Roman Barrel Vault

The Antonine Baths at Carthage were the fourth largest of all Roman thermae and were the largest outside of Rome proper. These baths were commissioned by Emperor Hadrian in 146 C.E. and completed by his predecessor Antonine Pius in 162 C.E. At the time Carthage was the third largest city in the Roman world. Situated on the coast of Carthage overlooking the Mediterranian Sea, the baths’ unique location required a deviation from previous bath complex construction styles. Given their close proximity to the sea, the usual practice of excavating a basement was not an option. Consequently, the builders engineered the structure with the ground floor functioning as the service area basement and the baths then constructed above it. What mostly remains today at the site are these areas where the hypocausts (a space into which hot air was sent to heat a room or pool above it) were located. Here exists some the finest examples of functioning Roman barrel vaults in their varying forms and uses.

In the image provided, it appears builders used keystone-shaped, linear stones in a series of impost blocks to create the rounded portion of the upper half of the vault. This technique would have provided a superior level of support for the imposing structure that potentially existed above it. In another example of a barrel vault used at the site, the upper portion of this vault appears to be composed of conglomerate rock and concrete. The space beneath this vault is deeply trenched, which is assumed to have functioned as either areas for a furnace or running heated water. Though still very sturdy, this vault type seems to have afforded less support for what may have been positioned directly above it.

What is most important about the Roman vault in general is that this was a departure from the uncomplicated arch used previously in construction. This shift from a simple archway to a vault demonstrates the spatial intelligence Romans began to realize and practice in construction and design. From here they would go on to create and perfect the groin vault and ultimately the dome. It was this mindset and forethought that shaped the Roman culture and their pursuit to achieve order and perfection. The Romans in this quest have left us an architecture that is in its precision a true reflection of its creators.