Hi, Chris.

I understand from some knowledgable SoCal Contest Club members that most commercial crank-ups are designed with the top section as the weakest link, a "mechanical fuse", if you will, so that failure results in a restricted damage zone. I haven't confirmed this with any manufacturers but, if it is true, it would be a good counter-argument in case the issue is raised.

73,

Marty N6VI

----- Original Message -----

From: Chris Imlay

To: arrl-odv

Sent: Friday, August 06, 2010 6:03 AM

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.

73, Chris W3KD