[TowerTalk] US Tower damaged by lightning - now cable lubing

[K7LXC at aol.com]

In a message dated 5/2/2010 9:59:22 P.M. Pacific Daylight Time,  
towertalk-request at contesting.com writes:

>  If the cables don't need replacing at the rate "the  field" is replacing 
them, then why do we get any cable breaks?
Are  there other issues?


    See the email I just posted about  cables breaking.

>  Most hams don't do much maintanence, from  the cables on used towers 
I've 
bought. So it's hard to understand an  anecdotal story of "most cables 
that are replaced don't need to be".
 
    Well, as a UST factory authorized installer and  installer of a dozen 
or more crank-ups, I also do PM to them so I've seen lots  of older crank-ups 
and that's been my experience. Amateur use is very  occasional as compared 
to commercial service and isn't subjected to hard daily  use.

>  Worse is the problem with lack of bearing maintainence.  I've seen 
severely worn bronze bearings.
And corrosion/wear on the  aluminum pulley wheels, sometimes leading to 
very hard to turn.


This is true for older crank-ups but for years  they've used pressed-in 
sealed bearings which are much better. It's almost  impossible to see the 
pulleys move in most UST's, hence the move to a higher  reliability pulley. 

>  If replacing cables at X interval isn't fixing the  problem, what will?
I think any used tower needs it cables replaced and  pulleys rehabbed.
 
    Maybe. 

>  I've gotten a tower  where the cables were replaced with apparently EHS 
cable: very hard to  cut, had to use angle grinder. Owner apparently 
thought stronger was  better, but it was stiffer and probably worse over 
the narrow diameter  pulleys.
 
    I don't know what it was but it wasn't EHS. EHS  is very difficult to 
bend and wouldn't work in any other application except  for straight pull guy 
wires. 

>  I'm guessing, on the west  coast, that 10 years might be the right 
period 
for cable/pulley  teardown.
20 years seems too long. Maybe 5 is too short. Any time it  changes 
owners seems right too.


Time has nothing to do with it - it's cable  condition. I recently posted 
the 3 reasons why you'd want to replace the  cables. They are damage, bad 
rust and excessive broken strands. None of the  crank-ups I've seen or worked 
on met those criteria so they didn't need  replacing. 

>  Where do the cables break? I've seen a photo of a break  near the 
compression sleeve, and I've read some inspections that detail  the area 
within 1 ft. of a compression sleeve as warranting extra  inspection 
because of possible increased stress/damage to the wires during  the 
compression sleeve install.



         It's more due to  external forces. See my related post.
 
Cheers,
Steve    K7LXC
TOWER TECH