On 8/30/2011 9:14 AM, Jim Lux wrote:
> On 8/30/11 3:51 AM, Tom Kennedy wrote:
>> On any tower of any description a yearly maintenance check is a must, no
>> matter which system is being used. Towers that fail have been left with out
Maybe so and maybe not. Ice storms have take down perfectly good tower
systems. So have high winds that were outside the norm for an area.
> You know.. we see this advice all the time: "It's time for your annual
> spring tower check".. but I wonder.
I see it as a good idea but it gives no guarantee.
And...how does the typical ham check a tower regularly. Remember that
every time you check the torque on bolts it tightens them just a tiny
bit more and if they have never seize on them the listed torque is going
to be way too much.
Guy line tension? that looks/feels about right, or a Loos gauge?
Elevated guy anchors Vs the standard approach?
is the tower still straight?
I typically give it a good once over every couple of years and check the
guy tension by feel. If I find one that is obviously under tensioned or
the guy anchor post shows a definite lean (elevated guy anchors that
weigh 17,000# each) THEN I get out the Loos gauge.
> There's an awful lot of power/telephone poles out there that I doubt get
> checked on an annual basis, and not a whole lot of them fail. Likewise
> light poles, freeway signs. Sure, if one breaks or gets obviously
> damaged, they go out and fix it, but is there some sort of organized "go
> check the poles and signs" activity?
Now days? With money in short supply it took several years (more like
two decades) to get them to clear the right-of-way for the power line
through the woods. It's a mile run across the section to the sub station
and it's woods all the way. In general they do a cursory inspection. IE
if nothing is obviously broken they don't touch it. BTW 5 years after
they cleared the right-of-way it's over grown to the point you can
hardly tell they ever cut it back.
> And on big transmitting towers, I can see regular maintenance being part
> of the plan (you have to paint the darn thing and keep the lights
> working, for instance).
And you can often pop the paint off the rust underneath. Comforting
thought at three or four hundred feet plus. <:-))
Plain steel wire rope guys an inch or more in diameter than ring like a
tuning fork when hit with a wrench. Boy, but those things can sing even
with that brown finish! <:-))
> Likewise, if you have a crankup.. moving mechanical devices need
> periodic checks.
Moving devices need to be moved periodically.
> Maybe it's because hams have a long history of improvisation and
> overloading (if the antenna didn't fall down in last winter's storms, it
> wasn't big enough) or it's from our agrarian heritage (the snow melts,
> time to get the plow out, curry the winter coat out of the draft horse,
> But, for instance, this thing about "checking the ground rod clamp"...
> the whole point of the clamp design is so that it shouldn't loosen with
> thermal cycling (i.e. does the electric company come out and check your
> grounding connection every year? Do you see recommendations that
> homeowners hire a licensed electrician annually?) And of course, one of
> the advantages of exothermic welding over clamps is that there's no
> possibility of it changing. Or is this, again, because hams have used
> all manner of improvised clamping schemes, and "design for immovability"
> wasn't necessarily in the list of requirements.
I think "We may want to move that in a year or so" is the most likely
criteria although those split clamps are about a third the cost of "one
shots" might be the over riding criteria. <:-))
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