Rhodes, 304 BC.
Demetrius Poliorcetes’ Movable Siege Tower
Reconstruction: Museo del Sidecar, Cingoli (Macerata)
Materials: wood (oak, sessile oak, spruce), iron, hemp, vegetable ropes, lead, natural glues
Described by the sources as the largest ever built, the nine-story siege tower by which Macedonian King Demetrius Poliorcetes reached the walls of Rhodes in 304 BC was 46 meters high and 23 meters wide. Projectiles were launched from the arrow slits. Covered with metal to prevent it from being set on fire, it concealed the propelling mechanism. Transversal axles, activated by an enormous winch, directed the advancement of eight wheels. To change direction it was necessary to release the wheels, rotate them 90 degrees and put them into the perpendicular axles.
A memory of this set of movements remains in the game of chess, where the rook can only move forward or sideways.