Work continues on a massive project to add new underground transmission capacity to South London.
In Spring 2020 the UK's National Grid embarked on a seven year, £1 billion ($1.27 billion) project, to rewire South London via deep underground tunnels. This essential upgrade will help keep the population of Britain's capital city connected to sufficient electricity supplies to ensure reliability in the face of increasing demand.
Phase 2 of the project is a new cable tunnel, 32.5km in length, between Wimbledon in the South West of London and Crayford in the South East, which will carry high voltage electricity cables.
Most of the electricity supply in South London is currently transmitted through underground cables, usually running just below the highways. Maintenance work often involves digging up the roads, which is highly disruptive to traffic, and obviously impacts on businesses in the generally-congested road network.
By sinking the new electricity cables in deep underground tunnels, there will be a number of benefits:
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Lower disruption during construction as the majority of works will take place deep underground
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Future repairs and maintenance work can be carried out without disrupting either traffic, residents or businesses
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Additional cables can be installed in the tunnels to meet future demand
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.
Phase 1 built tunnels between 20 and 60 meters underground, deploying 400kV and 132kV cables. The tunnels go under subway lines, canals and rivers. Using a workforce of over 700 people at the busiest time on the project, and forty apprenticeship tunnelling roles were created over the project’s lifespan. In total, it took over 6 million people hours to complete LPT Phase 1.
This ambitious project is necessary to build the transmission infrastructure to supply the electricity needs of Londoners for the future.