The enormous tunnelling machine known as 'Dorothy' has finally been lifted to the surface after completing its mission to carve out tunnels for the controversial HS2 high-speed rail project. The colossal 2,000-tonne machine finished its 10-mile journey beneath London, marking a significant milestone in the UK's most expensive infrastructure endeavour.
A Colossal Engineering Feat
Standing at 170 metres long, Dorothy represents one of the most impressive pieces of engineering in modern British infrastructure projects. The machine spent three years boring through London's clay to create twin tunnels that will eventually carry high-speed trains between the capital and the Midlands.
The End of an Underground Odyssey
Workers cheered as the giant machine's cutterhead emerged into daylight for the first time since 2021. The breakthrough moment came at HS2's Northolt tunnel site in West London, where engineers will now begin dismantling the massive apparatus piece by piece.
Why HS2's Costs Keep Rising
The extraction of Dorothy highlights the extraordinary complexity of the HS2 project, which has seen its budget balloon to an estimated £71 billion. Observers note that the sheer scale of machinery involved helps explain the project's staggering costs.
- Each tunnelling machine costs approximately £10 million
- The Northolt tunnels required 56,000 concrete segments
- Dorothy removed enough spoil to fill 4,500 Olympic swimming pools
What Comes Next for HS2?
With this tunnelling phase complete, attention now turns to fitting out the tunnels and continuing work on other sections of the route. However, the project remains mired in controversy over its environmental impact and value for money.
Transport Secretary Mark Harper hailed the achievement as "a testament to British engineering", while critics continue to question whether the benefits justify the extraordinary expenditure.
