I had the opportunity to put my new WB0W gin pole to use
this past weekend with a pair of antenna projects, so can
offer the following observations.. bear in mind that my
last view of a gin pole was as part of a ground crew 25
years ago, and I don't even recall if that was a Rohn or
homebrew. Nevertheless.. Saturday's project was to place
a new 2 element quad on top of WQ9E's 60 foot Rohn 55. The
rotor and mast were already in place, it was only necessary
to haul the quad up, manuver around a single set of guys
with a tag line and slip the boom to mast plate with
U-bolts over the mast topside.
Starting as a two-man operation, with me on the tractor and
the rope going through a base pully up to the gin pole, and
Roger on topside manuvering the quad, the 2 el tribander
was manuvered around the guys and up to the top quite
easily. Unfortunately, perhaps to slight winds, the
balance point of the quad assembly shifted somewhat between
the bottom and top of the tower. Considerable effort and
very slow forward and back motions on the haul rope would
get the bottom U-bolt within a quarter inch of the proper
position to slip over the mast, but it wouldn't quite go.
After 15 minutes of near-miss efforts, another local ham
was summoned to assist topside. The extra pair of hands
upstairs allowed the installation to complete within a
minute or two.
Afterthought.. if you are using a plate/U-bolt type of boom
to mast attachment, and the assembly needs to slip over the
top of a mast, install an extra pair of oversize U-bolts
outside of the mast-sized bolts. The oversized U-bolts
would allow the boom to mast plate to slip over the mast
quickly, after which the standard bolts could be installed
without much effort. More complex boom to mast assemblies
might also apply, saddle mounts, U-channel, etc.. but if
all you have to work with is a square or rectangle of
quarter inch steel, this might make installation easier.
Or, use separate plates, one fastening to the mast with a
stub bolt sticking out to 'hang' the plate attached to the
boom on, as with the Force 12 antennas (just received my
catalog today, neat idea!). Once the appropriate hole in
the boom plate is slipped over the stud bolt, manuvering to
place the remainder of the bolts holding the two plates
together should be easy.
Both of the climbers were experienced in tower work, and
both had excellent comments about the WB0W pole. Easy to
attach/detach clamp, and very smooth sliding of the pole
portion through the mast. The 2 inch 6061 quarter inch
wall mast (12 ft) may also be stronger than the Rohn pole.
It is rated to handle up to #55 sections by WB0W. The
optional positioning holes in the clamp assembly lead me to
believe it would be useful for anything from BX to any
round-element tower from an inch to two inch diameter
vertical sections to clamp on. No visible flexing of the
pole at all as the 50 lb quad was lifted and manuvered
around the guys. Not bad for half the price of a new Rohn
pole.
The clamp and rooster head, as shipped, seem to be painted
with a fairly soft powder-coat type of primer. I repainted
before use, and plan to do so between uses.
Regarding which direction to point the rooster head.. after
the next day's project, that being disassembly of a newly
purchased 68 ft Rohn 25 foldover for eventual reassembly at
my QTH, it occured to me that it should be fairly easy to
fabricate some sort of quick clamp with a short handle that
could be attached to the gin pole mast right above the
clamp. Assuming it was hefty enough to prevent the gin
pole from slipping back down through the clamp when the
T-bolts were loosened slightly, it should be possible to
swing the head around to assist with positioning as new
tower sections are placed. With #25, it probably won't be
an issue, but this approach might come in handy when
lifting #45 or 55 sections.
Safety note.. dropped tools can present a large danger area
around the base. A socket wrench was dropped, rebounded
off of one of the quarter inch EHS guys and landed 30 feet
from the base. Keep the ground crew well back. This led
to my Saturday night attachment of 2 foot ropes and clip-on
clamps to all the tools I figured I would need for my #25
take down project, so they could be clipped to the tower at
the appropriate work level. That worked well, but I didn't
take the process far enough. I'll cover the tower takedown
and the use of the WB0W hydraulic tower jack in a separate
post.
73! - Mark
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Mark Shaum K9TR
mashaum@fcg.net
Central Illinois Grid EN50
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