[TowerTalk] tower restrictions

Michael Keane K1MK k1mk at alum.mit.edu
Sat Jul 19 10:34:11 EDT 2008

At 07:40 AM 7/19/2008, Martin Staffa wrote:
>I have been going back and forth with the town first it was a permit 
>then it was no good they pulled it before I could even dig the 
>hole.Then it went to town attorney for review,came back must give 
>reasonable accommodation.went back for a permit the town engineer 
>wanted to see specs on tower.He then determined the tower did not 
>meet wind shear for my town.110 mph at three seconds tower is 70 mph 
>will not issue a permit. Started this project July 12 2007! Town of 
>Northbranford Ct.

North Brandford was never a 70 mph wind zone under the earlier 
"fastest mile of wind" measure for basic wind speed (EIA/TIA-222-E; 
ASCE 7-88); North Branford was a 85 mph fastest mile of wind zone. 
Proposing a 70 mph design for an 85 mph zone was poor planning. It's 
not the town engineer's fault for noticing that deficiency.

For the two measures of wind speed, a 110 mph three second gust is 
approximately equivalent to a 90 mph fastest mile. With the other 
technical changes in how wind load calculations are performed, a 85 
mph fastest mile compliant design may satisfy a 110 mph 3 second gust 
with no changes.

By and large, tower manufacturers have not updated their literature 
and specifications to the latest standards. Check the fine print and 
the footnotes on the drawings. IN applying for a building permit, the 
burden is on the applicant to demonstrate compliance of teh proposed 
design with the current building code. If the manufacturer does not 
provide the necessary data, one must be prepared to employ the 
services of a local PE to perform the necessary calculations.

With zoning and building codes, everything is local; generalizations 
tend to confuse the issue and send first-timers off on unproductive 
tangents. You simply have to know your local zoning rules, you have 
to know your state and local building codes. If you don't want to 
take a time to learn them, hire professionals to do it for you.

Mike K1MK

Michael Keane K1MK
k1mk at alum.mit.edu

More information about the TowerTalk mailing list