My siege engineers are too scared to do their job. What am I doing wrong?

Note I'm playing a succession game using version 40d.

So I've set up a Maze of Death with a nearly a score of ballista at the ready to fill invaders with pointy death. Unfortunatly my ballista operators run up to fire the ballista, realize they're about to shoot some goblins and flee. what am I doing wrong?

Solution 1:

The problem is that they have line of sight to the goblins. Siege Engineers are just like any other dwarf civilian, and will flee from danger.

Unless you're lucky enough to acquire a forgotten beast syndrome that causes your dwarves eyes to rot, you're going to have to engineer a setup where your dwarves won't see their targets. (As unintuitive as that sounds, just roll with it. They're dwarves.)

In practice, this just means your ballista are too close to your maze of death. The wiki suggests that moving the siege engines back 10 squares should be sufficient.