After two pylonless months, July's pylon comes all the way from the hills outside Wellington, New Zealand. The picture was taken looking south with the Makara wind farm in the distance and beyond that the South Island, with the Cook Strait in between. Whenever I think about New Zealand, a couple of things spring to mind. The first is a piece of music called Land of the Long White Cloud by Philip Sparke that I played many years ago with Besses o' th' Barn brass band. I don't remember many pieces I played nearly forty years ago so something about it must have been special. You can hear it being played at the 2022 European Brass Band Championship. The second is an exchange between Queen Elizabeth and her equerry, Sir Kevin in Alan Bennett's novella, The Uncommon Reader: 

"New Zealand, that land of sheep and Sunday afternoons….If one wanted to pass the time one would go to New Zealand". 

I think it was meant as a gentle dig at New Zealand, but it's a country that is high up my list of places to visit and as my wife is a big rugby fan and has relatives there, she wouldn't take much persuading as long as we went during the rugby season. 

Anyway, back to the pylon. It was emailed in by a fan of the blog who has been involved in the electricity industry for 30 years so the email was packed full of interesting links. The very first electricity generated in New Zealand was in 1888 and it was from a hydroelectric power plant in Reefton that supplied the inhabitants of the town at a cost of £3 per year for every light in the house. Today, around 90% of New Zealand's electricity is from renewable sources, and in the words of this month's pylon provider "Despite being a long stringy network, over difficult, mountainous, earthquake-prone terrain, and exposed to extremes of weather New Zealand enjoys a highly resilient and reliable transmission system". It also includes an HVDC cable that links the North and South Islands and although HVDC was being used for various projects from about 1954, the construction of the inter-island link from 1961-65 made it fairly cutting edge in technological terms. An interesting historical footnote is that the cables used for the link were made by a company, British Insulated Callender's Cables (BICC), that played a significant role in the construction of the British National Grid.

I'm resolved not to miss any more months this year, so although that's all I've got for now, I'll be back again soon!

June was busy, so busy that it was a pylonless month, but on a walk in the Chilterns at the start of July this pylon caught my eye and it now has the privilege of being July's Pylon of the Month. It's just outside Great Missenden, a lovely town with many literary links. Roald Dahl lived here from 1954 until his death in 1990 and if I'd had more time, I would have visited the Roald Dahl Museum and Story Centre because I have so many happy memories of his wonderful stories, both as a child myself and also as books I read aloud to my own children. My favourite? A toss up between Danny Champion of the World and James and the Giant Peach. Anyway, David Cornwell (John Le Carré) lived there when his first book, Call for the Dead, was published and Robert Louis Stephenson spent a night at the Red Lion pub in 1874. Sadly the pub is now closed (it's now an estate agent) but you can see a few images of it courtesy of the Lost Pubs Project.

Enough local interest and back to the pylon. It caught my eye for two reasons. One was the mobile phone antennae attached to it, the other (as pointed out to me by the friend with whom I was walking) was the different insulator discs on the left and right of the pylon. For more about how mobile phone coverage works you Wikipedia is a treasure trove of information. I was intrigued by the different insulators on each side of the pylon so asked for information on Twitter as @pylonofthemonth.

A quick check on the Open Infrastructure map confirmed that it is the 400 kV line mentioned by @IanBottomer and as a result of asking the question on Twitter I know more about reconductoring transmission lines. As do you, if you've made it this far. If that's left you hungry for more, here's a video showing live line reconductoring. That's all for now - see you in August!

September's Pylon of the Month is a bit of a retro photograph that I took myself on a Holga camera which is a "true cult classic of analogue photography" according to this Lomography website. I'm still experimenting with it as you can see from the fact that the image above includes part of the preceding and following frames and I decided to keep that in the (probably vain) hope that it would look a bit more arty and experimental.

Anyway, the picture is of the Cowley substation near Oxford (and Didcot power station) where the 400 kV lines from Didcot get stepped down to 132 kV.  The marvellous 'High Voltage Substations in the United Kingdom' is your go to source for information if you are looking for something similar in your part of the UK.  The Electrical Engineering Portal tells us that High voltage substations

are points in the power system where power can be pooled from generating sources, distributed and transformed, and delivered to the load points. Substations are interconnected with each other so that the power system becomes a meshed network. This increases the reliability of the power supply system by providing alternate paths for flow of power to take care of any contingency so that power delivery to the loads is maintained and the generators do not face any outage.

I particularly like the busbars that can be seen in the background and they give the picture a futuristic vibe. As you approach the site, the contrast to the green fields sloping down to the nearby River Thames is particularly striking.  The Cowley substation has also been in the news recently because it the site for the largest hybrid battery ever deployed. The 50 MW battery will power a 10 km network of electric vehicle charge points. This energy superhub is needed to support the more widespread use of electric vehicles and the charging points they will need in Oxford. It should be completed by 2022.

October slipped by without a pylon and November was in grave danger of going the same way until two things happened.  One was a comment on the blog asking when the next pylon was going to be posted and the other was a visit to Geneva where I saw this beauty.  But it wasn't just Geneva, this pylon is actually inside the cathedral of physics that is the 'Conseil Européen pour la Recherche Nucléaire' or CERN as it is know all over the world.  As a Physics teacher this is about as good as it gets and so how could I possibly resist.

CERN uses quite a lot of electricity when it is up and running:

At peak consumption, usually from May to mid-December, CERN uses about 200 megawatts of power, which is about a third of the amount of energy used to feed the nearby city of Geneva in Switzerland.

The annual electricity bill is about €60 million but about 90% of this is linked to the operation of the accelerators and at the moment, the Large Hadron Collider, is shut down for maintenance and upgrade work so there whoever has the job of feeding coins into the electricity meter must be having an easy life.

This second long shutdown (LS2) is due to be completed by early summer 2020.  Until about March visiting CERN is definitely worth the effort as you can get underground and look around in a wat that just isn't possible when everything is up and running.  Get there whilst you can!

 This month we have a Scottish pylon from Loch Errochty, a man made freshwater loch in Perth and Kinross.  The pylons are on the Beauly to Denny power line which brings power from renewable sources in the north of Scotland to consumers further south.  It was (and remains) very controversial and the Herald Scotland reported back in 2015 that 'Its impact on the Highland landscape was compared to taking a razor blade to a Rembrandt'.  Those who planned and built it insist that it is essential if Scotland is to meet national renewable energy targets.

You can see a more zoomed out picture below.

The month of May passed by without a pylon and so summer is now here rather than 'icumen in'.  This month's pylon, however, is looking back to a day in the Alps earlier in the year when a fan of the website took time out to take this picture of a mountain pylon.  The angle of the transmission lines leaving the pylon is pretty impressive, but sadly for pylon fans everywhere I couldn't find any technical details of maximum permissible angles or the engineering challenges of building pylons in mountainous areas.

 The email by which the picture arrived was pithy and to the point:

At Plan des Queux near Pointe de Daillant in French Alps. Height: 2150m. 

It also showed evidence that this pylon fan had been willing to go the extra mile (metaphorically if not literally):

Accessed on foot.

I couldn't track down the exact location on a map, but a quick look into electricity in the French Alps led to a story that I found impossible to ignore.  

So if you're a pylon fan and a cheese connoisseur on a skiing holiday next year then surely you won't be able to resist popping to Albertville.  If you do and there pylons on view please do send me a picture!

Happy New Year (somewhat belatedly) to pylon fans everywhere!  

Despite the relatively mild and wet weather as I write this month's post, February seemed the right month for this fantastic picture to feature as Pylon of the Month.  It was taken in West Yorkshire just outside Ripponden by Adrian Jackson.  As he pointed out in the email he sent in with the picture:

The photo has only been treated to change exposure and colour balance, no pylons have been added. There are actually two lines of pylons which both turn through ninety degrees.

Now for some serious pylon geekery.  Talk of turning through ninety degrees above prompts me to talk about the difference between pylons where the transmission line is running in a straight line as opposed to when there is a change in direction.  In a straight line run, the line is suspended from the pylon by vertical insulators (see the second and third pylons going down the hill above).  However, when there is a change of direction (like in the pylon in the foreground above) the insulators are horizontal and the pylon is known as a tension pylon.  More from the National Grid on a page talking about the new T-pylons:

In a perfect world electricity transmission lines would run as straight as possible, but natural barriers, such as hills, rivers and roads, have to be circumvented or crossed and land rights issues can often require a route to turn a corner.  This places a lot of lateral strain on a pylon, to the side where the line turns, and so the suspension design needs to be supplemented so pylons can resist being pulled to one side.............. the extra strength required will mean that the wires will not be able to be suspended vertically from insulators, but will instead need to be held in place more securely by horizontal insulators tied to the pylon itself – hence the term, tension pylon.

You might also notice above that there are loops of wire dangling from the tension pylon that you don't see on pylons where the line is running straight.  These loops are known as 'jumper loops' and again from National Grid:

Due to the lines being tied to the structure itself by insulators, we have to provide a path for the electricity to continue to flow. So, we use ‘jumper loops’, which are short sections of electrical wire connected to the main (live and earth) wires just before they tie to the insulators, terminating the line to the cross arm. The jumper loops are designed to ensure the live wire does not touch the earthed structure.

What a great way to start 2017. A fabulous pylon picture in a Yorkshire landscape and technical pylon talk.  To make February even better, make sure that you get along to the Wellcome institute for their "Electricity: The Spark of Life" exhibition which opens on 23rd February and runs until 25th June.  If you team that up with watching 'Amongst Giants' a film about Yorkshire pylon painters starring Pete Postlethwaite then you'll really have ticked all the boxes.

This has been a very busy month on the pylon front.  As well as making it onto the BBC website (Meet the Pylon Spotters) along with Flash who runs the Pylon Appreciation Society, I have done several interviews on local BBC radio stations about pylons.  The reason for this is that the six new T pylons (which I talked about back in November 2011) have been at installed at the National Grid training centre in Nottinghamshire and for a couple of days the UK went pylon mad, setting a new daily record of 4265 hits on Pylon of the Month.

I could have let all this publicity go to my head, but after considering featuring the new T pylon for April I have decided to stay true to the many fans who have sent in pylon pictures.  When I get a 'real' picture (rather than one from the internet) of the new T pylons I'l definitely use it, but until then it is business as usual.  So this month's picture was taken in Edinburgh and sent in with the following message:

Our colleague............is very keen on your blog ‘Pylon of the month’ we took these photos out of our office windows earlier today – it would make his day/week/month if they could be included in your blog...... 

The window in question seems to be at the Milton Road Campus of Edinburgh College, which rather fittingly offers Electrical Engineering amongst many other courses.  With any luck, the news feed on their home page might soon be announcing the exciting news about Pylon of the Month featuring a nearby pylon.  It might even get people at the college debating whether they prefer the old lattice pylons as featured above or the new T pylons.  Flash Bristow has no doubts that 'These new electricity pylons will make Britain a duller place' although I'm not so sure.  They won't be replacing existing pylons and even new pylon lines will have the option of using the T pylons or not, so with variety being the spice of life perhaps it will enhance the pylon offering in the UK.  For lots on this and for more regular pylon action go to Twitter and @pylonofthemonth.  

Happy New Year to pylon fans everywhere!

This month's pylon(s) comes from South Africa and is yet another another addition to the 'pylon pictures taken out of the window of a moving vehicle' category.  I took it in December whilst on a family holiday in South Africa and the pylons can be found near Stellenbosch, just after you join the N2 to head East on the fabulous Garden Route.   

A bit of research tells me that South Africa currently relies heavily on coal for energy production (88% according to a graphic in the Observer's January Tech Monthly, but 77% according to Wikipedia) largely because there is a lot of coal in the norh of the country.  It also revealed that in June 2014 Johannesburg suffered power disruption due to:

......the theft of 88kV electricity pylons between the Nirvana and Nancefield substations.  City Power electricians are currently in the areas and have started the project to replace the stolen pylons and also to repair those that can be replaced....

I had to follow up this story, but my visions of whole pylons being carted away on the back of a truck were dashed when I read that:

cross members of pylons were stolen, causing the bolts to loosen at the base of a pylon, resulting in the collapse of one of them.  The next pylon on the circuit also collapsed as a result of the strain.

I'll sign off there for now, but with plenty of pictures lined up for 2015, make sure that you come back regularly for more pylon action.

This month's pylon comes from Kennington just outside Oxford and for reasons that will become obvious, I took it myself very recently.  It is very easy to find, being a few hundred metres from Sandford Lock on the Thames on the Sustrans cycle path from Abingdon to Oxford.  But the main reason I chose this pylon is because I could get a close up of something attached to the wires just before cables join the tower. Once you have seen the in the picture below, you will see them everywhere, but unless you are a real pylon spotter you have probably never noticed them before.

The objects in question are the dumbell shaped objects and they are known as Stockbridge dampers or dog bone dampers because of their shape.  They perform a vital role in preventing damage to the cables and in order to explain how they work, it is time for a little bit of theory.  Some readers of the blog might know that I am a Physics teacher, but I will try to stop myself from getting too carried away.  I'll also try to get the physics right without over complicating or over simplyfying things, which might not be as easy as it sounds.

The basic problem is that wind blowing on the cables can make them vibrate, or more specifically vortex shedding on the leeward side leads to this undesirable effect.  It can do this in a number of ways, but one of the modes of oscillation is called Aeolion vibration or flutter.  The vibration has an amplitude of a few millimetres to a few centimetres (this is how far the cable moves up and down) and a frequency of anywhere between 3 - 150 Hertz (vibrations per second).  This kind of effect, where some a driving force (in this case the wind) causes something to vibrate at its natural frequency is very common.  If you have ever seen or heard a washing maching as the drum speeds up in the spin cycle, you might have noticed that there is at least one particular speed where the washing machine shakes violently.  The problems with the Millenium Bridge in London when it wobbled as people walked across it just after opening were also a variation on this theme. But the most dramatic example involving the wind is probably the collapse of the Tacoma Narrows Bridge and if you haven't seen a video of the wind induced oscillations, now would be a good time to tick that off your 'things to do before you die' list.  But back to pylons, because as you will know if you have ever bent a paperclip a few times, repeated stress can lead lead to the metal failing and in the case of pylons on a windy day (or more likely the cumulative effect of many windy days) this could lead to strands of the overhead power lines breaking.

So how do Stockbridge dampers help?  In very simple terms, instead of the wire vibrating the masses on the end of the damper vibrate instead and so the cable vibrations are 'damped' or reduced in amplitude. The idea was invented by George H. Stockbridge in the 1920s and originally consisted of two small blocks of concrete on the end of a piece of metal wire.  

The original US patent is an interesting read if you want to know more, but in the words of the inventor:

My invention relates to means for preventing objectionable vibration in suspended cables, such as are used in electrical transmission lines and the like.....

The wikipedia page on Stockbridge dampers also has more information, but there is much that I would like to find out about how they are used.  In particular, are all dampers the same or do they vary depending upon the specification of the cable?  If you work for National Grid and know the answer please do get in touch and if you had a real life Stockbridge damper that I could use when teaching about resonance in my Physics lessons, I would be extremely grateful.

If this was all a bit too much information for the casual visitor to the website just looking for a new pylon picture then I can only apologise.  I hope that you can at least spot a few Stockbridge dampers on your pylon travels and if nothing else, it might make you realise that there is more to pylons than meets the eye.