blueshift
Full Member
I dream of wires
Posts: 160
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Post by blueshift on Nov 9, 2008 14:25:29 GMT -5
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blueshift
Full Member
I dream of wires
Posts: 160
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Post by blueshift on Nov 9, 2008 14:27:52 GMT -5
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Post by rillington on Nov 9, 2008 14:50:43 GMT -5
Fantastic pictures and the picture of the three lines at Aber is amazing. You can see why I have such a fondness for north Wales!
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blueshift
Full Member
I dream of wires
Posts: 160
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Post by blueshift on Nov 9, 2008 14:57:10 GMT -5
We have had a 2 week annual holiday in Trearddur Bay, Angelsey for the last 15 years, - I too love North Wales
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Post by Flash Bristow on Nov 9, 2008 18:53:41 GMT -5
Great photos Blueshift! Love the spacer... wierd!
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Post by poyks on Nov 10, 2008 17:12:20 GMT -5
Cool photos! Those spacers look as though they are designed to 'bounce' off the other cable rather than the usual fixed type. Could that be to do with the steep angle and the wind/resonance properties associated with it?
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Post by Dr Fortran on Nov 11, 2008 5:20:56 GMT -5
The peculiar spacers are called hoop spacers.
Using offset conductor bundles without spacers gives better resistance to conductor galloping than traditional twin bundles either with rigid spacers or with flexible spacer/dampers. Not having spacers means that the torsional stiffness of the bundle no longer has an effect. It's necessary to offset the conductors vertically so that they don't rub against each other and that also brings the aerodynamic benefit of one conductor no longer being in the wake of the disturbed air flowing off its partner. Ice build-up is also more even and less likely to cause aerodynamic problems. You can see unspacered twin bundles in my set of photos of L66 towers.
With high power flows, the magnetic field around the individual conductors tends to draw them together so that they contact, a phenomenon known as 'bundle collapse'. The hoop spacers are used to prevent this happening. I've never actually seen them for real myself, so blueshift's photos are fascinating. It looks as though the spacer consists of a helical arrangement around one conductor (not unlike a bird diverter) and a sleeve on the other where it would rub.
Hope that helps.
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Post by poyks on Nov 11, 2008 7:55:02 GMT -5
Certainly does. Thanks for the information.
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Post by jpskertchly on Oct 13, 2009 11:55:47 GMT -5
Great pictures . Ive only just got up and running on the site as you probably know and now I cant drag myself away from it . All these pylon pics are fantastic. I can see Im not going to get anything else done for at least the next week or so ! Thanks again for some great pics. The little "DANGER ELECTRIC FENCE " sign in the second picture does seem rather pointless and strangely inadequate somehow!
JPS.
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