The UK’s HS2 has announced a significant milestone at Long Itchington Wood Tunnel in Warwickshire – the first deep tunnel on the high-speed route to complete its civil engineering phase.
The development at the 1.6km twin-bore tunnel – which will carry the railway into the West Midlands – sees vital elements, including three cross passages, concrete finishing works and base slabs, and emergency and maintenance walkways complete.
It comes before the internal fitting out of the tunnel with the complex systems needed to operate the high-speed line including the power, track and signalling.
The tunnel is the first of five twin-bore tunnels on the HS2 project to reach this vital stage. In all, 43,8km of the route between London and the West Midlands are in deep, twin-bore tunnels.
Work to create the Long Itchington Wood Tunnel initially began in June 2020. The 125m long TBM was launched in December 2021 and finished excavating both bores of the tunnel by March 2023.
The process to fully excavate two tunnel drives and the entrance sections produced around 750,000 tonnes of material, which has since been reused to build embankments along the route of the railway. Since the breakthrough almost two years’ ago, work has been ongoing to fit out the tunnels with its structural components.
The tunnel is being built by HS2’s main works contractor for the West Midlands, Balfour Beatty VINCI (BBV), which is constructing 89.6km of HS2 between Long Itchington in Warwickshire to the centre of Birmingham and on to Staffordshire.
Jules Arlaud, Tunnelling Director for Balfour Beatty VINCI, said: “The scale of this achievement is enormous. A dedicated workforce of around 380 people have worked tirelessly over the past five years to reach this latest phase of construction, where the tunnels are now fitted with three cross-passages and the concrete finishing works, base slabs, and walkways are also complete.
“Throughout this project, our expert tunnelling team have installed a total of 1,582 concrete rings across both tunnels, with each ring made from eight two-metre-wide segments, each weighing up to 8 tonnes.”
Construction of HS2 continues between the West Midlands and London, with the programme now supporting over 31,000 jobs. When complete, HS2 services will run between London and the West Midlands on a dedicated high-speed line before reaching destinations further north – creating economic growth and freeing up space for more local trains on the most congested part of the existing West Coast Main Line.
In recent weeks, construction progress in the West Midlands has seen HS2 complete its first viaduct at HS2’s Delta Junction in North Warwickshire. HS2 has also revealed the latest progress on a new green bridge set to cross the high-speed railway near Kenilworth, Warwickshire.
The four other twin bore tunnels on HS2 are:
The 5.6km Bromford Tunnel which carries the railway into Birmingham, with both tunnel drives expected to be completed this year.
The 16km long Chiltern Tunnel – HS2’s longest, which takes the railway beneath the Chiltern Hills – with both tunnel drives being completed in early 2024 and internal works on the tunnels now ongoing;
The Northolt Tunnel – an 13.4km tunnel between Old Oak Common and outer London – which is being built by four tunnelling machines, with the first drive completed in December last year;
The 7.2km Euston Tunnel between Old Oak Common and central London which is at an advanced preparation stage before the launch of TBMs.
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