I did this recently. In both cases, read and reread the manufacturer's
instructions. They do make sense after you read them several time.
The most important thing I found out about installing Philly grips is that
you MUST wrap the two legs together. With EHS grips, you can wrap one leg
all the way to the end, then wrap the other one. That will not work with the
Philly grip. Due to deformation of the Philly material, you won't be able to
wrap the second leg. If you try, you'll mangle the grip. You can wrap a turn
or two with one leg, then you must go back and wrap the other leg. I found
that once you get it started, you can hold a leg in each hand and wrap them
together -- hand-over-hand, sort of like making a braid. BTW, that works
fine with the EHS grip, too. In fact, I prefer doing it that way because
it's a little faster.
It's possible to wrap an EHS grip without putting any tension on the cable,
but you really have to put tension on the Philly. I precut the lengths with
a foot extra at each end, then clamped the thimble end in a vice and applied
the grip and thimble a little ways down the cable from the vice. I had a
friend pull the cable taut about five feet further down, and wrapped the
grip. Then I cut off the excess Philly so the end of the cable wound up
inside the thimble. This removed the portion of the cable that had been
under pressure in the vice jaws. I just discarded that small piece of
Philly.
Be sure to start the wraps at the first set of colored marks on the grip.
Sometimes the ends of the grips come together easily with a snap and lay
nice and flat. Other times a strand or two will get out of place and you'll
have to push it into position with a screwdriver. Just make sure the strands
are all in the right order, are not on top of each other, and lay flat.
Buy the correct size grip for the size cable you are using, and buy correct
thimble size and type (heavy duty!) for the size grip you are using. The
Rohn catalog has sizes for EHS cable. You can get the thimble specs for EHS
and Philly from the Preform website. I followed the Rohn catalog and used
3/8" Heavy Duty thimbles for the 1/4" EHS. I followed the Texas Towers
recommendation and used 1/2" Heavy Duty thimbles for the 6700lb Philly. The
Heavy Duty part is very important. Regular galvanized thimbles won't fit,
and even if you buy a size that does fit, they won't hold up in use. You
will probably need shackles to connect the big 1/2" thimbles on the Philly
to the guy brackets on the tower, and may need them at the EHS/turnbuckle
interface as well.
Hope this helps. Feel free to ask more questions.
73, Dick WC1M
-----Original Message-----
From: duxburyn@bellsouth.net [mailto:duxburyn@bellsouth.net]
Sent: Thursday, June 14, 2007 4:00 PM
To: towertalk@contesting.com
Cc: duxburyn@bellsouth.net
Subject: [TowerTalk] Big Grips
I'm about to guy my two new towers using Phillystran with protective
segments of 1/4 in. steel cable at the ground anchor ends. This will be my
first experience with Big Grips and that's where I need some help. I have
the manufacturer's instructions, but they're a bit vague and the photos are
not clear. What I need are some hints and kinks about using Big Grips with
both Philly and steel; helpful things that you have learned from
experience.
Thanks and 73,
Norm, W1MO
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|