I thought the reflector might like a report on the
raising of my X9 on May 15, 1999.
The 100' crane arrived at about 7:30 AM. I was
surprised at the small size of it. It is capable of
hoisting several thousand pounds, but the operator
left off most of the counterbalance weight. My
driveway is very glad of that. The boom is trans-
ported folded in half. The first thing that the operator
had to do was fold out the boom to it's full length.
This required a sledge hammer to set the pins, but the
boom was now about 50' long. The boom telescopes
into the second section and allows the crane to extend
to about 100' I didn't notice the number of telescoping
sections.
The one thing I did notice was the boom was higher than
me -- not something that I am used to on the tower!
While the driver and crane owner were setting up the crane,
I climbed the tower and removed most of the TH-7 hardware.
By the time the crane was ready I had removed everything but
the boom to mast. I put two large nylon straps over element-to-
mast clamps and had the operator put a little tension on the
straps. This crane and operator were able to modulate the
movement in tiny increments. I removed the TH-7's boom to mast
clamp and the antenna swung away. Unfortunately, I forgot to remove
the boom-side piece and the bolts that can fall. The mast clamp
fell to the ground, but no one was near it, and it missed the house.
Don't make that mistake with yours! I was lucky.
The operator was able to pick up the TH-7 and deposit over the
house and onto the driveway with the aid of a tag line that I had
attached and the help of KQ2M. His help was invaluable. The
operators of the crane are used to installing signs, not tribanders
and needed help to watch the elements so that they were not bent.
KQ2M's eagle eye prevented any damage.
While the ground crew was dropping the TH-7, I was attaching the
X9's boom-to-mast clamp. This is a "shelf-like" clamp that
I thought was going to make things easy. Because of poor planning
on my part, it did not. The idea is that you mount the "shelf" on the
mast, then let the antenna down on it. You then mount a molded piece
of aluminum on top of the boom to hold it in place.
The removal of the TH-7 went smoothly, partly
because I had previously removed the two center elements. There
was a wide space for the crane's boom to fit in. The X9 was fully
assembled and had much less space between the elements. This
caused a problem with installing the X9 on the boom "shelf". Twice
I mis-estimated the proper angle for the shelf to receive the boom.
So twice I had to loosen & move the shelf to hold the boom properly.
The last time I had to move it, was because one of the elements was
being touched by the crane's boom and put the X9's boom out of
alignment. If you have to install an X9 with a crane or with a gin pole,
I would recommend leaving the clamp loose, until you can properly
judge the attachment azimuth.
After a while fighting with the boom-to-mast clamp, I was able to
get it secured. That's when the second problem occurred One
of the two tag lines the ground crew had used to maneuver the X9
around while it was being raised, snagged on the reflector's hard-
ware. Believe it or not, the crane operator put on a harness and
his boss hoisted him 75' into the air and he cleared the snag. Try
that with a gin pole!
All-in-all the operator took about 2 1/2 hours to accomplish. Certainly
a lot faster than disassembling the TH-7, dropping it, then assembling
the X9 on the tower. You'll notice that I did not say how much the crane
cost. The owner of the sign company is a friend and he refused to charge
me. All I had to do was pay the operator. Is that a friend or what?
I hope you found this description interesting.
Tom Wagner N1MM
By the way, the X9 works great -- I'm working Asians all over the place,
getting most on the first call. It is a beast, 28' long and 36' wide, but
it
seems to work!
----- Original Message -----
From: Tom Wagner <tomwagner@mindspring.com>
To: <towertalk@contesting.com>
Sent: Sunday, April 11, 1999 6:32 PM
Subject: [TowerTalk] How do you remove guys to walk a beam up Rohn 25?
>
>I just bought a Cushcraft X9, and have been thinking about
>how to raise it. Tramming is out, I just don't have enough room.
>I had resigned myself to building it on the tower -- a prospect
>that took another X9 owner 6 hours. Ugh! The X9 has a
>28' boom, 9 elements and the longest element is 36'
>
>I was browsing KC1XX's web site and found an idea that
>intrigues me. He raised W4AN's new 40m beam by walking
>it up the tower and detaching/reattaching guys as he went.
>
>Has anyone done this? Here is how I would envision it:
>Element tips pointing up, walk the beam
>(with gin pole assistance of course) to
>the first guy level. Attach a temporary guy wire just below the
>boom and tighten a come-along until the first torque bracket bolt
>comes out easily. Move the antenna past the first guy level, and
>reattach the old guy. Remove the temporary guy and move to
>the second guy level. Repeat the procedure at each guy level.
>
>Questions:
>
>1. Is an ordinary come-along safe for this purpose? If it gives way,
>the tower will be subject to unbalanced forces and could collapse.
>Should the guys be loosened at each level, before using this
>approach? Would two temporary guys be better than one?
>
>2. My tower is 75' of Rohn 25 guyed at 3 levels with 1/4" EHS,
>somewhat over-guyed, but well within spec for downward stress.
>
>3. Does this seem safer than spending 6 hours on the tower?
>It sure is less work.
>
>Has anyone used this approach. I'd like to do this safely, but
>without 6 back-breaking hours at the top of the tower. Even
>if it took longer than 6 hours to do it right, it would be better
>than building it at the top. It would also be better, in that
>I could test it at the first guy level for proper operation and
>correct problems much more easily than using the other
>approach.
>
>Please post replies to the reflector.
>
>Tom Wagner, N1MM
>
>
>--
>FAQ on WWW: http://www.contesting.com/towertalkfaq.html
>Submissions: towertalk@contesting.com
>Administrative requests: towertalk-REQUEST@contesting.com
>Problems: owner-towertalk@contesting.com
>Search: http://www.contesting.com/km9p/search.htm
>
--
FAQ on WWW: http://www.contesting.com/towertalkfaq.html
Submissions: towertalk@contesting.com
Administrative requests: towertalk-REQUEST@contesting.com
Problems: owner-towertalk@contesting.com
Search: http://www.contesting.com/km9p/search.htm
|