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[TowerTalk] Tramming help sought

Subject: [TowerTalk] Tramming help sought
From: "Al, N6TA" <>
Date: Sat, 22 Nov 2008 20:54:09 -0800 (PST)
List-post: <">>
I won't bore the readers with the usual retread questions.  Already did the 
reading etc. and lowered the old beam a month ago.  This is one on how to rig 
the haul line to pull up the 110 lb SteppIr yagi.

The tram line is to be rigged about 3 feet above the top on the Rohn 45 tower 
which has a flat top plate.  The boom will be mounted right above the top 
plate.  The tram line is continuous in that it goes thru a pulley and down to a 
'back stay point'.  Trying to allow the tram line some ability to move but 
direct most of the force down the mast to the rotor.

The beam will be hung from a sling that connects a pulley to the tram 
line.  The boom will hang about 18 inches below the tram line.  A tiller/torque 
arm will be attached 'behind' the boom, keeping the boom from rotating in two 
The haul line is half inch polyester double braid and will be tied to the boom 
close to the CG point.  The bracket that holds the tram line above the tower 
top has a place for a pulley to be mounted for the haul line, probably attached 
with a snap link or shackle.  The question I have is how to rig the haul line's 
pulley such that I can  pull straight down and not have interference with the 
tower's top plate.  The bracket for the pulley is about 3 inches out from the 
mast and the tower needs about 9 inches clearance from the mast to go straight 
down without rubbing on the edge of the top plate.  I fear way too much 
friction if I allow this.  I lowered the prior beam this way and used the 
friction to advantage but do not want such issues when pulling up the new beam.
If I rig the haul line pulley ( a CMI 2.375 inch 95% eff. rescue type) such 
that it is hanging out far enough to clear the top plate, I end up pulling 
sideways on the mast.

There must be a standard practice here but I have not yet read any postings 
about this detail.  I usually just 'go for it' and keep the fingers crossed.  I 
have way too many PhDs in the School of Hard Knocks and prefer to not get 

If I can pull the beam up as far as it can get, to the haul line pulley, I plan 
to relax the tram line and let it settle the boom down where it will rest on 
the top plate until I can use other means to raise it the 6 inches to the boom 
to mast plate.
Willing to call to talk about it.

Tnx in advance.

Yeah, I'm missing the CW test due to delay in getting this up.


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