UK-based High Speed Two (HS2) has announced the first tunnelling breakthrough along the London to Birmingham route.

Using a 2,000t custom-made tunnel boring machine (TBM) called Dorothy, the firm has concluded a one-mile dig under Long Itchington Wood in Warwickshire.

It is the first of 64 miles of intricate tunnels under Europe’s largest infrastructure project. The tunnel will span intermittently between London and Manchester.

The 125m long TBM commenced its operation at the tunnel’s North Portal in December 2021 and reached the South Portal site on 22 July.

Around 400 people working for HS2’s main works civil contractor, Balfour Beatty VINCI (BBV JV) have been involved in the tunnelling breakthrough works, which were completed in seven months.

The tunnel is designed to protect the ancient woodland above, which is classified as a Site of Special Scientific Interest (SSSI). It features complex ecosystems that took hundreds of years to grow.

HS2 CEO Mark Thurston said: “This is a historic moment for the HS2 project, and I’d like to congratulate everyone involved in delivering it.

“The 400-strong team, including tunnelling engineers, TBM operators, and the construction workers at both portal sites, have pulled out all the stops to achieve this fantastic milestone.”

Earlier this month, HS2 started construction on the 450m-long Wendover Dean Viaduct, which is said to be Britain’s first key rail bridge to be built with a double composite structure.

HS2 is expected to play a significant part in the government’s £96bn Integrated Rail Plan, which includes the development of three new high-speed lines, addition of extra seats, and reduction in travel times.