My initial assumption was that if something died on a weapon trap, there was a chance for it to jam, regardless of what dealt the killing blow. After testing with a unit of Crossbowmen and some wooden traps, I've concluded that
the weapon trap itself must score the killing blow to jam. Therefore, a weapon trap that does not have the capacity to kill, does not jam. But, a weapon trap that cannot kill almost seems to be defeating the purpose. If the weapon trap could mangle to the point of being
basically but
not dead however, that would leave the enemy a trivial matter to clean up for even a raw recruit, and the weapon traps would remain unjammed to
horrifically disfigure process any remaining
victims opponents. Under the usual pretense of "morality does not matter when !!SCIENCE!! is underway", I assembled my prisoners in the chamber pictured below.
Within the four main cages are two Muskox Men, a Muskox Woman, and a female Ologhai captured from a siege. Surrounding the central containment are weapon traps loaded with ☼Masterwork☼, ≡Exceptional≡, and *Superior* quality Bone Battleaxes crafted at the Boneforge.
(Note: The value of the bone does not seem to factor into the edge quality. I noticed no difference between the edge of a Cave Tortoise bone and a Giant White Tiger.) In the southwest corner there is a giant coyote that has been made into a Smoke Zombie from the evil clouds outside. It will provide incentive for the prisoners to move around the chamber and trigger the traps.
Upon release the Muskox Woman stumbled over a trap, and on the first trigger there was a great deal of bruising and tearing, but there were two wounds of note, primarily the right lower arm, which had its sensory nerve severed. Secondly, she was struck in the lower body, causing her to become sick. An opponent who is puking their guts up is a much easier target. She triggered the trap a second time, and again the damage was mostly superficial, but one of the axes managed to catch her in the throat, tearing apart the skin and opening a major artery. Upon the third and fourth trigger a sensory nerve was severed in her left arm and she succumbed to pain. At this point the giant coyote had gotten to her and any further data is corrupted by the damage it caused.
The first Muskox Man was a similar story, the first trigger resulted in labored breathing, a severed ear, and significant bruising/lacerations. The second and third triggers followed the pattern of causing them to become sick and subsequently pass out, presumably from accumulated bruising/laceration pain. As the triggers went on, more and more arteries and nerves were severed, both sensory and motor. Exposed small areas of the body (nose, fingers, ears) were subjected to crushing and severing. Perhaps the most significant wounds were a strike to the left hand which resulted in ligament tearing and motor nerve and artery severing, and a strike to the right lower leg, with the same damage as the hand. At this point the coyote ripped his throat open so no further data can be reliably collected.
The second Muskox Man was struck in the head by one of the axes and was immediately knocked unconscious and killed by the Ologhai. It is worth noting that the axe was only able to knock him out, and did not jam.
The Ologhai was struck in the throat on her first trigger and it was "cloven asunder", resulting in rapid exsanguination.
Those who did not succumb to their cohabitants died from blood loss, either from a direct shot to the throat, or in wounds comparable to the chinese execution method of Lingchi, with many small cuts causing a great deal of collective bleeding. It is also worth noting that Muskox Men and Ologhai are roughly three times the size of an average dwarf, so the traps may be even more effective on the exposed areas of smaller races. A hallway filled with bone battleaxes seems to perform spectacularly against lightly armored opponents, though I will need to wait for another siege to test their effectiveness against armor. It is safe to say that any uncovered area will be reliably mangled (but not result in death). However only the ☼Masterwork☼ and ≡Exceptional≡ weapons performed well consistently, and I would not recommend using anything less than either of those qualities in your traps. Although you may ask why I didn't use blunt instruments, a blunt weapon has a better chance of causing instant death through blunt force trauma to the head, and the goal here is to avoid a killing blow via weapon trap.
Preparations for a similar chamber filled with rock weapons is underway.