Catenary arches were used in Spanish Art Nouveau architecture by Antonio Gaudí (1852–1926). The theory of the chain, which is based in the shape of a hanging collar, was proposed by Robert Hooke (1676) and was used by Christopher Wren in Saint Paul’s dome (1675). British school modern mechanics theory was introduced in Spain by Spanish borbonic military engineers as well as by Catholic Scottish and Irish families during the eighteenth century. The assessment of some drawings of gunpowder warehouses, which were found in the collection of Mapas planos y Dibujos (MPD) of the General Archive of Simancas (Archivo General de Simancas, AGS) (AGS 2014), have revealed the use of the chain theory in Miguel Marín’s projects for Tortosa (1731) and Barcelona (1731) as well as in Juan de la Feriére projects in A Coruña (1736). Built evidence has also been found: The Carlón wine cellars in Benicarló, which were built by the Irish O’Connor family (1757). The analysis of these examples demonstrated the arrival the chain theory to Spain during the first half of the 18th century.

Limit analysis is a commonly used method in the assessment of masonry constructions. This article deals with the use of limit analysis in order to study the equilibrium conditions during the intermediate building stages of the Gothic apse in Tortosa cathedral (1345–1441). This analysis is typically used in completed structures, but its use in the intermediate building stages may provide relevant data beyond the existing historical information. The design of this heptagonal apse entails a greater calculation complexity than the cathedral’s central body. Besides, the intermediate building stages generate asymmetry situations at the pillars. The results obtained shall enable us to determine the building stages in which the structure’s equilibrium may have been endangered, and therefore a temporary thrust countering system was required. Two different graphic statics strategies have been used. These strategies are based on the same principles, but imply a different degree of simplification.