Why were the scissor arches added to Wells Cathedral in England?

The scissor arches were added to Wells Cathedral to stabilize the tower’s supporting piers.

Wells Cathedral’s unusual crossing arches were a structural response to serious movement in the central tower. The tower had been heightened and topped with a spire between 1315 and 1322, increasing the load and stress carried by the piers beneath it. The piers began to show signs of sinking and instability.

Around 1338, master mason William Joy inserted low arches crossed by inverted arches, producing the distinctive scissor-like form. These arches brace the crossing piers as a connected unit and help distribute the tower’s forces through the cathedral’s structure. They are also called strainer arches or St Andrew’s Cross arches.

The arches are sometimes mistaken for decorative Gothic flourishes or for supports intended to make the tower taller. Their dramatic appearance is memorable, but their primary purpose was practical engineering. They allowed the cathedral to retain and support its central tower after the tower’s enlargement, making Wells an important example of medieval structural problem-solving.