[TowerTalk] Pipe Mast

[Frank T. Brady]

Friends,

 I'm sending this reply to the list in order to be sure I didn't miss
expressing my gratitude to all of the hams who have helped prevent me from
doing a dangerously ignorant project.  I also want to reach and thank a
couple of hams whose reply addresses don't seem to work - and I thought it
appropriate to clear up some misconceptions I caused with my original post.

 All but one of the replies I've had have been negative.  I think the main
concern was about my closing remarks about whether or not pipes could be
coupled together as a mast. Obviously, in retrospect, that was nonsense.

 However, the main point of my post was whether or not I can make a flagpole
whose base can serve as an anchor for one of my two 61ft wire antenna
support masts.  I will definitely put safety ahead of cosmetics, but I don't
see why both can't be served.  When I was corresponding privately with one
list member, he seemed to agree with my plan to anchor the guys 6 or 7 feet
above the ground at the top of 3" schedule 40 pipes buried in concrete. His
description of the forces involved seemed to indicate that I was properly
"over engineering" it with my pipe anchors.

He wrote (in part):
"Just for illustration, a 60 foot 2-inch mast has a wind load of 6.7 sq.ft.
At 70 MPH, the wind force on the mast is 134 pounds. So anything with a safe
working load higher than that will work okay. And don't forget you'll be
dividing that force by the number of guy wire sets/levels."

 So, thought I, my only remaining problem is to talk my wife into accepting
the one guy anchor pipe that has to be smack in the middle of the front
yard. The only 'disguise' we could both agree on was a flagpole.

 Now, could the front yard anchor pipe can be made strong enough to also
support a 14 or 15 foot pipe/tubing extension that would carry a flag safely
(total height of about 20 feet)?

 That is the question I need to answer.  Many of the replies have sounded as
though they thought I was going to be anchoring the guys of a large ham
tower to the pipes.  I was talking about somewhere between 100 and 200
pounds of wind load (distributed among the 7 tiers of 3 guys per tier).  The
replies sounded like I would be dealing with *much* more.

 Please forgive and forget my silly afterthought of using galvanized pipe as
a mast - how about the flagpole/anchor pipe?  I don't have to use galvanized
pipe, and I'm DEFINITELY not going to use couplings - but I don't want to go
bust on this one anchor point and I don't know what material to start
pricing after this great 'shootdown.'

 Just thought I'd update you guys on the the issue and thank all of you for
the MANY thoughtful (and possible life-saving) replies!

Thanks to all of you AND to the organizers of this incredible list,

 Frank T. Brady - W0ECS
 Wildomar, CA





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