UK National Grid prepares for first T-pylon at Hinkley Point C

05 August 2020

The first T-pylon on National Grid's Hinkley Connection is scheduled to be constructed at the end of July 2021. It will be one of 116 T-pylons along the 57km route, which will connect low-carbon energy from EDF Energy's Hinkley Point C nuclear power plant to six million UK homes and businesses. It will also allow for more capacity on the network for renewable energy from the South West peninsular.

T-pylons have a smaller footprint and use less land (Image: Nation Grid)

Once energised, these will be the UK’s first operational T-pylons and the first new design for a UK electricity pylon for almost a century. Each one has a single pole and T-shaped cross arms which hold the wires in a diamond ‘earring’ shape. It is around 35 metres high; about a third shorter than traditional 400kV steel lattice pylons. It also has a smaller footprint and will use less land.

The Hinkley Connection - which will run from Hinkley to Seabank, near Avonmouth - will be made up of 48.5 km of overhead line and 8.5 km of underground cable through the Mendip Hills area of outstanding natural beauty, which will leave the area free of pylons for the first time since the 1960s.

The full route is made up of 14 interconnected project stages which are set for completion by 2025. Construction work started in 2018 and, as a critical infrastructure project, has continued throughout 2020, National Grid said.

In that time, highlights include, it said:

  • Start of works to underground 132kV lines and remove pylons that run close to and over homes in Nailsea;
  • Completion of the temporary haul road for construction of the Mendip underground cables, including installation of a 90-tonne Callendar Hamilton Bridge - the first to be built in the UK for several decades;
  • The start of trenching and ducting in preparation for the underground cables through the Mendip Hills;
  • Construction of 2400m of bat flyways to maintain habitat connectivity for bat roosts;
  • Start of construction work on two new substations at Shurton and Sandford;
  • Removal of pylons and wires near the M49 at Avonmouth and undergrounding of a short section of cable running north from Avonmouth substation;
  • Installation of a tilting weir on moors near Tickenham to adjust water levels to encourage wading birds to nest and breed

James Goode, project director for National Grid said: "We have already reached some significant milestones on the Hinkley Connection Project, which is a testament to the skills and expertise of the project team and partners. It’s exciting to look forward to this time next year, when Hinkley Connection will see construction of the first new pylon design in nearly 100 years."

Hinkley Point C will be the first new nuclear power station to be built in the UK in over 20 years and will provide about 7% of the country's electricity. The first of its two EPR reactors is scheduled to start up at the end of 2025.

Researched and written by World Nuclear News