HS2, which is at peak construction, has now completed excavation of two of its five twin-bore tunnels, with a further two well under way.

The high-speed rail line is being constructed at 350 separate worksites between London and the West Midlands. It is supporting more than 31,000 jobs.

HS2 says new analysis published today shows that 46.7km – 53% – of the 88.2km of tunnels has been excavated and built so far, eclipsing the length of tunnels bored for the Crossrail line in London.

In March last year, TBM Dorothy completed its second drive of the 1.6km Long Itchington Wood Tunnel in Warwickshire – the first tunnel to be completed on the project.

Earlier this year, TBMs Florence and Cecilia completed both drives of the 16.1km Chiltern Tunnel – the longest tunnel on the route.

In London, four TBMs are digging the 13.5km Northolt Tunnel. TBMs Sushila and Caroline have excavated around 4.8km of their 8km route, travelling from West Ruislip to Green Park Way in Greenford, north-west London. Two more TBMs are building a 5.5km section of this tunnel in the opposite direction from Victoria Road in Ealing to Green Park Way. TBM Emily has completed 320m and TBM Anne has just been launched.

In the Midlands, TBM Mary Ann is nearly 3km into the 5.6km drive of the first bore of the Bromford Tunnel between Water Orton in North Warwickshire and Washwood Heath in Birmingham. TBM Elizabeth has just started to build the second bore.

The TBMs are advancing at an average speed of 12-16m per day.

Once the drives are finished, HS2 moves to the next stage of the tunnelling project when other aspects such as the cross-passages, vent shafts and portals will be completed.

Rail minister Huw Merriman said reaching the milestone on a project of HS2’s scale showed how much momentum was behind construction of the line.

“It’s a significant achievement for the team helping deliver this railway and I’m delighted the project has now supported record numbers of new jobs, demonstrating the vital role it is playing in creating opportunities up and down the country,” he said.

Preparatory works have been completed ahead of the formal start of the 7.2km Euston Tunnel between Old Oak Common and Euston station in London. The two TBMs are currently being manufactured and tested. The government is exploring different funding mechanisms for delivery of the tunnel.

Yesterday the Financial Times reported that HS2 was set to get the go-ahead for the Euston Tunnel in the next few weeks, with the government to release more than £1bn for the work.