New HFS defense. Minecarts full of lead bars travelling down a 200 z-level ramp to the circus.
I thought of something like this, but a little different (and less reliant on the unknown matter of acceleration being capped or not):
Minecart-based DIY catapults. Say a goblin siege comes to your fort and is waiting outside your sealed-up front entrance. You have a fairly respectable tower built up above the main hall.
tower
_______
| |
| |
| |
| |
| |
| |
| |________
| X_/
| |
| <- main entrance
|________________ g goblins g g g
The X_/ is a ledge inaccessible from the ground with an open port leading into the tower, and an upward ramp on the end. This portway is connected to a long straight series of ramps in the (necessarily broad) tower, at the top of which is a stockpile of minecarts and lead bars.
When a siege comes, and stands waiting outside the fortress main gate loitering, the dwarves are sent up to load a minecart full of lead bars, and push it down the ramp. The cart full of lead bars rockets down the giant tower-ramp until it reaches appreciable speed, then shoots out the port above the entrance hall and sails off the ramp. It flies a distance that I'm hoping will be fairly predictable (and therefore, reproducible) based on the load of the cart and the height of the tower from which it's dropped, and then crashes down into the middle of the goblins, smashing at least one and hopefully several of them to pieces. The dwarves in the tower continue loading lead-filled missiles with impunity until every goblin in range is a chunky splatter.
Depending on how tracks work out -
Can you have interconnected track lines, that is to say, a system where a track could have "tributaries" that lead into it and join into the main line? Such that you could have, for example, three starting branches in a line converging into a single ending segment? - you might even be able to have multiple launching stations at varying heights up the tower feeding into the same main ramp, so that you could order the carts deployed from different ones to hit different distances away from the tower. (Depending on if the load of the cart affects the gain in speed, and how much, you could vary your shooting distance this way as well).