"Gavin Staples" wrote in message



"Joe Egginton" wrote in message
...
Ferrybridge cooling towers collapse 1965 caused by severe wind loading at:
http://www.cen.bris.ac.uk/civil/staf...errybridge.htm
I saw a documentary on this many years ago. The
fact that it was well documented led to an enormous amount of knowledge
acquired with regard to strong winds on all structures. It was lucky in
this case that no one was killed or injured.

The film of it is shown regularly on the OU in the wee smalls, along
with that bridge in the USA and windtunnel models of an aircraft.

Its all about turbulence, notice how a 4 engined airliner produces 2
contrails. The votices hold it up contra-rotating.... blah blah blah...

I always find it amazing that the towers could flex the way they did. I
presume, had they been made of brick, the bricks would have fallen out
of line thus breaking up the shape and foiling the harmonic.

I wonder what the audible frequency was.

Ever since then towers have a spiral built around them, this allows wind
to pour off the sheltered side giving a streamline.



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