On Tue, Mar 8, 2011 at 8:57 AM, Jim Brown <jim@audiosystemsgroup.com> wrote:
> 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.
Thanks Jim and JP. That's very useful information.
I don't have massive redwood trees. All of the trees on my property are live
oaks and the largest is probably only 25' tall and not very massive, so I
won't be able to use them for guy anchor points. I'll need either concrete
anchors something that expands or screws in to the soil (adobe clay).
Jim - how far is your tower from your shack and what type/length of feed
lines did you use?
- 73, Jerry
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