This is dependent on the part of the USA you live in. Those of us
that have live in the Dakotas and northern regions of the US and have
done Commercial tower install's know this can be very dangerous. Water
pipes can freeze solid buried 6 feet in the ground, usually in January or
February. The danger is during spring thaw, the ground becomes very
soft and unstable the full depth of the thaw, and can cause very strong
lateral stress on the tower. Shallow or surface cement bases have been
know to collapse a tower because the base sank much more on one side
than the other, (one side thawed faster because it had more sunlight, a
large rock was under one side, or ??) enough to buckle the tower right
above ground, and bring it down. Rohn specs are designed for the worst
case, to protect themselves from premature failure.
73's de Stephen, K0SD in NC
******************************
> And what do you see as the problem?
>
>
<clip>
> W1EVT has 19 R25 Towers 140 ft tall sitting on base plates
> supported by cinderblocks to place each base at the same elevation.
> There is NO lateral support at the base other than friction on
> the cinderblocks. These towers have been up for around 40 years
> that I know of. It is NOT necessary for a GUYED Tower to have
> a base rigidly attached to a large mass of concrete. It only
> needs a base that can support the Vertical Forces from the tower.
<clip>
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