Cast Iron

Expounding on a Neat Trick

by Don Friedman on 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, supported by the side walls and two interior walls in line with the two columns on the facade we’re looking at. 

Both street facades are supported on these cast-iron arches tied with wrought-iron rods, and the arches are supported on cast-iron columns. The fascias at the tops of the old storefronts, which probably carried signs for the stores, hid everything from the rods up to the top of the brick band above the arches. I happened to be in the right place, at the right time, with a camera in my hand to get a series of pictures that show the structure exposed. 



It’s not an accident that the arches are so shallow. First, it’s easier to transition from iron to brick if the arch curve is shallow. Second, it was easier to cast the nearly-straight arch pieces than it would have been to cast more curved pieces. Most importantly, the shallower an arch is, the greater its horizontal  thrust, but the use of the wrought-iron ties meant that thrust was not a problem here. 

As I said before, this is a clever detail that uses the commonly-available technology of the era to do something quite difficult: support a masonry wall over a large void. 

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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Weathering Metals

August 9, 2017

Beautiful, right? Thanks to some old alteration work, we get to see the results of a nice little experiment in exposing metals to water. You’re looking at three beams here: a modern steel beam that had been directly supporting a sidewalk (middle left, outlined in purple below), the original cast-iron girder that supports that beam […]

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Historic Structural Detail: Assembly Required

March 22, 2017

It’s been a while since I’ve done one of these posts, possibly because my attention has wandered to more fertile fields of criticism. In any case, the picture above is a nice illustration of just how much cast-iron facades were kits to be assembled. (Note that there’s some flash burn on the left side of the […]

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156 Years Of Dirt

March 16, 2017

Whatever that light-gray dust is – some combination of rotted wood, ancient coal smoke, and pigeon crap, most likely – it was damned difficult to wash off my hands and shirt. But that’s not the point. What is this thing? It’s the cast-iron arch holding up the rear wall of an 1861 loft building over the […]

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A Century Passes

March 3, 2017

That’s the west side of Union Square, between 14th and 15th Streets, a little over one hundred years ago. It’s worth the effort to click on it to look at the bigger version. Personally, I love the facade signage. The building on the far left, partially cut off, is 1 Union Square West and it’s […]

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Investigation The Very Easy Way

February 8, 2017

That looks familiar. Where have I seen that before? Oh, yeah: it’s a double-beam seat on a cast-iron column:  

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