Second drum of Trajan’s Column and three tiered sections of the internal spiral
Trajan's Column - an unsurpassed example of engineering - was constructed by the architect Apollodorus of Damascus and inaugurated in 113 AD in the centre of the courtyard between the two libraries of the Forum to celebrate the victories in the Dacian Wars of 101-106 AD. The spiral structure that winds around the central vertical core of the Column is a specific reference to Alexandrian mechanics and Archimedes. In this case, the application of the screw design to architecture serves a specific structural function as it means the weight of every block can be lightened by a third of the whole. The decorative frieze on the exterior winds upwards around the marble blocks covering the spiral, just as water drawn from the river would begin its upward journey inside Archimedes' screw.