Helepolis

Helepolis (Taker of Cities)
A Helepolis-like Siege Engine showing catapults, stairs and movement capstan.
Type	Siege tower
Place of origin	Ancient Greece
Production history
Designer	Polyidus of Thessaly
Specifications
Mass	160 short tons (150 t; 140 long tons)
Width	65 ft (20 m)
Height	130 ft (40 m)
Crew	3,400
Armor	Iron plates
Main armament	2× 180 lb (82 kg) catapults 4× 60 lb (27 kg) catapults 10× 30 lb (14 kg) catapults
Secondary armament	4× dart throwers

Helepolis (Greek: ἑλέπολις, meaning: "Taker of Cities") is the Greek name for a movable siege tower.

The most famous was that invented by Polyidus of Thessaly, and improved by Demetrius I of Macedon and Epimachus of Athens, for the Siege of Rhodes (305 BC). Descriptions of it were written by Diodorus Siculus,^[1] Vitruvius, Plutarch, and in the Athenaeus Mechanicus.