In a message dated 7/27/03 8:52:35 AM Pacific Daylight Time, DanW8KMX@aol.com
writes:
> I am putting up a HD Rohn BX to 56 ft and a separate Rohn 25 to 60 feet.
> Although Rohn gives some guidelines on the cement base, much is not
crystal
> clear.
> I had decided to overdesign the base and now have holes about 4 ft x 4 ft
> and 6 feet deep. I am now ready to design the rebar system.
>
> I am interested in your opinion about the size of the base and the rebar
> structure.
Rohn discontinued the BX towers serveral years ago so they're not in the
current catalogs. I've heard rumours that they're back in production but any
Rohn product lately has been hard to come by as they're having their problems;
i.e. there is NO new 45G available anywhere in the country.
An older catalog says that for section #8 (the biggest one), they spec a
3 foot deep and 4 foot deep pad. The 3-footer says that it's 6' 6" square with
4.7 cu.yds. of concrete; the 4-footer is 5' 9" square with 4.9 yards. Number
3 rebar (3/8" inch) is used 12 inches on center - all horizontals with the
rebar on the top and the bottom. It's on Dwg. C760099R7 2-19-76.
So that makes your 4x4x6 hole in need of some enlargement to meet the
manufacturer's specs.
Cheers,
Steve K7LXC
|