atcomsystems.ca/forum Forums Telephone Services Outside Plant OSP Construction Duct capacity

I'm installing new voice/data to a building appx 200' away from existing building. A trenching contractor is going to do a directional bore and provide PVC duct.

I need to pull a 50-pair PIC and 6-strand outdoor-grade fiber through new PVC duct. What size duct should I ask for? I guess 3" should be good, no?

2" would do the job and 3" will give you plenty of room for latter pulls

.......and put in an innerduct to pull in that fiber. It is to protect the fiber from crushing caused by the PIC. Pull in the PIC and innerduct at the same time...fiber to follow.

But to answer your question....3" for sure. Industry standard is 4".

One of the things we used to do, was to pull innerduct in to the pipe first and fill it (3 @ 1" or 1.25" innerducts in a 4" conduit).

Later the duct was available for multiple pulls without worrying about damaging the other cable.

We also used that "sock" stuff (soft, multi section duct whose name I can never remember)

Sam

I think the "sock" that Silversam is talking about is "Maxcell". Also, Berk-Tek and Optical Cable Corp. both make outdoor fiber that is tight buffer if you don't want to mess with terminating loose tube fiber.

Maxcell it is. I could never remember the name.

Sam

Yep, we have also used Maxcell.
Good stuff.

Thanks everyone! I like the idea of an interduct pull with the pic. Do you think 3" duct is ok for 50-pair pic and a 1.25" interduct? The duct is going to be about 275' in length, in more or less a straight line, with a 90 bend at each exit point.

Eh.....I'm not too crazy about 3" unless your 90's are long sweeps (utility-grade). Standard 90's are a bit tight for pulling innerduct. Other than that, 3" will be plenty.

Be careful about the number of bends on the duct as well but, a 3" should do it as long as the bends are sweeping or no more the 3 90 degrees.

100%....pull a flexi-pipe inside the 3" for the fibre for protection. If you do this, ask the customer for a 4" because the pipe will take up much more room than the fibre so, it will leave you will additional room to pull another cable if you need to for re-inforcement, repair, etc.