Precisely the forecasted poor conditions that we were almost sure we would find after the first phase of excavations led us to exercise extreme caution in ensuring the stability of the Cathedral by placing a set of buttressing porticos between all the Cathedral’s pillars and pilasters to prevent any possible sideways movement of any of their bases, since their foundations had been touched during the archaeological investigation. Taking advantage of these porticos, a walkway was installed above the floor level of the Cathedral, suitable both for the tourists visiting the excavations and the restoration work and for carrying out works on these, by installing a series of gantry cranes for the movement of materials and a set of guides for the photogrammetry of the remains that had been unearthed.
Along with these, other supports were installed in the most unstable areas of the site: two underpinning columns twenty metres high next to the Santa Ana façade and in the former Chapel of the Kings, and two other reinforcements in the form of a bevel in the northeast and southwest buttresses of the upper section of the transept nave. And a holding structure was installed for the underpinning and protecting of the vaults of the south arm of the transept, previously assembled during the first emergency works performed to avoid the possible falling of masonry from these vaults, a possibility postulated by the preliminary structural studies carried out by the engineers Giorgio Croci and Giuseppe Carlucio in 1995.
All these structures were made with steel and bolted joints to allow easy disassembly later on, without having to resort to blowtorches or cutting machines that could accidentally damage the historical materials to which they are fixed. And as with the initial shoring, all these support systems have been removed within the last three years, as the final stonework consolidation tasks have progressed and we have been able to structurally stabilize the Cathedral as a whole. Only the support of the north gable of the transept remains to be dismantled, until the consolidation of this part of the building that is expected to be carried out during 2015.