Tom and all,
 
This link goes to several additional photos of the fallen towers -- http://www.wwva.com/cc-common/mainheadlines2.html?feed=119921&article=7439986.  The most interesting view to me is aerial.  If I didn't say it previously, I'm told the towers were erected in the late '30s.  This certainly pre-dated any 1950 and later ANSI standards.
 
Would winds estimated at over 70 mph near the surface and over 100 mph at the top of the 400-ft towers be sufficiently strong to bring towers of this type  with continued structural integrity down?  Would a fall-pattern seen from above suggest a domino-effect?  it doesn't look to me as though they fell against each other.
 
Interesting.  Back to "important" stuff.
 
Jim
 
Jim Weaver, K8JE, Director
ARRL Great Lakes Division
5065 Bethany Rd.
Mason, OH 45040; Tel. 513-459-1661
ARRL, The national organization for AMATEUR RADIO

From: Tom Frenaye [mailto:frenaye@pcnet.com]
Sent: Saturday, August 07, 2010 10:47 AM
To: arrl-odv
Cc: arrl-odv
Subject: [arrl-odv:19260] Re: Date: Fri, 06 Aug 2010 09:03:18 -0400

To follow up on Jim's comments, K3LR tells me those towers were built pre-1950 ANSI standards.

   Tom/7 MT

Sent from my iPad



-----Original Message-----
From: Jim Weaver K8JE <K8JE@ARRL.org>
To: 'Chris Imlay' <w3kd@aol.com>; 'arrl-odv' <arrl-odv@reflector.arrl.org>
Sent: Fri, Aug 6, 2010 4:56 pm
Subject: RE: [arrl-odv:19253] Re: Date: Fri, 06 Aug 2010 09:03:18 -0400

Chris,
 
Excellent point for concern.  I didn't include a comment that these towers were around 70 years old.  Properly designed, built and maintained, this fact should have little if any difference in keeping them standing.  Conversely, inadequately maintained could have resulted in them being weakened by corrosion.  Incidentally, the WLW radio tower that handled the station's 500 kW transmissions and that was built in the 1030's still stand gloriously about 1 1/2 miles from my QTH.  This tower literally rocks on a ball-to-ball pivot at its base and is held erect by several large guy wires.  It truly is properly maintained.
 

 

From: Chris Imlay [mailto:w3kd@aol.com]
Sent: Friday, August 06, 2010 9:04 AM
To: arrl-odv
Subject: [arrl-odv:19253] Re: Date: Fri, 06 Aug 2010 09:03:18 -0400

This makes me nervous, because a cornerstone of our argument about setbacks in antenna cases and ordinance negotiations are that towers typically fall within a narrow radius around the base of the tower; a small percentage of their height. These towers most certainly did not do that, but that may be due to the fact that it was a three-tower DA. Not sure.
 
And the towers were "windmill" type, too. Not a design that one would think would collapse near the base and fall laterally.
 

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