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Re: [TowerTalk] Mast wind loading

To: "Doug Renwick" <>, <>,"Jim Lux" <>
Subject: Re: [TowerTalk] Mast wind loading
From: "Bill" <>
Date: Wed, 29 Mar 2006 09:33:15 -0800
List-post: <>
I guess I see it partly the same and partly differently Jim.

Risk analysis incorporates more than just the person building the tower, 
which is why the manufacturers specify the limits of their designs.  They 
have greater risk than the individual builder because they have the "product 
liability."  In order to recover from then you only need to prove that the 
product was defective in terms of materials, design or warnings.  If it was 
not you probably won't be able to clollect from them particularly if you 
violate their warnings.

The property owner has two kinds of liability based on negligence.  The 
first is the liability of the landowner and to persons on his land.  The 
extent of the liability (and the nature of the duty) depends on the "status" 
person injured as an "invitee," "licensee" or "trespasser."  The second is 
the duty to others not to injure them due to negligence whether or not they 
are on your land.

Violation of the building codes is probably "negligence per se" in most 
states which means the plaintiff does not have much to do to prove that the 
tower builder was negligent.  Deviation from the design standards is also 
evidence of negligence.  So the risk taker is putting his or her personal 
assets on the line when they take that risk.

There is one more class of persons who are risk takers.  They are the ones 
who recommend that someone else deviate from the standards.

It is not the manufacturer who will be held liable when something happens. 
It is the landowner and everyone who participated with him in his or her 
negligence.  Moreover, it is simply not true that it takes "destructive 
testing" to prove an installation.  Structural engineering knowledge is very 
much up to the task without destructive testing even though some of the 
empirical data may have originally come for such testing.  Determining the 
load limits of a particular installation is not rocket science and could be 
done by any experienced engineer.  Violating the load factors and safety 
factors determined by the engineers is more than just risky. It could even 
involve criminal liability in the worst cases.

So it is true that it is very informative to hear what others have done 
successfully.  But I would be more interested in hearing what has happened 
when it was done wrong, particularly where the builder got sued or had 
criminal charges brought against him..

----- Original Message ----- 
From: "Jim Lux" <>
To: "Doug Renwick" <>; <>
Sent: Wednesday, March 29, 2006 7:27 AM
Subject: Re: [TowerTalk] Mast wind loading

> At 03:20 PM 3/28/2006, Doug Renwick wrote:
>>You are to be commended for sharing your experiences and I
>>agree with your philosophy.  A lot don't share their
>>experiences because they get chastised by people who throw
>>around words like 'unsafe'.  Have these people ever heard of
>>'risk analysis'? much will your tower
>>withstand can only be determined by 'product testing to
>>destruction'.  If your tower arrangement has survived for 25
>>years then IMO you have a safe installation.  Great job!
> Well.. there's really two aspects to these kinds of things..
> The first is your personal risk acceptance posture.  If a tower or antenna
> failure affects only you,  you get to get decide how strong or rickety you
> want to make things.  In this context, all the manufacturers'
> recommendations, and various and sundry engineering discussions here and
> elsewhere, basically go to make you an "informed risk taker", but
> ultimately, you get to make the decision.
> The second aspect, and one that is sadly becoming more important, is the
> increasing regulatory environment, and the assumption of the 
> responsibility
> for failure by others (e.g. a city, your insurance company, etc.)  30 
> years
> ago, I'll bet nobody ever asked for wet stamped drawings for a amateur
> tower. You went out, dug the hole, put up the tower, and were done with 
> it.
> Certainly, that's what my friends and family did.  These days, though, you
> have to get a building permit, and that might require engineering 
> analyses,
> etc.  Granted, in some cases, this is an attempt to get rid of
> aesthetically offensive towers by burying them in paperwork and attached
> fees for officials to review and comment upon that paperwork.  However, 
> the
> regulatory burden has increased in many, many other areas, aside from
> antennas(see below).   In this application, you're asking someone else to
> take responsibility (i.e. the city that issues the building permit, the
> engineer who signs the plans, the insurance company covering the
> installation).  This naturally leads to a bit more conservatism.  The
> question has changed from "will the antenna and tower probably stay up" to
> "Can you guarantee, with your life's savings, or the city's budget, that
> the antenna and tower will not fall down?"  Remember also, the cost of the
> increased regulation falls on YOU, the consumer, not on the insurance
> company who asks for more analysis (it actually reduces their exposure),
> not on the city (which is now "safer", and has even increased their budget
> with user review fees), so there's a HUGE incentive to ask for analysis 
> and
> demand conservatism.
> As a licensed engineer myself, I use a VERY different standard on what I 
> do
> for myself than what I use professionally, and both are different than 
> what
> I might advise my friends to do over the lunch table.  And, even in my
> professional life, the level of analysis and margins might depend on a 
> risk
> analysis and an acceptance of potential failure consequences.
> (on regulatory burden increases) It's not all due to "blood sucking, 
> bottom
> feeding plaintiff lawyers", as much as some would like to believe it.  I
> think it's more due to a "tragedy of the commons" type situation, where 
> the
> lack of regulation prompts a few people to really push the limits (in the
> interest of improving their financial bottom line), leading to an 
> egregious
> event, followed by calls that "something MUST be done to prevent this
> horrible thing from ever happening again".  I'd say it's more a function 
> of
> the emphasis on monetizing everything, and being a "good citizen" costs
> money, reducing the bottom line.  I'd (cynically) blame the B-schools for
> encouraging analysis in terms of cost/benefit with all aspects reduced to
> some dollar value, that can then be tradedoff.
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