Hello-
Just thought I would throw these tidbits of info into the " watch out for's
" regarding the tubular leg tower 25-G, 45-G :
#1. I take down older towers at times and clean up the sections, etc.
One thing I learned to do was to run a large rod or small tubing through each
leg on the straight sections. On some of the older sections the bolt retainer {
remember how they shipped the bolts in the legs} that was furthest up in the
leg would nearly always remain there, unless someone deliberately sought to
remove it. It would be about 6 to 8 inches or so up into one of the legs from
the bottom. This retainer was made of metal. I have drove out many of them that
had been in a tower leg possibly 30 years or more. All of them were rusted to
some degree, some were rusted up badly. Quite a few of them had been holding up
a certain amount of water it appeared. On one 25-G section I rejected using it
because it appeared badly rusted internally at the place where the metal bolt
retainer had been. On this particular one I had some problems driving out the
remnants of the retainer and it was badly deterior
ated. I went ahead and sawed the leg at the location of this damage { to
further insure that this section would be never used again} and after I forced
the leg apart a little at the cut I could definately see damage to the wall
thickness { from the inside}. On the top sections the retainers must be
"fished" out of the legs by catching them with a strong piece of hooked wire,
etc. These metal bolt retainers are something to think about on the older
towers as most were left in and with the odds of 1-in-3 of getting one in each
tower leg as you stack I would guess that in an erected tower of much height
you would have one or two at various levels to rust, collect debris and water,
corrode, etc. the internal wall.
2. Recently I took down a 25-G that was 60 feet tall, house bracketed at 22
feet, and not guyed above the bracket. A 3 foot concrete base section was used
with about 2-1/2 feet of it contained in a concrete base about 18" square.The
tower had supported a TH-5 for about 32 years. I inspected the tower starting
at the base and noticed nothing that concerned me, there was a ground wire
attached to one leg right above the concrete. The wire was aluminum going to an
old ground rod I could not tell what type. I went up the tower and guyed it
temporarily with 3 strong ropes at the top section and removed the TH-5. Then,
I started moving my guys down one section at a time and removing the sections
until I got to the house bracket.When I disconnected the tower from the house
bracket it developed a lot more sway than I would have expected, so I climbed
down and found that the leg where the ground rod was attached was completely in
two - it appeared almost as if someone had cut it wit
h a pipe cutter.The wall thickness was paper thin right at that spot, it
appeared to be progressing from the INSIDE as the external surface of tower
showed no sign of anything going on. I never understood on this one if the
ground connection played a role, but we did not see any water trapped in the
legs of base however.
Just some info, thanks, WA5THJ.
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