High Speed 2 (HS2) Phase 1 Civil Works
London to West Midlands, UK · 2020–2039 · £87.7bn - £102.7bn (mixed price base)
The judgement call
Account-gated at launchInitial construction started in 2020 without completed designs, leading to significant inefficiencies and cost increases. - Contracts awarded for construction failed to drive optimal performance, contributing to delays and budget overruns. - The project underwent a significant 'reset' to establish a more rigorous cost and schedule foundation based on real-world delivery data and independent expert review. - Decision to marginally reduce maximum operating speed from 360kph to 320kph to align with European standards and facilitate testing on existing lines, impacting journey times minimally.
Key engineering challenges
Constructing extensive twin-bore and deep-bore tunnels through complex geology and under existing urban and natural environments. - Designing and building large-scale viaducts and bridges, such as the Colne Valley Viaduct, requiring innovative construction methods and environmental considerations. - Managing the immense scale and complexity of civil engineering works across hundreds of active sites, including significant earthworks and ground stabilization. - Integrating design and construction teams through Early Contractor Involvement (ECI) to manage project development and delivery across multiple contract packages.
Project facts
- Client / owner
- High Speed Two (HS2) Limited
- Lead contractor
- Balfour Beatty VINCI (BBV) JV (Lots N1 & N2); Skanska (Euston tunnels); EKFB JV (Eiffage, Kier, Ferrovial Construction, BAM Nuttall)
- Lead designers
- CH2M, Atkins, SENER (engineering delivery partner); Mott MacDonald Systra (MSD JV); WSP (Old Oak Common station)
- Project type
- new build
- Scale
- 51.4km twin-bore tunnels; 90km route (BBV); Colne Valley Viaduct (longest railway bridge); 23 miles deep-bore tunnels (Old Oak Common to Birmingham Curzon Street)
- Disciplines
- civil; structural; geotechnical; environmental; tunnelling; project management; systems; logistics
- Standards & frameworks
- NEC3; CDM 2015; RSSB standards
Sources: HS2.org.uk (https://www.hs2.org.uk/what-is-hs2/hs2-project-update/); New Civil Engineer (Jan 2024, https://www.newcivilengineer.com/latest/hs2-chief-says-governments-inability-to-afford-construction-schedule-contributed-to-overruns-10-01-2024/); NEC Contract (Nov 2015, https://www.neccontract.com/news/uk-government-launches-nec-contracts-for-high-speed-two?srsltid=AfmBOorkmgDU4w6WuTgbYlarzpY4nvYXESTJViBCxDI0U5ejGGy_hFpw); HS2 Learning Legacy (Oct 2021, https://learninglegacy.hs2.org.uk/document/innovative-approach-to-cdm-coordination/)