On 3/7/2011 3:05 PM, J.P. wrote:
> Having done this myself, the answer is sure you can put up a guyed tower on a
> slope. What's important to maintain are the angles of the guys to the tower
> and the tension on them. If you maintain the same angles relative to the
> tower, some will be shorter (uphill) and some will be longer (downhill) but
> other than that there's not any magic besides basic geometry.
Good advice. I did exactly that with my tower, where the terrain slopes
both a little and a lot, depending on directlon. I'm in a rather dense
redwood forest. The guys going in one direction hit the ground 20 ft
above the tower base, and in another direction, 15 ft below the tower
base, but I held the specified angles. It took me a year to find a spot
where I could turn a beam with a 22 ft turning radius. I've got the
specified 4 ft deep x 30 inches x 30 inches of concrete under it. It's
too far from the road for a truck, so we mixed and poured on site, using
a small mixer owned by some friends. Carried gravel and bags of cement
about 350 ft in a wheelbarrow, ran a long hose and AC power down from
the house. Took us about five hours. That's the only concrete I poured
-- all the guys go to big lag screws a few feet above the base of very
tall and massive redwoods (avg height 150 ft, 5 ft diameter). Each guy
wire goes to a different tree. Guys are at four levels, so that's 12
wires, 12 trees. (If you've got one redwood, you've got a lot of
redwoods around it, because redwood trees have LOTS of children).
Obviously, this won't work for everyone. :) The tower is 120 ft of Rohn
25.
Another VERY important consideration in irregular terrain is the
stability of the soil -- that is, if it's on a slope, will two tons of
concrete that you put in a hole stay there, or might it slide downhill?
I'm about to install a second, shorter tower, about 40 ft, to hold
monobanders for 10M and 15M. One spot I was considering is on a fairly
steep slope that didn't look sufficiently stable, so I'm going to use a
different one.
73, Jim K9YC
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