DIYbanter - View Single Post - Is my swing set gonna be safe, now I'm doubting myself?

wrote:
So my question is, will the
6"x6"x12' that I will use instead of the traditional A-frame be strong
enough at the base to support the swinging? If not I guess I could add
some 4x4 supports, but that brings up the next question of how high and
what angle would I need to put them?

Sounds like a very solid design - I've seen (and played on, a while
ago) many that are far less sturdy than that, some that have/had been
up for many years. For example, the "play structure" that my father
built many years ago was a 6-7 foot high platform on 4x4 legs with a
2x4 frame for the plywood platform. It survived many years of abuse
from many neighborhood kids, and was only removed when we outgrew it.
I agree that the swinging motion on the single upright post might be
the weakest part, but in my non-expert opinion, a 6x6 sunk deep in the
ground with a bunch of cement should be fine, unless you regularly have
multiple large adults swinging "in phase" with each other. Smaller
kids, who will probably be swinging out of phase some of the time,
shouldn't be enough to stress a 6x6 too much. If it were me, I'd leave
it as is, keep an eye on it, and if it starts to show signs of wiggling
in the ground or cracking, then brace it up with 4x4's.
(Take this with a few grains of salt, of course...)
Good luck,
Andy