[TowerTalk] Help Needed Replacing Crank-Up Cable on US Tower

[Julio Peralta]

I've had to do 3 re-cabling jobs. One a 72' UST where one of the cables
was so bad it broke. One a 89' UST where the cables had more than
surface rust and had more than the 6 strands broken rule of thumb. One a
105' Triex that belonged to a cell phone company that was worse than the
89 footer and was just before breaking. 

It's not easy but if you take your time you can work your way through
it. I will mention that not all the cables can be pulled through by
attaching them to the just removed cable due to the fact that the Nico
press (sp?) clamps won't pass through the sheaves so they must be
removed. The other thing I've learned is that the tension on the pull
down cable must be set with some weight on the top section of the tower.

Steve would you agree with this?

Julio, W4HY

-----Original Message-----
From: towertalk-bounces at contesting.com
[mailto:towertalk-bounces at contesting.com] On Behalf Of K7LXC at aol.com
Sent: Tuesday, June 06, 2006 9:17 AM
To: towertalk at contesting.com; DrD at 2020.com
Subject: Re: [TowerTalk] Help Needed Replacing Crank-Up Cable on US
Tower


 
In a message dated 6/5/2006 9:02:43 A.M. Pacific Daylight Time,  
towertalk-request at contesting.com writes:

>  I just purchased and have brought home US Tower, model  HDX-572MDPL, 
> 72'
Heavy
Duty tower from the estate of a SK.    

>  It has a motor drive whose design includes a postive  pulldown 
> feature.

>  The tower contains 4 sections, was  installed in 1999 and has had 
> little
use.

>  Where I need help:

>  US Tower recommends replacing the cable every 2-3 years,  which may 
> be an
overkill but is definitely erring on the side of  safety.  Since my
tower is 7 years old I'd like to start out with  fresh cabling. 
 
    The UST recommendation is known as a "weasel  clause"; that is, if 
something happens to your tower and you hadn't changed  the cables, they
can weasel 
out of any liability. Tower manufacturers are  insurance-driven
enterprises so 
it's no surprise they are reluctant to  provide any helpful information.

 
    The other gotcha is that there isn't anyone  around who can do the
cable 
change anyway. I spent a couple of days at the  factory to learn how to
do it 
and what I found out is that it's an involved  and semi-complicated
endeavor. 
It's not something I would try myself. 
 
    I'll bet you a nickel that you don't have to do  anything other than
lube 
the cables and you'll be good to go. The actual  circumstances that
would 
require cable replacement are: 1) Excessive broken  strands. Industry
standards 
allow you to have six broken strands before  replacement is necessary.
2) 
Excessive rust - not surface rust but real  cancerous into the strands
rust. 3) 
Damaged cable. This would be kinks or flat  spots in the cable. I doubt
that your 
cables meet any of the above criteria.  

OTOH you should lubricate the cables annually at  a minimum. Champion
Radio 
Products sells PreLube 6 which is recommended by the  wire rope
manufacturers. 
 
    You should exercise the tower a couple of times a  month by running
it up 
and down. You should also park it at different heights  rather than just
at 
the limit switches all the time. The cables can take a  permanent set by

sitting on the pulleys at the same spot for years.  By doing these 3
things, you 
will prolong the service life of your  cables.
 
    BTW I have never personally seen a ham tower that  the cables were
so bad 
that they had to be replaced. Some were pretty grungy  but didn't meet
the 
aforementioned criteria. 
 
    Lube it and enjoy it and don't worry about  replacing the cables.
 
Cheers,
Steve    K7LXC
TOWER TECH -
Professional tower services for hams
Cell: 206-890-4188



 
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