Another consideration, that makes Philly different from EHS, is the
black color of the jacket. My experience, having used
Philly in the past in areas prone to ice storms, is that the black color
absorbs sunlight better and melts the ice off a lot faster
than occurs on EHS cable. I had a tower with philly and the preformed
grips up for about 10 years and never had trouble
of the sort you're talking about, and we had ice storms there (central
MO) almost every winter, usually several times.
Alan Braun NS0B
Dick Green WC1M wrote:
> Excellent question. I wondered about that myself when I installed my
> Phillystran guys.
> Seems to me if the cable is properly tensioned, there won't be a lot of
> flexing at the end of the grips, so there won't be much chance the grips
> will unravel. I would imagine the primary issue would be ice forming on the
> cables, then sliding down and slamming into the end of the grip. Rohn sells
> metal sleeves with their EHS grips that you tap over the ends of the grip to
> guard against this. I put them on the upper ends of my EHS leaders, which
> are now out of reach, but have yet to get around to putting them on the
> bottom end of the leaders, where it would matter the most. While the metal
> sleeves make sense, I would think nylon cable ties wouldn't do much to keep
> a Phillystran grip end together if a chunk of ice slammed into it. I think
> the tie would just slip down the grip. I wonder if ice is less likely to
> form on Phillystran than EHS. Does anyone know?
> The nylon cable ties appear to be made of UV-resistant material, so they'll
> probably last longer than regular ties, but not forever.
> However, I question whether the ties provide any real protection from the
> grip unraveling. Though I pulled the ties as tight as I could, I had
> problems with them slipping off when I transported the cables from my garage
> to the tower site. Just normal flexing of the grip and cable during
> transport caused this. I slipped the ties back in place. Like I said, if
> there's enough force from falling ice to unravel the end of the grip, I
> think the tie will just slip back away from the end. BTW, half my
> Phillystran grips are at the interface between the Phillystran and EHS
> leaders, so I can't reach them to substitute hose clamps. Those are the
> grips that might need protection from falling ice -- the ends of the grips
> attached to the tower face down, where ice can't slam into them.
> Hose clamps would probably be more likely to stay in place than plastic
> ties, but I'd be concerned about the clamp distorting the strands of the
> grip, or worse, the Phillystran. Also, you don't want the sharp grip ends to
> penetrate the delicate Phillystran jacket. It might be difficult to tighten
> the clamo enough to hold the grip ends together but not cause problems with
> the cable. I have a feeling this is why Preform doesn't supply metal sleeves
> with their Phillystran grips: pushing the metal sleeve onto the end of the
> grip could cause the strands to damage the cable. Same might happen with
> hose clamps.
> Bottom line, I would use the ties and not hose clamps. Hose clamps are not
> specified by the manufacturer, and there's may be a good reason for this.
> Also, it would violate the 'LXC prime directive: always follow the
> manufacturer's instructions.
> 73, Dick WC1M
>> -----Original Message-----
>> From: Scott Dickson, W5WZ [mailto:W5WZ@arrl.net]
>> Sent: Saturday, August 30, 2008 1:42 PM
>> To: firstname.lastname@example.org
>> Subject: [TowerTalk] Phillystran and preformed grips
>> Phillystran instructions indicate placing a single nylon 'zip tie' one
>> from the ends of the short leg of the grip.
>> Should I worry about the longevity of the nylon zip tie when exposed
>> to the
>> Would a better solution be to use a small stainless steel hose clamp,
>> or at
>> the very least a cable clamp?
>> --Scott, W5WZ
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