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
- 31/08/2026
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 late summer 2026.
- South Ruislip Ventilation Shaft – 24/5 reinforced concrete tunnelling works within the main shaft June 2026.
- Mandeville Road Ventilation Shaft – 24/5 works will continue until 14 November, followed by 24/7 tunnel connection works. We will update you on the dates for these works.
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]