Notre-Dame de Paris: the spire stool, central and crucial point of the reconstruction

This is a key stage in the restoration of Notre-Dame de Paris: the first stage of the identical restitution of the spire. It must be crossed on April 15, 2023, four years to the day after the fire which led to the spectacular fall and destruction of the structure designed by the architect Eugène Viollet-le-Duc.

A new and imposing base on which the entire structure will rest, a stool in solid oak wood built in Meurthe-et-Moselle, is transported by several exceptional convoys to Paris, in the heart of the Ile de la Cité, after a mock-up: last verification operation, outside a huge carpenters’ workshop, before its installation at the transept crossing, in the cathedral.

“The stool will allow the spire to be raised above Notre-Dame”

It is in Briey, near Metz, in this 7,000 m2 workshop, that four usually competing companies have now come together in a consortium to whom the work is awarded – Le Bras Frères (Meurthe-et-Moselle) agent, Asselin ( Deux-Sèvres), Cruard (Mayenne) and MDB Métiers du Bois (Calvados) – have been working hand in hand since last September to manufacture the entire frame of the spire.

More than a thousand oak trees from all over France and brought together in storage spaces over 10,000 m2 are gradually pruned to reconstitute the different elements, based on the technical and heritage guidelines of the project manager.

The stool consists of 110 parts with a very complex geometry and which come in particular from eight logs of more than one meter in diameter, selected in the spring of 2021 in the forest of Bercé in the Sarthe. Huge and decisive thanks to its wide impasto, it must indeed ensure the stability of the arrow and allow it to culminate at 96 metersas the chief architect of historical monuments, Rémi Fromont, explains:

“We have exceptional woods, both in terms of their quality and their size, their straightness… the spire stool is the foundation of the spire which rests on the masonry approximately 30 meters from the ground and which will enable the spire to be raised above the cathedral. It is a very massive set that is 14 meters on a side, 21 meters diagonally and 6 meters high.. The trial assembly is a big dress rehearsal to ensure that everything works as well as possible, at the time of lifting and final assembly on Notre-Dame.”

“The blank assembly is a real rehearsal for the companions”

With cranes and lifting gear to move all the parts of the stool, the assembly of the assembly of 80 tons is therefore a crucial step, confirms Aurélien Lefevre, the general manager of Cruard, company of the group in charge of the works of restitution of the frame of the arrow:

“This allows us to check everything we have been able to carve in the workshop. It’s a structure that is very technical, extremely complex. The very difficult cutting by hand requires a lot of precision and the blank assembly is very meticulous, very precise. We must have all the assemblies that flatten. There must be no play between the assemblies, because there is no question of recutting, when we are in the cathedral. It must absolutely stick, be kept to a minimum, because there will be a lot of load on this stool which bears its name well. It must be flawless and as solid as possible. It’s a real rehearsal compared to what we will have to do on the site, modifying our installation methodology a little if necessary. We are training our companions for what will happen there. It’s a great pride for all of us and we can’t wait now to be in the cathedral, to go and put the stool down.”

More than 40 companions are mobilized and all very proud to participate in the adventure. Gabin Sesta, from Le Bras Frères, a 33-year-old carpenter, is really happy to be on hand for the dry-fitting:

“We have just lifted the last diagonal of the trestle, which must be removed without damaging anything, without splitting the wood. It’s quite delicate and on the spot, we will be 30 meters away and there will be the scaffolding. It’s more than exciting. That’s all you dream of doing when you start in the frame, to touch such large pieces of wood and which especially go on Notre-Dame. Which is still quite iconic. And it will last for centuries, we hope!”

“The beginning of the visible revival of Notre-Dame”

This first stage in the restoration of the spire is also a sensitive stage for General Jean-Louis Georgelin, president of the public establishment responsible for the restoration of the cathedral:

“Remember! The whole world watched live as the spire collapsed. We could hear people crying, when we saw the needle fall, then the whole spire in the transept. This is what we call our critical path and it is the strongest symbol of reconstruction.”

The 66-meter-tall spire, like its 19th century model, will be restored identically for the duration of the operations. As in the years 1859 and 1860 under Viollet-le-Duc, its manufacture and installation will take a total of 18 months. The placement of the stool, at the top of the four large interior pillars of the crossing of the transept, really kicks off the most noticeable work of the restoration, for the chief architect of Notre-Dame, Philippe Villeneuve:

“The stool is the base that will support the arrow. But the arrow, it has already started there, since the first pieces of the needle leave at the foot of the pillars. So that’s the start of the arrow. I gave as objective that this element be, symbolically, set up for April 15, anniversary date of the fire, because it is the beginning of the visible rebirth of Notre-Dame. Finally seeing pieces of wood that have burned, seeing them come back, reborn from their ashes, is very moving and symbolically very very strong. Because we don’t see all the work that has been done. Half of the nave remains to be restored, but the transept arms and interior restoration are complete. The spire frame will be completed at the end of the year and I should normally put the rooster on top of the spire on December 8, 2023one year to the day before the reopening of the cathedral to worship and the public.”

The schedule is therefore for the moment respected for the reopening of Notre-Dame, on December 8, 2024. Three exceptional convoys are scheduled from the large workshop in Briey, in Meurthe-et-Moselle, to transport the 110 pieces that make up the base of the spire, on the restoration site of the cathedral. About fifteen assembly steps are planned on site, with the participation of 60 carpenters.

After the installation of the stool at 30 meters in height, above the diagonal arches and the stone oculus of the crossing of the transept, the scaffolding will continue its ascent, depending on the construction of the framework, until ‘to reach 100 meters in height. It will be possible very soon, starting this summer, to see the arrow rise in the sky of Paris.