Breaking News! "Lean On Me" by Bill Withers was actually inspired by ancient Roman domes

 

I think that one of the coolest advancements in Roman building styles was the development of semicircular roofs such as domes and vaults. For the Romans to be able to create that type of shape, some of which would survive thousands of years, is truly mind boggling to me. Some domes didn’t even have concrete holding them together![1] Although this didn’t happen overnight, before Romans could build domes, they first had to learn how to make arches and vaults.[2] 

An example of the types of arches that made domes possible. 

Image credits: Alayna Krueger

One of the oldest surviving examples is at the Stabian Baths of Pompeii, this was a conical concrete dome, built at frigidarium, 6 meters in diameter and dates to 120 BCE.[3] Domes were constructed as a series of arches, arranged around a vertical axis through the crown and tied together by horizontal hoop forces.[4] The pantheon in one of the most impressive and in tact examples of this architecture. 

The domed roof of the Pantheon. 

Image credits: Alayna Krueger

It is also a great example of how the ancient architects overcame the problems caused by hoop tension. It has a hemispherical dome inside, the thickness of the upper part is a little over 1 metre, where hoop tension becomes an issue, the thickness increases in steps, this is because more material in the region of the hoop tension, lessens the tensile stress compared to a dome of uniform thickness.[5] 

Aerial view of the pantheon that demonstrates the increased thickness in the region of hoop tension. 

Image credits: Alamy stock photo

The pantheon is just one example of how the Romans were able to overcome structural difficulties when building domes and really goes to show their ability in perfecting their techniques. 

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[1] Usanmaz, Uygar  Ozan. “A GLIMPSE INTO THE ORIGINS OF ROMAN CONCRETE DOMES.” Akdeniz Üniversitesi Sosyal Bilimler Enstitüsü Dergisi, no. 11 (2022): 45.

[2] Usanmaz, 30.

[3] Usanmaz, 34.

[4] Cowan, Henry J. “Domes—Ancient and Modern.” Architectural Science Review 20, no. 2 (June 1977):  doi: 10.1080/00038628.1977.9697235. 183.

[5] Cowan, 183

Bibliography

 

Cowan, Henry J. “Domes—Ancient and Modern.” Architectural Science Review 20, no. 2 (June 1977): 181-198. doi: 10.1080/00038628.1977.9697235.

 

Usanmaz, Uygar  Ozan. “A GLIMPSE INTO THE ORIGINS OF ROMAN CONCRETE DOMES.” Akdeniz Üniversitesi Sosyal Bilimler Enstitüsü Dergisi, no. 11 (2022): 30–52.