Published: Friday 05 May 2023
I was fortunate to join a site to visit in late March to HS2’s Tunnel Boring Machine Visitor Centre, near Long Itchington, Warwickshire. This is the location of the HS2 twin-bore tunnel under Long Itchington Woods. These woods, and neighbouring Ufton Wood, are a single block of deciduous ancient woodland dating from at least 1600AD. They are classified as a Site of Special Scientific Interest, which for HS2, means a tunnel is needed to avoid disturbing this important asset.
This particular tunnel in Warwickshire forms part of HS2 Phase 1, which is the section of HS2 extending from London up to the West Midlands, with a terminus at Curzon Street in Birmingham City Centre, plus a link into the West Coast Main Line at Handsacre, near Lichfield. Later stages of the project will see the railway extend to Crewe (Phase 2a), then onto Manchester and the East Midlands (Phase 2b).
The twin bore tunnel under Long Itchington Woods is approximately one mile long. HS2 Ltd, working with Balfour Beatty Vinci JV, has used a Tunnel Boring Machine – an amazing bit of kit which does exactly what the name suggests. It slowly bores the tunnel, using a 10m diameter cutter head, while simultaneously lining the tunnel with concrete segments. But before dwelling on the detail, first a note on the name. This TBM is named ‘Dorothy’. Naming the machine after a woman follows a long tradition, dating back to the 1500s when miners prayed to Saint Barbara to protect them from the dangers underground. This particular machine is 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 paving the way for insulin to be used in treating diabetes.
At the time of my visit, ‘Dorothy’ had already bored the ‘down’ tunnel, which is the tunnel to be used by northbound trains from London to the West Midlands and beyond. This took approximately five months, with the TBM working 24 hours a day, seven days a week. Dorothy was now close to completing the ‘up’ tunnel (for trains in the London-bound direction). In fact, she was only a handful of days from breaking through at the southern portal, so the visit was clearly well-timed! The material excavated is converted from a solid, into a liquid slurry, before being converted back to a solid, with as much material as possible being used to support other parts of the build.
Once Dorothy has completed the ‘up’ tunnel at Long Itchington, she will be dismantled (with the cutter head being removed at the south portal, before the remainder of the TBM is dragged back through the newly lined tunnel to the north portal), before moving up to the Birmingham area to bore the Bromford tunnels. These are situated between the proposed HS2 Interchange Station, close to Birmingham Airport, and Curzon Street in the city centre. Here, the task is bigger than that at Long Itchington, with much longer twin bore tunnels required.
So that’s the visit, and now onto a request. It is great to see such progress on Phase 1, but there remains uncertainty around the future phasing of the scheme, including the date at which it will reach the East Midlands. Recently, our Chairman Sir John Peace called for the end of dithering on HS2. But why does the uncertainty cause us a headache? As an organisation, we have developed ‘Midlands Engine Rail’, our portfolio of rail schemes across our geography, including our flagship scheme, the Midlands Rail Hub. While getting people into HS2 isn’t Midlands Engine Rail’s sole raison d’être, it is certainly up there. For our pipeline of schemes to be developed, offering credible rail enhancements at what is a very modest sum of money, it relies upon us having clear visibility on how and when HS2 will be completed. This is of course about much more than just the railway – this is about the economic transformation of large parts of the Midlands and beyond.
To summarise, great progress on Phase 1, but let’s not take the foot off the pedal for subsequent phases. Or as Sir John Peace put it - ‘Don’t dither, don’t delay, deliver HS2 all the way’.
Andy Clark is a Senior Rail Programme Manager at Midlands Connect.