[TowerTalk] Tower Failure Radius

[T. A. Russell]

On Fri, 4 Apr 97 04:34:03 UT "Joe Spinosa" <Spinosa@msn.com> writes:
>Hi Roger,
>
>I can tell you that when I applied for a permit to erect a tower in my 
>city, 
>part of the reason they denied it was that they felt that if it ever 
>collapsed 
>it could/would destroy neighboring property.
>
>In fact, they wanted a huge margin.  If the tower was going to be 50 
>feet 
>tall, they would want at least 75 feet of clearance in all directions.
>
>This notion has physically been shown to be false.  I can't remember 
>the exact 
>specification, but its something like 33% of the height of the tower.  
>In 
>other words, a 50' tower should fail/fall into a circle about 17' in 
>diameter.
>
>I'm not an engineer, but that's what I'm told.
>
>I think the numbers are important to show municipalities like mine, 
>because 
>it's one of those aspects of engineering that seems to be 
>counter-intuitive to 
>the lay-person.
The 2000 ft tower collapsed on itself because of a structural failure
within the tower, much like when they demolish buildings by blowing
out the support members.
 
Best Regards,
Joe Spinosa
KF6CWX
Concord, CA

Reply from N4KG:

With an ANCHOR failure, the tower will fall over, most likely extending
to it's full height.

With a guy wire failure, numerous possibilities present themselves.
For  short towers with a single set of guys, it will likely fall over, to
it's 
full height.  With multiple sets of guys, it may buckle out at a mid
point 
or fold over at some mid point, depending on which guy failed.

de Tom N4KG

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