HS2 Launches Karen Harrison TBM 4.5-Mile Drive to Euston

LONDON, UK – High Speed 2 (HS2) has launched its final Tunnel Boring Machine for the project’s first phase, beginning the excavation of the last major tunnel section into Central London. Named in honour of pioneering female train driver Karen Harrison, the TBM will dig a 4.5-mile route from the Old Oak Common super-hub station site towards Euston. The launch represents a significant construction milestone for the high-speed line connecting London to the West Midlands.

What Is the Full Scope of This Project?

The Euston Tunnel project involves two TBMs, ‘Karen Harrison’ and its counterpart ‘Madge’, excavating twin-bore tunnels to create the final approach for HS2 services into the planned Euston terminus. This section is being delivered by the Skanska Costain STRABAG Joint Venture (SCS JV), which manages a workforce of approximately 30,000 people across the entire HS2 project. While construction progresses, the final design and delivery schedule for the Euston station itself remain under review following a UK government directive to find ways to reduce costs and manage delays on this complex final section.

Key Project Data

How Does This Compare to Similar Projects?

The scale of the HS2 TBMs contrasts sharply with other high-profile tunnelling initiatives, such as those by Elon Musk’s The Boring Company. The HS2 machines have a large diameter of approximately 9.1 metres, required for heavy rail infrastructure, and operate as self-contained “moving factories” that install concrete tunnel lining segments as they excavate. In comparison, The Boring Company’s machines used for projects like the Las Vegas Convention Center Loop or a proposed Baltimore-Washington tunnel have a much smaller diameter of around 3.7 metres, designed for electric vehicles in a lower-capacity transit system. (Source: The Boring Company, 2023). While both are TBMs, the HS2 project represents a far larger and more complex civil engineering undertaking typical for national high-speed rail networks.

Editor’s Analysis

The launch of the final TBM is a crucial operational success for HS2, demonstrating tangible progress on a project facing continuous political and financial scrutiny. However, this milestone on the tunnel drive highlights the unresolved challenges at its destination, as the Euston station’s scope and schedule remain the project’s most significant variable. This situation reflects a broader trend of high-cost, long-duration infrastructure delivery in Western markets, contrasting with the rapid, state-funded expansion seen in China, which invested over 700 billion yuan in rail infrastructure in 2018 alone. (Source: Statista, 2022).

FAQ

Q: Who was Karen Harrison?
A: Karen Harrison was one of the United Kingdom’s first female train drivers, joining British Rail in 1979. She was a trailblazer who faced significant opposition and paved the way for women to enter the profession.

Q: What is the total length of tunnels on HS2 Phase One?
A: There are a total of 32 miles of twin-bore tunnels on the Phase One route between London and the West Midlands. The 4.5-mile Euston tunnel is the final major section to begin construction.

Q: Will this TBM launch speed up the opening of HS2 to Euston?
A: While the tunnel construction is a critical step, the overall opening date for services to Euston is dependent on the final design, funding, and construction schedule for the Euston station itself. This has not been officially confirmed by the UK government.