A cranked windlass of cord and pulleys that hooks to the crossbow’s butt and hauls the string back by main mechanical advantage, spanning prods that no lever could manage. It is slow — a siege crossbow so spanned shoots perhaps once in two minutes — and it is another thing to carry, drop, and tangle. Behind a wall, where the shooter has time and cover, it is worth every ounce.
Spanner, windlass
Cranked cord-and-pulley windlass for the heaviest crossbows; tenfold draw.