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Re: [TowerTalk] More crank-up questions

To: towertalk@contesting.com
Subject: Re: [TowerTalk] More crank-up questions
From: Jim Lux <jimlux@earthlink.net>
Date: Sun, 01 Dec 2013 09:49:01 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 12/1/13 7:55 AM, Ken wrote:
I am curious.  All this talk about concrete strength, rebar, etc.
Is anyone aware of a tower base failure due to strength of the
concrete or lack of rebar?  (Except for damage from a lightning
strike.)  From what I hear, the vast majority of tower failures are
20-30' above the base.  Base failures? Are they really an issue?

I think it's more that there are a whole lot of towers out there, and there's no systematic reporting of failures. Everything is anecdote.

You generally don't hear about foundation failures in houses either, unless there's some sort of litigation on a large scale (e.g. an entire tract that has foundations without rebar).


As I mentioned, 40 years ago, little was said about base concrete,
rebar, etc.   OTOH, 40 years ago, 60' was a big tower.  Maybe that's
part of the issue.

Everything in the building trades has gotten more rigorous. Engineering has gotten better, expectations of city building departments have gone up.

Look at all the changes for seismic and wind related design. 40 years ago, bolting the house to the foundation wasn't standard practice, and there's plenty of "soft first story" buildings in Los Angeles that would never be built today.


There is another scary aspect to this attention. So far, municipalities tried to regulate towers out of existence because of aesthetic concerns. PRB-1 did away with that. However, a potentially more effective approach to do away with towers is to start raising safety issues.

How many hams in suburban areas with 100x100 ft lots could *prove* that their tower, should it fail, would fall entirely within their lot and not cause any damage to the house?

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