Steve I wonder how close to a salt water environment you are. Here in the
Tampa Florida area I've seen several very rusted cables (including guy
wires). Many years ago I had a 72' UST fall due to a rusted cable that was
about 5 years old. That tower was installed about 30 miles inland from the
Gulf of Mexico. The reason I didn't notice the cable was in such bad shape
is that only the two upper cables were badly rusted and only on the side of
the tower that faced the Gulf which was the opposite side of where I stood
when I operated the switch to lower/raise the tower.
I also have worked on a UST on the East coast that fell for the same reason.
Julio, W4HY
-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
K7LXC@aol.com
Sent: Friday, June 14, 2013 4:08 PM
To: towertalk@contesting.com; fred.hurd@cox.net
Subject: Re: [TowerTalk] When To Replace Tower Cable???
> This seems to be a constant question for those of us who have
> crank-up
towers. How can you tell when it is time to replace the cable? Some say
that it's too late when rust appears as the cables weaken from the inside
out.
Is that true? Others say if you lubricate the cable twice a year it will
last forever? Is that true? Does anyone know the truth?
You bet. There is an excellent chapter in UP THE TOWER on crank-ups and
their related topics.
There are 3 conditions that determine whether the cables need
replacing. 1) Excessive broken strands. Out of a 7x19 typical wire rope,
you can have up to 6 broken strands and 3 in the same bundle and still be
within spec. 2) Damage where the cable has been flattened or kinked. 3)
Excessive rust. Not everyday simple surface rust but the real cancerous
kind.
My experience has been that I've only seen one crank-up with cables
that genuinely needed replacing so if you are a crank-up owner, chances
that you have to replace the cables are slim to none.
I've seen really mature crank-ups (20-25 years+) where the cables were
just fine and didn't meet any of the aforementioned replacement criteria.
Replacing cables that don't need it (besides being time-consuming) is
analogous to folks who buy chromoly masts when they don't need them. Both
are basically a waste of money.
Cheers,
Steve K7LXC
TOWER TECH
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