ponte del risorgimento

Oh, this is fantastic…

I’m going through the various Nervi notes, books, and archival material that I’ve been collecting over the last year or so, and inevitably starting to find connections between projects that I hadn’t noticed before.  This, to me, is the best part of a research project, because at some point the themes become pretty clear and for a while it feels like everything has its own momentum.

Take the Ponte del Risorgimento, for example, a bridge in Verona that Nervi designed in 1962.  Like many projects constructed after the crest of the miraculous Italian economy of the 1950s, it suffered from the country’s sclerotic bureaucracy and wasn’t built until 1968.  It’s never gotten quite the attention that other Nervi projects of the era have, and I have to admit that when I saw it last summer I was a bit underwhelmed.  The sides of the bridge undulate so that the structure is widest over the supports, in addition to being deepest.  The depth story is pretty intuitive–it’s a doubly supported beam, and this family of structural types has its greatest bending moment over the two supports.  (OK, can’t resist–here’s the classic doubly supported beam, by Nervi student, employee, and disciple Myron Goldsmith:

goldsmith hangarIt is AWESOME when internationally-renowned engineers go out of their way to provide examples for SCI-TECH).

Anyway, you can see the similarities, and at the time I chalked the Ponte up as a good example in concrete that might pair with the UAL hangar as another good example of a statically-shaped doubly-supported beam.

But, I’ve been going through Nervi’s variable section pier designs this weekend, and something clicked.  These piers are some of his better known structural elements, about which more later, but for now it’s enough to say that they were made by twisting straight boards to match stacked metal jigs, connecting an ideal shape at one end with a (different) ideal shape at the other, creating a set of ruled surfaces:

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That’s one of the classics, from the Palazzo dello Sport.  And if you look closely at that pier, or at the image of the Ponte, above, you can see the timber form marks–both geometries were figured out and formed in the same way, by setting out the end sections as well as a set number of transitional shapes between, and then laying straight lines/boards into them.

So why would you go to the trouble to make the deep parts of the bridge bulge out, in addition to bulging down?  Down gives you greater section modulus over the support, to counter the greater bending, but what does out get you, besides a little extra lateral stability in a heavy piece of structure that surely doesn’t need it?

Ah, this is a lesson in doing your reading.  Mario Sassone writes, in his essay on the bridge in the exhibition catalogue to Pier Luigi Nervi: Architecture as Challenge:

The cross-section of the bridge varies not only in height, but also in form, going from a trapezium shape in the abutment area to an upside down trapezium in the arch area.  The width of the compression zone is then always wider than the width of the tension zone, following the alternation of moments that compress the lower fibres in the supports and upper ones in the bay.

Bingo.  Nervi could handle the tension aspect of a really big bending moment by adding more steel, which doesn’t do anything to change the shape of the bridge.  But to handle compression, he had to add more concrete, and the further that extra material from the center (neutral axis) of the bridge’s section, the better.  So the angle of the board forms changes as the need for additional compressive material changes; there’s more on the bottom of the shape over the abutments, because the bridge is getting bent in that direction, but where the moment ‘shifts,’ and causes more compression in the top of the section, toward the center of the span, the boards start to lean the other direction, making the top of the deck wider than the bottom.

Subtle, but genius, and all of a sudden what had been a nifty but less than remarkable bridge becomes part of Nervi’s long-running experiment in ruled surface formwork and an integrated example of not only section modulus at work, but also of the complex moment distribution across the section of a doubly supported beam.

Any morning with one of those moments of clarity is a pretty good morning.  Celebrated with a walk down to Forno Campo di Fiore for lunch.

Palazzo dello Sport

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The 1960 Olympics’ main arena was sited atop the hill at the southern end of the EUR district, a commanding location that necessitated a signature statement of the Games’ style. Nervi worked with aging architect Marcello Piacentini, who had been the lead planner of EUR and a leading adherent of the stripped classicism that came to represent Fascism throughout the 1930. This was, to say the least, an odd choice, and drawings in the archives show that Nervi’s approach was entirely at odds with Piacentini’s desire for a neoclassically inspired dome as a backdrop to his by then aging and already discredited suburban statement of political and corporate power.

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Nervi clearly won out, and the result was one of his more complex weavings of structure and circulation. The roof was a restatement of his folded ferrocemento ribs at the Torino Esposizione, here wrapped into a circular plan and propped up by attenuated in situ concrete fans. These, in turn, were supported at the edge of the seating bowl by inclined piers that echoed those at the Savona rail station, with a section that twisted to minimize interference with circulating spectators below. The concourse itself was covered by a ring of propped, double cantilevered concrete bents, and enclosed by a steel-braced curtain wall system that echoed the contemporary exterior of the Palazzo Lavoro, and the underside of the seating bowl was formed from lamella ferrocemento pans that were similar to those being used for the Palazetto several miles north.

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In some ways, the Palazzo was the crowning moment of Nervi’s busiest, most productive period. Between 1956 and 1962 his office completed both Olympic sports arenas and the Stadio Flaminio, the Palazzo Lavoro in Turin, Marcel Breuer’s UNESCO building in Paris, the Savona station,the Pirelli tower in Milan with Gio Ponti, and the George Washington Bridge bus station in New York. Nervi turned 70 in 1961, and while there were several office towers, ecclesiastical projects, and bridges to come, this represented the peak of the office’s production.

As such, the Palazzo can be seen as a summation of the various techniques that Nervi had perfected in the previous decades–the corrugated, prefabricated concrete roof, the transforming column, the statically expressive bents and the transforming column sections here all took previous experiments and collaged more refined, polished versions into a single whole. It’s kind of like a greatest hits album.

And that’s a double-edged sword. Like most greatest hits collections, the Palazzo is a convenient place to see many of Nervi’s main themes in action, but whether they hold together in a consistent narrative or not is another story. The building section is complex enough that it isn’t really easy to grasp unless you spent some time moving through it (for the record, the security guard who let me in wasn’t terribly interested in such meditations…). And unlike the smaller Palazetto, it’s hard to understand the building as a whole. The Palazetto is a single idea relentlessly expressed: a lamellar dome, lifted above seats and circulation by a ring of structural forks, and inflected to bring in daylight. The Palazzo can’t quite be summed up like that. It’s a necessarily more complex building, but there isn’t the single diagrammatic stroke that makes it cohere. It’s also true that daylight plays a far smaller role here (in fairness, the upper level windows have been blocked off for daytime events, so you can’t really tell what it would have been like flooded with sun).

Still, the building is impressive, and for such a large arena (16,000 seats) it is remarkably well-scaled. And it’s proven continually useful, both for sporting events and concerts.

The Rome excursion is wrapping up nicely. This was the last site visit I had scheduled, though there’s a bridge in Verona, and of course UNESCO in Paris, but the next two weeks are going to be a combination of backpacking and the triennial Construction History Congress. Posts will be a bit sparer while my partner and I hit some spots on the architects’ backpack tour that we’ve both somehow missed in our travels. Hope to see many of you in Paris next week…

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Cantiere sperimentale di Nervi e Bartoli

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A large part of Nervi’s success was due to the fact that he wasn’t only an engineer/designer, he was also a builder, with his partner Bertoli. More than one of their designs–Turin Esposizione in particular–came about initially as construction contracts and involved their redesigning to suit some of their advanced techniques. Those techniques were often the results of experiments conducted in their testing yard in southern Rome.

Which is pictured above. The MAXXI Archives listed a warehouse on Via Magliana, south of Trastevere and near the Villa Bonelli train station (on the way to Fiumicino Airport). It seemed relatively easy to reach, and since I was on a winning streak yesterday with the old Gatti factory, I added 100 minutes to my ATAC card and headed south. It took some walking around, but from the parallel (and higher) Via Magliana Nuova I could see the corrugated roof line, and I knew that this was not only the warehouse, but it was the 1945 ferrocemento warehouse that formed the centerpiece for their experiments in concrete.

It’s now a parking lot and car wash, which makes it semi-accessible. The warehouse itself is in fairly rough shape. There are a number of areas where the thin concrete has spalled off, probably due to corrosion of the metal mesh underneath. That’s not good, but it does reveal the mechanics of Nervi’s system:

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You can see the metal mesh there, and in the ceiling you can also see that it was combined with more traditional rebar in spanning (bending) elements:

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This warehouse is itself an interesting experiment. The corrugations give the walls much greater effective depth than their 1-1/2″ thickness, and the same folds in the roof make the thin shell behave like set of deep beams. You can see, though, that the construction was difficult, especially around the windows. And the result is frankly pretty unlovely, even if it’s structurally clever. While Nervi didn’t use this particular system in warehouse construction, it’s a clear precursor to the corrugated roofs at Turin and the Palazzo dello Sport.

There are other structures on the site that appear to be the same vintage, and I’d wager that some of the contain other Nervi experiments. That will have to wait for another trip, though, since the parking lot attendant was pretty skeptical of my motives. I think there’s an argument, and maybe a future studio project, to make the old yard into some sort of museum, though, because if there’s one site that encapsulates the Nervi ethic, I think it would have to be the place where he and his engineers actually got their hands dirty and tried these things out. There must have been some spectacular failures here, and you can imagine the prosecco flowing freely when an experiment proved itself.

Lanificio Gatti, a happy conclusion

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Lanificio Gatti–conclusion

Thanks to the incomparable staff here at ISU’s Rome Program, today’s attempt went, um, a bit more smoothly than the last. Armed with a formal introductory letter, I walked into the appropriate Fiat dealership (June madness sale on Cinquecentos!) and explained my quest to the manager.

As fun as it’s been to talk with building owners and caretakers who know and appreciate what they’ve got, this was even more fun. Nervi is a fairly well-known heroic figure here, and when I told the manager that I wanted to see his garage, “I disegni di famoso ingegnere italiano, Nervi,” he looked at me like I’d lost my mind. His English was better than my Italian, not by much, but enough to let me know that it was just a garage, nothing special.

I showed him the classic image on my iPhone. “si, si…È stato progettato da Nervi,” I told him and his eyes got just a bit wide. He walked into the back office and got the keys,

And sure enough, there it was, the iconic isostatic slab that combines construction technique and expressive static form do fluently. I’ve been seeing this image, and been impressed by it, since my first architectural history class, and it was a powerful thing to stand underneath it. The trick here is that it’s really a simple two-way waffle slab. But a normal waffle slab is all 90 degree corners, because those are easy to build. And even though you can coax loads into turning 90 degrees, they kind of don’t want to–they really want to flow, river-like, into the nearest column. Nervi was able to construct this more elaborate shape by setting up molds for each unique pan shape and having workers bend wire mesh over them, after which they slathered a thin layer of cement over the mesh, entombing it and guaranteeing a monolithic element. These pans were laid out on simple wooden formwork, reinforcing bars were laid in the resulting trenches, and a full waffle slab was poured on top. The result was slightly more efficient in terms of static performance, and much more expressive.

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“E famoso?” he asked. “Molto,” I said, and I explained as best I could that the ceiling inspired later buildings like the Palazetto. He was impressed, and obviously happily surprised. An employee dropped off a car while I was taking pictures, and I could hear their conversation in the background. “Il famoso ingegnere, Nervi,” the manager said, pointing up at the ceiling.

We had a nice chat on the way back to the dealership, as best we could. I explained to him that this was all maybe for a book, that I was on “un itinerario di Nervi,” and that students in America–especially mine–learned a lot from the structures Nervi designed. He said he certainly knew Nervi’s work, especially the Stadio Flaminio, which seems to be the one everyone knows. He shook his head as we said arrivaderci. “Cosi,” he said. “Il garage es famoso.”

I was glad to see this particular site occupied and well-maintained. The handful of folks I’d asked about it hadn’t known where it was, or if it still existed. Despite Nervi’s renown, that sort of response usually means the building is forgotten, abandoned, or worse. I have a feeling that the next layer of Nervi sites will have slightly sadder results–water towers, warehouses, etc., that were important to his development as a designer but that wouldn’t be much noticed unless you knew what you were looking for. But Gatti has survived, and this lower level continues to prove useful as a storeroom. For Lancias and Fiats now, instead of for wool, but the widely spaced columns handle the turning radii of the cars as well as they must have handled fork lifts in the 1950s. A good outcome to a rather long search, and a really enjoyable morning. The best part is that the manager and I both have good stories to tell.

Kursaal Ostia

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Nervi was brought in to the 1950 project to rebuild the Kursaal beach club at the invitation of Rome architect Attilio Lapadula, and he ultimately contributed two pieces to the overall plan: a diving tower (which, I’m pleased to have learned, is a “trampolina” in Italian–perfect) and a small restaurant.

The restaurant’s ceiling took the wrapped lamella geometry of the Turin Exposition Hall’s Salone B and refined it considerably. Where the earlier project had some geometric errors, here the layout of the pans followed rigorously the principles of similar geometry and proportional scale that led to precise approximations of logarithmic spirals across the ceiling surface. More provocatively, Nervi turned the curvature of the Salone ceiling inside out here–the ceiling is actually conical, and it opens outward toward the ocean views.

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That’s a bit hard to capture in photographs, but the structure is both clever and, even given its small scale, something astonishing. The entire ceiling is supported by a single central pier of reinforced concrete that blossoms into the ceiling pattern. There is no support whatsoever at the edges–the ceiling literally hovers above a lower, perimeter structure that supports a continuous concrete “eyebrow”. This piece shelters outdoor seating while bouncing daylight into the restaurant, illuminating the underside of the concrete roof with reflected daylight. The resulting space is both bright and shady, with an even wash of diffused light and an almost eerie sense of lightness.

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How the inevitable roof deflection is handled is a mystery waiting for a more detailed session in the archives. The structure has had problems–the manager told me that part of the eyebrow had collapsed some years ago, but the Kursaal took that as an excuse to renovate the entire pavilion, including the upper clerestory that is now just the barest skin of mullion less glass. The renovation also stripped off some of the plaster on the roof’s stem, exposing the rough board form concrete and–happily–giving a good idea of how this lower portion was built. It’s a gorgeous space, and even though it stands as one of the smallest things Nervi designed, it condenses a lot of structural theory and gymnastics into a tiny package.

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The diving structure, which featured the Kursaal logo rendered in reinforced concrete, was not so lucky. Just 29 years after its construction, the salt air of the beachfront site took its toll, and with grave corrosion problems evident the tower was razed and rebuild in laminated timber. The forms and general configuration have changed, but the profiles are necessarily bulkier and a it less elegant.

I came away impressed by two things. Firstly, this is another example of Nervi playing not only with structure, but also with light. Just like the ceiling at Chianciano, this one brings in daylight at the edge of the structure, making it seem to float and defying our expectations of what a sturdy structure “should” do. There’s a touch of the baroque, here, and it shows both Nervi’s confidence in the overall performance of the tactic (in this case a Johnson Wax-like mushroom slab, an idea that would be deployed on a much larger scale at the Palazzo Lavoro), and his desire to make the structure do something experientially. Which it does.

The other thing that has been universal in these little quests has been the immense love that people feel for these spaces. The manager who showed me around was obviously a huge fan of the building, and the enthusiasm he had for Nervi and for the project’s history more than made up for a rather serious language deficit on my part. It was clear that the restaurant was the most popular on the Lido in large part because it was such a comfortable but captivating space. And, just like the Sala Nervi at Chianciano, the designer’s name has become part of the club’s branding campaign:

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Esposizioni Torino Salon B

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Nervi’s earliest work in Turin came with the construction of an exposition hall in the city’s riverfront park in the aftermath of WWII. Because of its industrial importance, Turin had been bombed heavily, and part of the city’s reconstruction involved a precinct that had been devoted throughout the 19th century to public parks and expos. Fiat needed room to show off its new cars each year, and commissioned its in-house architect to design a large hall as part of a complex that included a theater and restaurant.

Nervi and Bartoldi received the commission to build the main hall, and the result of their discussions with the city and Fiat was a comprehensive re-design that used lightweight precast elements of ferrocemento to span the main hall, and two lines of poured in place fans and piers to support these. Like many of their projects, their system–an extension of their work on the Orvieto airplane hangars during the war–proved both economical and quick to build. It’s repetition, it’s ability to include skylights (closed during my visit, natch), and it’s sculptural form all combined to add a powerful visual grain to the vast space below, too.

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At the end of the hall, the architectural plans called for a rather awkward apse, semi-circular in plan, and here Nervi proposed a change in detail as well. Building on an idea first explored in a bus garage they constructed in 1945, the revised ceiling plan for this apse took the diagonal grid of a lamella arch system, which they had used at Orvieto, and literally twisted it around the circular form. The resulting diagonals traced intricate spirals across the dome that mimicked precisely the logarithmic shapes of pine cones, sunflowers, and the Nautilus shell. By using similarly scaled pans, Nervi and Bartoldi were able to construct this complex shape with relatively simple means, and this experiment provided the basis for future work at Chianciano and the 1960 Olympic sites.

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If you look closely, you can see that they didn’t quite get the geometry right–the third row up from the bottom has much longer pans than the rest of the roof. Eventually they’d get it right, though…

The Salone B and it’s later cousin, Salone C, are both still in use and well-maintained by the city. There was a rather fantastic show up over the weekend, in fact:

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Palazzo Lavoro

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One of my quiet goals for this trip was to get inside the Palazzo Lavoro in Turin. Nervi designed this for Italy’s centennial exposition in 1961 and by everything I had read it was a lost classic of postwar architecture. At the time it was huge news, in all the publications, and even included as a canonical building–alongside 860-880 Lake Shore Drive and Ronchamp–in some texts. It was the flagship pavilion at the exposition, and as such it’s gigantic, 160 meters square, and nearly 30 meters tall. And it’s detailing and structural expression are among Nervi’s best.

So why is it now a fairly obscure relic? After the fair, there was never any definitive plan about what could be done with it. Turin suffers from an abundance of exposition facilities (and, after the 2006 winter Olympics, sports facilities) and not enough action to fill them. So, as my guide told me, the Palazzo was “constructed 50 years ago and abandoned 49 years ago”. As it fell from use, it also disappeared from the press, and despite numerous proposals–community college, sports arena, shopping mall–there really isn’t that much you can do with such a giant volume.

Through some connections I made in the archives last week, I hooked up with a design firm called comunicarch that arranged for me to visit and to get inside. Their partner showed me around, and she explained that the competition was held only two years before opening day–not atypical for Italy, but a schedule that eliminated any but the most efficient approach. Nervi won with a scheme that violated the competition’s clear call for a “column-free space,” a rules violation that led to a lawsuit but that ultimately provided a solution that was faster and cheaper than any other. The key to the design was a standardized column, tapering from a cross shape at its base to a circle at the top using Nervi’s system of twisting board form construction. At the top of these, Nervi proposed concrete umbrellas, but ultimately these were rendered in steel to ease and speed construction. Each parasol is 38 meters square, leaving 2 meter gaps between them that are simply covered with skylights. The structure, backlit by a bright sky, seems impossibly light and hovering, and the volume beneath it is enormous and atmospheric:

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I am not easily impressed by large spaces, but this was breathtaking when we walked in. The only thing I’ve seen that was similarly vast and so well scaled was the Moffett Field airship hangar in Palo Alto–a space so vast that it actually induces vertigo. We were lucky to have a sympathetic security guard who walked us all over the building, up on the galleries to get close to the roof:

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And around the exterior to see the curtain wall, which is all steel:

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The sunshades are precise, sharp blades that help to break down the bulk of the building from outside–and they don’t appear on the north facade, which Is absolutely right in terms of solar geometry. The supports are gracefully shaped in steel. They each change in plan from a circle at the base and top to a thin blade in the middle, expressing their wind load-bearing function. The entire thing is vast but richly grained–it must have been both a thrilling experience to walk into, and yet comfortable to spend time within. Gio Ponti did the exhibit design, which wove between the giant piers in a much more casual, organic manner–the contrast must have been intense.

It was incredible to see it first hand–one of the most stunning site visits I’ve ever made. But it was also quite bittersweet, because the structure is virtually derelict. The cladding has whole panels missing, there are piles of moldy furniture throughout its galleries, and it has become overgrown and populated by birds and feral cats–our security guard kept a broken pool cue with him while we walked around, just in case. A recent proposal to transform the space into a retail center has apparently just fallen through, and while it would have carved that grand space up into dozens of cluttered shops and arcades, it would have funded the restoration of the structure. As of now, the Palazzo’s future is unclear, but after fifty years of neglect and with no clear re-use ahead, it is descending rapidly into an unrecoverable ruin. While it may have fallen out of the history books, losing such a vast and humane space would be a tragic loss of a great postwar building.

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Savona

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There’s an old joke about the crusty Yankee who wins a day trip to New York. On his return, his friends ask him what he thought of the city. “Well,” he says, “there was so much going on down at the depot that we didn’t see much of the town.”

This is a slightly more obscure Nervi work–one that doesn’t show up in a lot of the classic books, but that has always seemed particularly rigorous to me in both planning and detail.

Savona is a small city on the Ligurian coast. It’s not really the image that comes to mind when you hear that, however–more like the transit point for beach goers who are getting off the train from Turin and Milan and who are getting on buses to somewhere lovelier. Still, that’s a lot of folks, and the train station Nervi designed there was undoubtedly a response to the city’s position as a major transfer point during summer weekends.

If nothing else, the train ride down from Turin emphasized the scale of the problem. The station itself is built into a hill, so you go down from the tracks into a long, curving corridor that emerges directly on the main level of the station. From the drawings, it looks like this was supposed to be the only level originally, but you now go down another set of stair to get got the street and the main bus roundabout.

So the section diagram works with the slope of the site, and the structural diagram basically extends perpendicular to the one circulation move across the site. Two rows of concrete piers that transform between rectangles set at 90 degrees to one another hold up a roof made of precast concrete vees. These run parallel to the circulation flow, but perpendicular to the main direction of the station. So as you turn to get your panini, or birra, or to use the bathrooms, the station changes its orientation. It’s a richly grained interior, one that’s defined entirely by the structural ceiling.

The piers themselves are good examples of Nervi changing a column section along its height to balance and ideal structural shape with planning logic. In this case, the columns are smashed flat in the plane of the glass curtain wall that runs along the front, maximizing floor space, and they twist as they rise so that they meet the ceiling beam above in the other direction. The column thus provides some lateral resistance to the structure in both directions, but with less useless material than if it had been a solid square section. And, the columns are pretty lovely:

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Nail patterns are exactly the same as on the Corsia Franca, no surprise since they were built at about the same time. The curtain wall has some interesting moments where a system that wants to meet at right angles now has to slope to match the rising edge of the column–but that makes sense given the less onerous demands placed on it.

Overall the station is in good shape, though the architecture and a more recent renovation get in the way of Nervi’s big space. There’s a lot of solid around the outside, which is climatically right given Savona’s Mediterranean location. But that makes the building seem bulkier than it probably needs to be. And the proliferation of “cabins” inside has filled up what must have once been a more compelling space–this is the “Stansted problem” three decades before its time. You can’t make money off of big open space, but you can carve that space up into little sandwich-and-coffee pavilions and make a tidy profit.

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Not that I didn’t do my part to support said cabins. After a long walk around the town, I can confirm that provincial Italian cities shut down for Sunday afternoons, so a panini at the station made do for lunch. A lot–or enough–going on down at the depot indeed.

Stadio Comunale, Firenze

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Nervi’s breakthrough commission–at age 34–was for Florence’s main stadium, and both the expressive sensibility that would appear in the rest of his work and the architectural compromises his engineering was forced to undergo are present even at this early stage,

The stadium is, in many ways, not unlike other concrete stadia of the era. It is supported by a regular march of concrete frames, upon which a deck of horizontal treads and vertical risers form the base for the seating above. The frames are reasonably well detailed for 1932, but it is the stadium’s roof and it’s three helical staircases that marked Nervi as an emerging talent. The roof is supported by curved cantilevered beams that thicken toward the root–and then divide into two branches, one spanning the rear of the stand, the other diving into the frame below. Their respective tapers follow static principles, thickening where bending forces are greatest, and tapering elegantly to show that this force dissipates toward the ends. It’s a masterpiece of subtly didactic structural form.

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The helical staircases are far less hewn to explicit structural form, but they’re incredible pieces of structural sculpture. Nervi faced the problem of exiting spectators from the rear of the stand, and then returning them to the concourse directly underneath. A simple scissor stair would undoubtedly have sufficed, but Nervi was clearly inspired by the desirable flow of the crowd, and the the stairs are, as a result, semi-circular in section. To support these, the story goes (yet to be confirmed, but utterly convincing in its simplicity) that Nervi had no choice but to design mirror-image helical beams that supported the stairs at their midpoint, because there was simply no way to mathematically model the load that the stair would impart. Whether true or not, this is a striking instance of his claim that the best engineering was intuitive, rather than strictly mathematical. And the stairs are, of course, still standing.

As for the architectural compromises, there’s that tower, which has more to do with Fascist aesthetics than with any real function. And the exterior of the main stand, the one with the roof, is a sobering example of Mussolini classicism, stripped of any humanizing detail:

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The stadium is in good shape, generally, and it is still home to Florence’s football team. And it hosts big concerts, like Madonna, who’s playing there tonight. Her security thought it was pretty funny that I thought I might get closer to take some detailed shots, so these will have to do for now.

There are some areas of concern, in particular the famous roof, which has been covered by metal cladding–not sure whether this is suggestive of water infiltrating the concrete, though that would be a good guess given its era, the lack of great waterproofing materials then, and the relative flatness of the thing.

Sala Nervi, Terme di Chianciano

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Nervi was commissioned to design the ceiling of a ballroom at the Acqua Santa mineral spa in 1952. It was the third of his ceilings to feature a construction technique of diamond ferrocemento pans, each with the same shape, but in concentric rings of different sizes. The result, apparently unintentional, was a series of interlocking logarithmic spirals, a visual effect that gained a great deal of attention. (I’ve written about the geometry of these roofs here). The two previous iterations of this technique came at the Turin Exposition Hall B (1947) and the Kurssal at Ostia (1950). At Chianciano, my guess is that Nervi had a client who knew what he wanted, but didn’t want much else. Nervi had nothing to do with the rest of the building:

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Which is certainly not bad as a piece of postwar international style modernism, but also isn’t exactly structurally expressive–or legible.

The ceiling is stunning, though, and from what I can tell it has a far higher level of finish and detail than the earlier two instances, an example of Nervi learning from doing a similar thing over and over again. The Palazetto dello Sport came a few years later, and obviously learned a great deal from this project, too. One thing that is unique about this instance, and that shows up a little bit in the eyebrows of the Palazetto, is that the roof itself peels up from the concrete net toward the edges, letting in light around the perimeter of the ceiling and making the structure seem particularly lacy:

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It’s in remarkably good shape, and still used as a ballroom–a number of elderly couples were ballroom dancing to lounge music in it when I snuck in. The vibe at the spa–which was also the setting for Fellini’s great film 8-1/2, was decidedly in the ballroom dance mode. The managing director gave me a tour, and pointed out that the room’s acoustics are lamentable–a predictable shortcoming in an elliptical room with travertine wall paneling. I’m going to guess that Nervi had little to do with either the shape or the finishes–the former looks like it came out of a larger response to a master plan for the park, and the latter, well, let’s just say there was probably a reason Nervi’s office always published carefully cropped photos of the ceiling alone. Sort of “from the waist up.”

It was a good day trip, too. The ‘Sala Nervi’ itself probably isn’t enough to draw architectural tourists from Rome or Florence–it’s about halfway between the two–but as requested by my gracious host, I will point out that the Spa’s waters have a reputation for curing all sorts of digestive ailments. And the taxi ride from Chiusi, the nearest train station, is 20 minutes of dramatic scenery and death-defying curves that are, in the local style, taken in both lanes at once.