Tickenham to Portishead
Current construction activity
| Date from | Date to | Activity |
| May 2021 | 2024 | Building and energising new T-pylons |
| 2020 | 2024 | Removing existing pylons |
| 2018 | Ongoing | Roadworks and traffic management |
| 2018 | Ongoing | Access to public footpaths and rights of way |
Overview – Spring 2024
National Grid is moving into the final stage for completing the north section of the Hinkley Connection route between Sandford and Seabank substations.
68 new T-pylon structures have now been completed between Sandford and Portbury with the final wires being hung in March 2024. The final diamond shaped insulators were lifted into place on a pylon between Yatton and Kenn in July 2023.
Teams will now work to test and commission the new line, including the new lattice pylons across the River Avon into Avonmouth, in preparation for energisation later this year.
Using the T-pylon design, reduces the height of the new infrastructure by a third. At 35 metres high they are shorter than National Grid's traditional lattice transmission pylons and take up far less room on the land.
To make way for the new 400,000 volt connection, National Grid is removing 249 existing 132,000 volt lattice pylons, and overhead wires stretching 67 kilometres from the Somerset landscape. We’ve taken down 248 of 249 lattice pylons, the one remaining lower voltage pylon, in Portbury, will be removed early in the coming months.
We have begun reinstatement across the new connection route, removing construction access, temporary roads and work pads. You may expect to see more construction traffic on local roads and we will be in touch ahead of any traffic management impacts.
Thank you from everyone working on the project for your patience and understanding as we work to towards full completion of this project which will play such a key role in helping the UK meet its net zero ambitions by transmitting cleaner, homegrown, energy around the UK – enough to power six million homes and businesses.
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Tickenham to Portishead timeline
Completed mid 2021
Undergrounding the 132,000 volt overhead line between Nailsea and Portishead Substation
This work has been completed.
Work carried out:
Built 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.
Built temporary construction compounds.
Built a 132,000 volt underground cable between Nailsea and Portishead Substation.
Built a new CSE pylon to connect the existing overhead line at Nailsea to the new underground cables.
This new underground cable section has been 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 2024
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 2024
Remove existing 132,000 volt overhead line
What we're doing:
Removing approximately 9 km of 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 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 2024
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.