Julius Caesar may be the most recognized name in Roman history, but it was his heir Augustus who ushered in Pax Romana (Roman Peace), a golden age of art and technology lasting from 27 BC to 180 AD. Roman engineering flourished, and Roman citizens enjoyed many of the luxuries we have today. Aqueducts channeled clean water to elaborate bathhouses, furnaces pumped hot air to heat tile floors, and a network of roads facilitated trade and travel across the vast empire. “I found a Rome of bricks,” said Augustus on his deathbed. “I leave to you one of marble.”
The works of Roman engineers are truly marvelous, and it’s because of their ambition and ingenuity that so many Roman monuments have outlasted the empire that built them: wonders like the Colosseum, Pantheon, and Hadrian’s Wall. These sights capture the imaginations of people the world over but do little to convey the engineering principles behind their design and construction. Here’s our take on the engineering marvels of ancient Rome.
The city of ancient Rome was founded on the banks of the Tiber River. Unfortunately, the waters of the Tiber were not potable and became less so after the construction of the Cloaca Maxima, a sprawling sewer system that began as an open-air, fresh-water channel in the sixth century BC. The first major work of hydraulic engineering in ancient Rome, the Cloaca Maxima improved public health by directing human waste to the Tiber and was so impressive that German historian Barthold Georg Niebuhr proclaimed it “equals the pyramids in extent and massiveness, [and] far surpasses them in the difficulty of its execution.”
Built to Last
Ancient Romans knew how to pick their building materials. “Roman concrete is … considerably weaker than modern concretes,” says mechanical engineer Renato Perucchio. “It’s approximately ten times weaker.” Yet the Colosseum, Pantheon, and Pont du Gard have endured nearly two millennia of corrosion. The longevity of ancient Roman concrete can be attributed to its formula, particularly its inclusion of volcanic ash. During Augustus’ reign, builders experimented with different mortar recipes, eventually settling on a blend of limestone and volcanic sand from the Pozzolane Rosse, an ash flow from the Alban Hills volcano. Roman concrete may not be as strong as its modern counterpart, but its unique properties are why so many of Rome’s ancient monuments have stood the test of time.
Needing a clean water source, the city relied on what would become a staple of Roman engineering: the aqueduct. Rome wasn’t the first society to use aqueducts—irrigation was present in Egypt and other Middle Eastern countries hundreds of years earlier—but Romans did improve upon the design. Aqueduct systems consisted of a series of underground pipes and above-ground bridges leading from lakes and streams in the surrounding countryside to Rome. Gravity was all that was needed to convey water across miles of fields to the city’s fountains, latrines, and bathhouses, sometimes from locations 60 miles away. Bridges consisting of stone arches made up a small portion of the aqueduct systems found throughout the Roman empire, and some, like the Aqua Virgo, are still in use today.
The arches featured in the Aqua Virgo are more than just aesthetic. Their design is key to preventing many of the monuments of ancient Rome from collapsing under their immense weight. Arches are able to span large spaces with limited materials thanks to Newtonian physics. Voussoirs, or wedge-shaped stones, squeeze together and push back against vertical loads, creating an outward, diagonal force (thrust) that can be countered with buttresses. In the design of aqueducts and bridges, Roman engineers ingeniously placed segmental arches in rows where they could support one another and transfer forces to stone or concrete abutments.
The Secret Behind Roman Architecture
What is the secret to ancient Rome’s architectural prowess? Certainly not their use of simple mathematics, which paled in comparison to the Pythagorean theorem and other contributions made by ancient Greek mathematicians. (Roman numerals aren’t exactly ideal for performing complex calculations.) Rather, they relied on practical rules of thumb. For example, without a clear understanding of the physics involved, they somehow knew to favor compression over tension forces when building concrete arches and domes.
Ancient Rome’s famous domed structures employ the same design principles found in aqueducts: Vertical loads are supported by lower parts of the structure pushing back. To compensate for tension forces threatening to flatten the dome, engineers behind the Pantheon used lighter concrete toward the top of the dome and added stepped rings to its outside for reinforcement. They also incorporated blind arches in the Pantheon’s 20-foot-thick walls. At a time when even the wealthiest Romans lit candles and oil lamps to brighten their homes, the oculus at the center of the Pantheon’s roof illuminated its spacious interior with natural sunlight. When Italian sculptor Michelangelo stepped onto the Pantheon’s marble floor, he said it was the design of angels, not men.
Make History as a Mechanical Engineer
Engineers have far more tools at their disposal today than they did in ancient Rome, relying on computer-generated models and simulations rather than trial and error. Yet for all their convenience, modern technologies and design processes are only as good as the professional using them, who must have in-depth knowledge and a robust skill set. That’s why The University of Texas at Austin offers two 100% online programs for aspiring engineering leaders and innovators:
- Executive Master of Science in Mechanical Engineering
- Mechanical Engineering Controls Graduate Certificate
At UT Austin, you’ll find online engineering programs designed with the same care that went into making the monuments of ancient Rome. Our programs explore emerging trends and technologies that’ll prove invaluable in your career. Courses are entirely online and asynchronous, so you can pursue a graduate credential while balancing professional and personal responsibilities. And our esteemed faculty will guide you every step of the way to encourage your mastery of mechanical engineering topics. Upon graduating, you’ll be awarded a graduate credential, and you’ll have earned knowledge and skills highly sought after in your industry.
Do as the Romans do. Apply to one of our 100% online mechanical engineering programs to take the first step in becoming an engineering leader and innovator.