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
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|