Re: more cfrp bleating

jim beam wrote:
Peter Cole wrote:
jim beam wrote:
http://science.slashdot.org/science/07/09/20/1352208.shtml

fortunately, the slashdot crowd is a little more analytical.

http://science.slashdot.org/comments.pl?sid=303589&threshold=1&commentsort=0&mode=thread&pid=20680345#20680839




Most of the slashdot comments were pretty random, not really addressing the concerns of the Dan Rather story.


For anyone interested in the actual letter that Vincent Weldon (ex-Boeing employee) sent to the FAA, it is here:

<http://seattletimes.nwsource.com/ABPub/2007/09/17/2003889769.pdf>

I found it to be a rather detailed and interesting description of the issues. Most of the concerns discussed (g-force transmission to passengers, lightning strikes, toxic combustion byproducts) have little relevance to the use of CF in bikes. His description of the fundamental characteristics of composites are pretty interesting in light of prior threads, though. Many of those are relevant to bikes.

I wouldn't dismiss this guy as a crank, although I think he could have a better spokesperson than Dan Rather.


who gives a damn about dan rather? /i/ posted it as a follow-up to carl fogel's story on the same subject. and it illustrates what happens when the uninformed and hysterical start bleating about subjects on which they have no knowledge, but an easily exploitable fear of what to them is the unknown.

Given that no commercial aircraft approaching this size has been built with a composite fuselage, it is an "unknown" to everyone.


as a further example, here in the bay area, we're building a new span to the bay bridge. one day during the most visible new construction phase, there was a sensational headline picked up in the local media about defective welds and "massive cover-up" on behalf of the contractor. source? disgruntled former worker that had been fired and who wanted to stir up trouble - and who knew enough technical jargon to cook up a credible sounding story to the uninitiated.

Er, it was 15 welders, actually.

It was recognized even at the time the story broke that welders aren't qualified to judge weld quality.

Caltrans had a major discovery of fraud covering up bad welds 10 years earlier.


and the media, being uninitiated, takes his story as sufficiently sensational to run with. the story died out after the "source"'s credentials and history were exposed, and after the contractors had wasted a bunch of time and money going back through their testing certification, but it's a "story" that would never have come to light if the media had done even basic background checking or bothered to speak with other engineers first.

Actually, it was the FBI who got the ball rolling. Their investigation had been going on for some months before the story broke.

A neighbor of mine is an FBI agent investigating similar issues with the "Big Dig" -- these things happen all the time and often turn up serious fraud.

and what do we have here? an identically disgruntled former employee with a mouthful of "credible" sounding doomsday warnings approaching an ignorant but sensation-seeking media looking to stir up trouble.

A 47-year Boeing employee, with serious credentials, apparently not alone with his concerns.

He specifically mentions the difference in yield strains between aluminum and CF composites and the effect that may have on shock absorption. He specifically uses the word "brittle".


and apparently succeeding if the ridiculous bleating on r.b.t is a gauge.

Nothing in common, actually. The Boeing engineer's primary charge is that the testing protocols are insufficient for the new technology.

still, as part of the old saying goes, "you can fool some people all of the time", and thus it is proved.

Nothing is "proved". You don't even have the facts straight.
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