An ogive is a diagonally running rib in a vault, and the defining feature of the Gothic rib vault. The two ogives of a vault bay cross at the centre, where they meet in the boss or keystone. Together they form the loadbearing framework between which the vault webs are built.
Why the ogive matters
The ogive made Gothic architecture possible. Because the ribs take the forces and direct them to the corner points, the vault surfaces themselves carry almost nothing. That has three consequences:
- A lighter vault — the webs can be built thin
- Point loads instead of line loads — forces land on four points rather than along the whole wall, so the wall can be opened up with large windows
- A simpler build sequence — the ribs are built first on timber centring, then serve as the support for building the webs between them
Material and form
Ogives are usually of natural stone, in profiled blocks cut to size in advance. Simpler buildings also use brick ribs, and timber imitation vaults reproduce the ribs in wood. The moulding profile of the ogive — hollow, roll, pear-shaped or sharply arrised — is a useful aid in dating a building.
Ogive and pointed arch
The French phrase arc en ogive means pointed arch, which is why in older texts “ogive” is sometimes used for the pointed arch shape itself. It should also not be confused with the ogee, an S-shaped moulding profile: despite the similar word origin they are entirely different things.
Spotting it
Stand under a vault in a church or cellar and look up: do projecting bands run diagonally from corner to corner and meet in a carved stone at the centre? Then you are looking at ogives and a boss.
Related terms
- Rib vault
- Vault rib
- Keystone
- Vault
- Pointed arch
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