Rib vaults are best described as which of the following?

• A. A simple barrel vault
• B. A groin vault formed by the intersection of arches
• C. A rib vault formed by a framework of diagonal arches
• D. A curved hallway

Answer: (C)

Rib vaults are defined by a skeletal framework of ribs—arched lines that rise and intersect, forming a grid-like skeleton that carries the weight of the vault while leaving more space with lighter infill panels between the ribs. This emphasis on the ribbed framework, usually with diagonal or crossing arches, is what sets rib vaults apart from other vault types. A simple barrel vault is just a continuous curved tunnel with no ribs, and a groin vault results from the intersection of two barrel vaults rather than from a ribbed skeleton. The idea of a curved hallway doesn’t capture the structural feature that defines rib vaults.