would this work against demons?

The drawbridges keep the water from flowing until you let them down.  This whole contraption should be at least 2 or 3 z-levels above the killzone.  (Feel free to put it wherever your highest z-levels are to create zombie raven squishers.)  Also, hypothetically, if you build several of these, and have a positively obscene amount of water and magma being pumped, you could set up several of these in a row, dropping obsidian on 2/5 tiles on the map, barring the column for the water and magma. 

And it works brutally effectively against demons.  In fact, it's basically just a non-checkerboard layout of Aussieguy's famous checkerboard.  If you're dropping obsidian from above, I recommend flooring over the killzone so they don't fly out, however.  The obsidian will crash through built floors.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NJW2000 on June 18, 2015, 04:53:21 pm
Right, so a know design, then? So it works?

I could probably set this on repeat, right, with dwarve? Or would a repeater be better?
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Oaktree on June 18, 2015, 09:58:57 pm
My current fort in 34.11 called Geniushammers has been playing with accelerator coils.  A number of prototype devices have been built around these since they are compact, easy to build, and have a variety of uses.  I also like their quick reaction time to a lever being pulled to open the door - the cart is ready to roll!  Downside is that a coil can only hold one cart at a time, so barring a return system it's a one-shot deal.

First use has been as a basic building destroyer trap.  Heavy (gold or platinum) minecart in a coil and wait for the door to be attacked. (Optionally just hook the door to a pressure pad a two spaces away where the destroyers prefer to stand.)  Cart fires out and you get something's attention at the very least.  Large creatures can take the hit, and I've only bruised or stunned forgotten beasts with one so far.

I have also put a coil's door on a lever and fired it down an open space into an oncoming goblin unit during sieges.  Results are mixed since I have seen the cart only hit and hurt 1-2 creatures.  But I've also seen it pinball 4-5 creatures into each other and also directly hit a Goblin Elite Archer in the head.   8)

Second use has been as a light anti-intruder trap as part of some in-depth defenses.  An wide open area has a coil at the north end which will fire the cart south - where a curve turns the cart around to send back into a coil.  About 10-16 tiles from north-to-south.  A few of these set-ups are augmented with additional accelerators at the south end to help return the cart to speed after collisions.  Essentially a "frogger" device using a coil to hold the cart at speed until deployment.  Deployed between caravans or just after the ambassadors and liaisons get into the fortress, and during sieges.

Results during sieges have been mixed since hitting a heavy mount like a cave croc can slow or stop the cart on level ground.  Have also seen one tear up most of a goblin cavalry squad by itself.  The device is stellar against kobolds, snatchers, and ambush squads - you just suddenly see body parts and corpses appear in the back end as they get exploded by the collision effects.  However, this device will eat caravan guards and wayward fortress residents.  I have an extra door on a lever to cover the return side - it's the "safety" to totally seal the coil from access, or can be used to stop the cart entirely if necessary.

Lastly, I have a working watergun which uses a coil as part of the main firing mechanism.  It's a standard design with a cart hitting a wall, firing the ball through a fortification on the level above, and then dropping down a hole into a reservoir to be re-filled and then cycled back to the accelerator level to be fired again.

The coil can hold a water-loaded cart which will then fire the initial water ball 3-4 ticks after the lever is pulled.  Cyclic fire rate after that point with a single cart is roughly 92-95 ticks after that point.  I have also experimentally had a second cart dropped into the system and which initially fires about 35 ticks after activation.  This will double the rate of fire, but I have also seen "cart creep" with a cart eventually catching up to and colliding with the other cart to cause a jam.  [Diagrams below]

Water ball trajectories and velocity seem to be variable.  On a range that is 30 tiles long and 5 tiles wide wall impacts occur anywhere from 6-7 tiles down range to balls hitting the end of the range with no side deviation.  (Experimentation in a freezing biome with a water gun has indicated that trying to "ice" targets is a uncommon occurrence and is more like to result in ice walls blocking the field of fire.)

The gun itself is pretty straightforward.  As is dumping the cart into a trench of water that has a reservoir the next level up to keep the trench filled to 7/7 water.  (I fill the reservoir from the fort's aquifer, and also installed drains, etc. so that maintenance can be done.)

The tricky and frustrating part has been getting the ramp and track combinations right that will lift a loaded cart out of the trench, out of the reservoir, and then additionally back up a few levels to feed it back into the accelerators.  That is the main thing I want to get a diagram or picture out of in order to save others the trial-and-error effort if they want to build one of these.

==== Design pictures forthcoming====
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Chaine Maile on June 18, 2015, 11:42:57 pm
This may inspire me to get back into designing my flaming lignite Boulder cannon. I've been away for a while, but still toying with super weapon ideas myself.

I've also always liked to build in some sort of emergency lockdown. For example a large pillar of natural rock suspended over a spiral stair. Pull lever, and something like a magma piston crashes down. This seals all the levels and wings from each other. From there survivors can find emergency picks to dig their way out of quarantine.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NW_Kohaku on June 19, 2015, 09:43:35 am
Quote from: Oaktree on June 18, 2015, 09:58:57 pm
First use has been as a basic building destroyer trap. [...] Large creatures can take the hit, and I've only bruised or stunned forgotten beasts with one so far.

If you want to have a more punch, you should use a setup like Larix has earlier in this thread, where water is stored in a tile above a locked door.  When the building destroyer smashes the door, the water drops, and it falls on a pressure plate, triggering the trap.  Use a second door just behind the first to keep the FB in position. 

The main problem with nothing but a cart on a ramp behind a door is that they have no chance to really accelerate, which means the really heavy creatures don't take much damage.  Making the water-activated pressure plate open a door or hatch holding a cart back, and let it have some room to accelerate, however, and you have a far more deadly cart. 

RocheLimit's post, however, has a great setup for a FB trap, however.  It could possibly use some more manually-intensive expansion, though.  Once trapped, you might set it up for target practice with a sufficiently potent melee force or marksdwarf training if it is not terribly dangerous, or you might set it up for obsidian casting if it is.  (RocheLimit already has a method of getting water into that cell, just add a path for magma, and you can obsidian cast every FB that walks into the trap!)
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Sanctume on June 19, 2015, 11:12:05 am
I am wondering, can burning lignite (block or furniture) combined with a drop of magma starts burning the item to create smoke that can incapacitate or kill creatures in an small enclosed tunnel/room?

z+1: Let's say I have a magma pipe with flow controlled by a magma safe floodgate or raising bridge.
z+0: The level of the close-able  room/tunnel where the invaders path through, and split/separated by a fortification where the smoke can pass through.
z-1: A passage access from inside the fortification to place lignite item below where the magma can drop from z+1.

So it's chemical warfare if smoke can harm invaders.  When invaders path through the z+0 hallway, they are trapped via raising bridges. 
While they are trapped in that enclosed space, release a tile of magma from the z+1 to drop on the lignite items down in z-1.
I am assuming that a burning lignite will produce smoke, and this smoke will travel up at up to least z+0 level and pass through the fortification and suffocate those in the enclosed hall.

Will something like this work?
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NW_Kohaku on June 19, 2015, 03:36:27 pm
Quote from: Sanctume on June 19, 2015, 11:12:05 am
I am wondering, can burning lignite (block or furniture) combined with a drop of magma starts burning the item to create smoke that can incapacitate or kill creatures in an small enclosed tunnel/room?

z+1: Let's say I have a magma pipe with flow controlled by a magma safe floodgate or raising bridge.
z+0: The level of the close-able  room/tunnel where the invaders path through, and split/separated by a fortification where the smoke can pass through.
z-1: A passage access from inside the fortification to place lignite item below where the magma can drop from z+1.

So it's chemical warfare if smoke can harm invaders.  When invaders path through the z+0 hallway, they are trapped via raising bridges. 
While they are trapped in that enclosed space, release a tile of magma from the z+1 to drop on the lignite items down in z-1.
I am assuming that a burning lignite will produce smoke, and this smoke will travel up at up to least z+0 level and pass through the fortification and suffocate those in the enclosed hall.

Will something like this work?

Just put the burning lignite in a 1-tile wide hallway, and make the invaders path through the lignite tile so that they catch fire.  Seems easier.  :P

Just make sure the path is winding enough that they burn to death before reaching your booze piles.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Oaktree on June 19, 2015, 04:06:19 pm
Quote from: NW_Kohaku on June 19, 2015, 09:43:35 am
Quote from: Oaktree on June 18, 2015, 09:58:57 pm
First use has been as a basic building destroyer trap. [...] Large creatures can take the hit, and I've only bruised or stunned forgotten beasts with one so far.

If you want to have a more punch, you should use a setup like Larix has earlier in this thread, where water is stored in a tile above a locked door.  When the building destroyer smashes the door, the water drops, and it falls on a pressure plate, triggering the trap.  Use a second door just behind the first to keep the FB in position. 

The main problem with nothing but a cart on a ramp behind a door is that they have no chance to really accelerate, which means the really heavy creatures don't take much damage.  Making the water-activated pressure plate open a door or hatch holding a cart back, and let it have some room to accelerate, however, and you have a far more deadly cart. 

RocheLimit's post, however, has a great setup for a FB trap, however.  It could possibly use some more manually-intensive expansion, though.  Once trapped, you might set it up for target practice with a sufficiently potent melee force or marksdwarf training if it is not terribly dangerous, or you might set it up for obsidian casting if it is.  (RocheLimit already has a method of getting water into that cell, just add a path for magma, and you can obsidian cast every FB that walks into the trap!)

The cart wasn't just sitting on a ramp.  It was in a coil accelerator - so it came out doing close to maximum cart speed.

My preference for forgotten beasts in any case is connecting an "air lock" between the fortress and each cavern.  In the lock area are 3-4 cells that can be closed off by a bridge and baited with a stone door and rigged with upright spikes and spears connected to a lever.  When a new beast appears the outer bridge is opened, a cell is left open, and I wait for the beast to come after the door.  Close the cell, close the outer lock, and then spike/spear the beast to death.  Might need some decom work if it has deadly blood, otherwise just process the corpse afterwards.  A previous fort had disposed of 20+ forgotten beasts this way.

I prefer a mix of menacing spikes and spears since it appears that spears have a better chance of triggering a de-limb hit.  Which is a necessity for killing inorganic beasts since you need a decapitation or body-splitting hit to kill them.  Which can take a while with this set-up.
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: NW_Kohaku on June 19, 2015, 04:24:26 pm
Speaking of which, my new cavern trap is a GCS web factory with drawbridges to dump them on cage traps.  I have a airlock-style system with a winding passage that leads to a wooden door, a stockpile with a pot of prepared cuttlefish, a barrel of dwarven wine, and a third passage that leads to a guineacock.  It also has three passages that form a shortcut to trap even just random wanderers.  (I'll work on clogging some of the alternate passages in the caverns when I get a more mighty military to ensure more through traffic.)  As a final failsafe, I can raise a drawbridge near the guineacock to trap it inside, with the guineacock pastured but with a pressure plate it can trigger that raises the trap.  (So it runs -> hits plate -> raises bridge that traps webber FBs in trap with the sacrificial guineacock.)

I know it lies outside the bounds of the purpose of this thread, as it uses just "vanilla" traps, but it's almost disturbingly effective at vacuuming up the fauna of the caverns.  (I have a breeding pair of cave crocs, a GCS, a half-dozen naked mole dogs, and a couple giant toads in just a year of operational time.)
Title: Re: Soldiers are overrated (non-military defences presentation)
Post by: Oaktree on June 19, 2015, 04:24:42 pm
As promised, some diagrams for the water-gun design.

Code: [Select]
SIDE-VIEW DIAGRAM

         h          F   ---> targets ---> oX
       [^^^_[^^^]D_oXXX
           ^       |
            ^_^    |
               ^^  |  ---- water filled ---
                X^^^X ----------------------

Legend:
F - Fortification
o - Hole
^ - Track Ramp
D - Door
[ or ] - 180 degree track turn (two pieces of flat track)
_ - Flat straight track
| - vertical shaft
X - Wall

TOP-VIEW DIAGRAMS

01. Firing Range is skipped - it's a hole, a fortification, and where you want the targets to be on the level above the gun.  Holes to act as drains for water are a good idea.  Plus a way to trap invaders.

02. The Gun (Level 0)

   [iii__[iii]D_o::
   [jjjv:[___]

Accelerator Coil that will fire cart east to hit wall and fire contents before cart drops down shaft.  To the west the cart returns via ramp at "v" and then proceeds across series to impulse ramps wrapped around a switch back.

Legend:
i - impulse ramp (NE)
j - impulse ramp (SW)
v - downward ramp
: - wall (surrounding walls not shown)
_ - straight track
[ or ] - curved flat track
D - Door (Control Point A) - connected to lever
o - Hole.  Top of shaft leading directly to the reservoir

======
03. Level -1 - Only showing lift section

         [v
        i]

Cart enters from east, transits flat "S" curve, and then climbs a track ramp (NW)

======
04  Level -2 - Only showing lift section

          i_ivv

Cart enters from east, transits a NW ramp and then a NSW ramp in a half-checkpoint configuration.

======
05  Level -3 - RESERVOIR

             iivvv_____
             __________
             __________

Cart emerges from trench and crosses two NW track ramps to leave reservoir

======
06  Level -4 - Loading Trench
           
               iij

Three NW track ramps.  Cart dropping down shaft should land on (j) and then roll west

Having transferred it to paper (so to speak) and looked it over I can already see some potential improvements to test that might improve the firing rate:
1. Make the drop one less level.  That saves a level of lifting and a partial tick of the cart falling.  You have to monitor the reservoir levels a bit more closely regarding overflow.
2. A "slower" cart might actually transit the lifting zone quicker via an impulse elevator set-up as compared to the brute-force approach.  Though I think that is necessary in the lower levels due to the need to move the cart through water.