June 2016


by Don Friedman on June 30, 2016

Know any blacksmiths? There’s a job opening right now with the New York City Department of Parks and Recreation.

This might sound like a joke* but it’s serious. Blacksmiths shape iron and steel in complex three-dimensional configurations that are not easily achievable using other methods.

The introduction of CAD/CAM cutters allows for extremely complex and precise 2D work, but the conditions of steel work (high temperature, working with a material with a high yield stress) are not amenable to the best technologies for 3D. I don’t expect to see steel 3D printing anytime soon.

On two different projects in recent years, we had blacksmiths (from the ironworks that were providing the ordinary structural steel) create intricate balcony brackets. Fantastic results using, literally, iron age technology.


*For those of us who grew up on Warner Brothers cartoons, anvils are fun. Particularly anvils made by the Acme corporation.

Engineering Rainwater

June 29, 2016

New York City has combined sewers mostly because when our sewer system was started in the mid-1800s, no one had yet come up with a reason to separate clean water and “black water.” This occasionally causes trouble during heavy rains, when a literal flood of water can overwhelm the sewers. New buildings are designed to temporarily […]

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Some Links

June 28, 2016

The website behind-the-scenes revamp continues. I’d like to share a few links to reading that I found interesting: The 1939 New York Worlds’s Fair: here. Three different but not competing views about what makes cities work: here, here, and here. New York from a drone: here.

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Radio Silence

June 27, 2016

No, I didn’t forget to post on Friday and I didn’t forget to get a post ready for today. Some of you may have noticed the changes to our website design. We very much liked the old design but after five years we realized that it needed a few tweaks. Our designer, Elizabeth Ennis revisited her 2011 work and […]

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On The Receiving End

June 23, 2016

Design in general is about finding ways to meet multiple goals with limited resources. As a structural engineer I have to think about material properties and performance, code requirements for stress and deflection, construction logistics, and the relative costs of different solutions, among other issues. Architects have it worse*, because they have to worry about […]

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Historic Non-Structural Detail: Claustrophobic

June 22, 2016

I was in an old elevator today: This is not an elevator in a private house, where a lot of the rules don’t apply. It’s in an old house converted to apartments. People grumble about code changes, but they typically improve on bad ideas (like coffin-sized elevators) that were allowed under old codes. After Local […]

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Historic Structural Detail: Smooth

June 21, 2016

Revisiting old debates can be a bizarre experience. Outcomes that we take for granted because the debate was over long before we were born are being argued as if the answers are unknown. That happens, of course, because the answers were not known at the time the debates were taking place. We benefit both from hindsight […]

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Rationalizing The Minimum Higher

June 20, 2016

It’s something of a cliché to note that engineers go through an apprenticeship, where we learn to apply the analysis and sign techniques we learned in college to real-life situations. Many of the differences between theory and practice are subtle, but I want to discuss an example that was as unsubtle as it gets. In 1987, […]

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When Is A Crack Both Serious and Negligible?

June 17, 2016

In our previous discussions of cracks, we neglected a rare but weird category: cracks that look terrible because they really do affect structure, but are completely unchanging. That crack monitor has been there, to the best of knowledge, for a little over fifteen years. Since it was installed, there has been effectively zero movement. The crack […]

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Defending Brutalism

June 16, 2016

What can you say about an often-hated architectural style, when even its name is misunderstood? (Brutalism is not the same thing as brutalism.) I took the pictures of the Orange County Government Center (below) three and half years ago, before the decision was made to greatly alter Paul Rudolph’s Brutalist office building. I’d seen pictures […]

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