I have 6 sections of Rohn 25 set in a yard of cement. It is guyed at about
30 feet and about 5 feet under the top of the tower with 3 wires at each
place. I need to remove the wires on one side so I can cut a tree to keep
it from falling on the guy wires.

On top of the tower is about 15 feet of pipe sticking out. About a foot
over the tower is a 3 element triband, and at about 5 feet spacing is a 5
element 6 meter antenna, two meter,and 432 antenna all on 15 feet long
booms.

Will it be safe to remove the two guy wires on one side of the tower for
about an hour to cut the trees, or should I let the tension off all the guy
wires ?
This would be done when the wind is not blowing.

"Ralph Mowery" wrote in
m:

I have 6 sections of Rohn 25 set in a yard of cement. It is guyed at
about 30 feet and about 5 feet under the top of the tower with 3 wires
at each place. I need to remove the wires on one side so I can cut a
tree to keep it from falling on the guy wires.

On top of the tower is about 15 feet of pipe sticking out. About a
foot over the tower is a 3 element triband, and at about 5 feet
spacing is a 5 element 6 meter antenna, two meter,and 432 antenna all
on 15 feet long booms.

Will it be safe to remove the two guy wires on one side of the tower
for about an hour to cut the trees, or should I let the tension off
all the guy wires ?
This would be done when the wind is not blowing.



As you have probably guessed, guy maintenance on towers is a high risk
activity. Lots of seriously large towers have failed because a single guy
was slackened. The taller the tower, the greater the risk.

In any circumstance, slackening (or removing) one guy of a set will
introduce a lateral force that bends the tower. With sufficient weight,
that may lead to buckling and structural failure.

If you remove all guys in a set by progressively slackening each them,
that may not introduce the lateral force describe above, but the greater
length between existing supports may allow buckling and structural
failure.

Can you remove all guys? Is the tower installation designed to be free
standing at reasonable wind velocity?

The safe answer is to consult a structural engineer.

Can you remove the tree without slackening guys and without risking
dropping parts of the tree on the guys? Perhaps cutting the tree into
smaller lengths that are lowered to the ground on ropes to guide and slow
the descent? I have watched tree climbers take huge trees down, lowering
all the pieces in a very limited space against the trunk.

Have you asked your arborist about the removal and the risk to the tower?

Owen

Just from what you've posted, your tower sounds sort of 'marginal' to
start with. I would be very careful in loosening any of those guys.
- 'Doc

"'Doc" wrote in message
...
Just from what you've posted, your tower sounds sort of 'marginal' to
start with. I would be very careful in loosening any of those guys.
- 'Doc


Unless I missed something when I described the tower, what is marginal ?
The first section of tower is set in a yard of cement as described in the
Rohn booklet. Also they only require two sets of guy wires up to 70 feet.
I live in the middle of North Carolina so a large build up of ice or very
high winds ( say over 90 mph) would be unusual.

On Thu, 20 Aug 2009 07:55:55 GMT, Owen Duffy wrote:

Perhaps cutting the tree into
smaller lengths that are lowered to the ground on ropes to guide and slow
the descent? I have watched tree climbers take huge trees down, lowering
all the pieces in a very limited space against the trunk.

Here in the Pacific Northwest, tree country, I have never seen any
other way except for when trees are layed over indiscriminately as
part of a clearing operation.

73's
Richard Clark, KB7QHC

Ralph Mowery wrote:
"'Doc" wrote in message
...
Just from what you've posted, your tower sounds sort of 'marginal' to
start with. I would be very careful in loosening any of those guys.
- 'Doc


Unless I missed something when I described the tower, what is marginal ?
The first section of tower is set in a yard of cement as described in the
Rohn booklet. Also they only require two sets of guy wires up to 70 feet.
I live in the middle of North Carolina so a large build up of ice or very
high winds ( say over 90 mph) would be unusual.


On the "internets", there is always someone for whom your tower setup is
not acceptable. Doesn't matter how well made and installed, there's
something wrong with it, and it will come crashing down, causing you
great liability problems.


Anyhow, being that the tower and guys are part of a system, I'd either
have the loppers take the tree down in stages with sections roped down,
or install temporary guys. Th/e first method is much easier and cheaper.

- 73 d eMike N3LI -

"Michael Coslo" wrote in message
...
Ralph Mowery wrote:

Unless I missed something when I described the tower, what is marginal ?
The first section of tower is set in a yard of cement as described in the
Rohn booklet. Also they only require two sets of guy wires up to 70
feet. I live in the middle of North Carolina so a large build up of ice
or very high winds ( say over 90 mph) would be unusual.


On the "internets", there is always someone for whom your tower setup is
not acceptable. Doesn't matter how well made and installed, there's
something wrong with it, and it will come crashing down, causing you great
liability problems.


Anyhow, being that the tower and guys are part of a system, I'd either
have the loppers take the tree down in stages with sections roped down, or
install temporary guys. Th/e first method is much easier and cheaper.

- 73 d eMike N3LI -

I have noticed that. No mater what you have someone usually chimes in that
it is not the best. I bet I could have said I put one section in 10 yards
of cement and had it guyed with a 2 meter ground plane on it and someone
would do the same. I was waiting on a comeback as to why it needed
improving.

Pix he
http://home.earthlink.net/~ku4pt/ima...%20on%20tower/

I can not put the temporay guy wires on as they would still be where the
tree may fall. There are only 2 trees about a foot or so in diameter and
about 50 to 60 feet tall. Poplar trees without limbs for about the first 30
or so feet.It will only take a short to just cut them. I have seen towers
that don't look near as good stand up long times. I don't think it would be
any problem for the tower to stay up without guys if there was no wind. I
was hoping that someone on here had done something similar over the years
and could say the best way. Drop all wires , or just one side.

Ralph Mowery wrote:


I have noticed that. No mater what you have someone usually chimes in that
it is not the best. I bet I could have said I put one section in 10 yards
of cement and had it guyed with a 2 meter ground plane on it and someone
would do the same. I was waiting on a comeback as to why it needed
improving.

The concrete might not be of good quality - Has a complte workup been
done on the composition? I thought not. Hell, that thing is likely to
fall, and completely obliterate a 10 block area! 8^)



Pix he
http://home.earthlink.net/~ku4pt/ima...%20on%20tower/

I can not put the temporay guy wires on as they would still be where the
tree may fall. There are only 2 trees about a foot or so in diameter and
about 50 to 60 feet tall. Poplar trees without limbs for about the first 30
or so feet.It will only take a short to just cut them. I have seen towers
that don't look near as good stand up long times. I don't think it would be
any problem for the tower to stay up without guys if there was no wind. I
was hoping that someone on here had done something similar over the years
and could say the best way. Drop all wires , or just one side.


That part I couldn't tell ya. Can you guy the trees so to speak? Get a
rope around them somewhere far up and cut to fall in the direction you
want? Pulling on the attached rope via come-along might send them where
you need them to go.

- 73 de Mike N3LI -

I can not put the temporay guy wires on as they would still be where
the tree may fall. There are only 2 trees about a foot or so in
diameter and about 50 to 60 feet tall. Poplar trees without limbs for
about the first 30 or so feet.It will only take a short to just cut
them. I have seen towers that don't look near as good stand up long
times. I don't think it would be any problem for the tower to stay up
without guys if there was no wind. I was hoping that someone on
here had done something similar over the years and could say the best
way. Drop all wires , or just one side.

While I must disagree with my own offering below, I realize your
situation and will offer a suggestion, anyway. I would loosen,
slightly, the remaining two guy wires so as to not have them pulling
tightly on the tower when the third one is removed.

However, I would be concerned with no guy at all in that side of the
tower.... could you remove the guy in question and move it to a
temporary anchor point still on the 180 degree side of the tower where it
might still offer a minimal amount of support?... and could you use a
temporty rope as far to the other side of the 180 degree side in question
and set up a temporary guy there? Without ANY minimal support, should
the tree bump the tower when it is falling, you could have a disaster
without some kind of minimal insurance guys. Heck, even a 20 foot 2 x
4 braced against the opposite side of the tower might be better than
nothing.

Ed K7AAT



..

"Ed" wrote in message
. 192.196...

While I must disagree with my own offering below, I realize your
situation and will offer a suggestion, anyway. I would loosen,
slightly, the remaining two guy wires so as to not have them pulling
tightly on the tower when the third one is removed.

However, I would be concerned with no guy at all in that side of the
tower.... could you remove the guy in question and move it to a
temporary anchor point still on the 180 degree side of the tower where it
might still offer a minimal amount of support?... and could you use a
temporty rope as far to the other side of the 180 degree side in question
and set up a temporary guy there? Without ANY minimal support, should
the tree bump the tower when it is falling, you could have a disaster
without some kind of minimal insurance guys. Heck, even a 20 foot 2 x
4 braced against the opposite side of the tower might be better than
nothing.

Ed K7AAT


Ed the trees I want to remove are not close enough to hit the tower. The
guy wires are almost 50 feet out from the tower and some other trees in
between. My problem is there is a gap between some other trees and it is
almost a funnel effect that will put the tree I want to cut almost on top of
one set of guys. Something like the last 20 or 30 feet of tree could hit
that set of guys.

I don't think I can move the guys that I want to take loose. They might
still be in the line of fire..I will probably wait to cool weather gets
here. Too hot for now when I can be inside playing with the radio.