We installed underground utilities to a new mall scheduled for completion this summer. Prints called for 2" conduit for CATV and despite my bringing to the attention of the site GC's super the CATV standard calling for larger pipe no OK could be obtained to size it up and get paid for it. End result is a 1200 foot run of 2" with no pull holes (only 2-90 deg bends though).

What is the longest of this type pull you have ever successfully done...think this will fly? The pipe is sufficiently larger than the cable, but the logistics of pulling hard thru 2" are tricky...rope size,etc.

Lack of pull holes was due to sacred "buffer zones" around the project which could not have structures showing. Common here is 4" conduit with pull holes every 4-500 ft. I have the print to protect me but still am concerned about the difficulties the engineering (driven by budgets) has created. The difference in 2 and 4 inch would easily be absorbed by the owners of this project but we couldn't afford to eat it twice(it exists in a slightly shorter form elsewhere on the site).

What kind of pipe was used?

PVC
RIGID METAL
ECT?

Dnk...

Ouch! 2" is a big mistake. Do you even know what cable will be pulled in there? It's going to be flooded hardline (solid sheath) probably nearly 1" in diameter. If someone actually does manage to pull it through I can't see how it will survive without damage.

There is a reason for 4" and handholes. Those stupid engineers think all CATV is RG-6!

-Hal

It's PVC all the way, and yes, I believe the cable would be hardline, it always is. Apparantly the money guy for the tenant's GC for this project came and met with the planner at the local CATV and told him what he had in mind, was clearly told "no way" on 2". A second conversation was had over the phone where the money guy said that's what he had instructed the engineering firm to draw for bid purposes, was again told "no way". At any rate, that's what we carried in our bid(you can't get bid jobs around here by being generous) and I was unable to generate any interest when I started the job. Diggers 200 feet of trench ahead of me and ready to backfill, this ain't the time for engineering.

I never have fully understood the thinking of the non-construction savvy money guys who try to keep the costs down despite expert advice not to cut certain things.

All I want to do is get a mouse thru, pull a 1/4" nylon rope back thru to satisfy our contract.

BTW, I am not the owner, just a tool wearing foreman. These guys don't want to here from me.

If the 2 90s are at the ends they might be better off to cut them out, pull the cable through the straight section and put them back. When FPL pulls long service laterals around here they seldom put in the stub up until the wire is in. Not really Kosher but it works for them.

NO ROPE YET! With 2000' you had better start pulling some in as you go. You might find it really hard to blow, suck or otherwise, get a 1/4 line in. You might be able to suck a 1/6th through, and pull the larger later, buy just a little wetness will wieght the line down.

Seriously, you might want to add some Chisty boxes. They aren't structures IMO.

Your going to need a compressor to blow a line through that far.

A large one....

The type of "mouse" I've found to work the best are the Duct Projectiles

See bottom of page at
www.saftco.com/missiles.htm

Best of Luck to you !

[This message has been edited by electure (edited 06-09-2005).]

Don't you have one of those new 1200 ft. fish tapes. That's the mentality you end up working with. I had a company send out a compressor once ( a small one, wouldn't inflate a bicycle tire) to blow lines with. Then they wanted to pull 930 ft. of 750 with a 1/2" lylon rope. Spent 2 useless days trying in heat of over 100. I figured our loss at about 3k. We were really saving the money. The thing that I can't figure out, is how idiots stay in business. Maybe it's true that God looks out for fools, children and drunks.

We use a used plastic shopping bag for the mouse, and vaccuum in polyproplene string that comes 10,000 foot in a box or bucket. Works like a charm, even with other cables or conductors in the conduit.

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).]