The ingenious answer was proposed by an art-engineering firm called SMACH. The company’s experts realized that, if the tapestry could not be rotated and stored, perhaps it could be stored and then rotated. They designed an object that resembles a huge, many-hinged ruler: a zigzag support that folds up, like a Japanese screen, into a neat cuboid. (They called this object le paravent, the French word for folding screen.) The museum could clip the tapestry to a rail, then feed it into the paravent inch by inch; when the whole thing was transferred, the huge zigzag could be folded up—with the tapestry secured between layers of padding—then turned on its side. When the extraction took place, last September, ninety people wearing blue latex gloves lined up behind the tapestry. A museum employee called out instructions—un, deux, tac tac, stop—and, on the third beat, everyone moved the tapestry another inch along the rail. The entire process took seven hours.
During the design phase for the paravent, SMACH believed that their object was going to travel only around three hundred metres, to a storage space in Bayeux. They were shocked to learn, halfway through, that it would be travelling three hundred miles, to London. “The mood was not great, I have to say,” SMACH’s co-founder Cécilia Gauvin told me. “We were all very scared about the outcome. But, you know, it came from above, so we had to do it.”
Gauvin asked a Dutch art-shipping firm, Hizkia, to think about ways to transport the tapestry. When the firm’s founder, Hizkia van Kralingen, drove down to Bayeux, he often found a huge group of people waiting for him. “The French, the English, the politics, the translators, the representatives from Macron—those meetings had thirty people in them,” he said. Hizkia’s plan was to build a huge crate around the folded paravent, then enclose that crate in a large aluminum frame. The big uncertainty of the operation involved vibrations. The loan specified a precise condition: the tapestry could be subjected to tremors no larger than two millimetres per second.
Van Kralingen asked a longtime collaborator, a German vibration-technology scientist named Kerstin Kracht, to join the project. “Vibration scientists, we’re the firemen,” Kracht told me, laughing. “It’s always the same. When a painting vibrates too much, when a car vibrates too much: ‘Kerstin, can you come?’ ” Since all of the objects in a system influence vibrational behavior, Kracht likes to study them first in isolation and then in combination. “It is a puzzle of subsystems,” she told me. “We have the subsystem of the truck, the subsystem of the inner crate, the subsystem of the wire-rope isolators, the subsystem of the outer crate, the subsystem of the paravent and of the object itself.” In this case, the paravent proved especially meddlesome. When a dry run took place in February, it became undeniable that the device was actually amplifying the tapestry’s vibration, which far exceeded the limit.
Most of the project team members were devastated. But Kracht was simply irritated. “This value drives me crazy,” she said. It wasn’t wrong, just incomplete. “Millimetres per second is a speed, and it’s an amplitude,” Kracht explained. That is, the metric tells you both how far an object moves and the time it takes to travel that distance. “The frequency—how often per second you change direction—says much more than amplitude,” Kracht said. While the tapestry’s amplitude surpassed the metric limit, the metric itself was misleading, and the work could travel safely with no further changes.
That left the bureaucratic challenge of communicating this fact to the relevant stakeholders. In a series of video calls with different groups, Kracht explained it in terms of a baby rocking in a cradle. Would it be better if it moved in short jerks, or in long, steady swings? “I don’t think all the people understood this, or, let’s say, wanted to understand it,” Kracht said. But, ultimately, the group was persuaded. When the tapestry finally travelled from Bayeux to London, it experienced fewer vibrations than many objects do from the ordinary footfall of a busy museum.