Sunday, March 23, 2008

Minneapolis Bridge

A story today by the Assoicated Press contains dramatic pictures showing "slightly" (but visible) bent steel gusset plates on the Minneapolis bridge that failed.  But the Associated Press goes tsypically off tshe minstream media deep end on what this means by making much of the pretty meaningless point (stressing it at least twice) the the bent steel plates in the pohotographs were "amond the first points of failure" of the bridge--the Associated Press failing to etiher explain that this could be meanignless (where first "points of failure" were), or that there was an earlier, federal report that said that the ENTIRE support structure of steel plates was inadequate to support the bridge.

Despite the despicable Associated Press, it is not NECESSARILY significant that there were slightly bent plates at points "among the first" (talk about weasal words) to fail.  For example, remember that famous bridge where winds set up an harmonic frequency that tore the bridge apart?  It would make no difference if there were "bent" structures near the places which first failed.

Remember the official, federal investigation report on this bridge failure?  The gusset plates were blamed, of course, but NOT because specific plates failed at the "points of failure".  Rather, the bridge was evidently DESIGNED with inadequate support plates.

Does that mean that bent plates should have been a WARNING that the bridge was inadequately designed, and failing?  Maybe.  I am not enough of an engineer to know, although it is obviously a question that should be asked.  But it remains true that the individual bent plates were probably NOT the "problem"--whether at the "point of failure" or not.  The problem was--according to that earlier report--the inadquate design of the bridge putting too much pressure on the inadequate support plates.

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