In a message dated 7/10/2011 12:01:31 P.M. Pacific Daylight Time,
towertalk-request@contesting.com writes:
> In the process of replacing a 50 foot Rohn 25G with a 58 foot fold over
version. New base and guy wire anchors have been poured and the question
of
guy wire tension needs clarification. Neither one of my Rohn catalogs
mention anything specific regarding the tension for the 4 guy wire scheme vs.
the 3 found on conventional installs. I?m wondering if using the standard
formula of 10% tension will still be okay even with the extra guy wire.
Will
be using new 3/16 EHS and hardware and have a Loos PT-2 tension gauge. If
anyone out there knows of any mention of the proper tension with the
fold over kits, I?d certainly appreciate it.
Howdy --
Use the normal 10% tension on each guy. For a tower of this height, a
fourth guy isn't going to put any undue strain on the leg compression.
The 10% tension figure is a good safe working load (SWL - I was one
once). Any cable, rope, etc. has a SWL of between 10 and 20% of ultimate
breaking strength. For guys - too tight and you load the legs with added
compression; too loose and the tower will wind slam.
25G will go to 190' @ 90 MPH with adequate leg strength so 4 guys @
40' isn't putting much of a strain on it.
> Also, any owners with interesting ideas of lifting the boom assembly
would be valuable. My plan was to use my trusty tower assistant; Mr. ATV and
gin pole.
What ginpole? The Rohn ER2545 is only rated up to the 70 pounds of a
45G section so please be careful. You could also just attach a pulley to a
horizontal and use the tower for the ginpole.
Cheers,
Steve K7LXC
TOWER TECH -
Professional tower services for hams
Cell: 206-890-4188
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