The giant machines digging the main Thames Tideway tunnel have now bored over 13km of the 25km total length.

The tunnel now stretches as far west as Fulham and, eastwards, it has reached Blackfriars in the City of London – passing under 13 bridges including Albert Bridge, Westminster Bridge and Waterloo Bridge.

TBM Rachel digging the west section has passed the 3km mark on her 7km journey from Fulham to Acton.

So far, the tunnels have been constructed using four tunnel boring machines.

Two more tunnelling machines are due to start working in east London this year, creating the eastern section of the main tunnel from Bermondsey to Newham, as well as a slightly smaller 4km connection tunnel in Greenwich.

The project is looking to develop innovative ways of works and has introduced pre-shift work-outs to help prevent musculoskeletal disorders at Thames Tideway.

Tunnel team’s ‘stretch and flex’ sessions at the beginning of shifts, enabling engineers, site managers and drivers alike to prepare for the day’s tasks while getting a little bit of exercise in the process.

Andy Mitchell, Tideway CEO, said: “After more than three years of exceptional work by our teams across London, we’ve reached the halfway mark on the super sewer.

“There’s still a way to go but reaching this point on schedule is testament to the success of the team, who have achieved a huge number of engineering feats – including tunnelling under the river through a variety of ground conditions, building new pieces of land in the Thames to work in and digging giant shafts up to 50m deep below London.

Secondary lining for a 60m-deep shaft built in Bermondsey is now complete using 4,000 cu m of slip-formed concrete

“Once complete, not only will we have a cleaner river but there will be seven new areas of public space created along the Thames, transforming the embankment and creating new areas for Londoners and visitors to reconnect with the river.”

As well as the main tunnel, a 1km connection tunnel is also currently under construction in Wandsworth.

Three million tonnes of excavated material have been transported by river, avoiding 340,000 HGV journeys

Tunnelling is due to complete in 2022, allowing up to two years of commissioning for a March 2024 opening.