crank-up's and dead load spec...

[Mike Meehan]

Hi All,

OK, I've got my permits in hand for 2 crank-up's on my
one acre city lot. I've been looking at the super heavy
duty US tower 689 and 5106. The engineering calcs for
the 689 indicate 30 ft^2 windload in 70mph exp2, and
200# deadload according to EIA 222E.

Can someone explain what assumptions are in 222E
regarding the dead load spec?

It seems kinda puny to me, when you add up a
HD mast and rotor there's hardly any margin left
for 30 ft^2 of antenna...

The only thing I can rationalize is that the compromise
between the mass required to accommodate the high windload and
the hoist system is tilted in favor of windload for US towers'
designs.

My hope is that the conformance to 222E includes a huge safety
factor or some other implication regarding dead load.

Any practical experience (including horror stories about
crank-ups (I'd like to share them with the city engineer)
would be appreciated, and in particular about practical 
loading of these specific towers.

I've scoured the web for info on this subject but came up
empty (except for the towertalk list address)---If you know 
of a source, please let me know. Also (as usual) if there 
is enough interest, I'll summarize results...

(I know about the engineering superiority of stacked
sectional towers so there's no need to school me there :)
Its just that my city ordinance doesn't allow them.)


Kindest Regards,
-Mike AK6N

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