[Towertalk] Inquiry - Tower Collapse/Fall/Radius Zone

[Bill Coleman]

On 4/9/02 9:29 AM, Dan Evans at n9rla@yahoo.com wrote:

>The annoying part of that is, every tree I've ever seen fall, fell it's full
>height.  But no one is restricting the height of trees. 

Actually, when a tornado went through my neighborhood in 1988, the fallen 
trees almost never fell their full height.

Instead, they were snapped off at about 12-18 feet off the ground.

The one incident of a tree falling out to its full height was a 
neighbor's tree that leaned over to one side after many, many days of 
rain waterlogged the ground, and caused the roots to pull out. That one 
failed about 2-3 feet BELOW the ground.

I don't think below ground failures are likely for proper tower 
installations. Failures 10-20 feet off the ground are more likely. Towers 
(and trees!) are awfully strong right next to the ground.



Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr@arrl.net
Quote: "Not within a thousand years will man ever fly!"
            -- Wilbur Wright, 1901