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"Lighting Rep" <lightingassociates@xxxxxxxxx> wrote in message
news:1165380705.236078.193910@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
>
> Narasimham wrote:
>> Phil Carmody wrote:
>> > "Richard Henry" <pomerado@xxxxxxxxxxx> writes:
>> > > Narasimham wrote:
>> > >
>> > > > Sorry,it is not so as we gather.As Progenoskes also observed,Tacoma
>> > > > Narrows Bridge was a new physics/mechanics situation as a strange
>> > > > unsteady state aerodynamics phenomenon that had not been
>> > > > encountered in
>> > > > engineering situations up till that point of time...naturally not
>> > > > mathematically modeled to be handed down to practising design
>> > > > engineers.The failure analysis commitee also cleared them of any
>> > > > charges of negligence. Even in late nineties a Boeing aircraft
>> > > > empennage was destroyed at Japan Norita airport due to such
>> > > > causes.However the degree of goofitude in Hyatt Hotel is an order
>> > > > of
>> > > > magnitude higher.
>> > >
>> > > The Hyatt Hotel walkway was not built as designed, so it is hard to
>> > > fault the designer.
>> >
>> > Not built as *originally* designed. They changed the designs because
>> > they were not practical from the manufacturing standpoint. It was
>> > built in accordance with the new designs. Designers somewhere, and
>> > the people who reviewed and signed off those designs, are to blame.
>> >
>> > And you *can* fault the original designer too for designing something
>> > for which the components and construction were practically impossible.
>> >
>> > Phil
>> > --
>>
>> If you build 10 stories above the foundation, the foundation has to
>> take the weight of 10 stories in compression.If you hang 10 stories
>> down from the ceiling,the ceiling has to take the weight of 10 stories
>> in tension.What prevented adoption of floorwise tapering I-Beams or
>> welded taper tubes? It is the speed needing to ignore blind
>> spots.Granted things are more clear in hindsight.However insistence on
>> routine elementary but mandatory structural checks by a second party in
>>
>> large constructions e.g., by finite element analysis would have
>> routinely eliminated such loopholes when elemental modeling would be
>> considered.This is not maths but managerial practice of safety concern
>> in engineering. But"Safety does not sell."
>
>
> Ummm - Remember - Most everything, built, designed, engineered,...
> Is completed by the LOW bidder - You get what you pay for...
>
My father is a retired structural engineer and he knew, for instance,
someone who was killed in the Melbourne bridge disaster (box girders, I
believe) where the bridge collapsed whilst it was in construction.
There is the well-known Tay Bridge disaster where the bridge collapsed over
the river Tay with a train on it, shortly after it was completed.
But bridges don't get built by sitting on a sheet of paper or on the
computer.
There is also the French cathedral (possibly Beauvais) that collapsed in the
thirteenth century. The roof was bigger than any previous cathedral and if
the proof was in the pudding the pudding collapsed.
See
http://www.tech.plym.ac.uk/sme/FailureCases/List_Engineering_Successes_Failures.htm
Nick
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