In a message dated 9/27/02 11:04:11 AM Eastern Daylight Time, firstname.lastname@example.org
> If you're thinking of the TX-455, which is their smallest 55' tower, the
> 2.75 yards of concrete would normally be enough, but only with the standard
> base embedded in a monolithic pour. Drilling for j-bolts or whatever is a
> bit risky, the pour obviously won't be monolithic and you may damage the
> existing structure. I'd probably dig a different hole and start again,
> the U.S. tower base. You can use the existing concrete as a base for a
> barbecue! -WB2WIK/6
If the tower and situation was mine, I would:
Cut the old legs and leave some length sticking out. I could stick expansion
bolts inside the tubing or steel rods with tight fit and weld to beef them up.
I would fabricate steel plate larger than the base of new tower (like
hexagon?). Drill (3) holes to fit over old tower legs, and (3) holes for new
concrete anchor bolts. (End up with six holes evenly spaced.)
Drill holes for new anchors in the base (using plate as a template) and
cement the anchors.
I would weld the new tower base to this plate, place the plate over old leg
stumps, screw the plate to the new anchors, weld the plate to old leg stumps.
This way I would end up with original (hopefully sufficient) concrete base
and structure in it, plus new additional anchors to secure tilting momentum.
The new anchors are usually as good or better than old concacrete (just ask
Jimmy Hoffa :-(