By Heron of Alexandria, Mechanics, book III.
Construction, loading and unloading materials.
The crane is comprised of only one beam that can be inclined when necessary and is held in place with three cables. Along the crane’s mount is a spiral-wrapped rope that served as a grip to help the operators climb up.
Dimensions: the height of the device is due to the length of the straight wooden beam which makes up the vertical supporting element; it would have been around 10-12 high maximum.
Reconstruction: the crane is shown with a lower tapered termination, which sits freely in a specially-made base allowing it to move in any direction.