Avonmouth

Current construction activity

Date from

Date to

Activity

May 2021

2024

Building and energising new pylons

20202024Removing existing pylons

2018

Ongoing

Roadworks and traffic management

2018OngoingAccess to public footpaths and rights of way

Overview – Summer 2023

National Grid is moving into the final stage for completing the north section of the Hinkley Connection route between Sandford and Seabank substations.  

The new 400,000 volt lattice pylons in and around Avonmouth are now complete.  

Rather than using the T-pylons seen elsewhere on the Hinkley Connection route, we’re using the traditional lattice design. At approximately 50 metres high, they provide the height required across the River Avon and can navigate the tighter turning angles through Avonmouth’s industrial port area to complete and connect the final section of the route into Seabank substation. 

To make way for the new 400,000 volt connection route, we are removing 67 kilometres of existing 132,000 volt lattice pylons and overhead wires stretching the landscape. 248 of the 249 lattice pylons have now been removed.  

In August 2023, we waved goodbye to the two 91-metre pylons that once stood on either side of the bank of the River Avon. In the same month, we removed the line of pylons from Avonmouth village residential area, including the pylon that loomed over Avonmouth C of E Primary School and Daisy’s Nursery.  

Near Seabank substation, our contractor, J Murphy and Sons, are continuing their work to modify  the existing electricity network, replacing nearby pylons at Crooks Marsh with new underground cables.  

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 6 million homes and businesses. 

 

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Take a look at our detailed map

Avonmouth timeline

Completed September 2020

 

Modify Avonmouth substation and existing overhead line to the east of the substation

Work carried out:

  • Replaced a small section of overhead line to the north of the substation with underground cables.

  • Constructed a new cable sealing end (CSE) pylon to connect the underground cables to the overhead line.

  • Changes inside Avonmouth substation to enable the connection of the new underground cables.

  • Reinstatement work including removal of the temporary construction compound and part of the haul road.

To be confirmed

 

Modify Seabank 132,000 volt substation and the existing overhead lines at Seabank

What we're doing:

  • Building a temporary construction compound and temporary entrances and access roads to allow construction traffic to enter the undergrounding site from the local highway.

  • Undergrounding a small section of the three existing overhead lines at Seabank. This will enable the new overhead line to pass safely overhead.

  • Building three pylons to connect the existing overhead lines to underground cables.

  • Modifying Seabank substation to enable the connection of the new underground cables.

  • Removing the existing overhead lines that are no longer needed in this area.

 

Mid 2021 to mid 2024

 

Build new 400,000 volt overhead line

What we're doing:

  • Building temporary entrances and access roads to allow construction traffic to enter site from the local highway.

  • Building a new overhead line from Sandford substation to Seabank substation (approximately 31.2 km).

  • In this area, we'll use a mix of steel lattice pylons and T-pylons.

Mid 2021 to mid 2024

 

Remove the existing 132,000 volt overhead line

What we're doing:

  • Removing the overhead line from the A368 in Sandford to Avonmouth substation, which will make way for, and minimise the visual impact of, the new connection.

  • Removing a small section of the existing overhead line to the east of Avonmouth substation.

To be confirmed

 

Modify Seabank 400,000 volt substation

What we're doing:

  • Extending the existing substation to enable the connection of the new overhead line.

  • Modifying the existing site access road.

  • Removing unnecessary electrical equipment.

  • Installing a perimeter flood defence wall with flood gates around the substation to help guard against tidal flood risk.