Pylon of the Month - October 2023

Pylon of the Month - November 2023


November's Pylon of the Month was sent in by a fellow pylon fan with the comment that:
You’re probably not aware that over the course of this year the National Grid has changed the line of pylons between the Offerton substation and West Boldon in Sunderland / South Tyneside. They are now in the process of removing the old 275Kv towers that still stand wireless.
While I keep an ear to the ground, this was the first I'd heard about this development in the North East of England. The email also mentioned that the new 450 kV towers might be related to the opening of a new electric vehicle battery factory. Google didn't turn up anything definitive about this, but Envision is working with Nissan on just such a factory that is due to open in 2025 according to this article on the Electrive website. There is something about pylons without wires that I find rather sad - pylons without a purpose - but I imagine that the old towers will soon be taken down. Perhaps they will be recycled and born again as part of one of the many new lines planned over the next decade. 
About 8-10 new 450Kv towers have been installed and according to the sender of the picture,
One of the towers (not photographed - though I could do one if you like) is of an odd shape that seems to be where the new series joins the old series.
Of course, I took up the offer of a photograph and here it is. I'm hopeful that one of the many fans of the website expert knowledge about the National Grid will be able to shed some light on the details of how the old 275 kV and new 450 kV pylons were brought together.
Finally, October saw my first TV appearance on the BBC's Politics SouthEast programme. In that part of the country, the many proposed new pylons are causing a certain amount of controversy and my job was to try and persuade people that pylons are beautiful. I'm not sure whether I succeeded or not, but I enjoyed the chance to get my message out there!


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A nominal (declared) voltage in a polyphase system is RMS phase-to-phase.

In a single phase system it is RMS phase-to earth.

So, on a national grid transmission line, if you measured the voltage between any two phases you would record 275 kV RMS or 400 kV RMS.

There are no 450 kV lines in the UK. Even if the peak voltage was declared nominal, the peak could not be more than 400 kV, which would mean the RMS would be 0.7x peak.

This is clearly understood in the distribution and transmission industry.

(reference : experience working as an SAP engineer in distribution and transmission)

Pylon of the Month

It is the word nominal and how it is defined that is the key here (and whether we are talking peak voltage or RMS). There was agreement from those in the industry at @pylonofthemonth on Twitter that the regulations will need to be updated soon.


Lots of mention of 450 kV towers.

Is this correct?

It is illegal in the UK to transmit at more than 400 kV

The Electricity Safety, Quality and Continuity Regulations 2002

"No overhead line shall be used for the purpose of supply at a nominal voltage greater than 400,000 volts."

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