Posted: July 23rd, 2013 by tomabbott
Comments (8)

T-pylon offered for electricity transmission connection in the UK for the first time

We’re pleased to announce today that the T-pylon, which was selected in an international competition organised by the Department of Energy and Climate Change, Royal Institute of British Architects and National Grid, is being offered for the first time in the UK for a new electricity connection in Somerset.

Nick Winser, National Grid Executive Director said

“The competition was held to find a design which would meet all our safety and reliability criteria and belong to the 21st century. The steel lattice pylon has served us well over the years and will continue to be part of the landscape but we’re looking forward to see people’s reaction to the new T pylon design”.

Secretary of State for Energy and Climate Change, Edward Davey said:

“To see T-pylon becoming a reality just 20 months after winning the competition, is a fantastic achievement for National Grid and the Danish architects, Bystrup, and I’d like to congratulate them on their progress. One of the key objectives of the Pylon Design Competition was to see if innovations in design and technology could improve an 85 year old structure, and one that has divided popular opinion since its inauguration in the 1920s.

“We face a significant challenge over the coming years connecting new electricity plants to our homes and businesses.  Now communities can be offered a new choice and a radical departure from the traditional lattice. A smaller pylon, one third shorter than its predecessor, with different finishes allowing it to blend into the landscape – T pylon is a striking and elegant design.

“I’m looking forward to seeing T-pylon put into service; a graceful, refined structure fit for the needs of our low carbon, 21st century.”

The Hinkley Point connection which runs between Bridgwater and Avonmouth is needed to carry all the new electricity generation planned for the South West.  This includes the new nuclear Hinkley Point power station which, if it goes ahead, will be one of the largest single generators in the country. 

You can read more about the Hinkley Point connection on the project website.

Comments

  1. simon millgate /

    Having Just watched the video,
    what a fantastic approach to the design of a new type of pylon,
    it looks very well designed and thought about and definately 21st century
    well done!!!

    Reply
  2. Michael Milner MIET /

    I presume that maintenace access has to be done by crane or “Cherry Picker”.
    No more climbing up the outside; or can you get up the inside? In remote areas a crane would be difficult to employ.

    Reply
    • Philip Belben /

      The crane is mainly needed to erect the pylon – it comes in a very few large pieces.

      There is an error of fact in the video – steel monopole pylons _have_ been considered before at HV in the UK. I don’t think the 400kV design was ever built, but I went to photograph the 132kV version on the Erdington to Fort Dunlop line when I was working on my own entry to the pylon competition. One thing I noticed was that the towers had climbing bolts starting a bit above head height and going all the way up the tower. So all you need is a ladder to get to the first bolt.

      The bolts show well in this photo on Flickr: http://www.flickr.com/photos/pdb11/12119607645/

      Reply
  3. Alan Boswell /

    I notice that the clearance between wires is much less than in the conventional lines used now. This allows the height of the pylons to be reduced significantly. On the other hand, the spacing from one pylon to the next looks a lot less, presumably to reduce to possibility of contact between the lines in high wind. Is this a fair comment and how many more pylons will be necessary?
    Former member, former Institution of Electrical Engineers.

    Reply
    • Philip Belben /

      The wires are not as close together as they seem! The competition rules specified a minimum spacing of 8 metres; the existing “L12″ design has wires at about 8.9 metres, while the earlier design “L2/2″ (used on the Hinkley to Melksham line) cuts it very fine at 7.7 metres.

      The insulators needed for the T pylon are longer than a those on conventional pylon, because they need to withstand the phase to phase voltage and not just phase to ground. I estimate that you’d need nearly 7 metres anyway. What we saw of them on the video suggests that the conductor spacing is a little more than the insulator length, so 8 metres is about right.

      The T pylon manages to be so compact because the wires are arranged in an equilateral triangle, the smallest possible shape that maintains the minimum spacing.

      I’m not sure about the reduced span – I think that might also be an illusion deriving from the compact appearance. Reduced span would not only allow lower pylons (less sag for the same ground clearance) but also a smaller conductor spacing (conductors anchored more often flap about and clash less). But the eight metre spacing suggests to me that they have not actually reduced the span.

      Reply
  4. Tim Butterfield /

    Hmmn. Very nice I suppose, but they must cost an absolute fortune to build!

    Reply
  5. Dale Milligan /

    The best thing to do is to keep some pylons and build T-pylons, this will satisfy people who like both designs of pylons. Pylons should have their frames gradually replaced with stainless steel which will not rust and doesn’t need to be painted. The base of pylons should be inserted into concrete. Mud gets soft when it rains.

    The T-pylon should be made of stainless steel. The base of the T-pylon should be inserted into concrete. Stainless steel is a good metal because it is strong and does not rust. T-pylons are not as safe as pylons because the cables are lower than the cables on a pylon.

    Reply
    • Philip Belben /

      As one of the “!people who like both designs”, I totally agree – keep some of each!

      Foundation design for pylons is a whole field of study in itself! I’m an electrical engineer, so I have only an outsider’s view, but all pylon foundations that I have ever seen use large concrete structures to anchor the tower. These are often concealed below ground, so that it looks as though the pylon is simply anchored in the soil, but believe me, the concrete is there, and important!

      As for stainless steel, there are a great many stainless steels around, all with slightly different additives. In choosing a steel for the tower, there is a trade-off between structural properties, corrosion properties and cost. In general, the stronger the material, the harder (and more expensive) it is to fabricate parts. Some of the alloys with good corrosion resistance are again (I am told) hard to work in the fabrication shop, and the solution may even today be to use an alloy with lower corrosion resistance and paint it more often.

      Some stainless steels you could in theory get away with not painting at all, but I am not sure that a shiny finish is really best for a pylon. Brand new pylons are zinc galvanised, and look nice shiny, but the metallic grey-green paint used after the first few years blends into tha landscape a lot better. Be glad they don’t paint them with red lead!

      Reply

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