Tunnelling has started for a new river crossing in east London.
Transport for London (TfL) announced that a tunnel boring machine (TBM) has been launched at Royal Docks to excavate the 1.4km (0.9-mile) Silvertown Tunnel under the Thames.
Once it has completed the first tunnel by reaching the Greenwich peninsula, it will be turned around and directed back to Royal Docks to create the second tunnel.
Silvertown Tunnel is expected to open in 2025 and will be used by cars, vans, lorries and buses.
TfL said this will reduce congestion at Blackwall Tunnel.
Charges will be introduced for using both tunnels once Silvertown Tunnel opens.
The level of charges has not been determined.
TfL’s head of the Silvertown Tunnel programme Helen Wright said: “The start of tunnelling is a huge step forward for this project and we are committed to working hard to ensure that it is delivered with minimal impact to Londoners.
“As well as reducing congestion and providing better cross-river bus opportunities, the new tunnel will also help deliver a wide range of local improvements, including dedicated walking and cycling infrastructure and new landscaping.
“We are working actively on these designs and we hope we can share these with local residents and stakeholders shortly, ahead of starting work on them within the next year.”
It has secured £1.2 billion of private finance to build, operate and maintain the tunnel.
TfL’s accounts indicate that the transport body’s total repayments over a 25-year period could exceed £2 billion.
The TBM is 82 metres long and has a cutter face with a diameter of 11.9 metres.
It has been named Jill in honour of Jill Viner, the capital’s first female bus driver.
The machine was manufactured by German company Herrenknecht before being transported to London in pieces.
It was reassembled in the launch chamber in Royal Docks.
Nearly 600,000 tonnes of material will be excavated during the project.
This will be removed via barges on the Thames to minimise construction traffic on local roads.
The material will be sent to a former landfill site in Essex as part of a restoration scheme.