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.
November 7, 2015 § 1 Comment
Not to get political, but this week one of the presidential candidates waded into architecturefarm territory by claiming that the Egyptian pyramids were built as grain storage by biblical figure Joseph to ensure his people would last through the mythic seven years of drought mentioned in Genesis. There may, in his words, have been aliens or divine inspiration behind both the form and the construction of the Pyramids. “The pyramids were made in a way that they had hermetically sealed compartments,” Carson said. “You would need that if you were trying to preserve grain for a long period of time.”
Well, yes. But if this theory was true you almost couldn’t find a dumber way to store grain. The largest of the pyramids contains a well-documented 2.5 million cubic meters of limestone and an equally well-documented 340 or so cubic meters of actual space. While we can argue about whether the dozens of artifacts found in the pyramids’ interior chambers represent burial rituals or carelessness on the part of granary employees who just happened to be carrying around religious artifacts, I think it’s pretty clear that 1/7400 is probably the worst net to gross ratio in the history of building. If the pyramids were in fact divinely-inspired granaries, the designer was having a particularly bad day.
Some quick math. There are about 640 calories in one cup of wheat berries. There are 4227 cups in one cubic meter. So the Great Pyramid could have held about 640 calories/cup x 4227 cups/cubic meter x 340 cubic meters/Great Pyramid, or about one billion calories of grain.
Sounds like a lot, until you do the math and realize that the average human consumes about a million calories a year. Even accounting for famine conditions and assuming that each Egyptian could get by on half of that, that means that each of the divinely-inspired granaries could have supported 2000 Egyptians for a year, or about 285 of them for the full seven year famine. Ok, ok, there were three “great” pyramids, but optimistically that means enough grain for roughly 900 Egyptians to get through a seven year famine.
Now, here’s the fun part. This month’s Scientific American has a great article on the actual construction of the Pyramids. In particular, it focuses on the work of archaeologists like Mark Lehner and Pierre Tallet, who have excavated the job site towns around the pyramids and discovered whole cities devoted to housing workers and laborers, and to managing the trade of metals, stones, and–yes–food to keep the construction sites going. Their findings are really fascinating. Among other things, there’s evidence that, far from being slave laborers, the workers who built the pyramids seem to have been ordinary citizens who may have been donating their labor out of religious devotion. And they’ve tracked trade routes as far away as the Sinai peninsula, suggesting that the organization and trading relationships that were formed to get the pyramids built served to raise the Egyptian economy far above its neighbors. The pyramids, according to Lehner, were more of a “sociological wonder” than a “technological wonder,” providing the economic and labor infrastructure that transformed the Egyptian state into a self-sustaining positive economic feedback loop that “not only created wealth for Egypt but also lifted the economies of its trading partners abroad.”
No surprise that this particular presidential candidate would scoff at that sort of Keynesian economic history. But more to the point, Lehner and others estimate that the size of the town housing the pyramids’ workforce was something like 6,000–in other words, seven times the population the pyramids could have fed if they were in fact granaries. And the towns had their own granaries to feed their residents that were far larger than the 340 cubic meters offered by the pyramids’ interiors.
In other words, the Pyramids as granaries would have been not only spatially inefficient, but not even as efficient as the warehouses in town used to feed the crews building them.
I don’t know about you, but this seems like a waste of taxpayer dollars to me.
November 5, 2015 § Leave a comment
I’ve been abroad the last couple of weeks, taking advantage of a Visiting Scholar position at the American Academy in Rome to finish acquiring and producing illustrations for the forthcoming Nervi book–more or less officially titled Beauty’s Rigor: Patterns of Production in the Work of Pier Luigi Nervi. I have a crack team of graduate students back home who are turning out the more interesting stuff–sequential images of components being fabricated and placed that really help to explain how these structures are all based on algorithmic methods as much as they are on structural principles. (We’re calling them IKEA drawings…) I’ve finalized the archival images with MAXXI, and this has given me time to sit in the Sid Bass studio up on the Academy’s fourth floor and just draw. It’s not quite a Prix du Rome experience–all Illustrator instead of 18 shades of india ink and giant easels–but this is still an inspiring place.
Today’s completed effort above in low-res. This is the Kursaal Restaurant in Ostia, one of my favorite excursions on an early reconnaissance trip in 2012. It’s a tiny seaside pavilion that’s part of a beach resort, and it’s a total gem. Nervi worked with Roman architect Attilio Lapadula on the design in 1950, which features a reverse dome tiled in his famous tavelloni. The roof is supported on a concrete stalk–and little else. A ring of columns and (originally) steel mullions did the work of balancing wind loads on the roof, which is an unusual sleight-of-hand for an engineer known for his adherence to “structural truth.”
Whatever. It’s beautiful, and it plays with expectations of structure while flooding the room with daylight from the horizon and from a large cantilevered eyebrow and light shelf. Fun to spend some time drawing through it and tracing Pier Luigi’s lines through the ceiling.