HS2 Urban Tunnels in London

Tunnel infrastructure for London's high-speed railway

In London, the Skanska Costain STRABAG joint venture (SCS JV) is executing two major design- and-build contracts for the Euston and Northolt Tunnel approaches on behalf of HS2. This high-profile infrastructure project involves constructing 48 kilometres of twin-bore tunnels for a high-speed railway utilising seven tunnel boring machines and multi-discipline civil engineering works.

Executing such a massive scheme in suburban and central London requires minimising ecological and community impacts. To overcome inner-city logistics challenges, the SCS JV established a nine-mile conveyor system spanning rail bridges, roads and canals. This network transports excavated material from Old Oak Common station to a dedicated logistics hub, where trains carry the soil out of the city to construct embankments and refill a former quarry site in Cambridgeshire. This rail-based transport strategy eliminates heavy goods vehicles, reduces local traffic and lowers C02 emissions. Furthermore, a specialist logistics tunnel links the hub and Old Oak Common station to supply materials for the Euston Tunnel away from local roads.

Pioneering technologies decrease the impact of construction on local communities. The team deployed an AI Mud Cam using video analytics to detect mud on roads. Due to this, teams can mitigate safety risks caused by the build-up of mud and debris. Another innovation is a new technique for removing waste concrete from piles, which substantially reduces noise and dust emissions in surrounding residential areas.

Scope of Work

• Design and planning 
• Tunnel boring and construction 
• Civil engineering works 
• Logistics and transport infrastructure construction 
• Environmental monitoring and mitigation