[TowerTalk] Tower guy line Anchor Positions

[Lux, Jim]

On 1/23/21 9:54 AM, Grant Saviers wrote:
> I agree with Scott. Not an expert, but likely took the same statics 
> course.
>
> The total tension in each guy varies according to its angle with the 
> tower in order to make the horizontal tensions the same.  If they 
> (horizontal) are then a tower should be plumb or something else is 
> happening.
>
> A limiting factor in decreasing the angle is to not exceed the total 
> vertical load rating = dead loads plus vertical tension component of 
> all guys plus wind load converted to vertical by the guys 
> (approximately speaking since the real stress calcs are more involved).

Here, though, KB8NNN is moving the anchor *away* so he'll need to reduce 
the tension in that one, and that will reduce the vertical load - which 
is a *good* thing.



>
> Another choice to avoid a driveway or to mow under is a elevated post 
> tie off for the guy that achieves the same angle with the tower for 
> all guys.  It does need to be buried plus dead weight or back guyed to 
> resist the overturning moment.  Plus strong enough. More than statics 
> 101 needed.
>
> Grant KZ1W
>
>
> On 1/23/2021 09:14, K9MA wrote:
>> Keep in mind that, unless the tower is very stiff, the horizontal 
>> component of the tension in all the guy wires will be equal. That 
>> means that if the anchor points are not equidistant from the tower, 
>> the total tension in the guy wires will not be equal. The greatest 
>> tension with be in the guy wire anchored closest to the tower. That 
>> suggests that the tension in that guy wire should be the usual 10 
>> percent or so of breaking strength, and let the others fall where 
>> they may, as long as the tower is plumb.
>>
>> This is all from Statics 101 many years ago and simple trigonometry. 
>> The real tower experts on this list may disagree, and I'd defer to them.
>>
>> 73,
>> Scott K9MA
>>
>> On 1/23/2021 8:34 AM, R. David Eagle via TowerTalk wrote:
>>> Hello,
>>> I am considering putting up my Glen Martin Tower with Hazer that I 
>>> purchased from an estate a couple years ago and after careful 
>>> measurements and drawing everything out, I have noticed that I may 
>>> have to extend an anchor point out a little to clear a parking 
>>> area.  Now, this is only a 40' tower....So how critical is it that 
>>> ALL anchors be distanced from the base equally?  OR just maintain 
>>> tensions?  Good ol physics.
>>> Any help would be appreciated...
>>> Thanks,
>>> DaveKB8NNU
>>> _______________________________________________
>>>
>>>
>>>
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>>
>>
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