The Notre-Dame de Paris construction site
The day after the fire that struck the cathedral in April 2019, the Ministry and the National Center for Scientific Research (CNRS) have set up a vast restoration and scientific research project bringing together researchers and laboratories from all over France and organized in thematic working groups.
The cathedral on fire, April 2019, by Rémi Fromont, Ministry of Culture.
The opening of a scientific project
Following the fire that struck the cathedral, many researchers quickly showed their willingness to put their knowledge and skills at the service of the building, its works of art and the restoration site.
To accompany this momentum and organize the vast research activity that was expected, the Ministry of Culture approached the National Centre for Scientific Research (CNRS) to coordinate a scientific project that is the occasion for new discoveries in parallel with the restoration project.
This vast scientific project involves about fifty research teams and laboratories spread across France and brings together a total of 175 researchers. It brings useful information to the restoration site and renews knowledge about the building, its history, its environment, and, more broadly, about cathedrals and heritage.
The results of this work will enrich an innovative «monumental» information system, a veritable virtual double of the cathedral that will bring together and share all the knowledge produced on the monument.
The information system designed as part of the scientific project will gradually integrate the data produced by the various actors: both the actors of the scientific project (CNRS-Ministry of Culture) involved in the production of knowledge on the current state and previous states of the cathedral (historians, archaeologists, architects, engineers, physicists, chemists, etc.), as the actors involved in the restoration of the cathedral (Public institution in charge of the conservation and restoration of the Notre-Dame-de-Paris Cathedral as a builder, the owners, curators, restorers, etc.).
Thematic working groups
The scientific project CNRS/Ministry of Culture is organized in 8 thematic working groups whose leaders are met every two months by the coordinators to take stock of the research projects, their funding, their progress, their promotion through conferences, publications or online contributions.
They are made up of researchers from the National Centre for Scientific Research, the Ministry of Culture, the University but also bring together foreign specialists.
They bring together scientists from many disciplines: archaeologists, historians, art historians, anthropologists, physicists, chemists, engineers, computer scientists... who put their science at the service of Notre-Dame and heritage.
The eight working groups
The wood and the frame
The structure of Notre-Dame, the main victim of the fire, was often compared to a «forest» because of the large number of beams and their density.
This “forest” of Notre-Dame is a very important milestone in the history of structural design. Some of its unique structural features are considered to be the most sophisticated of their time.
Tracing its history and analysing its remains is a way of restoring part of this heritage to the public.
The acoustics
The researchers of the Acoustics working group are studying Notre-Dame with the aim of finding acoustics as close as possible to those that could host the singing of organs and masters and choirs.
Unlike stone, wood and glass, which are solid entities, acoustics remain impalpable. Nor can this acoustics alone account for the way in which the cathedral “sounded”. Researchers should therefore also study the sonic atmospheres that inhabited it, such as urban (outdoor) sounds, indoor sounds (movements, small and large religious ceremonies), concerts, etc.
The metal
This working group of the scientific site sheds new light on the use of iron and lead in the building and invites us to question the evolution of practices related to these metals over the centuries.
The glass
Notre-Dame-de-Paris Cathedral is lit by more than 120 stained glass windows dating from the 13th to the 20th century. During the fire, the vault was able to fulfil its role as a shield by insulating more than 3000m2 of glazed surfaces and the firefighters managed to control the action of the water to preserve the globality of the stained glass windows.
A transdisciplinary team brings its skills to the restoration project. She also took this opportunity to study and enhance stained glass windows and especially those of the 19th century, less known, but representing an important ensemble made under the authority of Eugene Viollet-le-Duc.
Stone and mortar, monumental decoration
The fire not only destroyed the structure of Notre-Dame but also damaged its stone structures (vaults, walls, columns). The action of the heat or the water poured out to extinguish the fire has indeed altered the solidity of the vaults, the condition of the masonries… which must therefore be the subject of technical diagnostics.
This is why a working group of some 30 stone specialists from different scientific fields was set up to work on these issues.
This research will also provide a unique opportunity to learn more about the construction process of a large Gothic cathedral.
The structures
This working group is interested in the structural evaluation of the elements that make up the structure of the cathedral (masonry structure, timber frame, belfry, etc.). It also analyses the actions that can be exercised on the latter, by fire or wind.
The digital
The group’s ambition is to build a “digital ecosystem” of the cathedral. This innovative monumental information system is designed to accompany the scientific study and restoration of the cathedral as the restoration project progresses.
All the knowledge produced at the restoration site and the scientific site can be aggregated and made accessible to different types of users.
These areas of reflection intersect several problems posed by the restoration work, such as the confrontation of the different temporal states, the analysis of the health status of the cathedral, or the restitution of lost forms.
Emotions and mobilizations
The strong reactions and mobilizations provoked by the fire show that Notre-Dame is not only made up of stones, wood or stained glass. As much as its towers or sculptures, it is also made up of collective representations and imaginations that make it exist in the eyes of the world.
To study these aspects of fire and its consequences, anthropologists and sociologists look at the bedside of the cathedral and follow the steps of its restoration within the Emotions/Mobilizations working group.
The crowd silently watches the fire from the Pont de la Tournelle by Godefroy Paris, Creative Commons.
Documenting Notre-Dame: collecting archives and photographs to make them available for the restoration project
Before any intervention on a historical monument, an important documentary step is required. The objective is to establish a diagnosis and a precise project so that the conservation and restoration are carried out in the rules of art and respect for the original work.
The databases of the Ministry of Culture (Mérimée, Palissy and Mémoire) have been enriched and illustrated by the Médiathèque de l'architecture et du patrimoine in order to give access to all available photographic documentation, records of movable objects and inventories of the archives of the restoration of Notre-Dame Cathedral.
At the same time, a census of the available archives was also carried out by the National Archives, which have the pre-revolutionary collections and those of the Religious Administration (Ministry of the Interior) during the 19th century. A joint dossier on these resources has been produced on the France Archives portal.