Pier Luigi Nervi,
with Gino Covre and Antonio Nervi
The Palazzo del Lavoro,
Viewed as a symbol of integration between structural and architectural invention and presented in the most important national and international publications, the Palazzo del Lavoro has fascinated entire generations. This was achieved by emphasizing, with a certain mannerism, the overly exposed role of the structure, during the third phase of Nervi’s career, that of the important international commissions when the “Nervi Style” became a repertoire of solutions to be used around the globe. The competitive tender for the construction of the 47,000 m2 pavilion that, for the Centenary of Italian Unity, was to have hosted an important exhibition presided over by Giovanni Agnelli and designed by Giò Ponti, was issued in July 1959. In October of the same year the jury awarded the project to Nervi & Bartoli, and its designers: in addition to Nervi, his son Antonio and Gino Covre, one of the primary Italian engineers of steel structures. The project revolved around the subdivision of the square roof into sixteen independent ‘umbrellas’, each 40 meters per side, separated by continuous strip skylights and made from a sunburst pattern of steel beams fixed to a central column with a variable geometry, a recurring characteristic in Nervi’s work after the Corso Francia Viaduct (1960), the Savona Railway Station (1961) and ending with the vault of the Cathedral in San Francisco (1970). The perimeter gallery is instead constituted of Nervi’s typical isostatic ribbed slabs, realized using moveable ferroconcrete formwork, based on a process widely tested by Nervi in various buildings, including the Gatti Wool Mill (1951-53). The proposal was deemed convincing for its simplicity and structural legibility and, thanks to the modular solution and differentiation in materials, it was the only submission capable of guaranteeing completion within the limited time available. As with the Turin Exhibition, site supervision was managed by Fiat’s Divisione costruzioni e impianti, directed by Bonadè Bottino, with whom there existed a relationship of reciprocal trust. Beyond the technical data, nonetheless impressive – 158 meters per side, 26 meters in height, and a total volume of 650,000 m3 – the most innovative aspect was, in reality, the organization of the building site. Work began in February 1960 and by late December the building was already complete.
Pier Luigi Nervi,
with Roberto Biscaretti di Ruffia,
Designed and constructed immediately after the War, the Hall B at the Turin Exhibition represented the first concrete possibility for Nervi to apply the principle of structural prefabrication, uniting, in a single large-scale vaulted structure, his highly personal use of ferroconcrete (steel mesh and small diameter steel rods cast in a thin concrete pour) with the extensive use of prefabricated elements. It is also the first project that tied Nervi to the important industrial clients of Turin and Fiat. The Società del Palazzo delle Esposizioni had commissioned the engineer Roberto Biscaretti di Ruffia to construct a new exhibition hall, to be used as a showcase for Turin’s automobile industry, atop the remains of the Palazzo della Moda, designed in 1936 by Ettore Sottsass and bombed during the War. In 1947 Nervi & Bartoli were awarded the invited competitive tender, proposing two substantial variations to Biscaretti’s project, based on a large hall with an apse: inclined lateral columns, in order to increase the height of the vault above grade and, for the terminal apse, a slender flattened semi-dome in alternative to the flat roof. For the realization of the vault, Nervi studied special wave-like elements in prefabricated ferroconcrete, installed on a tubular armature and linked by site-cast reinforced concrete ribs in the summits and hollows in the waves. Elegant fans connect each of the three arches of the undulating roof to the inclined columns. The apsidal semi-dome was instead realized in small, lozenge-shaped ferroconcrete tiles (formelle), used as permanent formwork and similar to the roof of the ribbed pavilion resting on four inclined arches of the successive and adjacent Hall C (1949-50).Inaugurated on 15 September 1948 and publicized as “the most beautiful building ever built in Italy”, the Hall B attracted the attention of specialized international press as early as 1949, when it appeared on the cover of La technique des travaux. Between 1953 and 1954 it was enlarged by five bays, definitively cancelling the internal porticoed garden. Between 1952 and 1953, Nervi, together with the architect Ettore Sottsass, developed a project for an ulterior enlargement, which called for a 100-meter arch on the main façade; the project was set aside after Sottsass’ death in 1953. Re-presented to the Società Torino Esposizioni in 1959 and approved by the building commission, it was later shelved by the Società, which opted for a new underground Hall designed by Riccardo Morandi.