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Mast Strength

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Subject: Mast Strength
From: (
Date: Tue, 3 Dec 1996 12:27:03 -0500
In a message dated 96-12-02 15:03:54 EST, you write:

>       In the past, there have been a lot of comments about not using water
>pipe as a mast.  
>       Tower #1:  mast is 2" schedule 80 water pipe
>       Tower #2:    mast is 2" schedule 80 water pipe
>       I am located about 10 miles air distance from Plymouth Harbor in
>Massachusetts.  (Perhaps you could tell me the wind figures for this area 
>Steve K7LXC?)
>       There has never been any damage to any of my masts during these and
>numerous lesser storms of 40 or 50 MPH.  Any ideas as to why not?

Hi, Dave --

    You post made me real nervous.  You are lucky.  No, let me rephrase that.
 You are DAMN lucky.  It just goes to show that everytime you speed you don't
get a speeding ticket either.

    You have what we call in the trade "a disaster waiting to happen".  If
you're in Plymouth County, it is a 95 MPH wind speed zone and also less than
100 miles of a hurricane oceanline.  Everything you have should be built to
that spec or greater.  You must have a lot of trees around you shielding the
wind is the only reason why I figure you have been able to dodge the bullet
so far.

    I think that you have survived (beside the trees) because the 20M
Cushcraft antenna you're using will do the well-documented Cushcraft/Force 12
 element dance in the wind.  That is, the antenna is limber enough that it
sheds a lot of the wind force by moving around.  Bend like a willow rather
than break.

    No tower or antenna builder or engineer would have ever suggested using
the pipe for masts for your installation but you've been lucky.  Just make
sure that your homeowner's insurance is paid up.  

73,  Steve  K7LXC

    TOWER TECH - professional tower supplies and services for amateurs

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