The Montreal Stock Exchange Tower by Luigi Moretti and Pier Luigi Nervi (1961-1965)

This essay is part of the studies on the relationship between architecture and construction techniques in Italy in the twentieth century. The analysis is based on the investigation, through archival documents, of the logics of the architectural genesis of the works examined and on the study of the techniques used in the building construction process. The subject of the essay is the Montreal Exchange Tower, designed by Luigi Moretti (architect, 1907-1973) with the structural consultancy of Pier Luigi Nervi (1891-1979), and commissioned by the Società Generale Immobiliare of Rome. The tower, long considered one of the world's highest reinforced concrete skyscrapers in the world, housed an important financial center. The structure of the building was formed by a cruciform core with four large angular pillars. Like other great works by Nervi, the system was tested by modelling at the Ismes Laboratory of Bergamo, the main experimentation center in the history of twentieth century Italian structural engineering. Starting from the studies developed on Moretti’s project by architectural historians, this study intends to investigate the construction aspects of the building. A key topic of the discussion is the structural genesis, considered as the combination of Moretti's morphological research and the construction system optimization process pursued by Nervi. The Montreal project is not the first collaboration between Moretti and Nervi, but it is undoubtedly the most complex, and was developed when both designers had gained an international reputation. The tower, that has not yet been fully considered in the studies on the 20th century Italian construction history, contributed to represent the links between architectural design and structural engineering in the Italian scenario abroad, testifying, the results of the collaboration between two designers that experienced the architectural culture and the structural research of the twentieth century, thus participating in the development of the national context.