Cast Iron

Design At Different Scales

by Don Friedman on February 1, 2018

Rain Noe gives a nice summary of cast-iron vault lights here: Urban Design Observation: Why SoHo Has 19th Century Glass Sidewalks and Stoops.

Noe is approaching vault lights from an industrial design perspective, which is obviously different from my background. The nice thing about design discussions is that one perspective isn’t necessarily more right than another: just because I see vault lights as elements in a large-scale building system doesn’t mean that a discussion of their industrial design is invalid.

Two related thoughts… First, Noe points out “Note the raised nubs at the interstices between the glass, which provide traction in rain.” Iron and glass are not exactly the best traction surfaces when wet, but those little bumps keep vault lights walkable in the rain. That’s much more the industrial design end of things than architecture or structure and worthy of note specifically because that lesson has still not been learned. It never fails to astonish me when paving materials are used that become slick when wet. Is rain a surprise?

Second, you can buy replacement lenses for your vault lights. For example, go here ( ) and scroll down to “Custom Pavers: Rounds used in sidewalk restorations.” So, these beautiful pieces of 150-year-old design can be kept functioning.

An Iron Appendix

January 16, 2018

That’s a photo of an areaway in London. The wall on the right is the building and I’m standing at the corner of the areaway. The black coping along the left is on top of the curb that’s an extension of the areaway’s outboard wall, extending above the sidewalk. If I had to guess, I’d […]

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You Can’t Not See It

January 3, 2018

There’s a fairly well-known phenomenon by which once you’re aware of something you start to see it all over. This isn’t the result of inanimate objects in the natural world conspiring against us but rather the result of sensitization. We can look at something for years and not see it because we don’t think about […]

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Analyzing a Historical Anecdote

December 18, 2017

That’s my close-up of the top of one of the fence posts at Bowling Green. (Yes, it is on my walk to work. Thanks for asking.) As you can see, the top of the post is quite rough. In one of the more famous acts of vandalism in New York history, the Sons of Liberty […]

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The Machine Aesthetic

December 1, 2017

In one sense, all building materials are artificial. Even the wood we use as lumber is shaped into geometries not seen in nature: rectangular in cross-section, straight, and identical from one piece to the next. But somehow metal seems artificial in a way that masonry and wood do not. You can see artists struggling with […]

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Expounding on a Neat Trick

October 30, 2017

I talked a bit about this type of detail recently but I was surprised to learn that I hadn’t posted these pictures. This is a middle-third of the 1800s tenement in Hell’s Kitchen that was built with retail space on the first floor. The wood joists of the floors and roof span left to right, […]

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Partially Hidden, A Neat Trick

October 26, 2017

I thought I had talked about this type of structure before, but maybe not. How do you create a storefront when it’s the 1840s or the 1860s? How do you support a masonry wall over a glass void? Affordable steel beams are decades away and wrought iron beams are untried and new technology. The answer […]

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Labor Day Weekend 1

September 2, 2017

Workers erecting cast-iron columns.

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Composite Structure

August 21, 2017

That’s the side wall and an oblique view of the front of a small building on Nassau Street. The front appears to be early twentieth century, but the odds are good that this is an older building that has been modified multiple times. If nothing else, the storefront – visible as sheet metal at the […]

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Sidewalk Vaults and True Obsolescence

August 14, 2017

For people unfamiliar with sidewalk vaults, the illustration above, from 1865, might seem plausible, but it’s actually Daniel Badger’s fantasy of how he could sell more iron. The left-hand side is reasonably accurate for mid-1800s vaults: the facade columns extend down past the plane of the sidewalk, marking the separation of the cellar proper from […]

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