Ancient Roman Underground Engineering: From Cloaca Maxima to Catacombs
Underground engineering was a crucial part of the ancient Roman civilization, as evidenced by their infrastructure and cultural practices. From the earliest tunnels like Cloaca Maxima to the extensive network of catacombs, Roman engineering skills were sophisticated and innovative.
The Earliest Tunnels: Cloaca Maxima
The earliest known tunnel in Rome, Cloaca Maxima, dates back to around 550 BC and was built during the Roman Kingdom. This tunnel served a crucial function within the city's infrastructure: it was a large sewage canal used to purify the Tiber River. Roman soldiers were deployed to quarry the stones and build a barrel vault over the canal, which ran from the Roman Forum between the Palatine and Capitoline hills to the Tiber River.
Tunneling Techniques for Aqueducts and Mining
Subsequent tunnels were designed for aqueducts and mining operations. To achieve the necessary slopes, the Romans used surveying equipment known as a groma. These tunnels were built with great precision to maintain the required incline, which was approximately 0.2 degrees.
When it came to cutting through solid rock, the Romans employed a method involving fire and water. Specifically, they would light a fire on the rock surface. Once the wood was burned to charcoal, they used a piston pump (or siphon) invented by Ctesibius of Alexandria around 250 BC. Water and vinegar were then hosed onto the rock face, causing the stone to crack and fall away.
Building Tombs in Rome
As road-side tombs became increasingly difficult to construct due to overcrowding, Romans sought more innovative solutions. One such solution was the development of columbaria, which provided multiple tomb slots. Upon payment to a subscription association, these slots were reserved for burial. However, this method was limited to cremation and didn't work for the burial practices of Christians and Jews.
For these groups, a new solution was needed: catacombs. These underground burial complexes utilized the natural properties of tuff, a soft volcanic rock that became hard after exposure to air. Romans used tuff to construct cheap bricks for monuments and walls, and where the natural resources for tuff were insufficient but still permitted diggings, Christians and Jews began constructing catacombs.
The Spread of Catacombs
Over time, the catacombs spread all around Rome. Some catacombs began from the basements of Christian-owned villas, such as the Catacombe di Priscilla via Salaria, or from old tombs used as stairwells to access the underground levels, like the Cimiterus Maius via Nomentana.
It is important to note that Roman authorities were aware of the catacombs, but the Roman law protected these underground tombs under the same protective measures as above-ground ones. Thus, historical depictions of Christians hiding in catacombs for safety are not accurate representations of reality.
Overall, the engineering prowess of the Romans was impressive, utilizing advanced techniques and the natural properties of materials to create complex underground systems that have stood the test of time.
h2Conclusion/h2
The construction of Romans' underground tunnels and catacombs exemplifies their remarkable engineering and innovation. Cloaca Maxima, aqueducts, and the development of catacombs showcase the advanced techniques and materials used. Despite misconceptions, the Romans' understanding of the law and geography allowed for the protection and preservation of these underground structures.