( … See also the Iraq war costs-ticker:)
A Metallurgist’s Insights: Published on Countercurrents.org, by Joel S. Hirschhorn, 02 August, 2007.
2 excerpts: … My career started as a metallurgist, than I obtained a Ph.D. in Materials Engineering and became a full professor of metallurgical engineering at the University of Wisconsin, Madison where I taught about mechanical metallurgy and failure analysis, and in my consulting practice regularly worked on explaining actual failures of products and systems …
… The Minneapolis bridge collapse happened during evening rush hour because that was a period of maximum stress, and that would be the trigger for expanding existing fatigue cracks. Once fatigue cracks get to critical sizes they grow and propagate very rapidly, producing powerful loads and stresses on remaining steel components and creating what appears to be a virtually instantaneous bridge collapse.
The remaining public policy question is clear: Will the nation spend what is necessary? Seven other major bridge collapses in the last 40 years have not done the trick. Inadequate bridge inspection has been a frequent documented problem, as well as some design defects. Many people have already died from bridge failures. But still the nation’s elected officials have not bitten the bullet and agreed to spend trillions of dollars over several decades to bring America’s physical infrastructure up to the most modern standards … (full text).
(He can be reached at DELUSIONAL DEMOCRACY).