Power Lines Underground Project


Powerlines Underground Key Facts
  • £250m, 1.5 million man-hours and 420 workers on site.
Pylons removed
  • 52
Total tunnel length
  • 4 tunnels totalling 13km in length
Total length of power cable installed
  • 200km
Depth below ground
  • 20-30m
Tunnel boring machines
  • 4 - 2x4.0m diameter and 2x2.5m diameter.
Duration of dig
  • 424 days
  • 80km of overhead cable and 8 tonnes of porcelain insulators were all 100% recycled
Tunnelling spoil
  • 175,000 cubic metres of spoil was produced by the tunnel boring machines, 90% of which was used on the Olympic Site for earthworks.

Below is a case study document explaining the project in more detail:

Power Lines Underground Case Study