It is not often that one can draw a clear line from the forest to the construction site. When it happens, it demonstrates the importance of trees and the timber industry, not just from an economic or engineering perspective but also from the lens of culture.
— Paul Iarocci
In April 2019 the famous Paris cathedral, Notre-Dame, suffered a fire that severely damaged the spire and roof of the building. The architectural marvel was first constructed in the twelfth century on the site of an ancient Roman temple. More or less completed by the mid-thirteenth century, the cathedral was the subject of additions and embellishments for one hundred more years thereafter. It survived the French Revolution and underwent a major restoration in the nineteenth century in the decades after the publication of the Hunchback of Notre-Dame in 1831. It even survived the aerial bombing campaigns of WWII relatively unscathed.
The Notre-Dame cathedral in Paris, France.
Although the walls are mainly constructed with stone, the roof structure and spire are made from wood. Over the centuries, the roof timbers had become dry with age. The fire that began in the attic tore through the upper structure, requiring the herculean efforts of 400 firefighters battling flames, smoke and the boiling lead that had formed the sheathing. Firefighting crews had to be wary of applying water to the exterior for fear of cracking the stonework, so incredibly, much of the firefighting effort took place inside the structure.
Notre-Dame is a building with an annual maintenance budget in the millions. Rebuilding costs are expected to run into hundreds of millions and perhaps billions of dollars. Even with computer-generated 3D modelling and the use of modern building materials, the reconstruction effort could stretch into decades.
Christophe (left) and Denis standing in front of the 602 skidder.
The original beams that supported the roof were milled from massive individual oak trees. Decision makers expressed early on that portions of the restoration would be completed using traditional materials. So while titanium may replace lead, the French government committed to sourcing timber from the same forests throughout France where the original 1,300 trees were hewed nearly a millennium ago.
SAS BERCE FOREST is a small family company owned by Denis Legeay. He works alongside his son Florent and one employee, Christophe Moreau performing mechanized felling of softwoods and motor-manual harvesting of high-quality hardwoods. SAS BERCE FOREST operates one Tigercat-made TCI* 602 grapple skidder, a second skidder, a harvester head equipped excavator, and a twelve-tonne forwarder.
Kid glove treatment. The logs were loaded with two cranes onto specially configured trailers.
The company, based in Pruillé l’Éguillé, near Le Mans, was commissioned to harvest eight oak trees from the Bercé Forest. This 5 400 ha (13,300 acres) tract has been a working forest for many centuries and is internationally prized for its high quality oaks that are used to make barrels for the wine industry. Ironically, Denis has faced some business challenges also related to fire. Over the past two years, the massive California wildfires have polluted many Napa and Sonoma vineyards with smoke, damaged vines, or destroyed infrastructure entirely. In addition, COVID lockdowns negatively affected wine production and sales.
The French National Forestry Office, which owns the Bercé Forest, is responsible for tree harvesting in France. The office collaborated with carpenters to select the specific trees to be harvested based on length and shape.
“I was involved in the tree harvesting project for the construction of Notre-Dame, with long-standing relations with the French National Forestry Office and also the proximity of the mountain range that makes up the Bercé National Forest,” says Denis. “We participated in the harvesting of the first eight trees as well as loading the logs onto the trucks in a special convoy. Other oaks were harvested from other areas, with local loggers.”
The 300-year-old trees were, on average, 20 m (65 ft) in height, with an average volume of 15 cubic metres (approximately 15 tons). The harvesting process followed French custom. First, an arborist climbed the tree and manually removed all of the branches. Denis then used both of his skidders in tandem to lift each tree entirely off of the ground when transporting it to the loading area to prevent damage. This is very important as each tree was carefully selected for its particular shape. The timber was skidded to strategic points in the Bercé Forest to facilitate the loading, accomplished with two lifting cranes. The trees were loaded onto transport trucks specially adapted to the long lengths and delivered to a specialty sawmill that could accommodate the long lengths.
*Registered mark is owned by Tigercat Industries Inc., used under licence.
Harvesting for Wine
France’s beautiful hardwood forests contain many different oak species. White oak with its fine grain and aromatic properties is considered to be one of the best species for the production of wine barrels. Oak barrels are just porous enough to allow for some evaporation and oxygenation, but not so much as to spoil the wine as it ages.
Florent Salladin is an equipment salesperson for Clohse Group, the Belgium-based TCI dealer for France. He explains the typical process for harvesting oak trees for the wine barrel industry. “Someone climbs the trees to remove the branches.” This prevents the wood fibre from bursting and thus damaging the trunk when the tree is felled. “This is not so rare in France, especially in this area where you find really precious wood,” says Florent.
“Standing oaks can be sold for more than 1,000 euros per cubic metre. This is really expensive.” The logs are then sawn into strips or staves, using a special technique to maintain air permeability. After many months of air drying, the staves are heated, bent and assembled into barrels.