In 2019, the Notre-Dame Cathedral in Paris was devastated by a huge fire – the flames severely damaged the iconic medieval structure. Later, when the restorers took up the reconstruction work, unique structures of this structure were discovered, which scientists had not seen before in the architecture of that era.
A few months after the fire, researchers discovered that the stones used to build this Gothic-style church were held together by metal construction staples. It turns out that such a construction technique was not recorded in any construction document of the time and it is a unique technical solution of the time, according to a recent study published in the journal PLOS One.
The Paris Notre Dame Cathedral was built in several stages – construction began at the beginning of the 12th century, but the construction lasted another 300 years.
“This is the first time we have seen a structure of this kind. This shows that the builders in their time tried to experiment with new forms of construction engineering”, – for the portal livescience.com said the author of the study, prof. Maxime L’Héritier of the History Department of the University of Paris 8.
L’Héritier and his team examined 12 metal construction staples, about 50 cm long. These staples are carved into the entire stone structure of the church and act as a skeleton that serves as a reinforcing structure, according to the study published in the journal Sapiens.
These building staples strengthened the stone structures of the cathedral. One example is the giant arch in the nave of the church, located between two identical 69-meter-high towers. Without these metal staples, such an architectural solution in the middle of the 12th century (around 1160) would have been impossible.
“We researched other Gothic churches of the period and none of them found metal staples to hold the structure together. It is believed that it was precisely such metal fasteners that allowed the engineers of the time to build structures of such height,” said M. L’Héritier
The scientists also carried out a radiocarbon study, during which they found that the metal building staples were forged at the same time as the brick walls of the church – that is, around 1160.
Ms. L’Héritier emphasized that further research will be conducted to determine the origin of the metal construction staples.
“We are trying to find out if these staples are locally made or brought from further afield.” It can also be seen that depending on the time of construction, the origin of the iron ore used to forge the staples also differed. We know that the then bishop of the cathedral died at the end of the 12th century, so it is likely that when the bishop changed, the place of origin of the building materials could also change,” said M. L’Héritier.
Based on the news agency APthe reconstruction of the Notre Dame Cathedral in Paris should be completed in December 2024.