[TowerTalk] Rohn HDBR48 and International Building Code

[Alan Beagley]

Perhaps "calcs" are more comprehensive, but the AN Wireless Web site has 
a table of permitted loads/areas for *their* towers all the way up to 
120mph.

Alan AB2OS


On 03/17/04 08:41 pm Alan C. Zack put fingers to keyboard and launched 
the following message into cyberspace:

> I'm sure someone will have a more accurate or more technical answer to
> your question.  I'd just like to pass on my personal experiences
> similar to yours.
> When I moved to this QTH I thought it would be a relative easy matter
> to put up a U.S. Towers MA-40 tubular tower.  I got the base
> foundation drawing from the U.S. Towers (UST) web site.  I took it to
> my bldg dept and the inspector said the drawing was fine, all I needed
> was a Nevada PE wet stamp placed on the drawing.  But as I got up from
> his desk to leave, he mentioned, by the way, we also need 90 MPH wind
> calcs.  Those few words have turned into a nightmare.  Seems the
> industry standard is 50 and 70 MPH wind calcs under the code UBC-97
> that most tower companies use.  UST told me they were unable to
> provide me with 90 MPH wind calcs and I should check back with my bldg
> dept as 50 and 70 MPH were standards.  I called my bldg dept and they
> informed me 70 MPH was the standard under code UBC-97 but most cities
> have now gone to 90 MPH wind calcs under code IBC-2000.  So I am now
> stuck trying to get 90 MPH wind calcs that tower manufactures are
> unable to provide.  I really want to get this little tower up but it
> is like a brick wall.  UST sales people tell me they don't have a PE
> on staff, they contract PE work out to an outside engineer.  I have
> been trying to get 90 MPH wind calcs for months and all I get is the
> PE haven't gotten back to them (UST sales) yet.  I have told them if I
> can't get wind calcs for the MA-40 then what about their TMM-541SS or
> TX-438 or HDX-538.  No answer.
> If you have a used tower and have to hire your own PE to do the wind
> calcs and provide a base foundation drawing for you from scratch it
> may turn out to be an expensive experience.  I hope not but be
> prepared for the worse.
> Hope you have better luck than me.