[TowerTalk] [Bulk] Re: Rotating tower guying question

[Grant Saviers]

I agree with KK9A.  I think the Philly will outlast EHS if installed and 
treated properly.  At least I plan so in re-using about 1200 ft 
recovered with a 140' R65 AM radio tower I'll be erecting in a three 
weeks.  The tower needed to be regalvanized as it was just starting to 
show surface rust.  The Philly looks perfect.  Since this was pre 1995 
or so parallel strand Philly, I used Spelter sockets and epoxy to 
terminate the ends (see my article in Nov/Dec 2014 NCJ about this).  
Cable clamps will not work reliably on any Philly and current guy grips 
also won't work on the old Philly.  I suspect the galvanizing on the new 
guy grips are the life limiting factor.  A test section of my "old" 
Philly with Spelter terminations was tensioned to destruction on a test 
stand and failed right at original spec - 26,000 lbs.

Abrasion and water inside that freezes are the enemies of the PE cover.  
The Kevlar doesn't have great fatigue life but is probably better than 
EHS, so torque bars are likely a good idea on all towers that rotate or 
have large antennas.  It also has poor abrasion resistance, so a branch 
that rubs thru the PE rapidly abrades the Kevlar.

EHS is often recommended as a bottom section as wild fire and vandalism 
protection.  However, any fire will anneal the heat treating of the EHS 
and it should be replaced.  Since the Spelter sockets are not field 
adjustable, I use a short EHS bottom section so the guys can be "cut to 
length" when the tower is erected.

Grant KZ1W

On 5/3/2015 19:00 PM, john at kk9a.com wrote:
> I have never done the calculations but I would be surprised if EHS was that
> much cheaper than Phillystran after you add in the cost of all of the Big
> Grips and insulators. If you also add your time EHS is likely the most
> costly option. In my experience the lifespan of Phillystran is more than
> EHS, especially in a corrosive environment. Another non-conductive guy
> option is Polygon Rod.
>
>
> John KK9A
>
>
> To:	"<towertalk at contesting.com>" <towertalk at contesting.com>
> Subject:	[TowerTalk] Rotating tower guying question
> From:	Andre VanWyk via TowerTalk <towertalk at contesting.com>
> Reply-to:	Andre VanWyk <kr5dx at yahoo.com>
> Date:	Sun, 3 May 2015 18:07:48 -0500
>
>
> I am about to start construction on my new 165ft Rohn 55G rotating tower. My
>
> anchors are 180ft out from the base.
>
> My question is: Just how much is using Phillystrand cable buying me versus
> using EHS cable broken up with insulators?
>
> I don't want to cut corners on this installation but the cost on the EHS is
> far
> lower than Philly and I am sure the lifespan is much longer too.
>
> How about using Philly for 50% out from the tower bearings and then EHS for
> the
> remaining 50% down towards the anchors?
>
> Any comments / thoughts would be appreciated.
>
> 73's
> NJ0F
>
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