Placing the keystone of the vault over the presbytery in Tortosa Cathedral

Identifier:  PC:2008

Handle: https://hdl.handle.net/20.500.11797/PC2008

Authors:  Lluís Guinovart, Josep; Costa Jover, Agustí; Coll Pla, Sergio

Abstract:
The main keystone of the presbytery of Tortosa Cathedral (Spain), known as Clau Major, is an element which execution involved a major challenge in the construction process. Its iconography represents the Coronation of the Virgin Mary, and it was placed on 27 September, 1439. Its construction was a lengthy procedure between 1428 and 1440, beginning with the definition of its design (1428), and culminating at the point at which it acquired a full structural function (1440). The scale and the weight of the clau meant that auxiliary measures were extremely important in its positioning. A temporary column, called pilar major, was built (1428-1440), which performed the structural functions of the keystone. When it was removed, the clau adopted its true function in the construction. Recent studies have enabled us to determine its overall geometry and the auxiliary measures necessary for the construction of this Clau Major.