Author Topic: Wire Connection  (Read 8646 times)

roo

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Wire Connection
« on: April 23, 2009, 04:49:08 PM »
Suppose you have a long, straight wire under tension, and you do not have access to the ends, and you may not cut the wire.  How would you connect a separate short wire of equal diameter to pull in line (parallel) to the first wire?  The second (short) wire is not yet under tension, and you'd have access to the ends of it.
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Sweeney

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Re: Wire Connection
« Reply #1 on: April 23, 2009, 05:55:23 PM »
This depends on a number of factors eg what type of wire is under tension? (If this were galvanised fence wire then this might be easier than plastic coated wire). Is the tension such that a twist in the tensioned wire is not possible (creating a bight)? A first thought would be to apply some rubber amalgamating tape (or duct tape) to the wire under tension then use a bolt and 2 washers attached to the tensioned wire fastened tightly over the tape (the tape not only gives friction but also helps prevent damage) - attach the second wire to the bolt by wrapping around both ends of the bolt to avoid stressing the tensioned wire by kinking it. Depending on how much stress is applied to the short wire this might suffice. I've attached a drawing of sorts. No knots unfortunately.

Barry
« Last Edit: April 23, 2009, 05:55:58 PM by Sweeney »

roo

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Re: Wire Connection
« Reply #2 on: April 23, 2009, 06:05:16 PM »
This depends on a number of factors eg what type of wire is under tension? (If this were galvanised fence wire then this might be easier than plastic coated wire). Is the tension such that a twist in the tensioned wire is not possible (creating a bight)? A first thought would be to apply some rubber amalgamating tape (or duct tape) to the wire under tension then use a bolt and 2 washers attached to the tensioned wire fastened tightly over the tape (the tape not only gives friction but also helps prevent damage) - attach the second wire to the bolt by wrapping around both ends of the bolt to avoid stressing the tensioned wire by kinking it. Depending on how much stress is applied to the short wire this might suffice. I've attached a drawing of sorts. No knots unfortunately.

Barry

I'm fine with no formal knots being used.  I like the idea of using a fastener to create a wrapping point for the short wire.

P.S.  Perhaps the shorter wire could also be trapped between the washers, on the other side of the fastener, to keep the washers parallel.
« Last Edit: April 23, 2009, 06:13:53 PM by roo »
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Sweeney

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Re: Wire Connection
« Reply #3 on: April 23, 2009, 06:17:06 PM »

P.S.  Perhaps the shorter wire could also be trapped between the washers, on the other side of the fastener, to keep the washers parallel.

Good idea!

Barry

roo

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Re: Wire Connection
« Reply #4 on: April 23, 2009, 06:22:44 PM »

P.S.  Perhaps the shorter wire could also be trapped between the washers, on the other side of the fastener, to keep the washers parallel.

Good idea!

Barry

Thinking aloud, it might be good to have a conical-shaped fastener head to allow the washer to pivot or tilt as required to make up for slight differences in wire diameter.  Hmmm.  But that'd require a slotted hole in the washer... nevermind.

Maybe I should browse the hardware stores and see what kind of wire clamps they have available. 
« Last Edit: April 23, 2009, 06:35:49 PM by roo »
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Sweeney

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Re: Wire Connection
« Reply #5 on: April 23, 2009, 09:33:40 PM »
Roo

There are some specialist fastenings available for fencing wire - I have a couple which join 2 wires using a device which has 2 spring loaded "pistons" inside, each has a slanted face to grip the wire and each piston is held in place with a small spring. Difficult to describe but the wires enter the block at opposite ends and the device acts like a ratchet to allow tension in the wire (I once borrowed a tensioning tool to use with these things) but unfortunately you need access to both ends of your wire. The picture attached may be of some use - it looks very like the devices I used but this may be attachable to a tensioned wire(??).

Barry

« Last Edit: April 23, 2009, 09:35:23 PM by Sweeney »

roo

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Re: Wire Connection
« Reply #6 on: April 23, 2009, 09:47:57 PM »
Roo

There are some specialist fastenings available for fencing wire - I have a couple which join 2 wires using a device which has 2 spring loaded "pistons" inside, each has a slanted face to grip the wire and each piston is held in place with a small spring. Difficult to describe but the wires enter the block at opposite ends and the device acts like a ratchet to allow tension in the wire (I once borrowed a tensioning tool to use with these things) but unfortunately you need access to both ends of your wire. The picture attached may be of some use - it looks very like the devices I used but this may be attachable to a tensioned wire(??).

Barry



Right now, I'm starting to lean toward split bolts, if I can find the right size.  The various wraps I've tried leave me less than confident.  If anyone wants to put in their 2 cents, don't hesitate.
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[Inkanyezi] gone

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Re: Wire Connection
« Reply #7 on: April 24, 2009, 04:45:12 PM »
At the rigging loft where I worked in the nineties, we had a tensioner that clamped onto the wire and provided a holding point anywhere along the wire. The harder the pull, the harder the clamping. It was not the same as in this link, but had a somewhat similar function. I have not found the actual one on the web; it adapted well to many different diameters of wire.

http://www2.northerntool.com/hand-tools/vises-clamps/item-14396.htm

If I were to design something I would prefer something like the Lewmar rope clutch which is like a series of dominoes with holes in them. When tilted they hold, when upright they release; they tilt by the force applied.

http://sv.lewmar.com/products/index.aspx?lang=1&page_id=21
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squarerigger

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Re: Wire Connection
« Reply #8 on: April 24, 2009, 10:26:38 PM »
Roo,

A twin-base wire rope clip should do the trick:

http://www.usbr.gov/ssle/safety/RSHS/AppD.pdf


They can be attached to a wire already under tension and will accept the same size wire rope as is currently in use.  They will not, as far as I know, accept a smaller or larger size wire rope than that which is under tension.  What is the application?

SR

roo

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Re: Wire Connection
« Reply #9 on: April 24, 2009, 11:10:39 PM »
Roo,

A twin-base wire rope clip should do the trick:

http://www.usbr.gov/ssle/safety/RSHS/AppD.pdf


They can be attached to a wire already under tension and will accept the same size wire rope as is currently in use.  They will not, as far as I know, accept a smaller or larger size wire rope than that which is under tension.  What is the application?

SR


I saw some u-bolt type wire rope clips at the hardware store in the right size.  They had slipped my mind for some reason.  I guess my mind wasn't in wire rope mode.  The u-bolt side can be a little hard on the wire, which is probably why they make other types with a double saddle. 

Anyway, I was just diverting some fence wire tension to other wire.  I was curious if anyone had a wire-only solution, but I am happy using specialized hardware to get things done, especially as it seems it might be the only reliable way.
« Last Edit: April 24, 2009, 11:14:01 PM by roo »
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squarerigger

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Re: Wire Connection
« Reply #10 on: April 24, 2009, 11:34:28 PM »
Roo,

The people who work with wire rope at the electric company in re-supporting the cables have a great idea which seems to comprise one section of the pre-kinked wire rope strand from a regular piece of cable.  Taking one of the six pre-kinked strands, they wrap it around the two wires to make a sort of "field-splice" connection - really just a wrap.  They hold for a short (undetermined time) period and may provide the kind of temporary, non-slipping wrap you need.  The space between the "kinks" would be the size of your two strands or a little less, and you would presumably have to experiment a little to see how many wraps of the pre-kinked strand you need.  Big advantage is low-cost and easy application with no kinking of the attached wire or base wire.  Big disadvantage as I see it is not knowing how much load it will take before slipping - maybe use some friction tape over the wire to start with?  Also, if I remember correctly, wire fence rope is single strand - that could present a problem for the pre-kinked wire solution.

This could be the wire-only solution you may be seeking.  You are absolutely correct that the U-bolts would be hard on the wire, either the joined-on or the joined-to piece - not pretty!  The double-base clips are rather chunky.....

SR

SS369

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Re: Wire Connection
« Reply #11 on: April 24, 2009, 11:43:07 PM »
http://handbooks.btcv.org.uk/handbooks/content/section/3290

The above address is to a site that deals with wire fencing, such as barbed wire. These people do that kind of stuff regularly.
Hope this helps.

Scott


Sweeney

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Re: Wire Connection
« Reply #12 on: April 25, 2009, 07:32:23 AM »
This is a very useful site to know about (not least because I now know I was trying to describe a "gripple" in an earlier post) as I have some fencing to repair this summer.

Barry

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Re: Wire Connection
« Reply #13 on: April 25, 2009, 02:56:19 PM »
In the RN we used a loop called a GUY GRIP DEAD END to secure our aerial (antenna) wires - like these....

http://www.newtechindustries.com/newtech/outside_cable_plant/guy_grip_dead_ends.htm

Simple to make too

Gordon