The majority of HS2’s deep tunnel drives and earthworks have been completed.
A construction update published by HS2 Ltd reveals that 70% of twin-bore tunnels have been excavated, representing 61km of the 88.5km being built for the high-speed railway.
In all, five of the 12 tunnel drives have been completed. The most recent was the breakthrough by TBM Sushila, the first of four TBMs building the Northolt Tunnel in north-west London, which finished her drive on December 19.
The tunnelling completion tally also includes the breakthrough earlier this year of the 16km Chiltern Tunnel – the longest and deepest on the 225km line between London and Birmingham.
Progress has also been made on the six cut-and-cover – or green – tunnels. The 700m tunnel near Burton Green in Warwickshire passed the halfway mark in November.
Despite the recent progress, HS2 continues to face significant challenges, particularly over cost. HS2 Ltd chief executive Mark Wild, who joined the company in December, is leading a wide-ranging review of the programme which will be published this year.
His work will lead to a full reset of HS2 to provide certainty over cost and schedule to the government. Wild set out HS2’s challenges in evidence to the Commons Public Accounts Committee on December 19.
“HS2 represents a significant investment in Britain’s future and in the last month I’ve been inspired by the hugely impressive feats of civil engineering taking shape right along the route. New railways provide better journeys and they boost economic growth by fuelling investment in communities and businesses,” he said.
“The prize is clear. However, the programme is in a very serious situation that requires a fundamental reset to enable it to be delivered to the lowest feasible cost. I am committed to delivering this reset over the coming year to ensure the railway can be brought into service safely and efficiently.”
This year this UK will celebrate 200 years of the railway and HS2 says the bicentenary provides an historical backdrop to continuing construction of HS2 – the latest and most advanced addition to the country’s rail network.
More than 31,000 people are currently employed on the project, with 350 active construction sites along the length of the route.
This year HS2 expects to achieve several construction milestones. They include completion of:
- excavation of the 13.5km Northolt Tunnel – the second longest on the line – with three TBMs breaking through, in addition to the one in December;
- both bores of the 5.6km Bromford Tunnel – a critical section of the railway which will carry the line in and out of Birmingham;
- the base slab of Old Oak Common’s underground station box, alongside the start of work on the station platforms;
- the Copthall tunnel – a 900m green tunnel on the outskirts of London between the Northolt Tunnel and the Colne Valley Viaduct.
