Long Itchington Wood tunnel
HS2's first Midlands tunnelling machine unveiled
Long Itchington Wood Tunnel is part of Phase One of the new high speed railway between Birmingham and London.
It will be a one-mile twin bore tunnel under the Long Itchington Wood – an ancient woodland – and is an important part of HS2’s environmental strategy to protect nature.
We will use one tunnel boring machine (TBM) to dig the tunnel. The machine is named ‘Dorothy’ after Dorothy Hodgkin, who in 1964 became the first British woman to win the Nobel Prize in Chemistry.
On Wednesday 20 October, the legendary music producer and rail enthusiast Pete Waterman visited HS2’s Long Itchington Wood Tunnel site in Warwickshire to unveil the name of the machine.
The tunnel boring machine will soon start on its journey south towards London to dig the tunnel.
Throughout 2021, our construction team has been preparing the North Portal site ahead of the launch the tunnel boring machine, including major earthworks and creation of the portal wall.
Around 150 engineers have been working on the TBM during its construction and assembly, and once launched, a team will work around the clock excavating the one-mile tunnel over a period of around six months.
When it breaks through at the south portal, the machine will be brought back to the launch site to dig a second tunnel, which will take a further six months. This will create the twin bore tunnel.
The final section will become a ‘green tunnel’ – also known as a cut and cover tunnel – where a soil ‘roof’ is built around the tunnel entrance to integrate the portal into the natural landscape.
At the peak of construction on the whole of Phase One, ten tunnel boring machines – each a self-contained underground factory – will work 24 hours a day, 7 days a week. Weighing up to 2,200 tonnes, each 170m long machine will bore and line the tunnels as they drive forward at speeds of around 15 metres per day.
Protecting Long Itchington’s ancient woodland
Long Itchington Wood and neighbouring Ufton Wood are a single block of ancient woodland dating from at least 1600AD.
They are a Site of Special Scientific Interest (SSSI) with very complex ecosystems that have taken hundreds of years to establish.
This is only one part of our environment programme. In the Midlands we’ve already planted over 340,000 trees and created 62 new habitat sites for wildlife which are already thriving.
Planting will continue over the next few years as we move towards our target of 7 million trees and shrubs on Phase One and hundreds of new spaces for wildlife and people to enjoy.
Long Itchington Wood Tunnel Facts and figures
- The tunnel boring machine weighs 2,000 tonnes
- TBM Dorothy is 125 metres long
- It will operate 24 /7 with a team working in shifts to keep it moving continually
- The tunnel boring machine will bore into the headwall which is 19m high
- After entering the headwall, it will dig a one-mile-long tunnel which will be 9.6m wide
- When it comes out the other side, TBM Dorothy will be brought back to the North Portal site to dig a second tunnel, just to the left of the first one
- Each tunnel will take around five months to dig
- The machine will remove a total of 250,000 cubic metres of mudstone and soil which will be transported to the slurry treatment plant where the material is separated out before being reused on landscaping along the route.
- Once the route is built and the track and signals are in place, trains will head north from London and will leave the tunnel here at 300km/h before passing between Coventry and Kenilworth.
Naming HS2’s giant tunnelling machines
On Wednesday 20 October, the legendary music producer and rail enthusiast Pete Waterman visited HS2’s Long Itchington Wood Tunnel site in Warwickshire to unveil the name of HS2’s first tunnel boring machine (TBM) on the northern section of Phase One.
During a ceremony on the construction site, Pete revealed that the TBM is called ‘Dorothy’ – named after Dorothy Hodgkin, who in 1964 became the first British woman to win the Nobel Prize in Chemistry. Her discoveries included confirming the structure of penicillin, and her work with insulin paved the way for it to be used on a large scale for treatment of diabetes.
This is the third HS2 tunnel boring machine to be named by public vote. The first two machines, which are due to start creating the tunnel under the Chilterns, were named after famous local Buckinghamshire women:
- Florence Nightingale – the founder of modern nursing who spent many years living in Buckinghamshire; and
- Cecilia Payne-Gaposchkin – a pioneering astronomer and astrophysicist, who was born in Buckinghamshire.