morandi viaduct collapse in genoa

August 14, 2018 § Leave a comment

Watching this with horrified interest.  Riccardo Morandi’s iconic A10 viaduct in Genoa suffered a major collapse earlier today during a torrential storm.  The one video posted by La Repubblica shows what looks like the already damaged western tower collapsing.  There are reports that traffic was heavy, it being the holiday season, and that there was maintenance being done on the bridge deck.  Some reports say the tower was struck by lightning before the collapse, though it’s hard to imagine how this would be the cause.  Video of the rescue efforts show windy conditions, which seems more likely a contributing factor.

The viaduct employed Morandi’s classic hybrid style–each tower was a simple A-frame with tension arms that held the ends of a compression deck.  Between these were shorter spans of simple beams.  Their diagrammatic simplicity was matched by (relatively) easy construction, which meant that the system was economical for his much larger project over Lake Maracaibo in Venezuela, and for the short leap that the A91 highway from Fiumicino Airport into Rome takes alongside the Tiber.  Will be looking for further news and/or ideas about just what happened.  La Repubblica’s twitter feed has been a reliable source this morning.


talking skyscrapers on curious city

August 8, 2018 § 2 Comments

I could sit and talk about Chicago’s skyscrapers with Jen Masengarb all day–and last month I had the chance to do that (or for at least an afternoon).  Jen is now with the Dansk Arkitektur Center in Copenhagen, but she was previously the director of education for the Chicago Architecture Foundation, and in that role she very generously invited me out each year to talk to the CAF docents about my skyscraper work.

She’s sorely missed in Chicago, where she’s also been a regular guest on WBEZ’s Curious City.  This week they’re broadcasting highlights of a chat she and I had with Jesse Dukes, answering a listener’s question about the density of the Loop–why are the city’s skyscrapers clustered in such a compact area?  

The result was, as you can imagine, a free-wheeling discussion, and the edited version is a nice, concise set of thoughts on economics, politics, urban branding, and infrastructure.  WBEZ’s producers made us sound pretty efficient, and they certainly got the best out of what was a really enjoyable afternoon…

nic gianopulos

July 27, 2018 § Leave a comment

35ea1e716b307373748d6a9ec495b1b9--louis-kahn-bangladeshIn about 2003 I was in the midst of a book project on Louis Kahn, saving up research dollars and bingeing on week-long trips to the Archives in Philadelphia when I could.  After a couple of these trips, Bill Whitaker, archivist extraordinaire and friend to anyone studying Kahn, told me “I think you need to talk to Nic and Tom.”

Nic Gianopulos and Tom Leideigh were engineers at Philadelphia firm Keast and Hood.  Kahn worked with both of them early in his career, and he trusted them implicitly; they had formal roles on the Yale Art Gallery and the Parliament Building at Dacca, but Kahn sought their advice on projects he did with August Komendant, too.  The early stages of the Kimbell Art Museum occurred during one of many periods during which Kahn and Komendant weren’t speaking; Gianopulos describes seeing what Kahn wanted to do with the roof vaults and telling him, essentially, that he needed more firepower than Keast and Hood could provide.  He’d have to go “talk to Gus.”  Kahn took that advice, too.

I did get to spend an afternoon with Gianopulos and Leideigh at Keast and Hood’s offices–they were well into their positions as partners emeriti, but still kept a presence there and had several rolls of drawings to talk through with me.  As with most Kahn interviews, the afternoon went back and forth between hardcore details, philosophy, and the fondest possible memories, which was evidence that Kahn’s practice was profoundly human, gloriously flawed, and yet capable of producing work that its protagonists still found breathtaking and moving forty or fifty years later.  After the book came out I did a lecture and signing at Penn.  In the midst of the social hour afterward I felt a firm hand on my shoulder.  I turned around to find Nic, who shook my hand and said, with a smile, “you got it right.”  No review has ever meant more to me.

Keast and Hood announced earlier this week that Nic Gianopulos died on July 21, at age 93.  After his time with Kahn he specialized in historic preservation, and he taught at Penn for over 25 years.  Would that all of us can look back on such a long, productive career, and share what we learned with such joy.  Very grateful to have run across him, and to have had that brief but inspiring conversation.

iass 2018

July 23, 2018 § Leave a comment

kresge extA full week of engineering and design in Cambridge, MA, where the annual meeting of the International Association of Shell and Spatial Structures gave a pretty solid overview of the current state-of-the-art in advanced structural engineering.  I was there to give papers as part of their Working Group 17, which documents and studies historic shell structures, but sat in on plenty of interesting sessions about what’s going on today.

There was a definite flavor to the week that a lot of the past decade’s wilder speculations have been tamed by practice–foggy-eyed papers on the possibilities of genetic algorithms and full-scale 3D printing that characterized this conference a couple of years ago have given way to papers on low-carbon processes, timber structures, and labor-saving fabrication that focuses more on making processes simpler than on manhandling complexity.  For me, the signal presentation was on self-forming timber shells that relied on two-dimensional laser cutting of thin wooden sheets in patterns designed to take advantage of the material’s own tendency to shrink during curing, creating natural curvature that otherwise would have required a great deal of mechanical force to achieve.

Indeed, timber is the sexy material of the future these days, whether it’s in skyscrapers or in shells.  Its relative availability, ease of handling, and (of course) renewability make it a far more carbon-efficient material than concrete or steel, while it’s light weight and ductility allow for a range of low-fi fabrication methods that are themselves relatively low-energy.  Throw in that it’s a natural material with a range of textures and colors that seem friendly and you have a pretty convincing argument, one that’s being pursued by a huge number of research groups right now.

Historic shells, by contrast, seem a little ponderous these days, but there were good sessions on the field’s past, including a fair amount of dissection of Saarinen’s Kresge Auditorium, where the conference was held.  It’s spherical roof, along with Utzon’s graceful but almost impossible shells for the Sydney Opera House, was one of the most important controversies in the 1950s.  Nervi, among others, railed against the false simplicity of the form, and its static deficiencies are apparent if you know what to look for (hint: some of the ‘mullions’ in that elegant curtain wall are actually holding up the mid-spans of the shell’s edge beams).  And in a climate of rampant optimization, it formed a pretty good foil for many of the structurally efficient shapes that appeared on projection screens during the week.  (Hard to imagine, isn’t it, that a superstar architect could get away with facile form-making in an era where we have such convincing tools…)

IMG_9733The week’s highlight, though, was a day trip to Hanover and a group visit to Nervi’s twin sports arenas at Dartmouth.  Momo Sun, a recent MIT graduate, has done ace research on the history of the two buildings, and we were lucky to get all-areas access to both buildings.  They’re a study in variations on a theme–both are extruded, shallow parabolic shells formed with ferrocemento pans that add stiffening ribs to thin concrete roofs.  Their respective buttressing, though, shows Nervi’s growing confidence in American concrete.

IMG_9743Leverone Field House, built between 1961 and 1964, uses simple in situ props with broad horizontal beams that absorb the thrusts of the roof while providing shelter for ancillary spaces to either side of the main shell.  Thompson Arena, the hockey rink across the street, uses Nervi’s trademark system of twisted wood formwork to achieve dramatic, ruled-surface piers that reflect the structure’s need for ductility under thermal loading.  (New vocabulary–today this gets termed ‘compliance,’ which seems much more evocative).

IMG_9771As interesting are the varied approaches to enclosing the open ends of each shell.  Thompson’s end elevations are pretty simple precast concrete with some bracing mullions that run the full height, but Leverone’s are glass curtain walls that are steadied against wind forces with gently shaped truss members–and particularly expressive details at their tops that allows the shell to ‘ride’ vertically as it expands and contracts without bearing on the curtain wall.  If you look closely, you can see that the top fixture is actually a strut with two pins–one at the connection to the roof, the other at the connection to the wind truss.  It’s a similar detail, as fellow Nervi scholar Tomaso Trombetti pointed out to me, to race car suspensions that have a similar need for robust resistance on one direction and complete flexibility in the other.  (Trombetti mentioned Ferrari suspensions in particular, but this isn’t just an Italian detail…).  We debated for a while whether these steel trusses were actually Nervi’s designs, or whether they were imported to the project by local engineers–I’m out on a limb as saying that they definitely bear Nervi’s signature didactic intent, but this may need a research trip back to the archives to confirm…

IMG_9762Among that debate’s participants was Matthys Levy, a structural engineering hero to any of us who were brought up on Structures for Architects, which he co-wrote with Mario Salvador.  Levy joined us to walk us through the neighboring Hopkins Center, Dartmouth’s performing arts center designed by Harrison and Abramowitz around the same time as Leverone Field House was going up.  While it’s best known as a sort of warmup project for that firm’s Lincoln Center, Levy talked us through the use of long-spanning barrel shells for the building’s main roof spans, and to point out a handful of details that show his interest in combining architectural form with structural logic.  This one, for instance, is sort of a designer Rorschach test.  Architects are likely to see it as a sequence of oval ceiling apertures, while engineers are more likely to see it as a series of swallowtail joists that spread out their collected shear across a wider cross section as they meet the carrying girder.  That’s a Nervi touch, too, one that was best employed in the Manufattura Tabbachi in Bologna.

All in all an inspiring week.  Back home now, digesting two solid conferences, following up with a bunch of new readings, and prepping for Fall studio, which will focus on a high rise multi-university center in Chicago’s South Loop…



July 14, 2018 § Leave a comment

A solid week of building science and technology history and geekery in Brussels, where the 6th International Congress on Construction History has just finished.  After helping to organize 5ICCH in Chicago, this was the first Congress in a while where the Americans were able to relax and fully enjoy, and the range of papers, tours, and discussions was, as you’d expect, well worth the trip.

The field really does feel like it’s maturing, with the majority of the papers coming from graduate students or at least young faculty who are bringing energy, fresh ideas, and impressive findings with them.  There were still plenty of familiar faces, but I was impressed at how many new names there were on the podium and in the audience–a sign that looking back at how our construction and engineering technologies have evolved over time is proving itself as a topic of inherent interest.  It’s clear that there are distinct lines of inquiry–stone vaulting, history of contracting and administration, thin-shell concrete, skeletal iron, and vernacular building in general–that have formed consistent camps.  All of these topics were well-represented, and some offered genuine fireworks.  But there are also plenty of unexplored, or fresh finds as well.  And new territories.

Belgium has been one of the most active centers of CH for a while, now, thanks to active programs at several universities–Antwerp, Leuven, and Brussels all participated in organizing the conference, and were all well represented by students and faculty giving papers.  But it also proved to be a rich venue for examples of iron construction, infrastructure, timber roofs, etc.–all of which have large fan bases in the field.  I played hooky one afternoon to get a walking tour of Victor Horta sites in, and was happily surprised at how technically rich much of his ‘ornamental’ ironwork is–Sullivanian in both its complexity and, once you see how it was done–its simplicity.

There were at least three highlights that will stick with me.  The first was the buzz over a paper by Aleksandra Kosykh and Konrad Frommelt, done under the supervision of Werner Lorenz at Cottbus, that revealed an iron truss in the roof of the Marble Palace in St. Petersburg, Russia, from 1770–a decade or two earlier than any previously documented iron truss in France or anywhere else.  Lorenz himself gave a similarly stunning keynote talk that summarized the project he’s had for the last dozen or so years on the lost bronze truss of the Pantheon’s portico roof, just in case anyone thought that the idea was born first in the 18th century.  His research has ranged from digital reconstruction based on a demolition drawing by Borromini (!) to having local blacksmiths cold-hammer rivets made from the same bronze formula as the single known surviving rivet from the truss itself–and it’s shown definitively that Bernini did not, in fact, use the bronze for the baldacchino in St. Peter’s.  (It went into cannons in the Castel Sant’Angelo, instead).  The details will be published in an upcoming article in Construction History.

And, finally, the week’s last keynote was by Tullia Iori, of Roma Tre University, on the long research arc of the SIXXI program there, which is producing a comprehensive history of structural engineering in Italy during the twentieth century.  The talk was partly an elegy for Sergio Poretti, who co-led the project until his sudden death last summer.  The research that they and their students have produced has been insightful, the work they’ve studied almost universally beautiful, and the presentation heartfelt.  Tullia and Sergio were two of the first scholars I met doing the Nervi research in Rome and they were enormously generous and helpful in steering Beauty’s Rigor.  Sergio is much missed, but it was clear that SIXXI will continue to explore one of the field’s richest moments.

Heading to Boston next for IASS 2018.  Conference season in full swing, but Brussels will be hard to top.  Thanks to all the organizing staff and leaders of 6ICCH for a memorable and historic week.

new union station ‘tower’

June 26, 2018 § Leave a comment

Screen Shot 2018-06-26 at 9.18.57 AM

SCB Architects

I’ve been keeping out of trouble this last month with conference prep and a big digital project finishing up this week, but couldn’t let this one go.  The above image is from SCB, of their proposed extension to Chicago’s Union Station.  It’s had a pretty well-deserved thrashing in the press in the last 24 hours, but I think it’s worth piling on–if only to point out that the Station’s current stubby proportions were largely a result of its timing.  Originally designed by D.H. Burnham & Co. in 1913–one of the last projects to enjoy Burnham’s attention before his death–it had a protracted construction history.  Delayed by WWI, re-designed by Graham, Anderson, Probst, and White in 1921, and ultimately completed in 1927, a planned tower over its skylit waiting room never fully materialized, and was doomed once the Depression took hold.  Its short, four-story office ‘tower’ is all that was ever built of a planned 16-story skyscraper that would have given the station a real presence on the West Loop skyline.

Or, really, not quite all that was ever built.  Foundations were poured assuming that the skyscraper would be built, and so yesterday’s plan would take advantage of the substructure that’s already there–just not anywhere near the (ahem) somewhat more elegant proportions foreseen by GAPW:


Chicago Tribune, May 18, 1921

dsm courthouse studio final review

April 28, 2018 § 1 Comment

IMG_9173We finished a strong semester yesterday in truly noble surroundings, celebrating the end of the Des Moines Courthouse Studio project by holding our review in the lobby of the Mies van der Rohe Home Savings and Loan (now the Catholic Diocese) building downtown.  Recently restored, the Mies space looks fantastic, and six interdisciplinary teams did it justice with schemes for a truly difficult mash-up program of federal courthouse and mixed commercial and residential uses on the riverfront site of the former YMCA building.

IMG_9151I posted about the studio at the start of the semester, but basically we were exploring the possibility of putting a new Federal Courthouse on a site that the City of Des Moines would prefer to have developed commercially.  Could you, we wondered, do both?  Could you put a truly monumental Federal building on a site and still have room for apartments, restaurants, coffee shops and bars that would keep the life of the city going?  Or, as one student put it in the run up to our mid-review, can a building be urban and civic at the same time?

IMG_9161I’d say that our answer, after fifteen weeks of exploration and development, would be a qualified “maybe.”  Not surprisingly, the security considerations that go into a courthouse really mitigate against the open, pedestrian nature of a downtown mixed-use structure.  Still, student teams of interior designers, architects, and landscape architects came up with some clever strategies of separating court functions from the surrounding streets with buffers of mixed-use development, and they tackled the notoriously difficult circulation requirements that come with prisoner, judicial, and jury circulation with equally sophisticated elevatoring and logistic strategies.  What do you do with criminal defendants when the fire alarms go off?  These sorts of questions have real consequences for building design, and they make it obvious why so much courthouse design in the post-Oklahoma City bombing era have tended toward fortresses more than engagement.


IMG_9194The Courthouse controversy in Des Moines is ongoing–the Federal Courts and the City are still discussing where it will go, and it’s one of the biggest questions the resurgent downtown will face in the coming years.  We held the review in the middle of downtown on purpose, and were really happy to have a steady stream of architects and designers stop in throughout the afternoon.  That speaks well to the commitment that Des Moines’ design community feels toward the city’s development, and we’re hoping that this studio, in a small way, helps keep the conversation going.

Babafemi Hang Zheyou aerial

Babafemi Ade Aina (ARCH), Hang Gao (ARCH), Zheyu Zhang (ARCH)

Chaniara McKewon Ly river view

Deep Chaniara (ARCH), Nate McKewon (ARCH), Van Ly (ARCH)

Dobbins Niepceron Stoyanova Tegeler view from 2nd

Mimi Dobbins (ID), Madeleine Niepceron (ARCH), Alba Stoyanova (ARCH), Brice Tegeler (LA)

Hakala Peterson Barron library

Shawn Barron (ARCH), Jennifer Hakala (ARCH), Kyla Peterson (ID)

Hakala Peterson Barron river view

Shawn Barron (ARCH), Jennifer Hakala (ARCH), Kyla Peterson (ID)