Gerald,
Thanks for the clarification on the Big Grips. Very helpful. I'm happy to
stick with the Rohn/Radian spec.
The Rohn 3/8" heavy-duty thimbles I have don't appear to need the legs
spread to go through the turnbuckle eye. The opening is large enough. The
problem is that the legs are too thick. I can see that a little persuasion
with a hammer might make a leg go through the eye, but it doesn't look like
the thimble would move very easily once the leg goes through. I'm not even
sure it could be rotated to the right orientation (in line with the guy.)
Even if it could be twisted in the right direction, it wouldn't move freely
after that. Isn't it better for the thimble to be able to float freely
within the turnbuckle eye?
You recommend a 1/2" shackle, while Frank says a 3/8" shackle would be
ideal. Do you see any problem with using a 3/8" shackle for my terminations?
73, Dick WC1M
> -----Original Message-----
> From: TexasRF@aol.com [mailto:TexasRF@aol.com]
> Sent: Saturday, September 02, 2006 10:50 AM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Rohn 55 thimbles and turnbuckles
>
>
> Hi All, here is a bit of clarification on the Big Grip and
> thimble size
> issues:
>
> Rohn does not make Big Grips; Preformed Line Products Co.
> makes them and sells them to Rohn. 1/4" EHS uses a BG2144.
> All BG2144 grips are the same design whether purchased
> through Rohn/Radian or other distributors, such as Texas
> Towers. There are other grips made for utility use that fit
> 1/4" EHS but they are shorter, have fewer strands and not
> recommended for tower guy applications. These other grips
> will not be identified as Big Grips.
>
> For the 1/4" Big Grip, BG2144, Preformed Products calls for a
> 1/2" thimble and Rohn/Radian calls for a 3/8" heavy thimble.
> The groove in these two sizes have the same dimension so it
> makes sense that either a 1/2" regular thimble or a 3/8"
> heavy thimble will work fine. Texas Towers carries the heavy
> series because this is the size recommended by Rohn/Radian.
>
> A 3/8" heavy thimble is a very close fit into the eye of a
> 1/2" X 12 turnbuckle. Once the legs are twisted apart, it
> takes only a slight "persuasion" to push the thimble through
> the eye of the turnbuckle. If this seems like too much effort
> then by all means a 1/2" shackle can be used to connect the
> thimble and turnbuckle. Texas Towers has these shackles in
> stock as they are required when connecting Phillystran
> grips/thimbles to turnbuckles and other hardware.
>
> Joining Phillystran to EHS can be done by back to back
> thimbles or with shackles.
>
> 73,
> Gerald Williamson
> General Manager/Texas Towers
>
>
>
>
>
>
> In a message dated 8/31/2006 6:22:47 A.M. Central Daylight
> Time, donovanf@starpower.net writes:
>
> Hi Dick,
>
> It seems unlikely that Rohn makes preformed Big Grips.
> Preformed specifies use 1/2 inch heavy duty thimbles. The
> cost isn't much higher than 3/8 inch heavy duty thimbles.
> The only way to resolve this is to communicate directly with
> engineers at the companies involved...
>
> You would probably regret fastening Big Grips (and
> thimbles...) to the guy attachments without use of shackles.
> As you point out, it would be inconvenient to remove the guys.
>
> 3/8 inch shackles are an ideal match to the load capacity of
> 1/4 inch EHS guy wire (5/16 inch shackles have a breaking
> load capacity of 6600 pounds, slightly less than the
> breaking load capacity 1/4 inch EHS). In my previous e-mail
> I recommended that you use 7/16 inch shackles; however, their
> 13,300 pound breaking load capacity in unnecessarily large
> for your guy system.
>
> Good luck with your new tower installation Dick!
>
> 73!
> Frank
> W3LPL
>
> ---- Original message ----
> >Date: Thu, 31 Aug 2006 03:19:45 -0400
> >From: "Dick Green WC1M" <wc1m@msn.com>
> >Subject: Re: [TowerTalk] Rohn 55 thimbles and turnbuckles
> >To: <donovanf@starpower.net>, <towertalk@contesting.com>
> >
> >Frank,
> >
> >Glad you weighed in on this.
> >
> >I got 1/2" thimbles for the Preformed Grips I'm using with
> the 6700 lb
> >Phillystran -- as specified on the Texas Towers website. So
> far, so good.
> >
> >But I ordered 3/8" heavy-duty thimbles for the 1/4" EHS
> bottom leaders
> >because that's what Rohn specifies for use with their 1/4" EHS Big
> >Grips (part # BG2144.) Here's a link to the parts list in
> the Rohn catalog:
> >
> >http://www.antennasystems.com/PDFs/ROHN/55G/55G-14.pdf
> >
> >I'm using 6700 lb Phillystran with 1/4" EHS leaders on all
> three guys,
> which
> >isn't quite up to the 110 MPH spec (the top guy is supposed to be
> >5/16"), but exceeds the 90 MPH spec. The parts list shows
> BG2144 grips and 3/8"
> >thimbles for the 1/4" EHS. Is there a difference between Rohn Big
> >Grips and Preformed Big Grips?
> >
> >Do you think the Rohn-specified 3/8" thimbles are OK for their 1/4"
> >EHS grips? If so, would you still use a 7/16" shackle, or
> something smaller?
> >What's a good source for high-quality shackles? Would you
> recommend
> >using shackles to connect the 1/2" thimbles at the end of the
> >Phillistran grips to the solid links on the GA55GD guy
> brackets? Here's
> >a diagram of the
> bracket:
> >
> >http://www.antennasystems.com/PDFs/ROHN/hardware_accessories/
> HA-79.pdf
> >
> >The 1/2" thimble should fit inside the loop OK, but a
> shackle would
> >make installation and removal easier.
> >
> >73, Dick WC1M
> >
> >-----Original Message-----
> >From: donovanf@starpower.net [mailto:donovanf@starpower.net]
> >Sent: Wednesday, August 30, 2006 9:00 PM
> >To: towertalk@contesting.com
> >Subject: Re: [TowerTalk] Rohn 55 thimbles and turnbuckles
> >
> >Dick,
> >
> >1/2" heavy duty thimbles are required by Preformed Line
> Products for use
> >with their Big Grips for 1/4" guy wire and Phillystran.
> >
> >See:
> >http://www.preformed.com/artsfest/files/AppProc/SP2049-3.pdf
> >http://www.preformed.com/artsfest/files/AppProc/SP2806.pdf
> >
> >Use a 7/16" shackle to make the transition from the thimble to the
> >turnbuckle.
> >
> >73!
> >Frank
> >W3LPL
> >
> >---- Original message ----
> >>Date: Wed, 30 Aug 2006 19:47:29 -0400
> >>From: "Dick Green WC1M" <wc1m@msn.com>
> >>Subject: [TowerTalk] Rohn 55 thimbles and turnbuckles
> >>To: "Tower" <towertalk@contesting.com>
> >>
> >>Reviewing the Rohn parts list for a 110? 55G tower @90-100MPH, I
> >>decided to go with ¼? EHS for all three levels (actually, 6700lb
> >Phillystran with ¼?
> >>EHS leaders. Following the parts list, I ordered 3/8? heavy-duty
> >>thimbles
> >>(3/8THH) and ½?x12? eye-jaw turnbuckles (1/2TBE&J). Rohn specifies
> >>that the thimble should be one size larger than the guy
> diameter. The
> >>parts have arrived, and I?m perplexed to find that the
> 3/8? thimbles
> >>don?t fit inside the eye part of the turnbuckles. I might
> be able to
> >>make them fit by flattening the edges of the thimble a bit
> >>(sandwiching it between a piece of two pieces of flat steel and
> >>hammering the flare out of the edges), but before I try that, I?d
> >>like opinions on this. I can?t be the first person who has run into
> >>this. It looks like a shackle would work, but Rohn doesn?t
> specify them for 55G towers. Comments?
> >>
> >>
> >>
> >>73, Dick WC1M
> >>
> >>
> >>
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> >>
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