A tube train sized tunnel has started being dug under south London running between Wimbledon and Crayford.
It’s not for trains though, as it’s part of the London Power Tunnels project to upgrade the electricity supply across London, and this new tunnel will be around 20 miles long when completed.
This new tunnel follows on from the original London Power Tunnels project, north of the Thames and will replace a maze of cables running under London’s streets which are wearing out and need replacing, but rather than digging up loads of roads, the National Grid has opted for a deep tunnel instead.
Tunnelling was due to start last year, but delayed due to you know what, and today the Tunnel Boring Machine was formally named Edith, to honour Edith Clarke, the first female electrical engineer and pioneer who used maths to improve the understanding of power transmission.
Now it’s been named, it will be lowered down a shaft at New Cross to start digging works in a few days time.
In addition to the tunnel, a number of shafts are also needed to be dug down, for access to the electricity tunnels, but mainly for ventilation to keep the cables cool. Once completed, the power tunnel will carry up to 400kV of electricity.