How to Rebuild Notre-Dame Using 12th-Century Tools

In Washington, D.C., an innovative team of designers demonstrated how medieval techniques could be used to repair the Parisian landmark

A full-scale replica of Notre-Dame’s Truss
A full-scale replica of Notre-Dame’s Truss 6 in Washington, D.C. last summer. Shuran Huang

The roof of Notre-Dame de Paris was still burning in April 2019 when Rick and Laura Brown got a call from their daughter Rian, a documentary filmmaker and professor at Oberlin College. “This sounds like a project for you,” she said.

“Let us think on it,” Rick replied, which usually means yes.

Notre-Dame de Paris before and during a fire
Notre-Dame de Paris, before and during the April 2019 inferno that brought down the grand spire. Getty Images
The Browns are at the forefront of a field called experimental archaeology—recreating ancient objects using the tools and techniques of those eras. Their main goal is education—teaching their students at the Massachusetts College of Art and Design to recreate age-old monuments and more. “The object itself is loaded with information,” Rick says. “You don’t understand it until you reverse-engineer it and experience the process.”
Rick and Laura Brown sit for a portait
Rick and Laura Brown during a brief respite from overseeing the reconstruction. Courtesy of Rick and Laura Brown

The couple met while studying sculpture at the University of Georgia in the early 1970s. After graduating, they bounced around the country and academia, eventually settling in Boston. Fascinated by New England’s architectural history, they joined the Timber Framers Guild, a 1,400-member group devoted to the old-fashioned craft of building structures with beams and joints held together by wooden pegs.

In 1998, Grigg Mullen Jr., a civil engineer and retired professor at the Virginia Military Institute who has worked with the Browns since their earliest projects, put out a call for volunteers to recreate a full-sized medieval trebuchet, a kind of catapult and the period’s most fearsome weapon. The Browns took part in the workshop, and on the flight back to Boston, Rick sat next to PBS “Nova” producer Michael Barnes, who asked Rick if he thought he could recruit timber framers from the workshop to help assemble more weapons for a “Nova” program, “Secrets of Lost Empires.” The show culminated with participants raising two full-sized trebuchets next to a castle on the shores of Loch Ness in Scotland.

timber lays on the ground
Virginian timber used for the truss. Shuran Huang

Other historical questions followed: How did medieval craftsmen lift the enormous stones used to build castles? Working off old manuscripts and illustrations, the Browns collaborated with timber framers from the United States, the United Kingdom, Germany and the Czech Republic to build human-powered cranes consisting of timbers, ropes, pulleys and wooden hamster wheels big enough for a person to walk in. The Browns also helped build another crane to make repairs on the 14th-century Tocnik Castle outside Prague, which sits on a plateau too small for today’s mechanized cranes.

Two carpenters working on a wooden truss.
Mark Segro, left, one of the carpenters who helped recreate the truss, with a student. Shuran Huang

The Browns’ longest undertaking involved the Gwozdziec Synagogue, built by Polish Jews in the 1650s and destroyed by Nazis in the 1940s. Through their nonprofit organization, Handshouse Studio, the Browns assembled teams of carpenters, students and volunteers to build a replica of the synagogue’s timber-frame roof. On the underside, they recreated its painted ceiling—exuberantly decorated with Hebrew letters, animals and vibrant geometric designs—using paints they’d made, similar to those used by the original painters in the 17th century. Along the way, the Browns transported the ceiling panels to seven different cities in Poland, inviting Polish students to join the painting team. By the time the roof was finished in 2014, more than 300 students, carpenters and artists had taken part. The result was permanently installed at the POLIN Museum of the History of Polish Jews in Warsaw. “It’s more than recovering an object,” Barbara Kirshenblatt-Gimblett, program director of the Jewish Historical Institute of Poland, said of the project in a 2014 documentary. “It’s recovering a world.”

The burning of the Notre-Dame cathedral in April 2019 inspired the Browns and their students to launch a new, international educational project. After two-thirds of the cathedral’s roof and most of its spire were consumed by the flames, Carpenters Without Borders, a French group, held that the structure should be rebuilt using medieval methods, an argument the group eventually won. The Browns offered to help demonstrate the potential of experimental archaeology in this singular case—a gesture of goodwill and solidarity. In response, the French carpenters sent them the plans for Truss 6, a supporting structure that hung over the choir. Estimated to have been built in 1180, the truss was one of the oldest features of a cathedral that took nearly two centuries to build starting in 1163.

The School of Architecture and Planning at Catholic University in Washington, D.C. agreed to host the project as part of a summer course. In May 2021, Mez Welch, a member of the Timber Framers Guild, got permission from Virginia landowners to chop down some white oak trees and drag them out with horses. In late July and early August, several dozen timber framers and students gathered to fashion the truss.

The lawn next to the university’s basilica became a preindustrial work site. Workers stood lengthwise along the 40-foot-long tree trunks lying horizontal across wooden supports, and the team scored wedge-shaped perforations into the sides with a felling ax, a heavy-headed tool with a blade ideal for cutting cross grain into wood. Once they’d completed that job, the workers pivoted and chopped along the length of the trunk, chipping away the wood between the wedged openings to create a flat surface. For this task they used axes, some beveled on one side and flat on the other. Thus, a team of humans did the work of a sawmill, transforming a raw trunk into a rough-hewn wooden beam.

A carpenter works with a chisel
Mez Welch builds a wooden base that will hold the truss upright in museums. The team diverged momentarily from medieval tools, using a chainsaw for a minute or so to finish the base. Shuran Huang

Next, the volunteers used chisels, small axes and saws to create the joinery that would hold the notched timbers together—hollowed-out boxes called mortises, and tenons, the wooden plugs that would fit into those boxes. Some of the workers’ children pitched in, helping their parents use clamps and drawknives to shave the pieces to the correct dimension. The work site was quiet. There were no roaring engines, no screaming saws, no percussive cracks of air-powered nail guns; just the chuck-chuck of axes and the murmur of conversation.

On the tenth day, dozens of people stood alongside the beams and began to line up all the joints, following the crew chief’s instructions. The workers used muscle power, mallets, ropes and winches to pull the pieces together, then sealed the deal by banging wooden bolts called clavettes into place with mallets. It was as if they were assembling a three-dimensional jigsaw puzzle where each piece weighed hundreds of pounds and all the pieces had to fit together simultaneously.

works assemble a wooden truss
Handshouse Studio has displayed the truss in American museums, but the Browns’ highest ambition is one day to install it in Notre-Dame. Shuran Huang

Finally, the time came to hoist the finished triangular truss upright. The crew assembled two 24-foot-tall timber A-frames and fastened them to the base of the triangle. The truss weighed four tons and would stand 36 feet tall once the team hoisted it gently to the sky; hoisting it too forcefully would cause it to topple forward. Another danger: Attaching the hoist ropes to the wrong point on the triangle could cause the structure to buckle and the pieces that held it together to pop apart. “It’s basically a sophomore-level course in engineering,” Mullen said.

Slowly, the huge triangle began to rise. After ten minutes, it stood upright, held in place by heavy ropes fastened to the ground on each side. The youngest team member, 20-year-old Nevan Carling, shinnied up the truss and tied a piece of evergreen, called a “wetting bush,” to the top—a tradition thought to have originated in pre-Christian Scandinavia that gives thanks to the forest for providing the trees.

When Carpenters Without Borders received the photos, François Calame, the group’s founder, responded: “Formidable!” He called the truss “an extraordinary gesture for us in France in the grand tradition of friendship between our countries.”

Some participants found themselves reflecting on another connection—between the human ingenuity that gave rise to medieval cathedrals and the religious awe that inspired them. While the truss was still flat on the ground, Cardinal Wilton Gregory, the archbishop of Washington, D.C., walked onto the work site, donned a hard hat and said a Hail Mary, invoking the saint for whom the French cathedral had been named. Then he joined the crew on the hoisting rope and pulled.

Two days later, the crew disassembled the truss and erected it in the lobby of the National Building Museum in Washington, where it wowed visitors for nearly two months. It spent March 2021 at the Millennium Gate Museum in Atlanta. It’s too early to say if the truss will ever travel to Paris as part of the reconstruction. But the Browns hold out hope. “Some of us have compared this to when France gave America the Statue of Liberty,” says Rick. “And this would be a gift back to the French.”

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This article is a selection from the April/May issue of Smithsonian magazine