Engineering

Sometimes An Ugly Duckling Becomes An Ugly Duck

by Don Friedman on March 22, 2018


For a long time, most of New York’s waterfront was industrial. Some still is: that’s Long Island City in the picture above, a stone’s throw from the East River but somehow ungentrified. In the background on the right is the Queensboro Bridge. It’s a cantilever truss with three unequal spans: over the east channel of the river, Roosevelt Island, and the west channel of the river. It also has some identity issues, being named at various times the Queensboro Bridge, the Welfare Island Bridge (after an old name for Roosevelt Island), the Blackwell’s Island Bridge (after a very old name for Roosevelt Island), the 59th Street Bridge, and the Edward I. Koch Bridge.

New York is a city of long-span suspension bridges, and it’s hard for a cantilever truss to complete on looks. A truly beautiful cantilever truss, like the Forth Bridge, can hold its own against any competition, but the Queensboro is not truly beautiful. It’s asymmetrical (the slope of the end spans is different because of different elevations of land in Manhattan and Queens, and the length of the two channel spans is different) and it’s a very heavy design in part because it originally carried a roadway, trains, and trolleys. Compare to the Brooklyn and Manhattan Bridges downstream, or the Verrazano Narrows, it’s ungainly and visually heavy.



Seen from the upper-deck roadway, it feels almost like a tunnel with windows, which is especially ironic as F. Scott Fitzgerald wrote a poetic description of the view from it.



The most damning description came from a man who helped design it. The structure of the bridge was design by a team led by Gustav Lindenthal. As the directions of forces in a truss like this are typically known, he was able to distinguish tension from compression members for efficiency: the tension members are ganged eyebars, while the compression members are built-up laced boxes. The architect Henry Hornbostel was brought into the design to civilize it architecturally; as far as I know he’s responsible for the ornamental pinnacles on the towers and some trim on the end portals, and that’s about it. Hornbostel has been widely quoted as saying, upon seeing the completed bridge “My God, it’s a blacksmith’s shop!” Over a hundred years later, I’m not sure there’s anything else to add.

Book Review: Built

March 12, 2018

Roma Agrawal is an engineer based in Britain with an impressive resume. Her design experience is quite varied, but to some degree dominated by her work on the Shard. She has written the recently-published Built, which is perhaps best described as a primer on civil engineering and civil engineers for the vast majority of people who […]

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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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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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Another Branch of Engineering

February 18, 2018

An absolutely fantastic piece in the New Yorker: Why Paper Jams Persist. I’m no more familiar with the mechanical engineering analysis and design of printers than any other person who’s had to clear a paper jam, but I still hung on every word. Design is all about balancing different constraints. Those we deal with are […]

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Not a Skyscraper

February 11, 2018

The 277-foot-high Brooklyn tower of the Brooklyn Bridge in 1877, with the temporary walkway slung over its top.

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Fiction

February 9, 2018

I’ve been reading Designing Culture by Anne Balsamo, which is largely a sociological study of how engineering affects everyone around it. It’s interesting, if a bit off from my usual reading. One sentence in it grabbed my attention: Balsamo refers to a famous book in the same field, Aramis, or The Love of Technology, and […]

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Physical Reality Governs

January 30, 2018

Structural engineering is pretty much the reverse of the high-tech virtual world that is hyped in the press as “technology.” Whatever computerized tools we use in design, our work is grounded, literally, in the physical world and its constraints. This article and its linked source are fascinating in the way they reveal the lack of […]

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A Review of a Review

January 28, 2018

The Happy Pontist certainly makes History of the Modern Suspension Bridge by Tadaki Kawada sound like a great read. Another book on my todo list…

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Building Within The Context

January 25, 2018

Curbed was nice enough to map the tallest buildings in New York: existing, in construction, and planned. Given that the tallest spire is 1776 feet and the highest roof is 1550 feet, and the Burj Khalifa is 2722 feet high, we’re talking about the tallest in NYC and competitive within the USA, not internationally. It […]

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