THE FLYING BUTTRESS ( Gothic "Spooky" Architecture)
Ribs act to concentrate the entire weight and thrust at the corners of the bays. The reduced, more concentrated load permits more slender piers and thus larger windows in the nave walls, provided there is sufficient buttressing of the lateral thrust. Since the thrust is gathered and localized at small areas, a counterthrust is needed only at those areas and not, as before, over a great extent. Even if the rib vault springs from a high point-it is necessary only to meet the lateral thrust that emerges from that point and to counteract wind pressures acting on the external surfaces. This is achieved with buttressing, effected by powerful external arches swung above the side aisles and the ambulatory. These arches rise from the colassal freestanding piers, which absorb the thrust in their immovable interia and channel the disruptive forces safely to the ground. This aptly named system of flying buttresses shifts the required butressing mass from the nave wall, where it would limit fenestration and require cumbersome supports below, to a location outside the aisle (and ambulatory) wall, where towering piers can be erected without much affecting the interior of the nave or choir.
TERMS:
NAVE: The central, longitudinal space of a basilican church, separated from the aisles or form side chapels, and extending from the main entrance to the transept or apse.
TRANSEPT: In a basilican church, the arm that crosses the nave at right angles, usually separating it from the apse; twin transept arms may also project from the nave without interrupting it.
FLYING BUTTRESS: in a church, a buttress in the form of an arch, or set of arches, that caries the thrust of a nave vault over the side aisle roofs down to a massive external pier.
APSE: a semicircular or polygonal reecess at the end of a Roman basilica or a Christian church.
AMBULATORY: a semicircular or polygonal passageway around the apse of a church.
CHOIR: The part of a church, generally located toward or in the apse, reserved for clergy and singers.
PIER: a term used for the solid mass between windows, doors and arches.
