I generally put a couple of cement blocks in the bottom of the hole, on their
sides, holes up, the tower legs through the holes in
the blocks and fill with pea stone level with the blocks. The pour concrete on
top of the pea stone. This assures drainage and yet
keeps the tower stable. Never had a problem with drainage or stability.
Dave, W8QW
On Sat 01/30/16 11:45 AM , "Hans Hammarquist via TowerTalk"
towertalk@contesting.com sent:
> Tom,
>
>
> My first question is:" Is there drain holes where the tower legs
> attach to the plate?" If not, drill some, either on the side of the
> legs. You don't what water to accumulate and freeze there.
>
> I can only assume you are going to use guy wires with the tower as I doubt
> a 3' x 3' plate will be big enough to support a self supporting tower.
>
> The size of the foot is all depending on what is underneath. You might have
> a problem with the soil freezing under the concrete plate with unwanted
> results such as a cracked plat, a plate that is lifted in one corner and
> therefore is twisting your tower.
>
> I have seen example there a plate, similar to the one you have, is just
> standing on the ground and stayed that way for a long time with no problem.
> You have to add torque wires to take up the turning force from your antenna
> in such a case.
>
> I sure several towertalk members will add advice.
>
>
> Regards and best 73 de,
>
>
> Hans - N2JFS
>
>
>
> -----Original Message-----
> From: Tom Hellem <tom.hell
> em@gmail.com>To: TowerTalk <Towe
> rTalk@contesting.com>Sent: Fri, Jan 29, 2016 12:38 pm
> Subject: [TowerTalk] Rohn 45 Base Section
>
> I acquired several sections of Rohn 45 lately and the one
> that was used as a base section looks like a regular straight
> section with a heavy galvanized plate welded to the bottom
> of it. The plate steel is easily 1" thick, and the entire assembly
> must have been sent to the galvanizer as all the welds are galvanized
> as well as the plate. The edges of the plate project beyond the faces of
> thetower about 7" on all 3 sides.
>
> My question is, if I pour a concrete pad say 3' x 3' x 16" deep and
> embed 31" anchor bolts in it for bolting the base down to it, will it be
> equalor close to equal in strength as a tower section embedded in the same
> concrete?
>
> My plan is to erect 40 feet and place a Force 12 C-3 atop it ( I think
> 7SQ Ft or so)
> and attach it to the gable end of my roof with a house bracket at the
> 16'level.
> The roof structure will be beefed up substantially to accommodate the
> bracket.
>
> I know the Rohn book probably won't allow it, but what does the
> collectivewisdom
> say about my chances of it staying in the air? I live in Missoula, MT.
>
> 73
>
> Tom
> K0SN
> _______________________________________________
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