[TowerTalk] Fwd: Fwd: Guyed + self supporting /2 ??

[Hans Hammarquist via TowerTalk]

Rich,


I used/use falling derrick when I install tower both for field-days and when installing the permanent tower I have at home.


Beside using an A-frame type derrick I am using four guy wires equally distributed around the towers. I would not install tower with only three wires as that can lead to stability problems during the raising of the tower.


With four guy wires you can keep the two on the sides in tension. The guy wire on the opposite side of the winch should be adjusted just to go into tension at the "flipping point". Then you have no problems with violent events even for a single operator.


Best 73 de,


Hans - N2JFS



-----Original Message-----
From: Richard (Rick) Karlquist <richard at karlquist.com>
To: Hans Hammarquist <hanslg at aol.com>; towertalk <towertalk at contesting.com>
Sent: Sat, Oct 18, 2014 12:05 pm
Subject: Re: [TowerTalk] Fwd:  Guyed + self supporting /2 ??


An additional consideration in tilting up a
tower in one piece is how much guying is needed.
While Rohn 25 can be tilted up, it typically
requires multiple levels of guying just to be
tilted up.  This is without any consideration
of wind.  This in turn rules out a simple gin
pole or crane and requires a falling derrick, which
pulls on both the upper and lower guys.  A
lighter weight tower with greater strength
such as an aluminum self supporting type can
be tilted with a simple gin pole using one
lift point.  Additional levels of guying for
wind purposes can still be used after erection
is complete.  Falling derricks have their place,
but are definitely more complicated, and are
harder to control because of the tipping point
phenomenon.  You essentially need dueling winches
to get through the tipping point.  If anyone
has solved this problem, please let us know.

Rick N6RK