Well, that was fun but it doesn't promise too much for actual defence applications.
new movie:
http://mkv25.net/dfma/movie-2744-perimeterguntestshotThree minecarts cycle, each on its own ~ 400-tile long circuit, propelled to max useful speed via impulse ramps. Each cart goes past nine or ten exits, which are normally inactive. Only when a sensing pressure plate is activated will a bridge raise and divert the cart into one of the 28 shot barrels.
The barrel accesses look like this:
Carts travel north-to-south. If a bridge raises, the cart on that track can't go through and takes the corner instead. The extra solitary ramps are to prevent possible collisions between carts or carts being on top of a bridge when it raises.
A bridge raises 100 steps after it gets activated and if activated by a creature, it'll usually only stay up for 110-120 steps. A cart takes about 170 steps for a full cycle, i.e. the "up time" of the bridge must be extended to ensure a shot.
I did that on the cheap, by manual-reset latches:
above below
28 latches, each consists of nothing fancier than a sensor-operated hatch with a minecart on it, with the pressure plate that actually raises the bridge below. Sensor is activated, latch cart falls off the retreating hatch, lands below on the pressure plate and keeps it active until a dwarf comes around to put the cart back on the hatch. Carts here are usually forbidden. This not only means i can easily check if a shot has been triggered, it also prevents my stupid crafters from whisking latch carts away for decoration jobs.
So the cart leaves the main cycle, goes up a few ramps and slams into a wall under open ceiling to release its ammo. The shooting range looks like this:
Each visible downward ramp is actually a gun barrel. A shot was released through the northmost barrel. The shot was triggered by one of the pressure plates in the middle of the picture, i think it's the one northeast of the alpaca, cougar and peahen (white "a", yellow "c" and brown "p"). The unit who triggered it was the yak cow, the corpse of which is visible at the very bottom of the picture. It was apparently busy running away from the other cougar (also a corpse now, next to the "Y"ak remains) that was the only casualty of the shot. There are more trap components (the large sigma sign) out of shot, to the south. The range over flat floor is 70-80 tiles.
The ramps don't cause ballistic launches, because they're not connected to the "forward" exit: barrels shooting south have an EW ramp under them. This way, the cart runs directly into the wall, releasing a flat (not ballistic!) shot, then slides off the ramp to the side. I made it like this to allow an automatic return of the cart to the loading station. The cart return network was probably the messiest bit of work where mining and engraving was concernted. A very small part of it looks like this:
This part services seven of the twenty-eigh shot barrels. The shot feed lines and return lines are -unsurprisingly- interspersed here. At the end of the return trip, the cart is unceremoniously dumped back into the loading station:
Three route stops, three 3x8 weapon stockpiles (no bins, take trap components from copper or silver only). The petrified wood bridge to the north is raised when the gun's in normal operation, to prevent both dwarfs and intruders from pathing into the gun.
No enemies have shown up in well over a year, i'm not really expecting much of this contraption.
In other news, we managed to fulfill a production mandate when the indicator was well into the red. Toy production mandates are fiddly stuff. And a dwarf made a thing - another clothier, another adamantine garment. This time, it was a toga, using two rolls of cloth and two wafers (decoration), resulting in a total value of just over two million.
Total fort value: a bit over 38 Million.
Of those non-adamantine artefacts: 470 000
Artefacts made from or containing adamantine: ~ 17 200 000
Total "architecture" and "displayed" values add up to 11,5 Mio, of which approx. 11 Mio are contributions of "built" adamantine artefacts. So yeah, we may have close to ten million value not counting adamantine.