Notre-Dame de Paris is one of the most famous Gothic churches in the world, built between the 12th and 14th centuries in Paris, France.
During the construction process, the architects used many new techniques to create a building with a bold and unique architecture. One of the most important techniques was the use of iron to bond the stone blocks during the initial construction.
Notre Dame Cathedral in Paris during restoration after the fire. (Photo: Maxime L’Héritier)
A fire in 2019 destroyed Notre Dame, but also provided an unprecedented opportunity for researchers to understand the building’s architecture. Researcher Maxime L’Héritier at the University of Paris 8, and colleagues published their new findings in the journal PLOS ONE on March 15, 2023. At the time of construction in the mid-12th century, Notre Dame was the tallest building ever built with a height of 32 meters. Previous research has shown that this record was achieved by combining several architectural achievements. However, although iron reinforcement is very popular in recent churches and in the restoration of old buildings, experts still do not know the role of iron in the initial construction of the German church. Grandma.
The 2019 fire and subsequent reconstruction allowed L’Héritier and his associates access to a previously hidden part of the church, revealing clues to the use of iron in construction. The team collected material samples from 12 iron clamps used to attach stone blocks in various locations of the building, including the platform, nave and wall. They applied carbon isotope dating, microscopy, chemical and architectural analysis to better understand the pins.
The results of the analysis show that iron clamps were used at the earliest stage in the construction of Notre Dame in the 1160s, making it the first building to use iron clamps in its structure. Combined with other archaeological and historical insights into the period, the analysis provides information that enhances understanding of iron trading, bartering, and forging in the 12th and 13th centuries in Paris. For example, many clamps appear to have been forged by soldering two pieces of iron from different sources.
According to the researchers, a closer analysis of the Notre Dame specimen and a historical database of iron producers in the region is needed to confirm and expand the findings regarding the Paris iron market. the Middle Ages.