November 28, 2015 § 2 Comments
Trying to keep the cranberry sauce away from the laptop this week as the final illustrations for the Nervi book come together. Thanks to an ace team of grad assistants (and this year’s MVP GA Ben Kruse) we’ve been able to put together what should be one of the most extensive collections of new Nervi drawings yet. I’ve shown a couple of these previously, and for the most part they capture the stunning patterns that emerged from Nervi’s two-fold process of structural design and fabricational algorithms.
But not everything Nervi touched turned out to be so elegant. His work as a consulting engineer, largely in the last two decades of his career after the Rome Olympics, was mixed. The purity of his processes, which he was able to hone and clarify when he was making the decisions, became compromised when faced with architects who brought competing values to the table or–worse–misguided interpretations of Nervi’s own work. Some of these collaborations worked well. Harry Seidler, for example, channeled Nervi’s understanding of static form and construction-based component design in much of his work, and when the opportunity to bring Nervi in as a consultant on three projects arose, Nervi’s contribution was essentially to bless the assumptions Seidler had made, and to offer some suggestions as to process and detailing–the story of Nervi’s “fee” for this work is one of the best discoveries of the research.
Other collaborations were more troubled, in particular Nervi’s work with Luigi Moretti for the Place Victoria in Montreal. Moretti had re-emerged in the 1950s after an early career as fascism’s favorite architect. Rehabilitated, he led an all-Italian team of developers, designers, and contractors in building Place Victoria, Montreal’s tallest skyscraper at the time and, briefly, the tallest concrete tower in the world. Nervi was involved from the earliest phases in 1961-62, but his work was frustrated by Moretti’s formalist impulses, by gravely erroneous assumptions about Canada’s booming economy and North American elevator standards, and by Montreal’s brutal climate.
Moretti’s scheme originally called for three identical towers, each of them arranged at a 45° angle to the street to provide views. But the resulting slender forms meant miniscule floorplates. Early plans for elevator provisions were based on Nervi’s work for the Pirelli Tower in Milan, but these relied on more relaxed Italian standards for waiting times, and on the fact that Pirelli had been a corporate tower. Rental properties in America and Canada typically included provisions for elevator service that would equal that of the nearest competitor, and I.M. Pei’s Place St. Marie, just a few blocks away, had recently opened with the city’s fastest system. The redesign that followed doubled the number of elevator shafts in each tower, wrecking the already weak net-to-gross ratios of the slim floors. The scheme was hastily redesigned with two towers set parallel to the street, although as the market cooled in 1963-64 only one tower was ultimately built (see section above).
Further issues emerged in the detailing of the structure. Nervi proposed a system of four corner piers supplementing a central core, all tied together at regular intervals by outrigger trusses. Collectively, the system acts much like a skier balancing on poles held at arms length, and this system braces many concrete high rises today (including Trump Tower in Chicago). But the system carries with it a nearly unavoidable thermal problem, in that the outside columns and interior core risk huge temperature differentials, particularly in Montreal where temperatures could sink to -20°C easily. The resulting thermal shrinkage of the exterior columns would result in a difference in height between them and the central core of several inches, stressing the trusses and causing floors to slope toward the exterior.
Nervi’s solution, finalized relatively late in the process, was to clad the columns in loose-fitting precast jackets with insulating cavities fed with warm air from the offices. In the energy-rich 1960s such a solution made sense, but today it is a costly and inefficient method. Worse, for Nervi, it radically altered the profiles of what had been elegant, tapering piers. What you see today in the tower is the proportion of the structure plus its “parka” of air and precast. Moretti actually preferred the thicker piers, and Nervi graciously agreed with him in public, but compared with some of Nervi’s other, more gymnastic structures (and particularly the slimmer exterior columns of Seidler’s Australia Square), Place Victoria reads as a bulky, stodgier cousin.
Still, it’s an important piece of the Nervi story, in part because it’s useful to see the problems he ran into as a consultant, but also because the 3-1/2 skyscrapers he worked on (1/2? You’ll have to read the book…) presented a neat foil to the purity of his longspan works in general. Thermal issues haunted him constantly since the near failure of the early Orvieto hangars, and here they came back with something of a vengeance. But high rises, despite their apparently simple program, are far more complex organisms than hangars or arenas, and the need to provide for elevators, for lobbies, for views and for services at each floor all moved the Place Victoria solutions away from the crisp elegance of, say, the Palazetto. As such, the chapter on skyscrapers could be subtitled “the exceptions that prove the rule,” since they show how Nervi’s best work was often, as Guy Nordenson has pointed out, for the simplest programs.