It is not yet spring in the forest of Bercé (Sarthe) but it is already here that that of Notre-Dame is being prepared. In this peaceful forest, far from the hustle and bustle of the Île de la Cité, the restoration of the framework began with the selection of the first trees which will enable the spire of the cathedral destroyed by fire to be rebuilt.
Friday March 5, the Minister of Culture Roselyne Bachelot and the Minister of Agriculture Julien Denormandie, accompanied by General Jean-Louis Georgelin, President of the public establishment responsible for the conservation and restoration of Notre-Dame Cathedral de Paris, and by the chief architects of historical monuments Philippe Villeneuve and Rémi Fromont, came to celebrate this stage, by “marking” the first of the eight oaks destined for an exceptional second life. The forest stamp, identifying the trees to be cut, was affixed to a 200-year-old oak tree, over 20 meters high.
This step was preceded by careful selection. “We walked through the plot with the architects to find the oaks that will form the stool (base) on which the spire rests, explains Claire Quiñones, forestry engineer at the National Forestry Office. Trees over a meter in diameter were needed to form pieces 20 meters long, with the constraint that they should be slightly bent to match the shape of the vaults ”. A drone was used to study the tops of “candidate” trees. 3D models made it possible to ensure that the necessary parts could well be cut from the trunks.
Labeled an exceptional forest in 2017, the forest of Bercé is one of the most beautiful forests in France, heir to the royal domain and the forest reserves created by Colbert in 1669. Here, fourteen generations of foresters have already succeeded in sustaining a “cathedral forest” which has never so aptly borne its name. It is in an area undergoing renewal that the oaks intended for Notre-Dame will be “harvested” – a term used in the profession.
« We are here in a phase of generational change, continues Claire Quiñones. We cut down the 200-year-old trees, and plenty of young shoots are already there to remake a 200-year forest cycle. “
Trees shaped by man
Contrary to popular belief, the trees that will continue their life on the heights of Notre-Dame have been shaped by man. “We force them to grow tight and we lighten them regularly, every 10 to 15 years, so that they seek the light upwards”, explains Brice Gaumont, forestry technician. This know-how gives them a unique shape: straight trunk, absence of side branches and reduced crown (leafy part of the tree).
Cutting is part of forest management. “Here we have more than 100,000 trees over 160 years old, and we cut between 200 and 1,000 each year ”, evaluates the forester.
In Jarny, the props of Notre-Dame de Paris are ready
For the reconstruction of the frames of the spire, the transept and the adjacent spans, a thousand oaks will be necessary. They were chosen throughout France and will be cut by the end of March “Before their rise in sap”, specifies Arnaud Lemaire, architect and project manager within the public establishment. The timber will be sent to the sawmill towards the end of August and then dried for 12 to 18 months.s, “to be ready by the end of 2022”.
Planted by a great-grandfather
These oaks will come in equal parts from public forests (State and forest municipalities) and private. The day after the fire, the professional France Bois Forêt had indeed offered to offer wood, its processing and transport.
Owner of the Beffes forest (Cher) and president of the Forest Cooperatives, Bertrand Servois will thus donate five trees. A pride for this operator. “These are trees that my great-grandfather had planted in 1880 without knowing what they would be used for”, he specifies. Until this day when the long time of the forest meets that of heritage …
Securing the monument continues
* The installation of wooden hangers intended to support the vaults during the duration of the work has started. “We are in the process of mounting them in the choir and then we will progress in the transepts and the nave”, specifies Philippe Villeneuve, chief architect of historical monuments in charge of Notre-Dame.
* This operation should continue “Until the middle of summer”. The securing phase will then be completed and the peril order can be lifted.
* There will ultimately be no “large umbrella” of protection placed above Notre-Dame, as initially envisaged. “It was complex to set up and a bit risky, with too much wind resistance and too much weight, explains Philippe Villeneuve. We made the choice to keep the floors that were used by rope access technicians to access the vaults. They will serve as a roof and we will ensure the waterproofing with tarpaulins. “
* Minister Roselyne Bachelot announced on March 5 that the future framework will incorporate “ modern and very advanced fire safety devices with, in particular, a fire-rated partitioning of the attic ”. The National Heritage and Architecture Commission (CNPA) will be consulted on the framework restoration scenarios on March 25.