Epimachus of Athens Epimachus of Athens ( , c . 300 BC ) was a renowned Athenian engineer and architect who is known to have constructed the Helepolis ( literally , " Taker of Cities " ) , a huge siege machine first conceptualised by Demetrius I of Macedon and built to be employed in the unsuccessful siege of Rhodes . Life . Few particular details are known about Epimachus of Athen ' s life . He built other unique siege weapons , aside from the Helepolis , some for Demetrius I of Macedon , and others for various other leaders and warlords . Of these other siege weapons was a large battering ram over 60 metres long . Many of his creations had visible effects on future siege engineering , hundreds of years later , and the design for the Helepolis in particular had effects on future designs ; the term Helepolis endured for many centuries after the " original " , used for any similar , tower - like siege machine . The Helepolis . 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 . ) in width , with each side over 125 feet ( 42 metres approx . ) high . It rested on eight , high wheels , allowing mobility , and it also had caster s 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 . In addition to being strongly defended , the helepolis was powerfully armed ; several catapults and balistas were placed on each of the floors , each outlooking the battlefield through large shutters . On the higher floors , dart throwers , among others , were stationed . 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 .