February 2018

Different Issues Physically Close To One Another

by Don Friedman on February 28, 2018


Everyone sees the hole in the beam web, right? I mean, the rust ate straight through the web, creating that big irregular hole on the right. It would be rude to not acknowledge all that hard work on the part of oxidation. The brick covering the beam has been removed and there’s the hole for all to see.

There are more interesting things going on here. For instance, the six square nuts represent the back side of a beam to girder connection, with a roof beam running off away from us, inside the building. These are low-strength bolts – referred to in the distance past when I took steel design in school as “unfinished bolts” – and the relatively cheap steel is not faring well. The pattern of damage on the nuts and protruding bolt ends – with cylindrical delamination of rust surrounding each bolt is sometimes referred to as a “rosebud” rust pattern. As long as the shaft of the bolt bearing on the visible beam web is intact, the connection still works, but it’s loosened up a lot from when it was built.

Both the top and bottom flanges are rusted, which is no surprise given the condition of the web. That rust is a lot harder to see, because it’s trapped between the body of the beam and the masonry above and below, but is arguably more dangerous in the long run. A hole in the web won’t cause the beam to fail unless it’s quite big, but losing material off the flanges greatly reduces the beam’s carrying capacity.

My favorite issue here is not related to weathering. There’s an empty bolt hole just to the left of the middle bolt in the right-hand column of three. Given its location, it never had a bolt in it. Rather, that hole is a mistake on the part of the steel fabricator, some 110 years ago. My guess – and this is purely a guess – is that it was meant to be the first hole of the six needed for the beam connection, and the fellow drilling or punching the holes decided to double-check his dimension after he made the first hole rather than before. Fortunately, the presence of that hole does not significantly weaken the connection.

Building Nature

February 27, 2018

Yesterday’s post about the possibility of creating a park in the New Jersey Meadowlands didn’t touch on an interesting aspect of the proposed park: little of it would be built by people. Instead the park would be made by removing built structures and letting nature have its way. It’s easy to forget that most urban […]

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Adaptation as a Strategy

February 26, 2018

This article by Karrie Jacobs – What if New Jersey’s Meadowlands were a national park? – speaks for itself,  but I thought I might add a little context for people unfamiliar with the geography. People have heard of “the meadowlands” because of a football stadium located there but don’t necessarily understand what it is. Most of […]

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Site Visits Require Fast Decisions

February 24, 2018
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What Made It Possible

February 24, 2018

That’s the frame of the Dime Savings Bank in Detroit, visible during construction. Biggerer here.

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Freshness Elsewhere

February 23, 2018

The change in both perception and physical reality caused by skyscrapers (that I’ve been talking about) was, of course, not limited to any one location. The picture above (high-resolution here) is Court Square in Memphis in 1906. The square appears to be a pleasant small park, surrounded by buildings with a fairly consistent four- and […]

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More Freshness

February 22, 2018

To continue yesterday’s train of thought, here’s the Chrysler Building in 1930, roughly a year after completion. Again, if you want a very high-resolution copy, click here. We’re looking northwest to the Chrysler, at 42nd Street and Lexington Avenue. The tall, vertically-striped building on the right is the Daily News building at 42nd and Second; […]

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Looking With Fresh Eyes

February 21, 2018

That’s the Singer Tower as seen from Liberty Street, just east of Nassau Street, in 1910. If you’d like to download a ridiculously high-resolution copy, click here and wait a while. This picture emphasizes something that’s easy to forget in 2018, and that’s how alien the early skyscrapers were compared to the cityscape around them. […]

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The Details of a Technological System

February 20, 2018

This is an underside view of the heel connection of a heavy timber truss. The piece of wood at the top of the picture is the bottom chord, roughly 12 inches by 12 inches in section, and you can’t see the top chord above it. The bolt ties the two chords together, but the real […]

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