Mike Meehan wrote:
>
> 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
>
> ==================================================================
>
> _/ _/ _/_/_/_/ | Mike Meehan
> _/ _/ _/ _/ | Simulation Optimization Tech.
> _/ _/ _/ _/ | HP EEsof Div., R&D Lab
> _/_/_/_/_/ _/_/_/_/ | 5601 Lindero Canyon Road
> _/ _/ _/ | Westlake Village CA. 91362
> _/ _/ _/ | VOICE: 818.879.6374
> _/ _/ _/ | FAX: 818.879.6394
> _/ _/ _/ _/ _/ | mmeehan@wlv.hp.comI didn't look up your
> answer, but be sure to use 222-F (June 1996) which
supercedes 222-E.
Bill, N3RR
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