In a couple weeks, I'll be taking down a 58' Rohn 25 foldover for a 3 mile
move to this QTH. Since I've never been involved with the disassembly of a
tower, I'd like to make a couple inquiries:
I'm assuming that I will run into some sections that won't come apart
easily on this 15 year old tower. I plan to spray all bolts/joints with
penetrating oil about 3 days before disassembly time and again a day
before. I would like some comments on the use of a propane torch to heat
the 'stuck' joints. With most metal components, I've found that a
combination of heat and lubricants will generally do the trick. Outside of
damaging any paint, will a propane torch do any damage to the galvanized
coating and/or general strength of the steel at the coupling point? I can
also take up a small scissors jack, but the crossmembers on #25 are so
thin, I'm concerned about warping or breaking the welds if a jack is used.
Assuming I can get things off down to the hinge section, is it feasable to
bolt the hinge together (Rohn literature refers to a 'shipping tab' of some
sort used for this purpose), and then lower the entire boom assembly with
the gin pole?
I don't think I'll have any assistants climbing up with me. Hopefully the
40lb 25G sections will be manageable, but I'm not sure about that boom
(100-150lbs?).
If I survive the takedown, I plan on general cleaning, wire brushing if
required, painting or galvanizing spray, new hardware, new guys/turnbuckles
and anchors. Am I missing anything?
About the guying.. Rohn seems less than their usual conservative opinions
when it comes to guy specifications. 4ft by 6in screw anchors? (Although
I am told by a local installer that with our soil, these things will hold
well beyond their 2500 lb ratings). And even for a heavier/taller #45
foldover, the guy placement recommended is only 30 ft from the tower base?
Granted, this is a four guy arrangement rather than the usual 3, but
still.. I'm tending towards a traditional anchor/equalizer plate using a
3x3x1' concrete block. Or do the screw-in anchors work? I'd also prefer
to get the anchors out at least 40' from the tower base, unless the 4 vs 3
guys at hinge and apex really gives enough advantage to get by with the
smaller footprint.
Final question.. can somebody forward an address or telephone number for
WB0W (the gin pole man). $495 for the Rohn EF2545 gave me a bit of sticker
shock. And as an FYI, Rohn no longer supplies adapters for #55 (I plan a
55 installation next spring), and may cease production on the EF2545 soon.
Apparently there is a liability factor that is scaring off most of the
ginpole manufacturers.
----------------------------------------
Mark Shaum K9TR
mashaum@fcg.net
Central Illinois Grid EN50
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