Linköping Cathedral is Sweden’s largest stone church, an impressive structure made of carved limestone that sits prominently on a hill in the center of the city. Its massive blocks are expertly crafted, showcasing exceptional stonemasonry through detailed decorations, keystones, and arches.
For generations, Borghamns Stenförädling has supplied stone and conducted restoration work on the cathedral. In 2021, they delivered a newly manufactured rose window, highlighting the successful combination of advanced digital technology with traditional craftsmanship. This new window replicates an original from the 14th century.
The completion of this window symbolizes the restoration efforts that earned the 2021 Stone Prize. Tim Ericsson led the project, which involved just over 300 hours of work.
— “It was like putting together a puzzle,” he remarked.
To create the new window, the original was scanned and reconstructed using a 3D program, incorporating its existing damage and misalignments that required correction.
The programming process was complex and time-consuming. The window has a diameter of 1.6 meters and is 13 centimeters thick.
We selected the quarry with great care because it’s essential to understand the characteristics of the stone. Different positions yield different colors and properties, according to Tim.
The new window was manufactured in two halves for easier handling and to minimize the risk of damage. Milling was performed using a five-axis CNC milling machine, and for areas inaccessible to the machine’s round cutters, manual techniques were employed.
“Details and sharp contours are hand-carved, and all surfaces were also hand-carved to match the original,” Tim explains. The pieces were then bonded using a stone adhesive that was colored to be inconspicuous.
“This task isn’t suited for just anyone. The choice of material is crucial. It’s the small parts that help the stone hold together. We can’t afford any unexpected problems,” Tim emphasizes.
Through this window project, he has gained significant knowledge that will be beneficial for future work.
“The project with the church is ongoing. It’s always exciting to learn,” he adds.
