Feeding Long wires through Conduit

[Steve Firth]

Back when my dad was in the Leccy business, they used a ferret to take a string into places that the human arm could not reach.

[Lobster]

In all honesty, a ferret or similar is actually an extremely sensible suggestion. I've done it myself once, years ago using a friend's pet rat we were baby-sitting(?) while she was on holiday, which happened to coincide with some re-wiring I happened to be doing at the time... worked like a charm. If there's anyway you can find somone who has a pet one to borrow, that's definitely the way to go.

Also see:

would have been a hell of a lot easier to have done before you'd buried it - eg using a magnet tied to some string inside the duct, with another one outside - but I'm guessing you've already realised that!

David

[Owain]

The ferret seems to win on popularity.

I assume it's a fairly straight conduit - it would have to be if you're dragging in 40m of cable. Would it be straight enough to get a rocket (firework) through?

Owain

[Owain]

Wouldn't need to be radio-controlled, - a small battery-powered motorised toy car could crawl through. It only has to go forwards until it pops out the other end. If it gets stuck just pull it back.

I used to have a skein of (I think ex-military) very thin but strong twisted-twin flex with teflon insulation; 40m of something like that would weigh next to nothing so the motorised buggy wouldn't even need to be battery powered - the draw wire could double as power feed.

Owain

[Guy King]

The message from " [e-mail]" contains these words:

Not really. Provided the pipe doesn't leak then it'll spend a few minutes lowering the pressure in the pipe, then if you've attached the line to something like a polystyrene ball it'll not know how long the pipe is.

Failing that, Lego or Meccano motors will run for long enough easily. Shouldn't be too hard to knock up a runner.

[robgraham]

metres worth' bit.

I think I would try the vacuum cleaner idea but the sie of the pipe rather is against that - if it is straight I would try a pig made out of a length of dowel - say 200-300 mm - with 50mm thick polstyrene discs which have reasonable clearance from the wall holding in place washers of membrane grade polythene which act like piston rings and eliminate the air past the pig thus sucking it along with the fairly small vacuum, but large air flow from the cleaner - obviously the largest one you can lay your hands on.

The other option would be to wash the 'string' down with oodles of water but as the water is beyond the bottom end of the pipe still, we a have a 'there's a hole in my bucket .... ' scenario where that idea is concerned !

This is an interesting and somewhat unusual challenge - tell us what the solution is please when you find one !

Rob

[The3rd Earl Of Derby]

Any good with a bow&arrow? ;-)

[The3rd Earl Of Derby]

Then catch a mouse and block the starting end a bit so the mouse cant escape. :-)

[Guy King]

The message from Owain contains these words:

Monofilament fishing line would do fine for the first pull.

[Guy King]

The message from "robgraham" contains these words:

I can just imagine making a manifold and getting all the locals round to plug all their vacuum cleaners in together.

[David Neale]

And all you'll then need is some chocolate sauce or peanut butter (apparently better than cheese...)

[richard]

I don't know why so many raised eyebrows at drain rods, to do 40m is only 40 rods, easily do-able, like another poster has said, borrow the extra ones you need. Rich

[Steve Walker]

No, it would work. Use a cotton-wool ball or similar, attached to strong button-thread, and it'll whistle through with a reasonably powerful cylinder vac (remove bag & filter for that chav-tuning effect!).

Then use button-thread to pull fishing line back the other way, and finally use fishing line to pull your cables.

[gort]

I used to use KitKat with great success to catch them..

Dave

[Stephen Dawson]

The way we used to do it was to use a compressor ( road breaker type ) to blow air down the duct and feed 8mm polyprop rope in till it came out the other, very easy and very quick.

[Guy King]

The message from gort contains these words:

I had a cat called KitKat once!

[Doctor Drivel]

If the conduit is not installed, run the cables through as you install the lengths of the conduit. Simple.

[The3rd Earl Of Derby]

Doctor Drivel wrote: Simple.

That you are.

[Owain]

Read and understand the words "the Large size conduit (circa 5 inch) is already buried in the ground".

Anyway, running cables as you install conduit is contrary to the IEE regs. Conduit has to be complete before any cables are installed. I know this is for France, but that's no excuse for bad habits.

Send up a ferret, a good English ferret, raised on black pudding and beer.

Owain

[Jim Alexander]

There is a clue in "the Large size conduit (circa 5 inch) is already buried in the ground,"

Jim A