A Study on Possible Motors for Siege Towers

This paper studies the motion of the ancient siege tower. Many considerations and different pieces from the classics strongly suggest that those war machines were powered by internal motors; for this reason, the authors examine some mechanical systems, all certainly used in the Classic Age, that could be easily adopted to power the siege towers. This war machine was first used in Europe by Greek engineers and called Helepolis (⁠$ε`$λ$ε´$πoλις, “taker of cities”); however, there are earlier examples of siege towers built in Mesopotamia. First of all, some pieces from Classic authors have been reported in which it is possible to find several traces on what we propose. Then some possible ancient motors suitable to be installed into the helepolis are proposed: capstans, tread wheel motors like the ones used by the Greek-Roman cranes, and counterweight motors. The proposed motors are also analyzed from a mechanical point of view in order to examine, at least theoretically, their effectiveness in such applications. Results obtained by a simulation with a Working Model 2D™ model showed that the proposed device is certainly possible and also suitable and effective.