I recommend following the manufacturer's plans and specifications
to the letter. To substantiate this advice, I offer the following
classic good news, bad news, "war" story from my days as
a trial lawyer:
The good news:
I worked a personal injury case with another lawyer, wherein
the Plaintiff claimed he was injured when a amateur radio tower
fell down and struck him (mostly in the head). The jury found
the tower manufacturer negligent in how it designed the way
one had to setup and install the tower - and awarded the Plaintiff
$1 Million in damages.
Hmmm... not bad, you say...
But wait... there's more! There is the bad news:
My state recognizes what is called "comparative negligence" -
and, accordingly, the Jury is instructed to reduce the total
damages awarded to a successful Plaintiff in direct proportion
to the degree it finds the Plaintiff was HIMSELF negligent in
causing his own injuries.
So... the Jury also found our Plaintiff 95% negligent in the
setup and installation of the tower, and, thus, the damage
award was reduced by the same percentage!
- - - -
MORAL OF THE STORY => If you want the manufacturer to be liable for
any and all injuries or losses sustained as a result of negligent or
unsafe design or manufacturer,... then be careful, and follow all
manufacturer instructions to the letter - lest YOU also be found
negligent in causing the loss.
And now you know why I will HIRE SOMEONE to erect MY TOWER this
summer. Experienced. Trained. Bonded. Insured. AND LIABLE.
I will be out of town.
Just my take. Your mileage may vary depending on circumstances,
state law, and amount of luck you might have.
///////////////// JR - K8JHR /////////////////
==============================================================
jim Jarvis wrote:
> Yes, you're right. I hadn't considered guying just the lower section.
>
> You could do that, but it wouldn't add capacity.
>
> I'm a fan of these tubular crankups, except for the fact that their
> ratings
> are relatively low. So long as you don't have to meet a 90mph wind
> rating,
> you can use them for small antennas.
>
> N2EA
>
>
>
>
> On May 7, 2008, at 10:32 PM, Jim Lux wrote:
>
>> jim Jarvis wrote:
>>> Ignoring, for the moment, the prime directive, let's look at
>>> what you're doing if you guy a crankup tower.
>>> The lateral forces on the tower, which cause it to flex and shed
>>> load, are transferred to
>>> the guys, and to the vertical structure itself. With a crankup,
>>> that means to the hoist cable!
>>> The cable is not specified for anything more than lifting the
>>> weight of the tube, with some
>>> safety margin.
>> Except if you just guy the bottom section. I'm assuming that the
>> lowest tube has plenty of compression strength. I'm not sure this
>> buys you much (I suppose you could get away with a smaller (or
>> almost no) base, since it doesn't have to take the overturning
>> moment)..
>>
>> I've seen this strategy used with things like tower trailers.
>> Solves the problem of keeping the whole thing reasonably upright,
>> without adding load to the hoist cable.
>>
>>
>>
>>
>> Jim, W6RMK
>
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>
>
>
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