Decrepit Old Fool

“For a successful technology, reality must take precedence over public relations, for nature cannot be fooled.”
- Richard Feynman

For some weird reason, manmade disasters are an avocation of mine.  I have two or three dozen books on various disasters ranging from the Johnstown flood to the Tenerife disaster, along with books on structural engineering, fracture mechanics, corrosion properties of metal, and related weather and geology.  The science and tech magazines I take often feature detailed disaster articles that I pore over the way some people read sports scores.  And of course, I’ve studied that other famous disaster, which I will NOT be mentioning here because I don’t want to get side-tracked on people’s whacky conspiracy theories

News reports, of course, focus on “human interest stories”, which dribble on endlessly about how people were scared, and are sad and upset, and that stuff is of little interest to me except for the sociology of disaster response or the technology of rescue.  The human-interest story that interests me is the one that took place before the disaster, and is just as important as, and often the indirect cause of, the corrosion fractures, etc.

Here’s an unlinked summary of what I’ve been able to find out so far (You can use Google as well as I can).  There’s a fair amount of “Duh!” in the mix:

• The bridge had been found corroded and cracked, structurally deficient, as far back as 1990. A plan to reinforce cracked welds and rusted bolts was deemed prohibitively expensive.

•   There are 77,000 bridges in the US in the ‘structurally deficient’ category, though Congress acting boldly in response to the disaster just earmarked $250m to rebuild this one.  In other news, this seems like a good spot to quote Mark Twain: “Suppose I were a congressman.  And suppose I were an idiot.  But I repeat myself.”
• A plan to monitor its health electronically was dismissed in favor of routine inspections.  Apparently the bridge was designed without a redundant load-path to ground, so huge numbers of individual sensors would have been required.  Modern bridges are designed with redundant load paths, or at least they’re supposed to be.
• The bridge was receiving a routine resurfacing with some very heavy road equipment at the time of the collapse.
• Cell phone networks get overloaded when disasters happen.
• Governor Pawlenty rejected an extra gas tax that would have funded better highway maintenance in his state, but now he’s reconsidering.

This story appears headed in an all-too-common direction, of politicians gambling with people’s lives while making themselves look like heroic tax-cutters.  (Of course, there’s always tax money for stadiums)

I’ll write about this in more detail when better information comes in.  If you’re interested in the “human-interest” stories, just turn on the television.  It’s pretty much wall-to-wall there with little information about the actual bridge or the political backstory. 

UPDATES:

• In the context of this bridge collapse, Cajun reflects on the essential difference between engineers and politicians.

• Michael O’Hare On engineering bridges
• Math entrepreneur Stephen Wolfram has a design idea for new bridges using cellular automata – bridge designs generated by algorithm rather than designed by engineers.
• Sensors are getting cheaper so it may be possible to equip bridges that would continuously watch the health of the bridge.