Halbtontonnengewölben

Halbtontonnengewölben, also known as half-barrel vaults or segmented barrel vaults, are a type of masonry vaulting construction. They are essentially a portion of a barrel vault, typically a semicircle or a segment thereof, that spans between two parallel walls or arches. Unlike a full barrel vault which forms a complete semi-cylindrical shape, a half-barrel vault covers only half of this space.

These vaults are often employed when the full height or width of a traditional barrel vault is not feasible or desired. They can be used to cover a rectangular space, providing a curved ceiling over a portion of the room. This design can be structurally advantageous, as it concentrates the thrust of the vault onto the supporting walls or piers, potentially requiring less substantial buttressing than a full barrel vault.

Historically, halbtontonnengewölben have been used in a variety of architectural contexts, including churches, civic buildings, and even industrial structures. Their construction involves setting voussoirs, or wedge-shaped stones or bricks, in concentric rings, with the outward thrust of the vault being resisted by the supporting walls. The visual effect is one of a segmented or groined ceiling, depending on how multiple half-barrel vaults are combined. While less common than full barrel vaults or groin vaults in monumental architecture, they offer a practical and aesthetically distinct solution for covering spaces.