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In Spring 2020 we embarked upon a seven-year, £1 billion project, to rewire South London via deep underground tunnels. This vital work will help keep Londoners connected to safe and reliable electricity supplies.
In total, 32.5km of 3m diameter tunnels are being constructed deep below the road network between Wimbledon and Crayford, which will carry high voltage electricity cables.
Most of the electricity supply in South London is currently transmitted through underground cables, traditionally found just below the road surface. Work to maintain them is carried out at street level and can be disruptive.
By housing new electricity cables in deep underground tunnels, there will be a number of benefits:
Tunnel construction is well underway, with the project due to be complete and fully operational in 2027. It follows the successful completion of phase 1 in 2018, which was a seven-year, £1 billion programme, building 32km of tunnels and two new substations in North London.
Time period | Site activity |
Wimbledon | |
May 2022 | Works began on site |
Summer 2022 | Works to the existing headhouse building were carried out, including the removal of the roof |
July 2022 | TBM breakthrough from Kings Avenue site |
Early 2023 | Tunnel repair works, cable bracket installation and final fittings to the tunnel |
Autumn 2023 | Tunnel boring completed along entire route of project |
Late 2023 | Headhouse construction completed |
January 2024 – September 2025 | Site will be occupied |
2026 | Project expected to be fully operational |
Kings Avenue | |
Spring 2020 | Works began on site |
May 2021 – July 2022 | The tunnel was built |
August 2022 – October 2022 | The initial tunnel clean to Wimbledon took place |
April 2023 | TBM breakthrough from New Cross site |
Autumn 2023 | Tunnel boring completed along entire route of project |
January 2024 | Headhouse construction began |
2026 | Project expected to be fully operational |
Bengeworth Road | |
December 2020 – January 2021 | Three public engagement events held with local residents |
August 2021 – May 2022 | Shaft construction works |
February 2022 | Engagement with local residents on substation and headhouse design |
Summer 2022 | TBM breakthrough from New Cross site |
Autumn 2023 | Tunnel boring completed along entire route of project |
Winter 2022 – 2025 | Substation and headhouse construction |
2026 | Project expected to be fully operational |
New Cross | |
June 2019 | Site preparation including ground remediation works to remove unwanted materials and contaminated land began |
January 2022 – September 2023 | Tunnel construction to Kidbrooke took place |
Autumn 2023 | Tunnel boring completed along entire route of project |
March 2024 | Construction on two headhouses began |
2026 | Project expected to be fully operational |
Kidbrooke | |
Spring 2022 | Works began on site |
Summer 2022 | Shaft construction works began |
Autumn 2023 | Tunnel boring completed along entire route of project |
January 2024 | Works began to install cable brackets inside the tunnels from Eltham to Kidbrooke, then Kidbrook to New Cross |
March 2024 | Headhouse construction began |
2026 | Project expected to be fully operational |
Eltham | |
October 2021 – May 2022 | Shaft construction works |
June 2022 | TBM breakthrough from Hurst site |
Mid-2023 | Cable installation in the Eltham to Hurst tunnel concluded |
September 2023 | TBM breakthrough from New Cross site |
Autumn 2023 | Tunnel boring completed along entire route of project |
March 2025 | Headhouse expected to have been built |
2026 | Project expected to be fully operational |
Hurst | |
February 2021 | Work began on site |
January 2022 | Completed 2km of tunnel boring |
February 2023 | TBM passed from Hurst to Crayford |
March 2023 | Headhouse construction works began |
Autumn 2023 | Tunnel boring completed along entire route of project |
2026 | Project expected to be fully operational |
Crayford | |
July 2021 | Digging of the shaft began |
February 2023 | TBM breakthrough from Hurst site |
Autumn 2023 | Tunnel boring completed along entire route of project |
Late 2023 | Headhouse construction began |
2026 | Project expected to be fully operational |
Intermediate shafts and headhouses are required at key points along the route of the tunnel. The tunnel boring machines will link these points as it progresses along the routes.
The shafts and headhouses are needed for the following reasons:
The headhouses will be designed in order to minimise their visual impact on the local area. For example, materials are being chosen to complement the surrounding environment in agreement with the local council.
In February 2011, we embarked upon a seven-year, £1bn infrastructure project to rewire the Capital, the first major investment in the electricity transmission system in London since the 1960s. The project, known as London Power Tunnels, saw the construction of 32kms of underground tunnels, running from Hackney in the east to Willesden in the west, and from Kensal Green to Wimbledon in the south. The newly built 10 transmission circuits can now carry some 20% of the Capital’s electricity demand and stretched out they would run all the way around the M25.
Key facts about London Power Tunnels phase 1
If you would like to discuss the project in greater detail or have any questions, please contact our community relations team using the details below:
Call our Freephone helpline number: 0800 783 2855 (lines open 9am to 5pm, Monday to Friday)
Email: [email protected]
Write to: FREEPOST NATIONAL GRID