The double-chaired voussoir barrel vault on the Gymnasium Calidarium, Salamis Cyprus

The colonnade of the Salamis Gymnasium was excavated in 1890 (Arthur, Munro & Tubbs, 1891) and interpreted as part of a Temple of Zeus. The area was recognized as a thermal complex following new excavations in 1925 [9], which therein uncovered partially three vaulted aulae. The building is a stratified palimpsest, reconstructed over the ruins of several earthquakes. First built during the rule of Augustus, archaeologists have dated one phase of the complex to the principate of Trajan 98-117 AD [25]. Others agree on dating the thermal buildings to the II century [9]. On the base of the statues and coins found during the excavations, Karagheorgis [17] pushed the last phase to the VI century. Even though dating the complex is an open issue, in the last phase, the architects designed this barrel vault, “une voûte faite de larges dalles assemblées” [10] with double-chaired voussoirs, an anti-seismic device, on top of a thick wall of limestone ashlars. Stratigraphic data derived from an UAV digital photogrammetric survey allowed a tentative dating of the last phase of the complex. The paper will provide the graphical reconstruction of the vault so to understand its structural behaviour. We analysed the results of the survey with reference to other coeval examples of thermal buildings in the eastern Mediterranean area to provide new data for the building’s constructive phases within the late antique settlement of Constantia.