John,
Thanks for the valuable info. I also received an off-list reply from David
K1TTT.
The tramline is Rohn 1/4 EHS and is anchored at a large pine tree about 190
feet from the tower base, directly opposite a set of guy wires. Both ends
are terminated with guy grips and thimbles, and a rope with trucker's knot
is used to cinch the ground end to the tree. All guys are HPTG6700I
Phillystran with the top set connected to the flat tower plate, so a back
guy should not be necessary.
David suggested 600 feet of Rhino Rope from WB0W. This should be a good fit
for my application. The tramline is 240 feet. The haul line would be 240 +
150 down the tower + 190 back to the anchor, or 580 feet in total. I think
I may also order a base pulley from WB0W. I have two other steel pulleys,
the kind with swivel hook and little trap door on the side for easy line
removal.
Keith
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of W0UN -- John
Brosnahan
Sent: Monday, June 07, 2004 11:26 AM
To: keith@dutson.net; TowerTalk
Subject: Re: [TowerTalk] Haul Rope
At 10:21 AM 6/7/2004, Keith Dutson wrote:
>What kind of rope should be used to haul antennas up the tower using a
>tramline? For a 150 foot tower how long should it be? Any
>recommendation on a supplier? TIA
>
>Keith WD5DXL
Keith--
I assume that you mean the tram itself rather than the haul (pulling) rope.
I have found that (for me at least) a synthetic rope is NOT the way to go.
Just too much stretch. I have always used a length of 3/16
or 1/4 inch guy strand (1x7 EHS). It has depended on the size
of the antenna and the height of the tower.
It is always nice to get as far away from the tower as possible-- makes the
pulling easier and less chance to interfere with the
guy wires. Since the typical (Rohn recommended) guy anchor
position is 80% of the tower height--I go as a minimum, if possible, out to
the height of the tower--100% of the height or more.
This should keep everything well clear of any interference with the guys on
the way up.
Back guying the tram guy is always recommended unless special techniques are
used--in my case (Rohn 55) I install the top set of guys about 10 ft down
from the top of the tower. This gives me 10 ft of room to install the tram
at the top and allow some room
UNDER the tram for the antenna to hang. And for most antennas
I have found it not to be necessary to back guy the 10 ft of Rohn 55.
Of course others have come up with systems that work for them-- so you will
probably get a number of suggestions from others.
For haul ropes and all tower work in general I use a BRAIDED rope-- so there
is no predominant "lay" of the rope which will cause the rope to unwind when
under load. Mountain climbing ropes are nice and are relatively widely
available at companies like REI. But I have tended to use a rope called
Samson Stable Braid--although the company has changed hands and I am not
sure of the best way to find these ropes today. I prefer Dacron rather than
Nylon.
Dacron has MUCH less stretch and allows better control.
BTW When using EHS for the tram line you will want to use a
steel pulley on the tram. I use a lot of mountain climbing gear--
but most of it is aluminum. The steel guy wire will tear up the aluminum
pulley--making it a threat to synthetic ropes if you ever end up using that
"roughed-up" pulley with another rope.
Hopefully this gives you a few things to think about!
73 es gl John W0UN
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