What is "barrel vault"

Vault \Vault\ (v[add]lt; see Note, below), n. [OE. voute, OF. voute, volte, F. vo[^u]te, LL. volta, for voluta, volutio, fr. L. volvere, volutum, to roll, to turn about. See Voluble, and cf. Vault a leap, Volt a turn, Volute.]

1. (Arch.) An arched structure of masonry, forming a ceiling or canopy.

   The long-drawn aisle and fretted vault.
   --Gray.

2. An arched apartment; especially, a subterranean room, use for storing articles, for a prison, for interment, or the like; a cell; a cellar. ``Charnel vaults.''
   --Milton.

   The silent vaults of death.
   --Sandys.

   To banish rats that haunt our vault.
   --Swift.

3. The canopy of heaven; the sky.

   That heaven's vault should crack.
   --Shak.

4. [F. volte, It. volta, originally, a turn, and the same word as volta an arch. See the Etymology above.] A leap or bound. Specifically:

   1. (Man.) The bound or leap of a horse; a curvet.

   2. A leap by aid of the hands, or of a pole, springboard, or the like.

      Note: The l in this word was formerly often suppressed in pronunciation.

      Barrel vault, Cradle vault, Cylindrical vault, or Wagon vault (Arch.), a kind of vault having two parallel abutments, and the same section or profile at all points. It may be rampant, as over a staircase (see Rampant vault, under Rampant), or curved in plan, as around the apse of a church.

      Coved vault. (Arch.) See under 1st Cove, v. t.

      Groined vault (Arch.), a vault having groins, that is, one in which different cylindrical surfaces intersect one another, as distinguished from a barrel, or wagon, vault.

      Rampant vault. (Arch.) See under Rampant.

      Ribbed vault (Arch.), a vault differing from others in having solid ribs which bear the weight of the vaulted surface. True Gothic vaults are of this character.

      Vault light, a partly glazed plate inserted in a pavement or ceiling to admit light to a vault below.

Barrel \Bar"rel\ (b[a^]r"r[e^]l), n.[OE. barel, F. baril, prob. fr. barre bar. Cf. Barricade.]

1. A round vessel or cask, of greater length than breadth, and bulging in the middle, made of staves bound with hoops, and having flat ends or heads; as, a cracker barrel. Sometimes applied to a similar cylindrical container made of metal, usually called a drum.

2. The quantity which constitutes a full barrel. This varies for different articles and also in different places for the same article, being regulated by custom or by law. A barrel of wine is 311/2 gallons; a barrel of flour is 196 pounds.

3. A solid drum, or a hollow cylinder or case; as, the barrel of a windlass; the barrel of a watch, within which the spring is coiled.

4. A metallic tube, as of a gun, from which a projectile is discharged.
   --Knight.

5. A jar. [Obs.]
   --1 Kings xvii. 12.

6. (Zo["o]l.) The hollow basal part of a feather.

   Barrel bulk (Com.), a measure equal to five cubic feet, used in estimating capacity, as of a vessel for freight.

   Barrel drain (Arch.), a drain in the form of a cylindrical tube.

   Barrel of a boiler, the cylindrical part of a boiler, containing the flues.

   Barrel of the ear (Anat.), the tympanum, or tympanic cavity.

   Barrel organ, an instrument for producing music by the action of a revolving cylinder.

   Barrel vault. See under Vault.

n. 1 (context architecture English) A simple roof having a curved, often semicircular cross section; used to span large distances in railway stations, churches, etc. Usually supported on columns. 2 (context roofing English) A building profile featuring a rounded profile to the roof on the short axis, but with no angle change on a cut along the long axis.

n. the simplest form of vault; a single continuous arch

A barrel vault, also known as a tunnel vault or a wagon vault, is an architectural element formed by the extrusion of a single curve (or pair of curves, in the case of a pointed barrel vault) along a given distance. The curves are typically circular in shape, lending a semi-cylindrical appearance to the total design. The barrel vault is the simplest form of a vault: effectively a series of arches placed side by side, i.e., one after another. It is a form of barrel roof.

As with all arch-based constructions, there is an outward thrust generated against the walls underneath a barrel vault. There are several mechanisms for absorbing this thrust. One is, of course, to make the walls exceedingly thick and strong - this is a primitive and sometimes unacceptable method. A more elegant method is to build two or more vaults parallel to each other; the forces of their outward thrusts will thus negate each other. This method was most often used in construction of churches, where several vaulted naves ran parallel down the length of the building. However, the outer walls of the outermost vault would still have to be quite strong or reinforced by buttressing. The third and most elegant mechanism to resist the lateral thrust was to create an intersection of two barrel vaults at right angles, thus forming a groin vault.

Barrel vaults are known from Ancient Egypt, and were used extensively in Roman architecture. They were also used to replace the Cloaca Maxima with a system of underground sewers. Early barrel vault designs occur in northern Europe, Turkey, Morocco and other regions. In medieval Europe the barrel vault was an important element of stone construction in monasteries, castles, tower houses and other structures. This form of design is observed in cellars, crypts, long hallways, cloisters and even great halls.