HS2 Old Oak Common breakthrough: design and monitoring notes for tunnel engineers
Reviewed by Joe Ashwell
First reported on New Civil Engineer
30 Second Briefing
Skanska Costain Strabag’s London tunnels JV has completed breakthrough into Old Oak Common station, forming the full 14km HS2 tunnel link between the station box and the north London route. The excavation connects the Old Oak Common underground platforms to the mainline alignment towards Euston, allowing continuous fit-out of track, slab and M&E systems along the west London section. For geotechnical and structural teams, the breakthrough marks the transition from heavy tunnelling to lining, waterproofing and settlement monitoring around one of HS2’s most constrained urban interfaces.
Technical Brief
- Transition zone now shifts from TBM operations to secondary lining, waterproofing and internal structural works.
- Settlement monitoring focus moves to the station–tunnel junction, where stiffness contrasts and construction stages interact.
- Ventilation, emergency egress and fire-life-safety systems can now be designed and commissioned as a single continuous tunnel section.
Our Take
Old Oak Common features repeatedly in our HS2 coverage as the launch point for the Euston link tunnels, so this breakthrough on the 14 km section effectively ties the north London works into the central London tunnelling sequence driven by TBM “Madeleine” (28 January 2026 item).
The Skanska Costain Strabag (SCS) JV appears across several London‑tunnel pieces in our database as HS2’s core underground delivery vehicle, and the continuity of that role through management changes flagged in the 29 September 2026 article suggests relatively stable delivery capability on this multi‑billion‑pound package.
Versarien’s move into administration, noted in our December 2025 and January 2026 items, may limit near‑term deployment of graphene‑enhanced concrete on HS2, implying that innovative materials trials around Old Oak Common and the wider HS2 route could revert to more conventional specifications unless alternative partners step in.
Prepared by collating external sources, AI-assisted tools, and Geomechanics.io’s proprietary mining database, then reviewed for technical accuracy & edited by our geotechnical team.
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