[TowerTalk] Long cable pull

Larry Burke wi5a at sbcglobal.net
Sat Jul 19 21:43:23 EDT 2008


Jerry, Chuck's comments are dead-on based on my experience. Soap is your
friend, and put a break or two in the middle somewhere using a conduit
fitting. Every 100 ft might be overkill unless you use a fish tape. You
don't have all that many cables in the conduit, so this should not be too

Putting in a pull string (a.k.a "jet line" in some parts of the country) is
actually very simple. I just did this with a 350 ft run of 3" conduit, you
may have to scale accordingly: 

First, you don't want to use any ol' type of string as your pull line. There
is a product made just for this purpose. The  Big Box stores carry it in
smallish quantities and electrical supply houses carry larger boxes. Jet
line is lightweight and strong. It is packaged such that it freely comes out
of the container without knotting, so don't unspool a bunch and lay it out
prior to the pull. As a side note, if your pull is significant (long pull or
lots of cables) the jet line may serve to pull a heavier duty pull line
through the conduit once the jet line has been fully installed. 

Second, get a shop vac and hook the hose up to one end of the fully
assembled conduit run (i.e. all conduit joints glued and covers installed by
this point). Duct tape the shop vac hose to the conduit to minimize air
in-leakage. Make a mouse out of a lightweight plastic bag (I used a Wal-Mart
bag) by wadding the bag up and tying it to the free end of the jet line
that's hanging out of the package. Insert the mouse into the end of the
conduit opposite the shop vac. The mouse should move freely through the
conduit, but provide enough seal to allow the vacuum to suck it through the
line. I used a whole bag on a 3" line; you may want to use half of the bag
for your application. Position the container of jet line such that it is
free to spool itself out without getting hung up on anything. Turn on shop
vac. In a very short time the mouse will arrive at the shop vac and you will
have spooled out lots of jet line. 

A couple of hints: (1) it's best to do this with two people, one at each end
of the run; (2) you may save yourself untold grief by placing a "filter" of
some type over the end of the shop vac hose prior to using it -- an old
nylon stocking or piece of screen works. This should keep you from sucking
the mouse and jet line into your vacuum. 

It's probably obvious, but you don't put the soap in until you have the pull
line in place and are ready to pull in the final occupants of the conduit. 

Larry K5RK

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