December 20, 2025
Mind the volts!
A train-sized tunnel is now carrying electricity under South London
London’s underground power ‘Tube’ sparks awe, zig‑zag theories, and London‑bias rage
TLDR: A new 18km deep tunnel now carries power under South London as part of a £1bn upgrade. Commenters marvel at the engineering, rage about London‑first spending, and puzzle over the zig‑zag cable layout and wall‑mounted cables without classic insulators — the power flows, the debate crackles.
London just flipped the switch on a train‑sized tunnel that carries electricity under South London — and the comments are buzzing louder than the cables. The first of two new circuits now runs 18km, up to 50 metres deep, linking New Cross to Hurst, part of the £1 billion London Power Tunnels 2 project stretching 32.5km across seven boroughs from Wimbledon to Hurst. It replaces 1960s street‑buried lines, with the second circuit due in the new year. And yes, it’s literally a Tube for electrons.
Cue community chaos. One camp is wide‑eyed: “Impressive” and wondering why superconducting cables aren’t here yet, with theories about cryogenic cooling being a nightmare in tight tunnels. Another camp is obsessing over the photo: why the zig‑zag pattern? Heat? Vibration? Magnetic fields? Or just to stop engineers from tripping — and gremlin deterrent memes were flying. Practical skeptics point out overhead lines use stacks of ceramic insulators, while these beefy cables… just hang on the wall?!
Then the flame war: is this proof of London‑first spending? One commenter roasted the “too expensive elsewhere” excuse, while another clapped back that overhead rights‑of‑way in London are basically impossible, so underground is the only option. The power’s on — and the takes are sizzling.
Key Points
- •The first of two underground power circuits between New Cross (Southwark) and Hurst (Bexley) is now live, running 18km and up to 50m deep.
- •The new link replaces one of two buried cables from the 1960s; the second circuit will replace the remaining cable in the new year.
- •The LPT2 project carries power in three-metre-wide tunnels deep beneath South London’s road network.
- •London Power Tunnels 2 is a £1 billion project begun in 2019, spanning 32.5km across seven South London boroughs from Wimbledon to Hurst.
- •Tunnelling occurred in three sections: Wimbledon–New Cross (12km), New Cross–Hurst (18km), and Hurst–Crayford (2.5km); it follows a £1bn North London phase completed in 2018.