Goodbye F, Hello T

As the work heads into the final phase for the Hinkley Connection Project, the team have reached another milestone, as they prepare to remove F-route. Don’t know what F-route is? Let me explain.

All 132kV overhead lines (generally the steel tower / pylon lines) across the country have a route designation, generally of one or more letters. F-route is the designation of the line that runs from Avonmouth Docks area near Bristol, down to Bridgwater in Somerset.

The southern part of the line was switched out and started to be dismantled over a year ago, to make way for the new T-pylon lines running from Bridgwater northwards to the new Sandford 400/132kV grid supply point (GSP). Now that Sandford GSP is energised, the northern half of F-route (from Sandford GSP up to Avonmouth Docks area) has been switched out, and the construction teams are getting ready to remove it.

This is clearly good news for some, especially residents on the western side of Nailsea. Last year, the W-route lines and towers, which had previously sailed over a number of gardens, were removed following the installation of underground cables designed to replace the overhead line. With F-route now coming down as well, more residents will benefit from the lines and towers near their houses being dismantled.

The flip side, of course, is that some residents will now have the T-pylons within eyeshot rather than the old steel towers. But it’s a subjective opinion as to which is preferable. Which would you choose?

But whilst many might be celebrating, I may, if you permit this of a partially deranged engineer, shed just a small tear. F-route has been in place since the 1930s, distributing power out of the now closed Portishead power station. It has served the people of Somerset for about 90 years, supporting businesses and residents in the region, and making a significant contribution to the development of this part of the country.

Whilst not pretty (unless you happen to like symmetrical steel towers), it is a testament to the good planning and foresight of the engineers who built the world’s first integrated transmission system, following the creation of the Central Electricity Board in 1926. Whilst the towers have been painted and patched up over the years, they are as they were the day they were built (well, apart from new insulators and conductors…).

The changes that have taken place whilst F-route has been standing are staggering: the second world war, the electrification of the nation, the rise of the dominance of silicon for microchip computing power, the rise of renewable generation, and not to forget the recent trend of young lads wearing white socks with trousers that stop above the ankle (I know, I don’t get it either).

I spent many a happy hour studying power flows along F-route in my early days with WPD as a system planner, trying to work out how much generation could be added without overloading it (which I think we just about achieved!). Maybe I should ask for a piece of the steelwork, for posterity.

So yes, F-route is going, the new T-pylons are coming. It’s a microcosm of change on the electricity system across the country, as network with small capacity is replaced with higher capacity, in order to meet our goals for net zero. There’s a lot more of this change to come, but thank you F-route for your service. It’s been emotional ??.