Attaching a pull rope

I was wondering how knot experts would suggest
attaching communication cables to a pull rope in a
conduit.

Criteria:

The pull rope is usually very stiff 3-strand
twisted 1/4" polypropylene. It does not hold knots
well at all, in my opinion.

The cable to be pulled is 6-pair gel-filled
buried drop wire with a diameter of abt 1/2 ". This wire
is somewhat rigid in that it has 12 conductors, a copper
sheathing, and a weatherproof black outer sheath. .
Note: the sheathing can be stripped back to expose the
conductors, and the conductors themselves can be
tied to the pull rope.

The splice between rope and drop has to be as compact
as possible, as the diameter of the conduit is often as
small as one inch, with several "elbow" turns along
the way.

Strength of splice is very important, because this cable
is heavy and when the pull is over 100' there's a great
deal of strain on the joint.

What's normally done is the drop is stripped back and
the a bight of the conductors is formed at the end.
The excess length of the conductors is wrapped around
the sheathing of the drop and taped down w/electrical
tape, so you end up w/a loop at the end of the drop.
The pull rope is the knotted to the loop. What happens
from time to time is the loop pulls out, the knot is too bulky
for the elbows, the knot slips due to the gel and stiffness
of the rope, etc. etc.

Any ideas would be appreciated.

Luke in Ca

wrote in message
...
On Sun, 3 Jul 2005 18:58:02 -0700, "Luke 451"
wrote:

I was wondering how knot experts would suggest
attaching communication cables to a pull rope in a
conduit.

Criteria:

The pull rope is usually very stiff 3-strand
twisted 1/4" polypropylene. It does not hold knots
well at all, in my opinion.

The cable to be pulled is 6-pair gel-filled
buried drop wire with a diameter of abt 1/2 ". This wire
is somewhat rigid in that it has 12 conductors, a copper
sheathing, and a weatherproof black outer sheath. .
Note: the sheathing can be stripped back to expose the
conductors, and the conductors themselves can be
tied to the pull rope.

The splice between rope and drop has to be as compact
as possible, as the diameter of the conduit is often as
small as one inch, with several "elbow" turns along
the way.

Strength of splice is very important, because this cable
is heavy and when the pull is over 100' there's a great
deal of strain on the joint.

What's normally done is the drop is stripped back and
the a bight of the conductors is formed at the end.
The excess length of the conductors is wrapped around
the sheathing of the drop and taped down w/electrical
tape, so you end up w/a loop at the end of the drop.
The pull rope is the knotted to the loop. What happens
from time to time is the loop pulls out, the knot is too bulky
for the elbows, the knot slips due to the gel and stiffness
of the rope, etc. etc.

Any ideas would be appreciated.

Tape up the end of your cable to reduce drag and facilitate making the
elbow turns. Use 500# test parachute cord as your pulling line. Tie it
to the cable with either
an Icicle hitch, http://tinyurl.com/7hmr3
a rolling hitch, http://tinyurl.com/ab7vh
or a, gripping sailor's hitch, http://tinyurl.com/88d5a
If space permits put a layer of tape over the hitch.

I like the icicle hitch idea, but unfortunately I'm stuck with the
1/4" polypropylene. Contractors leave this stuff in the conduit
long b4 I show up. It's hard, provides little friction, and does
not hold a knot well. The knot tends to expand a bit due to
the stiffness and loses some of its effectiveness. You think
this would work with the slick black sheathing of the cable
and the stiff pull rope?

This brings up another question: why is this polypropylene
rope so popular? I realize it floats, but that doesn't explain
its ubiquity. Out here in NoCal, USA, every other pickup
truck has bleached out lengths of it tied to the cleats, with
the ends unraveled and frayed up the last foot of its length.
Am I missing something? Isn't this the worst stuff you can
choose to tie anything down?

Luke in Ca

On Tue, 5 Jul 2005 06:39:54 -0700, "Luke 451"
wrote:


I was wondering how knot experts would suggest
attaching communication cables to a pull rope in a
conduit.

Luke in Ca


hi Luke,

the icicle hitch or gripped sailor hitch might work in polypropylene
line (the rolling hitch will not)
may be in combination with this suggestion:
Use a heat gun or hair drier to fuse the knots. Hold the knot tight
with fingers a couple or more inches from the knot and heat the knot
area until you see an outside fiber pop up; the knot will be fused,
soft, and remain tied and fused when it cools and hardens.
found at:
http://www.bamboofencer.com/s.nl/sc....d.105/KB.76/.f

a pull tape can be used and that gives more room for a knot and more
surface for grip
http://www.neptco.com/website/neptco...6?OpenDocument
with a few knot suggestions:
http://www.arncocorp.com/pdfs/pulltapebro.pdf
http://www.neptco.com/website/neptco...0Tips?OpenView
(links found in an earlier thread "dandy-line" in this newsgroup)

if it is three strand rope, I would go for a chain spice
http://www.neropes.com/splice/sp72_3...d_to_chain.htm
it is compact and strong and easy to learn and smooth and looks good
but it takes some time to do

knot a knot suggestion,

Ben

Luke 451 schreef:

This brings up another question: why is this polypropylene
rope so popular? Isn't this the worst stuff you can
choose to tie anything down?

Luke in Ca

cheap polypropylene is popular, and with polyethylene, it is the worst
stuff ...

"Both PP and PE can be found in many forms, shapes and qualities. The
quality of cheap, general available PP and PE is quite often poor. UV
stabilizer (expensive component) is not added at all or only in very
small quantities"
http://www.lankhorst-touwfabrieken.n...20and%20PE.htm

well, knot nessecarily,

Ben

On Sun, 3 Jul 2005 18:58:02 -0700, "Luke 451"
wrote:

I was wondering how knot experts would suggest
attaching communication cables to a pull rope in a
conduit.

Maybe you should ask conduit-pulling experts. I have
just watched as over twenty miles of conduit in our
new house was filled with everything from 500kCM
(thumb-sized copper) down to 2 pair, 28 ga wire.

The electricians here made a loop in the end of
the pull cord (often just an overhand knot around
the standing part, with the bitter end taped along
the standing part with electrical tape. The wire
was fed through the loop and twisted to itself
and the whole joint was taped over starting at
the wire and ending up on the pull rope so as
to have the overlaps facing the right way.

If the wire was large, the conductors were exposed
and twisted to themselves; if the wire was small,
the whole wire, including insulation was twisted
to itself. The one thing that ALWAYS happened
was greasing the line to be pulled. They used
a white grease from Greenlee designed for lubricating
pulled wire. The lead electrician (over 40 years
in the trade) said this was essential, even though it
made pulling into a pretty nasty job.

On thing they NEVER did was pull wire unsuited for
the purpose. You say you are pulling buriable
drop wire through conduit? You may need to provide
a much larger conduit or a much more flexible cable.


--
--Pete
"Peter W. Meek"
http://www.msen.com/~pwmeek/

On Sun, 3 Jul 2005 18:58:02 -0700, "Luke 451" wrote:

I was wondering how knot experts would suggest
attaching communication cables to a pull rope in a
conduit.

I'd like to have the materials in hand in order to better
respond to this. Knots behavior is material dependent.

Criteria:

Thanks for the details!

The splice between rope and drop has to be as compact
as possible, as the diameter of the conduit is often as
small as one inch, with several "elbow" turns

This is quite a tight fit--2/4 + 1/4 leaves a scant 1/4 from the
tightest enclosure, and as for making right-angle elbow turns,
whew, I don't really see that so well!!

elbow turns. Use 500# test parachute cord as your pulling line.

This isn't necessary: one coul use the parachute (or other strong,
fine, compressible) cord at a connector between the (cheap & present)
pulling line & cable. In fac, it might be that one would get something
like the parachord but then remove the core so as to increase the
cord's ablity to flatten; then one would fashion an attachment
structure from it. But I think that the full cord should work pretty
well.

to the cable with either
an Icicle hitch, http://tinyurl.com/7hmr3
a rolling hitch, http://tinyurl.com/ab7vh
or a, gripping sailor's hitch, http://tinyurl.com/88d5a
If space permits put a layer of tape over the hitch

Another idea is to whip the PP rope about 18" or so from its
working end, then unlay the rope to that point so as to yeild
a trio of strands (each a third of the 1/4" rope dia.) to make
your joint with. The strands could be half-hitched and wrapped
to fashion a "stopper" akin to what Yale markets as YaleGrips:
http://www.yalecordage.com/html/indu..._grip-old.html

E.g, one might incorporate some sort of hitch series. Cf.:

http://storrick.cnchost.com/Vertical...nderKnots.html

This brings up another question: why is this polypropylene
rope so popular?

It's CHEAP, pretty strong, colorful, moderately tough.
(And it comes in a variety of formulations.) Copolymer
rope--blend of PP & polyethylene--has greater strength
& abrasion resistance (or so it's claimed), and has made
inroads in commercial marine use.
But for cable pulling, what I see in the Washington D.C.
area has been cited above by Ben, polyester tape (Neptco,
i.p.). This is lubricated (slippery/slimy feel--comes off
on fingers, e.g.), and usually 1800# test, white with
foot markers on the tape, coming in a couple of widths.
(There is some straw-colored Kevlar tape, too.)

--dl*
====

Thanks to all for yr great ideas.

I've decided the
best way to deal with the problem is to use the lousy
pull rope to pull in an appropriate one, like polyester
tape as suggested. Then the tape shld be able to grip
the drop with a good icicle hitch. I'll tape off the icicle
so it doesn't loose its integrity in the elbows as
it gets scraped against the inside of the turns. The lube
idea is good too; messy, but it beats blowing in a new
tape.

Thanks again for all your insights.

Luke in Ca