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April 14th 05, 04:04 AM

K7MEM wrote:
wrote:

I just purchased a tilt-over mast that I'd like to erect:

The base section begins with a 16"-square piece of 1/2" steel with four
holes on 12" centers and is welded (with four pieces of steel, sorta
like rocket fins) to a pipe which rises 17.5' to the pivot point.
The tilting part extends 16' further. All of the above pipe is 2 3/8"
in diameter, but a smaller-diameter pipe (for mounting a rotor?) sticks
out the top end of the tilting section another foot or two.

Can someone suggest how big a blob of concrete and how much rebar I'll
need at the bottom to erect this mast to be freestanding?

I have a Triex W-51 Crankup in my yard. Collapsed it is about 22 feet high
and extended it is 51 feet. The manufacturers recommendation for the "blob"
of concrete is 3 feet by 3 feet by 5 feet deep, roughly. This is about
1.5 Cubic Yards of concrete. I don't have the specs handy, but I believe
the rebar mount extended about 3 feet down and was centered so that it
is at least 6 inches from any side. To make sure that everything sits
where it is suppose to, and will be plumb when erected, the rebar mount
was bolted to a 2" x 6" wooden form, leveled properly, and then the
concrete was poured around it.

There is a reflector around called something like "Tower Talk" that would
be able to give you more details and advice. However, I don't remember the
link. Maybe someone else can supply it.

It's a fairly big job and takes a bit of planning.

Keep in mind that some cities engineering departments are ultra
conservative and will double or triple(!) their requirements over
what the tower maker recommends. This happend to a friend of mine
who ended up with about 3-4 cubic yards being poured for a 20' crank up