sentences:  The design for the Helepolis was based on that of an earlier and smaller siege machine, used against Salamis at around 305 BC, but it was Epimachus of Athens who actually co-ordinated the construction of the siege machine.Assuming the figures recorded in the writings of several ancient historians, including Dioeclides of Abdera, Vitruvius and Plutarch are accurate, the Helepolis was and remains the largest siege machine ever erected; it was a colossal, tapered, tower-like structure 60 feet (20 metres approx.