Depends on the design of the crank-up tower...
The Tri-EX CT-100 is a 100ft guyed crank-up tower. see
http://www.qrz.com/db/WA3GIN for pics.
You have to identify the manufacturer of the tower to determine if the tower
was designed to be guyed or to be free-standing. Usually, its pretty easy
to make the determination as a guyed crank-up will often have guy
attachments loops welded to the top of each tower sections, as well as a
tower load-lock-out that removes the vertical compression concern that Steve
mentions from the lift cable.
Good Luck, Be Safe, and Have Fun,
dave
wa3gin
----- Original Message -----
From: "Steve Jones" <n6sj@earthlink.net>
To: "'Gary and Arlene Johnson'" <qltfnish@omniglobal.net>;
<towertalk@contesting.com>
Sent: Thursday, March 07, 2013 2:59 PM
Subject: Re: [TowerTalk] Crank Up Tower Info
You should not guy a crank-up tower. The guys turn lateral wind pressure
into a vertical compression force pushing straight down on the raising
cable. On a regular guyed tower, ie. Rohn 45, the whole tower structure
is
designed to resist that downward force. On a crank-up, only the raising
cable is resisting that force. There is certainly some design margin in
the
raising cable strength that would let you get away with guys up to a point
if you want to take the risk.
73,
Steve
N6SJ
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
Gary
and Arlene Johnson
Sent: Thursday, March 07, 2013 11:39 AM
To: towertalk@contesting.com
Subject: [TowerTalk] Crank Up Tower Info
I have an unknown brand of crank up tower that I need to put up. The tower
can go up as high as approx 72 feet if all 4 sections are used. I plan to
only use the bottom 3 sections as did the guy I got it from. The guy I
got
it from had it guyed at the 20 foot and 38 foot levels (at the top of the
bottom and middle 20 foot sections). For a tower of this height how far
from the base do I install my ground anchors?? Would I put them at an
average of the distance between the two sets of guy lines (approx 29-30
feet) or at the distance of the upper guy line (38 feet). When he had the
tower fully retracted he just let the upper guy lines go slack. The
alternative to this question is should I put in a set of ground anchors
for
each set of guys??
Gary J
N5BAA
Hill Country Amateur Radio Club Secretary 2013 Kerrville, TX
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