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
Diocleides 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.) in width, with each side over 125 feet (42 metres approx.) high. It rested on eight, high wheels, allowing mobility, and it also had
casters to accommodate lateral movement. All exposed sides of the helepolis were rigidly defended; iron plates protected the wooden structure from possible inflammation, and additional defences, such as great stretches of
hide plastered on the interior, were placed to withstand the power of
ballista and
catapult assault. The inside of the machine was divided into nine separate stories, each accessible through a long flight of stairs that wound from the ground floor to the very top. Over 3,600 men were needed as crew, working in relays to drive the helepolis, which weighed over 160 tons.
The siege Despite the seemingly indestructible design of the Helepolis, many of the iron plates were dislodged during the siege, rendering the great machine highly vulnerable. Fearing that the laboriously constructed Helepolis would fall victim to the intense fire that was directed towards it, Demetrius I of Macedon ordered that it be withdrawn from the war field to prevent any further damage. Following a long period of assault, the siege was abandoned after it was realised that the fortifications of Rhodes were too powerful and well defended. Among other uniquely designed siege machines employed by Demetrius was a giant
ram over 60 metres long, requiring over 1000 men to operate, and which was also designed by Epimachus of Athens. After the siege, the Helepolis was abandoned near Rhodes, despite Demetrius' desire to keep it from harm during the Siege. The people of Rhodes melted down its metal plating and used the materials to build the
Colossus of Rhodes. ==Notes==