Pylons

Re the Namibia pylon...

There were no safety notices either.

If you can't see that it is bloomin' dangerous you deserve what you get. Rather a nice simple design, I like it.

[high_vacuum_house]

It isn't just pylons that are interesting. If you look through the fences at some of the transformers, you can sometimes work out what is going on. There are lots of old and famous manufacturers names to be seen including Brush, English Electric, GEC ect.

Our site in Wakefield has a 11KV/33KV step up transformer and on the side has a nice vintage Ferranti automatic tap changer. Looking through the observation window there is a very nice looking mechanism made of machined brass inside.

Christopher Capener

[Tractorfan]

Hi,
I've always found electrical supply equipment fascinating, and wished I'd taken more photos when I was in the power industry and occasionally worked inside substation compounds. I love these old French tall substations (photos 1 & 5) with their terracotta tiled roofs which are slowly disappearing to be replaced with small package transformers.
Photo 3 shows a small pylon in Spain which looks a bit of a mess (the tower, not Spain!)
Photo 4 was taken during a wholesale replacement of insulators and cross arms on the 20Kv lines near our village. The local area was fed from four diesel generators while the work was carried out.
Cheers, Pete.

[russell_w_b]

There're a few pics of electrical distribution and power infrastructure on my 'Flickr' page, here:- https://www.***********/photos/russel...57603792374210

[Refugee]

One of the components I have seen many times that to me has no obvious purpose.
I would like to see if anyone knows what they are fitted for.
To me they are just clipped onto the cables in pairs close to the insulators at each end of the cable run.
Lightning gaps are obvious to me but these are not obvious.

[Synchrodyne]

They are vibration dampers - see the attachment.

Cheers,

[Synchrodyne]

Originally Posted by Radio Wrangler

Three phases under *double* static lines.

In fact the use of two ground wires appears to be standard practice for high voltages where the three phase wires are horizontally arrayed, as in the case of what might be called the classic steel lattice transmission tower form.

Cheers,

[russell_w_b]

Originally Posted by Refugee

Lightning gaps are obvious to me but these are not obvious.

Stockbridge dampers. They're used to dampen aeolian vibrations set up by the wind. Used on HF curtain arrays too.

[Radio Wrangler]

Some structures exhibit wind-powered vibrations, and the forces can be a bit much for the structure. The classic example is the Tacoma Narrows bridge 'Galloping Gertie' - it's worth finding the film of it if you've never seen it. Also the original Severn bridge turned out to have aerodynamic problems that forced modifications.

Simpler shapes like cylindrical cables are vulnerable to these effects too. You just need the right airflow to make the oscillation tune across a structural resonance and...

David

[ms660]

We had a fire in the garden caused by oscillating power cables

I was in the house....crack crack crack, rushed outside, it only took a me a few seconds, the grass (long) was on fire in six places, the oscillation was slapping together the two uninsulated overhead 230 volt incomer cables, we live in a timber clad house, there had been a long dry spell of weather...Anyways I put the fires out and the oscillation eventually stopped...

Western Power were called out, the oscillations started again, not only on our 230 volt feed but on the 11Kv line that passes over the property boundary to the transformer pole, it turned out to be a horse rubbing it's bum on the utility pole cable stay that the transformer was on.

Just an average day

Lawrence.

[emeritus]

That reminds me of a news item that I read some years ago in, I think, the IEE news, about a stretch of power line on the south coast of England that suffered periodic trips in the autumn for no obvious reason. The cause was eventually traced to flocks of migrating birds, which assembled en mass on the lines to prepare for crossing the channel and then all took off at once. The reaction force of the instantaneous departure so many birds was enough to set the lines swinging and cause a flash-over.

[turretslug]

Originally Posted by Refugee

One of the components I have seen many times that to me has no obvious purpose.
I would like to see if anyone knows what they are fitted for.

Resonance dampers. Look for them on suspension bridge cables and other places where unwanted resonances are likely- the Humber bridge is strewn with them, although care was taken at design.They're one of those things that, once you're aware of them, they seem to be all over the place

[GMB]

As a land owner I can tell you that in vaguely recent times a retrospective legal operation is going on to lease the right to the optic fibre that must have been there for ages. I don't know why, but am guessing that maybe this is to do with using it for purposes nothing to do with the electric companies. I am arguing with them about this as the quite generous deal comes with a lot of nasty restrictions, way more onerous than the de-facto safety issues with the pylon itself.

By the way, you may not realise that pylons host rainbow generators.
Don't believe me? Well here is a photo! You can see the rainbow projector, cleverly disguised as a microwave link, glowing away
Also, the answer to the question about what is at the end of a rainbow is clearly shown here - another pylon, obviously.

[Mr Moose]

Hello,
Strong wind can produce what are known as "galloping conductors".
http://www.tdee.ulg.ac.be/player.php...2loops512k.flv
http://www.tdee.ulg.ac.be/player.php...pndown512k.flv
Yours, Richard

[hannahs radios]

There is a 3 phase HV line out near Bournemouth with horizontal wires rather than vertical it has 2 earth wires above it which seems to point to the use of twin earth wires for these being common practice. Russell loved your photo collection very interesting.

[Peter.N.]

I was leaving a cottage in the aforementioned Fishpond on day when I heard a loud bang behind me and turned just in time to see the body of a large crow falling from an 11kv pole to the ground, it had somehow connected itself across the 11kv supply.

Peter

[ms660]

When they replaced the 11kv poles and line not that long ago on our stretch they put taller ones in, they used a Philipino crew, boy do those guys work.

Our ash tree is about 3 ft short of the line, they are due out soon to pollard it, one of the 11Kv poles is on our land but when I last checked the wayleave payment was meager, I couldn't be bothered at the time.

Lawrence.

[G6Tanuki]

Originally Posted by Refugee

One of the components I have seen many times that to me has no obvious purpose.
I would like to see if anyone knows what they are fitted for.

They're vibration dampers, as others have noted.

On my 11/33Kv 3-phase infrastructure the same function is provided by a short overwind spiral of wire [same thickness as the transmission-line] fitted either side of the insulators. I guess they form offcuts of the main transmission-line . . .

[russell_w_b]

Originally Posted by G6Tanuki

On my 11/33Kv 3-phase infrastructure the same function is provided by a short overwind spiral of wire

Are you sure that's not a cable repair? The procedure is to wrap overound spirals of wire onto the conductors to strengthen chafing and damage, using a thing called a 'Parrot's Beak'.

[Radio Wrangler]

The process of wrapping a wire back around itself, I think, is called 'serving' for thread, it's called 'whipping'

Amazing the junk that lurks in the back of the head.

David