■ Part 1. Buttresses in Classical Architecture
The Greek colonial temples of the 6th and 7th centuries CE featured a flat timber roof supported by massive, vertical, marble columns. Classic examples of these early sanctuaries are found at Paestum, near Naples and Salerno, Italy, in the Temples Neptune, Ceres, and Hera. The latter has been best recognized as “the Basilica,”1 , 2 because of its classical architectural features. The Temple of Concordat Akragas (Agrigento) is equally exemplary, located on a plateau overlooking the southern coast of Sicily ( Fig. 1.1A,B ).
In each instance, the weight of the timbered roofs was offloaded rather simply, to columns arranged at the periphery of the overhead structure. Over the ensuing centuries, various more complex roof designs were introduced. Vaulted roofs of limestone, brick, and mortar required concomitant change in the design of buttresses, sufficient to bear significant weight and offloads. Barrel vaults, by example, were introduced in the roofs of sanctuaries at Lyons (St-Martin d’Ainay), Lesterps (Civray), and Carcassonne (St-Nazaire) in southern France. Quadrant vaults were later erected at Clermont-Ferrand (Notre Dame du Port), Issoire (St-Paul), and Conques, all in south-central France. Cross-vaults were utilized at numerous locations in northern Italy (Milan/Lombardy), then Germany, northern France, and southern England3 – 5 ( Fig. 1.2A,B ).
In general, the offloads of these immense structures were borne by hidden ribs, vaults, architraves, cross-struts; obscure internal piers, built-in butts; more obvious capitals and columns, pillars, and struts of varied sort; and thickened walls and counter-walls. Vertical pilasters and ribbing were adorned by gabions, caryatids, and telam-ones, featuring female and male sculptures.
As a means of transmitting even greater stress loads of the massive roofs, further permutations of the buttress principle were required, including placement of the buttresses beyond the primary sanctuary to assorted outlying edifices. This permutation is well represented by the flying buttresses at the Abbey Church of Cluny III (Saone-et-Loire, near Macon, in east-central France), built in the 11th century CE, and by the Duomo, the cathedral of Milan (in northern Italy), initiated in 1386 ( Fig. 1.3 ).
Gothic builders enjoyed wide use of the flying buttress and its associated support structures in cathedrals at Notre Dame (Paris, France), Chartres (Eure-et-Loir, southwest of Paris, in central France), Amiens (Saint-Acheul, in the north of France), and at Westminster Abbey in London, England ( Fig. 1.4A,B ).
The flying buttress allowed load forces to reach the upper part of the vertical pillar, and then the lower portion. The pillar was usually capped, by-weighted, and, in some cases, made strikingly decorative with peripheral pinnacles, statues, elaborate brackets, crockets, or knotcrockets. Other adornments, such as gargoyles, gabions, or baldachinos, were featured at the midheight of the buttresses but bore no significant load forces ( Fig. 1.5A,B ).
The utilization of buttresses and the principles of buttressing flourished between the 12th and 14th centuries. Notably, the flying buttress and other structural embodiments allowed sanctuaries to reach profound height and size, diminished the risk of conflagration associated with timber roofs, and permitted spacious, vaulted aisles. Cutouts for clerestory windows offered the secondary benefit of improved internal lighting ( Fig. 1.6A,B ).