ECN Forum Forums General Topics of the Trade General Discussion Area Long pull

The problem you could run into is the string or small dia. roope cutting into the PVC 90
and stopping you dead in your tracks. I've seen it happen. Most of us have at least seen it happen where the string cuts into a TA and plastic bushing....the same can happen in the elbow on a long run. Solution is to replace PVC 90's w rigid 90's Good luck.
Z...

[This message has been edited by zero76 (edited 06-10-2005).]

Would long sweep 90s or even 45s and coming out of the ground at an angle be options here? Not suggesting this as someone who as dealt with long pulls, but asking those who have done so if this would help or not.

-Jon

I have been on lots of long pulls. Yes, anything you can do to reduce the degree of bend in the conduit or the friction helps. The amount of drag or friction created by that first factory 90 is great. Wire lube helps some. Also as someome mentioned, the nylon rope is going to cut into that last 90 from the time the pull starts. PVC 90's and nylon ropes don't work well on long pulls. 45's on the end would be a lot of help, if it would work out for termination purposes. When the guys come to pull the cable and see that small pipe they are likely to start with a bad attitude. It's the cable that will suffer from the stress of a hard pull. It's better if the same crew that ran the conduit pulls the cable, they know more of what they are dealing with and to be carefull. The real issue here is that it will probably cost more over time by using this smaller PVC.

While I tend to believe that cables pull harder in smaller conduits, I have yet to see the conduit diameter enter into any of the pulling force formulas that I have seen.
Look at this .
Don

I'd like to see the money guy's face when the CATV company tells him that the conduit does not meet their spec, and that they will not pull cable unless the conduit run is replaced.

1200 Feet ? 2" ?
The rope will burn through those pvc 90's before the wire eaze even gets to them !
I think gfretwell is right about taking at least one 90 off. you might be ok with the 90 on the end you are feeding from, but the rope might burn through the second 90 before you get the wire pulled and you will end up removing it anyway.

I have never used Muletape , it is said to prevent the cut through of PVC raceways.
Don

The conduit run in question is at the following stage of completion: On the street end it is not terminated at the pole yet because the original plan called for it to go to a pole roughly 800 feet from the building it served. The main entrance to the mall was redesigned making it necessary to remove this pole. The new target became a pole 300 plus feet away. They designed a concrete pull hole for the primary power, but none for the tel. or CATV. I have encouraged them to add these pull holes. Also, the 90 degree sweep at the pole will be rigid steel, as will the pole riser. The building end sits at the bottom of an excavated area inside the building awaiting completion by me early next week. When I do so, I will install a rigid steel 90 and stub thru the slab with steel.

Glad for the input here while I still had time to use it. Thanks and I'll keep you advised.

BTW, the cable guy was on site yesterday and said he just successfully pulled a 700 foot run on another job(not in 2" though).

Took just 10 minutes to successfully blow a mouse thru the 2" conduit today. Blew a lot of water out the 10 foot steel riser at the street pole, will pull a 1/4" nylon rope in tomorrow to allow CATV to pull a larger pullrope in when they are ready. They have agreed to pull the hardline in if the GC supplies some of the special wirelube they requested, supposed to be much more slippery than the stuff we normally use(we use the blue stuff or the yellow stuff)

Then I proceeded to try and suck a mouse thru the 4" tel conduit. All kinds of water and after 3 hrs we gave up and will resume tomorrow with a Greenlee vac blowing on one end and a shop vac sucking on the other end. We had good luck for the first 5-600 feet and removed lots of water with only the Greenlee but are stopped there.

This is what I hate about winter in Maine...digging shuts down in Nov or Dec and resumes in spring. The nice empty conduits get water in them sometimes and create a lot of extra work.

By the way, both runs are actually about 1000 feet.

Before getting carried away we pulled the mouse out and tried a plastic bag. The Greenlee vac was moved out to the pole end and fed with a generator, and the small plastic bag(about 12 X 16 inches) was tied on at the other end, taped securely, but not balled up or anything, and whizzed thru in less than 10 minutes.

I had done this on smaller, shorter pipes, but was happily surprised at how easily it put this project to bed.

It is important to note that we first had to suck out enough water to feel air moving thru the pipe...this was done yesterday with the mouse and vac, and even though the mouse wouldn't go all the way(we concluded there was a flattened hot box bend), it helped us push a lot of water out. Once there was a way for the bag to get by the water it was easy.

[This message has been edited by poorboy (edited 06-29-2005).]

[This message has been edited by poorboy (edited 06-29-2005).]