TBM Sushila - HS2 Northolt Tunnel West
West London, UK (Old Oak Common to Ruislip) · 2022-2025 (Started October 2022, completed March 2025) · £87.7bn - £102.7bn (HS2 project total, 2025 prices)
The judgement call
Account-gated at launchTBM Sushila took two years to bore its section of the Northolt Tunnel. It was one of four TBMs used for the Northolt Tunnel. Named after Sushila Hirani, a local teacher.
Key engineering challenges
Tunnelling under densely populated urban areas. - Managing ground movements and settlement. - Excavating 34 cross passages.
Project facts
- Client / owner
- HS2 Ltd.
- Lead contractor
- SCS JV (Skanska Costain STRABAG Joint Venture)
- Lead designers
- —
- Project type
- new build
- Scale
- Tunnel length: 13.5 km (8.4 miles) twin-bore tunnel; Drive length: 8km (5 miles)
- Disciplines
- civil; structural; mechanical; electrical; systems; tunnelling; geotechnical
- Standards & frameworks
- UK railway standards, CDM Regulations (implied).
Sources: GEplus.co.uk (https://www.geplus.co.uk/news/hs2-first-tbm-ends-northolt-tunnel-bore-in-reception-can-23-12-2024/) - LinkedIn (https://www.linkedin.com/posts/british-tunnelling-society_hs2-tbm-retrieved-after-building-london-tunnel-activity-7308049798354337792-axew) - Tunnelling Journal (https://tunnellingjournal.com/hs2-lifts-out-second-northolt-tbm/) - HS2.org.uk (https://www.hs2.org.uk/work-items/update-atlas-road-logistics-tunnel-works/)