We need to carry out works at our existing substation at Hurst. We will need to build a shaft at the site to help dig the tunnel and remove excavated material. We will also need to build a headhouse which will cover the shaft. This will provide ventilation and access to the tunnel during construction and after.

The works should be carried out under our permitted development rights and will be agreed with the London Borough of Bexley.

Key facts:

  • Dimensions: The shaft will be 15m in diameter and approximately 35m in depth. The headhouse will have a maximum footprint of 15m by 15m and will reach a maximum height of 10m.
  • Working hours: 24-hour working would be required while we build the tunnel. Above ground work would take place from 7am to 5pm Monday to Friday, and 8am to 1pm on Saturdays. During the night our works will largely take place below ground. There would be no work on Sundays or Bank Holidays. Occasional out of hours work may be necessary and we will keep you informed about this.
  • Traffic movements: We anticipate there will be approximately 64 HGV movements per day while we build the tunnel to Eltham. We anticipate there will be 58 HGV movements per day at peak times while we build the tunnel to Crayford.
  • Access: Our construction vehicles will use Stable Lane/Vicarage Road to enter and leave the site, before joining the A20 and/or A2. We are also considering the design and location of a temporary haul route connecting to the A223, which would avoid using Stable Lane/Vicarage Road. This is subject to landowner agreement and planning consent.


  • We plan to start works in January 2021 until December 2025.
  • The tunnel to Eltham will be built between January 2021 and December 2022.
  • The tunnel to Crayford will be built between January 2023 and September 2023.
  • The headhouse will be built between January 2025 and June 2025.
Drawing of proposed headhouse.