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To: Jewels1091

That’s what it looked like to me. Seemed a little lightly constructed to me.

Meanwhile,...the Brooklyn Bridge is still standing and looking great.

A walk over the Brooklyn Bridge is one of New York’s pleasures.


8 posted on 08/08/2007 3:37:28 PM PDT by garyhope (It's World War IV, right here, right now, courtesy of Islam.)
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To: garyhope

The essense of engineering is to build the structure with just enough more strength in it than the greatest stress that shall ever applied to it. Unfortunately, none of us are sufficiently prescient enough to realize that the greatest stresses are often in some manner or effect beyond what can be imagined.

The Brooklyn Bridge was vastly overengineered and overbuilt, when the sheer brute strength of massive steel was counted to stand up well enough to any stress known at the time. And given that the materials available at the time were in many ways inferior to the best available today, that strategy worked well.

But engineers work under the gun from the bean counters too, as seen in high-dollar manufacture and construction of some of the modern machinery of life. “Make it a little cheaper” is the mantra in any number of engineering firms, while trying to emphasize that the cheaper design equals or exceeds to original specifications. But not by too much.

Suppose, say, that someone endeavored to construct a bridge using carbon fibers. Light, strong, and relatively resistant to the woes of vibration, weathering and oxidation. But an absolute bear to fabricate, and with the intricacies of design that are part of a bridge design, probably so prohibitively expensive to scale up that it would not get beyond model construction stage.

The fact is, that the design flaws in a highly engineered structure may not show for YEARS, or even never, if the excessive stress just never takes place. The design flaw of the World Trade Center, for example, was that when its internal steel supporting structure is heated above a certain temperature, it would collapse down upon itself. And this was because of a circumstance that nobody had imagined, that the burst tanks of a nearly fully fueled up jetliner would support a hot enough flame to cause the vertical members of the framework to be heated to the point where the steel became plastic and unable to support the weight of the floors above. The original design of the WTC allowed for the fact that a simple impact of the structure by an airliner traveling at 400 MPH could be absorbed by the building’s design, without compromising the integrity of the structure. But it did not allow for a subsequent fire in which temperatures would reach 2,700 degrees, causing the collapse.

The explosion that occurred in the basement of the WTC in 1993, while it caused a considerable amount of damage in the immediate vicinity, proved the original design concept was correct. The stress applied did not exceed the design limits. Conclusion, the engineers had built well. And the structure was still a splendid example of design superiority as of September 10, 2001.


40 posted on 08/08/2007 4:28:45 PM PDT by alloysteel (Never attribute to ignorance that which is adequately explained by stupidity.)
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To: garyhope

The Brooklyn bridge is a marvel. After reading “The Great Bridge”, I’m twice as impressed.


42 posted on 08/08/2007 4:32:26 PM PDT by Tijeras_Slim
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To: garyhope

You mean that one built for horse and buggy? LOL :)


51 posted on 08/08/2007 6:46:51 PM PDT by Snoopers-868th
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