On Mon, 5 Aug 1996 14:36:36 -0700 (PDT),
w7ni@teleport.com wrote...
>Steve: a number of times I've seen references ON A COUNTY basis to
>>>wind force design criteria. do you know where I can obtain this info,
>>>hopefully on line? my old, old, old Rohn book only has a map of the
>>>US. I'm curious as to the design criteria for Cheshire country in the
>>>stick of NH.
>>>
>>Hi, Charlie --
>>
>> It's listed in the EIA/TIA-222-E and F, the newest revision
>effective
>>June 1, 1996. I have copies and am happy to look them up for interested
>>folks. My plan is to get my Tower Tech web page up and running and
>>eventually have the info on-line as I don't think it exists anywhere
else.
>> The pubs run $80.00 each so not everyone is inclined to have them in
>their
>>library.
>>
>> Cheshire County is a 75 MPH zone but is within 100 miles of
>hurricane
>>coastline and the values have been adjusted in accordance with ASCE 7-88
>to
>>obtain 50-year recurrence intervals. In other words, check with you
local
>>building department to see if you are subject to higher winds at your
>site.
>> BTW, 70 is the lowest value that the charts contain so your zone isn't
>too
>>bad except for the proximity to hurricane coastline.
>>
>>73 and good luck, Steve K7LXC
>>
>> TOWER TECH -- professional tower supplies and services for amateurs
>>
>
>Since 70 mph is the minimum listed wind velocity for ANYWHERE in the US,
>how
>come crankup towers are always rated for 50 mph? I think I know why. You
>can't put any load on them at 70 mph, at least with any kind of safety
>factor. I think we, as a group, should demand 70 mph ratings from crankup
>manufacturers. I know this will negatively impact their business . . . as
>it should!!
>
>Stan w7ni@teleport.com
>
>
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