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Tickenham to Portishead
Current construction activity
Date from | Date to | Activity |
June 2021 | Late 2024 | |
May 2021 | 2024 | |
January 2020 | September 2021 | |
2018 | 2025 | |
2018 | Ongoing |
Overview – Summer 2022
In May 2021, National Grid started work to build the northern section of the new 400,000 volt overhead connection between Sandford and Seabank substations. We’re using T-pylons for part of the route between Sandford and Portbury, and new traditional lattice pylons through Avonmouth to make the final connection into Seabank substation.
In July 2022, our contractor Balfour Beatty started erecting new lattice pylons in Avonmouth. In early Autumn 2022, work will start to build 68 new T-pylons between Sandford and Portbury.
We expect T-pylon components to be delivered to the working areas, with erection of the new pylons to start from September 2022. All pylons will be constructed with the wires in place by 2023.
By using the innovative T-pylon design, the height of the new 400,00 volt infrastructure is being reduced by a third compared to an equivalent 400,000 volt lattice pylon (35 metres compared to 48 metres). The base of the T-pylons also requires less land meaning that their footprint on the ground is significantly reduced.
In April 2022, our contractors returned to Portbury Wharf Nature Reserve to re-start the work needed to install underground cables that’ll replace existing pylons to the east of their substation, and to build two new T-pylons in the reserve itself. Our main construction activities in the nature reserve are timed to avoid disturbance to wintering birds and other wildlife.
To make way for the new 400,000 volt connection, National Grid is removing 67 kilometres of existing 132,000 volt overhead wires and pylons – 249 in total from the Somerset landscape. We removed a line of 132,000 volt pylons between Nailsea and Portishead in 2021. Work to remove 37 kilometres of pylons between Bridgwater and Sandford is underway. During 2023, we’ll remove the line of existing lattice pylons that runs from Sandford to Avonmouth.
Thank you from everyone working on the project for your patience as we continue our work to deliver electricity safely, efficiently, and reliably, and support the UK’s ambition to achieve net zero by 2050.
Contact our community relations team to register for project updates direct to your inbox.
Tickenham to Portishead timeline
Early 2020 to mid 2021
Underground the 132,000 volt overhead line between Nailsea and Portishead Substation
What we're doing:
Building temporary entrances and access roads to allow construction traffic to enter site from the local highway. You can find more information on our construction information page.
Building temporary construction compounds.
Building a 132,000 volt underground cable between Nailsea and Portishead Substation.
Building a new CSE pylon to connect the existing overhead line at Nailsea to the new underground cables.
This new underground cable section is being built as a direct result of feedback received during our consultation. It will enable us to completely remove the existing 132,000 volt overhead line that currently runs very close to people’s properties.
Mid 2021 to mid 2025
Build new 400,000 volt overhead line
What we're doing:
In this area, to minimise disruption, we will be sharing temporary construction compounds, and temporary entrances and access roads built for other elements of the build.
Building a new 400,000 volt overhead line from Sandford Substation to Seabank Substation (approximately 31.2km).
We will use T-pylons in this area.
Mid 2021 to mid 2025
Remove existing 132,000 volt overhead line
What we're doing:
Removing approximately 9 km of Western Power Distribution’s (WPDs) existing overhead line between Nailsea and Portishead substation that currently runs very close to people’s properties. We are removing this as a direct result of feedback received during our consultation.
Removing WPDs overhead line from the A368 in Sandford to Avonmouth, which will make way for, and minimise the visual impact of the new connection.
Early 2021 to mid 2025
Modify Portishead Substation and the overhead line to the east of the substation
What we're doing:
Making changes to the inside of Portishead Substation to enable the connection of the new 132,000 volt underground cable from Nailsea.
Building a temporary construction compound to the east of the substation.
Building temporary entrances and access roads to allow construction traffic to enter the undergrounding site from the local highway. You can find more information on our construction information page.
Removing a section of 132,000 volt overhead line to the east of the substation and replacing it with underground cable. This will enable the 400,000 volt overhead line to pass safely overhead.
Installing a Cable Sealing End (CSE) pylon to connect the new underground cable to the existing overhead line.
This work will be done on our behalf by WPD.