[TowerTalk] Tramming

[Keith Dutson]

Yes, it would be nice to use Phillystran or other Kevlar products.  But
there are two real big negatives that will keep most from doing it:

1. Expense - 1/4 EHS equivalent is 6700, $1.29 per foot, plus $12 each for
big grips (cannot use clamps);

2. Danger - Kevlar can be cut with a knife, or an unlucky encounter with an
old pulley rim.

My 500 foot roll of 1/4 EHS came delivered in a steel banded coil of about
2.5 feet diameter.  I can roll it back to a 3 foot coil without a lot of
trouble and use tape or twine to hold together.  Seems a small task compared
to the cost/risk of Kevlar.

Keith NM5G

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of Tower (K8RI)
Sent: Tuesday, August 17, 2004 3:32 PM
To: Jim Idelson; TowerTalk Post
Subject: Re: [TowerTalk] Tramming

My preference would be one of the Kevlar based cables which is what I use
for guy lines.

Although much easier to handle and store, lighter weight, and though they
are much easier to damage then EHS.  That means the tram needs to have good,
smooth pulleys, and no sharp edges.  The ends also need to be sealed from
moisture.  Due to their light weight and strength they have very little
catenary.  This really shows when you run a tram up one carrying a heavy
weight as there will be a pronounced dip at the tram the size of which
depends on the weight and cable tension.

Even taking all that into consideration, I still prefer the Kevlar cables.


Roger Halstead (K8RI, EN73 & ARRL Life Member) N833R, World's Oldest
Debonair (S# CD-2) www.rogerhalstead.com

> Thanks for all the responses. Looks like EHS is the way to go. I like 
> the idea of using Big Grips on the ends so that the terminations are 
> adjustable and so the pulley can travel right up to the mast. The only 
> thing I don't like about this solution is the difficulty in storage. 
> I'd prefer a more flexible material that can be rolled more easily 
> into a smaller roll.
>
> 73,
>
> Jim Idelson K1IR
> email    k1ir at designet.com
> web    http://www.designet.com/k1ir
>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers", 
> "Wireless Weather Stations", and lot's more.  Call Toll Free, 
> 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
>
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> 


_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any
questions and ask for Sherman, W2FLA.

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