Roman military engineering

Descriptions of early Roman army structure (initially by phalanx, later by legion) attributed to king Servius Tullius state that two centuriae of fabri served under an officer, the praefectus fabrum.

However, when on the march, particularly in enemy territory, the legion would construct a rudimentary fortified camp or castra, using only earth, turf and timber.

The 1st century BC army engineer Vitruvius describes in detail many of the Roman siege machines in his manuscript De architectura.

When invading enemy territories, the Roman army would often construct roads as it went, to allow swift reinforcement and resupply, or for easy retreat if necessary.

Thus, soldiers were involved in building civilian works to keep them well accustomed to hard physical labour and out of mischief, since it was believed that idle armies were a potential source of mutiny.

Soldiers were put to use in the construction of roads, town walls, the digging of canals, drainage projects, aqueducts, harbours, and even in the cultivation of vineyards.

A second example is the massive ramp built using thousands of tons of stones and beaten earth up to the invested city of Masada during the Jewish Revolt.