[TowerTalk] Collapsed KFI Tower -- Impact of Coax?

[Tower]

>
>

Hmmm... I think I see the problem.
>>
>>

The above sentence is *supposed* to be:
 Even tall, unguyed structures tend to fall in on themselves although they
 would'nt form a close a knit pile as the guyed tower.

No, it wouldn't form a pile at the bottom.  It most likly would not all full 
length, but most of it would be laid out in a line.  Well, there's only two 
letters and one punctuation mark.  It was close. <sigh>

73

Roger Halstead (K8RI, EN73 & ARRL Life Member)
N833R, World's Oldest Debonair (S# CD-2)
www.rogerhalstead.com

>
> I don't know that this statement is true. Unguyed structures tend to lay 
> out
> flat (kinked, it's true, but the final position is usually laid out).  If
> you have some analysis that shows otherwise, I'd love to see it (because
> this question comes up a lot).
>
>> The acelleration of a tall tower tipping over will cause the top half of
> so
>> to bend back on itself.
>
> This is indeed the case (and, interestingly, it also happens when a pencil
> point breaks). It's particularly noticeable on masonry columns 
> (smokestacks
> are a good example), as they break into segments on the way down. 
> However,
> they don't collapse in a heap at the bottom, they just flex and break.
>
>>
>> I'd sure hate to have the liability of a tower near final approach to any
>> airport.
> That tower has been there for >50 years and only been hit once before (a 
> guy
> wire strike, I believe).  It's well marked on the charts, and granted, 
> it's
> hard to see in the daytime, but, then, that's why it's on the charts. 
> There
> are worse hazards near airports. Hills off the end of the runway, stuff 
> like
> that. Power lines across canyons. All those places where the approach 
> plate
> says "successful go-around unlikely".  In the LA Basin,  I'd worry more
> about hitting another plane or busting some controlled airspace boundary
> because you were talking to the wrong controller on the radio and getting 
> a
> nasty note from the FAA.
>
> Since the tower was there before the airport, there's not much liability
> that attaches to its continuing existence.  Whether it was a good idea to
> build parking lots and industrial space underneath it is another question,
> but from the photos I've seen so far, the damage to surrounding structures
> is limited (if any). So far, it looks like the engineers did a decent job
> (after all, having an airplane fly into your tower is a fairly unlikely
> occurance).
>
> There has been some bickering mentioned about why there weren't strobes on
> the tower.  (Maybe Clear Channel doesn't want to spend the bucks?)
>
> And, it used to be a LOT easier to see from the air, because it was in the
> middle of this huge vacant lot, which sort of stood out as you followed 
> the
> I5 freeway north or south (the classic IFR (I follow roads) technique).
> Personally, I preferred flying a bit farther east (under the controlled
> airspace) or west (over the coastline).  These days, you'd have to watch 
> out
> for the Disneyland prohibited airspace (if it's still in force).
>
>
> Jim W6RMK
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
> Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with 
> any questions and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
>