Hello, Bill and all;
Dave Leeson's book, "Physical Properties of Yagi Antennas," shows how to
calculate wind forces and strength (bending and tensile) of all the
cylindrical members involved, including antennas, masts, and tower
members. It was recently available from Ham Radio Outlet and you may be
able to borrow a copy at a library. I haven't examined anything that
addresses wind force on stranded guys (they aren't the same as
cylinders), on the buckling strength of guyed towers (apply guys only in
accordance with correct engineering analysis), or on the properties of
earth since studying engineering over half a century ago.
Earth must be treated as a viscous fluid, or treated in very simple
approximations with plenty of assumptions on the safe side. For
ezample, assume no side resistance on the base of a self-supporting
tower; it stands because the total weight of the structure multiplied by
the minimum radius of the base exceeds the sum of wind forces multiplied
by the associated moment arms. It doesn't sink because it is
approzimately floated in earth.
Both these assumptions may be refined with detailed knowledge of soil
properties and mechanics, but only if the soil properties are measured.
I haven't delved into the properties of guy anchors. As Steve always
reminds us, follow the manufacturere's specifications or hire the
services of a licensed professional engineer, preferably one with good
insurance.
73 de WO?W
William H. O'Hara III wrote:
>Hello,
>
>I'm very interested in the discussion
>on the list. I would like to erect
>a tower in the eventuality. Does any
>one have a really GOOD primer for
>tower instruction, pictures of guy
>installation, diagrams, etc.? Is there
>a book available? I've tried a few
>web searches and some book searches
>with nothing to be found. I did not
>see an ARRL book on the subject,
>either.
>
>Additionally, is there anyone familiar
>with the rules for towers in my county
>or perhaps my town? I am aware that
>the wind speed is 95 mph. What are
>the requirements for towers for certain
>heights such as base width, concrete
>foundation, wind loadings, etc.
>
>Any help would be appreciated.
>
>Bill
>KB1IUB
>_______________________________________________
>
>See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless
>Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
>questions and ask for Sherman, W2FLA.
>
>_______________________________________________
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>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
>
>
>
>
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