Reference posts:Internal physics of minecarts:
http://www.bay12forums.com/smf/index.php?topic=112831.msg3536975#msg3536975Velocities of falling creatures:
http://www.bay12forums.com/smf/index.php?topic=117154.msg3751309#msg3751309Exploding grizzly bears with a watergun:
http://www.bay12forums.com/smf/index.php?topic=119831.msg3839178#msg3839178http://www.bay12forums.com/smf/index.php?topic=119831.msg3841445#msg3841445Device description:1. Make an "exploit ramp" linear minecart accelerator, ideally 30-50 tiles long. At the "muzzle" end should be a 1-tile-long hole, followed by a fortification (this allows a minecart to pass through the fortification because it is airborne). On the far side of the fortification should be a 1-3 tile long space (a hallway or room) in which is the victim. There needs to be a solid wall just behind the victim.
2. Load a single supermassive minecart. A platinum minecart full of platinum stuff, native platinum boulders, or if possible cheat-mined slade boulders. Anything to increase the cart's mass. Bonus points to readers who can come up with heavier carts.
3. The cart accelerates down the track and strikes the victim. Minecart collisions roughly preserve momentum, so if the cart is heavier than the victim, the victim gets tossed really fast. This can cause the victim to "slam into an obstacle and blow apart".
Mechanics:If the victim strikes a surface at velocity 200000 or faster, it will blow apart (tested in arena using DFHack to modify velocity).
I modded minecarts to hold very large volumes of stuff, and then filled a minecart in arena mode with several giant sperm whale corpses. I then used DFHack to accelerate the minecart to velocity 270000:
The iron minecart strikes Giant Sperm Whale 2 in the upper body, bruising the muscle and bruising the left lung!
The Giant Sperm Whale 2 slams into an obstacle and blows apart!
Giant Sperm Whale 2 has died after colliding with an obstacle.
So the physics is there, waiting to be exploited. This weapon should kill anything that can die from decapitation, instantly.
A platinum minecart full of 5 native platinum boulders weighs 11556 kg.
A platinum minecart full of 5 slade boulders weighs 100856 kg.
Giants weigh up to about 14000 kg as measured in the arena (but many are less). Giants are size 9000000 creatures.
Giant sperm whales (size 200000000) weigh around 300000 kg. See
http://dwarffortresswiki.org/index.php/DF2012:List_of_creatures_by_adult_sizeSo platinum boulders would allow you to explode most non-megabeast creatures. Slade boulders would allow you to explode organic megabeasts and organic FBs/Titans, but not whales or inorganic large creatures.
Fun Falling Mechanics:air accelerate 4900/tick
water deaccelerate 5700/tick
magma deaccelerate 8100/tick
26+ z-levels to blow apart in 41+ ticks
50+ z-levels to max velocity in 56+ ticks
So if you fall 10z, and land in water shallower than 10z deep, falling damage happens
Water needs to be 44z deep to stop damage from a fall from any height
EDIT:
I just verified that a few cages containing large numbers of massive creatures can be loaded into a minecart, bypassing the volume restrictions on minecarts, and allowing any fort with sufficient caged creature mass to build the above weapon. The downside (upside?) is that the caged creatures will be released on impact due to the shotgun effect. The creatures need not be tame or friendly, just heavy. This isn't necessary for smashing humanoids like goblins, since an empty iron minecart is sufficiently heavy to explode them.