The Sundering: Rise of the Witch King is a mod for Medieval 2: Kingdoms and based around the fantasy world of Game workshop's Warhammer universe during the civil war between the Elves, the mod's campaign opens with the Death of Bel Shanaar in -2751 IC.
The opportunity to spear large monsters from a distance or to skewer several man-sized creatures in a single shot appeals greatly to the violent and bloody nature of any greenskin. The bolt thrower, or Spear Chukka as it is termed by Orcs & Goblins works along the same lines as a giant crossbow, which fires a single spear-sized bolt at high velocity. This method of warfare is widely regarded by Goblins as an excellent way to kill things whilst avoiding retribution in return. There is certainly no shortage of crew for these rickety hand-made war machines.