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Update on Northolt Tunnel construction in Hillingdon and Ealing

Work item: HS2-SCS-25-1287

Work Item Summary

Project Phase
Phase 1
Region
Brent and Ealing, Hillingdon
Contractor
SCS JV
Type of works
Concrete break out, Construction
Estimated Start Date
02/09/2025
Estimated End Date
28/02/2026

What we are doing

Construction of the 8.4 mile (13.5km) long twin-bore Northolt Tunnel is complete between Old Oak Common and West Ruislip.

We are now building the emergency and maintenance walkways inside the tunnel and creating the connections between the tunnel and the South Ruislip and Mandeville Road ventilation shaft.

  • 24/7 walkway construction works inside the twin bore tunnel until February 2026.
  • South Ruislip Ventilation Shaft – 24/7 works to connect the tunnel to the main shaft until 25 September 2025.
  • Mandeville Road Ventilation Shaft – 24/7 works tunnel main shaft expect to start on the 2 October until 31 October 2025.

We will update you should these dates change.

We are working inside the tunnel about 25 metres below ground. We are removing tunnel lining segments from the upper part of the tunnel and breaking out the
concrete between the tunnel and the bottom of the shaft. The broken concrete is then removed through the tunnel. To reduce night-time noise, we are restricting concrete cutting and drilling activities to between 8am and 10pm daily.

Download information relating to these works

Find out more about

If you have a question about HS2 or our works, please contact our HS2 Helpdesk team on 08081 434 434 or email [email protected]