Cable insertion in duct

[apprentice87]

Hi All,

I have to install a cable in a duct! The best way to describe it is as follows; If you can imagine that the duct comprises a vertical section about 3 foot high sticking up out of a concrete floor complete with a 90 degree bend at the bottom of about 500mm radius. The duct then runs horizontally for about 60 meters/65 yards in a straight line and then there is another 90 degree bend and another 3 foot piece sticking vertically up out of the floor.

The entire duct is 4" "ridgiduct" with a nice smooth bore!!

Obviously there is a draw rope in there!

The cable meanwhile, is 5 core 25mm SWA.

With one person pushing and feeding it in, and another pulling the draw rope, is all this likely to be easy enough, or is this not going to be very nice???

The only other cable i have ever stuck in a duct was 25 meters of 35mm concentric service cable [again 4" ridgiduct] and this just flew in, took all of about 30 seconds.

Will this "new" bit be the same, or have i got a shock coming!!!

Thanks all

 

[Andy™]

may be worth pulling a second line through incase the first snaps. or use a much bigger rope

 

[NozSpark]

I'd imagine that it's the bends that are going to cause you a problem,, once past them you should be ok..

Like Andy says,, just make sure that you have a good draw line in and maybe pull a spare in first

Just remember to attach another line to the draw so that you can pull it back so that it's still available for future use

 

[apprentice87]

Hi Andy and Nozspark,

Happily for me, the bends are right at the extreme ends where the duct goes from being horizontal underground to vertical at the ends!! Soooo, i was hoping that it would be possible to more or less push it most of the way around the first bend, drain rod style, and then just push and pull at the same time from the other end!! I am going to use the 10mm rope, so there is no way in this world that will snap!!

I will pull in a second rope though as you say though, so i can pull the first one back if it comes off the cable, and then i will leave the rope in there in case it is needed for use in the future.

Surely to god though, with one person feeding the thing, and maybe two pulling it should not be too bad??? [hopefully he says!!]

It is all outside, so there is loads of room to uncoil the cable and straighten it first.

Glad the bends are right at the ends though, if they were say, half way, i would have thought it would be completely impossible!!

What you think??

john..

 

[Manator]

I sometimes use a lubricant like that yellow stuff, which name abandons me just now, like the others have said I always leave a second draw cord in there as well, future proofing the duct.

 

[Andy™]

I am going to use the 10mm rope, so there is no way in this world that will snap!!

10mm should be fine for that.

i wouldnt bother getting cable off coil, just feed it straight in

 

[kerching]

Ideal Industries Lube Part Number [on the Barrymore/Glitter codification] 77

or Ideal Industries Aqua Lube [ I use it for Fiber Optics, just as slippy ]

At a push washing up liquid helps but is frowned upon so you didn't hear it from me... :coat

just though...if the duct is as dry as a nuns chuff then Talc will work.....if the duct is as wet as an Otter's Pocket then there will be unpleasantness

 

[apprentice87]

Hi All,

I have got a large pot of the lube they use on the rubber seals on the ends of ducts/pipes etc. I have seen it make some sorts of rubber go a bit funny though, so i think i will send off for the proper stuff, better safe than sorry....

There is a very old oil and grease merchants not far from me. Some years ago i went in there, and amongst other things, they had 5 gallon drums marked "petroleum jelly"

I said to the bloke serving; "Is that vaseline??" he said yes. I asked "Why the xxxx would anyone want 5 gallons of vaseline??"

He said "I understand they use a lot on board ship!!!!"

I still have not figured out what they use it for though!!

john..

 

[m4tty]

Is it the navy use it alot? Bums against the wall and all that lol

 

[philbas]

This thread shoud have an X rating

first apprentice87 wants to insert a cable into a duct, then Manator wants to use lubricant

Its all disgusting I tell you

 

[batty]

5 core 25mm times 65 meters that is going to be hard work i have done a lot smaller and struggled good luck.

 

[st3v3]

Silicon spray mate, it will fly through

 

[Evans Electric]

A 5 core X 25 mm sounds interesting , whats that for ?

And as said , as long as someone feeds it should be OK .

 

[steptoe]

as manator says,

'yellow 77'

a 90 bend at each end is gonna be tight over that distance with 5x25mm, shoulda went for double 45s methinks, or those drop bends with the big radius,

I wouldnt worry about the rope breaking(if its decent rope?!), more an issue of it seperating from the cable, its gonna be a sweaty pull, :|

 

[Zeespark]

What about slowly feeding in the SWA from one end, and use a vehicle at VERY low speed to pull the cable through?

AndyGuinness

 

[Andy™]

What about slowly feeding in the SWA from one end, and use a vehicle at VERY low speed to pull the cable through?AndyGuinness

would need some rollers where rope leaves duct or it will probably snap the rope very quickly

 

[Badger]

i did that with the old van and the ducting at the pub, worked a treat mind it was only 4mm armoured 3core

 

[Evans Electric]

Someone feeding the cable should negate the first bend , plus lubricant.

And theres a vast difference between another sparks feeding or any old idiot who doesn't push when you pull!!!

What did you say the 5 core was for !!!

 

[batty]

He didn't its a secret.

 

[Evans Electric]

Ah that explains it then !!